BeppoSAX High-Energy Large Area Survey (HELLAS) Radio Source Catalog

BeppoSAX High-Energy Large Area Survey (HELLAS) Radio Source Catalog SAXHELLASR ivo://nasa.heasarc/saxhellasr NASA/GSFC HEASARC Ciliegi et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains results of a complete radio follow-up obtained with the VLA and ATCA radio telescopes down to a 6-cm flux limit of about 0.3 mJy (3-sigma) of all the 147 X-ray sources detected in the BeppoSAX HELLAS survey (Fiore et al. 2001, MNRAS, 327, 771). The authors found 53 X-ray/radio likely associations, corresponding to about one-third of the X-ray sample. Using the two-point spectral index alpharo = 0.35 they divided all the HELLAS X-ray sources into radio-quiet and radio-loud. They have 26 sources classified as radio-loud objects, corresponding to 18 per cent of the HELLAS sample. In agreement with previous results, the identified radio-loud sources are associated mainly with Type 1 active galactic nuclei (AGNs) with L5-10keV >~ 1044 erg/s, while all the identified Type 2 AGNs and emission-line galaxies are radio-quiet objects with L5-10keV <~ 1044 erg/s. The 20 HELLAS sources with Declinations south of -40o were observed with the ATCA, while the 127 sources with more northerly Declinations were observed with the VLA. For these latter sources a complete covering at 20 cm down to the 5-sigma flux limit of 2.5 mJy is already available with the NRAO/VLA Sky Survey (NVSS) while the FIRST survey (Faint Images of the Radio Sky at Twenty centimeters) is available only for 27 HELLAS sources (5-sigma limit of ~ 1 mJy).In order to obtain information also on the radio spectral properties of the HELLAS sources the authors adopted the following strategy. All the 147 HELLAS sources were observed at 6 cm down to a 1 -sigma flux limit of ~ 0.10 - 0.25 mJy. For the 20 HELLAS sources observed with the ATCA, they took advantage of the fact that the 6 and 3 cm receivers of the ATCA share a common feed-horn and they observed simultaneously also at 3 cm, obtaining a 3-cm flux limit of ~ 0.22 mJy (1-sigma level). Starting from the radio position of the 53 X-ray/radio associations, the authors searched for optical counterparts within 5 arcseconds from the radio position using the optical positions of the 61 HELLAS sources identified by La Franca et al. (2002, ApJ, 570, 100 = LF02), the USNO-A2.0 1 optical catalog, the APM 2 optical catalog and the NASA Extragalactic Database (NED). 24 X-ray/radio associations have been identified with sources in LF02 (10 Type 1 AGN, 4 Type 2 AGN, 2 BL Lacs, 3 Clusters, 4 ELGs and 1 Radio galaxy), 1 has been identified with a z = 0.708 Radio galaxy in the Lockman Hole using NED (see Table 2 source 116 in Lehmann et al. 2000, A&A, 354, 35 for a description of this source), 13 have an optical (R-band) identification in the USNO and/or APM catalogue while 15 X-ray/radio associations do not have an optical identification brighter than R=20. This table was created by the HEASARC in July 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/342/575">CDS Catalog J/MNRAS/342/575</a> file table1.dat. There was a minor update to the HEASARC's implementation in June 2022 to make the two probability parameters into unitless quantities for improved clarity. This is a service provided by NASA HEASARC . 2003MNRAS.342..575C https://heasarc.gsfc.nasa.gov/W3Browse/all/saxhellasr.