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Astronomical and Space Sciences | Stellar Astronomy and Planetary Systems | Galactic Astronomy | Cosmology and Extragalactic Astronomy | Astronomical and Space Instrumentation | Astronomy And Astrophysics |
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Publisher: Oxford University Press (OUP)
Date: 03-05-2006
Publisher: MDPI AG
Date: 23-03-2023
Abstract: The COVID-19 pandemic has drawn attention to the health-promoting features of human-animal relationships, particularly for families with children. Despite this, the World Health Organization’s (1986) Ottawa Charter remains human-centric. Given the reciprocal health impacts of human-animal relationships, this paper aims to (i) describe perceived pet-related benefits, worries, and family activities and to (ii) examine differences in perceived benefits, worries, and activities for parents and children with and without clinical mental health symptoms. We recruited 1034 Australian parents with a child 18 years and a cat or dog via a national online survey between July and October 2020. Most parents reported their pet was helpful for their own (78%) and their child’s mental health (80%). Adjusted logistic regression revealed parents with clinical psychological distress were 2.5 times more likely to be worried about their pet’s care, well-being, and behaviour (OR = 2.56, p 0.001). Clinically anxious children were almost twice as likely to live in a family who engages frequently in pet-related activities (e.g., cooked treats, taught tricks, OR = 1.82, p 0.01). Mental health and perceived benefits of having a pet were not strongly associated. Data support re-framing the Ottawa Charter to encompass human-animal relationships, which is an often-neglected aspect of a socioecological approach to health.
Publisher: Oxford University Press (OUP)
Date: 07-09-2019
Abstract: As an introduction of a kinematic survey of Magellanic Cloud (MC) star clusters, we report on the dynamical masses and mass-to-light ratios (M/L) of NGC 419 (Small Magellanic Cloud) and NGC 1846 (Large Magellanic Cloud). We have obtained more than one hundred high-resolution stellar spectra in and around each cluster using the multi-object spectrograph M2FS on the Magellan/Clay Telescope. Line-of-sight velocities and positions of the stars observed in each cluster were used as input to an expectation-maximization algorithm used to estimate cluster membership probabilities, resulting in s les of 46 and 52 likely members (PM ≥ 50 per cent) in NGC 419 and NGC 1846, respectively. This process employed single-mass King models constrained by the structural parameters of the clusters and provided self-consistent dynamical mass estimates for both clusters. Our best-fitting results show that NGC 419 has a projected central velocity dispersion of $2.44^{+0.37}_{-0.21}$ km s−1, corresponding to a total mass of $7.6^{+2.5}_{-1.3}\\times 10^4\\ {\\rm M}_{\\odot }$ and V-band M/L ratio of $0.22^{+0.08}_{-0.05}$ in solar units. For NGC 1846, the corresponding results are $2.04^{+0.28}_{-0.24}$ km s−1, $5.4^{+1.5}_{-1.4}\\times 10^4\\ {\\rm M}_{\\odot }$, and $0.32^{+0.11}_{-0.11}$. The mean metallicities of NGC 419 and NGC 1846 are found to be $\\rm [Fe/H]=-0.84\\pm 0.19$ and −0.70 ± 0.08, respectively, based on the spectra of likely cluster members. We find marginal statistical evidence of rotation in both clusters, though in neither cluster does rotation alter our mass estimates significantly. We critically compare our findings with those of previous kinematic studies of these two clusters in order to evaluate the consistency of our observational results and analytic tools.
Publisher: Wiley
Date: 20-08-2016
DOI: 10.1016/J.ADOLESCENCE.2016.08.002
Abstract: This paper outlines the development and validation of the Adolescent Functioning Scale (AFS) in an Australian s le of parents of young people aged 11–18 years ( N = 278). The AFS, a parent self‐report measure, was designed to assess problem behavior and positive development in adolescents. Principal components analysis produced a 33‐item measure comprising four subscales: Positive Development, Oppositional Defiant Behavior, Antisocial Behavior and Emotional Difficulties. Convergent validity was established via correlations between the AFS and established measures of adolescent functioning and parenting, and discriminant validity was shown through no association between the AFS and a measure of technology use. Internal consistency for the subscales was high ( H = .82–.92 for different age groups), as was test‐retest reliability ( r = .77–.86). The study indicated that the AFS is a potentially valuable tool for assessing levels of problem behaviors and positive development in adolescents.
Publisher: Oxford University Press (OUP)
Date: 07-2016
Publisher: Cambridge University Press (CUP)
Date: 2019
DOI: 10.1017/PASA.2019.27
Abstract: We present the second data release (DR2) of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia, using six optical filters: u, v, g, r, i, z . DR2 is the first release to go beyond the $\\sim\\!18$ mag (10 $\\sigma$ ) limit of the Shallow Survey released in the first data release (DR1), and includes portions of the sky at full survey depth that reach $ \\!21$ mag in g and r filters. The DR2 photometry has a precision as measured by internal reproducibility of 1% in u and v , and 0.7% in griz . More than 21 000 $\\deg^2$ have data in some filters (at either Shallow or Main Survey depth) and over 7 000 $\\deg^2$ have deep Main Survey coverage in all six filters. Finally, about 18 000 $\\deg^2$ have Main Survey data in i and z filters, albeit not yet at full depth. The release contains over 120 000 images, as well as catalogues with over 500 million unique astrophysical objects and nearly 5 billion in idual detections. It also contains cross-matches with a range of external catalogues such as Gaia DR2, Pan-STARRS1 DR1, GALEX GUVcat, 2MASS, and AllWISE, as well as spectroscopic surveys such as 2MRS, GALAH, 6dFGS, and 2dFLenS.
Publisher: Public Library of Science (PLoS)
Date: 12-12-2013
Publisher: Oxford University Press (OUP)
Date: 12-02-2015
DOI: 10.1093/MNRAS/STV020
Publisher: Springer Science and Business Media LLC
Date: 22-02-2017
Publisher: American Astronomical Society
Date: 09-06-2010
Publisher: Cambridge University Press (CUP)
Date: 2018
DOI: 10.1017/PASA.2018.5
Abstract: We present the first data release of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia. Here, we present the survey strategy, data processing, catalogue construction, and database schema. The first data release dataset includes over 66 000 images from the Shallow Survey component, covering an area of 17 200 deg 2 in all six SkyMapper passbands uvgriz , while the full area covered by any passband exceeds 20 000 deg 2 . The catalogues contain over 285 million unique astrophysical objects, complete to roughly 18 mag in all bands. We compare our griz point-source photometry with Pan-STARRS1 first data release and note an RMS scatter of 2%. The internal reproducibility of SkyMapper photometry is on the order of 1%. Astrometric precision is better than 0.2 arcsec based on comparison with Gaia first data release. We describe the end-user database, through which data are presented to the world community, and provide some illustrative science queries.
Publisher: American Astronomical Society
Date: 26-04-2013
Publisher: Wiley
Date: 06-2017
DOI: 10.1002/JTS.22193
Abstract: This study investigated factors associated with acute stress symptoms in parents of seriously ill children across a range of illnesses and treatment settings within a pediatric hospital setting. It was hypothesized that psychosocial variables would be more strongly associated with acute stress responses than demographic and child illness variables. Participants were 115 mothers and 56 fathers of children treated within the oncology, cardiology, and intensive care departments of a pediatric hospital. Acute stress, psychosocial, demographic, and medical data were collected within the first 4 weeks of the child's hospital admission. A robust hierarchical regression model revealed that psychosocial factors significantly explained 36.8% of the variance in parent acute stress responses (p < .001) demographic variables significantly added a further 4.5% (p = .022), but illness-related factors did not contribute to the model. Findings support the implementation of a general psychosocial screening approach for parents across the wider hospital system, and that psychosocial risk factors may be targeted in interventions across different illnesses and treatment settings to improve parent outcomes.
Publisher: Oxford University Press (OUP)
Date: 14-12-2015
Publisher: Oxford University Press (OUP)
Date: 10-2018
Publisher: American Astronomical Society
Date: 10-2022
Abstract: We measure homogeneous distances to M31 and 38 associated stellar systems (−16.8 ≤ M V ≤ −6.0), using time-series observations of RR Lyrae stars taken as part of the Hubble Space Telescope Treasury Survey of M31 Satellites. From orbits of new/archival Advanced Camera for Surveys imaging, we identify RR Lyrae stars and determine their periods and mean magnitudes to a typical precision of 0.01 day and 0.04 mag. Based on period–Wesenheit–metallicity relationships consistent with the Gaia eDR3 distance scale, we uniformly measure heliocentric and M31-centric distances to a typical precision of ∼20 kpc (3%) and ∼10 kpc (8%), respectively. We revise the 3D structure of the M31 galactic ecosystem and: (i) confirm a highly anisotropic spatial distribution such that ∼80% of M31's satellites reside on the near side of M31 this feature is not easily explained by observational effects (ii) affirm the thin (rms 7–23 kpc) planar “arc” of satellites that comprises roughly half (15) of the galaxies within 300 kpc from M31 (iii) reassess the physical proximity of notable associations such as the NGC 147/185 pair and M33/AND xxii and (iv) illustrate challenges in tip-of-the-red-giant branch distances for galaxies with M V − 9.5, which can be biased by up to 35%. We emphasize the importance of RR Lyrae for accurate distances to faint galaxies that should be discovered by upcoming facilities (e.g., Rubin Observatory). We provide updated luminosities and sizes for our s le. Our distances will serve as the basis for future investigation of the star formation and orbital histories of the entire known M31 satellite system.
Publisher: Oxford University Press (OUP)
Date: 22-03-2022
Abstract: We explore the structural and kinematic properties of the outskirts of the Large Magellanic Cloud (LMC) using data from the Magellanic Edges Survey (MagES) and Gaia EDR3. Even at large galactocentric radii (8° & R & 11°), we find the north-eastern LMC disc is relatively unperturbed: its kinematics are consistent with a disc of inclination ∼36.5° and line-of-nodes position angle ∼145° east of north. In contrast, fields at similar radii in the southern and western disc are significantly perturbed from equilibrium, with non-zero radial and vertical velocities, and distances significantly in front of the disc plane implied by our north-eastern fields. We compare our observations to simple dynamical models of the Magellanic or Milky Way system which describe the LMC as a collection of tracer particles within a rigid potential, and the Small Magellanic Cloud (SMC) as a rigid Hernquist potential. A possible SMC crossing of the LMC disc plane ∼400 Myr ago, in combination with the LMC’s infall to the Milky Way potential, can qualitatively explain many of the perturbations in the outer disc. Additionally, we find the claw-like and arm-like structures south of the LMC have similar metallicities to the outer LMC disc ([Fe/H] ∼ −1), and are likely comprised of perturbed LMC disc material. The claw-like substructure is particularly disturbed, with out-of-plane velocities & km s−1 and apparent counter-rotation relative to the LMC’s disc motion. More detailed N-body models are necessary to elucidate the origin of these southern features, potentially requiring repeated interactions with the SMC prior to ∼1 Gyr ago.
