Publications
471 results found
Garratt TK, Geach JE, Tamura Y, et al., 2023, The SCUBA-2 Large eXtragalactic Survey: 850 μm map, catalogue and the bright-end number counts of the XMM-LSS field, Monthly Notices of the Royal Astronomical Society, Vol: 520, Pages: 3669-3687, ISSN: 0035-8711
We present 850 μm imaging of the XMM-LSS field observed for 170 h as part of the James Clerk Maxwell Telescope SCUBA-2 Large eXtragalactic Survey (S2LXS). S2LXS XMM-LSS maps an area of 9 deg2, reaching a moderate depth of 1σ 4 mJy beam−1. This is the largest contiguous area of extragalactic sky mapped by James Clerk Maxwell Telescope (JCMT) at 850 μm to date. The wide area of the S2LXS XMM-LSS survey allows us to probe the ultra-bright (S850μm 15 mJy), yet rare submillimetre population. We present the S2LXS XMM-LSS catalogue, which comprises 40 sources detected at >5σ significance, with deboosted flux densities in the range of 7–48 mJy. We robustly measure the bright-end of the 850 μm number counts at flux densities >7 mJy, reducing the Poisson errors compared to existing measurements. The S2LXS XMM-LSS observed number counts show the characteristic upturn at bright fluxes, expected to be motivated by local sources of submillimetre emission and high-redshift strongly lensed galaxies. We find that the observed 850 μm number counts are best reproduced by model predictions that include either strong lensing or source blending from a 15-arcsec beam, indicating that both may make an important contribution to the observed overabundance of bright single dish 850 μm selected sources. We make the S2LXS XMM-LSS 850 μm map and >5σ catalogue presented here publicly available.
Farrah D, Croker KS, Zevin M, et al., 2023, Observational Evidence for Cosmological Coupling of Black Holes and its Implications for an Astrophysical Source of Dark Energy, ASTROPHYSICAL JOURNAL LETTERS, Vol: 944, ISSN: 2041-8205
Farrah D, Petty S, Croker KS, et al., 2023, A Preferential Growth Channel for Supermassive Black Holes in Elliptical Galaxies at z ≲ 2, Astrophysical Journal, Vol: 943, ISSN: 0004-637X
The assembly of stellar and supermassive black hole (SMBH) mass in elliptical galaxies since z ∼ 1 can help to diagnose the origins of locally observed correlations between SMBH mass and stellar mass. We therefore construct three samples of elliptical galaxies, one at z ∼ 0 and two at 0.7 ≲ z ≲ 2.5, and quantify their relative positions in the M BH−M * plane. Using a Bayesian analysis framework, we find evidence for translational offsets in both stellar mass and SMBH mass between the local sample and both higher-redshift samples. The offsets in stellar mass are small, and consistent with measurement bias, but the offsets in SMBH mass are much larger, reaching a factor of 7 between z ∼ 1 and z ∼ 0. The magnitude of the SMBH offset may also depend on redshift, reaching a factor of ∼20 at z ∼ 2. The result is robust against variation in the high- and low-redshift samples and changes in the analysis approach. The magnitude and redshift evolution of the offset are challenging to explain in terms of selection and measurement biases. We conclude that either there is a physical mechanism that preferentially grows SMBHs in elliptical galaxies at z ≲ 2, or that selection and measurement biases are both underestimated, and depend on redshift.
