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Related papers: AGN dichotomy beyond radio loudness: a Gaussian Mi…

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Combined investigations of the clustering properties of galaxies of different spectral type and high-redshift quasars strongly suggest local ellipticals to be the parent population of optically bright Active Galactic Nuclei (AGN). However,…

Astrophysics · Physics 2007-05-23 Manuela Magliocchetti

Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation…

Astrophysics of Galaxies · Physics 2017-12-27 C. L. Hale , M. J. Jarvis , I. Delvecchio , P. W. Hatfield , M. Novak , V. Smolcic , G. Zamorani

We present results from uGMRT 685 MHz observations of 87 QSOs belonging to the Palomar Green (PG) quasar sample with $z<0.5$. Radio emission is detected in all sources except for 3 radio-quiet (RQ) sources, viz., PG 0043+039, PG 1121+422,…

Astrophysics of Galaxies · Physics 2025-10-06 Sanna Gulati , Silpa Sasikumar , Preeti Kharb , Luis C. Ho , Salmoli Ghosh , Janhavi Baghel

Several problems regarding the process of galaxy formation are still open. One of them is the role played by AGN phenomena in contributing to galaxy build-up and to Star Formation (SF) quenching. On the other hand, the theory of AGN…

Astrophysics of Galaxies · Physics 2015-04-15 Nicola Malavasi , Sandro Bardelli , Paolo Ciliegi , Olivier Ilbert , Lucia Pozzetti , Elena Zucca

We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. We find that AGNs form two distinct and well separated sequences on the radio-loudness -…

Astrophysics · Physics 2007-07-17 L. Stawarz , M. Sikora , J. -P. Lasota

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

We compare the optical properties of the host galaxies of radio-quiet (RQ) and radio-loud (RL) Type 2 active galactic nuclei (AGNs) to infer whether the jet production efficiency depends on the host properties or is determined just by…

Astrophysics of Galaxies · Physics 2017-09-29 D. Kozieł-Wierzbowska , N. Vale Asari , G. Stasińska , M. Sikora , E. I. Goettems , A. Wójtowicz

The cosmic evolution of bias of different source populations with underlying dark matter density field in post reionization era can shed light on large scale structures. Studying the angular and spatial distribution of different compact…

Astrophysics of Galaxies · Physics 2021-01-13 Arnab Chakraborty , Prasun Dutta , Abhirup Datta , Nirupam Roy

Despite decades of study, it remains unclear whether there are distinct radio-loud and radio-quiet populations of quasi-stellar objects (QSOs). Early studies were limited by inhomogeneous QSO samples, inadequate sensitivity to probe the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Amy E. Kimball , Kenneth I. Kellermann , James J. Condon , Zeljko Ivezic , Richard A. Perley

We study the Extended Chandra Deep Field South (E-CDFS) Very Large Array sample, which reaches a flux density limit at 1.4 GHz of 32.5 microJy at the field centre and redshift ~ 4, and covers ~ 0.3 deg^2. Number counts are presented for the…

Astrophysics of Galaxies · Physics 2015-08-06 P. Padovani , M. Bonzini , K. I. Kellermann , N. Miller , V. Mainieri , P. Tozzi

This paper presents a study of the local radio source population, by cross-comparing the data from the first data release (DR1) of the LOFAR Two-Metre Sky Survey (LoTSS) with the Sloan Digital Sky Survey (SDSS) DR7 main galaxy spectroscopic…

The recent development of unified theories of active galactic nuclei (AGN) has indicated that there are two physically distinct classes of these objects - radio-loud and radio-quiet. The primary observational distinctions between the two…

Astrophysics · Physics 2016-08-30 Andrew S. Wilson , Edward J. M. Colbert

The appearance of active galactic nuclei (AGN) depends so strongly on orientation that our current classification schemes are dominated by random pointing directions instead of more interesting physical properties. Light from the centers of…

Astrophysics · Physics 2011-07-18 C. Megan Urry , Paolo Padovani

The distribution of radio to optical fluxes in AGN is bimodal. The physical origin for this bimodality is not understood. In this Letter I describe observational evidence, based on the Boroson & Green PG quasar sample, that the radio…

Astrophysics · Physics 2009-10-31 Ari Laor

The radio-loud/radio-quiet (RL/RQ) dichotomy in quasars is still an open question. Although it is thought that accretion onto supermassive black holes in the centre the host galaxies of quasars is responsible for some radio continuum…

Radio observations allow us to identify a wide range of active galactic nuclei (AGN), which play a significant role in the evolution of galaxies. Amongst AGN at low radio-luminosities is the 'radio-quiet' quasar (RQQ) population, but how…

A global understanding of Active Galactic Nuclei (AGN) and their host galaxies hinges on completing a census of AGN activity without selection biases down to the low-luminosity regime. Toward that goal, we identify AGN within faint radio…

Astrophysics of Galaxies · Physics 2020-10-14 Stacey Alberts , Wiphu Rujopakarn , George Rieke , Preshanth Jagannathan , Kristina Nyland

Measurement of the evolution of both active galactic nuclei (AGN) and star-formation in galaxies underpins our understanding of galaxy evolution over cosmic time. Radio continuum observations can provide key information on these two…

We present the first results from the Quasar Feedback Survey, a sample of 42 z<0.2, [O III] luminous AGN (L[O III]>10^42.1 ergs/s) with moderate radio luminosities (i.e. L(1.4GHz)>10^23.4 W/Hz; median L(1.4GHz)=5.9x10^23 W/Hz). Using high…

The radio-loud AGN unification model associates powerful radio galaxies with radio-loud quasars and blazars. In analogy with the radio-quiet scheme, the nuclear regions of objects showing only narrow emission lines in their optical spectrum…

Astrophysics · Physics 2017-08-23 Marco Chiaberge