J/ApJ/718/587 The Fermi-AT20G catalog (Mahony+, 2010)
High-frequency radio properties of sources in the Fermi-LAT 1 year point source
catalog.
Mahony E.K., Sadler E.M., Murphy T., Ekers R.D., Edwards P.G., Massardi M.
<Astrophys. J., 718, 587-595 (2010)>
=2010ApJ...718..587M 2010ApJ...718..587M
ADC_Keywords: Active gal. nuclei ; Cross identifications ; Radio continuum ;
Gamma rays
Keywords: galaxies: active - gamma rays: galaxies - radio continuum: galaxies
Abstract:
The high-frequency radio sky, like the gamma-ray sky surveyed by the
Fermi satellite, is dominated by flat spectrum radio quasars and BL
Lac objects at bright flux levels. To investigate the relationship
between radio and gamma-ray emission in extragalactic sources, we have
cross-matched the Australia Telescope 20 GHz survey catalog (AT20G)
with the Fermi-LAT 1 year Point Source Catalog (1FGL). The 6.0sr of
sky covered by both catalogs (DEC<0°,|b|>1.5°) contains 5890
AT20G radio sources and 604 1FGL gamma-ray sources. The AT20G source
positions are accurate to within ∼1 arcsec and, after excluding known
Galactic sources, 43% of Fermi 1FGL sources have an AT20G source
within the 95% Fermi confidence ellipse. Monte Carlo tests imply that
at least 95% of these matches are genuine associations. Only five
gamma-ray sources (1% of the Fermi catalog) have more than one AT20G
counterpart in the Fermi error box. The AT20G matches also generally
support the active galactic nucleus (AGN) associations in the First
LAT AGN Catalog. We find a trend of increasing gamma-ray flux density
with 20GHz radio flux density. The Fermi detection rate of AT20G
sources is close to 100% for the brightest 20GHz sources, decreasing
to 20% at 1Jy, and to roughly 1% at 100mJy. Eight of the matched AT20G
sources have no association listed in 1FGL and are presented here as
potential gamma-ray AGNs for the first time. We also identify an
alternative AGN counterpart to one 1FGL source. The percentage of
Fermi sources with AT20G detections decreases toward the Galactic
plane, suggesting that the 1FGL catalog contains at least 50 Galactic
gamma-ray sources in the southern hemisphere that are yet to be
identified.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 267 233 The Fermi-AT20G catalog
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See also:
VIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/A+A/535/A69 : AGN Fermi/LAT γ-ray and 37GHz fluxes (Nieppola+, 2011)
J/ApJS/194/29 : Observations of blazars at 15GHz (Richards+, 2011)
J/MNRAS/402/2403 : Australia Telescope 20GHz Survey Catalog, AT20G (Murphy+,
2010)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJ/709/1407 : SED of the Fermi blazars (Li+, 2010)
J/ApJ/706/L7 : The Fermi LAT sky as seen by INTEGRAL/IBIS (Ubertini+, 2009)
J/ApJS/183/46 : Fermi/LAT bright gamma-ray source list (0FGL) (Abdo+, 2009)
J/MNRAS/384/775 : Bright Source Sample of AT20G Survey (Massardi+, 2008)
J/ApJS/175/97 : CGRaBS: survey of γ-ray blazar candidates (Healey+,
2008)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [1FGL]
6- 17 A12 --- 1FGL Fermi-LAT name (JHHMM.m+DDMM)
19- 23 F5.1 deg RAdeg Fermi Right Ascension in decimal degrees
(J2000)
25- 29 F5.1 deg DEdeg Fermi Declination in decimal degrees (J2000)
31- 35 F5.3 deg amaj The 95% confidence semi-major axis
37- 41 F5.3 deg amin The 95% confidence semi-minor axis
43- 47 F5.1 deg PA [-90/90] The 95% confidence position angle
49- 54 F6.1 MeV Epiv Pivot energy (1)
56- 63 E8.2 cm-2/MeV/s Flux Differential Gamma-ray flux density at PEng
65- 72 E8.2 cm-2/MeV/s e_Flux Uncertainty in Flux
74- 80 F7.2 --- Var Gamma-ray variability index (2)
82- 86 A5 --- --- [0FGL_]
87- 98 A12 --- 0FGL Fermi Bright Source ID (JHHMM.m+DDMM)
100-116 A17 --- Assoc Fermi association in 1FGL
118-120 A3 --- Class Classification in 1FGL (3)
122-126 A5 --- --- [AT20G]
127-140 A14 --- AT20G AT20G name (JHHMMSS+DDMMSS)
142-143 I2 h RAAh AT20G Hour of Right Ascension (J2000)
145-146 I2 min RAAm AT20G Minute of Right Ascension (J2000)
148-152 F5.2 s RAAs AT20G Second of Right Ascension (J2000)
154 A1 --- DEA- Sign of the AT20G Declination (J2000)
155-156 I2 deg DEAd AT20G Degree of Declination (J2000)
158-159 I2 arcmin DEAm AT20G Arcminute of Declination (J2000)
161-164 F4.1 arcsec DEAs AT20G Arcmsecond of Declination (J2000)
166-170 F5.1 deg GLON AT20G Galactic longitude
172-176 F5.1 deg GLAT AT20G Galactic latitude
178-182 F5.3 deg Off Offset between Fermi and AT20G positions
184-188 I5 mJy S20 Flux density at 20GHz
190-193 I4 mJy S8.4 ? Flux density at 8.4GHz
195-198 I4 mJy S4.8 ? Flux density at 4.8GHz
200-204 F5.2 --- alpha ? Spectral index between 4.8 and 20GHz
206 A1 --- Q [p/g] AT20G flux quality flag (4)
208-212 I5 mJy S1 ? Flux density at 1GHz (5)
214-215 I2 h RAOh ? Optical Hour of Right Ascension (J2000)
217-218 I2 min RAOm ? Optical Minute of Right Ascension (J2000)
220-224 F5.2 s RAOs ? Optical Second of Right Ascension (J2000)
226 A1 --- DEO- Sign of the Optical Declination (J2000)
227-228 I2 deg DEOd ? Optical Degree of Declination (J2000)
230-231 I2 arcmin DEOm ? Optical Arcminute of Declination (J2000)
233-236 F4.1 arcsec DEOs ? Optical Arcmsecond of Declination (J2000)
238-241 F4.1 mag Bmag ? SuperCOSMOS BJ band magnitude
243-247 F5.3 --- z ? Redshift
249-267 A19 --- r_z Reference for z
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Note (1): This is the energy at which the error on the differential flux
is minimal.
Note (2): Values greater than 23.21 have <1% probability of being a steady
source (Abdo et al. 2010, Cat. J/ApJS/188/405).
Note (3): Classification as follows:
BZQ,bzq = flat spectrum radio quasar
agn = non-blazar active galaxies
agu = active galaxies of unknown type
bzb = BL Lac objects
sbg = starburst galaxies
Note (4): Quality flag as follows:
p = poor flux measurement for a variety of reasons explained in
Murphy et al. (2010, Cat. J/MNRAS/402/2403).
g = good flux measurement.
Note (5): from either the NVSS (Cat. VIII/65) or Sydney University Molonglo Sky
Survey (SUMSS, Cat. VIII/81) catalogs.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-Jun-2012