J/ApJS/135/155 Radio identification of 3EG EGRET sources (Mattox+, 2001)
A quantitative evaluation of potential radio identifications
for 3EG EGRET sources.
Mattox J.R., Hartman R.C., Reimer O.
<Astrophys. J. Suppl. Ser. 135, 155 (2001)>
=2001ApJS..135..155M 2001ApJS..135..155M
ADC_Keywords: Gamma rays ; Radio sources ; Cross identifications
Keywords: galaxies: active - gamma rays: observations - quasars: general
Abstract:
The method of Mattox et al. (1996ApJ...461..396M 1996ApJ...461..396M) for identifying
EGRET sources with 5GHz radio sources has been applied to the 3EG
EGRET catalog of Hartman et al. (1999, Cat. J/ApJS/123/79). Complete
results are tabulated. We tabulate separately 46 EGRET sources with
radio identifications which we expect to have a high probability of
being correct. We suggest that these sources are appropriate for most
studies of the properties of γ-ray blazars as a class. All but
one of these 46 sources were classified by Hartman et al. (1999, Cat.
J/ApJS/123/79) as high-confidence identifications; and the
additional source was classified by Hartman et al. (1999, Cat.
J/ApJS/123/79) as a plausible identification. We also tabulate
separately 37 additional "plausible identifications of EGRET sources
with radio sources." These less secure possibilities include the
remaining 21 "high-confidence identifications" of Hartman et al.
(1999, Cat. J/ApJS/123/79), three of the 27 "lower confidence
potential blazar identifications" of Hartman et al. (1999, Cat.
J/ApJS/123/79), and an additional 15 plausible identifications which
have not been suggested previously. Many of these sources require new
radio and optical observations to establish them as blazars. We
suggest that the 23 "lower-confidence potential blazar
identifications" of Hartman et al. (1999, Cat. J/ApJS/123/79) which
we do not find plausible should not be used in studies of the
properties of the EGRET blazars. For this analysis, we have made
elliptical fits to the 95% confidence contours of the position
uncertainty regions of the 3EG sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 141 366 Complete EGRET Identification Results
table2.dat 91 46 EGRET Identifications with a High Probability of
Being Correct
table3.dat 96 39 Plausible EGRET Identifications
table4.dat 64 271 Elliptical fits to the 95% confidence position
contours of all 3EG EGRET sources
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See also:
VIII/13 : A new catalog of 53522 4.85GHz sources (Becker+ 1991)
J/ApJ/481/95 : Radio identification of EGRET sources (Mattox+ 1997)
J/ApJS/101/259 : The second EGRET catalog (Thompson+ 1995)
J/ApJS/107/227 : Supplement to Second EGRET Catalog (Thompson+ 1996)
J/ApJS/123/79 : Third EGRET catalog (3EG) (Hartman+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- 3EG The J2000 3EG EGRET position name
12 A1 --- f_BName [aA] Flag on BName (1)
14- 34 A21 --- BName 3EG Blazar identification
36 A1 --- n_BName [bde] Note on BName (2)
38- 52 A15 --- RName Position name of potential radio counterpart
54 A1 --- f_RName [acfg] Flag on RName (3)
56- 69 A14 --- OName Other or common name for RName
71- 76 I6 mJy S4.85GHz ? Flux density at 4.85GHz from catalog of
Becker et al., VIII/13
78- 81 F4.1 --- Sp+Index ? Radio spectral index (4)
83- 88 F6.1 arcmin R0 ? Characteristic angle (5)
90- 99 E10.4 --- eta ? Probability radio source is a γ-ray
source (see equ. 6)
101-105 F5.1 arcmin Rad ? Angle between the EGRET position estimate
and the radio position
107-111 F5.1 arcmin R95% ? The 95% confidence contour radius in the
direction of the radio source
113 A1 --- l_Cont Limit flag on Cont
114-119 F6.3 % Cont ? EGRET position confidence contour at the
radio position (6)
121-130 E10.4 --- LR ? Likelihood ratio (7)
132-141 E10.4 --- Prob ? The a posteriori probability that the
identification is correct as determined with
equ. 4
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Note (1):
A = Indicates that H-EG3 designated this as a high-confidence AGN
identification.
a = Indicates that H-EG3 designated this as a
``lower-confidence potential'' AGN identification.
Note (2):
b = The poor resolution of the single dish PMN survey does not
provide for definitive results for radio sources near the LMC.
d = The Cen A region is not resolved in the single dish PMN survey.
Therefore, this study is not useful for judging the claim that EGRET
source J1324-4314 is Cen A.
e = EGRET source J1627-2419 is indicated by H-3EG as a possible artifact
due to improper modeling of diffuse γ-ray emission of the
ρ Oph cloud.
