English
Related papers

Related papers: The evolution of radio sources in the UKIDSS-DXS X…

200 papers

The quasar sample selected by cross-correlating the FIRST and the 2dF Quasar Redshift Surveys allows us to explore, for the first time, the faint end of the radio and optical luminosity functions up to z = 2.2. We find indications (~3…

Astrophysics · Physics 2009-11-10 M. Cirasuolo , M. Magliocchetti , A. Celotti

We present Very Large Array (VLA) observations at 1.4 GHz and 5 GHz of a sample of 12 Quasi-stellar Objects (QSOs) at z = 3.99 to 4.46. The sources were selected as the brightest sources at 250 GHz from the recent survey of Omont et al.…

Astrophysics · Physics 2009-11-06 C. L. Carilli , F. Bertoldi , A. Omont , P. Cox , R. G. McMahon , K. G. Isaak

With the advent of deep, all-sky radio surveys, the need for ancillary data to make the most of the new, high-quality radio data from surveys like the Evolutionary Map of the Universe (EMU), GLEAM-X, VLASS and LoTSS is growing rapidly.…

Instrumentation and Methods for Astrophysics · Physics 2023-07-13 Kieran J. Luken , Ray P. Norris , X. Rosalind Wang , Laurence A. F. Park , Ying Guo , Miroslav D. Filipovic

We have compiled a sample of 234 ultra-steep-spectrum(USS)-selected radio sources in order to find high-redshift radio galaxies (HzRGs). The sample is in the southern sky at -40 deg < DEC < -30 deg which is the overlap region of the 408-MHz…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 J. J. Bryant , H. M. Johnston , J. W. Broderick , R. W. Hunstead , C. De Breuck , B. M. Gaensler

Ultra Steep Spectrum (USS) radio sources are one of the efficient tracers of powerful High-z Radio Galaxies (HzRGs). In contrast to searches for powerful HzRGs from radio surveys of moderate depths, fainter USS samples derived from deeper…

We present the results of 5-GHz observations with the VLA A-array of a sample of candidate Compact Steep Spectrum sources (CSSs) selected from the S4 survey. We also estimate the symmetry parameters of high-luminosity CSSs selected from…

Astrophysics · Physics 2009-10-31 D. J. Saikia , S. Jeyakumar , C. J. Salter , P. Thomasson , R. E. Spencer , F. Mantovani

Feedback from low-excitation radio galaxies (LERGs) plays a key role in the lifecycle of massive galaxies in the local Universe; their evolution, and the impact of these active galactic nuclei on early galaxy evolution, however, remain…

We have made a radio survey--the Australia Telescope Low Brightness Survey (ATLBS)--of 8.4 square degrees sky area, using the Australia Telescope Compact Array in the 20-cm band, in an observing mode designed to provide wide-field images…

Astrophysics · Physics 2009-06-23 Ravi Subrahmanyan , R. D. Ekers , Lakshmi Saripalli , E. M. Sadler

The recently-finished Edinburgh UVX quasar survey at B < 18 is used together with other complete samples to estimate the shape and evolution of the optical luminosity function in the redshift range 0.3 < z < 2.2. There is a significantly…

Astrophysics · Physics 2009-07-28 Pippa Goldschmidt , Lance Miller

We investigate the relationship between faint X-ray and 1.4 GHz radio source populations detected within 3' of the Hubble Deep Field North using the 1 Ms Chandra and 40 uJy VLA surveys. Within this region, we find that ~42% of the 62 X-ray…

We use redshift observations of two deep 1.4GHz fields to probe the evolution of the bright end of the radio galaxy luminosity function to z=1.5. We show that the number of galaxies with radio power that would correspond locally to an…

Astrophysics · Physics 2009-11-10 L. L. Cowie , A. J. Barger , E. B. Fomalont , P. Capak

We have obtained spectroscopic redshifts using the Keck-I telescope for a sample of 73 submillimeter (submm) galaxies for which precise positions are available. The galaxies lie at redshifts out to z=3.6, with a median redshift of 2.2. The…

Astrophysics · Physics 2009-07-09 S. C. Chapman , A. W. Blain , Ian Smail , R. J. Ivison

The Combined EIS-NVSS Survey Of Radio Sources (CENSORS) is a 1.4 GHz radio survey selected from the NRAO VLA Sky Survey (NVSS) and complete to a flux-density of 7.2mJy. It targets the ESO Imaging Survey (EIS) Patch D, which is a 3 by 2…

Astrophysics · Physics 2009-11-11 M. H. Brookes , P. N. Best , R. Rengelink , H. J. A. Rottgering

We determine the radio and optical luminosity evolutions and the true distribution of the radio loudness parameter R, defined as the ratio of the radio to optical luminosity, for a set of more than 5000 quasars combining SDSS optical and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 J. Singal , V. Petrosian , L. Stawarz , A. Lawrence

[Abridged] We present the rest-frame Js-band and Ks-band luminosity function of a sample of about 300 galaxies selected in the HDF-S at Ks<23 (Vega). We use calibrated photometric redshift together with spectroscopic redshift for 25% of the…

We describe some of the first X-ray detections of groups of galaxies at high redshifts (z~0.4), based on the UK deep X-ray survey of McHardy et al (1998). Combined with other deep ROSAT X-ray surveys with nearly complete optical…

Astrophysics · Physics 2009-11-07 L. R. Jones , I. McHardy , A. Newsam , K. Mason

We combine the LOw-Frequency ARray (LOFAR) Two-metre Sky Survey (LoTSS) second data release (DR2) catalogue with gravitational lensing maps from the Cosmic Microwave Background (CMB) to place constraints on the bias evolution of LoTSS radio…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-17 S. J. Nakoneczny , D. Alonso , M. Bilicki , D. J. Schwarz , C. L. Hale , A. Pollo , C. Heneka , P. Tiwari , J. Zheng , M. Brüggen , M. J. Jarvis , T. W. Shimwell

We have utilized the largest sample of $\gamma$-ray selected Fermi flat-spectrum radio quasars (FSRQs) ever used (519 sources) to construct the luminosity function and its evolution through the cosmic history. In addition to spanning large…

High Energy Astrophysical Phenomena · Physics 2025-12-02 Garima Rajguru , Lea Marcotulli , Marco Ajello , Mattia Di Mauro , Meg Urry

It has been claimed by Taylor et al. that the low-redshift end of the K-z relation for radio galaxies is too bright by about half a magnitude due to contributions from the obscured quasar nuclei. Such a result has major implications for the…

Astrophysics · Physics 2009-10-31 Chris Simpson , Martin Ward , J. V. Wall

Star formation history in galaxies is strongly correlated to their present-day colors and the Hubble sequence can be considered as a sequence of different star formation history. Therefore we can model the cosmic star formation history…

Astrophysics · Physics 2007-05-23 Tomonori Totani
‹ Prev 1 4 5 6 7 8 10 Next ›