Results 111 to 120 of about 2,405 (218)

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

The Physical Driver of the Optical Eigenvector 1 in Quasar Main Sequence

Frontiers in Astronomy and Space Sciences, 2017
Quasars are complex sources, characterized by broad band spectra from radio through optical to X-ray band, with numerous emission and absorption features. This complexity leads to rich diagnostics.
Swayamtrupta Panda, Swayamtrupta Panda, Bożena Czerny, Bożena Czerny, Conor Wildy   +4 more
doaj   +1 more source

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

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

Discovery of spectacular quasar-driven superbubbles in red quasars. [PDF]

Sci Adv, 2023
Shen L, Liu G, He Z, Zakamska NL, Glikman E, Greene JE, Hu W, Mou G, Wylezalek D, Rupke DSN.   +9 more
europepmc   +1 more source

BROAD ABSORPTION LINE DISAPPEARANCE ON MULTI-YEAR TIMESCALES IN A LARGE QUASAR SAMPLE

, 2012
We present 21 examples of CIV broad absorption line (BAL) trough disappearance in 19 quasars selected from systematic multi-epoch observations of 582 bright BAL quasars (1.9 We present 21 examples of C IV broad absorption line (BAL) trough disappearance ...
Ross, Nicholas P., Petitjean, P., Brandt, W. N., Bizyaev, D., Oravetz, D. J., Filiz Ak, N., Lundgren, B. F., Malanushenko, E., Shen, Yue, York, D. G., Gibson, R. R., Ak, Nurten, Hall, P. B., Simmons, A. E., Schneider, D. P., Pan, K., Brinkmann, J., Weaver, B. A., Anderson, S. F., Myers, A. D.   +19 more
core   +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

Molecular Outflow in the Reionization-epoch Quasar J2054-0005 Revealed by OH 119 μm Observations

The Astrophysical Journal
Molecular outflows are expected to play a key role in galaxy evolution at high redshift. To study the impact of outflows on star formation at the epoch of reionization, we performed sensitive Atacama Large Millimeter/submillimeter Array observations of ...
Dragan Salak, Takuya Hashimoto, Akio K. Inoue, Tom J. L. C. Bakx, Darko Donevski, Yoichi Tamura, Yuma Sugahara, Nario Kuno, Yusuke Miyamoto, Seiji Fujimoto, Suphakorn Suphapolthaworn   +10 more
doaj   +1 more source

Reorienting Our Perspective of Broad Absorption Line Quasars

, 2012
Proceedings from the conference "AGN Winds in Charleston", October ...
DiPompeo, Michael A., Brotherton, Michael S., De Breuck, Carlos, Laurent-Muehleisen, Sally   +3 more
openaire   +2 more sources