Results 11 to 20 of about 91,098 (240)

A Sample of Quasars with Strong Nitrogen Emission Lines from the Sloan Digital Sky Survey [PDF]

Astrophys.J.679:962-966,2008, 2008
We report on 293 quasars with strong NIV] lambda 1486 or NIII] lambda 1750 emission lines (rest-frame equivalent width > 3 \AA) at 1.7 < z < 4.0 selected from the Sloan Digital Sky Survey (SDSS) Fifth Data Release.
Fan, Xiaohui, Jiang, Linhua, Vestergaard, M.   +2 more
core   +3 more sources

On the link between associated MgII absorbers and star formation in quasar hosts [PDF]

, 2012
A few percent of quasars show strong associated MgII absorption, with velocities (v_off) lying within a few thousand km/s from the quasar systemic redshift.
Bahcall, Bergeron, Brice Ménard, Canalizo, Glikman, Hennawi, Ho, Hopkins, Hopkins, Richards, Richards, Schneider, Shen, Shen, Steidel, Tremaine, Urrutia, Vanden Berk, Vanden Berk, Veilleux, Wyithe, Yue Shen, Zhu   +22 more
core   +2 more sources

Predicting the Yields of z > 6.5 Quasar Surveys in the Era of Roman and Rubin [PDF]

The Astrophysical Journal, 2023
About 70 luminous quasars discovered at z > 6.5 are strongly biased toward the bright end, thus not providing a comprehensive view of quasar abundance beyond the cosmic dawn. We present the predicted results of the Roman/Rubin high-redshift quasar survey,
Wei Leong Tee, Xiaohui Fan, Feige Wang, Jinyi Yang, Sangeeta Malhotra, James E. Rhoads   +5 more
doaj   +2 more sources

The Small-Scale Environment of Quasars [PDF]

, 2006
Where do quasars reside? Are quasars located in environments similar to those of typical L* galaxies, and, if not, how do they differ? An answer to this question will help shed light on the triggering process of quasar activity.
Bahcall, Neta, Menard, Brice, Richards, Gordon, Serber, Will   +3 more
core   +1 more source

The Quasar-LBG Two-point Angular Cross-correlation Function at z ~ 4 in the COSMOS Field [PDF]

, 2015
In order to investigate the origin of quasars, we estimate the bias factor for low-luminosity quasars at high redshift for the first time. In this study, we use the two-point angular cross-correlation function (CCF) for both low-luminosity quasars at ...
Akiyama, M., Capak, P., Enoki, M., Ikeda, H., Kajisawa, M., Kashikawa, N., Koekemoer, A. M., Masters, D., Matsuoka, K., Miyaji, T., Morokuma, T., Nagao, T., Salvato, M., Sanders, D. B., Schinnerer, E., Scoville, N. Z., Shioya, Y., Taniguchi, Y.   +17 more
core   +3 more sources

Do Quasars Lens Quasars? [PDF]

, 1996
If the unexpectedly high frequency of quasar pairs with very different component redshifts is due to the lensing of a population of background quasars by the foreground quasar, typical lens masses must be $\sim10^{12}M_{\sun}$ and the sum of all such ...
Boyle B. J., Boyle B. J., Burbidge E. M., E. J. Wampler, Iovino A., Shaver P. A., Zitelli V.   +6 more
core   +2 more sources

Finding Multiply Lensed and Binary Quasars in the DESI Legacy Imaging Surveys

The Astrophysical Journal Supplement Series, 2023
The time delay between multiple images of strongly lensed quasars is a powerful tool for measuring the Hubble constant ( H _0 ). To achieve H _0 measurements with higher precision and accuracy using the time delay, it is crucial to expand the sample of ...
C. Dawes, C. Storfer, X. Huang, G. Aldering, Aleksandar Cikota, Arjun Dey, D. J. Schlegel   +6 more
doaj   +1 more source

The radio luminosity, black hole mass and Eddington ratio for quasars from the Sloan Digital Sky Survey [PDF]

, 2008
We investigate the $\mbh- \sigma_*$ relation for radio-loud quasars with redshift ...
Abazajian K, Akritas M G, Bonning E W, Boroson T A, Chen Hu, Dasyra K M, Drory N, Ferrarese L, Gebhardt K, Greene J E, Greene J E, Greene J E, Greene J E, Grupe D, Heckman T M, Ho L C, Ho L C, Kai Huang, Kaspi S, Kaspi S, Komossa S, Komossa S, Lacy M, Laor A, Laor A, Lauer T R, LaValley M P, Liu Y, Nelson C H, Netzer H, Onken C A, Peterson B M, Richards G T, Salviander S, Schneider D P, Shen J-J, Shields J C, Sikora M, Storey P J, Strittmatter P A, Terashima Y, Tremaine S, Treu T, Vanden B, Wang J M, Wang R, Wei-Hao Bian, Whalen D J, Woo J H, Woo J H, Xu C, Yan Xu, Yan-Mei Chen, Yuan F, Zhou H, Zhou H Y   +55 more
core   +1 more source

The X-Ray Properties of the Optically Brightest Mini-BAL Quasars from the Sloan Digital Sky Survey [PDF]

, 2010
We have compiled a sample of 14 of the optically brightest radio-quiet quasars ($m_{i}$~$\le$~17.5 and $z$~$\ge$~1.9) in the Sloan Digital Sky Survey Data Release 5 quasar catalog that have C IV mini-BALs present in their spectra.
Arav, Arnaud, Brandt, Brotherton, Chartas, Donald P. Schneider, Freeman, Gallagher, Ganguly, Gehan, Gibson, Gibson, Gibson, Gibson, Gordon P. Garmire, Hall, Hall, Hamann, Hewett, Jianfeng Wu, Just, Krolik, Lavalley, Lyons, M. L. Comins, Ohad Shemmer, Proga, Reichard, Robert R. Gibson, Schneider, Shemmer, Steffen, Strateva, Trump, Vignali, W. N. Brandt, White, York   +37 more
core   +2 more sources

Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XVIII. The Dark Matter Halo Mass of Quasars at z ∼ 6

The Astrophysical Journal, 2023
We present, for the first time, dark matter halo (DMH) mass measurement of quasars at z ∼ 6 based on a clustering analysis of 107 quasars. Spectroscopically identified quasars are homogeneously extracted from the Hyper Suprime-Cam Strategic Survey ...
Junya Arita, Nobunari Kashikawa, Yoshiki Matsuoka, Wanqiu He, Kei Ito, Yongming Liang, Rikako Ishimoto, Takehiro Yoshioka, Yoshihiro Takeda, Kazushi Iwasawa, Masafusa Onoue, Yoshiki Toba, Masatoshi Imanishi   +12 more
doaj   +1 more source