ORCID Profile
0000-0002-4569-016X
Current Organisation
Australian National University
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Astronomical and Space Sciences | Cosmology and Extragalactic Astronomy | Astronomical sciences | Stellar Astronomy and Planetary Systems | Pattern Recognition and Data Mining | Astronomical sciences not elsewhere classified | Astronomical instrumentation | Astronomical and Space Instrumentation
Publisher: IEEE
Date: 12-2017
Publisher: Oxford University Press (OUP)
Date: 12-08-2016
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2022
Publisher: Oxford University Press (OUP)
Date: 17-06-2017
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: American Astronomical Society
Date: 06-12-2011
Publisher: Oxford University Press (OUP)
Date: 04-2007
Publisher: Cambridge University Press (CUP)
Date: 03-2004
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2022
Publisher: Zenodo
Date: 2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2013
Publisher: American Astronomical Society
Date: 20-05-2005
DOI: 10.1086/429552
Publisher: EDP Sciences
Date: 26-03-2007
Publisher: Springer Science and Business Media LLC
Date: 09-02-2016
Publisher: IEEE
Date: 05-2017
Publisher: Research Square Platform LLC
Date: 03-05-2022
DOI: 10.21203/RS.3.RS-1557549/V1
Abstract: We study the dependence of the stochastic variability of QSOs on luminosity, wavelength and thermal timescale in their accretion disks. We use over 5,000 of the most luminous known QSOs with light curves of almost nightly cadence spanning years of observations from the NASA/ATLAS project, which provides 2 billion magnitude pairs for a bootstrap analysis. The results depend on which timescales are included in the analysis: when we only consider timescales months, we find a robust behaviour for the whole s le. This behaviour is consistent with an un-d ed random walk on the thermal timescales predicted by thin-disk models. We find a variability litude of log(A/A 0 ) ≈1/2×log(Δt/t th ). On shorter timescales, we observe a suppression of the litude due to light travel-time filtering, which could be used to measure sizes of accretion disks.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2023
Publisher: IEEE
Date: 05-2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2021
Publisher: IEEE
Date: 09-2012
Publisher: EDP Sciences
Date: 10-2020
DOI: 10.1051/0004-6361/202038505
Abstract: The physics of gravity on cosmological scales affects both the rate of assembly of large-scale structure and the gravitational lensing of background light through this cosmic web. By comparing the litude of these different observational signatures, we can construct tests that can distinguish general relativity from its potential modifications. We used the latest weak gravitational lensing dataset from the Kilo-Degree Survey, KiDS-1000, in conjunction with overlapping galaxy spectroscopic redshift surveys, BOSS and 2dFLenS, to perform the most precise existing litude-ratio test. We measured the associated E G statistic with 15 − 20% errors in five Δ z = 0.1 tomographic redshift bins in the range 0.2 z 0.7 on projected scales up to 100 h −1 Mpc. The scale-independence and redshift-dependence of these measurements are consistent with the theoretical expectation of general relativity in a Universe with matter density Ω m = 0.27 ± 0.04. We demonstrate that our results are robust against different analysis choices, including schemes for correcting the effects of source photometric redshift errors, and we compare the performance of angular and projected galaxy-galaxy lensing statistics.
Publisher: Oxford University Press (OUP)
Date: 14-09-2020
Abstract: We study the utility of broad-band colours in the SkyMapper Southern Survey for selecting Seyfert galaxies at low luminosity. We find that the u − v index, built from the ultraviolet u and violet v filters, separates normal galaxies, starburst galaxies, and type-1 active galactic nuclei (AGNs). This u − v index is not sensitive to age or metallicity in a stellar population but is instead a quenching-and-bursting indicator in galaxies and detects power-law continua in type-1 AGNs. Using over 25 000 galaxies at z & 0.1 from 6dFGS, we find a selection cut based on u − v and central u band brightness that identifies type-1 AGNs. By eyeballing 6dFGS spectra we classify new Seyfert galaxies of type 1 to 1.8. Our s le includes eight known Changing-Look AGNs (CLAGNs), two of which show such strong variability that they move across the selection cut during the 5 yr of SkyMapper observations in DR3, along mixing sequences of nuclear and host galaxy light. We identify 46 CLAGN candidates in our s le, one of which has been reported as a Type IIn supernova. We show that this transient persists for at least 5 yr and marks a flare in a Seyfert-1 period of a new CLAGN.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2021
Publisher: EDP Sciences
Date: 28-08-2007
Publisher: EDP Sciences
Date: 20-01-2005
Publisher: Institution of Engineering and Technology (IET)
Date: 09-2015
Publisher: AIP
Date: 1997
DOI: 10.1063/1.54044
Publisher: Oxford University Press (OUP)
Date: 07-06-2023
Abstract: Given the anisotropic emission from quasar accretion discs, their viewing angle affects estimates of the quasar luminosity, black hole mass, and Eddington ratio. Discs appear overluminous when viewed pole-on and underluminous when viewed at high inclination. In radio-quiet quasars, the viewing angle is usually unknown, although spectroscopic indicators have been proposed. Here, we use a recently discovered universality in the variability structure function (SF) of quasar light curves (LCs), where all quasars show the same SF when clocks run in units of orbital time-scale. As an offset from the mean relation can be caused by incorrect orbital time-scales and thus incorrect luminosities, we correlate these offsets with suggested inclination indicators. We derive SFs from NASA/Asteroid Terrestrial-impact Last Alert System (ATLAS) LCs spanning ∼6 yr of observation, using a s le of 183 luminous quasars with measured H β lines as well as 753 quasars with C iv and Mg ii lines. Starting from the proposed orientation indicators, we expect quasars with narrower H β lines and with more blueshifted C iv lines to be viewed more pole-on and thus appear overluminous. In contrast, our SF analysis finds that presumed pole-on discs appear underluminous, consistently for both line indicators. We discuss possible explanations for the behaviour of quasars with highly blueshifted C iv lines irrespective of inclination angle, including dusty outflows that might render the accretion disc underluminous and flatter disc temperature profiles with longer orbital time-scales than in thin-disc models but reach no satisfying conclusion.
Publisher: American Astronomical Society
Date: 09-12-2003
DOI: 10.1086/381388
Publisher: Cambridge University Press (CUP)
Date: 2020
DOI: 10.1017/PASA.2020.39
Abstract: Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
Publisher: Springer-Verlag
Date: 2001
DOI: 10.1007/10854354_19
Publisher: IEEE
Date: 09-2012
Publisher: Oxford University Press (OUP)
Date: 11-03-2009
Publisher: Oxford University Press (OUP)
Date: 13-02-2021
Abstract: We have conducted a systematic survey for z & 0.04 active Galactic nuclei (AGNs) that may have changed spectral class over the past decade. We use SkyMapper, Pan-STARRS and the Véron-Cetty & Véron catalogue to search the entire sky for these ‘changing-look’ AGNs (CLAGNs) using a variety of selection methods, where Pan-STARRS has a coverage of 3$\\pi$ steradians (sky north of Declination −30○) and SkyMapper has coverage of ∼21000 $~\\rm {deg^2}$ (sky south of Declination 0○). We use small aperture photometry to measure how colour and flux have changed over time, where a change may indicate a change in spectral type. Optical colour and flux are used as a proxy for changing Hα equivalent width, while WISE 3.4 μm flux is used to look for changes in the hot dust component. We have identified four AGNs with varying spectra selected using our optical colour selection method. Three AGNs were confirmed from recent observations with WiFeS on the 2.3 m telescope at Siding Spring and the other was identified from archival spectra alone. From this, we identify two new CLAGNs NGC 1346 and 2MASX J20075129–1108346. We also recover Mrk 915 and Mrk 609, which are known to have varying spectra in the literature, but they do not meet our specific criteria for CLAGNs.
