J/PASP/135/A4101 gamma-ray properties of FR-Is and BL Lacs (Ye+, 2023)
The beaming effect for Fermi-LAT-detected FR-I radio galaxies.
Ye X.-H., Zeng X.-T., Huang D.-Y., Zhang Z., Pei Z.-Y., Fan J.-H.
<Publ. Astron. Soc. Pac., 135, a4101 (2023)>
=2023PASP..135a4101Y 2023PASP..135a4101Y (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies, radio ; BL Lac objects ;
Gamma rays ; Redshifts
Keywords: active galactic nuclei - Fanaroff-Riley radio galaxies - gamma-rays -
jets
Abstract:
Our knowledge of Giga-electron volt (GeV) radio galaxies has been
revolutionized by the Fermi-LAT Telescope, which provides an excellent
opportunity to study the physical properties of GeV radio galaxies.
According to the radio power and morphology, radio galaxies can be
separated into Fanaroff-Riley Type I radio galaxies (FR-Is) and Type
II radio galaxies (FR-IIs). In this paper, we consider the unification
of FR-Is and BL Lacertae objects (BL Lacs), and assume FR-Is to be a
standard candle to discuss the beaming effect for Fermi-LAT-detected
FR-Is. Our main conclusions are as follows: (1) The estimated Doppler
factors for 30 Fermi-LAT-detected FR-Is are in a range of
δI=0.88-7.49. The average Doppler factor
(<δI≥2.56±0.30) of the 30 FR-Is is smaller than that
(<δBL≥10.28±2.03) of the 126 Fermi-LAT-detected BL Lacs,
supporting the unification model that FR-Is are regarded as the
misaligned BL Lacs with smaller Doppler factors; (2) We propose that
different regions of FR-Is in the plot of the {gamma|-ray luminosity
against the photon spectral index logLγ-αph_ may
indicate the different beaming effects; (3) The average Doppler factor
of the 6 TeV FR-Is is similar to that of the 24 non-TeV FR-Is, which
implies that the difference between the TeV and GeV emissions is not
driven by the beaming effect in the Fermi-LAT-detected FR-I samples.
Description:
Based on the catalog of 4FGL-DR2, 44 radio galaxies are detected by
Fermi-LAT (Abdollahi et al. 2020ApJS..247...33A 2020ApJS..247...33A, Cat. J/ApJS/247/33).
Subject to the FR-II samples, we only focused on the 30
Fermi-LAT-detected FR-Is and collected their redshifts from the
NASA/IPAC Extragalactic Database (NED) to estimate the Doppler factors
and discuss their beaming effect in the gamma-ray band. The
corresponding properties and derived results of the 30 FR-Is are
listed in Table 1.
By cross-checking the Doppler factors (Liodakis et al.,
2018ApJ...866..137L 2018ApJ...866..137L, Cat. J/ApJ/866/137; Zhang et al.,
2020ApJ...897...10Z 2020ApJ...897...10Z) and Fermi-LAT-detected BL Lacs (Abdollahi et al.,
2020ApJS..247...33A 2020ApJS..247...33A, Cat. J/ApJS/247/33), we compiled a sample of 126
Fermi-LAT-detected BL Lacs with available Doppler factors. The
detailed parameters for BL Lacs are listed in Table 2.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 72 30 The gamma-ray properties and derived results of
the 30 Fermi-LAT-detected FR-Is
table2.dat 57 126 The gamma-ray properties for the 126
Fermi-LAT-detected BL Lacs
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See also:
IX/67 : Incremental Fermi LAT 4th source cat. (4FGL-DR3)
(Fermi-LAT col., 2022)
J/ApJ/866/137 : Bright blazars variability brightness temp. (Liodakis+, 2018)
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+DDMM)
19- 32 A14 --- Name Other Name
34- 38 F5.3 --- z Redshift
40- 43 F4.2 --- alphaPh Photon spectral index
45- 50 F6.2 [mW/m2] logFg logarithm of the gamma-ray flux density
52- 56 F5.2 [10-7W] logLObsg logarithm of the observed gamma-ray
luminosity
58- 61 F4.2 --- deltag Doppler factor
63- 67 F5.2 --- B_deltag Possible maximum value of Doppler factor
69- 72 F4.2 --- b_deltag Possible minimum value of Doppler factor
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 4FGL 4FGL name (4FGL JHHMM.m+DDMM)
19- 23 F5.3 --- z Redshift
25- 28 F4.2 --- alphaPh Photon spectral index
30- 35 F6.2 [mW/m2] logFg logarithm of the gamma-ray flux density
37- 41 F5.2 [10-7W] logLgObs logarithm of the observed gamma-ray
luminosity
43- 47 F5.2 --- deltag Doppler factor
49- 51 A3 --- r_deltag Doppler factor references (1)
53- 57 F5.2 [10-7W] logLgIn logarithm of the gamma-ray intrinsic
luminosity
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Note (1): References as follows:
L18 = Liodakis et al. 2018ApJ...866..137L 2018ApJ...866..137L, Cat. J/ApJ/866/137
Z20 = Zhang et al., 2020ApJ...897...10Z 2020ApJ...897...10Z
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Apr-2023