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J/ApJ/561/189            Chandra X-ray sources in M101            (Pence+, 2001)

Chandra X-ray sources in M101. Pence W.D., Snowden S.L., Mukai K., Kuntz K.D. <Astrophys. J. 561, 189 (2001)> =2001ApJ...561..189P
ADC_Keywords: X-ray sources Keywords: galaxies: individual (M101) - galaxies: spiral - X-rays: galaxies Abstract: A deep (98.2ks) Chandra Cycle 1 observation has revealed a wealth of discrete X-ray sources as well as diffuse emission in the nearby face-on spiral galaxy M101. From this rich data set we have created a catalog of the 110 sources from the S3 chip detected with a significance of greater than 3σ. This detection threshold corresponds to a flux of ∼10-16ergs/cm2/s and a luminosity of ∼1036ergs/s for a distance to M101 of 7.2Mpc. The sources display a distinct correlation with the spiral arms of M101 and include a variety of X-ray binaries, supersoft sources, supernova remnants, and other objects of which only ∼27 are likely to be background sources. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 79 110 S3 Chip X-ray Sources in M101 table2.dat 41 27 Cross-Identifications table4.dat 63 29 XSPEC Model Fits to the 29 Brightest Sources
See also: J/ApJ/560/675 : Chandra X-ray point sources in Cen A (Kraft+, 2001) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [PSM2001] Source number 5- 6 I2 h RAh Right Ascension (J2000) 8- 9 I2 min RAm Right Ascension (J2000) 11- 15 F5.2 s RAs Right Ascension (J2000) 16 A1 --- DE- Declination sign (J2000) 17- 18 I2 deg DEd Declination (J2000) 20- 21 I2 arcmin DEm Declination (J2000) 23- 26 F4.1 arcsec DEs Declination (J2000) 28- 30 I3 pix Area Area of source region in units of the 0.49" CHANDRA CCD pixels 32- 35 I4 ct S1 First soft X-ray energy band net counts (1) 37- 40 I4 ct M1 First medium X-ray energy band net counts (1) 42- 44 I3 ct H1 First hard X-ray energy band net counts (1) 46- 49 I4 ct S2 Second soft X-ray energy band net counts (1) 51- 54 I4 ct M2 Second medium X-ray energy band net counts (1) 56- 58 I3 ct H2 Second hard X-ray energy band net counts (1) 60- 65 F6.2 [mW/m2] logFS2 ? Log of the S2 X-ray flux (in erg/cm2/s) 67- 72 F6.2 [mW/m2] logFM2 ? Log of the M2 X-ray flux (in erg/cm2/s) 74- 79 F6.2 [mW/m2] logFH2 ? Log of the H2 X-ray flux (in erg/cm2/s)
Note (1): The energy ranges for the first set of bands (S1, M1, and H1) were selected to produce roughly equal count rates in each band for the typical sample of sources seen in M101. For the second set of bands (S2, M2, and H2) a more standard set of astrophysically relevant energy ranges were used to facilitate the comparison of our results with those from previous X-ray missions. The energy bands are: S1=0.125-0.8keV; M1=0.8-1.3keV; H1=1.3-8.0keV; S2=0.125-0.5keV; M2=0.5-2.0keV; H2=2.0-8.0keV.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [PSM2001] Source number 6- 8 A3 --- [WIP99] ROSAT source identification from Wang et al., 1999ApJ...523..121W, [WIP99] NN in Simbad 10- 14 A5 --- n_[WIP99] Note on the nature of the source 16- 19 A4 --- [MF97] SNR identification from Matonick & Fesen, 1997ApJS..112...49M, [MF97] M101 NN in Simbad 22- 41 A20 --- Other Other identifications
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [PSM2001] Source number 5- 8 F4.2 --- alpha ? Simple absorbed power-law spectrum model parameter (1) 10- 13 F4.2 kT BB ? Absorbed blackbody model parameter (1) 15- 19 F5.2 10+21cm-2 NH Hydrogen column density 21- 24 F4.2 --- Chi2V Reduced chi2 value 26- 31 F6.2 [mW/m2] logFXS2 X-ray flux over the energy range of the S2 (0.12-50.5keV) energy band (2) 33- 38 F6.2 [mW/m2] logFXM2 X-ray flux over the energy range of the M2 (0.5-2.0keV) energy band (2) 40- 45 F6.2 [mW/m2] logFXH2 X-ray flux over the energy range of the H2 (2.0-8.0keV) energy band (2) 47- 51 F5.2 [10-7W] logLXS2 X-ray luminosity in S2 energy band (0.12-50.5keV) (3) 53- 57 F5.2 [10-7W] logLXM2 X-ray luminosity in M2 energy band (0.5-2.0keV) (3) 59- 63 F5.2 [10-7W] logLXH2 X-ray luminosity in H2 energy band (2.0-8.0keV) (3)
Note (1): Most of the sources could be satisfactorily fitted with a simple absorbed power-law spectrum model; however, eight of the softest sources were better fitted by an absorbed blackbody model. Note (2): Apparent X-ray fluxes calculated by integrating the model spectrum over the energy range of the S2, M2 and H2 energy bands. Note (3): Intrinsic X-ray luminosity of the source in each of the three bands, correcting for the model NH absorption and assuming a distance of 7.2Mpc to M101.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 14-Jan-2002
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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