Publisher: Oxford University Press (OUP)
Date: 03-2007
Publisher: IEEE
Date: 12-2014
Publisher: Oxford University Press (OUP)
Date: 07-07-2022
Abstract: Binaries consisting of a hot subdwarf star and an accreting white dwarf (WD) are sources of gravitational wave radiation at low frequencies and possible progenitors of Type Ia supernovae if the WD mass is large enough. Here, we report the discovery of the third binary known of this kind: It consists of a hot subdwarf O (sdO) star and a WD with an orbital period of 3.495 h and an orbital shrinkage of 0.1 s in 6 yr. The sdO star overfills its Roche lobe and likely transfers mass to the WD via an accretion disc. From spectroscopy, we obtain an effective temperature of $T_{\\mathrm{eff}}=54\\, 240\\pm 1840$ K and a surface gravity of log g = 4.841 ± 0.108 for the sdO star. From the light curve analysis, we obtain an sdO mass of MsdO = 0.55 M⊙ and a mass ratio of q = MWD/MsdO = 0.738 ± 0.001. Also, we estimate that the disc has a radius of $\\sim\\!0.41\\ \\mathrm{R}_\\odot$ and a thickness of $\\sim\\!0.18\\ \\mathrm{R}_\\odot$. The origin of this binary is probably a common envelope ejection channel, where the progenitor of the sdO star is either a red giant branch star or, more likely, an early asymptotic giant branch star the sdO star will subsequently evolve into a WD and merge with its WD companion, likely resulting in an R Coronae Borealis (R CrB) star. The outstanding feature in the spectrum of this object is strong Ca H& K lines, which are blueshifted by ∼200 km s−1 and likely originate from the recently ejected common envelope, and we estimated that the remnant common envelope (CE) material in the binary system has a density $\\sim\\!6\\times 10^{-10}\\ {\\rm g\\, cm}^{-3}$.
Publisher: IEEE
Date: 12-2015
Publisher: Oxford University Press (OUP)
Date: 21-06-2007
Publisher: American Astronomical Society
Date: 13-10-2004
DOI: 10.1086/426138
Publisher: IOP Publishing
Date: 08-1999
DOI: 10.1086/316405
Publisher: Springer Netherlands
Date: 2004
Publisher: IEEE
Date: 11-2013
Publisher: Oxford University Press (OUP)
Date: 25-10-2019
Publisher: Cambridge University Press (CUP)
Date: 03-2004
Publisher: Oxford University Press (OUP)
Date: 18-05-2018
Publisher: Springer-Verlag
Date: 2005
DOI: 10.1007/10995020_116
Publisher: Springer-Verlag
Date: 2005
DOI: 10.1007/10995020_115
Publisher: American Astronomical Society
Date: 2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2021
Publisher: IEEE
Date: 06-2014
Publisher: American Astronomical Society
Date: 10-07-2007
DOI: 10.1086/518594
Publisher: EDP Sciences
Date: 06-11-2008
Publisher: Oxford University Press (OUP)
Date: 06-2002
Publisher: EDP Sciences
Date: 03-2001
Publisher: Oxford University Press (OUP)
Date: 30-04-2022
Abstract: We present a complete structural analysis of the ellipticals (E), diffuse bulges (dB), compact bulges (cB), and discs (D) within a redshift range 0 & z & 1, and stellar mass log10(M*/M⊙) ≥ 9.5 volume-limited s le drawn from the combined DEVILS and HST-COSMOS region. We use the profit code to profile over ∼35 000 galaxies for which visual classification into single or double component was pre-defined in Paper-I. Over this redshift range, we see a growth in the total stellar mass density (SMD) of a factor of 1.5. At all epochs we find that the dominant structure, contributing to the total SMD, is the disc, and holds a fairly constant share of $\\sim 60{{\\ \\rm per\\ cent}}$ of the total SMD from z = 0.8 to z = 0.2, dropping to $\\sim 30{{\\ \\rm per\\ cent}}$ at z = 0.0 (representing $\\sim 33{{\\ \\rm per\\ cent}}$ decline in the total disc SMD). Other classes (E, dB, and cB) show steady growth in their numbers and integrated stellar mass densities. By number, the most dramatic change across the full mass range is in the growth of diffuse bulges. In terms of total SMD, the biggest gain is an increase in massive elliptical systems, rising from 20 per cent at z = 0.8 to equal that of discs at z = 0.0 (30 per cent) representing an absolute mass growth of a factor of 2.5. Overall, we see a clear picture of the emergence and growth of all three classes of spheroids over the past 8 Gyr, and infer that in the later half of the Universe’s timeline spheroid-forming processes and pathways (secular evolution, mass-accretion, and mergers) appear to dominate mass transformation over quiescent disc growth.
Publisher: American Astronomical Society
Date: 03-01-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2014
Publisher: Cambridge University Press (CUP)
Date: 07-2004
Publisher: EDP Sciences
Date: 03-2002
Publisher: EDP Sciences
Date: 02-2021
DOI: 10.1051/0004-6361/202039063
Abstract: We present a joint cosmological analysis of weak gravitational lensing observations from the Kilo-Degree Survey (KiDS-1000), with redshift-space galaxy clustering observations from the Baryon Oscillation Spectroscopic Survey (BOSS) and galaxy-galaxy lensing observations from the overlap between KiDS-1000, BOSS, and the spectroscopic 2-degree Field Lensing Survey. This combination of large-scale structure probes breaks the degeneracies between cosmological parameters for in idual observables, resulting in a constraint on the structure growth parameter S 8 = σ 8 √(Ω m /0.3) = 0.766 −0.014 +0.020 , which has the same overall precision as that reported by the full-sky cosmic microwave background observations from Planck . The recovered S 8 litude is low, however, by 8.3 ± 2.6% relative to Planck . This result builds from a series of KiDS-1000 analyses where we validate our methodology with variable depth mock galaxy surveys, our lensing calibration with image simulations and null-tests, and our optical-to-near-infrared redshift calibration with multi-band mock catalogues and a spectroscopic-photometric clustering analysis. The systematic uncertainties identified by these analyses are folded through as nuisance parameters in our cosmological analysis. Inspecting the offset between the marginalised posterior distributions, we find that the S 8 -difference with Planck is driven by a tension in the matter fluctuation litude parameter, σ 8 . We quantify the level of agreement between the cosmic microwave background and our large-scale structure constraints using a series of different metrics, finding differences with a significance ranging between ∼3 σ , when considering the offset in S 8 , and ∼2 σ , when considering the full multi-dimensional parameter space.
Publisher: Cambridge University Press (CUP)
Date: 11-2019
DOI: 10.1017/S1743921318002077
Abstract: The SkyMapper Transient survey (SMT) is exploring variability in the southern sky by performing (a) a rolling search to discover and study supernovæ, and (b) a Target of Opportunity programme that uses the robotic SkyMapper Telescope at Siding Spring Observatory. The supernova survey is obtaining a non-targeted s le of Type Ia supernovæ (SNe Ia) at low redshifts, z 0.1, and studying other interesting transients found with the search strategy. We have a Target of Opportunity programme with an automatic response mechanism to search for optical counterparts to gravitational-wave and fast radio-burst events it benefits from SkyMapper’s large field of view of 5.7 sq. deg. and a rapid data reduction pipeline. We present first results of the SMT survey. The SMT pipeline can process and obtain potential candidates within 12 hours of observation. It disentangles real transients from processing artefacts using a machine-learning algorithm. To date, SMT has discovered over 60 spectroscopically confirmed supernovæ, several peculiar objects, and over 40 SNe Ia including one (SNIa 2016hhd) which was found within the first few days of explosion. We have also participated in searches for optical counterparts of gravitational waves, fast radio bursts and other transients, and have published observations of the optical counterpart of the gravitational-wave event GW170817. We also participate in coordinated observations with the Deeper Wider Faster programme, and the Kepler K2 cosmology project.
Publisher: EDP Sciences
Date: 2001
Publisher: Oxford University Press (OUP)
Date: 14-06-2018
Publisher: Oxford University Press (OUP)
Date: 22-05-2015
DOI: 10.1093/MNRAS/STV779
Publisher: American Astronomical Society
Date: 12-12-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2011
Publisher: Oxford University Press (OUP)
Date: 21-12-2022
Abstract: Changing-look active galactic nuclei (CLAGN) are AGN that change type as their broad emission lines appear or disappear, which is usually accompanied by strong flux changes in their blue featureless continuum. We search for turn-on CLAGN by selecting type-2 AGN from the spectroscopic Six-degree Field Galaxy Survey (6dFGS), whose colours, observed ∼15 yr later by the SkyMapper Southern Survey, are suggestive of type-1 AGN. Starting from 1092 type-2 AGN, we select 20 candidates for follow-up and confirm that 14 of them have changed into type-1 and are thus turn-on CLAGN further observations reveal 11 more turn-on CLAGN. While our search was not tailored to efficiently discover turn-off CLAGN, we discover two such cases as well. The result suggests a turn-on CLAGN rate of over 3 per cent over ∼15 yr and imply a total CLAGN rate of more than ∼6 per cent over this period. Finally, we present observations of AGN that are atypical for the CLAGN phenomenology, including J1109146 – a type-1 that did not appear as an AGN at all in 6dFGS J1406507 – the second reported changing-look narrow-line Seyfert 1 and J1340153 – a CLAGN with a change time-scale of 3 months.
