ROMABZCAT ivo://nasa.heasarc/romabzcat NASA/GSFC HEASARC Massaro et al. 2026-08-14 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the 5th edition of the Roma-BZCAT catalog of blazars which contains coordinates and multi-frequency data of 3561 sources. It presents several relevant changes with respect to the past editions which are briefly described in the reference paper. The Roma-BZCAT catalog contains data on 3561 sources, about 30% more than in the 1st edition, which either confirmed blazars or exhibiting characteristics close to this type of sources. With respect to the previous editions, this new edition has relevant changes in the sources' classification. The authors emphasize that all the sources in the Roma-BZCAT have a detection in the radio band. Moreover, complete spectroscopic information is published and could be accessed by the authors for all of them, with the exception of BL Lac candidates. Consequently, peculiar sources such as the so called "radio quiet BL Lacs", which are reported in some other catalogs, are not included here because of possible contamination by hot stars and other extragalactic objects. In the 5th edition, the authors use a similar denomination for the blazars to that adopted in the previous editions. Each blazar is identified by a code, with 5BZ for all blazars, a fourth letter that specifies the type (B, G, Q or U), followed by the truncated equatorial coordinates (J2000). The authors introduced the edition number before the letters BZ to avoid possible confusion due to the fact that several sources changed their old names because of a newly adopted classification. The 5th edition contains 1151 BZB sources (92 of which are reported as candidates because their optical spectra could not be found in the literature), 1909 BZQ sources, 274 BZG sources, and 227 BZU objects. This database table was originally ingested by the HEASARC in September 2013, based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/495/691">CDS Catalog J/A+A/495/691</a> file bzcat4.dat. It was updated in March 2016, and it is now based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/274">CDS Catalog VII/274</a> file bzcat5.dat. This is a service provided by NASA HEASARC . 2015Ap&SS.357...75M https://heasarc.gsfc.nasa.gov/W3Browse/all/romabzcat.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=romabzcat& GET text/xml 180 99999 true 145.48170833 -86.2505 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=romabzcat GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_romabzcat&Action=More+Options&Action=Parameter+Search&ConeAdd=1 GALAXY CATALOG 0.0166666666666667 Gamma-ray Optical X-ray public romabzcat Roma-BZCAT Multi-Frequency Catalog of Blazars source_number Sequential Identification Number for Each Source in the Catalog meta.id;src short nullable name Source Designation ([MML2015] 5BZx JHHMM+DDMM) 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 redshift Redshift src.redshift double nullable redshift_flag Uncertainty Flag [?] for Redshift meta.code;src.redshift char nullable flux_1p4_ghz Radio Flux Density at 1.4/0.843-GHz mJy phot.flux.density;em.radio.750-1500MHz double nullable rmag R-Band Magnitude mag phot.mag;em.opt.R double nullable xray_flux X-Ray Flux (0.1-2.4keV) erg/cm^2/s phot.flux;em.X-ray.soft double nullable object_type Source Classification 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 flux_143_ghz Flux Density at 143GHz mJy phot.flux.density;em.mm.100-200GHz int nullable gr_photon_flux Fermi Gamma-Ray Flux (1-100GeV) photon/cm^2/s phot.flux;em.gamma.hard double nullable ro_spectral_index Spectral Index Radio-Optical spect.index;em.radio;em.opt double nullable bii Galactic Latitude degree pos.galactic.lat double nullable lii Galactic Longitude degree pos.galactic.lon double nullable