Results 11 to 20 of about 10,418 (177)

Broad absorption line variability in radio-loud quasars [PDF]

Monthly Notices of the Royal Astronomical Society, 2014
We investigate C IV broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from SDSS/FIRST data to include both core-dominated (39) and lobe-dominated (7) objects. The sample consists primarily of high-ionization BAL quasars, and a substantial fraction have large BAL velocities or equivalent widths; their ...
Welling, C. A., Miller, B. P., Brandt, W. N., Capellupo, D. M., Gibson, R. R.   +4 more
openaire   +4 more sources

Radio-loud and radio-quiet quasars observed by EXOSAT [PDF]

Monthly Notices of the Royal Astronomical Society, 1992
We present results from the spectral analysis of EXOSAT data on 31 quasars, 18 radio-loud and 13 radio-quiet. Simple power-law models with fixed (Galactic) absorption give acceptable fits to the spectra obtained in the 2-10 keV band. Using the results from these fits we have compared the distributions of spectral indices α for the radio-loud and radio ...
A. J. Lawson, M. J. L. Turner, O. R. Williams, G. C. Stewart, R. D. Saxton   +4 more
openaire   +3 more sources

Radio-loudness Statistics of Quasars from Quaia-VLASS

The Astrophysical Journal Supplement Series
Quasars are objects of high interest in extragalactic astrophysics, cosmology, and astrometry. One of their useful qualities is their potential radio-loudness.
Nestor Arsenov, Sándor Frey, András Kovács, Lyuba Slavcheva-Mihova   +3 more
doaj   +3 more sources

Radio-loud Narrow-Line Type 1 Quasars [PDF]

The Astronomical Journal, 2006
We present the first systematic study of (non-radio-selected) radio-loud narrow-line Seyfert 1 (NLS1) galaxies. Cross-correlation of the `Catalogue of Quasars and Active Nuclei' with several radio and optical catalogues led to the identification of 11 ...
Antonucci R., Bade N., Bicay M. D., Blandford R., Blandford R., Boller T., Brinkmann W., Dawei Xu, Dirk Grupe, Elizalde F., Gerard Lemson, Grupe D., Hans-Martin Adorf, Jackson N., Joly M., Komossa S., Lawrence A., Leipski C., Mahalanobis P. C., Marecki A., Miller L., Miller P., Okuda T., Peacock J. P., Pounds K., Puchnarewicz E. M., Puchnarewicz E. M., Siebert J., Simkin M. V., Smita Mathur, Stefanie Komossa, Voges W., Wang J., Wang T. G., Wei J. Y., Whalen J., Wolfgang J. Duschl, Wolfgang Voges, Zheng Z.   +38 more
core   +4 more sources

The Central Engines of Radio-Loud Quasars [PDF]

Astronomy & Astrophysics, 2003
We have assembled a sample of 37 RLQs that have been imaged with the HST in order to investigate their black hole masses, accretion rates, and the structure of their accretion disks.
Abramowicz, Aldcroft, Bahcall, Baldwin, Baum, Baum, Baum, Begelman, Begelman, Bergeron, Bicknell, Blandford, Blandford, Blandford, Bogers, Boroson, Boroson, Boyce, Boyce, Brocksopp, Brotherton, Böttcher, Cao, Cavaliere, Celotti, Celotti, Chen, Chen, Chen, Corbin, Corbin, Danziger, Douglas, Dunlop, Eracleous, Falcke, Fanaroff, Fender, Francis, Fukugita, Ghisellini, Ghisellini, Ghisellini, Ghisellini, Ghosh, Gondhalekar, Grandi, Gregory, Gu, Hamilton, Harmon, Harmon, Ho, Ho, Hooper, Hooper, Hutchings, Hutchings, Iwasawa, J.-M. Wang, Jackson, Kellermann, Kollgaard, Kormendy, L. C. Ho, Lacy, Ledlow, Lister, Liu, Livio, Magorrian, Mahadevan, Malkan, Maraschi, Marscher, Marziani, McCollough, McLure, McLure, McLure, Meier, Meier, Nandra, Narayan, Narayan, Neugebauer, Ohsuga, Oke, Orr, Osmer, Owen, Phillips, Quataert, Quataert, R. Staubert, Rawlings, Rector, Rees, Reeves, Richstone, Rózanska, Sambruna, Scarpa, Shakura, Shields, Stockton, Urry, Urry, Wang, Wang, Wang, Wang, White, Wiita, Wilkes, Willott, Wills, Wilson, Xu, Zheng   +119 more
core   +2 more sources

