Results 191 to 200 of about 1,444 (209)

Classification Of Flat Spectrum Radio Quasars By Optical Activity Types

Astrophysics
We have carried out a spectral classification by the activity types for a subsample of blazars from the BZCAT v.5 Catalogue, namely the Flat Spectrum Radio Quasars (FSRQ) candidates, designated in the catalogue as BZQ subtype objects. The classification is based on the Sloan Digital Sky Survey (SDSS) homogeneous medium-resolution optical spectroscopy ...
A. M. Mickaelian, H. V. Abrahamyan, G. M. Paronyan, G. A. Mikayelyan, A. G. Sukiasyan, V. K. Mkrtchyan   +5 more
openaire   +1 more source

Search for the shortest variability at gamma rays in flat-spectrum radio quasars

Astronomy and Astrophysics, 2011
We report about the search for short-term variability in the high-energy γ-ray energy band of three flat-spectrum radio quasars (3C 454.3, 3C 273, PKS B1222 + 216), whose flux at E > 100 MeV exceeded the value of 10-5 ph cm-2 s-1 for at least one day ...
L Foschini, F Tavecchio, G Bonnoli
exaly   +2 more sources

The Scale Invariant Synchrotron Jet of Flat Spectrum Radio Quasars

Journal of Astrophysics and Astronomy, 2015
In this paper, the scale invariance of the synchrotron jet of Flat Spectrum Radio Quasars has been studied using a sample of combined sources from FKM04 and from SDSS DR3 catalogue. Since the research of scale invariance has been focused on sub-Eddington cases that can be fitted onto the fundamental plane, while near-Eddington sources such as FSRQs ...
L. M. Du, J. M. Bai, Z. H. Xie, T. F. Yi, Y. B. Xu, R. Xue, X. H. Wang   +6 more
openaire   +1 more source

The optical variability properties of flat spectrum radio quasar 3C 454.3

New Astronomy, 2015
Abstract The optical variability and property of color index of the flat spectrum radio quasar object 3C 454.3 have been studied. The source exhibits strong variability both in intraday and long-term timescale. The χ 2 test suggests that 171 out of 285 nights in R band present intraday variability, and the typical intraday timescale is
Yao Zhou, Da-Hai Yan, Ben-Zhong Dai
openaire   +1 more source

Multiwavelength study of the quiescent states of six brightest flat-spectrum radio quasars detected by Fermi-LAT

Monthly Notices of the Royal Astronomical Society, 2021
Abhradeep Roy, S R Patel, A Sarkar
exaly  

The dichotomy between low-frequency-peaked BL Lacs and flat-spectrum radio quasars

Monthly Notices of the Royal Astronomical Society, 2022
Y P Cheng, S J Kang, Y G Zheng
exaly  

Spectral Energy Distribution of Flat-Spectrum Radio Quasars observedwith bepposax

2002
cfr.
Tavecchio F., Maraschi L., Ghisellini G., Celotti A., Chiappetti L., Comastri A., Fossati G., Grandi P., Pian E., Tagliaferri G. Treves A., Sambruna R.   +10 more
openaire   +1 more source

Is there a relationship between BL Lacertae objects and flat-spectrum radio quasars?

Monthly Notices of the Royal Astronomical Society, 1992
P Padovani, Padovani P
exaly  

Locating the gamma-ray emission region in the brightestFermi-LAT flat-spectrum radio quasars

Monthly Notices of the Royal Astronomical Society, 2020
A Acharyya, Paula M Chadwick, Anthony M Brown   +2 more
exaly  

A survey for high-redshift radio-loud quasars: optical spectroscopy of S > 0.2 Jy, flat-spectrum radio sources

Monthly Notices of the Royal Astronomical Society, 1996
I M Hook, R G Mcmahon, C Hazard
exaly