Publisher: Oxford University Press (OUP)
Date: 26-04-2018
Publisher: Oxford University Press (OUP)
Date: 24-09-2014
Publisher: Oxford University Press (OUP)
Date: 07-03-2016
DOI: 10.1093/MNRAS/STW513
Publisher: Oxford University Press (OUP)
Date: 03-2002
Publisher: Public Library of Science (PLoS)
Date: 25-07-2022
DOI: 10.1371/JOURNAL.PONE.0271687
Abstract: Restrictions, social isolation, and uncertainty related to the global COVID-19 pandemic have disrupted the ways that parents and children maintain family routines, health, and wellbeing. Companion animals (pets) can be a critical source of comfort during traumatic experiences, although changes to family routines, such as those caused by COVID-19, can also bring about challenges like managing undesirable pet behaviours or pet-human interactions. We aimed to examine the relationship between pet attachment and mental health for both parents and their children during the COVID-19 pandemic in Australia. A total of 1,034 parents living with a child under 18 years and a cat or dog completed an online cross-sectional survey between July and October 2020. Path analysis using multivariate linear regression was conducted to examine associations between objective COVID-19 impacts, subjective worry about COVID-19, human-pet attachment, and mental health. After adjusting for core demographic factors, stronger pet-child attachment was associated with greater child anxiety (parent-reported, p .001). Parent-pet attachment was not associated with self-reported psychological distress ( p = .42), however, parents who reported a strong emotional closeness with their pet reported greater psychological distress ( p = .002). Findings highlight the role of pets during times of change and uncertainty. It is possible that families are turning to animals as a source of comfort, during a time when traditional social supports are less accessible. Alternatively, strong pet attachment is likely to reflect high levels of empathy, which might increase vulnerability to psychological distress. Longitudinal evidence is required to delineate the mechanisms underpinning pet attachment and mental health.
Publisher: American Astronomical Society
Date: 03-2022
Abstract: We report the kinematic, orbital, and chemical properties of 12 stellar streams with no evident progenitors using line-of-sight velocities and metallicities from the Southern Stellar Stream Spectroscopic Survey ( S 5 ), proper motions from Gaia EDR3, and distances derived from distance tracers or the literature. This data set provides the largest homogeneously analyzed set of streams with full 6D kinematics and metallicities. All streams have heliocentric distances between ∼10 and 50 kpc. The velocity and metallicity dispersions show that half of the stream progenitors were disrupted dwarf galaxies (DGs), while the other half originated from disrupted globular clusters (GCs), hereafter referred to as DG and GC streams. Based on the mean metallicities of the streams and the mass–metallicity relation, the luminosities of the progenitors of the DG streams range between those of Carina and Ursa Major I (−9.5 ≲ M V ≲ −5.5). Four of the six GC streams have mean metallicities of [Fe/H] −2, more metal poor than typical Milky Way (MW) GCs at similar distances. Interestingly, the 300S and Jet GC streams are the only streams on retrograde orbits in our dozen-stream s le. Finally, we compare the orbital properties of the streams with known DGs and GCs in the MW, finding several possible associations. Some streams appear to have been accreted with the recently discovered Gaia–Enceladus–Sausage system, and others suggest that GCs were formed in and accreted together with the progenitors of DG streams whose stellar masses are similar to those of Draco to Carina (∼10 5 –10 6 M ⊙ ).
Publisher: Oxford University Press (OUP)
Date: 12-10-2019
Abstract: We present an extensive study of the Sagittarius II (Sgr II) stellar system using MegaCam g and i photometry, narrow-band, metallicity-sensitive calcium H& K doublet photometry and Keck II/DEIMOS multiobject spectroscopy. We derive and refine the Sgr II structural and stellar properties inferred at the time of its discovery. The colour–magnitude diagram implies Sgr II is old (12.0 ± 0.5 Gyr) and metal poor. The CaHK photometry confirms the metal-poor nature of the satellite ([Fe/H] CaHK = −2.32 ± 0.04 dex) and suggests that Sgr II hosts more than one single stellar population ($\\sigma _\\mathrm{[FeH]}^\\mathrm{CaHK} = 0.11^{+0.05}_{-0.03}$ dex). Using the Ca infrared triplet measured from our highest signal-to-noise spectra, we confirm the metallicity and dispersion inferred from the Pristine photometric metallicities ([Fe/H]spectro = −2.23 ± 0.05 dex, $\\sigma _\\mathrm{[Fe/H]}^\\mathrm{spectro} = 0.10 ^{+0.06}_{-0.04}$ dex). The velocity dispersion of the system is found to be $\\sigma _{v} = 2.7^{+1.3}_{-1.0} {\\rm \\, km \\,\\, s^{-1}}$ after excluding two potential binary stars. Sgr II’s metallicity and absolute magnitude (MV = −5.7 ± 0.1 mag) place the system on the luminosity–metallicity relation of the Milky Way dwarf galaxies despite its small size. The low but resolved metallicity and velocity dispersions paint the picture of a slightly dark-matter-dominated satellite ($M/L = 23.0^{+32.8}_{-23.0}$ M⊙ L$^{-1}_{\\odot }$). Furthermore, using the Gaia Data Release 2, we constrain the orbit of the satellite and find an apocentre of $118.4 ^{+28.4}_{-23.7} {\\rm \\, kpc}$ and a pericentre of $54.8 ^{+3.3}_{-6.1} {\\rm \\, kpc}$. The orbit of Sgr II is consistent with the trailing arm of the Sgr stream and indicates that it is possibly a satellite of the Sgr dSph that was tidally stripped from the dwarf’s influence.
Publisher: Oxford University Press (OUP)
Date: 14-03-2018
DOI: 10.1093/MNRAS/STY661
Publisher: American Astronomical Society
Date: 02-12-2016
Publisher: Oxford University Press (OUP)
Date: 21-03-2009
Publisher: Oxford University Press (OUP)
Date: 03-10-2019
Abstract: We introduce the southern stellar stream spectroscopy survey (S5), an on-going program to map the kinematics and chemistry of stellar streams in the southern hemisphere. The initial focus of S5 has been spectroscopic observations of recently identified streams within the footprint of the dark energy survey (DES), with the eventual goal of surveying streams across the entire southern sky. Stellar streams are composed of material that has been tidally striped from dwarf galaxies and globular clusters and hence are excellent dynamical probes of the gravitational potential of the Milky Way, as well as providing a detailed snapshot of its accretion history. Observing with the 3.9 m Anglo-Australian Telescope’s 2-degree-Field fibre positioner and AAOmega spectrograph, and combining the precise photometry of DES DR1 with the superb proper motions from Gaia DR2, allows us to conduct an efficient spectroscopic survey to map these stellar streams. So far S5 has mapped nine DES streams and three streams outside of DES the former are the first spectroscopic observations of these recently discovered streams. In addition to the stream survey, we use spare fibres to undertake a Milky Way halo survey and a low-redshift galaxy survey. This paper presents an overview of the S5 program, describing the scientific motivation for the survey, target selection, observation strategy, data reduction, and survey validation. Finally, we describe early science results on stellar streams and Milky Way halo stars drawn from the survey. Updates on S5, including future public data releases, can be found at s5collab.github.io.
Publisher: Oxford University Press (OUP)
Date: 24-12-2016
Publisher: Oxford University Press (OUP)
Date: 08-09-2016
Publisher: Oxford University Press (OUP)
Date: 14-01-2019
DOI: 10.1093/MNRAS/STZ072
Publisher: Springer International Publishing
Date: 2018
Publisher: American Astronomical Society
Date: 07-2022
Abstract: We determine the detection limits of the search for dwarf galaxies in the Pan-Andromeda Archaeological Survey (PAndAS) using the algorithm developed by the PAndAS team. The recovery fractions of artificial dwarf galaxies are, as expected, a strong function of physical size and luminosity and, to a lesser extent, distance. We show that these recovery fractions vary strongly with location in the surveyed area because of varying levels of contamination from both the Milky Way foreground stars and the stellar halo of Andromeda. We therefore provide recovery fractions that are a function of size, luminosity, and location within the survey on a scale of ∼1 × 1 deg 2 (or ∼14 × 14 kpc 2 ). Overall, the effective surface brightness for a 50% detection rate ranges between 28 and 30 mag arcsec −2 . This is in line with expectations for a search that relies on photometric data that are as deep as the PAndAS survey. The derived detection limits are an essential ingredient on the path to constraining the global properties of Andromeda’s system of satellite dwarf galaxies and, more broadly, to providing constraints on dwarf galaxy formation and evolution in a cosmological context.
Publisher: Springer International Publishing
Date: 2018
Publisher: Springer New York
Date: 2019
DOI: 10.1007/978-1-4939-9161-7_9
Abstract: The ability to predict how mutations affect protein structure, folding, and flexibility can elucidate the molecular mechanisms leading to disruption of supersecondary structures, the emergence of phenotypes, as well guiding rational protein engineering. The advent of fast and accurate computational tools has enabled us to comprehensively explore the landscape of mutation effects on protein structures, prioritizing mutations for rational experimental validation.Here we describe the use of two complementary web-based in silico methods, DUET and DynaMut, developed to infer the effects of mutations on folding, stability, and flexibility and how they can be used to explore and interpret these effects on protein supersecondary structures.
Publisher: Oxford University Press (OUP)
Date: 21-03-2022
Abstract: We use deep imaging from the Dark Energy Camera to explore the peripheral regions of nine globular clusters in the outer halo of the Milky Way. Apart from Whiting 1 and NGC 7492, which are projected against the Sagittarius stream, we see no evidence for adjacent stellar populations to indicate any of these clusters is associated with coherent tidal debris from a destroyed host dwarf. We also find no evidence for tidal tails around any of the clusters in our s le however, both NGC 1904 and 6981 appear to possess outer envelopes. Motivated by a slew of recent Gaia-based discoveries, we compile a s le of clusters with robust detections of extra-tidal structure, and search for correlations with orbital properties. While we observe that clusters with tidal tails are typically on moderately or very eccentric orbits that are highly inclined to the Galactic plane and often retrograde, these are neither necessary nor sufficient conditions for the formation of extra-tidal structure. That many objects with tidal tails appear to be accreted leads us to speculate that this lack of consistency may stem from the inhomogeneous dynamical history of the Milky Way globular cluster system. Finally, we note that clusters with prominent stellar envelopes detected in ground-based imaging (such as NGC 1851 and 7089) are now all known from Gaia to possess long tidal tails – experimental confirmation that the presence of an extended envelope is indicative of tidal erosion.
Publisher: American Astronomical Society
Date: 20-11-2018
Publisher: American Astronomical Society
Date: 10-2013
Publisher: Oxford University Press (OUP)
Date: 11-2004
Publisher: American Astronomical Society
Date: 18-01-2007
DOI: 10.1086/511977
Publisher: American Astronomical Society
Date: 30-05-2013
Publisher: Oxford University Press (OUP)
Date: 29-03-2011
Publisher: Wiley
Date: 29-06-2019
DOI: 10.1002/JCLP.22829
Abstract: Explore the mental health trajectories of parents following their child's life-threatening illness/injury. Participants were 217 parents (mean age: 34.9-40.0 66 fathers) of 165 children who presented to a tertiary hospital with a life-threatening illness/injury. Parents completed questionnaires about their mental health and psychosocial stressors within 4 weeks of the child's illness/injury (T1), and 4 months (T2), 7 months (T3), and 19 months (T4) postdiagnosis. For both mothers and fathers, mental health symptoms were elevated at diagnosis declining to normal levels by T3, with a pattern of increase at T4. Fathers demonstrated a faster decline in symptoms between T1 and T2, and fathers, but not mothers, experienced a relapse in depressive symptoms at T4. Fathers reported higher rates of work changes. These findings have important implications for the design and timing of parental interventions to support families of children with life-threatening disease/injury.
