ORCID Profile
0000-0001-7440-8832
Current Organisations
Geneva University
,
Center for Frontier Science, Chiba University
,
Waseda University
,
自然科学研究機構国立天文台/National Astronomical Observatory of Japan
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Sensory Processes, Perception and Performance | Psychology | Behavioural Ecology |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Biological Sciences | Expanding Knowledge in Psychology and Cognitive Sciences | Expanding Knowledge in Technology
Related Links
Publications
A3COSMOS: the dust attenuation of star-forming galaxies at z = 2.5–4.0 from the COSMOS-ALMA archive
Publisher: Oxford University Press (OUP)
Date: 22-11-2019
Abstract: We present an analysis of the dust attenuation of star-forming galaxies at z = 2.5–4.0 through the relationship between the UV spectral slope (β), stellar mass (M*), and the infrared excess (IRX = LIR/LUV) based on far-infrared continuum observations from the Atacama Large Millimeter/sub-millimeter Array (ALMA). Our study exploits the full ALMA archive over the COSMOS field processed by the A3COSMOS team, which includes an unprecedented s le of ∼1500 galaxies at z ∼ 3 as primary or secondary targets in ALMA band 6 or 7 observations with a median continuum sensitivity of 126 $\\rm {\\mu Jy\\, beam}^{-1}$ (1σ). The detection rate is highly mass dependent, decreasing drastically below log (M*/M⊙) = 10.5. The detected galaxies show that the IRX–β relationship of massive (log M*/M⊙ & 10) main-sequence galaxies at z = 2.5–4.0 is consistent with that of local galaxies, while starbursts are generally offset by $\\sim 0.5\\, {\\rm dex}$ to larger IRX values. At the low-mass end, we derive upper limits on the infrared luminosities through stacking of the ALMA data. The combined IRX–M* relation at $\\rm {log\\, ({\\it M}_{\\ast }/\\mathrm{M}_{\\odot })\\gt 9}$ exhibits a significantly steeper slope than reported in previous studies at similar redshifts, implying little dust obscuration at log M*/M⊙ & 10. However, our results are consistent with earlier measurements at z ∼ 5.5, indicating a potential redshift evolution between z ∼ 2 and z ∼ 6. Deeper observations targeting low-mass galaxies will be required to confirm this finding.
Significant Dust-obscured Star Formation in Luminous Lyman-break Galaxies at z ∼ 7–8
Publisher: American Astronomical Society
Date: 03-2022
Abstract: We make use of Atacama Large Millimeter/submillimeter Array continuum observations of 15 luminous Lyman-break galaxies at z ∼ 7–8 to probe their dust-obscured star formation. These observations are sensitive enough to probe obscured star formation rates (SFRs) of 20 M ⊙ yr −1 (3 σ ). Six of the targeted galaxies show significant (≥3 σ ) dust-continuum detections, more than doubling the number of known dust-detected galaxies at z 6.5. Their IR luminosities range from 2.7 × 10 11 L ⊙ to 1.1 × 10 12 L ⊙ , equivalent to obscured SFRs of 25 to 101 M ⊙ yr −1 . We use our results to quantify the correlation of the infrared excess (IRX) on the UV-continuum slope β UV and stellar mass. Our results are most consistent with a Small Magellanic Cloud (SMC) attenuation curve for intrinsic UV-slopes β UV , intr of −2.63 and most consistent with an attenuation curve in between SMC and Calzetti for β UV , intr slopes of −2.23, assuming a dust temperature T d of 50 K. Our fiducial IRX–stellar mass results at z ∼ 7–8 are consistent with marginal evolution from z ∼ 0. We then show how both results depend on T d . For our six dust-detected sources, we estimate their dust masses and find that they are consistent with dust production from supernovae if the dust destruction is low ( %). Finally we determine the contribution of dust-obscured star formation to the SFR density for UV luminous ( H −21.5 mag: ≳1.7 L * UV ) z ∼ 7–8 galaxies, finding that the total SFR density at z ∼ 7 and z ∼ 8 from bright galaxies is 0.20 − 0.10 + 0.10 dex and 0.23 − 0.09 + 0.06 dex higher, respectively i.e., ∼ 1 3 of the star formation in ≳1.7 L * UV galaxies at z ∼ 7–8 is obscured by dust.
