J/A+A/409/79ivo://CDS.VizieR/J/A+A/409/79doi:10.26093/cds/vizier.34090079CDSFiore F.Brusa M.Cocchia F.Baldi A.Carangelo N.Ciliegi P.,Comastri A.La Franca F.Maiolino R.Matt G.Molendi S.Mignoli M.,Perola G.C.Severgnini P.Vignali C.2012-09-24T08:35:00Z2009-01-28T07:41:27ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frx-ray-sourcesquasarsWe present results from the photometric and spectroscopic identification of 122 X-ray sources recently discovered by XMM-Newton in the 2-10keV band (the HELLAS2XMM 1dF sample). Their flux cover the range 8x10^-15^-4x10^-13^erg/cm^2^/s and the total area surveyed is 0.9 square degrees. One of the most interesting results (which is found also in deeper surveys) is that about 20% of the hard X-ray selected sources have an X-ray to optical flux ratio (X/O) ten times or more higher than that of optically selected AGN. Unlike the faint sources found in the ultra-deep Chandra and XMM-Newton surveys, which reach X-ray (and optical) fluxes more than one order of magnitude lower than the HELLAS2XMM survey sources, many of the extreme X/O sources in our sample have R<~25 and are therefore accessible to optical spectroscopy. We report the identification of 13 sources with X/O>~10 (to be compared with 9 sources known from the deeper, pencil-beam surveys). Eight of them are narrow line QSO (seemingly the extension to very high luminosity of the type 2 Seyfert galaxies), four are broad line QSO. The results from our survey are also used to make reliable predictions about the luminosity of the sources not yet spectroscopically identified, both in our sample and in deeper Chandra and XMM-Newton samples. We then use a combined sample of 317 hard X-ray selected sources (HELLAS2XMM 1dF, Chandra Deep Field North 1Msec, Chandra SSA13 and XMM-Newton Lockman Hole flux limited samples), 221 with measured redshifts, to evaluate the cosmological evolution of the hard X-ray source's number and luminosity densities.2003A&A...409...79Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/409/79CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/327/771 : BeppoSAX HELLAS survey. II. (Fiore+, 2001)J/A+A/370/900 : BeppoSAX HELLAS survey. IV (Vignali+, 2001)J/ApJ/570/100 : BeppoSAX HELLAS survey. V. (La Franca+, 2002)J/MNRAS/342/575 : BeppoSAX HELLAS survey. VI. (Ciliegi, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/409/79https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/409/79http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/409/79https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/409/79https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/409/79http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/409/79GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/409/79/table1 (The HELLAS2XMM 1dF sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/409/79/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/409/79/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/409/79/table1?GETtext/xml+votable180.050000true85.251667-28.6513890.0055555555555555566/16591 16879 16890 17221 20657 32961 49042 490482.762881831355591e-19 3.3785437584409506e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/409/79?format=asciiX-raydefaultJ/A+A/409/79/table1The HELLAS2XMM 1dF sampleIDSource identificationmeta.id;meta.maincharn_ID[abcdi] Note (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA2000X-ray right ascension (2000)pos.eq.ra;meta.mainDE2000X-ray declination (2000)pos.eq.dec;meta.mainRAo? Optical (R band) right ascension (2000)pos.eq.ranullableDEo? Optical (R band) declination (2000)pos.eq.decnullableDist? Separation between the X-ray and optical positionsarcsecpos.angDistancefloatnullableFx2-10keV flux (10^-14^erg/cm^2^/s)1e-17W.m**-2phot.flux;em.X-rayfloatRmagR magnitudemagphot.mag;em.opt.RfloatClassClassification of the optical spectrum (2)src.classcharn_Class[efgh] Note on Class (3)meta.notecharz? Redshiftsrc.redshiftfloatnullablen_z[l] Note on redshift (4)meta.notecharlogLx? 2-10keV luminositylog(1e-07W)phys.luminosity;em.X-rayfloatnullable_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexed