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.

scholarly journals Classification of blazar candidates of uncertain type from the Fermi LAT 8-yr source catalogue with an artificial neural network

2020 ◽  
Vol 493 (2) ◽  
pp. 1926-1935 ◽  
Author(s):  
M Kovačević ◽  
G Chiaro ◽  
S Cutini ◽  
G Tosti
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Supervised Machine Learning ◽  
Large Area ◽  
Bl Lacertae ◽  
Spectrum Radio ◽  
Γ Ray ◽  
Artificial Neural ◽  
Bl Lacs

ABSTRACT The Fermi Large Area Telescope (LAT) has detected more than 5000 γ-ray sources in its first 8 yr of operation. More than 3000 of them are blazars. About 60 per cent of the Fermi-LAT blazars are classified as BL Lacertae objects (BL Lacs) or Flat Spectrum Radio Quasars (FSRQs), while the rest remain of uncertain type. The goal of this study was to classify those blazars of uncertain type, using a supervised machine learning method based on an artificial neural network, by comparing their properties to those of known γ-ray sources. Probabilities for each of 1329 uncertain blazars to be a BL Lac or FSRQ are obtained. Using 90 per cent precision metric, 801 can be classified as BL Lacs and 406 as FSRQs while 122 still remain unclassified. This approach is of interest because it gives a fast preliminary classification of uncertain blazars. We also explored how different selections of training and testing samples affect the classification and discuss the meaning of network outputs.

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.

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