J/ApJS/268/23 Magnetic fields & emission regions of Fermi blazars (Fan+, 2023)
Characterizing the emission region properties of blazars.
Fan J., Xiao H., Yang W., Zhang L., Strigachev A.A., Bachev R.S., Yang J.
<Astrophys. J. Suppl. Ser., 268, 23 (2023)>
=2023ApJS..268...23F 2023ApJS..268...23F
ADC_Keywords: BL Lac objects; QSOs; Magnetic fields; Redshifts; Gamma rays
Keywords: Blazars ; Flat-spectrum radio quasars ; BL Lacertae objects ;
Jets ; Magnetic fields
Abstract:
Studies and constraints on the emission region are crucial to the
blazar radiation mechanism. Yet previous works have mainly focused on
individual sources. In this work, we make use of the largest and the
latest spectral energy distribution fitting results in the literature
to statistically study the blazar emission region properties in the
framework of a one-zone leptonic model. Our results reveal: (1) that
flat-spectrum radio quasars (FSRQs) show lower electron energy
(γp≲1.6x103) than BL Lacertae objects (BL Lacs) and tend to
have a stronger magnetic field (B) and smaller electron-to-magnetic
energy ratio (Ue/UB) than BL Lacs; (2) we find that the
electromagnetic equipartition would rather happen in the jets of BL
Lacs than happen in the jets of FSRQs; (3) there are 682 blazars with
a magnetic field weaker than the critical value for generating the
Kelvin-Helmholtz instability, thus one-third of the blazars in our
sample are able to produce this instability; and (4) the distance
(dem) between the emission region and the central black hole is on the
scale of ∼0.1pc, so the location of the emission region may be evenly
distributed inside and outside the broad-line region.
Description:
We collected a sample of Fermi blazars with the available synchrotron
peak frequency (logνsy) and corresponding luminosity (logLsy)
from Yang+ (2022, J/ApJS/262/18) and the IC peak frequency
(logνIC) and luminosity (logLIC) from Yang+ (2023SCPMA..6649511Y).
In total, we have 2708 sources, including 759 FSRQs, 1141 BL Lacs, and
808 blazar candidates of uncertain type (BCUs).
A distance (dem) from the SMBH to the emission region is obtained for
a subsample of 182 sources and used to discuss the emission region
location compare to the broad-line region (BLR).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 100 2708 The magnetic field strength and electron energy
for 2708 Fermi blazars
table2.dat 61 182 The location of the emission region for 182 blazars
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See also:
IX/67 : Incremental Fermi LAT 4th source cat. (4FGL-DR3) (Fermi-LAT col., 2022)
J/ApJ/609/539 : Kinematics of parsec-scale radio jets (Kellermann+, 2004)
J/other/ChJAA/8.385 : Superluminal motion in AGN (Zhang+, 2008)
J/AJ/138/1874 : MOJAVE. VI. Kinematics of blazar jets (Lister+, 2009)
J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)
J/other/RAA/13.259 : γ-ray Doppler factor for Fermi blazars (Fan+, 2013)
J/other/RAA/14.1135 : Doppler factor for a Fermi blazar sample (Fan+, 2014)
J/other/Nat/515.376 : Power of relativistic jets in blazars (Ghisellini+, 2014)
J/MNRAS/448/1060 : Fermi/LAT broad emission line blazars (Ghisellini+, 2015)
J/ApJ/810/L9 : 1.5Jy MOJAVE AGN sample and 3FGL data (Lister+, 2015)
J/ApJS/226/20 : X-ray, opt. & radio SEDs of Fermi blazars (Fan+, 2016)
J/ApJS/235/39 : Jet properties of γ-ray-loud 3FGL AGNs (Chen, 2018)
