CDROM/APJS/V107/P227 Supplement to Second EGRET Catalog (Thompson+ 1996) ================================================================================ Supplement to the Second EGRET Catalog of High-Energy Gamma-Ray Sources D. J. Thompson, D. L. Bertsch, B. L. Dingus, J. A. Esposito, A. Etienne, C. E. Fichtel, D. P. Friedlander, R. C. Hartman, S. D. Hunter, D. J. Kendig, J. R. Mattox, L. M. McDonald, R. Mukherjee, P. V. Ramanamurthy, P. Sreekumar, C. Von Montigny, J. M. Fierro, B. B. Jones, Y. C. Lin, P. F. Michelson, P. L. Nolan, W. Tompkins, T. D. Willis, G. Kanbach, H. A. Mayer-Hasselwander, M. Merck, M. Pohl, D. A. Kniffen, and E. J. Schneid <1996, ApJS, 107, 227> =1996ApJS..107..227T ================================================================================ 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. Keywords: catalogs -- galaxies: active -- gamma rays:observations Description: Postscript files for figures 1-10 are included (only figures 1-4 appear in the printed paper). File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table1.dat 59 49 EGRET Viewing Periods: Phase 3 table2.dat 140 203 Supplement to the Second EGRET Source Catalog catsupp.txt 79 363 Author-supplied documentation -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 5 A5 --- VP Viewing period 6- 7 2X --- --- Blank 8-24 A17 --- Start Start time, YYYY MMM DD HH:SS 25-26 2X --- --- Blank 27-43 A17 --- End End time, YYYY MMM DD HH:SS 44-51 F8.2 deg GLon Galactic longitude 52-59 F8.2 deg GLat Galactic latitude -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-14 A14 --- Name *Source name 15-22 F8.2 deg RAdeg []? Right ascension, J2000 23-29 F7.2 deg DEdeg []? Declination, J2000 30-37 F8.2 deg GLon []? Galactic longitude 38-44 F7.2 deg GLat []? Galactic latitude 45-49 I5 arcmin A *[]? Semimajor axis, fitted 95% conf. contour 50-53 I4 arcmin B *[]? Semiminor axis, fitted 95% conf. contour 54-59 I6 deg Phi []? Position angle of major axis, E from N 60 A1 --- e_Box [*] Indicates error box not well represented by an ellipse 61-64 A4 --- Mor *Morphology code 65 1X --- --- Blank 66 A1 --- l_F *[<] Flux limiting character 67-72 F6.1 --- F *Flux (E> 100 MeV) or upper limit 73-78 F6.1 --- dF []? 1-sigma statistical uncertainty in F 79-83 F5.1 --- g *[]? Gamma, the photon number spectral index 84-88 F5.1 --- dg []? 1-sigma statistical uncertainty in g 89 1X --- --- Blank 90 A1 --- l_Counts [<] Counts limiting character 91-95 I5 --- Counts *Number of E>100 MeV photons 96-102 F7.1 --- TS *Significance of E>100MeV detection 103-110 A8 --- VP *Viewing period 111-112 2X --- --- Blank 113 A1 --- ID *Coded source identification 114-115 2X --- --- Blank 116-129 A14 --- Other *Other names 130-131 2X --- --- Blank 132 I1 --- Note *Coded note 133-134 2X --- --- Blank 135 A1 --- Ref *Coded reference 136-140 I5 pJy Fnu *Approximate flux density at 400 MeV -------------------------------------------------------------------------------- Notes for file: table2.dat -------------------------------------------------------------------------------- Name: Name based on the J2000 coordinates for the best position of the source, following the IAU naming convention (PASP 102, 1231). 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. If this field is blank, the data in fields l_F, F, dF, g, dg, l_Counts, Counts, TS, VP, ID, Other, Note, and Ref are continuations of the previous record. A, B: Semimajor and semiminor axes, respectively, of an ellipse fitted to the 95% confidence error contour. 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. F: Flux (E> 100 MeV) in 10^{-8} photons/cm^2 s, or upper limit in the same units for observations in which the source was not detected. g: Gamma, the photon number spectral index F(E) ~ E^{-gamma} in the energy range 100-2000 MeV. Spectra have not been determined for all sources. Counts: Number of E>100 MeV photons represented by the flux or upper limit. The uncertainty in the counts is proportional to DeltaF/F. 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. 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. 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). Comparing the 4.85 GHz flux to the Molonglo 408 MHz flux for this source (Large et al. 1981) 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. 1995). Other: The AGN identification in IAU format, or the source name from the first EGRET catalog (Fichtel et al. 1994). 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 artifiacts 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-variabile hard X-ray source GRS1734-292 (Pavlinsky, Grebenev, and Sunyaev, 1994; Churazov et al. 1992) 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 Ref: Previous EGRET references to the source. a McGlynn, et al. 1996, ApJ, in preparation b Nolan, et al. 1996, ApJ, 459, 100 c Fichtel, et al. 1994 (First EGRET Catalog), ApJS, 94, 551 d Sreekumar et al. 1996a, ApJ, in press Fnu: Approximate flux density at 400 MeV (~ 1 x 10 ^{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. -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 27-Feb-97