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Related papers: Angular Broadening of Intraday Variable AGN. II. I…

200 papers

In the framework of a systematic ALMA study of IR-selected main-sequence and starburst galaxies at z~1-1.7 at typical ~1" resolution, we report on the effects of mid-IR- and X-ray-detected active galactic nuclei (AGN) on the reservoirs and…

This overview provides a historical perspective highlighting the pioneering role which the fairly modest observational facilities of ARIES have played since the 1990s in systematically characterizing the optical variability on hour-like…

Astrophysics of Galaxies · Physics 2017-11-16 Gopal-Krishna , Paul J. Wiita

In order to better understand how active galactic nuclei (AGN) effect the interstellar media of their host galaxies, we perform a meta-analysis of the CO emission for a sample of $z=0.01-4$ galaxies from the literature with existing CO…

Astrophysics of Galaxies · Physics 2019-07-10 Allison Kirkpatrick , Chelsea Sharon , Erica Keller , Alexandra Pope

In unified models, different types of active galaxy nuclei correspond to a single class of objects, where their observed differences are solely due to the different orientations of the obscuring material around the central inner regions.…

Astrophysics of Galaxies · Physics 2017-09-06 Carlos Guillermo Bornancini , Mónica Silvia Taormina , Diego García Lambas

We analyze the broadband photometric light curves of Seyfert 1 galaxies from the Sergeev et al. (2005) sample and find that a) perturbations propagating across the continuum emitting region are a general phenomenon securely detected in most…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Doron Chelouche

Dust reprocesses the intrinsic radiation of active galactic nuclei (AGNs) to emerge at longer wavelengths. The observed mid-infrared (MIR) luminosity depends fundamentally on the luminosity of the central engine, but in detail it also…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 N. A. Levenson , J. T. Radomski , C. Packham , R. E. Mason , J. J. Schaefer , C. M. Telesco

X-ray surveys have revealed a new class of active galactic nuclei (AGN) with a very low observed fraction of scattered soft X-rays, f_scat < 0.5%. Based on X-ray modeling these "X-ray new-type", or low observed X-ray scattering…

Astrophysics of Galaxies · Physics 2015-06-17 S. F. Hoenig , P. Gandhi , D. Asmus , R. F. Mushotzky , R. Antonucci , Y. Ueda , K. Ichikawa

The emission line luminosity function of active galactic nuclei (AGN) is measured from about 3000 AGN included in the main galaxy sample of the Sloan Digital Sky Survey within a redshift range of $0<z<0.15$. The $\Ha$ and [OIII]$\lambda…

We present a sample of twenty-one ROSAT bright active galactic nuclei (AGN), representing a range of spectral classes, and selected for follow-up snap-shot observations with XMM-Newton. The typical exposure was between 5-10 ks. The objects…

Astrophysics · Physics 2009-11-13 L. C. Gallo , I. Lehmann , W. Pietsch , Th. Boller , W. Brinkmann , P. Friedrich , D. Grupe

We study the statistical properties of the Normalized Excess Variance of variability process characterized by a red-noise power spectral density (PSD), as the case of Active Galactic Nuclei (AGN). We perform Monte Carlo simulations of…

High Energy Astrophysical Phenomena · Physics 2015-06-04 V. Allevato , M. Paolillo , I. Papadakis , C. Pinto

Active galactic nuclei (AGN) are the signposts of black hole growth, and likely play an important role in galaxy evolution. An outstanding question is whether AGN of different spectral types indicate different evolutionary stages in the…

We present the analysis of four NuSTAR observations of the luminous infrared galaxy merger NGC 6240, hosting a close pair of highly obscured active galactic nuclei (AGN). Over a period of about two years, the source exhibits hard X-ray…

High Energy Astrophysical Phenomena · Physics 2017-08-23 Emanuele Nardini

We present a sample of low-resolution 5-38um Spitzer IRS spectra of the inner few square kiloparsecs of 59 nearby galaxies spanning a large range of star formation properties. A robust method for decomposing mid-infrared galaxy spectra is…

In order to examine the relative importance of powerful starbursts and Compton-thick AGNs in NGC 6240, we have obtained mid-infrared images and low-resolution spectra of the galaxy with sub-arcsecond spatial resolution using the Keck…

Astrophysics · Physics 2008-11-26 E. Egami , G. Neugebauer , B. T. Soifer , K. Matthews , E. E. Becklin , M. E. Ressler

We report a new sample of obscured active galactic nuclei (AGNs) selected from the XMM serendipitous source and AKARI point-source catalogs. We match X-ray sources with infrared (18 and 90 micron) sources located at |b|>10 deg to create a…

Astrophysics of Galaxies · Physics 2015-11-18 Yuichi Terashima , Yoshitaka Hirata , Hisamitsu Awaki , Shinki Oyabu , Poshak Gandhi , Yoshiki Toba , Hideo Matsuhara

We study the properties of 56 massive (M$_{\rm{\star}}$ > 10$^{10}$ M$_{\odot}$) galaxies at $z<1$ that host AGN, detected via their broadband optical variability in the VST-COSMOS survey. VST-COSMOS provides a nearly-identical single visit…

Astrophysics of Galaxies · Physics 2026-02-18 B. Bichang'a , D. De Cicco , S. Kaviraj , I. Lazar , A. Watkins , G. Martin , D. Kakkad

We present an analysis of the nuclear variability of $\sim28,000$ nearby ($z<0.15$) galaxies with Sloan Digital Sky Survey (SDSS) spectroscopy in Stripe 82. We construct light curves using difference imaging of SDSS g-band images, which…

Astrophysics of Galaxies · Physics 2018-12-12 Vivienne F. Baldassare , Marla Geha , Jenny Greene

Over ten mid-infrared (mid-IR) and X-ray models are currently attempting to describe the nuclear obscuring material of active galactic nuclei (AGNs), but many questions remain unresolved. This study aims to determine the physical parameters…

We report measurements of time delays of up to 8 minutes in the centimeter wavelength variability patterns of the intra-hour scintillating quasar PKS 1257-326 as observed between the VLA and the ATCA on three separate epochs. These time…

This is the fifth paper in a series of investigations of the clustering properties of luminous, broad-emission-line active galactic nuclei (AGN) identified in the ROSAT All-Sky Survey (RASS) and Sloan Digital Sky Survey (SDSS). In this work…

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