Cairns J, Clements DL, Greenslade J, et al., 2023, The nature of 500 micron risers - II. Multiplicities and environments of sub-mm faint dusty star-forming galaxies, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 519, Pages: 709-728, ISSN: 0035-8711
Cramer WJ, Noble AG, Massingill K, et al., 2023, A Large-scale Kinematic Study of Molecular Gas in High-z Cluster Galaxies: Evidence for High Levels of Kinematic Asymmetry, ASTROPHYSICAL JOURNAL, Vol: 944, ISSN: 0004-637X
Farrah D, Efstathiou A, Afonso J, et al., 2023, Molecular Gas Heating, Star Formation Rate Relations, and AGN Feedback in Infrared-Luminous Galaxy Mergers, UNIVERSE, Vol: 9
Gao F, Wang L, Ramos Padilla AF, et al., 2022, Probing the megaparsec-scale environment of hyperluminous infrared galaxies at 2 < z < 4, Astronomy and Astrophysics, Vol: 668, ISSN: 0004-6361
Context. Protoclusters are progenitors of galaxy clusters and they serve as an important key in studies of how halo mass and stellar mass assemble in the early universe. Finding the signposts of such overdense regions, such as bright dusty star-forming galaxies (DSFG), is a popular method for identifying protocluster candidates. Aims. Hyperluminous infrared galaxies (HLIRGs) are ultramassive and show extreme levels of dusty star formation and black hole accretion that are expected to reside in overdense regions with massive halos. We study the megaparsec-scale environment of the largest HLIRG sample to date (526 HLIRGs over 26 deg2) and we investigate whether they are, in fact, predominantly located in overdense regions. Methods. We first explored the surface density of Herschel 250 μm sources around HLIRGs and made comparisons with the corresponding values around random positions. Then, we compared the spatial distribution of neighbors around HLIRGs with their counterparts around randomly selected galaxies using a deep IRAC-selected catalog with good-quality photometric redshifts. We also used a redshift-matched quasar sample and submillimeter galaxy (SMG) sample to validate our method, as previous clustering studies have measured the host halo masses of these populations. Finally, we adopted a friends of friends (FoF) algorithm to look for (proto)clusters hosting HLIRGs. Results. We find that HLIRGs tend to have more bright star-forming neighbors (with 250 μm flux density > 10 mJy) within a 100″ projected radius (~0.8 Mpc at 2 < z < 4), as compared to a random galaxy at a 3.7σ significance. In our 3D analysis, we find relatively weak excess of IRAC-selected sources within 3 Mpc around HLIRGs compared with random galaxy neighbors, mainly influenced by photometric redshift uncertainty and survey depth. We find a more significant difference (at a 4.7σ significance) in the number of Low Frequency Array (LOFAR)-detected neighbors in the
Symeonidis M, Maddox N, Jarvis MJ, et al., 2022, The star formation rates of QSOs, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 514, Pages: 4450-4464, ISSN: 0035-8711
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- Citations: 2
Shim H, Lee D, Kim Y, et al., 2022, Multiwavelength properties of 850-mu m selected sources from the North Ecliptic Pole SCUBA-2 survey, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 514, Pages: 2915-2935, ISSN: 0035-8711
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- Citations: 1
Greaves JS, Rimmer PB, Richards AMS, et al., 2022, Low levels of sulphur dioxide contamination of Venusian phosphine spectra, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 514, Pages: 2994-3001, ISSN: 0035-8711
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- Citations: 1
Farrah D, Efstathiou A, Afonso J, et al., 2022, Stellar and black hole assembly in z < 0.3 infrared-luminous mergers: intermittent starbursts versus super-Eddington accretion, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 513, Pages: 4770-4786, ISSN: 0035-8711
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- Citations: 1
Efstathiou A, Farrah D, Afonso J, et al., 2022, A new look at local ultraluminous infrared galaxies: the atlas and radiative transfer models of their complex physics, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 512, Pages: 5183-5213, ISSN: 0035-8711
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- Citations: 6
Clements DL, 2022, Venus, phosphine and the possibility of life, Contemporary Physics, Vol: 63, Pages: 180-199, ISSN: 0010-7514
The search for life elsewhere in the universe is one of the central aims of science in the twent-first century. While most of this work is aimed at planets orbiting other stars, the search for life in our own Solar System is an important part of this endeavour. Venus is often thought to have too harsh an environment for life, but it may have been a more hospitable place in the distant past. If life evolved there in the past then the cloud decks of Venus are the only remaining niche where life as we know it might survive today. The discovery of the molecule phosphine, PH (Formula presented.), in these clouds has reinvigorated research looking into the possibility of life in the clouds. In this review we examine the background to studies of the possibility of life on Venus, discuss the discovery of phosphine, review conflicting and confirming observations and analyses, and then look forward to future observations and space missions that will hopefully provide definitive answers as to the origin of phosphine on Venus and to the question of whether life might exist there.
