RXOS ivo://nasa.heasarc/rixos NASA/GSFC HEASARC Mason et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Optical Counterpart The ROSAT International X-Ray/Optical Survey (RIXOS) is a medium-sensitivity survey and optical identification program for X-ray sources which were discovered in ROSAT high Galactic latitude fields (|b| > 28 degrees) and observed with the Position Sensitive Proportional Counter (PSPC) detector. The survey made use of the central 17 arcmin of each ROSAT field. A flux limit of 3 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> (0.5-2.0 keV) was adopted for this survey, and a minimum exposure time of 8000 seconds was required for qualifying ROSAT observations. X-ray sources in the survey are therefore substantially above the detection threshold of each field used, and many contain enough counts to allow the X-ray spectral slope to be estimated. Spectroscopic observations of potential counterparts were obtained of all sources down to the survey limit in 64 fields, totaling a sky area of 15.77 square degrees. Positive optical identifications are made for 94% of the 296 sources thus examined. A further 18 fields (4.44 sq deg), containing 105 sources above the 3 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> survey limit, are completely optically identified to a higher flux of 8 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> (0.5-2.0 keV). Optical spectroscopic data are supplemented by deep CCD imaging of many sources to reveal the morphology of the optical counterparts, and objects too faint to register on Sky Survey plates. The faintest optical counterparts have R ~ 22. This table contains the catalog of the RIXOS sources and their optical identifications. This table was originally ingested by the HEASARC in June 2005 based on CDS table J/MNRAS/311/456/rixos.dat. It was updated in November 2013 shortly after the CDS released an update with the previously inadvertently omitted source RX J111809.9+212554 (RIXOS 123_84) included. This is a service provided by NASA HEASARC . 2000MNRAS.311..456M https://heasarc.gsfc.nasa.gov/W3Browse/all/rixos.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=rixos& GET text/xml 180 99999 true 61.401 -13.21577778 0.0333333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=rixos GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_rixos&Action=More+Options&Action=Parameter+Search&ConeAdd=1 ROSAT 0.0333333333333333 X-ray public rixos ROSAT International X-Ray/Optical Survey Source Catalog name Source Designation, Derived from the J2000 Coordinates of the X-Ray Centroid 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 count_rate X-Ray Count Rate (ct/s) ct/s phot.count;em.X-ray.soft double nullable count_rate_error RMS Uncertainty on X-Ray Count Rate (ct/s) ct/s stat.error;phot.count;em.X-ray.soft double nullable app_mag Magnitude of the Optical Counterpart (or the Brightest Galaxy for Clusters) mag phot.mag;em.opt double nullable redshift Redshift of Extragalactic Counterparts src.redshift float nullable lii Galactic Longitude degree pos.galactic.lon double nullable emission_fwhm FWHM of the Emission Line (km/s) km/s int nullable emission_lines Emission Lines Observed in AGN and ELG IDs char nullable xray_spect_index_error RMS Uncertainty on X-Ray Spectral Index float nullable ml_counts Total X-Ray Counts Based on Maximum Likelihood Fits ct short nullable app_mag_type Flag Indicates Type of Magnitude char nullable error_radius X-Ray 90% Confidence Positional Radius (arcsec) arcsec stat.error;pos short nullable opt_id Optical Identification Number short nullable flux X-Ray Flux (0.5-2.0 keV) from Measured Count Rate and Spectral Slope of alpha=-1 erg/s/cm^2 phot.flux;em.X-ray.soft double nullable flux_unabs X-Ray Flux from Best Fit and After Correcting for Galactic Absorption erg/s/cm^2 double nullable note_flag Flag Indicates Notes [NIC] char nullable id_flag Flag Indicates Uncertainty on Classification char nullable alt_name RIXOS Source Designation meta.id char nullable redshift_flag Flag Indicates Uncertainty on Redshift char nullable class Browse Object Classification src.class short nullable bii Galactic Latitude degree pos.galactic.lat double nullable xray_spect_index X-Ray Spectral Index float nullable broad_class Broad Category of Optical Classification char nullable opt_spect_index Slope of the Optical Continuum float nullable emission_fwhm_flag RMS Uncertainty on FWHM char nullable source_type Optical Classification Subtype src.class char 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