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相关论文: Cosmological Studies from Radio Source Samples

200 篇论文

We present a new evolutionary model that describes the population properties of radio sources at frequencies <5 GHz, thus complementing the De Zotti et al. (2005) model, holding at higher frequencies. We find that simple analytic luminosity…

宇宙学与河外天体物理 · 物理学 2015-05-14 Marcella Massardi , Anna Bonaldi , Mattia Negrello , Sara Ricciardi , Alvise Raccanelli , Gianfranco De Zotti

We have explored, in the general framework of the ``young source'' scenario, evolutionary models for GHz Peaked Spectrum (GPS) galaxies and quasars which reproduce the observed counts, redshift and peak frequency distributions of currently…

天体物理学 · 物理学 2007-05-23 G. De Zotti , G. L. Granato , L. Silva , D. Maino , L. Danese

We have observed the faintest sample of Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources to date, using the Australia Telescope Compact Array. We test the hypothesis that GPS and CSS sources are the youngest radio…

星系天体物理 · 物理学 2016-12-07 J. D. Collier , R. P. Norris , M. D. Filipović , N. F. H. Tothill

It has been speculated that low luminosity radio-loud AGN have the potential to serve as an important source of AGN feedback, and may be responsible for suppressing star-formation activity in massive elliptical galaxies at late times. As…

宇宙学与河外天体物理 · 物理学 2015-06-17 K. McAlpine , M. J. Jarvis , D. G. Bonfield

We have recently used the Faint Images of the Radio Sky at Twenty-centimeters (FIRST) survey to show that red quasars have fundamentally different radio properties to typical blue quasars: a significant (factor $\sim3$) enhancement in the…

The Gigahertz Peaked Spectrum (GPS) sources, Compact Steep Spectrum (CSS) radio sources, and High Frequency Peakers (HFP) radio sources are thought to be young radio AGNs, at the early stage of AGN evolution. We investigated the optical…

星系天体物理 · 物理学 2019-12-11 Mai Liao , Minfeng Gu

We match quasars discovered in a multi-color survey centered on the northern Hubble Deep Field (HDF) with radio sources from an ultra-deep radio survey. Although 3 out of 12 quasars are detected at a level below 0.2 mJy at 1.4 GHz, all of…

天体物理学 · 物理学 2009-10-31 C. Impey , C. Petry

The radio-loud/radio-quiet (RL/RQ) dichotomy in quasars is still an open question. Although it is thought that accretion onto supermassive black holes in the centre the host galaxies of quasars is responsible for some radio continuum…

We combine Chandra and XMM-Newton X-ray data from our previous papers with new X-ray observations and with Spitzer mid-infrared data in order to study the nature of the nuclei of radio galaxies and radio-loud quasars with z<1.0 from the…

星系天体物理 · 物理学 2015-05-13 M. J. Hardcastle , D. A. Evans , J. H. Croston

Published data from long-term observations of a strip of sky at declination +5 degrees carried out at 7.6 cm on the RATAN-600 radio telescope are used to estimate some statistical properties of radio sources. Limits on the sensitivity of…

宇宙学与河外天体物理 · 物理学 2012-05-24 Yu. N. Parijskij , N. S. Soboleva , A. V. Temirova , N. N. Bursov , O. P. Zhelenkova

We discuss how the interaction between the electrons in a relativistic jet and the Cosmic Microwave Background (CMB) affects the observable properties of radio-loud AGN at early epochs. At high z the magnetic energy density in the radio…

宇宙学与河外天体物理 · 物理学 2015-06-18 G. Ghisellini , A. Celotti , F. Tavecchio , F. Haardt , T. Sbarrato

Radio mode feedback, in which most of the energy of an active galactic nucleus (AGN) is released in a kinetic form via radio-emitting jets, is thought to play an important role in the maintenance of massive galaxies in the present-day…

星系天体物理 · 物理学 2015-06-22 W. Ishibashi , M. W. Auger , D. Zhang , A. C. Fabian

We study the Extended Chandra Deep Field South (E-CDFS) Very Large Array sample, which reaches a flux density limit at 1.4 GHz of 32.5 microJy at the field centre and redshift ~ 4, and covers ~ 0.3 deg^2. Number counts are presented for the…

星系天体物理 · 物理学 2015-08-06 P. Padovani , M. Bonzini , K. I. Kellermann , N. Miller , V. Mainieri , P. Tozzi

In order to find more examples of the elusive high-redshift molecular absorbers, we have embarked on a systematic discovery program for highly obscured, radio-loud "invisible AGN" using the VLA Faint Images of the Radio Sky at Twenty…

宇宙学与河外天体物理 · 物理学 2015-06-11 T. Yan , J. T. Stocke , J. Darling , F. Hearty

In this paper I review the results of our ongoing project to investigate the coupling between accretion disk and radio jet in galactic nuclei and stellar mass black holes. We find a good correlation between the UV bump luminosity and the…

天体物理学 · 物理学 2015-06-24 Heino Falcke

A complete, flux density limited sample of 96 faint ($> 0.5$ mJy) radio sources is selected from the 10C survey at 15.7 GHz in the Lockman Hole. We have matched this sample to a range of multi-wavelength catalogues, including SERVS, SWIRE,…

星系天体物理 · 物理学 2015-09-30 I. H. Whittam , J. M. Riley , D. A. Green , M. J. Jarvis , M. Vaccari

We have determined the central velocity dispersion and surface brightness profiles for a sample of powerful radio galaxies in the redshift range 0.06<z<0.31, which were selected on the basis of their young radio source. The optical hosts…

天体物理学 · 物理学 2009-11-07 I. A. G. Snellen , M. D. Lehnert , M. N. Bremer , R. T. Schilizzi

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…

天体物理学 · 物理学 2009-11-10 M. Cirasuolo , M. Magliocchetti , A. Celotti

We present an analysis of four complete samples of radio-loud AGN (3CRR, 2Jy, 6CE and 7CE) using near- and mid-IR data taken by the Wide-Field Infrared Survey Explorer (WISE). The combined sample consists of 79 quasars and 273 radio…

宇宙学与河外天体物理 · 物理学 2013-11-25 G. Gurkan , M. J. Hardcastle , M. J. Jarvis

This paper presents the first high-resolution and high-sensitivity study of the radio properties of optically selected type~2 quasars. We used the Very Large Array at 8.4 GHz to observe 59 sources drawn from the Sloan Digital Sky Survey…

宇宙学与河外天体物理 · 物理学 2015-05-14 Dharam Vir Lal , Luis C. Ho