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Deep Extragalactic VIsible Legacy Survey (DEVILS): First Data Release Covering The D10 (COSMOS) Region
Authors:
L. J. M. Davies,
M. Bravo,
R. H. W. Cook,
A. Hashemizadeh,
J. E. Thorne,
S. Bellstedt,
S. P. Driver,
A. S. G. Robotham,
S. Koushan,
N. Adams,
S. Huynh,
E. J. A. Mannering,
J. Tocknell,
M. J. I. Brown,
J. Bland-Hawthorn,
L. Cortese,
B. Catinella,
M. Meyer,
S. Phillipps,
M. Siudek,
C. Wolf
Abstract:
The Deep Extragalactic VIsible Legacy Survey (DEVILS) is a deep, high-completeness multi-wavelength survey based around spectroscopic observations using the Anglo-Australian Telescope's AAOmega spectrograph. The survey covers $\sim4.5$deg$^{2}$ over three extragalactic fields to Y$_{AB}<21.2$mag and probes sources at $0<z<1.2$, with a median redshift of $z=0.53$. Here we describe the DEVILS spectr…
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The Deep Extragalactic VIsible Legacy Survey (DEVILS) is a deep, high-completeness multi-wavelength survey based around spectroscopic observations using the Anglo-Australian Telescope's AAOmega spectrograph. The survey covers $\sim4.5$deg$^{2}$ over three extragalactic fields to Y$_{AB}<21.2$mag and probes sources at $0<z<1.2$, with a median redshift of $z=0.53$. Here we describe the DEVILS spectroscopic observations, data reduction and redshift analysis. We then describe and release to the community all DEVILS data in the 10h (D10, COSMOS) region including: i) catalogues of redshifts, photometry, SED fitting for physical properties, visual morphologies, structural decompositions and group environments/halo masses, ii) matched imaging in 28 bands from x-rays to radio continuum, and iii) reduced 1D spectra. All data are made publicly available through Data Central. Within D10 we obtain 5,442 new high-quality spectroscopic redshifts. When combined with existing, lower-quality, redshift information ($i.e.$ photometric redshifts) this is increased to 7,946. Of these, 3,122 have a spectroscopic redshift from another source (many that was not available at the time of the DEVILS observations). As such, DEVILS provides new unique high-quality spectroscopic redshifts for 4,824 faint sources in COSMOS. This increases the spectroscopic completeness at Y-mag$\sim$21 from $\sim$50% in other samples to $\sim$90% in DEVILS. Finally, we show the power of this dataset by exploring the suppression of star formation in over-dense environments, split by morphology and stellar mass, and highlighting the ubiquitous nature of environmental quenching.
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Submitted 25 November, 2025;
originally announced November 2025.
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Identifying clustering at high redshift through actively star-forming galaxies
Authors:
L. J. M. Davies,
M. N. Bremer,
E. R. Stanway,
K. Husband,
M. D. Lehnert,
E. J. A. Mannering
Abstract:
Identifying galaxy clustering at high redshift (i.e. z > 1) is essential to our understanding of the current cosmological model. However, at increasing redshift, clusters evolve considerably in star-formation activity and so are less likely to be identified using the widely-used red sequence method. Here we assess the viability of instead identifying high redshift clustering using actively star-fo…
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Identifying galaxy clustering at high redshift (i.e. z > 1) is essential to our understanding of the current cosmological model. However, at increasing redshift, clusters evolve considerably in star-formation activity and so are less likely to be identified using the widely-used red sequence method. Here we assess the viability of instead identifying high redshift clustering using actively star-forming galaxies (SMGs associated with over-densities of BzKs/LBGs). We perform both a 2- and 3-D clustering analysis to determine whether or not true (3D) clustering can be identified where only 2D data are available. As expected, we find that 2D clustering signals are weak at best and inferred results are method dependant. In our 3D analysis, we identify 12 SMGs associated with an over-density of galaxies coincident both spatially and in redshift - just 8% of SMGs with known redshifts in our sample. Where an SMG in our target fields lacks a known redshift, their sightline is no more likely to display clustering than blank sky fields; prior redshift information for the SMG is required to identify a true clustering signal. We find that the strength of clustering in the volume around typical SMGs, while identifiable, is not exceptional. However, we identify a small number of highly clustered regions, all associated with an SMG. The most notable of these, surrounding LESSJ033336.8-274401, potentially contains an SMG, a QSO and 36 star-forming galaxies (a > 20sig over-density) all at z~1.8. This region is highly likely to represent an actively star-forming cluster and illustrates the success of using star-forming galaxies to select sites of early clustering. Given the increasing number of deep fields with large volumes of spectroscopy, or high quality and reliable photometric redshifts, this opens a new avenue for cluster identification in the young Universe.
