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Related papers: Exploring AGN Activity over Cosmic Time with the S…

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8.4-GHZ radio imaging study of an optically selected sample of early type Seyfert galaxies; comparison of images taken at two epochs reveals possible variation in the nuclear radio flux density in five of them over a seven year period. It…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-25 C. G. Mundell , N. Nagar , P. Ferruit

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…

Astrophysics of Galaxies · Physics 2021-04-13 Kai T. Kono , Taichi Takeuchi , Hiroyuki Tashiro , Kiyotomo Ichiki , Tsutomu T. Takeuchi

We study the space density evolution of active galactic nuclei (AGN) using the $610 \ \mathrm{MHz}$ radio survey of the XXL-North field, performed with the Giant Metrewave Radio Telescope (GMRT). The survey covers an area of $30.4 \…

As a critical part of the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry (TANAMI) program, in November 2007 the Australia Telescope Compact Array (ATCA) started monitoring the radio spectra of a sample of…

High Energy Astrophysical Phenomena · Physics 2012-05-14 J. Stevens , P. G. Edwards , R. Ojha , M. Kadler , F. Hungwe , M. Dutka , S. Tingay , J. P. Macquart , A. Moin , J. Lovell , J. Blanchard

In this work, we study the AGN radio detection effectiveness in the major deep extragalactic surveys, considering different AGN obscuration levels, redshift, and AGN bolometric luminosities. We particularly focus on comparing their radio…

Relativistic jets in active galactic nuclei (AGN) are among the most powerful astrophysical objects discovered to date. Indeed, jetted AGN studies have been considered a prominent science case for SKA, and were included in several different…

At Cosmic Noon ($z\approx 2-3$), both star formation and Active Galactic Nuclei (AGN) activity peaked, each playing a significant role in ionizing interstellar gas on galaxy-wide scales. The spatial distribution of this ionized gas provides…

We present a radio continuum study of photometrically selected cosmic noon (0.5<z<3) post-starburst galaxies (PSBs) in the UKIDSS Deep Survey (UDS) field to assess if radio-mode Active Galactic Nuclei (AGN) are linked to the quenching of…

As the SKA is expected to be operational in the next decade, investigations of the radio sky in the range of 100 MHz to 10 GHz have become important for simulations of the SKA observations. In determining physical properties of galaxies…

Astrophysics of Galaxies · Physics 2020-11-04 Krešimir Tisanić , V. Smolčić , M. Imbrišak , M. Bondi , G. Zamorani , L. Ceraj , E. Vardoulaki , J. Delhaize

Radio observations provide a powerful tool to constrain the assembly of galaxies over cosmic time. Recent deep and wide radio continuum surveys have improved significantly our understanding on radio emission properties of AGNs and SFGs…

Astrophysics of Galaxies · Physics 2025-02-19 Fangyou Gao , Tao Wang , Yijun Wang

The investigation of emission line regions within active galaxies (AGNs) has a rich and extensive history, now extending to the use of AGNs and quasars as "standardizable" cosmological indicators, shedding light on the evolution of our…

Astrophysics of Galaxies · Physics 2023-11-28 Swayamtrupta Panda , Paola Marziani , Bozena Czerny , Alberto Rodriguez-Ardila , Francisco Pozo Nunez

A VLA Sky Survey of the extragalactic sky at S band (2-4 GHz) with polarization information can uniquely probe the magneto-ionic medium in a wide range of astrophysical environments over cosmic time. For a shallow all-sky survey, we expect…

Mapping the average AGN luminosity across galaxy populations and over time encapsulates important clues on the interplay between supermassive black hole (SMBH) and galaxy growth. This paper presents the demography, mean power and cosmic…

Ultra-deep radio surveys are an invaluable probe of dust-obscured star formation, but require a clear understanding of the relative contribution from radio AGN to be used to their fullest potential. We study the composition of the $\mu$Jy…

We select a sample of radio galaxies at high redshifts (z>~1) in the COSMOS field, by cross-matching optical/infrared images with the FIRST radio data. The aim of this study is to explore the high-z radio-loud (RL) AGN population at much…

Astrophysics of Galaxies · Physics 2014-09-05 Ranieri D. Baldi , Alessandro Capetti , Marco Chiaberge , Annalisa Celotti

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

Deep surveys with the SKA1-MID array offer for the first time the opportunity to systematically explore the polarization properties of the microJy source population. Our knowledge of the polarized sky approaching these levels is still very…

We present the evolutionary properties and luminosity functions of the radio sources belonging to the Chandra Deep Field South VLA survey, which reaches a flux density limit at 1.4 GHz of 43 microJy at the field center and redshift ~5, and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 P. Padovani , N. Miller , K. I. Kellermann , V. Mainieri , P. Rosati , P. Tozzi

On a time scale of years to decades, gravitational wave (GW) astronomy will become a reality. Low frequency (nanoHz) GWs are detectable through long-term timing observations of the most stable pulsars. Radio observatories worldwide are…

We present a study of variability time scales in a large sample of Active Galactic Nuclei at several frequencies between 4.8 and 230 GHz. We investigate the differences of various AGN types and frequencies and correlate the measured time…