Publications
471 results found
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
Observations have found black holes spanning 10 orders of magnitude in mass across most of cosmic history. The Kerr black hole solution is, however, provisional as its behavior at infinity is incompatible with an expanding universe. Black hole models with realistic behavior at infinity predict that the gravitating mass of a black hole can increase with the expansion of the universe independently of accretion or mergers, in a manner that depends on the black hole’s interior solution. We test this prediction by considering the growth of supermassive black holes in elliptical galaxies over 0 < z ≲ 2.5. We find evidence for cosmologically coupled mass growth among these black holes, with zero cosmological coupling excluded at 99.98% confidence. The redshift dependence of the mass growth implies that, at z ≲ 7, black holes contribute an effectively constant cosmological energy density to Friedmann’s equations. The continuity equation then requires that black holes contribute cosmologically as vacuum energy. We further show that black hole production from the cosmic star formation history gives the value of ΩΛ measured by Planck while being consistent with constraints from massive compact halo objects. We thus propose that stellar remnant black holes are the astrophysical origin of dark energy, explaining the onset of accelerating expansion at z ∼ 0.7.
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
We investigate the resolved kinematics of the molecular gas, as traced by the Atacama Large Millimeter/submillimeter Array in CO (2−1), of 25 cluster member galaxies across three different clusters at a redshift of z ∼ 1.6. This is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at this redshift. By separately estimating the rotation curve of the approaching and receding sides of each galaxy via kinematic modeling, we quantify the difference in total circular velocity to characterize the overall kinematic asymmetry of each galaxy. 3/14 of the galaxies in our sample that we are able to model have similar degrees of asymmetry as that observed in galaxies in the field at similar redshift based on observations of mainly ionized gas. However, this leaves 11/14 galaxies in our sample with significantly higher asymmetry, and some of these galaxies have degrees of asymmetry of up to ∼50 times higher than field galaxies observed at similar redshift. Some of these extreme cases also have one-sided tail-like morphology seen in the molecular gas, supporting a scenario of tidal and/or ram pressure interaction. Such stark differences in the kinematic asymmetry in clusters versus the field suggest the evolutionary influence of dense environments, established as being a major driver of galaxy evolution at low redshift, is also active in the high-redshift universe.
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
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.
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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- Citations: 3
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
- Author Web Link
- Cite
- Citations: 6
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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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
- Author Web Link
- Cite
- 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.
Cheng T, Clements DL, Greenslade J, et al., 2020, SCUBA-2 overdensities associated with candidate protoclusters selected from Planck data, Monthly Notices of the Royal Astronomical Society, Vol: 494, Pages: 5985-5991, ISSN: 0035-8711
We measure the 850-μm source densities of 46 candidate protoclusters selected from the Planck high-z catalogue (PHz) and the Planck Catalogue of Compact Sources (PCCS) that were followed up with Herschel-SPIRE and SCUBA-2. This paper aims to search for overdensities of 850-μm sources in order to select the fields that are most likely to be genuine protoclusters. Of the 46 candidate protoclusters, 25 have significant overdensities (>5 times the field counts), 11 have intermediate overdensities (3–5 times the field counts), and 10 have no overdensity (<3 times the field counts) of 850-μm sources. We find that the enhanced number densities are unlikely to be the result of sample variance. Compared with the number counts of another sample selected from Planck’s compact source catalogues, this [PHz + PCCS]-selected sample has a higher fraction of candidate protoclusters with significant overdensities, though both samples show overdensities of 850-μm sources above intermediate level. Based on the estimated star formation rate densities (SFRDs), we suggest that both samples can efficiently select protoclusters with starbursting galaxies near the redshift at which the global field SFRD peaks (2 < z < 3). Based on the confirmation of overdensities found here, future follow-up observations on other PHz targets may greatly increase the number of genuine dusty star-forming galaxy-rich clusters/protoclusters.