Publisher: Oxford University Press (OUP)
Date: 30-06-2023
Abstract: We present results of a search for extremely metal-poor stars in the Large Magellanic Cloud (LMC), which can provide crucial information about the properties of the first stars as well as on the formation conditions prevalent during the earliest stages of star formation in dwarf galaxies. Our search utilized SkyMapper photometry, together with parallax and proper motion cuts (from Gaia), colour–magnitude cuts (by selecting the red giant branch region), and finally a metallicity-sensitive cut. Low-resolution spectra of a s le of photometric candidates were taken using the ANU 2.3m telescope/WiFeS spectrograph, from which seven stars with $\\rm [Fe/H] \\le -2.75$ were identified, two of which have $\\rm [Fe/H] \\le -3$. Radial velocities, derived from the Ca ii triplet lines, closely match the outer rotation curve of the LMC for the majority of the candidates in our s le. Therefore, our targets are robustly members of the LMC based on their 6D phase-space information (coordinates, spectrophotometric distance, proper motions, and radial velocities), and they constitute the most metal-poor stars so far discovered in this galaxy.
Publisher: Oxford University Press (OUP)
Date: 29-11-2016
Publisher: Springer Science and Business Media LLC
Date: 08-07-2015
Publisher: Oxford University Press (OUP)
Date: 16-03-2017
DOI: 10.1093/MNRAS/STX660
Publisher: Oxford University Press (OUP)
Date: 17-01-2023
Abstract: The advent of large-scale stellar spectroscopic surveys naturally leads to the implementation of machine learning techniques to isolate, for ex le, small sub-s les of potentially interesting stars from the full data set. A recent ex le is the application of the t-SNE statistical method to ∼600 000 stellar spectra from the GALAH survey in order to identify a s le of candidate extremely metal-poor (EMP [Fe/H] ≤ –3) stars. We report the outcome of low-resolution spectroscopic follow-up of 83 GALAH EMP candidates that lack any previous metallicity estimates. Overall, the statistical selection is found to be efficient (∼one-third of the candidates have [Fe/H] ≤ –2.75) with low contamination (& per cent have [Fe/H] & –2), and with a metallicity distribution function that is consistent with previous work. Five stars are found to have [Fe/H] ≤ –3.0, one of which is a main sequence turnoff star. Two other stars are revealed as likely carbon-enhanced metal-poor (CEMP) stars of type CEMP-s, and a known carbon star is re-identified. The results indicate that the statistical selection approach employed was successful, and therefore it can be applied to forthcoming even larger stellar spectroscopic surveys with the expectation of similar positive outcomes.
Publisher: Oxford University Press (OUP)
Date: 05-2008
Publisher: Oxford University Press (OUP)
Date: 28-06-2014
Publisher: Oxford University Press (OUP)
Date: 04-07-2016
Publisher: Oxford University Press (OUP)
Date: 02-10-2017
Publisher: American Astronomical Society
Date: 13-11-2017
Publisher: Oxford University Press (OUP)
Date: 02-2017
DOI: 10.1093/MNRAS/STX263
Publisher: Springer Science and Business Media LLC
Date: 09-2009
DOI: 10.1038/NATURE08327
Abstract: In hierarchical cosmological models, galaxies grow in mass through the continual accretion of smaller ones. The tidal disruption of these systems is expected to result in loosely bound stars surrounding the galaxy, at distances that reach 10-100 times the radius of the central disk. The number, luminosity and morphology of the relics of this process provide significant clues to galaxy formation history, but obtaining a comprehensive survey of these components is difficult because of their intrinsic faintness and vast extent. Here we report a panoramic survey of the Andromeda galaxy (M31). We detect stars and coherent structures that are almost certainly remnants of dwarf galaxies destroyed by the tidal field of M31. An improved census of their surviving counterparts implies that three-quarters of M31's satellites brighter than M(v) = -6 await discovery. The brightest companion, Triangulum (M33), is surrounded by a stellar structure that provides persuasive evidence for a recent encounter with M31. This panorama of galaxy structure directly confirms the basic tenets of the hierarchical galaxy formation model and reveals the shared history of M31 and M33 in the unceasing build-up of galaxies.
Publisher: Cambridge University Press (CUP)
Date: 07-2015
DOI: 10.1016/J.EURPSY.2014.12.008
Abstract: Parents of children with life threatening illness or injuries are at elevated risk of distress reactions, involving symptoms of acute stress disorder, depression and anxiety. Currently, the impact of child illness factors is unclear, and to date research systematically examining the prevalence of these psychological reactions across different illness groups with an acute life threat is sparse. This is important to explore given that studies show that parent functioning impacts on the psychological adjustment and recovery of the ill child. At four weeks following a child's diagnosis of a serious illness, 49–54% of parents met DSM-IV criteria for acute stress disorder, across a number of illness groups, whereas 15–27% of parents were in the moderate/severe range for depression and anxiety, and 25–31% for stress. Results from this study demonstrate that rates and severity of these psychological reactions in parents of seriously ill children do not vary according to illness type. A life threatening childhood illness/injury can lead to significant distress reactions in parents, with independent studies finding such reactions in several different illness groups. To date, there is limited research systematically comparing the prevalence of adverse parental psychological reactions across different childhood illness groups with an acute life threat. This study aimed to investigate the frequency and severity of symptoms of acute traumatic stress, depression, anxiety and general stress in parents, following admission of their child to hospital for a life threatening illness. The study also aimed to explore the relationship between these symptoms, and to determine whether they differ according to illness/injury. Cross-sectional data from a prospective, longitudinal study are reported. Participants were 194 parents of 145 children (49 couples), admitted to cardiology ( n = 53), oncology ( n = 40) and pediatric intensive care units ( n = 52), for serious illnesses/injuries. Parents completed self-report questionnaires within four weeks of hospital admission. Rates of acute traumatic stress ( P = 0.262), depression ( P = 0.525), anxiety ( P = 0.453) and general stress symptoms ( P = 0.720) in parents were comparable across illness type, with 49–54% reaching criteria for acute stress disorder, 15–27% having clinical levels of depression and anxiety, and 25–31% for general stress. Anxiety was most strongly associated with acute traumatic stress ( r = 0.56), closely followed by stress ( r = 0.52) and depression ( r = 0.49), with all correlations highly significant ( P 0.001). These findings provide evidence that the child's medical condition is not associated with parents’ experience of clinically significant psychological symptoms, and emphasize the importance for health care providers to be aware of these potential psychological reactions in parents, regardless of the type of illness.
Publisher: Oxford University Press (OUP)
Date: 12-12-2019
Abstract: We present the first SkyMapper stellar population analysis of the Large Magellanic Cloud (hereafter LMC), including the identification of 3578 candidate Carbon Stars through their extremely red g − r colours. Coupled with Gaia astrometry, we analyse the distribution and kinematics of this Carbon Star population, finding the LMC to be centred at (RA, Dec.) = (80.90° ± 0.29, −68.74° ± 0.12), with a bulk proper motion of $(\\mu _{\\alpha },\\mu _{\\delta }) = (1.878\\pm 0.007,0.293\\pm 0.018) \\, \\mathrm{mas \\, yr^{-1}}$ and a disc inclination of i = 25.6° ± 1.1 at position angle θ = 135.6° ± 3.3°. We complement this study with the identification and analysis of additional stellar populations, finding that the dynamical centre for red giant branch stars is similar to that seen for the Carbon Stars, whereas for young stars the dynamical centre is significantly offset from the older populations. This potentially indicates that the young stars were formed as a consequence of a strong tidal interaction, probably with the Small Magellanic Cloud. In terms of internal dynamics, the tangential velocity profile increases linearly within $\\sim \\!3\\ \\, \\mathrm{kpc}$, after which it maintains an approximately constant value of $V_{\\mathrm{ rot}} = 83.6\\pm 1.7 \\, \\mathrm{km \\, s^{-1}}$ until $\\sim \\!7 \\, \\mathrm{kpc}$. With an asymmetric drift correction, we estimate the mass within $7\\, \\mathrm{kpc}$ to be $M_{\\rm LMC}(\\lt 7\\, \\mathrm{kpc}) = (2.5\\pm 0.1)\\times 10^{10}{\\rm \\, {\\rm M}_{\\odot }}$ and within the tidal radius ($\\sim\\! 30\\ \\, \\mathrm{kpc}$) to be $M_{\\rm LMC}(\\lt 30\\, \\mathrm{kpc}) = (1.06 \\pm 0.32)\\times 10^{11}\\ {\\rm \\, {\\rm M}_{\\odot }}$, consistent with other recent measurements.
Publisher: Oxford University Press (OUP)
Date: 12-08-2017
Publisher: EDP Sciences
Date: 2012
Publisher: Oxford University Press (OUP)
Date: 14-07-2020
Abstract: We present an overview of, and first science results from, the Magellanic Edges Survey (MagES), an ongoing spectroscopic survey mapping the kinematics of red clump and red giant branch stars in the highly substructured periphery of the Magellanic Clouds. In conjunction with Gaia astrometry, MagES yields a s le of ~7000 stars with in idual 3D velocities that probes larger galactocentric radii than most previous studies. We outline our target selection, observation strategy, data reduction, and analysis procedures, and present results for two fields in the northern outskirts (& ° on-sky from the centre) of the Large Magellanic Cloud (LMC). One field, located in the vicinity of an arm-like overdensity, displays apparent signatures of perturbation away from an equilibrium disc model. This includes a large radial velocity dispersion in the LMC disc plane, and an asymmetric line-of-sight velocity distribution indicative of motions vertically out of the disc plane for some stars. The second field reveals 3D kinematics consistent with an equilibrium disc, and yields Vcirc = 87.7 ± 8.0 km s−1 at a radial distance of ~10.5 kpc from the LMC centre. This leads to an enclosed mass estimate for the LMC at this radius of (1.8 ± 0.3) × 1010 M⊙.
