J/ApJS/107/227 Supplement to Second EGRET Catalog (Thompson+ 1996)
Supplement to the Second EGRET Catalog of High-Energy Gamma-Ray Sources
Thompson D.J., Bertsch D.L., Dingus B.L., Esposito J.A., Etienne A.,
Fichtel C.E., Friedlander D.P., Hartman R.C., Hunter S.D.,
Kendig D.J., Mattox J.R., McDonald L.M., Mukherjee R.,
Ramanamurthy P.V., Sreekumar P., Von Montigny C., Fierro J.M.,
Jones B.B., Lin Y.C., Michelson P.F., Nolan P.L., Tompkins W.,
Willis T.D., Kanbach G., Mayer-Hasselwander H.A., Merck M., Pohl M.,
Kniffen D.A., , Schneid E.J.
<Astrophys. J. Suppl. Ser. 107, 227 (1996)>
=1996ApJS..107..227T 1996ApJS..107..227T
ADC_Keywords: Gamma rays
Mission_Name: CGRO
Keywords: catalogs - galaxies: active - gamma rays: observations
Abstract:
This supplement extends the second EGRET catalog of high-energy
gamma-ray sources (see recent paper by Thompson et al.), incorporating
data from 1993 September to 1994 October. The second catalog contained
129 sources, based on data from 1991 April to 1993 September. An
additional 28 sources are found, including three new identifications
of active galactic nuclei.
Description:
Postscript files for figures 1-10 are included (only figures 1-4 appear
in the printed paper).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 53 49 EGRET Viewing Periods: Phase 3
table2 140 203 Supplement to the Second EGRET Source Catalog
catsupp.txt 79 363 Author-supplied documentation
figure1.ps 120 3195 Sky coverage during Phase 3 observations
figure2.ps 120 3441 Total coverage during Phases 1 through 3
figure3.ps 81 711 Locations of the 28 sources of the supplement to
the Second EGRET catalog
figure4.ps 79 1343 Locations of all 157 sources seen in the second
EGRET catalog plus this supplement
figure5.ps 76 1383 Color version of figure4
figure6.ps 76 659 Maps of locations of sources in this catalog
figure7.ps 76 662 Maps of locations of sources in this catalog
figure8.ps 76 671 Maps of locations of sources in this catalog
figure9.ps 76 681 Maps of locations of sources in this catalog
figure10.ps 76 460 Maps of locations of sources in this catalog
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See also:
J/ApJS/94/551 : The first EGRET catalog (Fichtel+ 1994)
J/ApJS/101/259 : The second EGRET catalog (Thompson+ 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- VP Viewing period
8- 15 A8 "DD/MM/YY" Start.Day Start time, Year, Month, Day
17- 18 I2 h Start.h Start time (hours)
20- 21 I2 min Start.m Start time (minutes)
24- 31 A8 "DD/MM/YY" End.Day End time, Year, Month, Day
33- 34 I2 h End.h End time (hours)
36- 37 I2 min End.m End time (minutes)
39- 45 F7.2 deg GLON Galactic longitude
48- 53 F6.2 deg GLAT Galactic latitude
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 14 A14 --- 2EGS *Source name
16- 22 F7.2 deg RAdeg Right ascension, J2000
24- 29 F6.2 deg DEdeg Declination, J2000
31- 37 F7.2 deg GLON Galactic longitude
39- 44 F6.2 deg GLAT Galactic latitude
46- 49 I4 arcmin A *Semimajor axis, fitted 95% conf. contour
51- 53 I3 arcmin B *Semiminor axis, fitted 95% conf. contour
55- 59 I5 deg Phi Position angle of major axis, E from N
60 A1 --- ErrBox [*] Indicates error box not well
represented by an ellipse
61- 64 A4 --- Mor *Morphology code
66 A1 --- l_Flux [<] Flux limiting character
67- 72 F6.1 10-8ct/cm2/s Flux *Flux (E> 100 MeV) or upper limit
74- 78 F5.1 10-8ct/cm2/s e_Flux ? 1-sigma statistical uncertainty in F
80- 83 F4.1 --- gamma *? Gamma, the photon number spectral index
85- 88 F4.1 --- e_gamma ? 1-sigma statistical uncertainty in g
90 A1 --- l_Counts [<] Counts limiting character
91- 95 I5 ct Counts *Number of E>100 MeV photons
97-102 F6.1 ct TS *Significance of E>100MeV detection
103-110 A8 --- VP *Viewing period
113 A1 --- ID *Coded source identification
116-129 A14 --- Other *Other names
132 I1 --- Note *? Coded note
135 A1 --- Ref *Coded reference
137-140 I4 pJy Fnu *? Approximate flux density at 400 MeV
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Note on 2EGS:
Name based on the J2000 coordinates for the best position of the
source, following the IAU naming convention (1990PASP..102.1231D 1990PASP..102.1231D). It
should be emphasized that the measured positions are generally not
as precise as the name might suggest. The 2EGS designation is used
to distinguish these sources from those of the second catalog, which
were designated 2EG.
