VIII/108 Radio core dominance of Fermi/LAT-detected AGNs (Pei+, 2020)
Radio core dominance of Fermi/LAT-detected AGNs.
Pei Z-Y., Fan J.-H., Bastieri D., Yang J.-H., Xiao H.-B.
<Science China Physics, Mechanics and Astronomy, 63, 259511 (2020)>
=2020SCPMA..63y9511P 2020SCPMA..63y9511P
=2020yCat.8108....0P 2020yCat.8108....0P
ADC_Keywords: Active gal. nuclei ; QSOs ; Gamma rays
Keywords: active galactic nuclei (AGNs) - quasars - gamma-rays
Abstract:
We present a sample of 4388 AGNs with available radio core-dominance
parameters-defined as the ratio of the core flux densities to the
extended ones, R=Score/Sext. - which includes 630 Fermi-detected
AGNs from the fourth source catalog (4FGL) of the Fermi Large Area
Telescope (Fermi/LAT); the rest are non-Fermi-detected AGNs. In our
sample, 584 blazars are Fermi-detected and 1310 are not. The sample
also contains other subclasses, such as Seyferts, Fanaroff-Riley I/II
galaxies, and normal galaxies. We investigate various properties of
the Fermi-detected and non-Fermi-detected AGNs by using core-dominance
parameters, capitalizing on a previous study which showed that R is a
good indicator of beaming. We then calculate radio spectral indices
for the whole sample, and adopt γ-ray-photon indices for the
Fermi AGNs from the 4FGL catalog to discuss the properties of
different subclasses. We obtain a relation between the core-dominance
parameters and the radio spectral indices for both Fermi and non-Fermi
sources, assuming a two-component model in the radio band. Our
previous study ruled out the assumption that the core-dominance
parameters and radio spectral indices are quite different for
different AGN subclasses. This holds not only for Fermi sources but
also for non-Fermi sources. In particular, R is, on average, greater
for the former AGNs than for the latter. In this study, we enlarge our
sample with available values of R to 4388 AGNs, and the obtained
conclusions are consistent with our previous study. We assume that the
same two-component model holds for the γ-ray band as for the
radio band, and therefore, adopt the same relation between the
core-dominance parameters and the γ-ray-photon indices for Fermi
AGNs. Our fitting results indicate that the γ-ray emissions of
Fermi blazars originate mainly from the jet, and therefore, we
conclude that the Fermi blazars are beamed.
Description:
To obtain the available core-dominance parameters logR, we adopted the
data from Fan et al. (2011RAA....11.1413F 2011RAA....11.1413F), Pei et al.
(2019RAA....19...70P 2019RAA....19...70P, 2019 arXiv: 1909.06177).
Theses references include 1224, 2400, and 764 sources, respectively,
which constitute our total sample of 4388 AGNs.
The 630 FAGNs in our sample include 252 FBLLS, 283 FQs, 49 blazar of
uncertain class (FBCUs(, and 46 Fermi-detected AGNs (FAGNs) and the
remaining 3758 sources are non-Fermi detected sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 94 630 Sample of Fermi AGNs
table2.dat 54 3758 Sample of non-Fermi AGNs
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See also:
J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- 4FGL 4FGL name, 4FGL JHHMM.m+DDMMa
20- 39 A20 --- Name IAU Name
41- 44 A4 --- Class Classification (G1)
46- 53 F8.6 --- z Redshfit
55- 62 E8.3 1/cm2/s Flux Flux at 1GeV-100GeV
64- 67 F4.2 --- alphag γ-ray photon index
69- 73 F5.2 [-] logR Core-dominance parameter compiled from r_logR
75- 79 F5.2 [10-7W] logLg γ-ray luminosity
81- 85 F5.2 --- alphaR ? Radio spectral index
(Snu∝nu-alphaR)
87- 94 A8 --- r_logR Reference for logR (G2)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name IAU Name
20- 24 A5 --- Class Classification (G1)
26- 33 F8.6 --- z Redshfit
35- 39 F5.2 [-] logR Core-dominance parameter compiled from r_logR
41- 45 F5.2 --- alphaR ? Radio spectral index
(Snu∝nu-alphaR)
47- 54 A8 --- r_logR Reference for logR (G2)
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Global notes:
Note (G1): Classification as follows:
FBBL = Fermi BL Lacs
FQ = Fermi quasars
FBCU = Fermi blazars candidates of uncertain class
FNB = Fermi non-blazars
Note (G2): References as follows:
Fan11 = Fan et al., 2011RAA....11.1413F 2011RAA....11.1413F
Pei19(a) = Pei et al, 2019RAA....19...70P 2019RAA....19...70P, Cat. J/other/RAA/19.70
Pei19(b) = Pei et al, 2019, arXiv: 1909.06177
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Acknowledgements:
Zhiyuan Pei, zhiyuan.pei(at)studenti.unipd.it
(End) Patricia Vannier [CDS] 16-Oct-2020