Publisher: American Astronomical Society
Date: 12-05-2015
Publisher: Oxford University Press (OUP)
Date: 25-10-2019
Publisher: Oxford University Press (OUP)
Date: 14-04-2018
DOI: 10.1093/MNRAS/STY916
Publisher: Oxford University Press (OUP)
Date: 11-08-2003
Publisher: Oxford University Press (OUP)
Date: 02-07-2015
Publisher: Oxford University Press (OUP)
Date: 24-05-2018
Abstract: Serious childhood illness is associated with significant parent psychological distress. This study aimed to (a) document acute and posttraumatic stress symptoms (PTSS) in parents of children with various life-threatening illnesses (b) identify trajectory patterns of parental PTSS and recovery over 18 months (c) determine psychosocial, demographic, and illness factors associated with trajectory group membership. In total, 159 parents (115 mothers, 44 fathers) from 122 families participated in a prospective, longitudinal study that assessed parent psychological responses across four time points-at diagnosis, and 3, 6, and 18 months later. Children were admitted to the Cardiology, Oncology, and Pediatric Intensive Care Departments in a tertiary pediatric hospital. The primary outcome was parent PTSS. Three distinct parent recovery profiles were identified-"Resilient," "Recovery," and "Chronic." The "Resilient" class (33%) showed low distress responses across the trajectory period, whereas the "Recovery" class (52%) showed significantly higher levels of distress at the time of diagnosis that gradually declined over the first months following their child's illness. Both of these classes nevertheless remained within the normative range throughout. In contrast, the "Chronic" class (13%) was consistently high in severity, remaining within the clinical range across the entire period. Psychosocial factors such as mood, anxiety, and emotional responses predicted group membership, whereas demographic and illness factors did not. Parents show considerable resilience in the face of children's life-threatening illnesses. Early assessment of parent psychosocial factors may aid identification of those who would benefit from early intervention.
Publisher: American Astronomical Society
Date: 12-2021
Abstract: Stellar streams are excellent probes of the underlying gravitational potential in which they evolve. In this work, we fit dynamical models to five streams in the Southern Galactic hemisphere, combining observations from the Southern Stellar Stream Spectroscopic Survey ( S 5 ), Gaia EDR3, and the Dark Energy Survey, to measure the mass of the Large Magellanic Cloud (LMC). With an ensemble of streams, we find a mass of the LMC ranging from ∼14–19 × 10 10 M ⊙ , probed over a range of closest approach times and distances. With the most constraining stream (Orphan–Chenab), we measure an LMC mass of 18.8 − 4.0 + 3.5 × 10 10 M ⊙ , probed at a closest approach time of 310 Myr and a closest approach distance of 25.4 kpc. This mass is compatible with previous measurements, showing that a consistent picture is emerging of the LMC’s influence on structures in the Milky Way. Using this s le of streams, we find that the LMC’s effect depends on the relative orientation of the stream and LMC at their point of closest approach. To better understand this, we present a simple model based on the impulse approximation and we show that the LMC’s effect depends both on the magnitude of the velocity kick imparted to the stream and the direction of this kick.
Publisher: American Astronomical Society
Date: 2022
Publisher: American Astronomical Society
Date: 25-10-2019
Publisher: American Astronomical Society
Date: 03-2007
DOI: 10.1086/510879
Publisher: Informa UK Limited
Date: 11-05-2017
DOI: 10.1080/17460441.2017.1322579
Abstract: Mutations introduce ersity into genomes, leading to selective changes and driving evolution. These changes have contributed to the emergence of many of the current major health concerns of the 21st century, from the development of genetic diseases and cancers to the rise and spread of drug resistance. The experimental systematic testing of all mutations in a system of interest is impractical and not cost-effective, which has created interest in the development of computational tools to understand the molecular consequences of mutations to aid and guide rational experimentation. Areas covered: Here, the authors discuss the recent development of computational methods to understand the effects of coding mutations to protein function and interactions, particularly in the context of the 3D structure of the protein. Expert opinion: While significant progress has been made in terms of innovative tools to understand and quantify the different range of effects in which a mutation or a set of mutations can give rise to a phenotype, a great gap still exists when integrating these predictions and drawing causality conclusions linking variants. This often requires a detailed understanding of the system being perturbed. However, as part of the drug development process it can be used preemptively in a similar fashion to pharmacokinetics predictions, to guide development of therapeutics to help guide the design and analysis of clinical trials, patient treatment and public health policy strategies.
Publisher: Oxford University Press (OUP)
Date: 22-07-2019
Abstract: We present new horizontal branch (HB) distance measurements to 17 of the faintest known M31 satellites (−6 ≲ MV ≲ −13) based on deep Hubble Space Telescope (HST) imaging. The colour–magnitude diagrams extend ∼1–2 mag below the HB, which provides for well-defined HBs, even for faint galaxies in which the tip of the red giant branch (TRGB) is sparsely populated. We determine distances across the s le to an average precision of 4 per cent (∼30 kpc at 800 kpc). We find that the majority of these galaxies are in good agreement, though slightly farther (0.1–0.2 mag) when compared to recent ground-based TRGB distances. Two galaxies (And IX and And XVII) have discrepant HST and ground-based distances by ∼0.3 mag (∼150 kpc), which may be due to contamination from Milky Way foreground stars and/or M31 halo stars in sparsely populated TRGB regions. We use the new distances to update the luminosities and structural parameters for these 17 M31 satellites. The new distances do not substantially change the spatial configuration of the M31 satellite system. We comment on future prospects for precise and accurate HB distances for faint galaxies in the Local Group and beyond.
Publisher: Cambridge University Press (CUP)
Date: 12-2007
DOI: 10.1017/S1743921308024332
Abstract: The program of IAU scientific meetings is one of the most important means by which the IAU pursues its goal of promoting astronomy through international collaboration. A large fraction of the Union's budget is devoted to the support of the IAU scientific meetings. The Executive Committee (EC) places great emphasis on maintaining high scientific standards, coverage of a balanced spectrum of topics, and an appropriately international flavor for the programme of IAU Meetings. In that respect, the ICSU rules on non-discrimination in the access of qualified scientists from all parts of the world to any IAU meeting apply.
Publisher: American Astronomical Society
Date: 18-03-2011
Publisher: Oxford University Press (OUP)
Date: 17-09-2010
Publisher: Oxford University Press (OUP)
Date: 18-10-2022
Abstract: We use data from the Magellanic Edges Survey (MagES) in combination with Gaia EDR3 to study the extreme southern outskirts of the Small Magellanic Cloud (SMC), focussing on a field at the eastern end of a long arm-like structure which wraps around the southern periphery of the Large Magellanic Cloud (LMC). Unlike the remainder of this structure, which is thought to be comprised of perturbed LMC disc material, the aggregate properties of the field indicate a clear connection with the SMC. We find evidence for two stellar populations in the field: one having properties consistent with the outskirts of the main SMC body, and the other significantly perturbed. The perturbed population is on average ∼0.2 dex more metal-rich, and is located ∼7 kpc in front of the dominant population with a total space velocity relative to the SMC centre of ∼230 km s−1 broadly in the direction of the LMC. We speculate on possible origins for this perturbed population, the most plausible of which is that it comprises debris from the inner SMC that has been recently tidally stripped by interactions with the LMC.
Publisher: Oxford University Press (OUP)
Date: 12-09-2019
Abstract: We present and discuss the results of a search for extremely metal-poor stars based on photometry from data release DR1.1 of the SkyMapper imaging survey of the southern sky. In particular, we outline our photometric selection procedures and describe the low-resolution (R ≈ 3000) spectroscopic follow-up observations that are used to provide estimates of effective temperature, surface gravity, and metallicity ([Fe/H]) for the candidates. The selection process is very efficient: of the 2618 candidates with low-resolution spectra that have photometric metallicity estimates less than or equal to −2.0, 41 per cent have [Fe/H] ≤ −2.75 and only approximately seven per cent have [Fe/H] −2.0 dex. The most metal-poor candidate in the s le has [Fe/H] −4.75 and is notably carbon rich. Except at the lowest metallicities ([Fe/H] −4), the stars observed spectroscopically are dominated by a ‘carbon-normal’ population with [C/Fe]1D, LTE ≤ +1 dex. Consideration of the A(C)1D, LTE versus [Fe/H]1D, LTE diagram suggests that the current selection process is strongly biased against stars with A(C)1D, LTE 7.3 (predominantly CEMP-s) while any bias against stars with A(C)1D, LTE 7.3 and [C/Fe]1D,LTE +1 (predominantly CEMP-no) is not readily quantifiable given the uncertainty in the SkyMapper v-band DR1.1 photometry. We find that the metallicity distribution function of the observed s le has a power-law slope of Δ(Log N)/Δ[Fe/H] = 1.5 ± 0.1 dex per dex for −4.0 ≤ [Fe/H] ≤ −2.75, but appears to drop abruptly at [Fe/H] ≈ −4.2, in line with previous studies.
Publisher: Oxford University Press (OUP)
Date: 11-2003
Publisher: MDPI AG
Date: 05-05-2023
Abstract: One of the aims of our paper “The Paradox of Suicide Prevention” is to promote greater discourse on suicide prevention, with a particular focus on the mental health models used for the identification of, and interventions with, in iduals who come into contact with tertiary mental health services [...]
Publisher: Elsevier BV
Date: 12-2006
Publisher: Oxford University Press (OUP)
Date: 05-12-2012
DOI: 10.1093/MNRAS/STS387
Publisher: Oxford University Press (OUP)
Date: 11-07-2009
Publisher: Informa UK Limited
Date: 02-07-2016
Publisher: Oxford University Press (OUP)
Date: 29-07-2014
Publisher: EDP Sciences
Date: 11-2011
Publisher: Oxford University Press (OUP)
Date: 15-07-2021
Abstract: We present chemical abundances for 21 elements (from Li to Eu) in 150 metal-poor Galactic stars spanning −4.1 & [Fe/H] & −2.1. The targets were selected from the SkyMapper survey and include 90 objects with [Fe/H] ≤ −3 of which some 15 have [Fe/H] ≤ −3.5. When combining the s le with our previous studies, we find that the metallicity distribution function has a power-law slope of Δ(log N)/Δ[Fe/H] = 1.51 ± 0.01 dex per dex over the range −4 ≤ [Fe/H] ≤ −3. With only seven carbon-enhanced metal-poor stars in the s le, we again find that the selection of metal-poor stars based on SkyMapper filters is biased against highly carbon-rich stars for [Fe/H] & −3.5. Of the 20 objects for which we could measure nitrogen, 11 are nitrogen-enhanced metal-poor (NEMP) stars. Within our s le, the high NEMP fraction (55 per cent ± 21 per cent) is compatible with the upper range of predicted values (between 12 per cent and 35 per cent). The chemical abundance ratios [X/Fe] versus [Fe/H] exhibit similar trends to previous studies of metal-poor stars and Galactic chemical evolution models. We report the discovery of nine new r-I stars, four new r-II stars, one of which is the most metal-poor known, nine low-α stars with [α/Fe] ≤ 0.15 as well as one unusual star with [Zn/Fe] = +1.4 and [Sr/Fe] = +1.2 but with normal [Ba/Fe]. Finally, we combine our s le with literature data to provide the most extensive view of the early chemical enrichment of the Milky Way Galaxy.
Publisher: American Astronomical Society
Date: 07-2021
Publisher: Center for Open Science
Date: 21-10-2021
Abstract: Vaccines are a powerful and relatively safe tool to protect against a range of serious diseases. Nonetheless, a sizeable minority of people express ‘vaccination hesitancy’. Accordingly, understanding the bases of this hesitancy represents a significant public health challenge. In the present study we sought to examine the role of Big Five personality traits and general intelligence as predictors of vaccination hesitancy, across two vaccination types, in a large (N= 9667) s le of UK adults drawn from the Understanding Society longitudinal household study. We found that lower general intelligence was associated with COVID-19 and seasonal flu vaccination hesitancy, and lower neuroticism was associated with COVID-19 vaccination hesitancy. Although the self-reported reasons for being vaccine hesitant indicated a range of factors were important to people, lower general intelligence was associated with virtually all of these reasons. In contrast, Big 5 personality traits showed more nuanced patterns of association. These findings provide important insights into vaccination hesitancy and help to reconcile some of the inconsistencies found in previous literature.