Publisher: Oxford University Press (OUP)
Date: 10-2006
Publisher: Oxford University Press (OUP)
Date: 03-10-2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2016
Publisher: EDP Sciences
Date: 31-07-2006
Publisher: IEEE
Date: 09-2010
Publisher: American Astronomical Society
Date: 02-2022
Abstract: Accurate determinations of stellar parameters and distances for large complete s les of stars are keys for conducting detailed studies of the formation and evolution of our Galaxy. Here we present stellar atmospheric parameters (effective temperature, luminosity classifications, and metallicity) estimates for some 24 million stars determined from the stellar colors of SMSS DR2 and Gaia EDR3, based on training data sets with available spectroscopic measurements from previous high/medium/low-resolution spectroscopic surveys. The number of stars with photometric-metallicity estimates is 4–5 times larger than that collected by the current largest spectroscopic survey to date—LAMOST—over the course of the past decade. External checks indicate that the precision of the photometric-metallicity estimates are quite high, comparable to or slightly better than that derived from spectroscopy, with typical values around 0.05–0.15 dex for both dwarf and giant stars with [Fe/H] −2.01.0, 0.10–0.20 dex for giant stars with −2.0 [Fe/H] ≤ −1.0, and 0.20–0.25 dex for giant stars with [Fe/H] ≤ −2.0, and include estimates for stars as metal-poor as [Fe/H] ∼ −3.5, substantially lower than previous photometric techniques. Photometric-metallicity estimates are obtained for an unprecedented number of metal-poor stars, including a total of over three million metal-poor (MP [Fe/H] ≤ −1.0) stars, over half a million very metal-poor (VMP [Fe/H] ≤ −2.0) stars, and over 25,000 extremely metal-poor (EMP [Fe/H] ≤ −3.0) stars. Moreover, distances are determined for over 20 million stars in our s le. For the over 18 million s le stars with accurate Gaia parallaxes, stellar ages are estimated by comparing with theoretical isochrones. Astrometric information is provided for the stars in our catalog, along with radial velocities for ∼10% of our s le stars, taken from completed/ongoing large-scale spectroscopic surveys.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2018
Publisher: EDP Sciences
Date: 17-03-2003
Publisher: IEEE
Date: 07-2019
Publisher: Cambridge University Press (CUP)
Date: 2017
DOI: 10.1017/PASA.2017.41
Abstract: The Taipan galaxy survey (hereafter simply ‘Taipan’) is a multi-object spectroscopic survey starting in 2017 that will cover 2π steradians over the southern sky (δ ≲ 10°, | b | ≳ 10°), and obtain optical spectra for about two million galaxies out to z 0.4. Taipan will use the newly refurbished 1.2-m UK Schmidt Telescope at Siding Spring Observatory with the new TAIPAN instrument, which includes an innovative ‘Starbugs’ positioning system capable of rapidly and simultaneously deploying up to 150 spectroscopic fibres (and up to 300 with a proposed upgrade) over the 6° diameter focal plane, and a purpose-built spectrograph operating in the range from 370 to 870 nm with resolving power R ≳ 2000. The main scientific goals of Taipan are (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H 0 ) to 1% precision, and the growth rate of structure to 5% (ii) to make the most extensive map yet constructed of the total mass distribution and motions in the local Universe, using peculiar velocities based on improved Fundamental Plane distances, which will enable sensitive tests of gravitational physics and (iii) to deliver a legacy s le of low-redshift galaxies as a unique laboratory for studying galaxy evolution as a function of dark matter halo and stellar mass and environment. The final survey, which will be completed within 5 yrs, will consist of a complete magnitude-limited s le ( i ⩽ 17) of about 1.2 × 10 6 galaxies supplemented by an extension to higher redshifts and fainter magnitudes ( i ⩽ 18.1) of a luminous red galaxy s le of about 0.8 × 10 6 galaxies. Observations and data processing will be carried out remotely and in a fully automated way, using a purpose-built automated ‘virtual observer’ software and an automated data reduction pipeline. The Taipan survey is deliberately designed to maximise its legacy value by complementing and enhancing current and planned surveys of the southern sky at wavelengths from the optical to the radio it will become the primary redshift and optical spectroscopic reference catalogue for the local extragalactic Universe in the southern sky for the coming decade.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2021
Publisher: EDP Sciences
Date: 11-2005
Publisher: Cambridge University Press (CUP)
Date: 07-2005
Publisher: IEEE
Date: 05-2017
Publisher: American Astronomical Society
Date: 2008
DOI: 10.1086/521080
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: EDP Sciences
Date: 25-11-2005
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2019
Publisher: Oxford University Press (OUP)
Date: 16-10-2019
Abstract: We present our search for flares from M dwarf stars in the SkyMapper Southern Survey DR1, which covers nearly the full Southern hemisphere with six-filter sequences that are repeatedly observed in the passbands uvgriz. This allows us to identify bona fide flares in single-epoch observations on time-scales of less than four minutes. Using a correlation-based outlier search algorithm we find 254 flare events in the litude range of Δu ∼ 0.1 to 5 mag. In agreement with previous work, we observe the flaring fraction of M dwarfs to increase from ∼30 to ∼1000 per million stars for spectral types M0 to M5. We also confirm the decrease in flare fraction with larger vertical distance from the Galactic plane which is expected from declining stellar activity with age. Based on precise distances from Gaia DR2, we find a steep decline in the flare fraction from the plane to 150 pc vertical distance and a significant flattening towards larger distances. We then reassess the strong type dependence in the flaring fraction with a volume-limited s le within a distance of 50 pc from the Sun: in this s le the trend disappears and we find instead a constant fraction of ∼1 650 per million stars for spectral types M1 to M5. Finally, large- litude flares with Δi 1 mag are very rare with a fraction of ∼0.5 per million M dwarfs. Hence, we expect that M-dwarf flares will not confuse SkyMapper’s search for kilonovae from gravitational-wave events. proper references for those databases (or follow their guideline on citation).
Publisher: IEEE
Date: 2013
Publisher: PeerJ
Date: 23-07-2018
DOI: 10.7717/PEERJ-CS.157
Abstract: We study the problem of combining active learning suggestions to identify informative training ex les by empirically comparing methods on benchmark datasets. Many active learning heuristics for classification problems have been proposed to help us pick which instance to annotate next. But what is the optimal heuristic for a particular source of data? Motivated by the success of methods that combine predictors, we combine active learners with bandit algorithms and rank aggregation methods. We demonstrate that a combination of active learners outperforms passive learning in large benchmark datasets and removes the need to pick a particular active learner a priori. We discuss challenges to finding good rewards for bandit approaches and show that rank aggregation performs well.