THE KMOS3DSURVEY: DESIGN, FIRST RESULTS, AND THE EVOLUTION OF GALAXY KINEMATICS FROM 0.7 ⩽z⩽ 2.7
Publisher: American Astronomical Society
Date: 30-01-2015
THE ALMA SPECTROSCOPIC SURVEY IN THE HUBBLE ULTRA DEEP FIELD: SEARCH FOR [${\rm{C}}\,{\rm{II}}$] LINE AND DUST EMISSION IN 6 <z< 8 GALAXIES
Publisher: American Astronomical Society
Date: 08-12-2016
Automated Mining of the ALMA Archive in the COSMOS Field (A3COSMOS). II. Cold Molecular Gas Evolution out to Redshift 6
Publisher: American Astronomical Society
Date: 23-12-2019
Probing star formation and ISM properties using galaxy disk inclination
Publisher: EDP Sciences
Date: 07-2018
DOI: 10.1051/0004-6361/201732255
Abstract: Disk galaxies at intermediate redshift ( z ~ 0.7) have been found in previous work to display more optically thick behaviour than their local counterparts in the rest-frame B -band surface brightness, suggesting an evolution in dust properties over the past ~6 Gyr. We compare the measured luminosities of face-on and edge-on star-forming galaxies at different wavelengths (Ultraviolet (UV), mid-infrared (MIR), far-infrared (FIR), and radio) for two well-matched s les of disk-dominated galaxies: a local Sloan Digital Sky Survey (SDSS)-selected s le at z ~ 0.07 and a s le of disks at z ~ 0.7 drawn from Cosmic Evolution Survey (COSMOS). We have derived correction factors to account for the inclination dependence of the parameters used for s le selection. We find that typical galaxies are transparent at MIR wavelengths at both redshifts, and that the FIR and radio emission is also transparent as expected. However, reduced sensitivity at these wavelengths limits our analysis we cannot rule out opacity in the FIR or radio. Ultra-violet attenuation has increased between z ~ 0 and z ~ 0.7, with the z ~ 0.7 s le being a factor of ~3.4 more attenuated. The larger UV attenuation at z ~ 0.7 can be explained by more clumpy dust around nascent star-forming regions. There is good agreement between the fitted evolution of the normalisation of the SFR UV versus 1 − cos( i ) trend (interpreted as the clumpiness fraction) and the molecular gas fraction/dust fraction evolution of galaxies found out to z 1.
The ALMA REBELS Survey. Epoch of Reionization giants: Properties of dusty galaxies at z ≈ 7
Publisher: Oxford University Press (OUP)
Date: 21-02-2022
Abstract: We analyse FIR dust continuum measurements for 14 galaxies (redshift z ≈ 7) in the ALMA Reionization Era Bright Emission Line Survey (REBELS) Large Program to derive their physical properties. Our model uses three input data, i.e. (a) the UV spectral slope, β, (b) the observed UV continuum flux at 1500 Å, F1500, (c) the observed continuum flux at $\\approx 158\\, \\mu$m, F158, and considers Milky Way (MW) and SMC extinction curves, along with different dust geometries. We find that REBELS galaxies have 28−90.5 per cent of their star formation obscured the total (UV+IR) star formation rates are in the range $31.5 \\lt {\\rm SFR}/({\\rm M}_\\odot \\, {\\rm yr}^{-1}) \\lt 129.5$. The s le-averaged dust mass and temperature are $(1.3\\pm 1.1)\\times 10^7 \\, \\mathrm{M}_\\odot$ and 52 ± 11 K, respectively. However, in some galaxies dust is particularly abundant (REBELS-14, $M^{\\prime }_{\\rm d} \\approx 3.4 \\times 10^7 \\, \\mathrm{M}_\\odot$), or hot (REBELS-18, $T^{\\prime }_{\\rm d} \\approx 67$ K). The dust distribution is compact (& .3 kpc for 70 per cent of the galaxies). The inferred dust yield per supernova is $0.1 \\le y_{\\rm d}/\\, \\mathrm{M}_\\odot \\le 3.3$, with 70 per cent of the galaxies requiring $y_{\\rm d} \\lt 0.25 \\, \\mathrm{M}_\\odot$. Three galaxies (REBELS-12, 14, 39) require $y_{\\rm d} \\gt 1 \\, \\mathrm{M}_\\odot$, which is likely inconsistent with pure SN production, and might require dust growth via accretion of heavy elements from the interstellar medium. With the SFR predicted by the model and a MW extinction curve, REBELS galaxies detected in [C ii] nicely follow the local LCII−SFR relation, and are approximately located on the Kennicutt–Schmidt relation. The s le-averaged gas depletion time is $0.11\\, y_{\\rm P}^{-2}$ Gyr, where yP is the ratio of the gas-to-stellar distribution radius. For some systems, a solution simultaneously matching the observed (β, F1500, F158) values cannot be found. This occurs when the index Im = (F158/F1500)/(β − βint), where βint is the intrinsic UV slope, exceeds $I_m^{*}\\approx 1120$ for an MW curve. For these objects, we argue that the FIR and UV emitting regions are not co-spatial, questioning the use of the IRX–β relation.