Correlation between radio and broad-line emissions in radio-loud quasars [PDF]

Monthly Notices of the Royal Astronomical Society, 1999
Radio emission is a good indicator of the jet power of radio-loud quasars, while the emission in broad-line can well represent the accretion disc radiation in quasars. We compile a sample of all sources of which the broad-line fluxes are available from 1
Baker, Baldwin, Baldwin, Bergeron, Blandford, Blandford, Capetti, Celotti, Celotti, Corbin, Corbin, D. R. Jiang, di Serego Alighieri, Ellingson, Espey, Falcke, Falcke, Falcke, Francis, Fricke, Gelderman, Ghisellini, Hunstead, Jackson, Kinney, Kühr, Kühr, Lacy, Lawrence, Marziani, Neugebauer, Oke, Osmer, Pauliny Toth, Perez, Rawlings, Richstone, Rudy, Serjeant, Smith, Steiner, Stickel, Stickel, Stickel, Stickel, Stickel, Stickel, Stickel, Stickel, Stickel, Stiko, Stockton, Tadhunter, Vermeulen, Wampler, Wang, Warren, Wills, Wills, Xinwu Cao   +59 more
core   +5 more sources

The rest-frame ultraviolet properties of radio-loud broad absorption line quasars

Monthly Notices of the Royal Astronomical Society, 2012
We recently presented radio observations of a large sample of radio-loud broad absorption line (BAL) quasars from the SDSS and FIRST surveys, as well as a well matched sample of unabsorbed quasars, primarily to measure their radio spectral indices and ...
Allen, Antonucci, Becker, Becker, Becker, Boroson, Boroson, Brotherton, Brotherton, Bruni, Cano-Diaz, Condon, DiPompeo, DiPompeo, DiPompeo, DiPompeo, Elvis, Fanti, Fine, Gallagher, Ganguly, Ganguly, Ghosh, Gibson, Gregg, Gregg, Hall, Hewett, Hopkins, J. C. Runnoe, Jarvis, King, Knigge, Kriss, M. A. DiPompeo, M. S. Brotherton, Montenegro-Montes, Nemmen, O'Dea, Ogle, Peterson, Reichard, Richards, Richards, Runnoe, S. L. Cales, Schlegel, Shen, Silk, Spergel, Stocke, Vestergaard, Vestergaard, Weymann, Zhou   +54 more
core   +3 more sources

Radio Variability of Radio‐quiet and Radio‐loud Quasars [PDF]

The Astrophysical Journal, 2005
The majority of quasars are weak in their radio emission, with flux densities comparable to those in the optical, and energies far lower. A small fraction, about 10%, are hundreds to thousands of times stronger in the radio. Conventional wisdom holds that there are two classes of quasars, the radio quiets and radio louds, with a deficit of sources ...
Barvainis, R, Lehar, J, Birkinshaw, M, Falcke, H, Blundell, KM   +4 more
openaire   +2 more sources

Radio loudness along the quasar main sequence [PDF]

Astronomy & Astrophysics, 2019
Context.When can an active galactic nucleus (AGN) be considered radio loud (RL)? Following the established view of the AGNs inner workings, an AGN is RL if associated with relativistic ejections emitting a radio synchrotron spectrum (i.e., it is a “jetted” AGN). In this paper we exploit the AGN main sequence that offers a powerful tool to contextualize
Ganci V., Marziani P., D'Onofrio M., Del Olmo A., Bon E., Bon N., Negrete C. A.   +6 more
openaire   +5 more sources

Radio-loud flares from microquasars and radio-loudness of quasars [PDF]

Monthly Notices of the Royal Astronomical Society, 2005
5 pages, 3 figures.
NIPOTI, CARLO, Blundell K. M., Binney J.
openaire   +3 more sources