ROXA - ROXA (Radio-Optical-X-ray at ASDC) Blazars Catalog
The selection method consisted of three steps: 1) a first cross-correlation between radio and X-ray surveys (the NRAO VLA Sky Survey, ATCAPMN (ATCA catalogue of compact PMN sources) and ROSAT All Sky Survey; 2) for each radio/X-ray match, optical magnitudes were retrieved from the Guide Star Catalog; 3) for all radio/optical/X-ray matches the authors calculated the X-ray to optical (alpha_ox) and radio to optical (alpha_ro) spectral slopes and took only sources with alpha_ox and alpha_ro values within the blazar area. For each object, redshift, B and G magnitudes, radio fluxes at 1.4 GHz and at 5 GHz, X-ray flux, F_X/F_r ratio, X-ray luminosity, radio luminosity, Ca H&K break and classification are given.
ROXA: a new multi-frequency large sample of blazars selected with SDSS and 2dF optical spectroscopy. Turriziani S., Cavazzuti E., Giommi P. <Astron. Astrophys. 472, 699 (2007)> =2007A&A...472..699T (SIMBAD/NED BibCode)
The ROXA source designation, using the 'ROXASDC' prefix recommended by the CDS Dictionary of Nomenclature of Celestial Objects (replacing the 'ROXA' prefix used in the reference paper because the latter prefix has been previously used by an earlier CDS Catalog), and a numerical string based on the J2000.0 position ('JHHMMSS.s+DDMMSS.s').
The Right Ascension of the source in the selected equinox. This was given (implicitly through the position-based string part of the source name) in J2000.0 coordinates to a precision of 0.1 seconds of time in the original table.
The Declination of the source in the selected equinox. This was given (implicitly through the position-based string part of the source name) in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table.
The Galactic Longitude of the source.
The Galactic Latitude of the source.
The redshift of the source.
The B_j magnitude of the source (from the 2dF GRS and QSO Surveys).
The g' (g-prime) magnitude of the source (from the SDSS Survey).
The radio flux density of the source at 1.4 GHz (from the NVSS), in mJy.
The radio flux density of the source at 5 GHz (from the North6cm, GB6 and/or PMN Catalogs), in mJy.
The ROSAT All-Sky Survey (RASS) X-fay flux of the source, in erg/s/cm2.
The ratio of the X-ray flux to the 5-GHz radio flux of the source, in erg/s/cm2/Jy. For objects for which no 5-GHz flux density value was available, an estimated value was caculated using F(5 GHz) = F(1.4 GHz) x (20/6)^-alpha_rm, where alpha_rm = 0.25, the assumed average value for flat-spectrum sources.
The X-ray luminosity of the source, in erg/s.
The radio luminosity of the source, in erg/s/Hz.
The Calcium II H and K break contrast value in the optical spectrum of the source.
The source classification, using the following abbreviations:
BLRG = broad line radio galaxies FSRQ = flat spectrum radio quasars HFSRQ = X-ray strong flat-spectrum radio quasars NELG = narrow emission line galaxy QSO RL = radio loud flat-spectrum radio quasar QSO RQ = radio quiet steep-spectrum radio quasar SSRQ = radio loud steep-spectrum radio quasar R.G. FR II = Radio galaxy of FR II type R.G./BL Lac = Radio Galaxy/BL transition object R.G./FSRQ = Radio galaxy/Flat spectrum radio quasars BL Lac/FSRQ = flat spectrum radio quasars/BL transition object
This flag parameter indicates the following notes about the new objects in this catalog:
c = new classification for those objects differently classified in the literature o = new object (never identified before this work) z = objects with newly estimated redshifts
The HEASARC Browse object classification, based on the value of the source_type parameter.