Publisher: Springer Science and Business Media LLC
Date: 07-2020
Publisher: Oxford University Press (OUP)
Date: 31-10-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2023
Publisher: Cambridge University Press (CUP)
Date: 08-2006
DOI: 10.1017/S1743921306010465
Abstract: Classifying Object by Medium-Band Observations in 17 filters (COMBO-17) has already produced a very accurate picture of galaxy evolution since z~1 based on 25000 galaxies in 17 medium optical bands. We now extend the range of reliable multi-color redshifts with COMBO-17+4, a deep optical-NIR survey which will combine the existing optical data set of COMBO-17 with near infrared observation in three medium bands: Y(λ/Δλ = 1040/80nm), J1(1190/130nm) and J2(1320/130nm) and one broad band H(1650/300nm). The NIR bands extend the photometric redshift range to z~2.1. COMBO 17+4 will provide the first large s le of galaxies ( ) at 1 z with a redshifts accuracy of Δz .03(1+z). Three fields are observed: Abell 901, Abell 226 and the COMBO 11h-field, for a total coverage of 0.77□ 2 of the sky. Each COMBO 17+4 field measures 31 × 30 sqarcmin. The NIR bands are observed with the Omega2000 camera at Calar Alto Observatory in Spain. The scientific goals for this study are multiple. COMBO-17+4 will enable us to establish the luminosity function for the red sequence and blue galaxies in the redshift range 1 z . Also it will be possible to determine the formation history at z=2 by analyzing the width of the red sequence galaxies. Moreover this survey will provide several thousand of in idual galaxy masses (with an accuracy %) obtained with Spectral Energy Distribution (SED) template fitting. Once the masses are obtained the mass function will provide a useful tool to test the hierarchical model of evolution of galaxies by checking whether the massive red sequence galaxies (logM .5) are already in place at z .5 (9Gyr). We present first results from the full 21 bands photometry in half of the Abell 901 field. It allows us to study not only z galaxies but also the stellar content of several hundred cluster galaxies.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2013
Publisher: EDP Sciences
Date: 03-2001
Publisher: EDP Sciences
Date: 10-2001
Publisher: Cambridge University Press (CUP)
Date: 2018
DOI: 10.1017/PASA.2018.22
Abstract: We report the discovery of the ultra-luminous quasi-stellar object SMSS J215728.21−360215.1 with magnitude z = 16.9 and W4 = 7.42 at redshift 4.75. Given absolute magnitudes of M 145, AB = −29.3, M 300, AB = −30.12, and log L bol / L bol, ⊙ = 14.84, it is the quasi-stellar object with the highest unlensed UV-optical luminosity currently known in the Universe. It was found by combining proper-motion data from Gaia DR2 with photometry from SkyMapper DR1 and the Wide-field Infrared Survey Explorer. In the GAIA database, it is an isolated single source and thus unlikely to be strongly gravitationally lensed. It is also unlikely to be a beamed source as it is not discovered in the radio domain by either NRAO-VLA Sky Survey or Sydney University Molonglo Southern Survey. It is classed as a weak-emission-line quasi-stellar object and possesses broad absorption line features. A lightcurve from ATLAS spanning the time from 2015 October to 2017 December shows little sign of variability.
Publisher: Oxford University Press (OUP)
Date: 21-07-2009
Publisher: American Astronomical Society
Date: 18-05-2009
Publisher: American Astronomical Society
Date: 05-09-2017
Publisher: IEEE
Date: 03-2015
Publisher: Cambridge University Press (CUP)
Date: 07-2004
Publisher: IEEE
Date: 06-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2020
Publisher: American Astronomical Society
Date: 10-07-2008
DOI: 10.1086/588459
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2012
Publisher: Cambridge University Press (CUP)
Date: 08-2006
DOI: 10.1017/S1743921306005321
Abstract: Observations in the Chandra Deep Field South (CDFS) have provided us with a useful set of data in the optical ( COMBO-17 ), near-infrared (GOODS JHK), and mid-infrared (GOODS IRAC bands 1,2) wavelength regimes to test and improve a new spectral galaxy template library, designed to operate in the rest-frame wavelength range between 0.1 and 5 microns. In this range the stellar continuum and emission lines from HII regions dominate the Spectral Energy Distribution (SED) of galaxies. The new library is based on a self-consistent two-burst model, that has been developed in order to reproduce the star formation histories of different types of galaxies more accurately than single-burst histories and thus provides a better match to real galaxy spectra, as well as more reliable mass-to-light ratios. The spectral library is built by using a population synthesis code (PEGASE) assuming a Kroupa (2003) initial mass function. An old burst of exponentially decaying star formation with an initial metallicity of 0.1 solar is followed by a very recent (60 Myr old) second burst in order to reproduce the spectra of actively star forming blue galaxies. In addition, the templates include dust extinction of various strengths. For the multi-color classification the spectral library is red-shifted between z + 0 and z + 2.5 and converted into the 21 colors which have been observed by COMBO-17 plus its near- and mid-infrared extensions provided by the public GOODS data.
Publisher: IEEE
Date: 2013
Publisher: Oxford University Press (OUP)
Date: 14-10-2014
Publisher: American Astronomical Society
Date: 10-2022
Abstract: The Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will detect an unprecedentedly large s le of actively accreting supermassive black holes with typical accretion disk (AD) sizes of a few light days. This brings us to face challenges in the reverberation mapping (RM) measurement of AD sizes in active galactic nuclei using interband continuum delays. We examine the effect of LSST cadence strategies on AD RM using our metric AGN _ TimeLagMetric . It accounts for redshift, cadence, the magnitude limit, and magnitude corrections for dust extinction. Running our metric on different LSST cadence strategies, we produce an atlas of the performance estimations for LSST photometric RM measurements. We provide an upper limit on the estimated number of quasars for which the AD time lag can be computed within 0 z 7 using the features of our metric. We forecast that the total counts of such objects will increase as the mean s ling rate of the survey decreases. The AD time lag measurements are expected for sources in each deep drilling field (DDF (10 deg 2 )) in any filter, with the redshift distribution of these sources peaking at z ≈ 1. We find the LSST observation strategies with a good cadence (≲5 days) and a long cumulative season (∼9 yr), as proposed for LSST DDF, are favored for the AD size measurement. We create synthetic LSST light curves for the most suitable DDF cadences and determine RM time lags to demonstrate the impact of the best cadences based on the proposed metric.
Publisher: Oxford University Press (OUP)
Date: 05-11-2014
Publisher: EDP Sciences
Date: 05-2021
DOI: 10.1051/0004-6361/202039805
Abstract: We present constraints on extensions to the standard cosmological model of a spatially flat Universe governed by general relativity, a cosmological constant (Λ), and cold dark matter (CDM) by varying the spatial curvature Ω K , the sum of the neutrino masses ∑ m ν , the dark energy equation of state parameter w , and the Hu-Sawicki f ( R ) gravity f R 0 parameter. With the combined 3 × 2 pt measurements of cosmic shear from the Kilo-Degree Survey (KiDS-1000), galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), and galaxy-galaxy lensing from the overlap between KiDS-1000, BOSS, and the spectroscopic 2-degree Field Lensing Survey, we find results that are fully consistent with a flat ΛCDM model with Ω K = 0.011 −0.057 +0.054 , ∑ m ν 1.76 eV (95% CL), and w = −0.99 −0.13 +0.11 . The f R 0 parameter is unconstrained in our fully non-linear f ( R ) cosmic shear analysis. Considering three different model selection criteria, we find no clear preference for either the fiducial flat ΛCDM model or any of the considered extensions. In addition to extensions to the flat ΛCDM parameter space, we also explore restrictions to common subsets of the flat ΛCDM parameter space by fixing the litude of the primordial power spectrum to the Planck best-fit value, as well as adding external data from supernovae and lensing of the cosmic microwave background (CMB). Neither the beyond-ΛCDM models nor the imposed restrictions explored in this analysis are able to resolve the ∼3 σ tension in S 8 between the 3 × 2 pt constraints and the Planck temperature and polarisation data, with the exception of w CDM, where the S 8 tension is resolved. The tension in the w CDM case persists, however, when considering the joint S 8 − w parameter space. The joint flat ΛCDM CMB lensing and 3 × 2 pt analysis is found to yield tight constraints on Ω m = 0.307 −0.013 +0.008 , σ 8 = 0.769 −0.010 +0.022 , and S 8 = 0.779 −0.013 +0.013 .
