RASSAEQSO - ROSAT All-Sky Survey/ASIAGO-ESO QSO Survey Catalog
The Asiago-ESO/RASS QSO survey. I. The catalog and the local QSO luminosity function. Grazian A., Cristiani S., D'Odorico V., Omizzolo A., Pizzella A. <Astron. J. 119, 2540 (2000)> =2000AJ....119.2540G
(1) In the northern hemisphere, objects with 11.0 < V_GSC <= 14.5 in the GSC catalog.
(2) In the northern hemisphere, objects from the USNO catalog with 13.5 < R_USNO <= 15.4.
(3) In the southern hemisphere, the authors derived B_J magnitudes from the Digitized Sky Survey (DSS). These objects are not included in this table.
The authors cross-correlated the RASS catalog with the photometric databases described above for sources at Galactic latitudes |b| >= 30 deg, and with an RASS-BSC exposure time >= 300 s. Sources classified as extended in the RASS have been disregarded, while no selection based on optical morphology was applied. The looked for optical objects in the ranges 11.0 < V_GSC <= 14.5 and 13.5 < R_USNO <= 15.4 around the RASS sources, adopting a matching radius 3 times the rms positional uncertainty of each entry in the RASS catalog (typically 3 x 12"). In this way, very few (of the order of 0.1%) true identifications in the desired optical range were missed. The resulting catalog covers 8164 deg2 in the north and 5855 deg2 in the south. The list of the quasar candidates and the results of the spectroscopy are listed in this table. According to the authors, it should be noted that this table cannot be considered a list of optical identifications of X-ray sources. The cross-correlation procedure aims at finding optical objects in a desired magnitude range around X-ray sources. In some cases an entry may exist even if the true identification of the X-ray source is another (typically fainter) optical object. For example, even if the optical counterpart of the RASS source J013624.3+205712 is known to be the QSO 3C47.0, with V ~ 18.1 and z = 0.425, in this table the authors list an object with R_USNO = 14.7 that happens to fulfill the criteria of the cross-correlation.
The RASS X-ray source designation.
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 seconds of time in the original table.
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original table.
The Galactic Longitude of the X-ray source.
The Galactic Latitude of the X-ray source.
The USNO R-band magnitude of the optical counterpart to the RASS source. This is available only for sources in the USNO sample.
The GSC V-band magnitude of the optical counterpart to the RASS source. This is available only for sources in the GSC sample.
The B_j-band magnitude of the optical counterpart to the RASS source, taken from the Digitized Sky Survey. This is available only for sources in the sample of other spectroscopic identifications.
The redshift of the optical counterpart to the RASS source.
This flag parameter is set to ':' to indicate that there is uncertainty in the identification and/or redshift.
The identification class of the source, where identifications as "BL Lac" or "Gal" have been taken from NED:
AGN: emission-line object, irrespective of the line width BL: BL Lac object Gal: galaxy Star: star
This parameter was added by the HEASARC in order to allow users to easily identify from which of the 3 samples discussed in the reference paper a given source was taken. Sources which were in Table 2 (the USNO sample), Table 3 (the GSC sample), and Table 4 (other spectroscopic identifications) have been given source_sample values of 'USNO', 'GSC', and 'Other', respectively. 20 sources which were present in both the USNO and GSC samples have been given the source_sample value of 'USNO+GSC'.
The HEASARC Browse object classification, based on the value of the broad_type parameter.