Access to Astronomical Catalogues

← Click to display the menu
J/A+A/472/699  ROXA: multi-frequency large sample of blazars (Turriziani+, 2007)

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
ADC_Keywords: Active gal. nuclei ; BL Lac objects ; QSOs Keywords: galaxies: BL Lacertae objects: general - quasars: general - methods: statistical - catalogs Abstract: Although Blazars are a small fraction of the overall AGN population they are expected to be the dominant population of extragalactic sources in the hard X-ray and gamma-ray bands and have been shown to be the largest contaminant of CMB fluctuation maps. So far the number of known blazars is of the order of several hundreds, but the forthcoming AGILE, GLAST and Planck space observatories will detect several thousand of objects of this type. In preparation for these missions it is necessary to identify new samples of blazars to study their multi-frequency characteristics and statistical properties. We compiled a sample of objects with blazar-like properties via a cross-correlation between large radio (NVSS, ATCAPMN) and X-ray surveys (RASS) using the SDSS-DR4 and 2dF survey data to spectroscopically identify our candidates and test the validity of the selection method. We present the Radio-Optical-X-ray catalog built at ASDC (ROXA), a list of 816 objects among which 510 are confirmed blazars. Only 19% of the candidates turned out to be certainly non-blazars demonstrating the high efficiency of our selection method. Our catalog includes 173 new blazar identifications, or about 10% of all presently known blazars. The relatively high flux threshold in the X-ray energy band (given by the RASS survey) preferentially selects objects with high FX/Fr ratio leading to the discovery of new High Energy Peaked BL Lac (HBLs).Our catalog therefore includes many new potential targets for GeV-TeV observations. Description: A list of 816 objects among which 510 are confirmed blazars. The selection method consists in 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 we calculated the X-ray to optical (alphaox) and radio to optical (alpharo) spectral slopes and took only sources with alphaox and alpharo values within the blazar area. For each object, redshift, B and G magnitudes, radio flux at 1.4GHz and at 5GHz, X-ray flux, FX/Fr ratio, X-ray luminosity, radio luminosity, CaH&K break and classification are given. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file catalog.dat 114 816 ROXA catalog of blazars.
See also: VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998) IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000) IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999) II/276 : The SDSS Photometric Catalog, Release 5 (Adelman-McCarthy + 2007) VII/226 : The 2dF Galaxy Redshift Survey 100k Data Release (2dFGRS Team, 2001) VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004) ATCAPMN : Byte-by-byte Description of file: catalog.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [ROXA] 5- 22 A18 --- ROXA Source name (JHHMMSS.s+DDMMSS.s) 24- 27 F4.2 --- z Redshift 29- 32 F4.1 mag Bjmag ?=0 Bj magnitude (from 2dF surveys) 34- 37 F4.1 mag g'mag ?=0 g' magnitude (from SDSS survey) 39- 45 F7.1 mJy F1.4GHz ?=0 Radio flux at 1.4GHz (NVSS) 47- 53 F7.1 mJy F5GHz ?=0 Radio flux at 5GHz (North6cm, GB6 and PMN) 55- 62 E8.3 mW/m2 FX X-ray Flux (RASS) 64- 71 E8.3 mW/m2/Jy FX/Fr Ratio between X-ray flux and radio flux 73- 80 E8.3 10-7W LX X-ray Luminosity 82- 89 E8.3 10-7W/Hz Lr Radio Luminosity 91- 94 F4.2 --- CaH+K ? Calcium Break 96-111 A16 --- Class Classification (1) 113-114 A2 --- n_Class [*@z] Note on Class (2)
Note (1): Classification as follows: 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 Note (2): We identify new objects with three different labels as follows: * = new classification for those objects differently classified in literature @ = new object (never identified before this work) z = objects with newly estimated redshifts
Acknowledgements: Elisabetta Cavazzuti, elisabetta.cavazzuti(at)
(End) Patricia Vannier [CDS] 31-May-2007
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service