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相关论文: Active Galactic Nuclei Selected from GALEX Spectro…

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A strong X-ray emission is one of the defining signatures of nuclear activity in galaxies. According to the Unified Model for Active Galactic Nuclei (AGN), both the X-ray radiation and the prominent broad emission lines, characterizing the…

星系天体物理 · 物理学 2015-06-17 G. La Mura , M. Berton , S. Ciroi , V. Cracco , F. Di Mille , P. Rafanelli

A sample of radio-loud active galactic nuclei (AGN) at 2cm is studied to test the isotropic distribution of radio sources in the sky and their uniform distribution in space. The sample is complete flux-density limits of 1.5Jy for positive…

天体物理学 · 物理学 2017-08-23 T. G. Arshakian , E. Ros , J. A. Zensus , M. L. Lister

We construct a sample of 3,516 radio-loud host galaxies of active galactic nuclei (AGN) from the optical Sloan Digital Sky Survey (SDSS) and Faint Images of the Radio Sky at Twenty cm (FIRST). These have 1.4 GHz luminosities in the range…

宇宙学与河外天体物理 · 物理学 2011-08-17 Elizabeth J. A. Mannering , Diana M. Worrall , Mark Birkinshaw

In order to understand the interactions between active galactic nuclei (AGN) and star formation during the evolution of galaxies, we investigate 142 galaxies detected in both X-ray and 70{\mu}m observations in the COSMOS (Cosmic Evolution…

宇宙学与河外天体物理 · 物理学 2016-02-23 Ming-Yi Lin , Yasuhiro Hashimoto , Sebastien Foucaud

We use Herschel-PACS far-infrared data, combined with previous multi-band information and mid-IR spectra, to properly account for the presence of an active nucleus and constrain its energetic contribution in luminous infrared (IR) sources…

We present a uniform X-ray spectral analysis of eight type-1 active galactic nuclei (AGN) that have been previously observed with relativistically broadened iron emission lines. Utilizing data from the XMM-Newton European Photon Imaging…

高能天体物理现象 · 物理学 2015-05-13 Laura W. Brenneman , Christopher S. Reynolds

We have compiled a sample of 165 radio galaxies from the literature to study the properties of the extended emission line regions and their interaction with the radio source over a large range of redshift 0<z<5.2. For each source, we have…

天体物理学 · 物理学 2007-05-23 Carlos De Breuck , Huub Rottgering , George Miley , Wil van Breugel , Philip Best

For measurement of the AGN luminosity function and its evolution, X-ray selection samples all types of AGN and provides reduced obscuration bias in comparison with UV-excess or optical surveys. The apparent decline in optically-selected…

We investigate the physical cause of the great range in the ionization level seen in the spectra of narrow lined active galactic nuclei (AGN). Mean field independent component analysis identifies examples of individual SDSS galaxies whose…

宇宙学与河外天体物理 · 物理学 2015-06-17 Chris T. Richardson , James T. Allen , Jack A. Baldwin , Paul C. Hewett , Gary J. Ferland

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

The determination of the broad (0.1-100 keV) spectra of active galaxies is crucial for understanding and discriminating among emission models, for estimating the properties of the Comptonising/reflecting region around the central black hole…

高能天体物理现象 · 物理学 2013-02-12 Manuela Molina , L. Bassani , A. Malizia , A. Bazzano , P. Ubertini , A. J. Bird

Quasars and active galactic nuclei (AGN) are significant contributors to the metagalactic ionizing background at redshifts z < 3. Recent HST/COS composite spectra of AGN find a harder flux distribution in the Lyman continuum, F_nu ~…

星系天体物理 · 物理学 2020-07-08 Michael Shull , Charles Danforth

Ultraviolet (UV) and X-ray photons from active galactic nuclei (AGNs) can ionize hydrogen in the intergalactic medium (IGM). We solve radiative transfer around AGNs in high redshift to evaluate the 21-cm line emission from the neutral…

星系天体物理 · 物理学 2021-04-13 Kai T. Kono , Taichi Takeuchi , Hiroyuki Tashiro , Kiyotomo Ichiki , Tsutomu T. Takeuchi

Analysis of the frequency and physical properties of galaxies with star-formation and AGN activity in different environments in the local universe is a cornerstone for understanding structure formation and galaxy evolution. We have built a…

天体物理学 · 物理学 2008-11-26 Pietro Reviglio , David J. Helfand

The goal of this work is to search for Active Galactic Nuclei (AGN) in the Galactic disc at very low latitudes with |b| $<$ 2$^\circ$. For this, we studied the five sources from the VVV near-infrared galaxy catalogue that have also WISE…

We present an analysis of a sample of robust high redshift galaxies selected photometrically from the `blank' fields of the Prime Extragalactic Areas for Reionization Science (PEARLS) survey and Early Release Observations (ERO) data of the…

We construct the rest-frame 2--10 keV intrinsic X-ray luminosity function of Active Galactic Nuclei (AGNs) from a combination of X-ray surveys from the all-sky Swift BAT survey to the Chandra Deep Field-South. We use ~3200 AGNs in our…

We present a sample of 252 broad-line Active Galactic Nuclei (BLAGNs), incorporating 171 newly identified sources, spanning a redshift interval from $z$ = 0.8 to 7.2. We have analyzed spectroscopic data from the NIRSpec instrument aboard…

星系天体物理 · 物理学 2025-12-04 Caroline Baccus , Xinfeng Xu

We compute the ionizing radiation field at low redshift, arising from Seyferts, QSOs, and starburst galaxies. This calculation combines recent Seyfert luminosity functions, extrapolated ultraviolet fluxes from our IUE-AGN database, and a…

天体物理学 · 物理学 2009-10-31 J. M. Shull , D. Roberts , M. L. Giroux , S. V. Penton , M. A. Fardal