J/ApJ/866/137 Bright blazars variability brightness temp. (Liodakis+, 2018)
Constraining the limiting brightness temperature and Doppler factors for the
largest sample of radio bright blazars.
Liodakis I., Hovatta T., Huppenkothen D., Kiehlmann S., Max-Moerbeck W.,
ReadheadA A.C.S.
<Astrophys. J. 866, 137 (2018)>
=2018ApJ...866..137L 2018ApJ...866..137L (SIMBAD/NED BibCode)
ADC_Keywords: BL Lac objects ; Active gal. nuclei ; QSOs
Keywords: galaxies: active - galaxies: jets - relativistic processes
Abstract:
Relativistic effects dominate the emission of blazar jets complicating
our understanding of their intrinsic properties. Although many methods
have been proposed to account for them, the variability Doppler factor
method has been shown to describe the blazar populations best. We use
a Bayesian hierarchical code called Magnetron to model the light
curves of 973 sources observed by the Owens Valley Radio Observatory's
40-m telescope as a series of flares with an exponential rise and
decay, and estimate their variability brightness temperature. Our
analysis allows us to place the most stringent constraints on the
equipartition brightness temperature i.e., the maximum achieved
intrinsic brightness temperature in beamed sources which we found to
be <T_{eq}≥2.78x1011K±26%. Using our findings we estimated the
variability Doppler factor for the largest sample of blazars
increasing the number of available estimates in the literature by
almost an order of magnitude. Our results clearly show that
γ-ray loud sources have faster and higher amplitude flares than
γ-ray quiet sources. As a consequence they show higher
variability brightness temperatures and thus are more relativistically
beamed, with all of the above suggesting a strong connection between
the radio flaring properties of the jet and γ-ray emission.
Description:
Variability brightness temperature and Doppler factors for sources
monitored by the 40-m radio telescope at the Owens Valley Radio
Observatory with a redshift estimate (table2.dat).
Variability brightness temperature and Doppler factors for sources
monitored by the 40-m radio telescope at the Owens Valley Radio
Observatory without a redshift estimate (table3.dat).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 116 878 Variability brightness temperatures and beaming
properties for the sources in our sample
(Tvar and deltavar for bright blazars)
table3.dat 73 151 Variability brightness temperatures and beaming
properties for the sources in our sample
without a redshift estimate
(Tvar and deltavar for bright blazars)
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See also:
J/AJ/152/12 : MOJAVE. XIII. New 15GHz observations on 1994-2013 (Lister+, 2016)
http://www.astro.caltech.edu/ovroblazars : OVRO 40m Telescope Home Page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name OVRO name (G1)
24 A1 --- Class [FBG-] Class (G2)
26- 30 F5.3 --- z Redshift (1)
32- 36 F5.2 --- betaappmax ?=- Maximum apparent velocity
38- 42 F5.2 --- e_betaappmax ?=- rms uncertainty on betaappmax
44- 48 F5.2 K Tvar Variability brightness temperature, Tvar
51- 54 F4.2 K e_Tvar Error on Tvar (lower value)
56- 59 F4.2 K E_Tvar Error on Tvar (upper value)
61- 65 F5.2 --- deltavar Variability Doppler factor, δvar
68- 72 F5.2 --- e_deltavar Error on deltavar (lower value)
74- 78 F5.2 --- E_deltavar Error on deltavar (upper value)
80- 85 F6.2 --- Gammavar ?=- Lorentz factor, Γvar
87- 91 F5.2 --- b_Gammavar Minimum Lorentz factor, Γvar (2)
93 A1 --- lBGammavar [>] Limit flag on Gammavarmax
94- 99 F6.2 --- B_Gammavar Maximum Lorentz factor, Γvar (2)
101-105 F5.2 deg thetavar ?=- Viewing angle, θvar
107-110 F4.2 deg b_thetavar Minimum viewing angle, θvar (2)
112-116 F5.2 deg B_thetavar Maximum viewing angle, θvar (2)
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Note (1): Redshifts are taken from Richards et al. (2014MNRAS.438.3058R 2014MNRAS.438.3058R),
SIMBAD (Wenger et al., 2000A&AS..143....9W 2000A&AS..143....9W,
NASA/IPAC Extragalactic Database (NEDa), and the MOJAVE database
(Lister et al., 2018ApJS..234...12L 2018ApJS..234...12L).
Note (2): Possible minimum and maximum values of each source given
for a given Deltavar by marginalizing over the betaMax distribution.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name OVRO name (G1)
24 A1 --- Class [BG-] Class (G2)
26- 29 F4.2 K Tvar Variability brightness temperature
(no cosmological correction), Tvar (3)
31- 34 F4.2 K b_Tvar Minimum Tvar (4)
36- 40 F5.2 K B_Tvar Maximum Tvar (4)
42- 45 F4.2 --- b_deltavar Minimum variability Doppler factor,
δvar
47- 52 F6.2 --- B_deltavar Maximum variability Doppler factor,
δvar
54- 58 F5.2 --- b_Gammavar Minimum Lorentz factor, Γvar
60 A1 --- lBGammavar [>] Limit flag on Gammavarmax
61- 63 I3 --- B_Gammavar [100] Maximum Lorentz factor, Γvar
65- 67 F3.1 deg b_thetavar [0.0] Minimum viewing angle, θvar
69- 73 F5.2 deg B_thetavar Maximum viewing angle, θvar
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Note (3): Tvar without the cosmological correction (d2_L/(1+z)4, Eq. 1).
Note (4): Possible minimum and maximum values of each source given the minimum
and maximum redshift values in the sample [0.00014,5.47].
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Global notes:
Note (G1): The OVRO name is listed as in the OVRO website:
http://www.astro.caltech.edu/ovroblazars/
Note (G2): Class as follows:
F = flat spectrum radio quasar (FSRQ)
B = BL Lac
G = radio galaxy
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Acknowledgements:
Ioannis Liodakis, ilioda(at)stanford.edu
(End) I. Liodakis [KIPAC, Stanford Univ., USA], P. Vannier [CDS] 25-Sep-2018