Publisher: Oxford University Press (OUP)
Date: 10-2004
Publisher: Oxford University Press (OUP)
Date: 02-2004
Publisher: Oxford University Press (OUP)
Date: 02-03-2023
Abstract: We develop an accretion disc (AD)-fitting method, utilizing thin and slim disc models and Bayesian inference with the Markov-Chain Monte Carlo approach, testing it on the most luminous known quasar, SMSS J215728.21-360215.1, at redshift z = 4.692. With a spectral energy distribution constructed from near-infrared spectra and broad-band photometry, the AD models find a black hole mass of $\\log (M_{\\rm {AD}}/{\\rm M}_{\\odot }) = 10.31^{+0.17}_{-0.14}$ with an anisotropy-corrected bolometric luminosity of $\\log {(L_{\\rm {bol}}/\\rm {erg\\, s^{-1}})} = 47.87 \\pm 0.10$ and derive an Eddington ratio of $0.29^{+0.11}_{-0.10}$ as well as a radiative efficiency of $0.09^{+0.05}_{-0.03}$. Using the near-infrared spectra, we estimate the single-epoch virial black hole mass estimate to be log (MSE/M⊙) = 10.33 ± 0.08, with a monochromatic luminosity at 3000 Å of $\\log {(L(\\rm {3000{\\AA}})/\\rm {erg\\, s^{-1}})} = 47.66 \\pm 0.01$. As an independent approach, AD fitting has the potential to complement the single-epoch virial mass method in obtaining stronger constraints on properties of massive quasar black holes across a wide range of redshifts.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2016
Publisher: Springer-Verlag
Date: 2005
DOI: 10.1007/10995020_59
Publisher: Oxford University Press (OUP)
Date: 10-2004
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2010
Publisher: Oxford University Press (OUP)
Date: 23-06-2018
Publisher: Springer-Verlag
Date: 2001
DOI: 10.1007/10849171_40
Publisher: EDP Sciences
Date: 02-2022
DOI: 10.1051/0004-6361/202142074
Abstract: Context. The populations of small bodies of the Solar System (asteroids, comets, and Kuiper Belt objects) are used to constrain the origin and evolution of the Solar System. Their orbital distribution and composition distribution are both required to track the dynamical pathway from their formation regions to their current locations. Aims. We aim to increase the s le of Solar System objects (SSOs) that have multifilter photometry and compositional taxonomy. Methods. We searched for moving objects in the SkyMapper Southern Survey. We used the predicted SSO positions to extract photometry and astrometry from the SkyMapper frames. We then applied a suite of filters to clean the catalog from false-positive detections. We finally used the near-simultaneous photometry to assign a taxonomic class to objects. Results. We release a catalog of 880 528 in idual observations, consisting of 205 515 known and unique SSOs. The catalog completeness is estimated to be about 97% down to V = 18 mag and the purity is higher than 95% for known SSOs. The near-simultaneous photometry provides either three, two, or a single color that we use to classify 117 356 SSOs with a scheme consistent with the widely used Bus-DeMeo taxonomy. Conclusions. The present catalog contributes significantly to the s le of asteroids with known surface properties (about 40% of main-belt asteroids down to an absolute magnitude of 16). We will release more observations of SSOs with future SkyMapper data releases.
Publisher: American Astronomical Society
Date: 10-2007
DOI: 10.1086/518836
Publisher: IEEE
Date: 10-2018
Publisher: Oxford University Press (OUP)
Date: 27-01-2017
DOI: 10.1093/MNRAS/STX228
Publisher: IEEE
Date: 12-2010
Publisher: IEEE
Date: 11-2009
Publisher: American Astronomical Society
Date: 05-11-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2014
Publisher: Oxford University Press (OUP)
Date: 21-07-2005
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2013
Publisher: Oxford University Press (OUP)
Date: 11-2005
Publisher: Oxford University Press (OUP)
Date: 11-03-2009
Publisher: IEEE
Date: 09-2009
Publisher: Oxford University Press (OUP)
Date: 15-12-2009
Publisher: Oxford University Press (OUP)
Date: 05-2003
Publisher: WORLD SCIENTIFIC
Date: 10-2004
Publisher: No publisher found
Date: 2016
Publisher: Cambridge University Press (CUP)
Date: 08-2020
DOI: 10.1017/S1743921319005131
Abstract: I discuss the photometric calibration of the SkyMapper Southern Survey, our adopted methods and what we learned from comparisons with external catalogues.
Publisher: Oxford University Press (OUP)
Date: 05-09-2007
Publisher: Springer Science and Business Media LLC
Date: 19-04-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2020
Publisher: IEEE
Date: 05-2011
Publisher: IEEE
Date: 06-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2022
Publisher: American Astronomical Society
Date: 12-2007
DOI: 10.1086/522088
Publisher: Oxford University Press (OUP)
Date: 11-03-2001
Publisher: American Astronomical Society
Date: 30-12-2008
Publisher: EDP Sciences
Date: 04-2010
Publisher: IEEE
Date: 09-2012
Publisher: American Astronomical Society
Date: 29-07-2022
Abstract: Quasars behind the Galactic plane (GPQs) are important astrometric references and valuable probes of Galactic gas, yet the search for GPQs is difficult due to severe extinction and source crowding in the Galactic plane. In this paper, we present a s le of 204 spectroscopically confirmed GPQs at ∣ b ∣ 20°, 191 of which are new discoveries. This GPQ s le covers a wide redshift range from 0.069 to 4.487. For the subset of 230 observed GPQ candidates, the lower limit of the purity of quasars is 85.2%, and the lower limit of the fraction of stellar contaminants is 6.1%. Using a multicomponent spectral fitting, we measure the emission line and continuum flux of the GPQs, and estimate their single-epoch virial black hole masses. Due to selection effects raised from Galactic extinction and target magnitude, these GPQs have higher black hole masses and continuum luminosities in comparison to the SDSS DR7 quasar s le. The spectral-fitting results and black hole mass estimates are compiled into a main spectral catalog, and an extended spectral catalog of GPQs. The successful identifications prove the reliability of both our GPQ selection methods and the GPQ candidate catalog, shedding light on the astrometric and astrophysical programs that make use of a large s le of GPQs in the future.
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: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2011
Publisher: IEEE
Date: 12-2012
Publisher: IEEE
Date: 05-2017
Publisher: Oxford University Press (OUP)
Date: 23-10-2015
Publisher: American Astronomical Society
Date: 11-2004
DOI: 10.1086/424385
Publisher: Springer-Verlag
Date: 2005
DOI: 10.1007/10995020_74
Publisher: EDP Sciences
Date: 04-2003
Publisher: Springer-Verlag
Date: 2005
DOI: 10.1007/10995020_79
Publisher: American Astronomical Society
Date: 20-03-2006
DOI: 10.1086/499931
Publisher: Oxford University Press (OUP)
Date: 31-12-2015
Publisher: EDP Sciences
Date: 27-11-2009
Publisher: IEEE
Date: 05-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2014
Publisher: EDP Sciences
Date: 2001
Publisher: IEEE
Date: 12-2016
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2022
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: IEEE
Date: 12-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2020
Publisher: Oxford University Press (OUP)
Date: 29-09-2022
Abstract: We study the relationship between Galactic location (R, Z) and photometric activity for 3.6 million M dwarf stars within 1 kpc of the Sun. For this purpose, we identify 906 unique flare events as a proxy for magnetic activity from the SkyMapper Southern Survey Data Release 3. We adopt vertical distance |Z| from the Galactic disc as a proxy for age and confirm a strong trend of flaring fraction decreasing with growing stellar age. Among M dwarfs within 50 pc of the Sun, we find a flaring fraction of one in 1500, independent of spectral type from M2 to M7, suggesting that these stars are all in a flare-saturated young evolutionary stage. We find a hint of a kink in the slope of the overall flare fraction near 100 pc from the plane, where a steep decline begins this slope change is visible for mid-type M dwarfs (M3–M5), suggesting it is not an artefact of mixing spectral type. Together with the Sloan Digital Sky Survey Hα emission, this trend is additional evidence that the activity fraction of M dwarfs depends on Galactic height and activity lifetime. While there is a hint of flattening of the overall activity fraction above |Z| ≈ 500 pc, our data do not constrain this further. Within ∼500 pc distance from the Sun, we find no sign of radial disc gradients in flare activity, which may only be revealed by s les covering a larger radial range.
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2012
Publisher: EDP Sciences
Date: 08-2018
DOI: 10.1051/0004-6361/201731942
Abstract: We present a machine-learning photometric redshift (ML photo- z ) analysis of the Kilo-Degree Survey Data Release 3 (KiDS DR3), using two neural-network based techniques: ANNz2 and MLPQNA. Despite limited coverage of spectroscopic training sets, these ML codes provide photo- z s of quality comparable to, if not better than, those from the Bayesian Photometric Redshift (BPZ) code, at least up to z phot ≲ 0.9 and r ≲ 23.5. At the bright end of r ≲ 20, where very complete spectroscopic data overlapping with KiDS are available, the performance of the ML photo- z s clearly surpasses that of BPZ, currently the primary photo- z method for KiDS. Using the Galaxy And Mass Assembly (GAMA) spectroscopic survey as calibration, we furthermore study how photo- z s improve for bright sources when photometric parameters additional to magnitudes are included in the photo- z derivation, as well as when VIKING and WISE infrared (IR) bands are added. While the fiducial four-band ugri setup gives a photo- z bias 〈 δz /(1 + z )〉 = −2 × 10 −4 and scatter σ δz/(1+z) 0.022 at mean 〈 z 〉 = 0.23, combining magnitudes, colours, and galaxy sizes reduces the scatter by ~7% and the bias by an order of magnitude. Once the ugri and IR magnitudes are joined into 12-band photometry spanning up to 12 μ m, the scatter decreases by more than 10% over the fiducial case. Finally, using the 12 bands together with optical colours and linear sizes gives 〈 δz /(1 + z )〉 4 × 10 −5 and σ δz /(1+ z ) 0.019. This paper also serves as a reference for two public photo- z catalogues accompanying KiDS DR3, both obtained using the ANNz2 code. The first one, of general purpose, includes all the 39 million KiDS sources with four-band ugri measurements in DR3. The second dataset, optimised for low-redshift studies such as galaxy-galaxy lensing, is limited to r ≲ 20, and provides photo- z s of much better quality than in the full-depth case thanks to incorporating optical magnitudes, colours, and sizes in the GAMA-calibrated photo- z derivation.
