Results 91 to 100 of about 10,384 (186)
The Astrophysical JournalNarrow-line Seyfert 1 galaxies (NLS1s) are generally known to be radio-quiet active galactic nuclei, but a tiny subset of them are found to be extremely radio-loud with radio loudness parameter ( R _1.4 GHz ) > 100.
Veeresh Singh +3 more
doaj +1 more source
A Sample of Quasars with Strong Nitrogen Emission Lines from the Sloan Digital Sky Survey [PDF]
, 2008 We report on 293 quasars with strong NIV] lambda 1486 or NIII] lambda 1750 emission lines (rest-frame equivalent width > 3 \AA) at 1.7 < z < 4.0 selected from the Sloan Digital Sky Survey (SDSS) Fifth Data Release.
Fan, Xiaohui +2 more
core +2 more sources
The Jet-Disk Coupling of Seyfert Galaxies from a Complete Hard X-ray Sample
Universe, 2020 We analyze the jet-disk coupling for different subsamples from a complete hard X-ray Seyfert sample to study the coupling indices and their relation to accretion rate.
Xiang Liu +3 more
doaj +1 more source
Optical off-nuclear spectra of quasar hosts and radio galaxies [PDF]
, 2000 We present optical (~3200A to ~9000A) off-nuclear spectra of 26 powerful active galaxies in the redshift range 0.1 < z < 0.3, obtained with the Mayall and William Herschel 4-meter class telescopes.
Boroson, Todd +3 more
core +3 more sources
Probing the Low-radio-frequency Emission in PG Quasars with the uGMRT. II
The Astrophysical Journal Supplement SeriesWe present results from uGMRT 685 MHz observations of 87 QSOs belonging to the Palomar–Green (PG) quasar sample with z
Sanna Gulati +5 more
doaj +1 more source
Black Hole Mass Estimates of Radio Selected Quasars
, 2002 The black hole (BH) mass in the centre of AGN has been estimated for a sample of radio-selected flat-spectrum quasars to investigate the relationship between BH mass and radio properties of quasars. We have used the virial assumption with measurements of
A. Y. K. N. Oshlack +6 more
core +1 more source
Resolving the Powerful Radio-loud Quasar at z ∼ 6 [PDF]
The Astrophysical Journal, 2018 We present high angular resolution imaging ($23.9 \times 11.3$ mas, $138.6 \times 65.5$ pc) of the radio-loud quasar PSO~J352.4034$-$15.3373 at $z=5.84$ with the Very Long Baseline Array (VLBA) at 1.54 GHz. This quasar has the highest radio-to-optical flux density ratio at such a redshift, making it the radio-loudest source known to date at $z \sim 6$.
Emmanuel Momjian +4 more
openaire +3 more sources
The relationship between the emission line, continuum luminosity, and Baldwin effect in blazars
Astronomy & AstrophysicsAims. This study investigates the relationship between the Mg II λ2798 Å emission line and the 3000 Å continuum luminosity, as well as the Baldwin effect, in a sample of 40’,685 radio-quiet (RQ) quasars and 441 flat spectrum radio quasars (FSRQs ...
Patiño-Álvarez Víctor M. +5 more
doaj +1 more source
IRAS observations of radio-quiet and radio-loud quasars
The Astrophysical Journal, 1984 Observations from 12 to 100 microns are presented of two radio-quiet and three radio-loud quasars. Over this wavelength range, all five have grossly similar continuum energy distributions. The continua of the radio-loud quasars are consistent with synchrotron radiation.
Neugebauer, G. +9 more
openaire +3 more sources
Unveiling New Giant Radio Quasars from the TGSS Sky and Their Large-scale Environment
The Astrophysical Journal Supplement SeriesGiant radio quasars (GRQs) are radiatively efficient radio-loud active galactic nuclei that propel large-scale radio jets with projected lengths of more than 0.7 Mpc. We report the discovery of 53 new GRQs within a redshift range of 0.14–2.38, as well as
Souvik Manik +3 more
doaj +1 more source