J/other/RAA/18.56 gamma-ray spectrum for Fermi blazars (Kang+, 2018)
On the intrinsic shape of the gamma-ray spectrum for Fermi blazars.
Kang S.-J., Wu Q., Zheng Y.-G., Yin Y., Song J.-L., Zou H., Feng J.-C.,
Dong A.-J., Wu Z.-Z., Zhang Z.-B., Wu L.-H.
<Res. Astron. Astrophys., 18, 56 (2018)>
=2018RAA....18...56K 2018RAA....18...56K (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; BL Lac objects ; Active gal. nuclei
Keywords: galaxies: active - galaxies: jets - gamma rays: galaxies -
galaxies: statistics
Abstract:
The curvature of the γ-ray spectrum in blazars may reflect the
intrinsic distribution of emitting electrons, which will further give
some information on the possible acceleration and cooling processes in
the emitting region. The γ-ray spectra of Fermi blazars are
normally fitted either by a single power-law (PL) or a log-normal
(call Logarithmic Parabola, LP) form. The possible reason for this
difference is not clear. We statistically explore this issue based on
the different observational properties of 1419 Fermi blazars in the
3LAC Clean Sample.We find that the γ-ray flux (100MeV-100GeV)
and variability index follow bimodal distributions for PL and LP
blazars, where the γ-ray flux and variability index show a
positive correlation. However, the distributions of γ-ray
luminosity and redshift follow a unimodal distribution. Our results
suggest that the bimodal distribution of γ-ray fluxes for LP and
PL blazars may not be intrinsic and all blazars may have an
intrinsically curved γ-ray spectrum, and the PL spectrum is just
caused by the fitting effect due to less photons.
Description:
The 3LAC Clean Sample lists 1444 γ-ray AGNs (Ackermann et al.
2015) with 414 FSRQs, 604 BL Lac objects, 402 BCU blazars and 24
non-blazar AGNs. We select 1419 Fermi blazars from the 3LAC Clean
Sample (3C 454.3, fitted with an exponentially cutoff power law, is
neglected). In this sample, the spectra of 130 sources are fitted with
LP and those of 1289 sources are fitted with PL.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 122 1419 Description of the Sample
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See also:
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/ApJ/744/177 : VLBA 5GHz observations of Fermi/LAT AGNs (Linford+, 2012)
J/ApJ/761/125 : X and gamma spectral indexes of Fermi blazars (Fan+, 2012)
J/ApJ/810/L9/ : 1.5Jy MOJAVE AGN sample and 3FGL data (Lister+, 2015)
J/other/RAA/16.13 : Sample of Fermi Blazars (Chen+, 2016)
J/A+A/588/A141 : The MWA view of Fermi blazars (Giroletti+, 2016)
J/A+A/591/A21 : Optical flux behaviour of Fermi blazars (Marchesini+, 2016)
J/A+A/602/A86 : Blazar candidates among Fermi/LAT 3FGL catalog
(Lefaucheur+, 217)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq Sequential number
6- 23 A18 --- 3FGL 3FGL name (3FGL JHHMM.m+DDMMa)
25- 31 A7 --- OClass Optical Classification (BL Lac, FSRQ, or BCUs)
34- 44 A11 --- SpType γ-ray spectral shape
(PowerLaw or LogParabola)
47- 57 E11.6 mW/m2 Sg γ-ray energy flux, from 100MeV to 100GeV
obtained by spectral fitting) from the 3FGL
(in erg/cm2/s)
59- 70 F12.6 --- VI Variability index
75- 82 F8.5 10-7W logLg ? γ-ray luminosity (in erg/s)
87-100 F14.10 [mW/m2] logSg log of γ-ray energy flux
102-113 F12.10 [-] logVI log of variability index
116-122 F7.5 --- z ? Redshift
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 11-Jul-2019