Publisher: IEEE
Date: 12-2010
Publisher: Cambridge University Press (CUP)
Date: 2022
DOI: 10.1017/PASA.2022.36
Abstract: We report the discovery of a bright ( $g = 14.5$ mag (AB), $K = 11.9$ mag (Vega)) quasar at redshift $z=0.83$ — the optically brightest (unbeamed) quasar at $z .4$ . SMSS J114447.77-430859.3, at a Galactic latitude of $b=+18.1^{\\circ}$ , was identified by its optical colours from the SkyMapper Southern Survey (SMSS) during a search for symbiotic binary stars. Optical and near-infrared spectroscopy reveals broad Mg ii , H $\\unicode{x03B2}$ , H $\\unicode{x03B1}$ , and Pa $\\unicode{x03B2}$ emission lines, from which we measure a black hole mass of $\\log_{10}\\! (M_{\\mathrm{BH}}/\\mathrm{M}_{\\odot}) = 9.4 \\pm 0.5$ . With its high luminosity, $L_{\\mathrm{bol}} = (4.7\\pm1.0)\\times10^{47}\\,\\mathrm{erg\\,s}^{-1}$ or $M_{i}(z=2) = -29.74$ mag (AB), we estimate an Eddington ratio of $\\approx1.4$ . As the most luminous quasar known over the last ${\\sim}$ 9 Gyr of cosmic history, having a luminosity $8\\times$ greater than 3C 273, the source offers a range of potential follow-up opportunities.
Publisher: American Astronomical Society
Date: 22-09-2009
Publisher: American Astronomical Society
Date: 03-06-2009
Publisher: American Astronomical Society
Date: 22-04-2016
Publisher: Springer Science and Business Media LLC
Date: 2003
Publisher: Oxford University Press (OUP)
Date: 30-11-2016
Publisher: EDP Sciences
Date: 29-07-2005
Publisher: Oxford University Press (OUP)
Date: 30-06-2020
Abstract: From near-infrared spectroscopic measurements of the Mg ii emission line doublet, we estimate the black hole (BH) mass of the quasar, SMSS J215728.21–360215.1, as being (3.4 ± 0.6) × 1010 M⊙ and refine the redshift of the quasar to be z = 4.692. SMSS J2157 is the most luminous known quasar, with a 3000 Å luminosity of (4.7 ± 0.5) × 1047 erg s−1 and an estimated bolometric luminosity of 1.6 × 1048 erg s−1, yet its Eddington ratio is only ∼0.4. Thus, the high luminosity of this quasar is a consequence of its extremely large BH – one of the most massive BHs at z & 4.
Publisher: Cambridge University Press (CUP)
Date: 2017
DOI: 10.1017/PASA.2017.24
Abstract: The SkyMapper 1.3 m telescope at Siding Spring Observatory has now begun regular operations. Alongside the Southern Sky Survey, a comprehensive digital survey of the entire southern sky, SkyMapper will carry out a search for supernovae and other transients. The search strategy, covering a total footprint area of ~2 000 deg 2 with a cadence of ⩽5 d, is optimised for discovery and follow-up of low-redshift type Ia supernovae to constrain cosmic expansion and peculiar velocities. We describe the search operations and infrastructure, including a parallelised software pipeline to discover variable objects in difference imaging simulations of the performance of the survey over its lifetime public access to discovered transients and some first results from the Science Verification data.
Publisher: Oxford University Press (OUP)
Date: 11-04-2022
Abstract: The elemental abundances in the broad-line regions of high-redshift quasars trace the chemical evolution in the nuclear regions of massive galaxies in the early Universe. In this work, we study metallicity-sensitive broad emission-line flux ratios in rest-frame UV spectra of 25 high-redshift (5.8 & z & 7.5) quasars observed with the VLT/X-shooter and Gemini/GNIRS instruments, ranging over $\\log \\left({{M}_{\\rm {BH}}/\\rm {M}_{\\odot }}\\right) = 8.4-9.8$ in black hole mass and $\\log \\left(\\rm {L}_{\\rm {bol}}/\\rm {erg \\, s}^{-1}\\right) = 46.7-47.7$ in bolometric luminosity. We fit in idual spectra and composites generated by binning across quasar properties: bolometric luminosity, black hole mass, and blueshift of the C iv line, finding no redshift evolution in the emission-line ratios by comparing our high-redshift quasars to lower redshift (2.0 & z & 5.0) results presented in the literature. Using cloudy-based locally optimally emitting cloud photoionization model relations between metallicity and emission-line flux ratios, we find the observable properties of the broad emission lines to be consistent with emission from gas clouds with metallicity that are at least 2–4 times solar. Our high-redshift measurements also confirm that the blueshift of the C iv emission line is correlated with its equivalent width, which influences line ratios normalized against C iv. When accounting for the C iv blueshift, we find that the rest-frame UV emission-line flux ratios do not correlate appreciably with the black hole mass or bolometric luminosity.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2021
Publisher: IEEE
Date: 05-2019
Publisher: Springer Science and Business Media LLC
Date: 09-03-2010
Publisher: IEEE
Date: 12-2017
Publisher: American Astronomical Society
Date: 10-08-2007
DOI: 10.1086/519294
Publisher: EDP Sciences
Date: 04-2003
Publisher: AIP
Date: 2003
DOI: 10.1063/1.1579377
Publisher: Oxford University Press (OUP)
Date: 04-12-2020
Abstract: Searches for optical transients are usually performed with a cadence of days to weeks, optimized for supernova discovery. The optical fast transient sky is still largely unexplored, with only a few surveys to date having placed meaningful constraints on the detection of extragalactic transients evolving at sub-hour time-scales. Here, we present the results of deep searches for dim, minute-time-scale extragalactic fast transients using the Dark Energy Camera, a core facility of our all-wavelength and all-messenger Deeper, Wider, Faster programme. We used continuous 20 s exposures to systematically probe time-scales down to 1.17 min at magnitude limits g & 23 (AB), detecting hundreds of transient and variable sources. Nine candidates passed our strict criteria on duration and non-stellarity, all of which could be classified as flare stars based on deep multiband imaging. Searches for fast radio burst and gamma-ray counterparts during simultaneous multifacility observations yielded no counterparts to the optical transients. Also, no long-term variability was detected with pre-imaging and follow-up observations using the SkyMapper optical telescope. We place upper limits for minute-time-scale fast optical transient rates for a range of depths and time-scales. Finally, we demonstrate that optical g-band light-curve behaviour alone cannot discriminate between confirmed extragalactic fast transients such as prompt GRB flashes and Galactic stellar flares.
