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相关论文: AGN dichotomy beyond radio loudness: a Gaussian Mi…

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We present a catalogue of local ($z<0.1$) galaxies that contain faint AGN. We select these objects by identifying galaxies that exhibit a significant excess in their radio luminosities, compared to what is expected from the observed levels…

星系天体物理 · 物理学 2018-06-06 E. K. Lofthouse , S. Kaviraj , D. J. B. Smith , M. J. Hardcastle

There are numerous examples of radio sources with various sizes which surprisingly exhibit very similar morphology. This observational fact helped to create a standard evolutionary model in which young and small radio-loud active galactic…

星系天体物理 · 物理学 2016-03-16 M. Kunert-Bajraszewska

We present a multi-wavelength study into the nature of faint radio sources in a deep radio image with the Giant Meterwave Radio Telescope at 612\,MHz covering 1.2 deg$^2$ of the ELAIS N1 region. We detect 2800 sources above…

星系天体物理 · 物理学 2017-04-12 E. F. Ocran , A. R. Taylor , M. Vaccari , D. A. Green

The present paper reviews our current understanding of the AGN component in sub-mJy radio fields, as it results from the exploitation of multi-frequency information available in two deep extra-galactic radio fields: the ATESP 5 GHz sample…

宇宙学与河外天体物理 · 物理学 2010-08-31 Isabella Prandoni

Radio loud active galactic nuclei (AGN) are on average 1000 times brighter in the radio band compared to radio quiet AGN. We investigate whether this radio loud/quiet dichotomy can be due to differences in the spin of the central black…

高能天体物理现象 · 物理学 2010-02-21 Alexander Tchekhovskoy , Ramesh Narayan , Jonathan C. McKinney

Over the past few years, we have been collecting data with the Nordic Optical Telescope (NOT) on the galaxy environments around active galactic nuclei (AGN). Here we present some results from a sample of 21 radio-loud and 20 radio-quiet…

天体物理学 · 物理学 2007-05-23 M. Wold , M. Lacy , P. B. Lilje , S. Serjeant

Aims. We investigate the radio loudness ($\mathcal{R}$) distribution in a large, homogeneous sample of radio galaxies. Methods. The sample is composed of galaxies from the ROGUE I/II catalogue belonging to the SDSS MGS and is divided into…

星系天体物理 · 物理学 2026-04-01 A. Wójtowicz , N. Vale Asari , Ł. Stawarz , G. Stasinska , D. Kozieł-Wierzbowska

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

Submillimeter (and in some cases millimeter) wavelength continuum measurements are presented for a sample of 40 active galactic nuclei (probably all quasars) lensed by foreground galaxies. The object of this study is to use the lensing…

天体物理学 · 物理学 2009-11-07 Richard Barvainis , Rob Ivison

Studies show that both radio jets from the active galactic nuclei (AGN) and the star formation (SF) activity in quasar host galaxies contribute to the quasar radio emission; yet their relative contributions across the population remain…

There has been a growing body of evidence to suggest that AGN activity, which is powered by mass accretion on to a supermasive black hole, could be episodic, although the range of time scales involved needs to be explored further. The…

宇宙学与河外天体物理 · 物理学 2010-02-16 D. J. Saikia , M. Jamrozy

The results of a comprehensive study of the cluster environments and black-hole masses of an optically matched sample of radio-loud and radio-quiet quasars are presented. No evidence is found for a difference in large-scale environments,…

天体物理学 · 物理学 2007-05-23 R. J. McLure , J. S. Dunlop

Understanding the interplay between black-hole accretion and star formation, and how to disentangle the two, is crucial to our understanding of galaxy formation and evolution. To investigate, we use a combination of optical and…

星系天体物理 · 物理学 2015-06-23 Sarah V. White , Matt J. Jarvis , Boris Häußler , Natasha Maddox

They are weak, they are small, and they are often overlooked, but they are numerous and an ubiquitous sign of accreting black holes: compact radio cores and jets in low-power AGN. Here I summarize our work concerning these radio cores and…

天体物理学 · 物理学 2007-05-23 Heino Falcke

We present an analysis of a large sample of AGN environments at z~1 using stacked Spitzer data at 3.6um. The sample contains type-1 and type-2 AGN in the form of quasars and radio galaxies, and spans a large range in both optical and radio…

宇宙学与河外天体物理 · 物理学 2015-05-18 J. T. Falder , J. A. Stevens , Matt J. Jarvis , M. J. Hardcastle , M. Lacy , R. J. McLure , E. Hatziminaoglou , M. J. Page , G. T. Richards

We present a brief overview of a very extensive studies of the group of active galactic nuclei (AGNs) that transitioned to radio-loud state over the past few decades. The sample consists of twelve sources, both quasars and galaxies, showing…

We explore the connection between different classes of active galactic nuclei (AGNs) and the evolution of their host galaxies, by deriving host galaxy properties, clustering, and Eddington ratios of AGNs selected in the radio, X-ray, and…

Ultra-deep radio surveys are an invaluable probe of dust-obscured star formation, but require a clear understanding of the relative contribution from radio AGN to be used to their fullest potential. We study the composition of the $\mu$Jy…

We use a recently released SDSS catalog of X-ray emitting AGNs in conjunction with the FIRST 20cm radio survey to investigate the black hole fundamental plane relationship between the 1.4GHz radio luminosity ($L_r$), 0.1-2.4 keV X-ray…

天体物理学 · 物理学 2009-11-13 Zhao-Yu Li , Xue-Bing Wu , Ran Wang

This work studies the correlation among environmental density and radio AGN presence up to $z = 2$. Using data from the photometric COSMOS survey and its radio 1.4 GHz follow-up (VLA-COSMOS), a sample of radio AGNs has been defined. The…

星系天体物理 · 物理学 2016-09-09 Nicola Malavasi , Sandro Bardelli , Paolo Ciliegi , Olivier Ilbert , Lucia Pozzetti , Elena Zucca