Publisher: Oxford University Press (OUP)
Date: 15-09-2021
Abstract: We present a panoramic survey of the isolated Local Group dwarf irregular galaxy NGC 6822. Our photometry reaches ∼2–3 mag deeper than most previous studies and spans the widest area around the dwarf compared to any prior work. We observe no stellar overdensities in the outskirts of NGC 6822 to V ∼ 30 mag arcsec−2 and a projected radius of 16.5 kpc. This indicates that NGC 6822 has not experienced any recent interaction with a companion galaxy, despite previous suggestions to the contrary. Similarly, we find no evidence for any dwarf satellites of NGC 6822 to a limiting luminosity MV ≈ −5. NGC 6822 contains a disc of H i gas and young stars, oriented at ∼60○ to an extended spheroid composed of old stellar populations. We observe no correlation between the distribution of young stars and spheroid members. Our imaging allows us to trace the spheroid to nearly 11 kpc along its major axis, commensurate with the extent of the NGC 6822 globular cluster system. We find that the spheroid becomes increasingly flattened at larger radii, and its position angle twists by up to 40○. We use Gaia EDR3 astrometry to measure a proper motion for NGC 6822, and then s le its orbital parameter space. While this galaxy has spent the majority of its life in isolation, we find that it likely passed within the virial radius of the Milky Way ∼3–4 Gyr ago. This may explain the apparent flattening and twisting observed in the outskirts of its spheroid.
Publisher: Oxford University Press (OUP)
Date: 21-07-2007
Publisher: Oxford University Press (OUP)
Date: 14-03-2012
Publisher: Oxford University Press (OUP)
Date: 30-04-2201
Abstract: We present a multiple population search in two old Large Magellanic Cloud (LMC) Globular clusters, Hodge 11 and NGC 2210. This work uses data from the Advanced Camera for Surveys and Wide Field Camera 3 on the Hubble Space Telescope from programme GO-14164 in Cycle 23. Both of these clusters exhibit a broadened main sequence with the second population representing (20 ± ∼5) per cent for NGC 2210 and (30 ± ∼5) per cent for Hodge 11. In both clusters, the smaller population is redder than the primary population, suggesting CNO variations. Hodge 11 also displays a bluer second population in the horizontal branch, which is evidence for helium enhancement. However, even though NGC 2210 shows similarities to Hodge 11 in the main sequence, there does not appear to be a second population on NGC 2210’s horizontal branch. This is the first photometric evidence that ancient LMC Globular clusters exhibit multiple stellar populations.
Publisher: American Astronomical Society
Date: 11-05-2037
Publisher: American Astronomical Society
Date: 12-05-2015
Publisher: American Astronomical Society
Date: 16-04-2015
Publisher: American Astronomical Society
Date: 24-09-2020
Publisher: Oxford University Press (OUP)
Date: 08-12-2022
Abstract: We present the results of a spectroscopic survey of the outskirts of four globular – 1261, NGC 4590, NGC 1904, and NGC 1851 – covering targets within 1° from the cluster centres, with 2dF/AAOmega on the Anglo-Australian Telescope (AAT) and FLAMES on the very large telescope (VLT). We extracted chemo-dynamical information for in idual stars, from which we estimated the velocity dispersion profile and the rotation of each cluster. The observations are compared to direct N-body simulations and appropriate limepy/spes models for each cluster to interpret the results. In NGC 1851, the detected internal rotation agrees with existing literature, and NGC 1261 shows some rotation signal beyond the truncation radius, likely coming from the escaped stars. We find that the dispersion profiles for both the observations and the simulations for NGC 1261, NGC 1851, and NGC 1904 do not decrease as the limepy/spes models predict beyond the truncation radius, where the N-body simulations show that escaped stars dominate the dispersion profile of NGC 4590 follows the predictions of the limepy/spes models, though the data do not effectively extend beyond the truncation radius. The increasing/flat dispersion profiles in the outskirts of NGC 1261, NGC 1851, and NGC 1904, are reproduced by the simulations. Hence, the increasing/flat dispersion profiles of the clusters in question can be explained by the tidal interaction with the galaxy without introducing dark matter.
Publisher: Oxford University Press (OUP)
Date: 30-11-2022
Abstract: Based upon a metallicity selection, we identify a significant subpopulation of the inner halo globular clusters in the Andromeda Galaxy, which we name the Dulais Structure. It is distinguished as a co-rotating group of 10–20 globular clusters that appear to be kinematically distinct from, and on average more metal-poor than, the majority of the inner halo population. Intriguingly, the orbital axis of this Dulais Structure is closely aligned with that of the younger accretion event recently identified using a subpopulation of globular clusters in the outer halo of Andromeda, and this is strongly suggestive of a causal relationship between the two. If this connection is confirmed, a natural explanation for the kinematics of the globular clusters in the Dulais Structure is that they trace the accretion of a substantial progenitor (∼1011 M⊙) into the halo of Andromeda during the last few billion years, which may have occurred as part of a larger group infall.
Publisher: Springer Science and Business Media LLC
Date: 2013
DOI: 10.1038/NATURE11717
Abstract: Dwarf satellite galaxies are thought to be the remnants of the population of primordial structures that coalesced to form giant galaxies like the Milky Way. It has previously been suspected that dwarf galaxies may not be isotropically distributed around our Galaxy, because several are correlated with streams of H I emission, and may form coplanar groups. These suspicions are supported by recent analyses. It has been claimed that the apparently planar distribution of satellites is not predicted within standard cosmology, and cannot simply represent a memory of past coherent accretion. However, other studies dispute this conclusion. Here we report the existence of a planar subgroup of satellites in the Andromeda galaxy (M 31), comprising about half of the population. The structure is at least 400 kiloparsecs in diameter, but also extremely thin, with a perpendicular scatter of less than 14.1 kiloparsecs. Radial velocity measurements reveal that the satellites in this structure have the same sense of rotation about their host. This shows conclusively that substantial numbers of dwarf satellite galaxies share the same dynamical orbital properties and direction of angular momentum. Intriguingly, the plane we identify is approximately aligned with the pole of the Milky Way's disk and with the vector between the Milky Way and Andromeda.
Publisher: Springer Science and Business Media LLC
Date: 19-08-2010
Abstract: The transition to adolescence is a time of increased vulnerability for risk taking and poor health, social and academic outcomes. Parents have an important role in protecting their children from these potential harms. While the effectiveness of parenting programs in reducing problem behavior has been demonstrated, it is not known if parenting programs that target families prior to the onset of significant behavioral difficulties in early adolescence (9-14 years) improve the wellbeing of adolescents and their parents. This paper describes the rationale and methodology of a randomised controlled trial testing the efficacy of a parenting program for the promotion of factors known to be associated with positive adolescent outcomes, such as positive parenting practices, parent-adolescent relationships and adolescent behavior. One hundred and eighty parents were randomly allocated to an intervention or wait list control group. Parents in the intervention group participated in the ABCD Parenting Young Adolescents Program, a 6-session behavioral family intervention program which also incorporates acceptance-based strategies. Participants in the Wait List control group did not receive the intervention during a six month waiting period. The study was designed to comply with recommendations of the CONSORT statement. The primary outcome measures were reduction in parent-adolescent conflict and improvements in parent-adolescent relationships. Secondary outcomes included improvements in parent psychosocial wellbeing, parenting self-efficacy and perceived effectiveness, parent-adolescent communication and adolescent behavior. Despite the effectiveness of parenting programs in reducing child behavioral difficulties, very few parenting programs for preventing problems in adolescents have been described in the peer reviewed literature. This study will provide data which can be used to examine the efficacy of a universal parenting interventions for the promotion of protective factors associated with adolescent wellbeing and will add to the literature regarding the relationships between parent, parenting and adolescent factors. Australian New Zealand Clinical Trials Registry ACTRN12609000194268.
Publisher: American Astronomical Society
Date: 30-03-2021
Abstract: We present a direct comparison of the Pan-Andromeda Archaeological Survey (PAndAS) observations of the stellar halo of M31 with the stellar halos of six galaxies from the Auriga simulations. We process the simulated halos through the A uriga 2PA nd AS pipeline and create PAndAS-like mocks that fold in all observational limitations of the survey data (foreground contamination from the Milky Way stars, incompleteness of the stellar catalogs, photometric uncertainties, etc.). This allows us to study the survey data and the mocks in the same way and generate directly comparable density maps and radial density profiles. We show that the simulations are overall compatible with the observations. Nevertheless, some systematic differences exist, such as a preponderance for metal-rich stars in the mocks. While these differences could suggest that M31 had a different accretion history or has a different mass compared with the simulated systems, it is more likely a consequence of an underquenching of the star formation history of galaxies, related to the resolution of the A uriga simulations. The direct comparison enabled by our approach offers avenues to improve our understanding of galaxy formation as they can help pinpoint the observable differences between observations and simulations. Ideally, this approach will be further developed through an application to other stellar halo simulations. To facilitate this step, we release the pipeline to generate the mocks, along with the six mocks presented and used in this contribution.
Publisher: Informa UK Limited
Date: 06-2020
DOI: 10.1111/AP.12405
Publisher: Oxford University Press (OUP)
Date: 22-04-2016
Publisher: Oxford University Press (OUP)
Date: 18-07-2018
Publisher: American Astronomical Society
Date: 25-06-2009
Publisher: Oxford University Press (OUP)
Date: 07-2007
Publisher: Oxford University Press (OUP)
Date: 18-06-2014
DOI: 10.1093/MNRAS/STU771
Publisher: Oxford University Press (OUP)
Date: 17-07-2019
Abstract: We report the discovery of SMSS J160540.18−144323.1, a new ultra metal-poor halo star discovered with the SkyMapper telescope. We measure $\\left[\\rm {Fe}/\\rm {H}\\right]= -6.2 \\pm 0.2$ (1D LTE), the lowest ever detected abundance of iron in a star. The star is strongly carbon-enhanced, $\\left[\\rm {C}/\\rm {Fe}\\right] = 3.9 \\pm 0.2$, while other abundances are compatible with an α-enhanced solar-like pattern with $\\left[\\rm {Ca}/\\rm {Fe}\\right] = 0.4 \\pm 0.2$, $\\left[\\rm {Mg}/\\rm {Fe}\\right] = 0.6 \\pm 0.2$, $\\left[\\rm {Ti}/\\rm {Fe}\\right] = 0.8 \\pm 0.2$, and no significant s- or r-process enrichment, $\\left[\\rm {Sr}/\\rm {Fe}\\right] \\lt 0.2$ and $\\left[\\rm {Ba}/\\rm {Fe}\\right] \\lt 1.0$ (3σ limits). Population III stars exploding as fallback supernovae may explain both the strong carbon enhancement and the apparent lack of enhancement of odd-Z and neutron-capture element abundances. Grids of supernova models computed for metal-free progenitor stars yield good matches for stars of about $10\\, \\rm M_\\odot$ imparting a low kinetic energy on the supernova ejecta, while models for stars more massive than roughly $20\\, \\rm M_\\odot$ are incompatible with the observed abundance pattern.