Publisher: EDP Sciences
Date: 16-10-2007
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: Oxford University Press (OUP)
Date: 06-08-2018
Publisher: Oxford University Press (OUP)
Date: 13-10-2011
Publisher: American Astronomical Society
Date: 09-01-2004
DOI: 10.1086/379232
Publisher: Oxford University Press (OUP)
Date: 21-01-2004
Publisher: IEEE
Date: 09-2012
Publisher: Oxford University Press (OUP)
Date: 21-10-2020
Abstract: The most luminous quasars at high-redshift harbour the fastest growing and most massive black holes in the early Universe. They are exceedingly rare and hard to find. Here, we present our search for the most luminous quasars in the redshift range from z = 4.5 to 5 using data from SkyMapper, Gaia, and WISE. We use colours to select likely high-redshift quasars and reduce the stellar contamination of the candidate set with parallax and proper motion data. In ∼12 500 deg2 of Southern sky, we find 92 candidates brighter than Rp = 18.2. Spectroscopic follow-up has revealed 21 quasars at z ≥ 4 (16 of which are within z = [4.5, 5]), as well as several red quasars, Broad-Absorption-Line (BAL) quasars and objects with unusual spectra, which we tentatively label OFeLoBALQSOs at redshifts of z ≈ 1 to 2. This work lifts the number of known bright z ≥ 4.5 quasars in the Southern hemisphere from 10 to 26 and brings the total number of quasars known at Rp & 18.2 and z ≥ 4.5 to 42.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2012
Publisher: EDP Sciences
Date: 06-2013
Publisher: American Astronomical Society
Date: 30-10-2023
Publisher: Springer-Verlag
Date: 2001
DOI: 10.1007/10849171_73
Publisher: Oxford University Press (OUP)
Date: 11-09-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2018
Publisher: American Astronomical Society
Date: 23-03-2018
Publisher: Oxford University Press (OUP)
Date: 06-2006
Publisher: American Astronomical Society
Date: 20-02-2001
DOI: 10.1086/319095
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: Oxford University Press (OUP)
Date: 04-07-2019
Abstract: We detail a new fast radio burst (FRB) survey with the Molonglo Radio Telescope, in which six FRBs were detected between 2017 June and 2018 December. By using a real-time FRB detection system, we captured raw voltages for five of the six events, which allowed for coherent dedispersion and very high time resolution (10.24 $\\mu$s) studies of the bursts. Five of the FRBs show temporal broadening consistent with interstellar and/or intergalactic scattering, with scattering time-scales ranging from 0.16 to 29.1 ms. One burst, FRB181017, shows remarkable temporal structure, with three peaks each separated by 1 ms. We searched for phase-coherence between the leading and trailing peaks and found none, ruling out lensing scenarios. Based on this survey, we calculate an all-sky rate at 843 MHz of $98^{+59}_{-39}$ events sky−1 d−1 to a fluence limit of 8 Jy ms: a factor of 7 below the rates estimated from the Parkes and ASKAP telescopes at 1.4 GHz assuming the ASKAP-derived spectral index α = −1.6 (Fν ∝ να). Our results suggest that FRB spectra may turn over below 1 GHz. Optical, radio, and X-ray follow-up has been made for most of the reported bursts, with no associated transients found. No repeat bursts were found in the survey.
Publisher: Wiley
Date: 04-2021
DOI: 10.1111/MAPS.13653
Abstract: The June 2, 2018 impact of asteroid 2018 LA over Botswana is only the second asteroid detected in space prior to impacting over land. Here, we report on the successful recovery of meteorites. Additional astrometric data refine the approach orbit and define the spin period and shape of the asteroid. Video observations of the fireball constrain the asteroid's position in its orbit and were used to triangulate the location of the fireball's main flare over the Central Kalahari Game Reserve. Twenty‐three meteorites were recovered. A consortium study of eight of these classifies Motopi Pan as an HED polymict breccia derived from howardite, cumulate and basaltic eucrite, and diogenite lithologies. Before impact, 2018 LA was a solid rock of ~156 cm diameter with high bulk density ~2.85 g cm −3 , a relatively low albedo p V ~ 0.25, no significant opposition effect on the asteroid brightness, and an impact kinetic energy of ~0.2 kt. The orbit of 2018 LA is consistent with an origin at Vesta (or its Vestoids) and delivery into an Earth‐impacting orbit via the ν 6 resonance. The impact that ejected 2018 LA in an orbit toward Earth occurred 22.8 ± 3.8 Ma ago. Zircons record a concordant U‐Pb age of 4563 ± 11 Ma and a consistent 207 Pb/ 206 Pb age of 4563 ± 6 Ma. A much younger Pb‐Pb phosphate resetting age of 4234 ± 41 Ma was found. From this impact chronology, we discuss what is the possible source crater of Motopi Pan and the age of Vesta's Veneneia impact basin.
Publisher: American Astronomical Society
Date: 10-10-2005
DOI: 10.1086/432786
Publisher: IEEE
Date: 05-2019
Publisher: American Astronomical Society
Date: 20-06-2004
DOI: 10.1086/420778
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2016
Publisher: EDP Sciences
Date: 12-09-2006
Publisher: American Astronomical Society
Date: 09-04-2020
Publisher: EDP Sciences
Date: 14-12-2012
Publisher: American Astronomical Society
Date: 21-10-2009
Publisher: EDP Sciences
Date: 09-2003
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2011
Publisher: EDP Sciences
Date: 29-10-2020
DOI: 10.1051/0004-6361/202037693
Abstract: Context. Young solar analogs reaching the main sequence experience very strong magnetic activity, generating angular momentum losses through wind and mass ejections. Aims. We investigate signatures of magnetic fields and activity at the surface and in the prominence system of the ultra-rapid rotator V530 Per, a G-type solar-like member of the young open cluster α Persei. This object has a rotation period that is shorter than all stars with available magnetic maps. Methods. With a time-series of spectropolarimetric observations gathered with ESPaDOnS over two nights on the Canada-France-Hawaii Telescope, we reconstructed the surface brightness and large-scale magnetic field of V530 Per using the Zeeman-Doppler imaging method, assuming an oblate stellar surface. We also estimated the short term evolution of the brightness distribution through latitudinal differential rotation. Using the same data set, we finally mapped the spatial distribution of prominences through tomography of the H α emission. Results. The brightness map is dominated by a large, dark spot near the pole, accompanied by a complex distribution of bright and dark features at lower latitudes. Taking the brightness map into account, the magnetic field map is reconstructed as well. Most of the large-scale magnetic field energy is stored in the toroidal field component. The main radial field structure is a positive region of about 500 G, at the location of the dark polar spot. The brightness map of V530 Per is sheared by solar-like differential rotation, with roughly a solar value for the difference in rotation rate between the pole and equator. It is important to note that H α is observed in emission and it is mostly modulated by the stellar rotation period over one night. The prominence system is organized in a ring at the approximate location of the corotation radius, and displays significant evolution between the two observing nights. Conclusions. V530 Per is the first ex le of a solar-type star to have its surface magnetic field and prominences mapped together, which will bring important observational constraints to better understand the role of slingshot prominences in the angular momentum evolution of the most active stars.
Publisher: IEEE
Date: 09-2013
Publisher: American Astronomical Society
Date: 20-09-1999
DOI: 10.1086/307708
Publisher: Cambridge University Press (CUP)
Date: 2023
DOI: 10.1017/PASA.2023.7
Abstract: We describe the first results from the All-sky BRIght, Complete Quasar Survey (AllBRICQS), which aims to discover the last remaining optically bright quasars. We present 156 spectroscopically confirmed quasars (140 newly identified) having $|b| ^{\circ}$ . 152 of the quasars have Gaia DR3 magnitudes brighter than $B_{P}=16.5$ or $R_{P}=16$ mag, while four are slightly fainter. The quasars span a redshift range of $z=0.07-3.93$ . In particular, we highlight the properties of J0529-4351 at $z=3.93$ , which, if unlensed, is one of the most intrinsically luminous quasars in the Universe. The AllBRICQS sources have been selected by combining data from the Gaia and WISE all-sky satellite missions, and we successfully identify quasars not flagged as candidates by Gaia Data Release 3. We expect the completeness to be $\approx$ 96% within our magnitude and latitude limits, while the preliminary results indicate a selection purity of $\approx$ 96%. The optical spectroscopy used for source classification will also enable detailed quasar characterisation, including black hole mass measurements and identification of foreground absorption systems. The AllBRICQS sources will greatly enhance the number of quasars available for high-signal-to-noise follow-up with present and future facilities.
Publisher: IEEE
Date: 06-2021
Publisher: American Astronomical Society
Date: 20-12-2005
DOI: 10.1086/497679
Publisher: IEEE
Date: 06-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: Oxford University Press (OUP)
Date: 03-05-2018
Publisher: Oxford University Press (OUP)
Date: 05-04-2018
DOI: 10.1093/MNRAS/STY859
Publisher: Oxford University Press (OUP)
Date: 08-11-2011
Publisher: American Astronomical Society
Date: 10-01-2008
DOI: 10.1086/523661
Publisher: Oxford University Press (OUP)
Date: 05-12-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2014
Publisher: Oxford University Press (OUP)
Date: 23-11-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2012
Publisher: American Astronomical Society
Date: 26-04-2007
DOI: 10.1086/518690
Publisher: American Astronomical Society
Date: 29-01-2021
Publisher: Cambridge University Press (CUP)
Date: 2021
DOI: 10.1017/PASA.2021.17
Abstract: We present an overview of the SkyMapper optical follow-up programme for gravitational-wave event triggers from the LIGO/Virgo observatories, which aims at identifying early GW170817-like kilonovae out to $\\sim200\\,\\mathrm{Mpc}$ distance. We describe our robotic facility for rapid transient follow-up, which can target most of the sky at $\\delta +10\\deg $ to a depth of $i_\\mathrm{AB}\\approx 20\\,\\mathrm{mag}$ . We have implemented a new software pipeline to receive LIGO/Virgo alerts, schedule observations and examine the incoming real-time data stream for transient candidates. We adopt a real-bogus classifier using ensemble-based machine learning techniques, attaining high completeness ( $\\sim98\\%$ ) and purity ( $\\sim91\\%$ ) over our whole magnitude range. Applying further filtering to remove common image artefacts and known sources of transients, such as asteroids and variable stars, reduces the number of candidates by a factor of more than 10. We demonstrate the system performance with data obtained for GW190425, a binary neutron star merger detected during the LIGO/Virgo O3 observing c aign. In time for the LIGO/Virgo O4 run, we will have deeper reference images allowing transient detection to $i_\\mathrm{AB}\\approx 21\\,\\mathrm{mag}$ .
