A Comparison of the Centimetre-to-Submillimetre Continuum Spectra of BL Lacertae Objects and Flat Spectrum Radio Quasars

1994 ◽  
pp. 523-523
Author(s):  
J. A. Stevens ◽  
S. J. Litchfield ◽  
E. I. Robson ◽  
W. K. Gear ◽  
D. H. Hughes
Keyword(s):  
Bl Lacertae Objects ◽  
Bl Lacertae ◽  
Spectrum Radio

scholarly journals The De-beamed γ-Ray Emissions in Blazars

2013 ◽  
Vol 9 (S304) ◽  
pp. 159-160 ◽  
Author(s):  
J. H. Fan ◽  
Z. Y. Ji
Keyword(s):  
Flux Density ◽  
Strong Correlations ◽  
Bl Lacertae Objects ◽  
Present Sample ◽  
Bl Lacertae ◽  
Spectrum Radio ◽  
Γ Ray

AbstractBlazars (BL Lacertae objects and flat spectrum radio quasars) are strong γ-ray emitters, the γ-ray emissions are strongly beamed. In this work, we compiled a sample of Fermi blazars with available beaming factors, δR, to investigate the correlation between the γ-ray flux density, logfγ, and redshift, logz for the whole sample and the subclasses of the present sample. The analysis shows that there is no correlation between logfγ and logz for the observed γ-ray flux density, but there are strong correlations between the de-beamed flux densities, logfγdb and logz for the whole sample and the subclasses. Our results confirm that the γ-ray emissions are strongly beamed and imply that it is possible for one to use the radio beaming factor, δR for the beaming effect discussions in the γ-ray bands for Fermi blazars.

Correlation between Eddington Ratios and Broad-Line Luminosities in Flat-Spectrum Radio Quasars, BL Lacertae Objects, and Radio Galaxies

2007 ◽  
Vol 133 (5) ◽  
pp. 2187-2191 ◽  
Author(s):  
H. Dai ◽  
G. Z. Xie ◽  
S. B. Zhou ◽  
H. Z. Li ◽  
L. E. Chen ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
Broad Line ◽  
Bl Lacertae Objects ◽  
Bl Lacertae ◽  
Spectrum Radio

scholarly journals A Comparison of the Centimetre-to-Submillimetre Continuum Spectra of BL Lacertae Objects and Flat Spectrum Radio Quasars

1994 ◽  
Vol 159 ◽  
pp. 523-523
Author(s):  
J.A. Stevens ◽  
S.J. Litchfield ◽  
E.I. Robson ◽  
W. K. Gear ◽  
D.H. Hughes
Keyword(s):  
High Frequency ◽  
Spectral Shape ◽  
Continuum Emission ◽  
Frequency Range ◽  
Frequency Spectra ◽  
Bl Lacertae Objects ◽  
Bl Lacertae ◽  
Spectrum Radio ◽  
Bl Lacs ◽  
The Continuum

A comparison of the centimetre to submillimetre continuum spectra of 22 BL Lacertae objects and 24 flat-spectrum radio quasars (FSRQ) has been conducted in order to search for systematic differences between the two classes. The same overall spectral shape is found for all sources and it is concluded that the same basic physical model applies to the continuum emission over this frequency range in both cases. There is clear evidence, however, for the BL Lacs to have flatter high frequency spectra and this difference is reconciled with an intrinsic difference in the underlying jets of the two classes.

THE RELATIONSHIP AMONG XBLs, RBLs AND FSRQs

2010 ◽  
Vol 19 (06) ◽  
pp. 909-915
Author(s):  
HONG-GUANG WANG ◽  
JUN-HUI FAN ◽  
YONG HUANG ◽  
JING PAN ◽  
JIANG-HE YANG
Keyword(s):  
Black Hole ◽  
Emission Line ◽  
Central Black Hole ◽  
Bl Lacertae Objects ◽  
X Ray ◽  
Bolometric Luminosity ◽  
Bl Lacertae ◽  
Spectrum Radio ◽  
The Relationship ◽  
Black Hole Masses

In this work, we revisited the relationship between the subclasses of blazars (X–ray selected BL Lacertae objects (XBLs), radio selected BL Lacertae objects (RBLs), and flat spectrum radio quasars (FSRQs)) based on a sample of blazars. We found that the FSRQs–RBLs–XBLs relationship is clear in their bolometric luminosity, emission line luminosity and the accretion ratio with V FSRQs > V RBLs > V XBLs , where V stands for the three parameters. However, there is no clear difference amongst their central black hole masses. The bolometric luminosity is closely correlated with the emission line luminosity and the accretion ratio.

scholarly journals ROSAT Observations of Bright BL Lacertae Objects

1994 ◽  
Vol 159 ◽  
pp. 377-377
Author(s):  
G. Lamer ◽  
H. Brunner ◽  
R. Staubert
Keyword(s):  
Power Laws ◽  
Spectral Indices ◽  
Bl Lacertae Objects ◽  
Mean Values ◽  
X Ray ◽  
Bl Lacertae ◽  
Spectrum Radio ◽  
Significant Difference ◽  
The Mean ◽  
5 Ghz

We have compiled a sample of 23 X-ray and radio selected BL Lacertae objects which have been observed with the Position Sensitive Proportional Counter (PSPC) on board of the ROSAT Satellite. The sample consists of three parts:In Table I results from 4 objects observed for their known rapid X-ray variability are presented. 5 objects are the BL Lac subset of a complete sample of flat spectrum radio sources with 5 GHz flux densities > 1 Jy. Detailed results from this sample will be published in Brunner et al. 1993. The data of the 14 remainig objects were collected from the ROSAT data archive to supplement the sample. The whole sample contains 7 X-ray selected objects (XBLs,αOX < 1.2) and 16 radio selected objects (RBLs).The X-ray spectra of the sources are well described by single power laws with galactic absorption. The X-ray energy indices αX are widely dispersed around a mean of 1.34. Significant X-ray flux variability and correlated spectral variability was detected on timescales down to hours. The object H 1218+304 was found to be rapidly variable within each of three observations. Its spectral hardness is correlated with the flux level (see Table I).We calculated the intrinsic distributions of the spectral indices αX for the XBL and RBL samples and of the differences between ROSAT and EXOSAT ME spectral indices αPSPC – αME (only XBL sample) using a maximum likelihood fit. There is no significant difference in the mean spectral indices between the X-ray and radio selected subsamples. The mean values < αX > are 1.34 for XBLs and 1.33 for RBLs. The spectra of the X-ray selected objects slightly steepen at higher X-ray energies (< αPSPC – αME > = −0.11). This supports the view that the X-ray emission of XBLs is supplied by synchrotron radiation. The steepening of the X-ray spectrum is then due to a cutoff in the energy distribution of the electrons.

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