Results 51 to 60 of about 719 (181)
The Astrophysical Journal, 2023 Dual and off-nucleus active supermassive black holes are expected to be common in the hierarchical structure formation paradigm, but their identification at parsec scales remains a challenge due to strict angular resolution requirements.
Yu-Ching Chen +7 more
doaj +1 more source
Intranight optical variability of BL Lacs, radio-quiet quasars and radio-loud quasars [PDF]
Monthly Notices of the Royal Astronomical Society, 2005 8 pages, 3 Postscript figures, Accepted for publication in MNRAS, uses mn2e ...
Stalin, C. S. +4 more
openaire +2 more sources
PG 1004+130: Hybrid Morphology Source or a Restarted FRII? A uGMRT Polarimetric Investigation
The Astrophysical Journal, 2023 We present the polarization image of the hybrid morphology and broad absorption line quasar PG 1004+130 at 694 MHz obtained with the upgraded Giant Metrewave Radio Telescope. We detect linear polarization in this source’s core, jets, and lobes.
Salmoli Ghosh +3 more
doaj +1 more source
Why Radio Quiet Quasars are Preferred over Radio Loud Quasars Regardless of Environment and Redshift [PDF]
The Astrophysical Journal, 2020 Abstract Evidence has accumulated suggesting the clustering of radio loud quasars (RLQs) is greater than for radio quiet quasars. We interpret these results in a context in which the fraction of RLQ formation is f RLQ ≤ f RQQ compared to that for radio quiet quasars for all environments and redshifts ...
David Garofalo +3 more
openaire +2 more sources
Powerful Radio-loud Quasars Are Triggered by Galaxy Mergers in the Cosmic Bright Ages
The Astrophysical JournalWhile supermassive black holes are ubiquitous features of galactic nuclei, only a small minority are observed during episodes of luminous accretion. The physical mechanism(s) driving the onset of fueling and ignition in these active galactic nuclei (AGN)
Peter Breiding +17 more
doaj +1 more source
The Astrophysical JournalWe investigate the group-scale environment of 15 luminous quasars (luminosity L _3000 > 10 ^46 erg s ^−1 ) from the Cosmic Ultraviolet Baryon Survey (CUBS) at redshift z ≈ 1.
Jennifer I-Hsiu Li +13 more
doaj +1 more source
Jet Physics of Accreting Super-Massive Black Holes in the Era of the Fermi Gamma-ray Space Telescope
Frontiers in Astronomy and Space Sciences, 2017 The Fermi Gamma-ray Space Telescope with its main instrument on-board, the Large Area Telescope (LAT), opened a new era in the study of high-energy emission from Active Galactic Nuclei (AGN).
Filippo D'Ammando, Filippo D'Ammando
doaj +1 more source
Near Infrared Micro-variability of Radio-loud Quasars [PDF]
Publications of the Astronomical Society of Australia, 2002 AbstractWe observed three AGN from the Parkes Half-Jansky Flat-spectrum Sample at near infrared (NIR) wavelengths to search for micro-variability. In one source, the blue quasar PKS 2243–123, good evidence for NIR micro-variability was found. In the other two sources, PKS 2240–260 and PKS 2233–148, both BL Lacertae objects, no such evidence of ...
Whiting, Matthew +2 more
openaire +2 more sources
[C ii] Properties and Far-infrared Variability of a z = 7 Blazar
The Astrophysical Journal LettersWe present millimeter observations of the host galaxy of the most distant blazar known, VLASS J041009.05−013919.88 (hereafter J0410–0139) at z = 7, using Atacama Large Millimeter/submillimeter Array (ALMA) and NOrthern Extended Millimeter Array (NOEMA ...
Eduardo Bañados +9 more
doaj +1 more source
Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz
Universe, 2021 Two dozens of radio loud active galactic nuclei (AGNs) have been observed with Urumqi 25 m radio telescope in order to search for intra-day variability (IDV).
Xiang Liu +6 more
doaj +1 more source