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J/ApJ/615/897   Chandra X-Ray sources in the γ Cyg Field   (Becker+, 2004)

A multiwavelength search for a counterpart of the brightest unidentified gamma-ray source 3EG J2020+4017 (2CG 078+2). Becker W., Weisskopf M.C., Arzoumanian Z., Lorimer D., Camilo F., Elsner R.F., Kanbach G., Reimer O., Swartz D.A., Tennant A.F., O'Dell S.L. <Astrophys. J., 615, 897-907 (2004)> =2004ApJ...615..897B
ADC_Keywords: X-ray sources ; Gamma rays ; Radio sources ; Infrared sources Keywords: ISM: individual (G78.2+2.1) - X-rays: individual (RX J2020.2+4026) Abstract: In search of the counterpart to the brightest unidentified gamma-ray source, 3EG J2020+4017 (2CG 078+2), we report on new X-ray and radio observations of the γ Cygni field with the Chandra X-Ray Observatory and with the Green Bank Telescope (GBT). We also report on reanalysis of archival ROSAT data. Description: Our 30ks Chandra observation (observation ID 3856) was taken on 2003 January 26 using three Advanced CCD Imaging Spectrometer (ACIS) CCDs (S2, S3, and S4) in the faint, timed-exposure mode with a frame time of 3.141 s. A deep search for radio pulsations from 2CG 078+2 was carried out using the Green Bank Telescope (GBT) on 2003 December 27. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 68 38 Chandra X-Ray sources in the γ Cygni field table2.dat 70 34 Candidate counterparts to the X-ray sources in the γ Cygni field
See also: J/ApJS/123/79 : Third EGRET catalog (3EG) (Hartman+, 1999) I/284 : The USNO-B1.0 Catalog (Monet+ 2003) II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999) IX/28 : ROSAT HRI Pointed Observations (1RXH) (ROSAT Team, 2000) IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000) IX/30 : Second ROSAT PSPC Catalog (ROSAT, 2000) IX/32 : ROSAT Bright Survey (Fischer+, 1998-2000) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 A4 --- [BWA2004] Name 7- 15 F9.5 deg RAdeg Right Ascension (J2000) 18- 26 F9.6 deg DEdeg Declination (J2000) 29- 33 F5.2 arcsec r1 Extraction radius 36- 38 I3 ct N Approximate vignetting-corrected number of source counts 41- 44 F4.1 --- S/N Detection signal-to-noise ratio 47- 50 F4.2 arcsec r2 X-ray position uncertainty (1sigma radius) (1) 53- 56 F4.2 arcsec Sep1 ? Radial separation between X-ray position and USNO position of counterpart 59- 62 F4.2 arcsec Sep2 ? Radial separation between X-ray position and 2MASS position of counterpart 65- 67 F3.1 arcsec Sep3 ? Radial separation between X-ray position and ROSAT position of counterpart 68 A1 --- f_Sep3 Flag on Sep3 (2)
Note (1): The positional uncertainty is given by r=1.51"(σ2/N+σ02)1/2, where σ is the size of the circular Gaussian that approximately matches the point-spread function (PSF) at the source location, N is the vignetting-corrected number of source counts, and σ0 represents the systematic error. Note (2): The flag on Sep3 is defined as follows: a = 1RXH J2020.2+4026; the positional uncertainty is 6" b = 1RXH J202040.9+402704; the positional uncertainty is larger than the separation (2"-3") c = 1RXH J202057.8+402829; the positional uncertainty is 1" d = 1RXH J202111.4+402807; the positional uncertainty is 2"-------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 4 A4 --- [BWA2004] Name 7- 16 F10.6 deg RAdeg ? USNO Right Ascension (J2000) 19- 27 F9.6 deg DEdeg ? USNO Declination (J2000) 30- 34 F5.3 ct N(USNO) ? Average number of accidental coincidences expected in the region searched (1) 37- 46 F10.6 deg RA2deg ? 2MASS Right Ascension (J2000) 49- 57 F9.6 deg DE2deg ? 2MASS Declination (J2000) 60- 64 F5.3 ct N(2MASS) ? Average number of accidental coincidences expected in the region searched (1) 67- 70 F4.2 arcsec delta ? Angular separation between the USNO and 2MASS candidate counterpart
Note (1): The probability of getting one or more matches by chance is given by the Poisson probability 1-exp(-Nr99), which for small values is approximately Nr99.
History: From electronic version of the journal
(End) Marianne Brouty [CDS] 26-May-2005
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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