UNCOVER: The Growth of the First Massive Black Holes from JWST/NIRSpec—Spectroscopic Redshift Confirmation of an X-Ray Luminous AGN at z = 10.1
Publisher: American Astronomical Society
Date: 09-2023
Normal, dust-obscured galaxies in the epoch of reionization
Publisher: Springer Science and Business Media LLC
Date: 22-09-2021
DOI: 10.1038/S41586-021-03846-Z
Abstract: Over the past decades, rest-frame ultraviolet (UV) observations have provided large s les of UV luminous galaxies at redshift (z) greater than 6 (refs.
UNCOVER: A NIRSpec Identification of a Broad-line AGN at z = 8.50
Publisher: American Astronomical Society
Date: 26-10-2023
A Search for H-Dropout Lyman Break Galaxies at z ∼ 12–16
Publisher: American Astronomical Society
Date: 04-2022
Abstract: We present two bright galaxy candidates at z ∼ 12–13 identified in our H -dropout Lyman break selection with 2.3 deg 2 near-infrared deep imaging data. These galaxy candidates, selected after careful screening of foreground interlopers, have spectral energy distributions showing a sharp discontinuity around 1.7 μ m, a flat continuum at 2–5 μ m, and nondetections at .2 μ m in the available photometric data sets, all of which are consistent with a z 12 galaxy. An ALMA program targeting one of the candidates shows a tentative 4 σ [O iii ] 88 μ m line at z = 13.27, in agreement with its photometric redshift estimate. The number density of the z ∼ 12–13 candidates is comparable to that of bright z ∼ 10 galaxies and is consistent with a recently proposed double-power-law luminosity function rather than the Schechter function, indicating little evolution in the abundance of bright galaxies from z ∼ 4 to 13. Comparisons with theoretical models show that the models cannot reproduce the bright end of rest-frame ultraviolet luminosity functions at z ∼ 10–13. Combined with recent studies reporting similarly bright galaxies at z ∼ 9–11 and mature stellar populations at z ∼ 6–9, our results indicate the existence of a number of star-forming galaxies at z 10, which will be detected with upcoming space missions such as the James Webb Space Telescope, Nancy Grace Roman Space Telescope, and GREX-PLUS.
The ALMA REBELS Survey: discovery of a massive, highly star-forming, and morphologically complex ULIRG at z = 7.31
Publisher: Oxford University Press (OUP)
Date: 09-05-2023
Abstract: We present Atacama Large Millimeter/Submillimeter Array (ALMA) [C ii] and ∼158 $\\rm \\mu m$ continuum observations of REBELS-25, a massive, morphologically complex ultra-luminous infrared galaxy (ULIRG LIR = $1.5^{+0.8}_{-0.5} \\times 10^{12}$ L⊙) at z = 7.31, spectroscopically confirmed by the Reionization Era Bright Emission Line Survey (REBELS) ALMA Large Programme. REBELS-25 has a significant stellar mass of $M_{*} = \\mbox{$ 8^{+4}_{-2} \\times 10^{9} $}{} ~\\mbox{M$_\\odot $}{}$. From dust-continuum and ultraviolet observations, we determine a total obscured + unobscured star formation rate of SFR $= \\mbox{$199^{+101}_{-63}$}{} ~ \\mbox{M$_\\odot $}~ \\mbox{${\\rm yr}$}^{-1}$. This is about four times the SFR estimated from an extrapolated main sequence. We also infer a [C ii]-based molecular gas mass of $M_{{\\rm H}_{2}} = \\mbox{$5.1^{+5.1}_{-2.6} \\times 10^{10}$}{} ~\\mbox{M$_\\odot $}{}$, implying a molecular gas depletion time of $t_{\\rm depl, {\\rm H}_{2}} = \\mbox{$0.3^{+0.3}_{-0.2} $}{}$ Gyr. We observe a [C ii] velocity gradient consistent with disc rotation, but given the current resolution we cannot rule out a more complex velocity structure such as a merger. The spectrum exhibits excess [C ii] emission at large positive velocities (∼500 km s−1), which we interpret as either a merging companion or an outflow. In the outflow scenario, we derive a lower limit of the mass outflow rate of 200 $\\mbox{M$_\\odot $}~ \\mbox{${\\rm yr}$}^{-1}$, which is consistent with expectations for a star-formation-driven outflow. Given its large stellar mass, SFR, and molecular gas reservoir ∼700 Myr after the big bang, we explore the future evolution of REBELS-25. Considering a simple, conservative model assuming an exponentially declining star formation history, constant star formation efficiency, and no additional gas inflow, we find that REBELS-25 has the potential to evolve into a galaxy consistent with the properties of high-mass quiescent galaxies recently observed at z ∼ 4.
