J/ApJ/609/564 Blazar counterparts for 3EG sources (Sowards-Emmerd+, 2004)
Blazar counterparts for 3EG sources at -40°<Decl.<0°: pushing south
through the bulge.
Sowards-Emmerd D., Romani R.W., Michelson P.F., Ulvestad J.S.
<Astrophys. J., 609, 564-575 (2004)>
=2004ApJ...609..564S 2004ApJ...609..564S
ADC_Keywords: BL Lac objects ; Active gal. nuclei ; Redshifts ; Radio sources ;
Gamma rays
Keywords: BL Lacertae objects: general - galaxies: active -
gamma rays: observations - radio continuum: galaxies - surveys
Abstract:
Supplementing existing survey data with Very Large Array (VLA)
observations, we have extended γ-ray counterpart identifications
down to decl.=-40° using our "figure-of-merit" approach. We find
blazar counterparts for 70% of EGRET sources above decl.=-40° away
from the Galaxy. Spectroscopic confirmation is in progress, and
spectra for 24 sources are presented here. We find evidence that
increased exposure in the bulge region allowed EGRET to detect
relatively faint blazars; a clear excess of nonblazar objects in this
region, however, argues for an additional (new) source class.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 114 139 3EG Objects
table2.dat 78 102 VLA A-Array 8.4GHz Observations
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See also:
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 Name (3EG designation, Cat. J/ApJS/123/79)
17 A1 --- n_3EG Note on 3EG (1)
25- 39 A15 --- RName Radio name
40- 44 I5 mJy S8.4GHz ? Flux density at 8.4GHz
45 A1 --- f_S8.4GHz [)] Flag on S8.4GHz (2)
47- 51 F5.2 --- Sp-Index ? Spectral Index
52 A1 --- f_Sp-Index [)] Flag on Sp-Index (2)
55- 59 F5.2 --- DelTS ? Statistical test value, ΔTS (3)
62- 66 F5.2 --- FoM ? Figure of Merit (4)
67 A1 --- f_FoM [)] Flag on FoM (2)
71- 75 F5.3 --- z ? Redshift (from optical observations)
78- 80 A3 --- PID PID, remarks on Redshift (5)
86 I1 --- RID ? Radio data origin (6)
94 A1 --- Mattox [±] Mattox et al. (2001,
Cat. J/ApJS/135/155) selected blazars (7)
102 A1 --- EGRET [Aa] Third EGRET catalog (1999,
Cat. J/ApJS/123/79) blazars (8)
110-111 A2 --- Class Classification of the source (9)
112 A1 --- f_Class [)] Flag on Class (2)
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Note (1): The γ-ray source classification is defined as follows:
N = nonblazar,
b = plausible blazar ID,
B = high-confidence blazar ID,
G = likely Galactic.
Note (2): A ")" indicates that the preceding entry is a predicted value
extrapolating from 1.4/4.8 to 8.4GHz.
Note (3): The TS (test statistic) is the maximum likelihood estimator
used in the EGRET source catalog to quantify the probability that an
EGRET point source is at a given location ; contours of ΔTS from
the maximum define the source uncertainty region:
ΔTS = TSmax-TS(α,δ)
where (α,δ) is the counterpart candidate position.
Note (4): The fractional excesses for each of the counterpart candidate's
properties are combined with the estimate of the positional
probability to compute a total "figure of merit" (FoM) for the source
as a radio/X-ray counterpart:
FoM=n8.4GHz*nα*nX-ray*L(α,δ)
Note (5): New associations and/or redshifts:
* indicates new spectral identification
d indicates archival classification
Note (6): Radio data origin is defined as follows:
0 = not observed,
1 = this VLA campaign,
2 = VLA calibrator survey,
3 = both (1+2).
Note (7): Mattox et al. (2001, Cat. J/ApJS/135/155) selected blazars:
+ = high probability,
- = plausible.
Note (8): Third EGRET catalog (1999, Cat.J/ApJS/123/79) blazars:
A = high confidence,
a = lower confidence.
Note (9): The classification of the source is defined as follows:
b = BL Lac object,
f = FSRQ (flat-spectrum radio quasars),
r = NLRG (narrow-line radio galaxies),
p = pulsar/plerion,
G = likely Galactic,
PN = planetary nebula.
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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- 10 A10 --- VLA VLA name (based on J2000 position)
15- 21 F7.2 mJy S8.4GHz ? VLA Flux at 8.4GHz
24- 29 F6.2 mJy e_S8.4GHz ? Error on S8.4GHz
33- 34 I2 h RAh ? Hour of right ascension (J2000.0)
36- 37 I2 min RAm ? Minute of right ascension (J2000.0)
39- 44 F6.3 s RAs ? Second of right ascension (J2000.0)
49 A1 --- DE- Sign of the declination (J2000.0)
50- 51 I2 deg DEd ? Degree of declination (J2000.0)
53- 54 I2 arcmin DEm ? Arcminute of declination (J2000.0)
56- 60 F5.2 arcsec DEs ? Arcsecond of declination (J2000.0)
65- 84 A20 --- Morph Source morphology (1)
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Note (1): The source morphology is defined as follows:
Jet = distinct jet
Jet? = possible jet
PN = planetary nebula
A few known nonblazar sources are also indicated.
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History:
From electronic version of the journal
References:
Sowards-Emmerd et al., 2003ApJ...590..109S 2003ApJ...590..109S
(End) Marianne Brouty [CDS] 15-Mar-2005