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Related papers: Characterizing the Gamma-ray Emission from Low-Lum…

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The X-ray luminosity function (XLF) of galaxies is dominated by AGN (classified by their optical spectra) above Lx=10**42 erg/s, below this value by normal galaxies. The X-ray flux of AGN at low X-ray luminosity therefore contains…

Astrophysics · Physics 2007-05-23 I. Lehmann , G. Hasinger , A. D. Schwope , Th. Boller

An interesting feature in active galactic nuclei (AGN) accreting at low rate is the weakness of the reflection features in their X-ray spectra, which can result from the gradual disappearance of the torus with decreasing accretion rates. It…

We investigate the contribution made by active galactic nuclei (AGN) to the high-redshift, luminous, submillimetre (submm) source population using deep (< 2 mJy/beam) Large Apex Bolometer Camera (LABOCA) 870 um observations within the…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-31 R. M. Bielby , M. D. Hill , N. Metcalfe , T. Shanks

(abbreviated): This paper presents the results of a high resolution radio imaging survey of all known (96) low-luminosity active galactic nuclei (LLAGNs) at D<19Mpc. We find that almost half of all LINERs and low-luminosity Seyferts have…

Astrophysics · Physics 2009-11-07 N. M. Nagar , H. Falcke , A. S. Wilson , J. S. Ulvestad

The Fermi-LAT satellite has recently discovered a small group of radio galaxies and steep spectrum radio sources: the misaligned AGNs (MAGNs) sample. We present the X-ray analysis of all the sources of this sample (7 FRIs and 3 FRIIs) with…

High Energy Astrophysical Phenomena · Physics 2012-05-09 Eleonora Torresi

The detection of gamma rays from a small number of Narrow Line Seyfert 1 galaxies by the LAT instrument onboard Fermi seriously challenged our understanding of AGN physics. Among the most important findings associated with their discovery…

High Energy Astrophysical Phenomena · Physics 2013-04-08 E. Angelakis , L. Fuhrmann , I. Myserlis , I. Nestoras , V. Karamanavis , T. P. Krichbaum , J. A. Zensus , N. Marchili , L. Foschini , H. Ungerechts , A. Sievers

With the advancement of technology, machine learning-based analytical methods have pervaded nearly every discipline in modern studies. Particularly, a number of methods have been employed to estimate the redshift of gamma-ray loud active…

High Energy Astrophysical Phenomena · Physics 2023-12-13 Sarvesh Gharat , Abhimanyu Borthakur , Gopal Bhatta

Using the Gemini Near-InfraRed Spectrograph (GNIRS), we have assembled a complete sample of 20 K-selected galaxies at 2.0<z<2.7 with high quality near-infrared spectra. As described in a previous paper, 9 of these 20 galaxies have strongly…

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…

BL Lac Objects (BL Lacs) and Flat Spectrum Radio Quasars (FSRQs) are radio-loud active galaxies (AGNs) whose jets are seen at a small viewing angle (blazars), while Misaligned Active Galactic Nuclei (MAGNs) are mainly radiogalaxies of type…

High Energy Astrophysical Phenomena · Physics 2018-08-20 G. Chiaro , M. Meyer , N. Alvarez Crespo , R. J. Britto , J. P. Marais , B. van Soelen , D. Salvetti , G. La Mura , D. J Thompson

We present a census of the Compton-thick (CT) active galactic nucleus (AGN) population and the column density ($N_{\rm{H}}$) distribution of AGN in our cosmic backyard using a mid-infrared selected AGN sample within 15 Mpc. The column…

Submillimetre-selected galaxies (SMGs) at high redshift ($z$ $\sim$ 2) are potential host galaxies of active galactic nuclei (AGN). If the local Universe is a good guide, $\sim$ 50$\%$ of the obscured AGN amongst the SMG population could be…

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…

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Masayuki Tanaka

The results of Chandra snapshot observations of 11 LINERs (Low-Ionization Nuclear Emission-line Regions), three low-luminosity Seyfert galaxies, and one HII-LINER transition object are presented. Our sample consists of all the objects with…

Astrophysics · Physics 2010-04-06 Yuichi Terashima , Andrew S. Wilson

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-23 Ming-Yi Lin , Yasuhiro Hashimoto , Sebastien Foucaud

Jetted Active Galactic Nuclei (AGN) exhibit variability across a wide range of time scales. Traditionally, this variability can often be modeled well as a stochastic process. However, in certain cases, jetted AGN variability displays…

High Energy Astrophysical Phenomena · Physics 2025-01-03 P. Penil , A. Domínguez , S. Buson , M. Ajello , S. Adhikari , A. Rico

In a series of papers based on the FIRST and Sloan Digital Sky Surveys (SDSS), we investigate the local population of star-forming galaxies and Active Galactic Nuclei (AGN) in order to clarify the link between these two types of activity,…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-25 Pietro M. Reviglio , David J. Helfand

Blazars are a subclass of active galactic nuclei (AGN) having relativistic jets aligned within a few degrees of our line-of-sight and form the majority of the AGN detected in the TeV regime. The Fermi-Large Area Telescope (LAT) is a…

High Energy Astrophysical Phenomena · Physics 2023-07-04 Atreya Acharyya , Alberto C. Sadun

Low luminosity radio-loud active galactic nuclei (AGN) are generally found in massive red elliptical galaxies, where they are thought to be powered through gas accretion from their surrounding hot halos in a radiatively inefficient manner.…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-05 R. M. J. Janssen , H. J. A. Rottgering , P. N. Best , J. Brinchmann
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