The ALMA REBELS Survey: Average [C ii] 158 μm Sizes of Star-forming Galaxies from z ∼ 7 to z ∼ 4
Publisher: American Astronomical Society
Date: 08-2022
Abstract: We present the average [C ii ] 158 μ m emission line sizes of UV-bright star-forming galaxies at z ∼ 7. Our results are derived from a stacking analysis of [C ii ] 158 μ m emission lines and dust continua observed by the Atacama Large Millimeter/submillimeter Array (ALMA), taking advantage of the large program Reionization Era Bright Emission Line Survey. We find that the average [C ii ] emission at z ∼ 7 has an effective radius r e of 2.2 ± 0.2 kpc. It is ≳2× larger than the dust continuum and the rest-frame UV emission, in agreement with recently reported measurements for z ≲ 6 galaxies. Additionally, we compared the average [C ii ] size with 4 z 6 galaxies observed by the ALMA Large Program to INvestigate [C ii ] at Early times (ALPINE). By analyzing [C ii ] sizes of 4 z 6 galaxies in two redshift bins, we find an average [C ii ] size of r e = 2.2 ± 0.2 kpc and r e = 2.5 ± 0.2 kpc for z ∼ 5.5 and z ∼ 4.5 galaxies, respectively. These measurements show that star-forming galaxies, on average, show no evolution in the size of the [C ii ] 158 μ m emitting regions at redshift between z ∼ 7 and z ∼ 4. This finding suggests that the star-forming galaxies could be morphologically dominated by gas over a wide redshift range.
JWST UNCOVER: Extremely Red and Compact Object at z phot ≃ 7.6 Triply Imaged by A2744
Publisher: American Astronomical Society
Date: 25-07-2023
Abstract: Recent JWST/NIRCam imaging taken for the ultra-deep UNCOVER program reveals a very red dropout object at z phot ≃ 7.6, triply imaged by the galaxy cluster A2744 ( z d = 0.308). All three images are very compact, i.e., unresolved, with a delensed size upper limit of r e ≲ 35 pc. The images have apparent magnitudes of m F444W ∼ 25−26 AB, and the magnification-corrected absolute UV magnitude of the source is M UV,1450 = −16.81 ± 0.09. From the sum of observed fluxes and from a spectral energy distribution (SED) analysis, we obtain estimates of the bolometric luminosities of the source of L bol ≳ 10 43 erg s −1 and L bol ∼ 10 44 –10 46 erg s −1 , respectively. Based on its compact, point-like appearance, its position in color–color space, and the SED analysis, we tentatively conclude that this object is a UV-faint dust-obscured quasar-like object, i.e., an active galactic nucleus at high redshift. We also discuss other alternative origins for the object’s emission features, including a massive star cluster, Population III, supermassive, or dark stars, or a direct-collapse black hole. Although populations of red galaxies at similar photometric redshifts have been detected with JWST, this object is unique in that its high-redshift nature is corroborated geometrically by lensing, that it is unresolved despite being magnified—and thus intrinsically even more compact—and that it occupies notably distinct regions in both size–luminosity and color–color space. Planned UNCOVER JWST/NIRSpec observations, scheduled in Cycle 1, will enable a more detailed analysis of this object.
Related Organisations
自然科学研究機構国立天文台/National Astronomical Observatory Of Japan
Location: Japan
Related Funding Activities
Discovery Projects - Grant ID: DP140100431
Start Date: 2014
End Date: 12-2017
Amount: $360,000.00
Funder: Australian Research Council
View Funded Activity