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=saxhellasr& GET text/xml 180 99999 true 95.98583333 -69.35361111 0.0333333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=saxhellasr GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_saxhellasr&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0333333333333333 Optical Radio X-ray public saxhellasr BeppoSAX High-Energy Large Area Survey (HELLAS) Radio Source Cat 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 flux X-Ray Flux at 5-10 keV erg/s/cm^2 phot.flux;em.X-ray.medium double nullable radio_ra Right Ascension of Radio Source degree pos.eq.ra;em.radio double nullable radio_dec Declination of Radio Source degree pos.eq.dec;em.radio double nullable flux_5_ghz_limit Limit Flag for Flux Density at 5 GHz meta.code;phot.flux.density;em.radio.3-6GHz char nullable flux_5_ghz Flux Density at 5 GHz (6 cm) from NVSS v2.17 mJy phot.flux.density;em.radio.3-6GHz double nullable flux_5_ghz_error RMS Uncertainty in F5GHz mJy stat.error;phot.flux.density;em.radio.3-6GHz double nullable flux_8p6_ghz_limit Limit Flag for Flux Density at 8.6 GHz meta.code;phot.flux.density;em.radio.6-12GHz char nullable flux_8p6_ghz Flux Density at 8.6 GHz mJy phot.flux.density;em.radio.6-12GHz double nullable flux_8p6_ghz_error RMS Uncertainty in Flux Density at 8.6 GHz mJy stat.error;phot.flux.density;em.radio.6-12GHz 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 radio_optical_offset Distance Between Radio and Optical Positions arcsec pos.angDistance;em.radio;em.opt double nullable xr_random_assoc_prob Probability of a Random X-Ray/Radio Association stat.probability double nullable ref_rmag Flag [alu] Indicates Reference for Rmag meta.ref;phot.mag;em.opt.R char nullable flux_1p4_ghz_flag Flag [n] Indicates 1.4GHz Flux Density Not from NVSS v2.17 meta.code;phot.flux.density;em.radio.750-1500MHz char nullable flux_1p4_ghz_limit Limit Flag for F1.4GHz meta.code;phot.flux.density;em.radio.750-1500MHz char nullable ro_spectral_index Two-Point Radio-to-Optical Spectral Index spect.index;em.radio;em.opt double nullable ro_spectral_index_limit Limit Flag for Two-Point Radio-to-Optical Spectral Index meta.code;spect.index;em.radio;em.opt char nullable source_type Flag [0-6] Indicates Spectroscopic Identification src.class short nullable flux_5_ghz_flag [n] n: not from NVSS v2.17 meta.code;phot.flux.density;em.radio.3-6GHz char nullable xray_radio_offset Distance Between X-Ray and Radio Positions arcsec pos.angDistance;em.X-ray;em.radio double nullable rad_spectral_index_limit Limit Flag for Spectral Index meta.code;spect.index;em.radio char nullable ox_spectral_index Two-Point Optical-to-X-Ray Spectral Index spect.index;em.opt;em.X-ray double nullable bii Galactic Latitude degree pos.galactic.lat double nullable rmag_limit Limit Flag for Rmag meta.code;phot.mag;em.opt.R char nullable flux_1p4_ghz_error RMS Uncertainty in Flux Density at 1.4 GHz mJy stat.error;phot.flux.density;em.radio.750-1500MHz double nullable flux_8p6_ghz_flag Flag [n] Indicates Note Concerning Flux Density at 8.6 GHz meta.code;phot.flux.density;em.radio.6-12GHz char nullable rmag R-Band Magnitude, from La Franca et al., Cat. <J/ApJ/570/100> mag phot.mag;em.opt.R double nullable hellas_id HELLAS Identification Number meta.id char nullable ro_random_assoc_prob Probability of a Random Radio/Optical Association stat.probability double nullable class Browse Object Classification src.class short nullable lii Galactic Longitude degree pos.galactic.lon double nullable flux_1p4_ghz Flux Density at 1.4 GHz (20 cm), from NVSS v2.17 mJy phot.flux.density;em.radio.750-1500MHz double nullable redshift Redshift from La Franca et al., Cat. <J/ApJ/570/100> src.redshift double nullable ox_spectral_index_limit Limit Flag for Two-Point Optical-to-X-Ray Spectral Index meta.code;spect.index;em.opt;em.X-ray char nullable ref_source_type Flag [l] Indicates Source Type (and z) from Lehmann et al., 2000A&A...354...35L meta.ref;src.class char nullable rad_spectral_index Radio Spectral Index Calculated Using Available Frequencies (Mainly 6 and 20 cm) spect.index;em.radio double nullable off_axis Offset in the BeppoSAX Field arcmin instr.offset double nullable