NGC2808CXO ivo://nasa.heasarc/ngc2808cxo NASA/GSFC HEASARC Servillat et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the sources detected in a Chandra X-ray observation of the Galactic globular cluster NGC 2808, as well as the corresponding XMM-Newton data for those sources which have XMM-Newton X-ray counterparts. Using new Chandra X-ray observations and existing XMM-Newton X-ray and Hubble Space Telescope far-ultraviolet observations, the authors aim to detect and identify the faint X-ray sources belonging to NGC 2808 in order to understand their role in the evolution of globular clusters. The authors classify the X-ray sources associated with the cluster by analysing their colors and variability. Previous observations with XMM-Newton and far-ultraviolet observations with Hubble are re-investigated to help identify the Chandra sources associated with the cluster. The authors compare their results to population synthesis models and observations of other Galactic globular clusters. NGC 2808 was observed with the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer-Imager (ACIS-I) on 2007 June 19-21 (28 months after the XMM-Newton observation referred to the reference paper) for two distinct exposures of 46 and 11 kiloseconds. The authors detect 113 sources, of which 16 fall inside the half-mass radius of NGC 2808 and are concentrated towards the cluster core. This table was created by the HEASARC in February 2009 based on the electronic version of Table 1 from the paper which was obtained from the CDS (their catalog J/A+A/490/641 file table1.dat). This is a service provided by NASA HEASARC . 2008A&A...490..641S https://heasarc.gsfc.nasa.gov/W3Browse/all/ngc2808cxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=ngc2808cxo& GET text/xml 180 99999 true 137.989125 -65.04798889 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=ngc2808cxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_ngc2808cxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public ngc2808cxo NGC 2808 Chandra X-Ray Point Source Catalog name Source Designation meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable error_radius 1-Sigma Detection Error arcsec stat.error;pos double nullable counts Number of Counts ct phot;em.X-ray short nullable flux Chandra Flux (erg/s/cm^2) erg/s/cm^2 phot.flux;em.X-ray double nullable flux_error RMS Uncertainty in Chandra Flux erg/s/cm^2 stat.error;phot.flux;em.X-ray double nullable xmm_flux XMM-Newton Flux erg/s/cm^2 phot.flux;em.X-ray double nullable xmm_hardness_ratio XMM-Newton Hardness Ratio phot.flux;arith.ratio;em.X-ray double nullable source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable hardness_ratio_error RMS Uncertainty in Chandra Hardness Ratio stat.error;phot.flux;arith.ratio;em.X-ray double nullable bii Galactic Latitude degree pos.galactic.lat double nullable detect_method Flag [wh] Indicates Detection Method (WAVDETECT or by Hand) meta.code char nullable alt_name Alternative Source Designation meta.id char nullable ks_prob_constant KS Probability of Constancy stat.probability double nullable xmm_flux_error RMS Uncertainty in XMM Flux erg/s/cm^2 stat.error;phot.flux;em.X-ray double nullable hardness_ratio Chandra Hardness Ratio phot.flux;arith.ratio;em.X-ray double nullable xmm_hardness_ratio_error RMS Uncertainty in XMM Hardness Ratio stat.error;phot.flux;arith.ratio;em.X-ray double nullable spectral_index Power Law of Photon Index Best Fit spect.index;em.X-ray double nullable lii Galactic Longitude degree pos.galactic.lon double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable