Results 51 to 60 of about 10,418 (177)

X-rays from a radio-loud compact BAL Quasar 1045+352 and the nature of outflows in radio-loud BAL Quasars

, 2009
We present new results on X-ray properties of radio loud broad absorption line (BAL) quasars and focus on broad-band spectral properties of a high ionization BAL (HiBAL) compact steep spectrum (CSS) radio-loud quasar 1045+352.
Agnieszka Janiuk, Aneta Siemiginowska, Bechtold, Becker, Brotherton, Brotherton, Crusius, Czerny, Elvis, Gallagher, Gallagher, Ganguly, Ghisellini, Ghosh, Ghosh, Green, Gregg, Gregg, Hatziminaoglou, Hewett, Hirose, Janiuk, Janiuk, Kardashev, Krzysztof Katarzyński, Kunert-Bajraszewska, Magdalena Kunert-Bajraszewska, Miller, Miller, Proga, Reynolds, Schaefer, Shen, Siemiginowska, Sobolewska, Sobolewska, Stawarz, Turner, Wang, White, Wills, Wills, Witt, Young, Zhou   +44 more
core   +1 more source

The host galaxies of three radio-loud quasars: 3C 48, 3C 345, and B2 1425+267 [PDF]

, 1999
Observations with the Wide-Field/Planetary Camera-2 of the Hubble Space Telescope (HST) are presented for three radio-loud quasars: 3C 48 (z=0.367), B2 1425+267 (z=0.366), and 3C 345 (z=0.594).
Akujor C. E., Donald P. Schneider, Dunlop J. S., Fanti C., Jerome Kristian, John N. Bahcall, Kotilainen J. K., Matthews T. A., McLeod K. K., Rogola A., Schraml J., Sofia Kirhakos, Taylor G. L., Veron-Cetty M. P.   +13 more
core   +2 more sources

Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission [PDF]

, 2015
We investigate the evolution of both the radio-loud fraction (RLF) and (using stacking analysis) the mean radio-loudness of quasars. We consider how these values evolve as a function of redshift and luminosity, black hole (BH) mass and accretion rate ...
Kratzer, Rachael M., Richards, Gordon T.
core   +1 more source

Varstrometry for Off-nucleus and Dual Sub-kiloparsec Active Galactic Nuclei (VODKA): Very Long Baseline Array Searches for Dual or Off-nucleus Quasars and Small-scale Jets

The Astrophysical Journal, 2023
Dual and off-nucleus active supermassive black holes are expected to be common in the hierarchical structure formation paradigm, but their identification at parsec scales remains a challenge due to strict angular resolution requirements.
Yu-Ching Chen, Xin Liu, Joseph Lazio, Peter Breiding, Sarah Burke-Spolaor, Hsiang-Chih Hwang, Yue Shen, Nadia L. Zakamska   +7 more
doaj   +1 more source

Prospects for Observing High-redshift Radio-loud Quasars in the SKA Era: Paving the Way for 21 cm Forest Observations

The Astrophysical Journal
The 21 cm forest is a sensitive probe for the early heating process and small-scale structures during the epoch of reionization (EOR), to be realized with the upcoming Square Kilometre Array (SKA). Its detection relies on the availability of radio-bright
Qi Niu, Yichao Li, Yidong Xu, Hong Guo, Xin Zhang   +4 more
doaj   +1 more source

Cross‐Polarization Gain Calibration of Linearly Polarized VLBI Antennas by Observations of 4C 39.25

Radio Science, Volume 59, Issue 4, April 2024.
Abstract Radio telescopes with dual linearly polarized feeds regularly participate in Very Long Baseline Interferometry. One example is the VLBI Global Observing System (VGOS), which is employed for high‐precision geodesy and astrometry. In order to achieve the maximum signal‐to‐noise ratio, the visibilities of all four polarization products are ...
F. Jaron, I. Martí‐Vidal, M. Schartner, J. González‐García, E. Albentosa‐Ruiz, S. Bernhart, J. Böhm, J. Gruber, S. Modiri, A. Nothnagel, V. Pérez‐Díez, T. Savolainen, B. Soja, E. Varenius, M. H. Xu   +14 more
wiley   +1 more source

The Radio‐Loud Narrow‐Line Quasar SDSS J172206.03+565451.6

The Astrophysical Journal, 2006
We report identification of the radio loud narrow-line quasar SDSS J172206.03+565451.6 which we found in the course of a search for radio loud narrow-line Active Galactic Nuclei (AGN). SDSSJ172206.03+565451.6 is only the ~4th securely identified radio loud narrow-line quasar and the second-most radio loudest with a radio index R_1.4 ~ 100-700.
Komossa, S., Voges, W., Adorf, H., Xu, D., Mathur, S., Anderson, S.   +5 more
openaire   +3 more sources

The optical variability of radio-loud quasars [PDF]

Proceedings of the International Astronomical Union, 2012
AbstractThe optical variability of a sample of 44 FSRQs and 18 SSRQs in the SDSS stripe 82 region is investigated by using the multi-epoch data covering nine years. The variabilities are clearly detected in each source with the amplitude in r band, from 0.18 to 3.46 mag.
Minfeng Gu, Y. L. Ai
openaire   +1 more source

A Surprising Excess of Radio Emission in Extremely Stable Quasars: A Unique Clue to Jet Launching?

The Astrophysical Journal
Quasars are generally divided into jetted radio-loud and nonjetted radio-quiet ones, but why only 10% of quasars are radio-loud has been puzzling for decades.
Wen-Yong Kang, Jun-Xian Wang, Zhen-Yi Cai, Hao-Chen Wang, Wen-Ke Ren, Mai Liao, Feng Yuan, Andrzej Zdziarski, Xinwu Cao   +8 more
doaj   +1 more source

The EMSS Radio Loud Quasar Sample

, 2000
We construct the first X-ray selected sample of radio-loud quasars from the EMSS survey. The X-ray selection allows us to explore the properties of radio-loud quasars 10-100 weaker than classical samples in the radio band. There are no radio-loud quasars whose synchrotron peak reaches the UV-soft X-ray band at these (radio) flux levels (as occurs for ...
Wolter, Anna, Celotti, Annalisa
openaire   +2 more sources