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J/A+A/539/A74       NGC1893 Chandra X-ray catalog            (Caramazza+, 2012)

Star formation in the outer Galaxy: coronal properties of NGC 1893. Caramazza M., Micela G., Prisinzano L., Sciortino S., Damiani F., Favata F., Stauffer J.R., Vallenari A., Wolk S.J. <Astron. Astrophys. 539, A74 (2012)> =2012A&A...539A..74C
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; X-ray sources Keywords: stars: pre-main sequence - stars: luminosity function, mass function - X-rays: stars - stars: coronae - stars: flare - open clusters and associations: individual : NGC 1893 Abstract: The outer Galaxy, where the environmental conditions are different from the solar neighbourhood is a laboratory in which it is possible to investigate the dependence of star formation process on the environmental parameters. We investigate the X-ray properties of NGC 1893, a young cluster (∼1-2Myr) in the outer part of the Galaxy (galactic radius ≥11kpc) where we expect differences in the disk evolution and in the mass distribution of the stars, to explore the X-ray emission of its members and compare it with that of young stars in star forming regions near to the Sun. Description: We analyze 5 deep Chandra ACIS-I observations with a total exposure time of 450ks. Source events of the 1021 X-ray sources have been extracted with the IDL-based routine ACIS-Extract. Using spectral fitting and quantile analysis of X-ray spectra, we derive X-ray luminosities and compare the respective properties of Class II and Class III members. We also evaluate the variability of sources using the Kolmogorov-Smirnov test and we identify flares in the lightcurves. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file catalog.dat 122 1021 NGC1893 Chandra X-ray catalog: basic source properties uplimit.dat 34 158 Upper limit to the X-ray luminosities for NGC1893 X-ray undetected members
See also: J/A+A/527/A77 : NGC 1893 optical and NIR photometry (Prisinzano+, 2011) Byte-by-byte Description of file: catalog.dat
Bytes Format Units Label Explanations
1- 4 I4 --- Seq Identification number 6- 23 A18 --- Name IAU Designation ( 25- 33 F9.6 deg RAdeg X-ray Right ascension (J2000) 36- 45 F10.6 deg DEdeg X-ray Declination (J2000) 49- 51 F3.1 arcsec e_pos Standard deviation of position 54- 57 F4.1 arcmin OffAxis Off-axis angle 60- 65 F6.1 ct CTn Net counts extracted in the total energy band 68- 71 F4.1 ct e_CTn Average of the upper and lower 1 sigma errors 75- 79 F5.1 ct CTbg Background counts expected in the source extraction region (total band) 82- 85 F4.2 --- PSFf [0/1] Fraction of the PSF (at 1.497keV) enclosed within the extraction region 89- 92 F4.1 --- Signi Photometric significance computed as net counts divided by the upper error on net counts 95-100 F6.4 --- PKS [0/1]? Kolmogorov-Smirnov probability that the lightcurves of the sources are constant 103-107 F5.1 ks t.exp Effective exposure time 110-112 F3.1 keV Emed ? Background-corrected median photon energy (total band) 115-119 F5.2 [10-7W] logLX ? Absorption-corrected X-ray luminosities 122 A1 --- r_logLX ? X-ray Luminosity origin (1)
Note (1): Origin of the X-ray luminosity as follows: a = from fit to a one temperature model spectrum b = from analysis of quantiles c = from a conversion factor derived from the analysis of the quantiles
Byte-by-byte Description of file: uplimit.dat
Bytes Format Units Label Explanations
1- 3 I3 --- ID Prisinzano et al. (2011, Cat. J/A+A/527/A77) identification number 8- 16 F9.6 deg RAdeg Right ascension (J2000) 19- 28 F10.6 deg DEdeg Declination (J2000) 30- 34 F5.2 [10-7W] logTX Estimated upper limit to the absorption-corrected X-ray luminosities
Acknowledgements: Marilena Caramazza, mcarama(at)
(End) Marilena Caramazza [INAF-OAPA, Italy], Patricia Vannier [CDS] 15-Dec-2011
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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