Publisher: American Medical Association (AMA)
Date: 31-07-2020
Publisher: Oxford University Press (OUP)
Date: 05-12-2023
Abstract: We present detailed C, O, Na, Mg, Si, Ca, Ti, V, Fe, Zr, Ba, and Eu abundance measurements for 20 red giant branch (RGB) stars in the Large Magellanic Cloud (LMC) star cluster NGC 1846 ([Fe/H] = −0.59). This cluster is 1.95 Gyr old and lies just below the supposed lower age limit (2 Gyr) for the presence of multiple populations in massive star clusters. Our measurements are based on high- and low-resolution VLT/FLAMES spectra combined with photometric data from Hubble Space Telescope (HST). Corrections for non-local thermodynamic equilibrium effects are also included for O, Na, Mg, Si, Ca, Fe, and Ba. Our results show that there is no evidence for multiple populations in this cluster based on the lack of any intrinsic star-to-star spread in the abundances of Na and O: We place 95 per cent confidence limits on the intrinsic dispersion for these elements of ≤0.07 and ≤0.09 dex, respectively. However, we do detect a significant spread in the carbon abundances, indicating varying evolutionary mixing occurring on the RGB that increases with luminosity. Overall, the general abundance patterns for NGC 1846 are similar to those seen in previous studies of intermediate-age LMC star clusters and field stars.
Publisher: Oxford University Press (OUP)
Date: 2003
Publisher: IOP Publishing
Date: 16-07-2008
Publisher: Springer Science and Business Media LLC
Date: 29-07-2020
Publisher: Oxford University Press (OUP)
Date: 09-2002
Publisher: Research Square Platform LLC
Date: 28-10-2021
DOI: 10.21203/RS.3.RS-1025965/V1
Abstract: The Fermi Bubbles are giant, γ-ray emitting lobes emanating from the nucleus of the Milky Way [1, 2] discovered in ∼1-100 GeV data collected by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope [3]. Previous work [4] has revealed substructure within the Fermi Bubbles that has been interpreted as a signature of collimated outflows from the Galaxy’s super-massive black hole. Here we show that much of the γ-ray emission associated to the brightest region of substructure – the so-called cocoon – is actually due to the Sagittarius dwarf spheroidal (Sgr dSph) galaxy. This large Milky Way satellite is viewed through the Fermi Bubbles from the position of the Solar System. As a tidally and ram-pressure stripped remnant, the Sgr dSph has no on-going star formation, but we demonstrate that its γ-ray signal is naturally explained by inverse Compton scattering of cosmic microwave back-ground photons by high-energy electron-positron pairs injected by the dwarf’s millisecond pulsar (MSP) population, combined with these objects’ magnetospheric emission. This finding suggests that MSPs likely produce significant γ-ray emission amongst old stellar populations, potentially confounding indirect dark matter searches in regions such as the Galactic Centre, the Andromeda galaxy, and other massive Milky Way dwarf spheroidals.
Publisher: Oxford University Press (OUP)
Date: 06-06-2007
Publisher: Oxford University Press (OUP)
Date: 23-12-2019
Abstract: We present a detailed study of stellar rotation in the massive 1.5 Gyr old cluster NGC 1846 in the Large Magellanic Cloud. Similar to other clusters at this age, NGC 1846 shows an extended main-sequence turn-off (eMSTO), and previous photometric studies have suggested it could be bimodal. In this study, we use MUSE integral-field spectroscopy to measure the projected rotational velocities (vsin i) of around $1400$ stars across the eMSTO and along the upper main sequence of NGC 1846. We measure vsin i values up to $\\sim 250\\, {\\rm km\\, s^{-1}}$ and find a clear relation between the vsin i of a star and its location across the eMSTO. Closer inspection of the distribution of rotation rates reveals evidence for a bimodal distribution, with the fast rotators centred around $v\\sin i=140\\, {\\rm km\\, s^{-1}}$ and the slow rotators centred around $v\\sin i=60\\, {\\rm km\\, s^{-1}}$. We further observe a lack of fast rotating stars along the photometric binary sequence of NGC 1846, confirming results from the field that suggest that tidal interactions in binary systems can spin-down stars. However, we do not detect a significant difference in the binary fractions of the fast and slowly rotating sub-populations. Finally, we report on the serendipitous discovery of a planetary nebula associated with NGC 1846.
Publisher: American Astronomical Society
Date: 14-12-2013
Publisher: Springer Science and Business Media LLC
Date: 03-06-2020
Publisher: Oxford University Press (OUP)
Date: 11-07-2016
Publisher: Springer Science and Business Media LLC
Date: 18-03-2017
Publisher: Cambridge University Press (CUP)
Date: 27-06-2013
DOI: 10.1017/S1047951113000760
Abstract: Objective: The aim of this study was to explore the acute psychosocial risk in families with infants undergoing surgery for a congenital heart disease and, secondarily, to explore the psychosocial impact of antenatal versus post-natal diagnoses. Method: The study s le comprised 39 caregivers (28 mothers) of 29 children diagnosed with a congenital heart disease and requiring surgery within the first 4 weeks of life. Psychosocial risk was measured using the Psychosocial Assessment Tool, which was adapted to include four novel items examining infant risk factors, namely, sleeping, feeding, crying, and bonding difficulties. Parents’ psychosocial risk was measured within 4 weeks after their child's surgery and stratified into a three-tiered framework: Universal, Targeted, and Clinical risk. Results: Of the total s le, 61.5% of parents were classified as Universal, that is, at lowest risk 35.9% as Targeted, and 2.6% as Clinical. The within-family parent total Psychosocial Assessment Tool score correlations were non-significant, and there were no differences between families of infants who received post-natal versus antenatal diagnosis or single ventricle versus biventricular repair. Linear regression found that a higher parent education significantly predicted a lower total Psychosocial Assessment Tool score. Conclusions: Findings indicate that, although the majority of parents adapt to the acute stress of surgery for a serious cardiac illness in their infant, the remaining 38.5% report an increased psychosocial risk associated with higher rates of emotional distress, which may impact on the parental quality of life and capacity for optimal parenting. The distribution of psychosocial risk in parents of children undergoing surgery for a congenital heart disease is consistent with that described for parents of children with other serious paediatric diagnoses.
Publisher: Oxford University Press (OUP)
Date: 07-04-2016
Publisher: Oxford University Press (OUP)
Date: 16-09-2013
Publisher: American Astronomical Society
Date: 17-12-2013
Publisher: MDPI AG
Date: 15-11-2022
Abstract: The recognition that we cannot use risk stratification (high, medium, low) to predict suicide or to allocate resources has led to a paradigm shift in suicide prevention efforts. There are challenges in adapting to these new paradigms, including reluctance of clinicians and services to move away from traditional risk categorisations and conversely, the risk of a pendulum swing in which the focus of care swings from one approach to determining service priority and focus (e.g., diagnosis, formulation, risk and clinical care) to a new focus (e.g., suicide specific and non-clinical care), potentially supplanting the previous approach. This paper argues that the Prevention Paradox provides a useful mental model to support a shift in paradigm, whilst maintaining a balanced approach that incorporates new paradigms within the effective aspects of existing ones. The Prevention Paradox highlights the seemingly paradoxical situation where the greatest burden of disease or death is caused by those at low to moderate risk due their larger numbers. Current planning frameworks and resources do not support successful or sustainable adoption of these new approaches, leading to missed opportunities to prevent suicidal behaviours in healthcare. Adopting systems approaches to suicide prevention, such as the Zero Suicide Framework, implemented in a large mental health service in Australia and presented in this paper as a case study, can support a balanced approach of population- and in idual-based suicide prevention efforts. Results demonstrate significant reductions in re-presentations with suicide attempts for consumers receiving this model of care however, the increasing numbers of placements compromise the capacity of clinical teams to complete all components of standardised pathway of care. This highlights the need for review of resource planning frameworks and ongoing evaluations of the critical aspects of the interventions.
Publisher: Springer Science and Business Media LLC
Date: 07-07-2021
DOI: 10.1038/S41586-021-03611-2
Abstract: Neutron-star mergers were recently confirmed as sites of rapid-neutron-capture (r-process) nucleosynthesis
Publisher: Springer Science and Business Media LLC
Date: 09-09-2022
DOI: 10.1007/S10578-022-01428-2
Abstract: The study aimed to provide further evidence for the validity of the 33-item Adolescent Functioning Scale (AFS) as a parent- and adolescent-report scale of adolescent adjustment. In separate s les of parents ( N = 542 88% female) and adolescents ( N = 303 60% female), confirmatory factor analyses supported the original 4-factor structure of the AFS. Analyses produced a 28-item parent measure, and a 27-item adolescent measure. Parent and adolescent versions included positive development, oppositional behaviour, antisocial behaviour and emotional problems subscales. Evidence for convergent and construct validity was provided through correlations with existing measures of adolescent functioning and parenting. The AFS demonstrated configural and metric invariance, but not scalar variance. The study provided support for the validity and reliability of the revised AFS for parents and adolescents. The strong psychometric properties, and brief and multi-dimensional nature of the AFS means that it will have utility in research and applied contexts.
Publisher: Wiley
Date: 07-02-2021
DOI: 10.1002/CL2.1146
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.EJON.2016.08.008
Abstract: Child emotional and behavioral problems constitute significant sequelae of acute lymphoblastic leukemia (ALL) treatment. The aims of this study were to a) examine the feasibility, acceptability and satisfaction of a parenting intervention amongst parents of children with ALL and b) explore whether participation in a parenting intervention shows promise for improvements in child behavior. 12 parents with a child aged between 2 and 8 years receiving maintenance phase treatment for ALL participated in a phase 2 randomized controlled trial comparing eight weeks of group online participation in Triple P: Positive Parenting Program with no intervention. The number of eligible parents who completed the intervention was low (31.6%). Main reasons for non-consent or dropout were program time commitment too high or content not relevant. For parents who completed the intervention, satisfaction and acceptability was high. Parents reported the intervention as highly relevant and topical, feasible, helpful and a positive experience. Results indicated a non-significant trend towards improved total child behavioral and emotional difficulties following the intervention. Qualitative results indicated that intervention group parents reported improvements in parenting skills and competence, and decreased child behavioral problems. These pilot data highlight the difficulties of engaging and retaining parents in an 8-week parenting intervention in this context. For parents who completed the intervention, results indicated high feasibility, acceptability and satisfaction. Suggestions for further research and intervention modifications are provided to enhance uptake and strengthen efforts to assist parents in addressing child behavioral and emotional challenges during ALL treatment.
