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Related papers: The Most Massive Active Galactic Nuclei at $1\less…

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We examine multiple AGN systems (triples and quadruples, in particular) in the \texttt{MassiveBlackII} simulation over a redshift range of $0.06\lesssim z \lesssim 4$. We identify AGN systems (with bolometric luminosity…

Astrophysics of Galaxies · Physics 2020-02-19 Aklant K. Bhowmick , Tiziana Di Matteo , Adam D. Myers

We perform a detailed investigation of moderate-to-high quality X-ray spectra of ten of the most luminous active galactic nuclei (AGNs) known at z>4 (up to z~6.28). This study includes five new XMM observations and five archived X-ray…

Astrophysics · Physics 2008-11-26 O. Shemmer , W. N. Brandt , C. Vignali , D. P. Schneider , X. Fan , G. T. Richards , M. A. Strauss

A sample of 10 nearby intermediate-type active galactic nuclei (AGN) drawn from the Sloan Digital Sky Survey (SDSS-DR7) is presented. The aim of this work is to provide estimations of the black hole mass for the sample galaxies from the…

We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift ($0.3<z<1.0$) radio-loud active galactic nuclei (AGN) with powerful relativistic jets ($L_{1.4GHz} >10^{27}$ WHz$^{-1}$), previously classified as…

We present VLT/XSHOOTER rest-frame UV-optical spectra of 10 Hot Dust-Obscured Galaxies (Hot DOGs) at $z\sim2$ to investigate AGN diagnostics and to assess the presence and effect of ionized gas outflows. Most Hot DOGs in this sample are…

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…

Cosmology and Nongalactic Astrophysics · Physics 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

The masses of 68 supermassive black holes (SMBHs) in nearby (z<0.15) active galactic nuclei (AGNs) detected by the INTEGRAL observatory in the hard X-ray energy band (17-60 keV) outside the Galactic plane (|b| > 5 degrees) have been…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-24 G. A. Khorunzhev , S. Yu. Sazonov , R. A. Burenin , A. Yu. Tkachenko

The remnants of galaxy mergers may host multiple off-nuclear massive black holes (MBHs), some of which may wander indefinitely within the host galaxy halos. Tracing the population of offset MBHs is essential for understanding how the…

Astrophysics of Galaxies · Physics 2025-09-15 R. Scott Barrows , Julia M. Comerford

Changing-look active galactic nuclei (AGNs) present an important laboratory to understand the origin and physical properties of the broad-line region (BLR). We investigate follow-up optical spectroscopy spanning $\sim 500$ days after the…

Astrophysics of Galaxies · Physics 2022-08-04 Ruancun Li , Luis C. Ho , Claudio Ricci , Benny Trakhtenbrot , Iair Arcavi , Erin Kara , Daichi Hiramatsu

We present the mean spectral energy distribution (SED) of a sample of optically selected quasars (QSOs) at redshifts of $1 \le z \le 5$. To derive it, we exploit photometric information from SDSS, UKIDSS, and WISE surveys in combination…

Astrophysics of Galaxies · Physics 2019-02-19 Federico Bianchini , Giulio Fabbian , Andrea Lapi , Joaquin Gonzalez-Nuevo , Roberto Gilli , Carlo Baccigalupi

We present results of the cross-correlation analysis between active galactic nuclei (AGNs) and galaxies at redshift 0.1-1. We obtain data of ~10,000 SDSS AGNs in which their virial masses with a super-massive black hole (SMBH) were…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Yutaka Komiya , Yuji Shirasaki , Masatoshi Ohishi , Yoshihiko Mizumoto

Composite spectra derived from HST observations of moderate redshift (z~1) quasars show that the peak of the spectral energy distribution is at ~1000 A, and that the ionizing continuum falls off smoothly to shorter wavelengths as $f_\nu…

Astrophysics · Physics 2007-05-23 Gerard A. Kriss

Aims: We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN), of all degrees of activity, in the wavelength interval of 0.8-2.4 microns, including the fluxes of the observed emission lines. We analyze the spectroscopic…

Astrophysics · Physics 2009-11-11 R. Riffel , A. Rodriguez-Ardila , M. G. Pastoriza

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…

AGN-driven outflows are invoked by galaxy evolutionary models to quench star formation and to explain the origin of the relations observed locally between super massive black holes and their host galaxies. This work aims to detect the…

We investigate quasar outflows at $z \geq 6$ by performing zoom-in cosmological hydrodynamical simulations. By employing the SPH code GADGET-3, we zoom in the $2 R_{200}$ region around a $2 \times 10^{12} M_{\odot}$ halo at $z = 6$, inside…

Dust-obscured galaxies are thought to represent an early evolutionary phase of massive galaxies in which the active galactic nucleus (AGN) is still deeply buried in significant amounts of dusty material and its emission is strongly…

Obscured AGN represent a significant fraction of the entire AGN population, especially at high redshift (~70% at z=3--5). They are often characterized by the presence of large gas and dust reservoirs that are thought to sustain and possibly…

We present a detailed spectral analysis of the brightest Active Galactic Nuclei (AGN) identified in the 7Ms Chandra Deep Field South (CDF-S) survey over a time span of 16 years. Using a model of an intrinsically absorbed power-law plus…

In the last decade of Active Galactic Nuclei (AGN) monitoring programs, the Mets\"ahovi Radio Observatory detected multiple times seven powerful flaring narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz. Several hypotheses have been proposed,…