Results 101 to 110 of about 10,384 (186)

Optically Selected BL Lacertae Candidates from the Sloan Digital Sky Survey Data Release Seven

, 2009
We present a sample of 723 optically selected BL Lac candidates from the SDSS DR7 spectroscopic database encompassing 8250 deg^2 of sky; our sample constitutes one of the largest uniform BL Lac samples yet derived.
Anderson, S. F., Bahcall, N. A., Bizyaev, D., Brandt, W. N., Brewington, H., Diamond-Stanic, A. M., Fan, X., Hall, P. B., Kimball, A. E., Malanushenko, E., Malanushenko, V., Oravetz, D., Pan, K., Plotkin, Richard M., Richmond, M. W., Schneider, D. P., Shemmer, O., Simmonds, A., Snedden, S., Voges, W., York, D. G.   +20 more
core   +2 more sources

Quasar Clustering from SDSS DR5: Dependences on Physical Properties

, 2008
Using a homogenous sample of 38,208 quasars with a sky coverage of $4000 {\rm deg^2}$ drawn from the SDSS Data Release Five quasar catalog, we study the dependence of quasar clustering on luminosity, virial black hole mass, quasar color, and radio ...
Abazajian, Abazajian, Adelberger, Adelman-McCarthy, Andrew J. Connolly, Basilakos, Blanton, Coil, Cole, Constantin, Courteau, Croft, Croton, Daniel E. Vanden Berk, David H. Weinberg, Donald P. Schneider, Eisenstein, Fan, Ferrarese, Ferrarese, Francesco Shankar, Gao, Gebhardt, Gordon T. Richards, Gunn, Gunn, Haiman, Hennawi, Ho, Hogg, Hopkins, Hopkins, Hopkins, Hopkins, Jiang, Jing, Joseph F. Hennawi, King, Kollmeier, Kormendy, Lidz, Lupton, Magorrian, Martini, Michael A. Strauss, Mo, Myers, Myers, Myers, Myers, Neta A. Bahcall, Nicholas P. Ross, Padmanabhan, Padmanabhan, Patrick B. Hall, Pier, Reichard, Richards, Richards, Richards, Richstone, Robert J. Brunner, Ross, Schlegel, Schlegel, Schneider, Shankar, Shankar, Shen, Shen, Shen, Shen, Shen, Silk, Smith, Spergel, Stoughton, Tinker, Tremaine, Vestergaard, Wechsler, Wetzel, Wyithe, Wyithe, Wyithe, Xiaohui Fan, Yen-Ting Lin, York, Yue Shen, Zehavi, Zel'dovich   +90 more
core   +1 more source

Discovery of a Radio-loud/Radio-quiet Binary Quasar

The Astrophysical Journal, 1999
8 pages, 3 figures, to appear in Astrophysical Journal ...
Brotherton, M. S., Gregg, Michael D., Becker, R. H., Laurent-Muehleisen, S. A., White, R. L., Stanford, S. A.   +5 more
openaire   +2 more sources

First Measurements of Black Hole Accretion and Radio-jet Timescales in a Young Quasar at the Edge of Reionization

The Astrophysical Journal
We present the first study dedicated to measuring the timescales for black hole accretion and jet launching in a quasar at the edge of reionization, PSO J352.4034–15.3373 at z = 5.832 ± 0.001.
Sofía Rojas-Ruiz, Emmanuel Momjian, Frederick B. Davies, Eduardo Bañados, Anna-Christina Eilers, Sarah B. Bosman, Bhargav Vaidya, Chris Carilli, Chiara Mazzucchelli, Thomas Connor, Yana Khusanova   +10 more
doaj   +1 more source

The correlations between optical variability and physical parameters of quasars in SDSS Stripe 82

, 2012
We investigate the optical variability of 7658 quasars from SDSS Stripe 82. Taking advantage of a larger sample and relatively more data points for each quasar, we estimate variability amplitudes and divide the sample into small bins of redshift, rest ...
Ai, Ai, Aretxaga, Bauer, Bonoli, Butler, Cheng-Liang Jiao, Cid Fernandes, Courvoisier, Cristiani, Honma, Hook, Ivezić, Kato, Kawaguchi, Kollmeier, MacLeod, Manmoto, Meusinger, Netzer, Paltani, Paltani, Sakata, Schmidt, Schmidt, Schneider, Sesar, Shakura, Shen, Shen, Terlevich, Torricelli-Ciamponi, Trèvese, Trèvese, Vanden Berk, Vestergaard, Wenwen Zuo, White, Wilhite, Xue-Bing Wu, Yi-Qing Liu   +40 more
core   +1 more source

Quasar x-ray spectra revisited [PDF]

A sample of 45 quasars observed by the Imaging Proportional Counter (IPC) on the Einstein satellite is used to re-examine the relationship between the soft (0.2-3.5 keV) X-ray energy index and radio-loudness.
Elvis, M., Mcdowell, J., Shastri, P., Wilkes, B. J.   +3 more
core   +1 more source

Broad Absorption Line Quasars and the Radio‐Loud/Radio‐Quiet Dichotomy [PDF]

Publications of the Astronomical Society of the Pacific, 1999
The observation that the extremely broad, blueshifted absorption troughs which characterize broad absorption line quasars (BALQs) occur exclusively in radio-quiet quasars (RQQs) suggests that this class of active galactic nuclei (AGN) may offer important clues to the radio-loud/radio-quiet (RL/RQ) dichotomy in quasars.
openaire   +2 more sources

Investigating the Emission Mechanism in the Spatially Resolved Jets of Two z ≈ 3 Radio-loud Quasars

The Astrophysical Journal
This study focuses on high-redshift, z > 3, quasars where resolved X-ray jets remain underexplored in comparison to nearby sources. Building upon previous work, we identify and confirm extended kiloparsec-scale jets emission in two quasars (J1405+0415, z
Jaya Maithil, Daniel A. Schwartz, Aneta Siemiginowska, Preeti Kharb, Diana M. Worrall, John F. C. Wardle, Giulia Migliori, Chi C. Cheung, Bradford Snios, Doug B. Gobeille, Herman L. Marshall, Mark Birkinshaw   +11 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

Diverse Molecular Gas Excitations in Quasar Host Galaxies at z ∼ 6

The Astrophysical Journal
We present observations using the Northern Extended Millimetre Array (NOEMA) of CO and H _2 O emission lines and the underlying dust continuum in two quasars at z ∼ 6, i.e., P215−16 at z = 5.78 and J1429+5447 at z = 6.18.
Jianan Li, Ran Wang, Antonio Pensabene, Fabian Walter, Bram P. Venemans, Roberto Decarli, Eduardo Bañados, Pierre Cox, Roberto Neri, Alain Omont, Zheng Cai, Yana Khusanova, Fuxiang Xu, Dominik Riechers, Jeff Wagg, Yali Shao, Yuanqi Liu, Karl M. Menten, Qiong Li, Xiaohui Fan   +19 more
doaj   +1 more source