J/ApJ/707/L56 VLBI and bright Fermi/LAT sources (Kovalev, 2009)
Identification of the early Fermi/LAT gamma-ray bright objects with
extragalactic VLBI sources.
Kovalev Y.Y.
<Astrophys. J., 707, L56-L59 (2009)>
=2009ApJ...707L..56K 2009ApJ...707L..56K
ADC_Keywords: Gamma rays ; Radio continuum ; Cross identifications
Keywords: catalogs - galaxies: active - gamma rays: observations -
radio continuum: galaxies
Abstract:
A list of 205 γ-ray strong objects was reported recently as a
result of a three-month integration with the Large Area Telescope on
board the Fermi Gamma-Ray Space Telescope. We attempted identification
of these objects, cross-correlating the γ-ray positions with
very long baseline interferometry (VLBI) positions of a large all-sky
sample of extragalactic radio sources selected on the basis of their
parsec-scale flux density. The original associations reported by the
Fermi team are confirmed, and six new identifications are suggested. A
Monte Carlo analysis shows that the fraction of chance associations in
our analysis is less than 5%, and confirms that the vast majority of
γ-ray bright extragalactic sources are radio-loud blazars with
strong parsec-scale jets. A correlation between the parsec-scale radio
and γ-ray flux is supported by our analysis of a complete VLBI
flux-density-limited sample of extragalactic jets. The effectiveness
of using a VLBI catalog to find associations between γ-ray
detections and compact extragalactic radio sources, especially near
the Galactic plane, is demonstrated. It is suggested that VLBI
catalogs should be used for future identification of Fermi/LAT
objects.
Description:
The full list of the 205 bright γ-ray sources presented by Abdo
et al. (2009, Cat. J/ApJS/183/46; superseded by Cat. J/ApJS/188/405)
includes both Galactic and extragalactic objects. We have successfully
identified 111 VLBI sources out of the 205 Fermi/LAT sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 73 111 VLBI associations of the Fermi LAT bright sources
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See also:
I/251 : VLBI International Celestial Reference Frame (ICRF) (Ma+, 1997)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJS/183/46 : Fermi/LAT bright gamma-ray source list (0FGL) (Abdo+, 2009)
J/AJ/136/580 : Sixth VLBA calibrator survey: VCS6 (Petrov+, 2008)
J/AJ/133/1236 : Fifth VLBA calibrator survey: VCS5 (Kovalev+, 2007)
J/AJ/131/1872 : Fourth VLBA calibrator survey: VCS4 (Petrov+, 2006)
J/AJ/129/1163 : Third VLBA calibrator survey: VCS3 (Petrov+, 2005)
J/AJ/127/3587 : VLBI ICRF. II (Fey+, 2004)
J/AJ/126/2562 : Second VLBA calibrator survey: VCS2 (Fomalont+, 2003)
J/ApJS/141/13 : VLBA calibrator survey: VCS1 catalog (Beasley+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [0FGL]
6- 17 A12 --- 0FGL Fermi LAT bright source name (JHHMM.m+DDMM)
19- 26 A8 --- VLBI IAU name (HHMM+DDd, B1950) of VLBI association
( or in Simbad)
28- 32 F5.3 deg DP Fermi LAT and VLBI association position difference
34- 38 F5.3 deg R95 Fermi LAT 95% confidence radius
40- 41 I2 h RAh VLBI association Hour of Right ascension (J2000)
43- 44 I2 min RAm VLBI association Minute of Right ascension (J2000)
46- 52 F7.4 s RAs VLBI association Second of Right ascension (J2000)
54 A1 --- DE- VLBI association Sign of the Declination (J2000)
55- 56 I2 deg DEd VLBI association Degree of Declination (J2000)
58- 59 I2 arcmin DEm VLBI association Arcminute of Declination (J2000)
61- 67 F7.4 arcsec DEs VLBI association Arcsecond of Declination (J2000)
69- 73 F5.2 Jy S8 ? Total parsec-scale flux density at 8GHz
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 06-Jan-2012