Manning SM, Casey CM, Zavala JA, et al., 2022, Characterization of Two 2 mm detected Optically Obscured Dusty Star-forming Galaxies, ASTROPHYSICAL JOURNAL, Vol: 925, ISSN: 0004-637X
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- Citations: 6
Runburg J, Farrah D, Sajina A, et al., 2022, Consistent Analysis of the AGN LF in X-Ray and MIR in the XMM-LSS Field, ASTROPHYSICAL JOURNAL, Vol: 924, ISSN: 0004-637X
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- Citations: 3
Smith MWL, Eales SA, Williams TG, et al., 2021, The HASHTAG Project: The First Submillimeter Images of the Andromeda Galaxy from the Ground, ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, Vol: 257, ISSN: 0067-0049
Casey CM, Zavala JA, Manning SM, et al., 2021, Mapping Obscuration to Reionization with ALMA (MORA): 2 mm Efficiently Selects the Highest-redshift Obscured Galaxies, ASTROPHYSICAL JOURNAL, Vol: 923, ISSN: 0004-637X
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- Citations: 13
Greaves JS, Richards AMS, Bains W, et al., 2021, Phosphine gas in the cloud deck of Venus (vol 5, pg 655, 2021), Nature Astronomy, Vol: 5, Pages: 726-728, ISSN: 2397-3366
Greaves JS, Richards AMS, Bains W, et al., 2021, Reply to: No evidence of phosphine in the atmosphere of Venus from independent analyses, NATURE ASTRONOMY, Vol: 5, Pages: 636-+, ISSN: 2397-3366
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- Citations: 12
Zavala JA, Casey CM, Manning SM, et al., 2021, The Evolution of the IR Luminosity Function and Dust-obscured Star Formation over the Past 13 Billion Years, ASTROPHYSICAL JOURNAL, Vol: 909, ISSN: 0004-637X
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- Citations: 37
Lacy M, Surace JA, Farrah D, et al., 2021, A Spitzer survey of Deep Drilling Fields to be targeted by the Vera C. Rubin Observatory Legacy Survey of Space and Time, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 501, Pages: 892-910, ISSN: 0035-8711
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- Citations: 7
Riechers DA, Nayyeri H, Burgarella D, et al., 2021, Rise of the titans: gas excitation and feedback in a binary hyper-luminous dusty starburst galaxy at z~6, Astrophysical Journal Supplement Series, Vol: 907, Pages: 1-18, ISSN: 0067-0049
We report new observations toward the hyper-luminous dusty starbursting majormerger ADFS-27 (z=5.655), using ATCA and ALMA. We detect CO 2-1, 8-7, 9-8, 10-9and H2O(321-221) emission, and a P-Cygni-shaped OH+(11-01) absorption/emissionfeature. We also tentatively detect H2O(321-312) and OH+(12-01) emission andCH+(1-0) absorption. We find a total cold molecular mass of M_gas = (2.1+/-0.2)x 10^11 (alpha_CO/1.0) Msun. We also find that the excitation of thestar-forming gas is overall moderate for a z>5 dusty starburst, which isconsistent with its moderate dust temperature. A high density, high kinetictemperature gas component embedded in the gas reservoir is required to fullyexplain the CO line ladder. This component is likely associated with the"maximum starburst" nuclei in the two merging galaxies, which are separated byonly (140+/-13) km/s along the line of sight and 9.0 kpc in projection. Thekinematic structure of both components is consistent with galaxy disks, butthis interpretation remains limited by the spatial resolution of the currentdata. The OH+ features are only detected towards the northern component, whichis also the one that is more enshrouded in dust and thus remains undetected upto 1.6 um even in our sensitive new HST/WFC3 imaging. The absorption componentof the OH+ line is blueshifted and peaks near the CO and continuum emissionpeak while the emission is redshifted and peaks offset by 1.7 kpc from the COand continuum emission peak, suggesting that the gas is associated with amassive molecular outflow from the intensely star-forming nucleus that supplies125 Msun/yr of enriched gas to its halo.
Dudzeviciute U, Smail I, Swinbank AM, et al., 2021, Tracing the evolution of dust-obscured activity using sub-millimetre galaxy populations from STUDIES and AS2UDS, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 500, Pages: 942-961, ISSN: 0035-8711
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- Citations: 6
Clements DL, Serjeant S, Jin S, 2020, Explain ESA's late ditching of new space telescope, NATURE, Vol: 587, Pages: 548-548, ISSN: 0028-0836
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- Citations: 4
Shim H, Kim Y, Lee D, et al., 2020, NEPSC2, the North Ecliptic Pole SCUBA-2 survey: 850-mu m map and catalogue of 850-mu m-selected sources over 2 deg(2), MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 498, Pages: 5065-5079, ISSN: 0035-8711
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- Citations: 5
Greaves J, Richards A, Bains W, et al., 2020, Phosphine gas in the cloud decks of Venus, Nature Astronomy, Vol: 5, Pages: 655-664, ISSN: 2397-3366
Measurements of trace gases in planetary atmospheres help us explore chemical conditions different to those on Earth. Our nearest neighbour, Venus, has cloud decks that are temperate but hyperacidic. Here we report the apparent presence of phosphine (PH3) gas in Venus’s atmosphere, where any phosphorus should be in oxidized forms. Single-line millimetre-waveband spectral detections (quality up to ~15σ) from the JCMT and ALMA telescopes have no other plausible identification. Atmospheric PH3 at ~20 ppb abundance is inferred. The presence of PH3 is unexplained after exhaustive study of steady-state chemistry and photochemical pathways, with no currently known abiotic production routes in Venus’s atmosphere, clouds, surface and subsurface, or from lightning, volcanic or meteoritic delivery. PH3 could originate from unknown photochemistry or geochemistry, or, by analogy with biological production of PH3 on Earth, from the presence of life. Other PH3 spectral features should be sought, while in situ cloud and surface sampling could examine sources of this gas.
