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J/A+A/490/641     X-ray sources toward NGC 2808              (Servillat+, 2008)

Combined Chandra, XMM-Newton, and Hubble Space Telescope observations of the Galactic globular cluster NGC 2808. Servillat M., Dieball A., Webb N.A., Knigge C., Cornelisse R., Barret D., Long K.S., Shara M.M., Zurek D.R. <Astron. Astrophys., 490, 641-654 (2008)> =2008A&A...490..641S
ADC_Keywords: Clusters, globular ; X-ray sources ; Ultraviolet Keywords: globular clusters: individual: NGC 2808 - X-rays: general - binaries: close - novae, cataclysmic variables Abstract: Using new Chandra X-ray observations and existing XMM-Newton X-ray and Hubble far ultraviolet observations, we aim to detect and identify the faint X-ray sources belonging to the Galactic globular cluster NGC 2808 in order to understand their role in the evolution of globular clusters. We present a Chandra X-ray observation of the Galactic globular cluster NGC 2808. We classify the X-ray sources associated with the cluster by analysing their colours and variability. Previous observations with XMM-Newton and far ultraviolet observations with the Hubble Space Telescope are re-investigated to help identify the Chandra sources associated with the cluster. We compare our results to population synthesis models and observations of other Galactic globular clusters. We detect 113 sources, of which 16 fall inside the half-mass radius of NGC 2808 and are concentrated towards the cluster core. Description: NGC 2808 was observed with the Chandra X-ray Observatory and the Chandra Advanced CCD Imaging Spectrometer-Imager (ACIS-I) at its focus on 2007 June 19-21 (28 months after the XMM-Newton observation) for two distinct exposures of 46 and 11 kiloseconds (ks). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 106 113 Detected Chandra sources in the direction of NGC 2808
See also: B/chandra : The Chandra Archive Log (CXC, 1999-) B/xmm : XMM-Newton Observation Log (XMM-Newton SOC, 2007) J/A+AS/84/59 : Photometry of NGC 2808 (Ferraro+, 1990) J/ApJ/562/368 : UV photometry in NGC 2808 (Brown+, 2001) J/A+A/413/343 : RGB stars in NGC 2808 (Cacciari+, 2004) J/ApJ/625/156 : FUV-NUV observations of NGC 2808 (Dieball+, 2005) J/A+A/480/397 : XMM observations of NGC 2808 and NGC 4372 (Servillat+, 2008) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [SDW2008] Sequential number 5 A1 --- Det [wh] Detection method (WAVDETECT or by hand) 7- 8 A2 --- XMM XMM-Newton ID (1) 10- 11 I2 h RAh Right ascension (J2000) 13- 14 I2 min RAm Right ascension (J2000) 16- 20 F5.2 s RAs Right ascension (J2000) 22 A1 --- DE- Declination sign (J2000) 23- 24 I2 deg DEd Declination (J2000) 26- 27 I2 arcmin DEm Declination (J2000) 29- 33 F5.2 arcsec DEs Declination (J2000) 35- 38 F4.2 arcsec Error 1sigma detection positional error 40- 42 I3 ct Cts Number of X-ray counts 44- 48 F5.2 10-17W/m2 FluxC Chandra flux (10-14erg/cm2/s) 50- 53 F4.2 10-17W/m2 e_FluxC rms uncertainty on Chandra flux 55- 59 F5.2 10-17W/m2 FluxX ?=- XMM flux (10-14erg/cm2/s) 61- 64 F4.2 10-17W/m2 e_FluxX ? rms uncertainty on XMM flux 66- 70 F5.2 --- HRC Chandra hardness ratio (2) 72- 75 F4.2 --- e_HRC rms uncertainty on Chandra hardness ratio 77- 81 F5.2 --- HRX ?=- XMM hardness ratio (2) 83- 86 F4.2 --- e_HRX ? rms uncertainty on XMM hardness ratio 88- 91 F4.2 10+22cm-2 NH [0.12] Absorption column density best fit 93- 97 F5.2 --- PH Power law of photon index best fit 99-106 E8.3 --- KS Kolmogorov-Smirnov probability of constancy
Note (1): From Servillat et al., 2008, Cat. J/A+A/480/397, [SWB2008] NGC 2808 NN or [SWB2008] NGC 2808 CN in Simbad, Note (2): HR=(H-S)/(H+S), where S is the count rate in the 0.5-2keV band and H is the count rate in the 2-8keV band.
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 23-Dec-2008
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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