Results 11 to 20 of about 183 (149)
Radio-loudness Statistics of Quasars from Quaia-VLASS
The Astrophysical Journal Supplement SeriesQuasars are objects of high interest in extragalactic astrophysics, cosmology, and astrometry. One of their useful qualities is their potential radio-loudness.
Nestor Arsenov +3 more
doaj +3 more sources
Is there a Dichotomy in the Radio Loudness Distribution of Quasars? [PDF]
Monthly Notices of the Royal Astronomical Society, 2003 We present a new approach to tackle the issue of radio loudness in quasars. We constrain a (simple) prescription for the intrinsic distribution of radio-to-optical ratios by comparing properties of Monte Carlo simulated samples with those of observed optically selected quasars.
CIRASUOLO M. +3 more
openaire +3 more sources
The central engines of radio-loud quasars [PDF]
Astronomy & Astrophysics, 2003 We have assembled a sample of 37 RLQs that have been imaged with the HST in order to investigate their black hole masses, accretion rates, and the structure of their accretion disks. The black hole masses were estimated from the luminosities of the host galaxies, and the accretion powers were extrapolated from the emission-line luminosities.
Wang, Jian-Min +2 more
openaire +2 more sources
The radio spectral turnover of radio-loud quasars at z > 5 [PDF]
Astronomy & Astrophysics, 2022 We present Karl G. Jansky Very Large Array S- (2–4 GHz), C- (4–8 GHz), and X-band (8–12 GHz) continuum observations toward seven radio-loud quasars at z > 5. This sample has previously been found to exhibit spectral peaks at observed-frame frequencies above ∼1 GHz.
Yali Shao +10 more
openaire +4 more sources
Radio-loud flares from microquasars and radio-loudness of quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2005 5 pages, 3 figures.
NIPOTI, CARLO, Blundell K. M., Binney J.
openaire +3 more sources
GB:1508+5714: a radio-loud quasar with z = 4.30 and the space density of high-redshift radio-loud quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 1995 We report the discovery of a radio loud quasar with a redshift of 4.30. This object, which is the first radio selected quasar with a redshift greater than four, was discovered during an observational investigation into the evolution of the luminosity function of radio loud quasars. Here we describe results based on a sample of ~300, flat spectrum radio
HOOK, IM +6 more
openaire +3 more sources
The Environments of Radio-Loud Quasars [PDF]
, 2001 6 pages, 4 figures, to appear in the proc.
Barr, J. M., Bremer, M. N., Baker, J. C.
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On the masses of black holes in radio-loud quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2001 The central black-hole masses of a sample of radio-loud quasars are estimated by using the data of $H_β$ line-width and the optical continuum luminosity. The vast majority of the quasars in this sample have black-hole masses larger than $10^{8} M_{\odot}$, while a few quasars may contain relatively smaller black-holes.
Gu, Minfeng, Cao, Xinwu, Jiang, D. R.
openaire +2 more sources
Radio loudness along the quasar main sequence [PDF]
Astronomy & Astrophysics, 2019 Context.When can an active galactic nucleus (AGN) be considered radio loud (RL)? Following the established view of the AGNs inner workings, an AGN is RL if associated with relativistic ejections emitting a radio synchrotron spectrum (i.e., it is a “jetted” AGN). In this paper we exploit the AGN main sequence that offers a powerful tool to contextualize
Ganci V. +6 more
openaire +4 more sources
Faint radio-loud quasars: clues to their evolution [PDF]
Monthly Notices of the Royal Astronomical Society, 2005 11 pages, 7 figures, accepted for publication in ...
CIRASUOLO M. +2 more
openaire +2 more sources