Note on A, B:
Semimajor and semiminor axes, respectively, of an ellipse fitted
to the 95% confidence error contour.
Note on Mor:
Morphology: E = extended source (applies only to the LMC);
em = possibly extended source or multiple sources (based on source
location maps inconsistent with a single point source or
poor fit to the calibrated point-spread function;
C = source confusion may affect flux, significance, or position.
Sources with no entry in this column are consistent with
the EGRET point-spread function for a single source.
Note on Flux:
Flux (E> 100 MeV) in 10{-8}photons/cm2/s, or upper limit in
the same units for observations in which the source was not detected.
Note on gamma:
Gamma, the photon number spectral index F(E)∼E-γ in the energy
range 100-2000MeV. Spectra have not been determined for all sources.
Note on Counts:
Number of E>100 MeV photons represented by the flux or upper limit.
The uncertainty in the counts is proportional to {DELTA}F/F.
Note on TS:
sqrt{TS} -- Statistical significance of the E>100 MeV detection.
It is approximately equal to the statistical sigma for a single
measurement at a fixed position.
Note on VP:
Viewing period of the observation.
P12 = Phase 1 + 2 summed map 4/91 - 9/93;
P3 = Phase 3 summed map 9/93 - 10/94;
P123 = Phase 1 + 2 + 3 summed map 4/91 - 10/94.
321+ is the sum of viewing periods 321.0 and 321.5, which cover the
same region of the sky.
331+ is the sum of viewing periods 331.0 and 331.5, which cover the
same region of the sky.
Note on ID:
Coded source identification:
A = Active Galactic Nucleus;
a? = possible Active Galactic Nucleus. This applies only to source
2EGS J1800-4005, which is positionally consistent with the bright
radio source PMN J1802-3940 (Gregory et al. 1994, Cat. J/ApJS/90/173).
Comparing the 4.85 GHz flux to the Molonglo 408 MHz flux for this source
(Large et al. 1981, Cat. VIII/16) indicates a flat spectrum. The
bright, flat-spectrum radio source, coupled with the gamma-ray time
variability, suggest that this may be a blazar like others detected
by EGRET (Montigny et al. 1995ApJ...440..525V 1995ApJ...440..525V).
Note on Other:
The AGN identification in IAU format, or the source name from
the first EGRET catalog (Fichtel et al. 1994, Cat. J/ApJS/94/551).
Note on Note:
Positional coincidences with objects of interest which might be the
gamma-ray source, or special information about the detection.
1 Surveys of the CO emission used to trace molecular hydrogen are
incomplete in the Orion and Ophiuchus regions. Weak sources in
these regions may be artifacts of the diffuse gamma-ray model.
2 2EGS J0852-4343 is located in the wings of the bright Vela pulsar
3 2EGS J1736-2904 is positionally consistent with the time-variable
hard X-ray source GRS1734-292 (Pavlinsky, Grebenev, and Sunyaev,
1994ApJ...425..110P 1994ApJ...425..110P; Churazov et al. 1992IAUC.5623....1C 1992IAUC.5623....1C)
4 2EGS J1800-4005 is positionally consistent with radio source PMN J1802-3940.
This source has a flat radio spectrum and may, therefore, be a blazar
similar to other identified EGRET active galactic nuclei
Note on Ref:
Previous EGRET references to the source.
a McGlynn, et al., 1997ApJ...481..625M 1997ApJ...481..625M
b Nolan, et al., 1996ApJ...459..100N 1996ApJ...459..100N
c Fichtel, et al., 1994 (First EGRET Catalog), Cat. J/ApJS/94/551
d Sreekumar et al., 1996ApJ...464..628S 1996ApJ...464..628S
Note on Fnu:
Approximate flux density at 400 MeV (∼1x10{23}Hz) in units of picoJy.
The statistical uncertainty in the flux density is proportional to {DELTA}F/F.
For each source, this entry is given only for the detection with the highest
statistical significance and is rounded to the nearest 5 picoJy to emphasize
the approximate nature of the result. The specific approximations used in
deriving the flux density are discussed in the Appendix.
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Origin: AAS CD-ROM series, Volume 8, 1997 Lee Brotzman [ADS] 27-Feb-97
(End) [CDS] 04-Jul-1997