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Description
The XMM-Newton survey of the Small Magellanic Cloud (SMC) yielded complete coverage of the bar and eastern wing in the 0.2-12.0 keV energy band. In addition to the main-field (5.58 deg<sup>2</sup>), available outer fields were included in the catalogue, yielding a total field area of 6.32 deg<sup>2</sup>. This catalog comprises 3,053 unique X-ray point sources and sources with moderate extent that have been reduced from 5,236 individual detections found in 100 observations between April 2000 and April 2010 (the details of these exposures are given in Table B.1 of the reference paper). For 927 sources, there were detections at multiple epochs, with some SMC fields observed up to 36 times. The detected sources have a median position uncertainty of 1.3 arcseconds (1 sigma) and limiting fluxes down to ~1 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> in the 0.2-4.5 keV band, corresponding to X-ray luminosities of ~5 x 10<sup>33</sup> erg/s for sources located in the SMC. Sources have been classified using X-ray hardness ratios, X-ray variability, and their multi-wavelength properties. In their paper, the authors discuss the statistical properties of the detected X-ray sources, like the spatial distribution, X-ray color diagrams, luminosity functions, and time variability. They have identified 49 SMC high-mass X-ray binaries (HMXB), four super-soft X-ray sources (SSS), 34 foreground stars, and 72 active galactic nuclei (AGN) behind the SMC. In addition, they found candidates for SMC HMXBs (45) and faint SSSs (8) as well as AGN (2092) and galaxy clusters (13). Notice that X-ray sources with high extent (>40 arcseconds), e.g. supernova remnants and galaxy clusters, have been previously presented by Haberl et al. (2012, A&A, 545, A128) and are not included in this table. To investigate the spectral behavior of all sources, the authors used hardness ratios HR<sub>i</sub> (i = 1, 2, 3, 4), defined by HR<sub>i</sub> = (R<sub>i+1</sub> - R<sub>i</sub>)/(R<sub>i+1</sub> + R<sub>i</sub>), where R<sub>i</sub> is the count rate in energy band i as defined by: <pre> Band Energy Range 1 0.2-0.5 keV 2 0.5-1.0 keV 3 1.0-2.0 keV 4 2.0-4.5 keV 5 4.5-12. keV </pre> To increase statistics, the authors also calculated average HR_i<sub>s</sub>, combining all available instruments and observations. HR<sub>i</sub> is not given if both rates R<sub>i</sub> and R<sub>i+1</sub> are null or if the 1-sigma uncertainty of Delta(HR<sub>i</sub>) covers the complete HR interval from -1 to +1. To convert an individual count rate R<sub>i</sub> of an energy band i into a setup-independent, observed flux F<sub>i</sub>, the authors calculated energy conversion factors (ECFs) f<sub>i</sub> = R<sub>i</sub>/F<sub>i</sub> , as described in Sect. A.3 of the reference paper. For the calculation, they assumed a universal spectrum for all sources, described by a power-law model with a photon index of 1.7 and a photo-electric foreground absorption by the Galaxy of N<sub>H,Gal</sub> = 6 x 10<sup>20</sup> cm<sup>-2</sup> (average for the SMC main field in the H I map of Dickey & Lockman 1990, ARAA, 28, 215). In addition to the fluxes for each detection, the authors calculated flux upper limits F<sub>UL</sub> for each observation and source, if the source was observed but not detected in an individual observation. As for the initial source detection, they used the emldetect task to fit sources, but kept the source positions fixed at the master positions and accepted all detection likelihoods in order to get an upper limit for the flux. This table was created by the HEASARC in October 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/558/A3">CDS Catalog J/A+A/558/A3</a> file smc_src.dat. This is a service provided by NASA HEASARC .
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