Publisher: Oxford University Press (OUP)
Date: 15-03-2016
DOI: 10.1093/MNRAS/STW608
Publisher: Oxford University Press (OUP)
Date: 25-11-2021
Abstract: The highly-substructured outskirts of the Magellanic Clouds provide ideal locations for studying the complex interaction history between both Clouds and the Milky Way (MW). In this paper, we investigate the origin of a & ° long arm-like feature in the northern outskirts of the Large Magellanic Cloud (LMC) using data from the Magellanic Edges Survey (MagES) and Gaia EDR3. We find that the arm has a similar geometry and metallicity to the nearby outer LMC disc, indicating that it is comprised of perturbed disc material. Whilst the azimuthal velocity and velocity dispersions along the arm are consistent with those in the outer LMC, the in-plane radial velocity and out-of-plane vertical velocity are significantly perturbed from equilibrium disc kinematics. We compare these observations to a new suite of dynamical models of the Magellanic/MW system, which describe the LMC as a collection of tracer particles within a rigid potential, and the SMC as a rigid Hernquist potential. Our models indicate the tidal force of the MW during the LMC’s infall is likely responsible for the observed increasing out-of-plane velocity along the arm. Our models also suggest close LMC/SMC interactions within the past Gyr, particularly the SMC’s pericentric passage ∼150 Myr ago and a possible SMC crossing of the LMC disc plane ∼400 Myr ago, likely do not perturb stars that today comprise the arm. Historical interactions with the SMC prior to ∼1 Gyr ago may be required to explain some of the observed kinematic properties of the arm, in particular its strongly negative in-plane radial velocity.
Publisher: Oxford University Press (OUP)
Date: 05-07-2018
Publisher: Oxford University Press (OUP)
Date: 22-04-2016
DOI: 10.1093/MNRAS/STW966
Publisher: American Astronomical Society
Date: 30-12-2009
Publisher: American Psychological Association (APA)
Date: 05-2021
DOI: 10.1037/PAS0000992
Publisher: Springer Netherlands
Date: 2008
Publisher: Informa UK Limited
Date: 29-03-2022
Publisher: Springer International Publishing
Date: 2016
Publisher: Oxford University Press (OUP)
Date: 06-07-2017
Publisher: Oxford University Press (OUP)
Date: 07-2009
Publisher: Oxford University Press (OUP)
Date: 14-03-2016
DOI: 10.1093/MNRAS/STW497
Publisher: Oxford University Press (OUP)
Date: 28-06-2014
Publisher: Oxford University Press (OUP)
Date: 21-06-2005
Publisher: Oxford University Press (OUP)
Date: 28-08-2014
Publisher: Springer International Publishing
Date: 14-11-2014
Publisher: Springer Science and Business Media LLC
Date: 12-2013
Publisher: Cambridge University Press (CUP)
Date: 07-2008
DOI: 10.1017/S1743921308028627
Abstract: The recent discovery of multiple stellar populations in massive Galactic globular clusters poses a serious challenge for models of star cluster formation and evolution. A new angle on this problem is being provided by rich intermediate-age clusters in the Magellanic Clouds. In this contribution we describe the discovery of three such LMC clusters with peculiar main-sequence turn-off morphologies. The simplest interpretation of our observations is that each of these three clusters is comprised of two or more stellar populations spanning an age interval of ~300 Myr. Surprisingly, such features may not be unusual in this type of cluster.
Publisher: Oxford University Press (OUP)
Date: 2010
Publisher: American Astronomical Society
Date: 28-10-2021
Publisher: Oxford University Press (OUP)
Date: 28-10-2022
Abstract: It has recently been shown that the Large Magellanic Cloud (LMC) has a substantial effect on the Milky Way’s stellar halo and stellar streams. Here, we explore how deformations of the Milky Way and LMC’s dark matter haloes affect stellar streams, and whether these effects are observable. In particular, we focus on the Orphan–Chenab (OC) stream which passes particularly close to the LMC and spans a large portion of the Milky Way’s halo. We represent the Milky Way–LMC system using basis function expansions that capture their evolution in an N-body simulation. We present the properties of this system, such as the evolution of the densities and force fields of each galaxy. The OC stream is evolved in this time-dependent, deforming potential, and we investigate the effects of the various moments of the Milky Way and the LMC. We find that the simulated OC stream is strongly influenced by the deformations of both the Milky Way and the LMC and that this effect is much larger than current observational errors. In particular, the Milky Way dipole has the biggest impact on the stream, followed by the evolution of the LMC’s monopole, and the LMC’s quadrupole. Detecting these effects would confirm a key prediction of collisionless, cold dark matter, and would be a powerful test of alternative dark matter and alternative gravity models.
Publisher: BMJ
Date: 10-2019
DOI: 10.1136/BMJOPEN-2019-031527
Abstract: To establish the prevalence and associations of systemic antibiotic prescription for impetigo by early-career general practitioners (GPs) (GP registrars in their first 18 months in general practice). A cross-sectional analysis of data from the Registrar Clinical Encounters in Training (ReCEnT) study. ReCEnT is an ongoing multisite cohort study of Australian registrars’ in-consultation clinical practice across five Australian states. Registrars participating in ReCEnT from 2010 to 2017. Management of impetigo with systemic antibiotics. 1741 registrars (response rate 96%) provided data from 384 731 problems identified in 246 434 consultations. Impetigo, on first presentation or follow-up, was managed in 930 (0.38%, 95% CI 0.35 to 0.40) consultations and comprised 0.24% (95% CI 0.23 to 0.26) of problems. 683 patients presented with a new diagnosis of impetigo of which 38/683 (5.6%) were not prescribed antibiotics 239/683 (35.0%) were prescribed solely topical antibiotics 306/683 (44.8%) solely systemic antibiotics and 100/683 (14.6%) both systemic and topical antibiotics. The most common systemic antibiotic prescribed was cephalexin (53.5%). Variables independently associated with prescription of systemic antibiotics were an inner regional (compared with major city) location (OR 1.82, 95% CI 1.06 to 3.13 p=0.028), seeking in-consultation information or advice (OR 2.17, 95% CI 1.47 to 3.23 p .001) and ordering pathology (OR 2.13, 95% CI 1.37 to 3.33 p=0.01). Australian early-career GPs prescribe systemic antibiotics (the majority broad-spectrum) for a high proportion of initial impetigo presentations. Impetigo guidelines should clearly specify criteria for systemic antibiotic prescription and in idual antibiotic choice. The role of non-antibiotic management and topical antiseptics needs to be explored further.
Publisher: Oxford University Press (OUP)
Date: 21-06-2022
Abstract: Using spectra obtained with the VLT/FORS2 and Gemini-S/GMOS-S instruments, we have investigated carbon, nitrogen, and sodium abundances in a s le of red giant members of the Small Magellanic Cloud star cluster Kron 3. The metallicity and luminosity of the cluster are comparable to those of Galactic globular clusters but it is notably younger (age ≈ 6.5 Gyr). We have measured the strengths of the CN and CH molecular bands, finding a bimodal CN band-strength distribution and a CH/CN anticorrelation. Application of spectrum synthesis techniques reveals that the difference in the mean [N/Fe] and [C/Fe] values for the CN-strong and CN-weak stars are Δ & [N/Fe]& = 0.63 ± 0.16 dex and Δ & [C/Fe]& = −0.01 ± 0.07 dex after applying corrections for evolutionary mixing. We have also measured sodium abundances from the Na D lines finding an observed range in [Na/Fe] of ∼0.6 dex that correlates positively with the [N/Fe] values and a Δ & [Na/Fe]& = 0.12 ± 0.12 dex. While the statistical significance of the sodium abundance difference is not high, the observed correlation between the Na and N abundances supports its existence. The outcome represents the first star-by-star demonstration of correlated abundance variations involving sodium in an intermediate-age star cluster. The results add to existing photometric and spectroscopic indications of the presence of multiple populations in intermediate-age clusters with masses in excess of ∼105 M⊙. It confirms that the mechanism(s) responsible for the multiple populations in ancient globular clusters cannot solely be an early cosmological effect applying only in old clusters.
Publisher: Oxford University Press (OUP)
Date: 12-09-2018
Publisher: Oxford University Press (OUP)
Date: 12-2004
Publisher: American Astronomical Society
Date: 11-2021
Publisher: Oxford University Press (OUP)
Date: 07-2004
Publisher: American Astronomical Society
Date: 11-05-2018
Publisher: SAGE Publications
Date: 25-04-2018
Abstract: This study explored the relationship between in idual and family-level risk in predicting longer-term parental distress following their child’s unexpected diagnosis of serious illness. A mediation model was tested, whereby parents’ pre-existing psychosocial risk predicts longer-term posttraumatic stress symptoms, indirectly through parents’ acute stress response. One hundred and thirty-two parents of 104 children participated. Acute stress response partially mediated the relationship between psychosocial risk and posttraumatic stress symptoms, with a moderate indirect effect ( r 2 = .20, P M = .56, p .001). Findings demonstrated that cumulative psychosocial risk factors predispose parents to acute stress and longer-term posttraumatic stress symptoms, highlighting the need for psychosocial screening in this population.
Publisher: Oxford University Press (OUP)
Date: 03-12-2013
Publisher: Wiley
Date: 06-06-2012
DOI: 10.1016/J.ADOLESCENCE.2012.05.002
Abstract: This study examined the efficacy of a program for parents of young adolescents combining behavioral family intervention with acceptance‐based strategies. 180 parents were randomly allocated to a 6‐session group ABCD Parenting Young Adolescent Program or wait‐list condition. Completer analysis indicated parents in the intervention reported significantly higher adolescent prosocial behaviors ( p = 0.020), lower conduct problems ( p = 0.048) and total difficulties ( p = 0.041). These parents also reported lower stress associated with adolescent moodiness ( p = 0.032), parent life‐restriction ( p 0.001), adult‐relations ( p 0.001), social isolation ( p = 0.012), incompetence/guilt ( p 0.001), lower stress in the parenting domain ( p 0.001) and lower overall stress ( p = 0.003) relative to the control condition following the intervention period. No other statistically significant differences were evident ( p 0.05). Results of intention‐to‐treat analyses were similar. Greater reliable clinically significant change was also achieved for the intervention condition. Participants reported high satisfaction with all elements of the ABCD program. Results suggest the program may assist parents of young adolescents to promote or maintain protective factors in their families. Australian and New Zealand Clinical Trials Registry: ANZCTRN12609000194268.
Publisher: Cambridge University Press (CUP)
Date: 09-2007
DOI: 10.1017/S1743921308015548
Abstract: Massive star clusters in the Magellanic Clouds are observed to follow a striking trend in size with age – older clusters exhibit a much greater spread in core radius than do younger clusters, which are generally compact. We present results from realistic N -body modelling of massive star clusters, aimed at investigating a dynamical origin for the radius-age trend. We find that stellar-mass black holes, formed as remnants of the most massive stars in a cluster, can constitute a dynamically important population. If retained, these objects rapidly form a dense core where interactions are common, resulting in the scattering of black holes into the cluster halo, and the ejection of black holes from the cluster. These processes heat the stellar component, resulting in prolonged core expansion of a magnitude matching the observations. Core expansion at early times does not result from the action of black holes, but can be reproduced by the effects of rapid mass-loss due to stellar evolution in a primordially mass segregated cluster.
