Results 101 to 110 of about 771 (176)

Radio Follow-up Observations of a Weak-line Quasar Exhibiting Remarkable X-Ray Variability

The Astrophysical Journal
SDSS J1539+3954 ( z  ≈ 1.935), a radio-quiet weak-line quasar (WLQ), exhibited exceptional X-ray variability in 2019–2020, with its X-ray flux increasing by over 20 times from 2013 to 2019 and subsequently dropping by at least a factor of 9 in 2020 ...
Ayushi Chhipa, M. Vivek, Nayana A. J., P. Kharb, W. N. Brandt, Preshanth Jagannathan, Janhavi Baghel, Savithri H. Ezhikode, C. H. Ishwara-Chandra   +8 more
doaj   +1 more source

Do All the Quasars and High-excitation Radio Galaxies (HERGs) in the 3CRR Catalog Contain a Magnetically Arrested Disk (MAD)?

The Astrophysical Journal
Based on the magnetization, an accretion disk with a large-scale magnetic field can be separated into either standard and normal evolution or magnetically arrested disk (MAD), which are difficult to identify from observations. It is still unclear whether
Shuang-Liang Li, Wenwen Zuo, Xinwu Cao
doaj   +1 more source

[O II] Emission, Eigenvector 1, and Orientation in Radio-quiet Quasars

, 2017
We present supportive evidence that the Boroson & Green eigenvector 1 is not driven by source orientation and further that both [O III] λ5007 and [O II] λ3727 are isotropically emitted in the radio-quiet sample of bright quasar survey (BQS) quasars ...
Wilkes, Belinda, Brandt, W. N., Vestergaard, M., Kuraszkiewicz, Joanna   +3 more
core   +1 more source

The X-ray properties of the most luminous quasars with strong emission-line outflows

Astronomy & Astrophysics
Context. Strong outflows from active galactic nuclei are frequently observed in objects with lower coronal X-ray luminosity. This intrinsic X-ray weakness is considered a requirement for the formation of radiatively driven winds. Aims.
Shlentsova Anastasia, Trefoloni Bartolomeo, Signorini Matilde, Risaliti Guido, Lusso Elisabeta, Nardini Emanuele, Bauer Franz E., Temple Matthew J., Rankine Amy L., Richards Gordon T.   +9 more
doaj   +1 more source

JWST Q3D Program: Active Galactic Nucleus Photoionization and Shock Ionization in a Red Quasar at z = 0.4

The Astrophysical Journal
Red quasars, often associated with potent [O iii ] outflows on both galactic and circumgalactic scales, may play a pivotal role in galactic evolution and black hole feedback. In this work, we explore the [Fe ii ] emission in one such quasar at z = 0.4352–
Swetha Sankar, Nadia L. Zakamska, David S. N. Rupke, Weizhe Liu, Dominika Wylezalek, Sylvain Veilleux, Caroline Bertemes, Nadiia Diachenko, Yu-Ching Chen, Yuzo Ishikawa, Andrey Vayner, Nicole P. H. Nesvadba, Guilin Liu, Andy D. Goulding, Dieter Lutz   +14 more
doaj   +1 more source

Evidence for quasar fast outflows being accelerated at the scale of tens of parsecs. [PDF]

Sci Adv, 2022
He Z, Liu G, Wang T, Mou G, Green R, Bian W, Wang H, Ho LC, Sun M, Shen L, Arav N, Chen C, Wu Q, Guo H, Lin Z, Li J, Yi W.   +16 more
europepmc   +1 more source

Windy or Not: Radio Parsec-scale Evidence for a Broad-line Region Wind in Radio-quiet Quasars

The Astrophysical Journal
Does a broad-line region (BLR) wind in radio-quiet (RQ) active galactic nuclei (AGN) extend to parsec scales and produce radio emission? We explore the correlations between a parsec-scale radio wind and the BLR wind in a sample of 19 RQ Palomar–Green ...
Sina Chen, Ari Laor, Ehud Behar, Ranieri D. Baldi, Joseph D. Gelfand, Amy E. Kimball, Ian M. McHardy, Gabor Orosz, Zsolt Paragi   +8 more
doaj   +1 more source

UEG Week 2025 Oral Presentations

United European Gastroenterology Journal, Volume 13, Issue S8, Page S7-S188, October 2025.
wiley   +1 more source

Double Lobed Radio Quasars from the Sloan Digital Sky Survey [PDF]

, 2005
We have combined a sample of 44 984 quasars, selected from the Sloan Digital Sky Survey (SDSS) Data Release 3, with the FIRST radio survey. Using a novel technique where the optical quasar position is matched to the complete radio environment within 450''
de Vries, W. H., R. L. White, Becker, R. H., W. H. de Vries, R. H. Becker, White, R. L.   +5 more
core   +1 more source

Intra-night Optical Variability and Radio Characteristics of Extremely Radio-loud Narrow-line Seyfert 1 Galaxies

The Astrophysical Journal
Narrow-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, Parveen Kumar, Avik Kumar Das, Vineet Ojha   +3 more
doaj   +1 more source