Results 21 to 30 of about 10,418 (177)

The Environments of Radio-Loud Quasars [PDF]

, 2001
6 pages, 4 figures, to appear in the proc.
Barr, J. M., Bremer, M. N., Baker, J. C.
openaire   +2 more sources

The Pan-STARRS1 z > 5.6 Quasar Survey. II. Discovery of 55 Quasars at 5.6 < z < 6.5

The Astrophysical Journal Supplement Series, 2023
The identification of bright quasars at z ≳ 6 enables detailed studies of supermassive black holes, massive galaxies, structure formation, and the state of the intergalactic medium within the first billion years after the Big Bang.
Eduardo Bañados, Jan-Torge Schindler, Bram P. Venemans, Thomas Connor, Roberto Decarli, Emanuele Paolo Farina, Chiara Mazzucchelli, Romain A. Meyer, Daniel Stern, Fabian Walter, Xiaohui Fan, Joseph F. Hennawi, Yana Khusanova, Nidia Morrell, Riccardo Nanni, Gaël Noirot, Antonio Pensabene, Hans-Walter Rix, Joseph Simon, Gijs A. Verdoes Kleijn, Zhang-Liang Xie, Da-Ming Yang, Andrew Connor   +22 more
doaj   +1 more source

Spectral Variability in Radio-Loud Quasars [PDF]

Journal of Astrophysics and Astronomy, 2014
5 pages, 3 figures, accepted to JApA, conference proceeding paper for Variability of Blazars - From Jansky to Fermi (VBJF), Dec.
openaire   +2 more sources

Near Infrared Micro-variability of Radio-loud Quasars [PDF]

Publications of the Astronomical Society of Australia, 2002
AbstractWe observed three AGN from the Parkes Half-Jansky Flat-spectrum Sample at near infrared (NIR) wavelengths to search for micro-variability. In one source, the blue quasar PKS 2243–123, good evidence for NIR micro-variability was found. In the other two sources, PKS 2240–260 and PKS 2233–148, both BL Lacertae objects, no such evidence of ...
Whiting, Matthew, Oshlack, Alicia, Webster, Rachel   +2 more
openaire   +2 more sources

Radio Properties of z>4 Optically-Selected Quasars [PDF]

, 2000
We report on two programs to address differential evolution between the radio-loud and radio-quiet quasar populations at high (z>4) redshift. Both programs entail studying the radio properties of optically-selected quasars.
Daniel Stern, Goldschmidt P., Hook I. M., J. V. Wall, McMahon R. G., Miller L., Miller P., Peacock J. A., R. A. Perley, Reinaldo R. de Carvalho, S. G. Djorgovski, Shaver P. A., Zickgraf F.-J.   +12 more
core   +2 more sources

The jet-disc connection: evidence for a reinterpretation in radio loud and radio quiet active galactic nuclei [PDF]

, 2013
To constrain models of the jet-disc connection, we explore Eddington ratios reported in Foschini (2011) and interpret them in relation to the values in Sikora et al.
Garofalo, David
core   +3 more sources

Faint radio-loud quasars: clues to their evolution [PDF]

Monthly Notices of the Royal Astronomical Society, 2005
The quasar sample selected by cross-correlating the FIRST and the 2dF Quasar Redshift Surveys allows us to explore, for the first time, the faint end of the radio and optical luminosity functions up to z = 2.2. We find indications (~3 ) of a negative evolution for these faint sources at z > 1.8, both in radio and optical bands. This corresponds to
CIRASUOLO M., MAGLIOCCHETTI M., Celotti, Anna Lisa   +2 more
openaire   +2 more sources

3C 57 as an atypical radio-loud quasar: implications for the radio-loud/radio-quiet dichotomy [PDF]

Monthly Notices of the Royal Astronomical Society, 2015
Accepted for publication in MNRAS; 10 pages, 6 figures, 4 ...
Sulentic, J. W., Martínez-Carballo, M. A., MARZIANI, Paola, del Olmo, A., STIRPE, Giovanna Maria, Zamfir, S., Plauchu-Frayn, I.   +6 more
openaire   +5 more sources

Blazars in the early Universe [PDF]

, 2011
We investigate the relative occurrence of radio--loud and radio-quiet quasars in the first billion years of the Universe, powered by black holes heavier than one billion solar masses. We consider the sample of high-redshfit blazars detected in the hard X-
Abdo, Ajello, Baes, Becker, Bernardi, Bryan, Croton, F. Haardt, Ferrarese, G. Ghisellini, Ghisellini, Ghisellini, Ghisellini, Gültekin, Haiman, Hook, Hopkins, Häring, Jiang, Kormendy, Kormendy, Kurk, Lauer, Lauer, M. Volonteri, Marconi, Marconi, McGreer, Merloni, Pizzella, R. Della Ceca, Rhook, Richards, Richards, Romani, Schneider, Shakura, Shen, Sheth, Treister, Tremaine, Tundo, Volonteri, Volonteri, Willott, Worsley, Worsley, Wyithe, Yuan   +48 more
core   +1 more source

Intranight optical variability of BL Lacs, radio-quiet quasars and radio-loud quasars [PDF]

Monthly Notices of the Royal Astronomical Society, 2005
8 pages, 3 Postscript figures, Accepted for publication in MNRAS, uses mn2e ...
Stalin, C. S., Gupta, A. C., Gopal-Krishna, Wiita, P. J., Sagar, R.   +4 more
openaire   +2 more sources