Publisher: Oxford University Press (OUP)
Date: 24-06-2016
Abstract: To examine the validity of the Psychosocial Assessment Tool (PAT) with families of infants (<2 years) and children admitted to hospital with acute life-threatening illnesses. A total of 235 parents of 177 children admitted to oncology, cardiology, or pediatric intensive care completed the PAT and measures of acute stress, trait anxiety, family functioning, and quality of life, a mean 3.7 weeks following diagnosis. A modified PAT was used for families of infants, rendering two forms, PAT (<2) and PAT (2+). Psychometrics for PAT (<2) and PAT (2+) were acceptable. PAT Total and Subscale scores for each version were significantly correlated with validation measures. Internal consistency for PAT subscales was variable. Receiver Operating Characteristics provided some support for PAT cutoffs. PAT scores across illness groups were comparable. This study provides promising support for the PAT as a psychosocial screener for families of infants and older children across illness conditions.
Publisher: Springer Science and Business Media LLC
Date: 19-09-2015
Publisher: Oxford University Press (OUP)
Date: 12-09-2019
Abstract: We present a kinematic and spectroscopic analysis of 38 red giant branch stars, in seven fields, spanning the dwarf spheroidal galaxy Andromeda XXVII and the upper segment of the North West Stream. Both features are located in the outer halo of the Andromeda galaxy at a projected radius of 50–80 kpc, with the stream extending for ∼3° on the sky. Our data are obtained as part of the PAndAS survey and enables us to confirm that Andromeda XXVII’s heliocentric distance is 827 ± 47 kpc and spectroscopic metallicity is $-2.1^{+0.4}_{-0.5}$. We also re-derive Andromeda XXVII’s kinematic properties, measuring a systemic velocity = $-526.1^{+10.0}_{-11.0}$ km s−1 and a velocity dispersion that we find to be non-Gaussian but for which we derive a formal value of 27.0$^{+2.2}_{-3.9}$ km s−1. In the upper segment of the North West Stream we measure mean values for the metallicity = −1.8 ± 0.4, systemic velocity = −519.4 ± 4.0 km s−1, and velocity dispersion = 10.0 ± 4.0 km s−1. We also detect a velocity gradient of 1.7 ± 0.3 km s−1 kpc−1 on an infall trajectory towards M31. With a similar gradient, acting in the same direction, in the lower segment we suggest that the North West Stream is not a single structure. As the properties of the upper segment of the North West Stream and Andromeda XXVII are consistent within 90 per cent confidence limits, it is likely that the two are related and plausible that Andromeda XXVII is the progenitor of this stream.
Publisher: American Astronomical Society
Date: 26-12-2012
Publisher: Oxford University Press (OUP)
Date: 07-03-2019
DOI: 10.1093/MNRAS/STZ645
Abstract: We present results from the analysis of high-resolution spectra obtained with the Keck HIRES spectrograph for a s le of 17 candidate extremely metal-poor (EMP) stars originally selected from commissioning data obtained with the SkyMapper telescope. Fourteen of the stars have not been observed previously at high dispersion. Three have [Fe/H] ≤ −3.0, while the remainder, with two more metal-rich exceptions, have −3.0 ≤ [Fe/H] ≤ −2.0 dex. Apart from Fe, we also derive abundances for the elements C, N, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, and Zn, and for n-capture elements Sr, Ba, and Eu. None of the current s le of stars is found to be carbon-rich. In general, our chemical abundances follow previous trends found in the literature, although we note that two of the most metal-poor stars show very low [Ba/Fe] (∼−1.7) coupled with low [Sr/Ba] (∼−0.3). Such stars are relatively rare in the Galactic halo. One further star, and possibly two others, meet the criteria for classification as a r-I star. This study, together with that of Jacobson et al. (2015), completes the outcomes of the SkyMapper commissioning data survey for EMP stars.
Publisher: Oxford University Press (OUP)
Date: 28-11-2012
DOI: 10.1093/MNRAS/STS336
Publisher: Springer Science and Business Media LLC
Date: 02-10-2019
DOI: 10.1038/S41586-019-1597-1
Abstract: Large galaxies grow through the accumulation of dwarf galaxies
Publisher: Oxford University Press (OUP)
Date: 02-2008
Publisher: Oxford University Press (OUP)
Date: 21-03-2003
Publisher: Oxford University Press (OUP)
Date: 2003
Publisher: American Astronomical Society
Date: 04-2021
Abstract: We present the first spectroscopic measurements of the ATLAS and Aliqa Uma streams from the Southern Stellar Stream Spectroscopic Survey ( S 5 ), in combination with the photometric data from the Dark Energy Survey and astrometric data from Gaia. From the coherence of spectroscopic members in radial velocity and proper motion, we find that these two systems are extremely likely to be one stream with discontinuity in morphology and density on the sky (the “kink” feature). We refer to this entire stream as the ATLAS-Aliqa Uma stream, or the AAU stream. We perform a comprehensive exploration of the effect of baryonic substructures and find that only an encounter with the Sagittarius dwarf ∼0.5 Gyr ago can create a feature similar to the observed “kink.” In addition, we also identify two gaps in the ATLAS component associated with the broadening in the stream width (the “broadening” feature). These gaps have likely been created by small mass perturbers, such as dark matter halos, as the AAU stream is the most distant cold stream known with severe variations in both the stream surface density and the stream track on the sky. With the stream track, stream distance, and kinematic information, we determine the orbit of the AAU stream and find that it has been affected by the Large Magellanic Cloud, resulting in a misalignment between the proper motion and stream track. Together with the Orphan-Chenab Stream, AAU is the second stream pair that has been found to be a single stream separated into two segments by external perturbation.
Publisher: American Astronomical Society
Date: 13-12-2011
Publisher: Oxford University Press (OUP)
Date: 16-09-2019
Abstract: We present a photometric and spectroscopic study of the Milky Way satellite Laevens 3. Using MegaCam/Canada–France–Hawaii Telescope $g$ and $i$ photometry and Keck II/DEIMOS multi-object spectroscopy, we refine the structural and stellar properties of the system. The Laevens 3 colour–magnitude diagram shows that it is quite metal-poor, old ($13.0 \\pm 1.0$ Gyr), and at a distance of $61.4 \\pm 1.0$ kpc, partly based on two RR Lyrae stars. The system is faint ($M_V = -2.8^{+0.2}_{-0.3}$ mag) and compact ($r_h = 11.4 \\pm 1.0$ pc). From the spectroscopy, we constrain the systemic metallicity (${\\rm [Fe/H]}_\\mathrm{spectro} = -1.8 \\pm 0.1$ dex) but the metallicity and velocity dispersions are both unresolved. Using Gaia DR2, we infer a mean proper motion of $(\\mu _\\alpha ^*,\\mu _\\delta)=(0.51 \\pm 0.28,-0.83 \\pm 0.27)$ mas yr−1, which, combined with the system’s radial velocity ($\\langle v_r\\rangle = -70.2 \\pm 0.5 {\\rm \\, km \\,\\, s^{-1}}$), translates into a halo orbit with a pericenter and apocenter of $40.7 ^{+5.6}_{-14.7}$ and $85.6^{+17.2}_{-5.9}$ kpc, respectively. Overall, Laevens 3 shares the typical properties of the Milky Way’s outer halo globular clusters. Furthermore, we find that this system shows signs of mass segregation that strengthens our conclusion that Laevens 3 is a globular cluster.
Publisher: American Psychological Association (APA)
Date: 03-2014
DOI: 10.1037/FSH0000012
Publisher: Springer-Verlag
Date: 2003
DOI: 10.1007/10857603_34
Publisher: Oxford University Press (OUP)
Date: 04-02-2022
Abstract: We report the discovery of J0624–6948, a low-surface brightness radio ring, lying between the Galactic Plane and the large magellanic cloud (LMC). It was first detected at 888 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP), and with a diameter of ∼196 arcsec. This source has phenomenological similarities to odd radio circles (ORCs). Significant differences to the known ORCs – a flatter radio spectral index, the lack of a prominent central galaxy as a possible host, and larger apparent size – suggest that J0624–6948 may be a different type of object. We argue that the most plausible explanation for J0624–6948 is an intergalactic supernova remnant due to a star that resided in the LMC outskirts that had undergone a single-degenerate type Ia supernova, and we are seeing its remnant expand into a rarefied, intergalactic environment. We also examine if a massive star or a white dwarf binary ejected from either galaxy could be the supernova progenitor. Finally, we consider several other hypotheses for the nature of the object, including the jets of an active galactic nucleus (30Dor) or the remnant of a nearby stellar super-flare.
Publisher: American Astronomical Society
Date: 13-06-2008
DOI: 10.1086/590343
Publisher: American Astronomical Society
Date: 05-12-2006
DOI: 10.1086/510670
Publisher: American Astronomical Society
Date: 10-2023
Publisher: Oxford University Press (OUP)
Date: 27-11-2017
Publisher: American Astronomical Society
Date: 15-11-2012
Publisher: American Astronomical Society
Date: 30-04-2014
Publisher: Oxford University Press (OUP)
Date: 22-04-2016
DOI: 10.1093/MNRAS/STW949
Publisher: American Astronomical Society
Date: 11-08-2008
Publisher: Oxford University Press (OUP)
Date: 04-11-2022
Abstract: Young star clusters enable us to study the effects of stellar rotation on an ensemble of stars of the same age and across a wide range in stellar mass and are therefore ideal targets for understanding the consequences of rotation on stellar evolution. We combine MUSE spectroscopy with HST photometry to measure the projected rotational velocities (Vsin i) of 2184 stars along the split main sequence and on the main sequence turn-off (MSTO) of the 100 Myr-old massive ($10^5\\, {\\rm M_{\\odot }}$) star cluster NGC 1850 in the Large Magellanic Cloud. At fixed magnitude, we observe a clear correlation between Vsin i and colour, in the sense that fast rotators appear redder. The average Vsin i values for stars on the blue and red branches of the split main sequence are $\\sim \\! 100\\, {\\rm km\\, s^{-1}}$ and $\\sim \\! 200\\, {\\rm km\\, s^{-1}}$, respectively. The values correspond to about $25-30{{\\ \\rm per\\ cent}}$ and $50-60{{\\ \\rm per\\ cent}}$ of the critical rotation velocity and imply that rotation rates comparable to those observed in field stars of similar masses can explain the split main sequence. Our spectroscopic s le contains a rich population of ∼200 fast rotating Be stars. The presence of shell features suggests that 23 per cent of them are observed through their decretion discs, corresponding to a disc opening angle of 15 degrees. These shell stars can significantly alter the shape of the MSTO, hence care should be taken when interpreting this photometric feature. Overall, our findings impact our understanding of the evolution of young massive clusters and provide new observational constraints for testing stellar evolutionary models.
Publisher: American Astronomical Society
Date: 29-03-2016
Publisher: American Astronomical Society
Date: 15-12-2016
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 07-2019
End Date: 05-2022
Amount: $500,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2010
End Date: 12-2016
Amount: $560,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2012
End Date: 12-2016
Amount: $390,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2017
End Date: 05-2022
Amount: $805,054.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 12-2020
Amount: $340,160.00
Funder: Australian Research Council
View Funded Activity