Note (3):
a = B0220+4245 is an extended radio source, making it an unlikely
counterpart.
c = EGRET sources J1308+8744 and J1621+8203 lie outside of a 5 GHz
survey region.
f = Radio source J1631-4015 corresponds to a planetary nebula.
g = Radio source B2226+6122 corresponds to a Galactic H II region.
Note (4): S(ν) ∝ να.
Note (5): Angle between potentially confusing radio sources which are at least
as bright and flat as this radio source (equation 3 of
Mattox et al., 1997, Cat. J/ApJ/481/95).
Note (6): See equation 6 of Mattox et al. 1997, Cat. J/ApJ/481/95.
Ranges from 0% at the EGRET position estimate to 100% far away.
Note (7): Indicating the strength of the indication for the identification
(see equation 5).
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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- 12 A12 --- RName Radio name, as in table1.
17- 24 A8 --- Name Radio source name based on 1950 position
26- 29 F4.1 mag Omag ? Optical magnitude from NED
31- 35 I5 mJy S4.85GHz Flux density at 4.85GHz from catalog of
Becker et al., VIII/13
37- 40 F4.1 --- Sp+Index Radio spectral index (2)
42 A1 --- l_SVLBI Limit flag on a SVLBI
43- 46 I4 mJy SVLBI ? VLBI flux density at 2.29 GHz
48- 50 I3 mJy e_SVLBI ? Uncertainty in SVLBI
52- 58 F7.5 --- Prob The a posteriori probability of a
correct identification (3)
60- 64 F5.2 10-6ct/cm2/s Flux The γ-ray flux (E>100MeV) in
units of 10-6cm-2s-1
66- 69 F4.2 10-6ct/cm2/s e_Flux Uncertainty in Flux
71 A1 --- l_z Limit flag on z
72- 77 F6.4 --- z ? Redshift
79- 90 A12 --- n_Name Further notes on Name
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Note (2): S(ν) ∝ να.
Note (3): See equation 10 of Mattox et al. 1997, Cat. J/ApJ/481/95)
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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- 12 A12 --- RName Radio name, as in table1.
17- 25 A9 --- Name Radio source name, based on 1950 position
27 A1 --- f_Name [gh] Flag on Name (2)
29- 33 F5.2 mag Omag ? Optical magnitude from NED
35- 36 I2 h RAh Right Ascension (J2000)
38- 39 I2 min RAm Right Ascension (J2000)
41- 47 F7.4 s RAs Right Ascension (J2000)
50 A1 --- DE- Sign of the Declination (J2000)
51- 52 I2 deg DEd Declination (J2000)
54- 55 I2 arcmin DEm Declination (J2000)
57- 62 F6.3 arcsec DEs Declination (J2000)
65- 68 I4 mJy S4.85GHz Flux density at 4.85GHz from catalog of
Becker et al., VIII/13
70- 73 F4.1 --- Sp+Index ? Radio spectral index (3)
75- 79 F5.3 --- Prob The a posteriori probability of a correct
identification (eq. 4).
81 A1 --- f_Prob [f] Flag on Prob (4)
83- 94 A12 --- Morph The ``Morphological Type'' from NED
96 A1 --- f_Morph [aA] Flag on Morph (5)
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Note (2):
g = Both 1930-397 and 1933-400 are potential identifications of
3EG J1935-4022.
h = Both 1936-155 and 1938-155 are potential identifications of
3EG J1937-1529.
Note (3): S(ν) ∝ να.
Note (4):
f = The high confidence identification of 1219+285 by H-3EG is based on
the E>1 GeV position of Lamb & Macomb (1997). Using their position
result, we find Prob=0.04 for 1219+285.
Note (5):
A = Indicates that H-EG3 designated this source as a high-confidence
EGRET identification.
a = Indicates that H-EG3 designated this source as a
``lower-confidence potential'' EGRET identification.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- 3EG The 3EG EGRET γ-ray position name
12- 17 F6.2 deg RAdeg Right Ascension expressed in degrees (J2000)
19- 24 F6.2 deg DEdeg Declination expressed in degrees (J2000)
26- 31 F6.2 deg GLON Galactic longitude
33- 38 F6.2 deg GLAT Galactic latitude
40- 44 F5.1 arcmin MajAxis Semi-major axis length
46- 50 F5.1 arcmin MinAxis Semi-minor axis length
52- 54 I3 deg PA Position angle of MajAxis
56- 57 A2 --- f_PA Flag on PA (1)
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Note (1):
a = A poor elliptical fit, a fit to a compromised map, or an anomalous
error region. The elliptical fits should only be used with caution for
these sources.
b = The 68% contour is not centered in the 95% contour, causing an offset
from the position of H-3EG.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 10-Sep-2001