J/A+A/375/739ivo://CDS.VizieR/J/A+A/375/739doi:10.26093/cds/vizier.33750739CDSDonato D.Ghisellini G.Tagliaferri G.Fossati G.2001-11-07T19:23:09Z2001-11-07T20:23:04ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsquasarsx-ray-sourcesWe have considered all blazars observed in the X-ray band and for which the slope of the X-ray spectrum is available. We have collected 421 spectra of 268 blazars, including 12 archival unpublished ASCA spectra of 7 blazars whose analysis is presented here. The X-ray spectra of blazars show trends as a function of their power, confirming that the blazar overall energy distribution can be parameterized on the basis of one parameter only, i.e. the bolometric luminosity. This is confirmed by the relatively new hard (2-10 keV) X-ray data. Our results confirm the idea that in low power objects the X-ray emission mechanism is the synchrotron process, dominating both the soft and the hard X-ray emissions. Low energy peaked BL Lac objects are intermediate, often showing harder spectra in the hard X-ray band, suggesting that the synchrotron process dominates in the soft band, with the inverse Compton process dominating at high energies. The most powerful objects have X-ray spectra that are flat both in the soft and in the hard band, consistent with a dominating inverse Compton component.2001A&A...375..739Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/375/739CatalogResearchIsServedByTAP VizieR generic servicerelated-toVII/224 : Quasars and Active Galactic Nuclei (10th Ed.) (Veron+ 2001)VIII/5 : Bright Extragalactic Radio Sources (1Jy) (Kuehr+, 1981)J/ApJ/525/127 : RGB sample of BL Lacertae objects (Laurent-Muehleisen+ 1999)J/A+A/311/384 : ROSAT observations of BL Lacertae objects (lamer+ 1996)J/MNRAS/277/1477 : A catalogue of BL Lacertae objects (Padovani+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/375/739https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/375/739http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/375/739https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/375/739https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/375/739http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/375/739GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-raydefaultJ/A+A/375/739/refsReferencesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference codemeta.refcharBibCodeBibCodemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharComCommentsmeta.notecharJ/A+A/375/739/table5Cataloguez? Redshiftsrc.redshiftfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIAU name of the source (based on 1950 positions)meta.id;meta.maincharS5GHz? Radio flux at 5 GHzJyphot.flux.density;em.radio.3-6GHzfloatnullabler_S5GHzReference for the radio flux, in ref.dat filemeta.refcharSoptOptical flux at 5500{AA}mJyphot.flux.density;em.optfloatr_SoptReference for the optical flux, in ref.dat filemeta.refcharSXX-ray flux at 1 keVuJyphot.flux;em.X-rayfloatr_SXReference for the X-ray flux, in ref.dat filemeta.refcharSp+IndexX-ray photon spectral indexspect.indexfloate_Sp+Index? Error on the X-ray spectral indexstat.errorfloatnullabler_Sp+IndexReference for the X-ray spectral index, in ref.dat filemeta.refcharClass[1/3]? Classification of the source (1)src.classintnullabler_ClassReference for class, in ref.dat filemeta.refcharSatObserving satellite (2)meta.id;instrchar