中文
相关论文

相关论文: Probing the AGN Unification Model at redshift z $\…

200 篇论文

One percent of redshift z~0.1 Active Galactic Nuclei (AGNs) show velocity splitting of a few hundred km/s in the narrow emission lines in spatially integrated spectra. Such line profiles have been found to arise from the bulk motion of…

星系天体物理 · 物理学 2017-09-12 Yang Lyu , Xin Liu

We critically review the basic assumptions of the standard model for the synthesis of the XRB in the light of new data from ultradeep surveys by Chandra and XMM, resolving major parts of it. Important constraints come in particular from the…

天体物理学 · 物理学 2009-11-07 A. Franceschini , V. Braito , D. Fadda

Deep narrow-band surveys have revealed a large population of faint Lyman-alpha (Lya) emitters (LAEs) in the distant Universe, but relatively little is known about the most luminous sources ($L_{Ly\alpha}>10^{42.7}$ erg/s;…

We present an updated model of the cosmic ionizing background from the UV to the X-rays. Relative to our previous model (Faucher-Giguere et al. 2009), the new model provides a better match to a large number of up-to-date empirical…

宇宙学与河外天体物理 · 物理学 2020-02-05 C. -A. Faucher-Giguere

We investigate the process of rapid star formation quenching in a sample of 12 massive galaxies at intermediate redshift (z~0.6) that host high-velocity ionized gas outflows (v>1000 km/s). We conclude that these fast outflows are most…

We present a study of an extended Lyman-alpha (Lya) nebula located in a known overdensity at z~2.38. The data include multiwavelength photometry covering the rest-frame spectral range from 0.1 to 250um, and deep optical spectra of the…

宇宙学与河外天体物理 · 物理学 2014-11-20 C. Scarlata , J. Colbert , H. I. Teplitz , C. Bridge , P. Francis , P. Palunas , B. Siana , G. M. Williger , B. Woodgate

We develop a novel method to identify active galactic nuclei (AGNs) and study the nature of low-luminosity AGNs in the Sloan Digital Sky Survey. This is the second part of a series of papers and we study the correlations between the AGN…

宇宙学与河外天体物理 · 物理学 2015-06-03 Masayuki Tanaka

The combination of the $z=0-13.5$ cosmic star formation history and active galactic nuclei (AGN) luminosity history as inferred by the James Webb Space Telescope is connected to the cosmic spectral energy distribution (CSED) to explore the…

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

Active galactic nuclei (AGN) are thought to play a critical role in shaping galaxies, but their effect on the circumgalactic medium (CGM) is not well studied. We present results from the COS-AGN survey: 19 quasar sightlines that probe the…

We discuss the possible origin of the double-peaked profiles recently observed in Lyman-Alpha Emitters (LAEs) at the epoch of reionization ($z \gtrsim 6.5$) from obscured active galactic nuclei (AGN). Combining the extent of the…

星系天体物理 · 物理学 2021-02-17 Hamsa Padmanabhan , Abraham Loeb

At Cosmic Noon ($z\approx 2-3$), both star formation and Active Galactic Nuclei (AGN) activity peaked, each playing a significant role in ionizing interstellar gas on galaxy-wide scales. The spatial distribution of this ionized gas provides…

Changing-look (CL) Active Galactic Nuclei (AGNs), characterized by appearance/disappearance of broad emission lines in the span of a few years, present a challenge for the AGN unified model, whereby the Type 1 vs. Type 2 dichotomy results…

Some active galactic nuclei (AGN) are surrounded by extended emission-line regions (EELRs), which trace both the illumination pattern of escaping radiation and its history over the light-travel time from the AGN to the gas. From a new set…

It is still a matter of debate whether the properties of galaxies hosting an Active Galactic Nucleus (AGN) are different from the properties of quiescent galaxies. We constructed a sample of ~50 AGN at a mean redshift of <z>~0.6 that lack a…

天体物理学 · 物理学 2007-05-23 Asmus Boehm , Lutz Wisotzki , the GEMS team

We present an estimate of the space density of Active Galactic Nuclei (AGN) at z=3. Combining deep X-ray data with Lyman Break Galaxy (LBG) colour-selection in the rest-frame UV makes for highly efficient identification of AGN in a narrow…

天体物理学 · 物理学 2009-11-10 K. Nandra , E. S. Laird , C. C. Steidel

We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements…

宇宙学与河外天体物理 · 物理学 2015-06-12 Jonathan R. Trump , Alexander D. Hsu , Jerome J. Fang , S. M. Faber , David C. Koo , Dale D. Kocevski

Using low-redshift (z<0.09) samples of AGNs, normal galaxies and groups of galaxies selected from the Sloan Digital Sky Survey (SDSS), we study the environments of type 1 and type 2 AGNs both on small and large scales. Comparisons are made…

星系天体物理 · 物理学 2016-12-07 Ning Jiang , Huiyuan Wang , Houjun Mo , Xiaobo Dong , Tinggui Wang , Hongyan Zhou

Deep X-ray surveys by Chandra and XMM-Newton have resolved about 80% of the 2-10 keV cosmic extragalactic X-ray background (CXRB) into point sources, the majority of which are obscured AGN. The obscuration might be connected to processes…

天体物理学 · 物理学 2008-11-26 D. R. Ballantyne , Y. Shi , G. H. Rieke , J. L. Donley , C. Papovich , J. R. Rigby

The inevitable spread in properties of the toroidal obscuration of active galactic nuclei (AGNs) invalidates the widespread notion that type 1 and 2 AGNs are intrinsically the same objects, drawn randomly from the distribution of torus…

宇宙学与河外天体物理 · 物理学 2015-06-04 Moshe Elitzur