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Related papers: The radio emission from Active Galactic Nuclei

200 papers

Radio observations being insensitive to the dust-obscuration, have been exploited to unveil the population of Active Galactic Nuclei (AGN) residing in galaxies with large dust content. In this paper, we investigate the radio characteristics…

Astrophysics of Galaxies · Physics 2022-11-22 Abhijit Kayal , Veeresh Singh , C. H. Ishwara Chandra , Yogesh Wadadekar , Sushant Dutta

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…

In this paper we give a brief review of the astrophysics of active galactic nuclei (AGN). After a general introduction motivating the study of AGNs, we discuss our present understanding of the inner workings of the central engines, most…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-18 Henric Krawczynski , Ezequiel Treister

Mature radio galaxies such as M87 belong to a specific subclass of active galaxies (AGN) whose evolution in time endows them with five distinguishing characteristics, including (1) low excitation emission, (2) low star formation rates, (3)…

High Energy Astrophysical Phenomena · Physics 2024-09-27 Chandra B. Singh , Michael Williams , David Garofalo , Luis Rojas Castillo , Landon Taylor , Eddie Harmon

There is now strong evidence that many low-luminosity AGNs (LLAGNs) contain accreting massive black holes and that the nuclear radio emission is dominated by parsec-scale jets launched by these black holes. Here, we present preliminary…

Astrophysics · Physics 2007-05-23 N. M. Nagar , A. S. Wilson , H. Falcke , J. S. Ulvestad , C. G. Mundell

To understand the origin of radio emission in radio-quiet AGN and differentiate between the contributions from star formation, AGN accretion, and jets, we have observed a nearby sample of Seyfert galaxies along with a comparison sample of…

Astrophysics of Galaxies · Physics 2020-10-14 Biny Sebastian , P. Kharb , C. P. O' Dea , J. F. Gallimore , S. A. Baum

Post-merger galaxies are unique laboratories to study the triggering and interplay of star-formation and AGN activity. Combining new, high resolution, 10 GHz Jansky Very Large Array (VLA) observations with archival radio surveys, we have…

Astrophysics of Galaxies · Physics 2023-09-08 Gregory Walsh , Sarah Burke-Spolaor

This is the second of a series of three papers exploring the connection between the multiwavelength properties of AGN in nearby early-type galaxies and the characteristics of their hosts. In Capetti et al. (2005) we presented a study of the…

Astrophysics · Physics 2009-11-11 B. Balmaverde , A. Capetti

The question as to whether the distribution of radio-loudness in active galactic nuclei (AGN) is actually bimodal has been discussed extensively in the literature. Futhermore, there have been claims that radio-loudness depends on black hole…

Astrophysics · Physics 2009-11-13 Stephen E. Rafter , D. Michael Crenshaw , Paul J. Wiita

Many massive early-type galaxies host central radio sources and hot X-ray atmospheres indicating the presence of radio-mechanical active galactic nucleus (AGN) feedback. The duty cycle and detailed physics of the radio-mode AGN feedback is…

Most massive galaxies are now thought to go through an Active Galactic Nucleus (AGN) phase one or more times. Yet, the cause of triggering and the variations in the intrinsic and observed properties of AGN population are still poorly…

Astrophysics of Galaxies · Physics 2018-10-18 Pallavi Patil , Kristina Nyland , Jeremy J. Harwood , Amy Kimball , Dipanjan Mukherjee

Active Galactic Nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique observational signatures that cover the full electromagnetic spectrum over more than twenty…

Radio loud active galactic nuclei (AGN) are on average 1000 times brighter in the radio band compared to radio quiet AGN. We investigate whether this radio loud/quiet dichotomy can be due to differences in the spin of the central black…

High Energy Astrophysical Phenomena · Physics 2010-02-21 Alexander Tchekhovskoy , Ramesh Narayan , Jonathan C. McKinney

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

We have studied the host galaxies of a sample of radio-loud AGN spanning more than four decades in the energy output of the nucleus. The core sample includes 40 low-power sources (BL Lac objects) and 22 high-power sources (radio-loud…

Astrophysics · Physics 2009-11-07 Matthew O'Dowd , C. Megan Urry , Riccardo Scarpa

Compact radio cores in radio-loud active galactic nuclei (AGNs) are classical targets of Very-Long-Baseline interferometric (VLBI) research. Until today little has been known about their X-ray properties in comparison to radio-quiet AGNs.…

Astrophysics · Physics 2007-05-23 M. Kadler , E. Ros , J. Kerp , Y. Y. Kovalev , J. A. Zensus

The supermassive black holes in active galactic nuclei (AGN) and stellar-mass black holes in X-ray binaries (XRBs) are believed to work in a similar way. While XRBs evolve rapidly and several sources have undergone a few complete cycles…

Astrophysics of Galaxies · Physics 2017-07-26 Jiri Svoboda , Matteo Guainazzi , Andrea Merloni

We study the nature of the faint radio source population detected in the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Early Science data in the COSMOS field, focusing on the properties of the radio-loud active…

We report on the JVLA observations of three high redshift Active Galactic Nuclei (AGN), having a black hole mass estimated to be among the largest known. Two of them, SDSS J0100+2802 and SDSS J0306+1853 at redshift 6.326 and 5.363…

High Energy Astrophysical Phenomena · Physics 2021-12-01 Tullia Sbarrato , Gabriele Ghisellini , Gabriele Giovannini , Marcello Giroletti

We present the completed results of a high resolution radio imaging survey of all (~200) low-luminosity active galactic nuclei (LLAGNs) and AGNs in the Palomar Spectroscopic Sample. The high incidences of pc-scale radio nuclei, with…

Astrophysics · Physics 2009-11-10 Neil M. Nagar , Heino Falcke , Andrew S. Wilson