中文
相关论文

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

200 篇论文

In deep X-ray surveys, active galactic nuclei (AGNs) with a broad range of luminosities have been identified. However, cosmologically distant low-luminosity AGN (LLAGN, $L_{\mathrm{X}} \lesssim 10^{42}$ erg s$^{-1}$) identification still…

It is a widespread opinion that hydrogen reionization is mainly driven by primeval star-forming galaxies, with a minor role of high-z active galactic nuclei. Recent observations, however, challenge this notion, indicating a number of issues…

星系天体物理 · 物理学 2020-07-15 A. Grazian , E. Giallongo , F. Fiore , K. Boutsia , F. Civano , S. Cristiani , G. Cupani , M. Dickinson , F. Fontanot , N. Menci , M. Romano

AIMS. This work addresses the AGN IR-selection dependency on intrinsic source luminosity and obscuration, in order to identify and charaterise biases which could affect conclusions in studies. METHODS. We study IR-selected AGN in the…

星系天体物理 · 物理学 2015-06-18 Hugo Messias , Jose M. Afonso , Mara Salvato , Bahram Mobasher , Andrew M. Hopkins

We derive the Ultra-Violet (UV) luminosity function (LF) of star-forming galaxies in the redshift range $z = 0.6 - 1.2$, in the rest-frame far-UV ($1500$ \r{A}) wavelength. For this work, we are in particular interested in the bright end of…

星系天体物理 · 物理学 2024-05-16 M. Sharma , M. J. Page , I. Ferreras , A. A. Breeveld

We report a sizable class of type 1 active galactic nuclei (AGNs) with unusually weak near-infrared (1-3{\mu}m) emission in the XMM-COSMOS type 1 AGN sample. The fraction of these "hot-dust-poor" AGNs increases with redshift from 6% at…

We study the properties of 975 active galactic nuclei (AGN) selected by variability in the Pan-STARRS1 Medium-Deep Survey. Using complementary multi wavelength data from the ultraviolet to the far-infrared, we use SED fitting to determine…

星系天体物理 · 物理学 2016-07-27 S. Heinis , S. Gezari , S. Kumar , W. S. Burgett , H. Flewelling , M. E. Huber , N. Kaiser , R. J. Wainscoat , C. Waters

The luminosity function (LF) of active galactic nuclei (AGN) probes the history of supermassive black hole assembly and growth across cosmic time. To mitigate selection biases, we present a consistent analysis of the AGN LFs derived for…

We determine the evolution of the faint, high-redshift, optical luminosity function (LF) of AGN implied by several observationally-motivated models of the ionizing background. Our results depend crucially on whether we use the total…

天体物理学 · 物理学 2009-11-07 Michael Schirber , James S. Bullock

Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected sample of 136 X-ray sources in the XMM…

The low luminosity QSO (LLQSO) sample consists of type 1 active galactic nuclei (AGN) up to a redshift of z=0.06 in the Hamburg/ESO QSO survey. Its purpose is to study how the brightest AGN in the nearby universe evolve with respect to AGN…

宇宙学与河外天体物理 · 物理学 2017-07-12 Lydia Moser , Jens Zuther , Sebastian Fischer , Gerold Busch , Monica Valencia-S. , Andreas Eckart , Melanie Krips , Julia Scharwaechter

We present a new modeling of the X-ray luminosity function (XLF) of Active Galactic Nuclei (AGN) out to z$\sim$3, dissecting the contribution of main-sequence (MS) and starburst (SB) galaxies. For each galaxy population, we convolved the…

We present the surface density of luminous active galactic nuclei (AGN) associated with a uniformly selected galaxy cluster sample identified in the 8.5 square degree Bootes field of the NOAO Deep Wide-Field Survey. The clusters are…

We constrain the evolution of the galaxy mass and luminosity functions from the analysis of (public) multi-wavelength data in the Chandra Deep Field South (CDFS) area, obtained from the GOODS and other projects, and including very deep…

Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure…

星系天体物理 · 物理学 2014-10-02 Motohiro Enoki , Tomoaki Ishiyama , Masakazu A. R. Kobayashi , Masahiro Nagashima

We present the first measurement of the galaxy luminosity function at 1500A between 0.2<z<1.2 based on GALEX-VVDS observations (1000 spectroscopic redshifts for galaxies with NUV<24.5) and at higher z using existing datasets. Our main…

We combine emission line and X-ray luminosities for 45 sources from the Chandra Deep Field South (CDF-S), and seven HELLAS sources, to obtain a new sample of 52 X-ray selected type-II active galactic nuclei (AGNs). Eighteen of our sources…

天体物理学 · 物理学 2009-11-11 Hagai Netzer , V. Mainieri , P. Rosati , Benny Trakhtenbrot

We present X-ray spectral analyses of the three z>4 Active Galactic Nuclei (AGNs) thus far spectroscopically identified in the Chandra Deep Field-North Survey, at redshifts of 5.186, 4.424, and 4.137. These analyses are made possible by the…

We present new methods to quantify the AGN population in terms of a multi-dimensional luminosity function that describes the space density of sources as a function of both X-ray and radio luminosity. We compile a sample of 1538 radio and…

高能天体物理现象 · 物理学 2025-11-19 Clara M. Pennock , James Aird , Cassandra L. Barlow-Hall

Changing-look active galactic nuclei (CL AGNs) show large changes in luminosity and optical spectral state on time-scales of a few years, and provide a valuable probe of time-dependent accretion in the disc-BLR-torus system. We present a…

星系天体物理 · 物理学 2026-03-19 Yu Tao , Jie Tang , Xuan Wei
‹ 上一页 1 8 9 10 下一页 ›