Results 91 to 100 of about 382 (184)

Transient LoBALs at High Velocities: A Case of Extreme Broad Absorption Line Variability in J115636.82+085628.9

The Astrophysical Journal
We present a multiepoch spectroscopic study of the broad absorption line (BAL) quasar J115636.82+085628.9 ( z _em  = 2.1077), based on five spectra spanning nearly two decades in the observer’s frame.
P. Aromal, R. Srianand, S. C. Gallagher, M. Vivek, P. Petitjean   +4 more
doaj   +1 more source

Circumnuclear Gas of a Quasar in Absorption and Emission Lines

The Astrophysical Journal
We present a detailed analysis of the unusual absorption- and emission-line spectrum of the quasar SDSS J074850.39+442439.0 (hereafter J0748+4424) at a redshift of z = 2.18. The archival SDSS optical spectrum is abundant in narrow absorption lines (NALs)
Xuejie Dai, Lei Hao, Peng Jiang, Zhenzhen Li, Xiheng Shi, Shengmiao Wu, Yanfei Zou, Yipeng Zhou, Tuo Ji, Qiguo Tian, Bo Liu, Lin Lin, Hongyan Zhou   +12 more
doaj   +1 more source

QUEST: Quasar unsupervised encoder and synthesis tool

Astronomy & Astrophysics
Context. Quasars at the redshift frontier (z > 7.0) are fundamental probes of black hole growth and evolution, but are notoriously difficult to identify.
Guarneri F., Schindler J. T., Meyer R. A., Yang D., Hennawi J. F., Lucie-Smith L., Bosman S. E. I., Davies F. B.   +7 more
doaj   +1 more source

Tracing the massive inflows feeding super-massive black holes in quasars. [PDF]

Innovation (Camb), 2023
Jiang P, Shi X, Zhou H.
europepmc   +1 more source

Recurrent Multiyear Mg II Broad Absorption Line Variability in SDSS J1333+0012

The Astrophysical Journal
We present a long-term spectroscopic study of broad absorption line (BAL) variability in the quasar J1333+0012 ( z _em  = 0.9197) using an extensive multiepoch dataset spanning nearly two decades.
M. Vivek, P. Aromal, R. Srianand, K. A. Anjali, S. C. Gallagher, Rachana   +5 more
doaj   +1 more source

Indirect evidence of the 2175 Å extinction bump within the dusty torus of SDSS J141945.50+524648.0

Astronomy & Astrophysics
We present a multiwavelength study of the quasar SDSS J141945.50+524648.0 (z = 1.1599), a member of the newly identified population of quasar-associated 2175 Å dust absorbers.
Li Ze, Chen Gaoyang, Cui Qifan, Cai Zheng, Chen Jianzhen, Luo Zhijian, Shu Chenggang, Sun Fengwu, Xiao Hubing, Zhang Shaohua   +9 more
doaj   +1 more source

To Be Lensed or Not to Be Lensed: On the Nature of the Alleged High-z Lensed Quasars J0109–5424 and P170+20

The Astrophysical Journal
We present a detailed multiwavelength analysis of two gravitationally lensed z  > 6 quasar candidates: J0109–5424 and P170+20. Using JWST/NIRSpec near-infrared (NIR) data from the Aether survey, we demonstrate that J0109–5424 is in fact a FeLoBAL quasar ...
Aurora Mata-Sanchez, Emanuele Paolo Farina, Anniek J. Gloudemans, Debora Pelliccia, Roberto Decarli, Eduardo Bañados, Silvia Belladitta, Manuela Bischetti, Sarah E. I. Bosman, Xander Byrne, Thomas Connor, Frederick Davies, Thales A. Gutcke, Weizhe Liu, Chiara Mazzucchelli, Romain Meyer, Silvia Onorato, Fabian Walter, Feige Wang, Jinyi Yang   +19 more
doaj   +1 more source

Detection of an Extended Lyα Halo around a z = 6.64 Broad Absorption Line Quasar with the Keck Cosmic Web Imager

The Astrophysical Journal Letters
We present the first results from a program searching for extended Ly α halos around high-redshift ( z  ≳ 6.5) quasars using the red channel of the Keck Cosmic Web Imager (KCWI).
Raymond P. Remigio, Aaron J. Barth, Feige Wang, Jinyi Yang, Joseph F. Hennawi, Ryan J. Cooke, Eduardo Bañados, Xiaohui Fan, Emanuele Paolo Farina   +8 more
doaj   +1 more source

A Self-consistent Treatment of the Line-driving Radiation Force for Active Galactic Nuclei Outflows: New Prescriptions for Simulations

The Astrophysical Journal
Flows driven by photons have been studied for almost a century, and a quantitative description of the radiative forces on atoms and ions is important for understanding a wide variety of systems with outflows and accretion disks, such as active galactic ...
Aylecia S. Lattimer, Steven R. Cranmer
doaj   +1 more source

X-ray observations of broad absorption-line quasars

The Astrophysical Journal, 1984
The present 0.1-4 keV observer frame data was obtained for three broad absorption-line quasars with the imaging proportional counter on the Einstein Observatory. Data for one object, UM 232, are sufficiently good to tell that absorption at 1 keV is unimportant (quasar rest frame), which leads to an upper limit to the column density of absorbing gas of ...
openaire   +1 more source