J/AJ/155/90 : 1996-2009 opt. phot. monitoring for 3C 66A (Fan+, 2018)
J/ApJ/866/137 : Bright blazars var. brightness temp. (Liodakis+, 2018)
J/A+A/623/A111 : 3C273 polarization over ALMA 1.3mm band (Hovatta+, 2019)
J/ApJ/874/43 : MOJAVE. XVII. pc-scale jet kinematics (Lister+, 2019)
J/ApJS/247/33 : Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
J/ApJS/253/10 : 12yrs of R-band phot. of the quasar 3C 454.3 (Fan+, 2021)
J/ApJ/923/30 : MOJAVE. XVIII. Radio-loud active AGNs (Lister+, 2021)
J/ApJS/253/46 : Optical spectroscopy of Fermi blazars (Paliya+, 2021)
J/ApJS/260/47 : 19.3yr R-band monitoring of 1ES 2344+514 (Cai+, 2022)
J/ApJ/925/97 : Fermi-LAT blazars fundamental parameters (Pei+, 2022)
J/ApJ/925/40 : Fermi blazar jet properties (Xiao+, 2022)
J/PASJ/74/239 : Radio dichotomy of active galactic nuclei (Xiao+, 2022)
J/ApJS/262/18 : SEDs for 4FGL blazars (Yang+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [4FGL]
6- 18 A13 --- 4FGL 4FGL catalog identifier (JHHMM.m+DDMMc)
20- 23 A4 --- Class1 Spectral classification
25- 27 A3 --- Class2 Classification from synchrotron peak
frequency (1)
29- 33 F5.3 --- z [0/4.31]? Redshift
from Yang+ 2022, J/ApJS/262/18
35- 39 F5.2 --- delta [0.2/88.5]? Doppler factor (2)
41- 44 F4.1 [Hz] lognusy [12/18.7] Log synchrotron peak frequency
(3)
46- 50 F5.2 [Hz] lognuIC [19.46/26.4] Log IC peak frequency (3)
52- 56 F5.2 --- P1 [-0.3/-0.04]? Spectral curvature (4)
58- 62 F5.2 [10-4T] logB [-5.41/5.01] Log magnetic field
strength; Gauss (5)
64- 68 F5.2 [10-4T] logB2 [-1.2/3.8]? Other limit in logB range (5)
70- 73 F4.2 [-] loggam [0.76/5.5] Log energy of electrons
contributing most to synchrotron peak (5)
75- 78 F4.2 [-] loggam2 [1/5]? Other limit value in loggam range
(5)
80- 85 F6.2 [10-7J/cm3] logUe [-11/19.4] Log energy density of the
electrons; erg/cm3 (5)
87- 91 F5.2 [10-7J/cm3] logUe2 [-9.2/10.1]? Other limit value in logUe
range (5)
93- 100 F8.2 [10-4T] Bc [0/29629]? Critical magnetic field
strength; Gauss
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Note (1): From Fan+ (2016, J/ApJS/226/20) and Yang+ (2022, J/ApJS/262/18)
Note (2): From Liodakis+ (2018, J/ApJ/866/137).
Note (3): From Yang+ (2022, J/ApJS/262/18 and 2023SCPMA..6649511Y).
Note (4): From Yang+ (2022, J/ApJS/262/18).
Note (5): If this and the following value are present, this represents the
range in the value. If only the first column is given, it represent
the parameter value.
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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- 4 A4 --- --- [4FGL]
6- 17 A12 --- 4FGL 4FGL catalog identifier (JHHMM.+DDMM)
19- 22 A4 --- Class1 Spectral classification
("BLL", 35 occurrences or
"FSRQ", 147 occurrences)
24- 31 F8.6 --- z [0.03/2.7] Redshift
33- 37 F5.2 --- delta [0.38/88.5]? Doppler factor (1)
39- 43 F5.2 deg theta [0.04/84.2] Viewing angle (1)
45- 49 F5.2 [cm] logdem [14.2/20] Estimated log distance (2)
51- 55 F5.2 [cm] logdemG15 [16/18]? Ghisellini & Tavecchio
2015, J/MNRAS/448/1060 log distance (2)
57- 61 F5.2 [10-7W] logLBLR [42.26/46.4]? Log Broad Line Region
luminosity; erg/s
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Note (1): From Liodakis+ (2018, J/ApJ/866/137).
Note (2): Between the emission region and the central black hole.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-Nov-2023