Results 71 to 80 of about 183 (149)
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
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Discovery of a Radio-loud/Radio-quiet Binary Quasar
The Astrophysical Journal, 1999 8 pages, 3 figures, to appear in Astrophysical Journal ...
Brotherton, M. S. +5 more
openaire +2 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
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
Red companions to a z=2.15 radio-loud quasar [PDF]
Monthly Notices of the Royal Astronomical Society, 2000 We have conducted observations of the environment around the z=2.15 radio loud quasar 1550-269 in search of distant galaxies associated either with it or the z=2.09 CIV absorber along its line of sight. Such objects will be distinguished by their red colours, R-K>4.5.
openaire +2 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
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
Discovery of spectacular quasar-driven superbubbles in red quasars. [PDF]
Sci Adv, 2023 Shen L +9 more
europepmc +1 more source
Diverse Molecular Gas Excitations in Quasar Host Galaxies at z ∼ 6
The Astrophysical JournalWe present observations using the Northern Extended Millimetre Array (NOEMA) of CO and H _2 O emission lines and the underlying dust continuum in two quasars at z ∼ 6, i.e., P215−16 at z = 5.78 and J1429+5447 at z = 6.18.
Jianan Li +19 more
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Exploring the radio loudness of SDSS quasars with spectral stacking
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
openaire +3 more sources