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Submitted 11 December, 2013;
originally announced December 2013.
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Galaxy gas ejection in radio galaxies: the case of 3C 35
Authors:
Elizabeth J. A. Mannering,
Diana M. Worrall,
Mark Birkinshaw
Abstract:
We report results from XMM-Newton and Chandra observations of the nearby (z = 0.067) giant radio galaxy 3C 35. We find evidence for an X-ray emitting gas belt, orthogonal to and lying between the lobes of 3C 35, which we interpret as fossil-group gas driven outwards by the expanding radio lobes. We also detect weak emission from a second, more extended group-type environment, as well as inverse-Co…
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We report results from XMM-Newton and Chandra observations of the nearby (z = 0.067) giant radio galaxy 3C 35. We find evidence for an X-ray emitting gas belt, orthogonal to and lying between the lobes of 3C 35, which we interpret as fossil-group gas driven outwards by the expanding radio lobes. We also detect weak emission from a second, more extended group-type environment, as well as inverse-Compton X-ray emission from the radio lobes. The morphological structure of the radio lobes and gas belt point to co-evolution. Furthermore, the radio source is powerful enough to eject galaxy-scale gas out to distances of 100kpc, and the ages of the two features are comparable (tsynch~140Myr, tbelt~80 Myr). The destruction of 3C 35's atmosphere may offer clues as to how fossil systems are regulated: radio galaxies need to be of power comparable to 3C 35 to displace and regulate fossil-group gas. We discuss the implications of the gas belt in 3C 35 in terms of AGN fuelling and feedback.
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Submitted 6 February, 2013;
originally announced February 2013.
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The host galaxies of radio-loud AGN: colour structure
Authors:
Elizabeth J. A. Mannering,
Diana M. Worrall,
Mark Birkinshaw
Abstract:
We construct a sample of 3,516 radio-loud host galaxies of active galactic nuclei (AGN) from the optical Sloan Digital Sky Survey (SDSS) and Faint Images of the Radio Sky at Twenty cm (FIRST). These have 1.4 GHz luminosities in the range 10E23-1025 WHz^{-1}, span redshifts 0.02<z<0.18, are brighter than r*_{petro}<17.77 mag and are constrained to `early-type' morphology in colour space (u*-r*>2.22…
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We construct a sample of 3,516 radio-loud host galaxies of active galactic nuclei (AGN) from the optical Sloan Digital Sky Survey (SDSS) and Faint Images of the Radio Sky at Twenty cm (FIRST). These have 1.4 GHz luminosities in the range 10E23-1025 WHz^{-1}, span redshifts 0.02<z<0.18, are brighter than r*_{petro}<17.77 mag and are constrained to `early-type' morphology in colour space (u*-r*>2.22 mag). Optical emission line ratios (at >3 sigma) are used to remove type 1 AGN and star-forming galaxies from the radio sample using BPT diagnostics. For comparison, we select a sample of 35,160 radio-quiet galaxies with the same r*-band magnitude-redshift distribution as the radio sample. We also create comparison radio and control samples derived by adding the NRAO VLA Sky Survey (NVSS) to quantify the effect of completeness on our results.
We investigate the effective radii of the surface brightness profiles in the SDSS r and u bands in order to quantify any excess of blue colour in the inner region of radio galaxies. We define a ratio R=r_{e}(r)/r_{e}(u) and use maximum likelihood analysis to compare the average value of R and its intrinsic dispersion between both samples. R is larger for the radio-loud AGN sample as compared to its control counterpart, and we conclude that the two samples are not drawn from the same population at >99% significance. Given that star formation proceeds over a longer time than radio activity, the difference suggests that a subset of galaxies has the predisposition to become radio loud. We discuss host galaxy features that cause the presence of a radio-loud AGN to increase the scale size of a galaxy in red relative to blue light, including excess central blue emission, point-like blue emission from the AGN itself, and/or diffuse red emission. We favour an explanation that arises from the stellar rather than the AGN light.
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Submitted 27 June, 2011;
originally announced June 2011.