Bakx TJLC, Dannerbauer H, Frayer D, et al., 2020, IRAM 30-m-EMIR redshift search of z=3-4 lensed dusty starbursts selected from the HerBS sample, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 496, Pages: 2372-2390, ISSN: 0035-8711
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- Citations: 9
De Looze I, Lamperti I, Saintonge A, et al., 2020, JINGLE - IV. Dust, HI gas, and metal scaling laws in the local Universe, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 496, Pages: 3668-3687, ISSN: 0035-8711
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- Citations: 17
Greenslade J, Clements DL, Petitpas G, et al., 2020, The nature of 500 micron risers I: SMA observations, Monthly Notices of the Royal Astronomical Society, Vol: 496, Pages: 2315-2333, ISSN: 0035-8711
We present SMA observations at resolutions from 0.35 to 3 arcsec of a sample of 34 candidate high redshift dusty star forming galaxies (DSFGs). These sources were selected from the HerMES Herschel survey catalogues to have SEDs rising from 250 to 350 to 500 μm, a population termed 500-risers. We detect counterparts to 24 of these sources, with four having two counterparts. We conclude that the remaining ten sources that lack detected counterparts are likely to have three or more associated sources which blend together to produce the observed Herschel source. We examine the role of lensing, which is predicted to dominate the brightest (F500 > 60 mJy) half of our sample. We find that while lensing plays a role, at least 35 per cent of the bright sources are likely to be multiple sources rather than the result of lensing. At fainter fluxes we find a blending rate comparable to, or greater than, the predicted 40 per cent. We determine far-IR luminosities and star formation rates for the non-multiple sources in our sample and conclude that, in the absence of strong lensing, our 500-risers are very luminous systems with LFIR > 1013 L⊙ and star formation rates >1000 M⊙ yr−1.
Lim C-F, Chen C-C, Smail I, et al., 2020, SCUBA-2 ultra deep imaging EAO survey (STUDIES). IV. spatial clustering and halo masses of submillimeter galaxies, The Astrophysical Journal: an international review of astronomy and astronomical physics, Vol: 895, Pages: 1-18, ISSN: 0004-637X
We analyze an extremely deep 450 μm image (1σ = 0.56 mJy beam−1) of a sime300 arcmin2 area in the CANDELS/COSMOS field as part of the Sub-millimeter Common User Bolometric Array-2 Ultra Deep Imaging EAO Survey. We select a robust (signal-to-noise ratio ≥4) and flux-limited (≥4 mJy) sample of 164 submillimeter galaxies (SMGs) at 450 μm that have K-band counterparts in the COSMOS2015 catalog identified from radio or mid-infrared imaging. Utilizing this SMG sample and the 4705 K-band-selected non-SMGs that reside within the noise level ≤1 mJy beam−1 region of the 450 μm image as a training set, we develop a machine-learning classifier using K-band magnitude and color–color pairs based on the 13-band photometry available in this field. We apply the trained machine-learning classifier to the wider COSMOS field (1.6 deg2) using the same COSMOS2015 catalog and identify a sample of 6182 SMG candidates with similar colors. The number density, radio and/or mid-infrared detection rates, redshift and stellar-mass distributions, and the stacked 450 μm fluxes of these SMG candidates, from the S2COSMOS observations of the wide field, agree with the measurements made in the much smaller CANDELS field, supporting the effectiveness of the classifier. Using this SMG candidate sample, we measure the two-point autocorrelation functions from z = 3 down to z = 0.5. We find that the SMG candidates reside in halos with masses of sime(2.0 ± 0.5) × 1013 h −1 M ☉ across this redshift range. We do not find evidence of downsizing that has been suggested by other recent observational studies.
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