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相关论文: The VVDS type-1 AGN sample: The faint end of the l…

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In this proceedings paper, I overview the current status of the X-ray luminosity function of AGNs in the soft (0.5-2 keV) band, extended using XMM-Newton and Chandra survey data. We found that the number density of low luminosity AGNs peaks…

天体物理学 · 物理学 2007-05-23 Takamitsu Miyaji

This study explores the space density and properties of active galaxies to z=0.8. We have investigated the frequency and nature of unresolved nuclei in galaxies at moderate redshift as indicators of nuclear activity such as Active Galactic…

天体物理学 · 物理学 2009-10-31 Vicki L. Sarajedini , Richard F. Green , Richard E. Griffiths , Kavan Ratnatunga

We model the evolution of active galactic nuclei by constructing their radio luminosity functions. We use a set of surveys of varying area and depth, namely the deep COSMOS survey of $1,916$ AGN sources, the wide shallow 3CRR, 7C and 6CE…

星系天体物理 · 物理学 2023-12-25 B. Šlaus , V. Smolcic , Ž. Ivezic , S. Fotopoulou , C. J. Willott , P. Pendo , C. Vignali , L. Chiappetti , M. Pierre

We present the estimate of the evolution of type 1 AGNs in the hard (2-10 keV) X-rays drawn from the HELLAS survey, and in the IR (15um) obtained from the ELAIS survey. We find that the local luminosity function (LF) of AGN1 in the 2-10 keV…

The fraction of AGN luminosity obscured by dust and re-emitted in the mid-IR is critical for understanding AGN evolution, unification, and parsec-scale AGN physics. For unobscured (Type-1) AGN, where we have a direct view of the accretion…

宇宙学与河外天体物理 · 物理学 2015-06-17 E. Lusso , J. F. Hennawi , A. Comastri , G. Zamorani , G. T. Richards , C. Vignali , E. Treister , K. Schawinski , M. Salvato , R. Gilli

We present the measurement of the line-of-sight extinction of the dusty torus for a large number of obscured active galactic nuclei (AGNs) based on the reddening of the colour of the variable flux component in near-infrared (NIR)…

The high angular resolution and sensitivity of the Chandra X-ray Observatory has yielded large numbers of faint X-ray sources with measured redshifts in the soft (0.5-2 keV) and hard (2-8 keV) energy bands. Many of these sources show few…

天体物理学 · 物理学 2009-11-07 L. L. Cowie , A. J. Barger , M. W. Bautz , W. N. Brandt , G. P. Garmire

We aim to constrain the evolution of AGN as a function of obscuration using an X-ray selected sample of $\sim2000$ AGN from a multi-tiered survey including the CDFS, AEGIS-XD, COSMOS and XMM-XXL fields. The spectra of individual X-ray…

We present a detailed analysis of the most luminous and obscured Active Galactic Nuclei (AGNs) detected in the ultra-hard X-ray band (14-195 keV) by Swift/BAT. Our sample comprises 21 X-ray luminous (log $L_X/{\rm erg\,s^{-1}}>44.6$, 2-10…

We used data from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) to study the incidence of AGN in continuum-selected galaxies at $z\sim3$. From optical and infrared imaging in the 24 deg$^{2}$ Spitzer HETDEX Exploratory Large…

We describe the completed VIMOS VLT Deep Survey, and the final data release of 35016 galaxies and type-I AGN with measured spectroscopic redshifts up to redshift z~6.7, in areas 0.142 to 8.7 square degrees, and volumes from 0.5x10^6 to…

We investigate faint radio emission from low- to high-luminosity Active Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey (SDSS). Their radio properties are inferred by co-adding large ensembles of radio image cut-outs from…

天体物理学 · 物理学 2008-11-26 W. H. de Vries , J. A. Hodge , R. H. Becker , R. L. White , D. J. Helfand

This paper presents a new grid-based method for investigating the evolution of the steep-spectrum radio luminosity function, with the aim of quantifying the high-redshift cut-off suggested by previous work. To achieve this, the Combined…

宇宙学与河外天体物理 · 物理学 2015-05-28 E. E. Rigby , P. N. Best , M. H. Brookes , J. A. Peacock , J. S. Dunlop , H. J. A. Röttgering , J. V. Wall , L. Ker

We employ the Chandra Multiwavelength Project (ChaMP) and the Sloan Digital Sky Survey (SDSS) to study the fraction of X-ray-active galaxies in the field out to z = 0.7. We utilize spectroscopic redshifts from SDSS and ChaMP, as well as…

高能天体物理现象 · 物理学 2015-05-18 Daryl Haggard , Paul J. Green , Scott F. Anderson , Anca Constantin , Tom L. Aldcroft , Dong-Woo Kim , Wayne A. Barkhouse

We measure the rest-frame UV luminosity function (LF) at $z \sim 4$ self-consistently over a wide range in absolute magnitude ($-27 \lesssim M_{\rm UV} \lesssim -20$). The LF is measured with 46,904 sources selected using a photometric…

星系天体物理 · 物理学 2020-03-18 N. J. Adams , R. A. A. Bowler , M. J. Jarvis , B. Häußler , R. J. McLure , A. Bunker , J. S. Dunlop , A. Verma

We present a joint analysis of the rest-frame ultraviolet (UV) luminosity functions of continuum-selected star-forming galaxies and galaxies dominated by active galactic nuclei (AGNs) at $z \sim$ 4. These 3,740 $z \sim$ 4 galaxies are…

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

We present measurements of the rest-frame ultraviolet luminosity function at redshifts $z=3$, $z=4$ and $z=5$, using 96894, 38655 and 7571 sources respectively to map the transition between AGN and galaxy-dominated ultraviolet emission…

星系天体物理 · 物理学 2023-05-16 N. J. Adams , R. A. A. Bowler , M. J. Jarvis , R. G. Varadaraj , B. Häußler

We present our sixth work in a series dedicated to variability studies of active galactic nuclei (AGN) based on the survey of the COSMOS field by the VLT Survey Telescope (VST). Its 54 r-band visits over 3.3 yr and single-visit depth of…

Recent deep surveys have unravelled a population of faint active galactic nuclei (AGN) in the high redshift Universe, leading to various discussions on their nature and their role during the Epoch of Reionization. We use cosmological…

星系天体物理 · 物理学 2020-04-29 Maxime Trebitsch , Marta Volonteri , Yohan Dubois