Bakx TJLC, Eales SA, Negrello M, et al., 2020, The Herschel Bright Sources (HerBS): sample definition and SCUBA-2 observations (vol 473, pg 1751, 2018), MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 494, Pages: 10-16, ISSN: 0035-8711
- Author Web Link
- Cite
- Citations: 7
Lim C-F, Wang W-H, Smail I, et al., 2020, SCUBA-2 ultra deep imaging EAO survey (studies). III. multiwavelength properties, luminosity functions, and preliminary source catalog of 450 mu m selected galaxies, The Astrophysical Journal: an international review of astronomy and astronomical physics, Vol: 889, Pages: 1-33, ISSN: 0004-637X
We construct a SCUBA-2 450 μm map in the COSMOS field that covers an area of 300 arcmin2 and reaches a 1σ noise level of 0.65 mJy in the deepest region. We extract 256 sources detected at 450 μm with signal-to-noise ratios >4.0 and analyze the physical properties of their multiwavelength counterparts. We find that most of the sources are at z lesssim 3, with a median of $z={1.79}_{-0.15}^{+0.03} \% $. About ${35}_{-25}^{+32} \% $ of our sources are classified as starburst galaxies based on their total star formation rates (SFRs) and stellar masses (M *). By fitting the far-infrared spectral energy distributions, we find that our 450 μm selected sample has a wide range of dust temperatures (20 K lesssim T d lesssim 60 K), with a median of ${T}_{{\rm{d}}}={38.3}_{-0.9}^{+0.4}$ K. We do not find a redshift evolution in dust temperature for sources with ${L}_{\mathrm{IR}}\gt {10}^{12}\,{L}_{\odot }$ at z < 3. However, we find a moderate correlation where the dust temperature increases with the deviation from the SFR–M * relation. The increase in dust temperature also correlates with optical morphology, which is consistent with merger-triggered starbursts in submillimeter galaxies. Our galaxies do not show the tight IRX–β UV correlation that has been observed in the local universe. We construct the infrared luminosity functions of our 450 μm sources and measure their comoving SFR densities (SFRDs). The contribution of the ${L}_{\mathrm{IR}}\gt {10}^{12}\,{L}_{\odot }$ population to the SFRD rises dramatically from z = 0 to 2 (∝(1 + z)3.9±1.1) and dominates the total SFRD at z gsim 2.
Duivenvoorden S, Oliver S, Bethermin M, et al., 2020, Have we seen all the galaxies that comprise the cosmic infrared background at 250 mu m <= lambda <= 500 mu m?, Monthly Notices of the Royal Astronomical Society, Vol: 491, Pages: 1355-1368, ISSN: 0035-8711
The cosmic infrared background (CIB) provides a fundamental observational constraint on the star formation history of galaxies over cosmic history. We estimate the contribution to the CIB from catalogued galaxies in the COSMOS field by using a novel map fitting technique on the Herschel SPIRE maps. Prior galaxy positions are obtained using detections over a large range in wavelengths in the Ks–3 GHz range. Our method simultaneously fits the galaxies, the system foreground, and the leakage of flux from galaxies located in masked areas and corrects for an ‘overfitting’ effect not previously accounted for in stacking methods. We explore the contribution to the CIB as a function of galaxy survey wavelength and depth. We find high contributions to the CIB with the deep r (mAB ≤ 26.5), Ks (mAB ≤ 24.0), and 3.6 μm (mAB ≤ 25.5) catalogues. We combine these three deep catalogues and find a total CIB contributions of 10.5 ± 1.6, 6.7 ± 1.5, and 3.1 ± 0.7 nWm−2 sr−1 at 250, 350, and 500 μm, respectively. Our CIB estimates are consistent with recent phenomenological models, prior based SPIRE number counts and with (though more precise than) the diffuse total measured by FIRAS. Our results raise the interesting prospect that the CIB contribution at λ≤500μm from known galaxies has converged. Future large-area surveys like those with the Large Synoptic Survey Telescope are therefore likely to resolve a substantial fraction of the population responsible for the CIB at 250 μm ≤ λ ≤ 500 μm.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.