Results 11 to 20 of about 719 (181)
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.
M. Cirasuolo +3 more
+5 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.
Jian‐Min Wang, Luis C. Ho, R. Staubert
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The environments of radio-loud quasars [PDF]
, 2001 6 pages, 4 figures, to appear in the proc.
Jordi Barr, L. Pozzetti, Joanne C. Baker
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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
I. Hook +6 more
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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
V. Ganci +6 more
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Exploring the radio loudness of SDSS quasars with spectral stacking [PDF]
Monthly Notices of the Royal Astronomical SocietyABSTRACT We use new 144 MHz observations over 5634 deg2 from the LOFAR (Low Frequency Array) Two-metre Sky Survey (LoTSS) to compile the largest sample of uniformly selected, spectroscopically confirmed quasars from the 14th data release of the Sloan Digital Sky Survey (SDSS-DR14).
M I Arnaudova +11 more
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The radio loud narrow-line quasar SDSSJ172206.03+565451.6
The Astrophysical Journal, 2005 We report identification of the radio loud narrow-line quasar SDSS J172206.03+565451.6 which we found in the course of a search for radio loud narrow-line Active Galactic Nuclei (AGN). SDSSJ172206.03+565451.6 is only the ~4th securely identified radio loud narrow-line quasar and the second-most radio loudest with a radio index R_1.4 ~ 100-700.
S. Komossa +5 more
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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
A survey for high-redshift radio-loud quasars: optical spectroscopy of S > 0.2 Jy, flat-spectrum radio sources [PDF]
Monthly Notices of the Royal Astronomical Society, 1996 I M Hook, R G Mcmahon, C Hazard
exaly +2 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