J/AN/340/437 Optical variability of blazars (Abrahamyan+, 2019)
Optical variability of blazars.
Abrahamyan H. V., Mickaelian A. M., Paronyan G. M., Mikayelyan G. A.
<Astron. Nachrichten, 340, 437-444 (2019)>
=2019AN....340..437A 2019AN....340..437A (SIMBAD/NED BibCode)
ADC_Keywords: BL Lac objects; QSOs; Photometry; Optical; Redshifts;
Radio sources
Keywords: active galactic nuclei; blazar; quasar
Abstract:
The analysis of blazars' parameters from BZCAT leads to a conclusion
that they do not have the same properties. The preliminary criterion
to include an object in the catalog was the strong radio emission;
however, two type of radio sources were selected: BL Lacertae (BLL)
objects and Flat Spectrum Radio Quasars (FSRQ). As a number of
properties are typical of blazars (strong radio emission, optical
variability, continuum optical spectra, polarization, high luminosity,
etc.), using the optical data, we investigate them to clarify which
property plays the most significant role in their classification as
blazars. We found that 60% of blazars have optical variability. We use
a technique developed based on POSS1 and POSS2 photometry and group
the variability into extreme, strong, medium, and low classes. In the
optical range, 51 blazars have powerful variability (extreme
variables), and 126 are high variables. In addition, 63% of blazars
have detected radiation in X-ray and 28% have detected radiation in
gamma rays. We give the average statistical characteristics of blazars
based on our analysis and calculations.
Description:
Having 3561 blazars from the Roma Multifrequency Catalog of Blazars
(BZCAT) 5th version (Massaro+ 2015, VII/274) that have radio
variability, we try to check how many of these sources are optically
variable. We cross-correlated these radio sources with POSS1-based and
POSS2-based optical catalogs: APM (McMahon+ 2000, I/267), USNO A2.0
(Monet+ 1998, I/252), USNO B1.0 (Monet+ 2003, I/284), and GSC 2.3.2
(Lasker+ 2008, I/305).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table8.dat 159 2121 Variable blazars
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See also:
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
I/267 : The APM-North Catalogue (McMahon+, 2000)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
VII/273 : The Half Million Quasars (HMQ) catalogue (Flesch, 2015)
VII/274 : The Roma BZCAT - 5th edition (Massaro+, 2015)
J/A+A/296/665 : Survey of optically variables QSOs (Veron+, 1995)
J/A+A/353/77 : Var. + polarization of luminous quasars (Teerikorpi+, 2000)
J/ApJ/607/665 : Type Ia supernovae at z>1 discovered by HST (Riess+, 2004)
J/AJ/135/1384 : R-band variability in 5 blazars (Gupta+, 2008)
J/MNRAS/407/681 : PMs of FBS blue stellar objects (Mickaelian+, 2010)
J/MNRAS/415/1061 : Variability of FBS blue stellar objects (Mickaelian+ 2011)
J/A+A/529/A91 : Proper motions of 555 quasars from VLBI (Titov+, 2011)
J/A+A/562/A79 : Variability of 7 blazars in six bands (Sandrinelli+, 2014)
J/MNRAS/439/690 : Optical/γ-ray variability in blazars (Hovatta+, 2014)
J/A+A/624/A145 : Astrometric Catalogue 5, LQAC-5 (Souchay+, 2019)
J/other/A+C/25.176 : NVSS and FIRST variable sources (Abrahamyan+, 2018)
J/other/RAA/19.29 : Compilation of known QSOs for Gaia mission (Liao+, 2019)
Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Source name (5BZQ, 5BZB, 5BZG or 5BZU JHHMM+DDMM)
17- 25 F9.5 deg RAdeg BZCAT v5 right ascension (J2000)
28- 36 F9.5 deg DEdeg BZCAT v5 declination (J2000)
39- 43 F5.3 --- z [0.006/6.9]? Redshift from BZCAT v.5
46- 50 F5.2 mag Rmag [0/24.4]? R-band magnitude from BZCAT v.5
53- 58 F6.2 mag RMag [-28.3/-16]? R-band absolute magnitude
61- 71 F11.8 10+38W Lum [0.0008/66.3]? Luminosity in 1045erg/s
74- 78 F5.2 mag B1best [8.5/22.4]? B1 Best magnitude (POSS1)
81- 84 F4.2 mag e_B1best [0/1.3]? B1 Best magnitude error
87- 91 F5.2 mag R1best [7.4/20.9]? R1 Best magnitude (POSS1)
94- 97 F4.2 mag e_R1best [0/1.1]? R1 Best magnitude error
100-104 F5.2 mag B2best [8.7/22.2]? B2 Best magnitude (POSS2)
107-110 F4.2 mag e_B2best [0/1.5]? B2 Best magnitude error
113-117 F5.2 mag R2best [7.6/23.7]? R2 Best magnitude (POSS2)
120-123 F4.2 mag e_R2best [0/1.3]? R2 Best magnitude error
126-130 F5.2 mag delB [-6.1/5.6]? ΔB value
(=|BPOSS2-BPOSS1|-3σB)
133-137 F5.2 mag delR [-6.3/7]? ΔR value
(=|RPOSS2-RPOSS1|-3σR)
140-145 F6.2 --- Br [0/357]? Br=|BPOSS2-BPOSS1|/σB
148-153 F6.2 --- Rr [0/563]? Rr=|RPOSS2-RPOSS1|/σR
156 I1 --- VardB [0/3]? Variability category based on ΔB (1)
157 I1 --- VardR [0/3]? Variability category based on ΔR (1)
158 I1 --- VarBr [0/3]? Variability category based on Br (1)
159 I1 --- VarRr [0/3]? Variability category based on Rr (1)
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Note (1): Variability category as follows (see Table 5):
0 = no variability
1 = low variability (ΔB & ΔR between 0.10-0.74,
Br & Rr between 1.50-1.99)
2 = medium variability (ΔB & ΔR between 0.75-1.24,
Br & Rr between 2.00-2.99)
3 = high variability (ΔB & ΔR ≥1.25, Br & Rr ≥ 3.00)
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Acknowledgements:
Areg Michaekian [Byurakan Astrophysical Observatory (BAO)],
aregmick {at} yahoo.com
(End) Emmanuelle Perret [CDS] 22-Jul-2019