Publisher: American Astronomical Society
Date: 20-11-2006
DOI: 10.1086/508408
Publisher: EDP Sciences
Date: 08-2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2021
Publisher: Cambridge University Press (CUP)
Date: 08-2006
DOI: 10.1017/S1743921306005370
Abstract: One of the key predictions of hierarchical galaxy formation models is that a significant fraction of elliptical galaxies form in late merging events. One of the most important diagnostics of such an assembly is the existence of blue spheroidal galaxies, which have spheroid-dominated morphologies and blue colors indicating recent star formation, as an intermediate step in the evolution of elliptical galaxies.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2021
Publisher: Oxford University Press (OUP)
Date: 03-2007
Publisher: Oxford University Press (OUP)
Date: 08-2004
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 15-06-2022
Publisher: Elsevier BV
Date: 11-2005
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2022
Publisher: IEEE
Date: 12-2011
Publisher: Oxford University Press (OUP)
Date: 09-2006
Publisher: Oxford University Press (OUP)
Date: 07-07-2020
Abstract: Changing look active galactic nuclei (CLAGNs) are rare cases of AGNs, where the continuum flux increases/decreases and the broad emission lines appear/disappear within short time-scales. These extreme changes challenge our understanding of accretion disc dynamics. We present a s le of four new CLAGNs at 0.026 & z & 0.107, which were found by cross-matching the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey with AGNs from the SDSS spectroscopic data base. Our results show that the selection criteria of $\gt \mathopen |0.5\mathclose |$ mag change in SDSS-g band is ineffective at lower redshifts. This is, in part, due to the fact that the g band is probing a different part of the AGNs spectral energy distribution at these redshifts. The bigger issue is that the galaxy continuum dominates the spectrum and thus overwhelms any variation of the AGNs continuum that might contribute to photometric variations. This suggests the need to use different methods for future low-redshift CLAGNs searches.
Publisher: Oxford University Press (OUP)
Date: 08-04-2019
DOI: 10.1093/MNRAS/STZ958
Abstract: Here, we report on the detection and verification of fast radio burst FRB 180301, which occurred on utc 2018 March 1 during the Breakthrough Listen observations with the Parkes telescope. Full-polarization voltage data of the detection were captured – a first for non-repeating FRBs – allowing for coherent de-dispersion and additional verification tests. The coherently de-dispersed dynamic spectrum of FRB 180301 shows complex, polarized frequency structure over a small fractional bandwidth. As FRB 180301 was detected close to the geosynchronous satellite band during a time of known 1–2 GHz satellite transmissions, we consider whether the burst was due to radio interference emitted or reflected from an orbiting object. Based on the pre-ponderance of our verification tests, we cannot conclusively determine FRB 180301 to be either astrophysical or anthropogenic in origin.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2020
Publisher: IEEE
Date: 06-2013
Publisher: American Astronomical Society
Date: 20-05-2006
DOI: 10.1086/501447
Publisher: American Astronomical Society
Date: 23-07-2010
Publisher: Zenodo
Date: 2018
Publisher: Springer Netherlands
Date: 2007
Publisher: EDP Sciences
Date: 2013
Publisher: American Astronomical Society
Date: 07-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2013
Publisher: American Association for the Advancement of Science (AAAS)
Date: 17-08-2007
Abstract: Type Ia supernovae are important cosmological distance indicators. Each of these bright supernovae supposedly results from the thermonuclear explosion of a white dwarf star that, after accreting material from a companion star, exceeds some mass limit, but the true nature of the progenitor star system remains controversial. Here we report the spectroscopic detection of circumstellar material in a normal type Ia supernova explosion. The expansion velocities, densities, and dimensions of the circumstellar envelope indicate that this material was ejected from the progenitor system. In particular, the relatively low expansion velocities suggest that the white dwarf was accreting material from a companion star that was in the red-giant phase at the time of the explosion.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2018
Publisher: Oxford University Press (OUP)
Date: 04-2008
Publisher: EDP Sciences
Date: 29-06-2004
Publisher: American Astronomical Society
Date: 20-03-2002
DOI: 10.1086/338763
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2015
Publisher: Springer Science and Business Media LLC
Date: 02-02-2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2013
Publisher: IEEE
Date: 06-2013
Publisher: EDP Sciences
Date: 27-10-2009
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2020
Publisher: Oxford University Press (OUP)
Date: 09-08-2016
Publisher: American Astronomical Society
Date: 02-1999
DOI: 10.1086/311846
Publisher: IEEE
Date: 09-2010
Publisher: Oxford University Press (OUP)
Date: 10-01-2022
Abstract: We search for ultraluminous Quasi-Stellar Objects (QSOs) at high redshift using photometry from the SkyMapper Southern Survey Data Release 3 (DR3), in combination with 2MASS, VHS DR6, VIKING DR5, AllWISE, and CatWISE2020, as well as parallaxes and proper motions from Gaia DR2 and eDR3. We report 142 newly discovered Southern QSOs at 3.8 & z & 5.5, of which 126 have M145 & −27 AB mag and are found in a search area of 14 486 deg2. This Southern s le, utilizing the Gaia astrometry to offset wider photometric colour criteria, achieves unprecedented completeness for an ultraluminous QSO search at high redshift. In combination with already known QSOs, we construct a s le that is & per cent complete for M145 & −27.33 AB mag at z = 4.7 and for M145 & −27.73 AB mag at z = 5.4. We derive the bright end of the QSO luminosity function at rest frame 145 nm for z = 4.7–5.4 and measure its slope to be β = −3.60 ± 0.37 and β = −3.38 ± 0.32 for two different estimates of the faint-end QSO density adopted from the literature. We also present the first z ∼ 5 QSO luminosity function at rest frame 300 nm.
Publisher: EDP Sciences
Date: 14-05-2004
Publisher: Research Square Platform LLC
Date: 30-06-2023
DOI: 10.21203/RS.3.RS-2834908/V1
Abstract: Quasars are supermassive black holes feasting on surrounding matter, which make them outshine their host galaxies. Around a million quasars have been cat- alogued in the Universe by probing deeper and using new methods for discovery. In this work, we study the properties of the most luminous of all quasars found so far. It has been overlooked until recently, which demonstrates that modern all-sky surveys have much to reveal. The black hole in this quasar accretes around one solar mass per day onto an existing mass of 15 billion solar masses. In this process its accretion disc alone releases a radiative energy that is equivalent to the output from between 365 and 640 trillion Suns. The range is mostly due to the unknown viewing angle of the disc, which radiates more intensely near its polar sight lines than at grazing angles to the disc.
Publisher: American Astronomical Society
Date: 20-10-2004
DOI: 10.1086/423234
Publisher: IEEE
Date: 05-2018
Publisher: American Astronomical Society
Date: 06-2004
DOI: 10.1086/420885
Publisher: American Astronomical Society
Date: 20-10-2004
DOI: 10.1086/423233
Publisher: IEEE
Date: 09-2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2018
Publisher: EDP Sciences
Date: 28-06-2006
Publisher: American Astronomical Society
Date: 10-09-2005
DOI: 10.1086/431659
Publisher: Oxford University Press (OUP)
Date: 20-09-2018
Publisher: Oxford University Press (OUP)
Date: 17-12-2018
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 07-2019
End Date: 12-2022
Amount: $375,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 12-2023
Amount: $595,295.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2011
End Date: 03-2018
Amount: $20,600,000.00
Funder: Australian Research Council
View Funded Activity