J/A+A/631/A150ivo://CDS.VizieR/J/A+A/631/A150doi:10.26093/cds/vizier.36310150CDSMarchesini E.J.Paggi A.Massaro F.Masetti N.D'Abrusco R.,Andruchow I.de Menezes R.2020-01-27T08:34:18Z2019-11-13T06:46:38ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsx-ray-sourcesgamma-ray-astronomyinfrared-photometryBL Lac objects are an extreme type of active galactic nuclei (AGNs) that belong to the largest population of gamma-ray sources: blazars. This class of AGNs shows a double-bumped spectral energy distribution that is commonly described in terms of a synchrotron self-Compton (SSC) emission process, whereas the low-energy component that dominates their emission between the infrared and the X-ray band is tightly connected to the high-energy component that peaks in the gamma-rays. Two strong connections that link radio and mid-infrared emission of blazars to the emission in the gamma-ray band are well established. They constitute the basis for associating gamma-ray sources with their low-energy counterparts. We searched for a possible link between X-ray and gamma-ray emissions for the subclass of BL Lacs using all archival Swift/XRT observations combined with Fermi data for a selected sample of 351 sources. Analyzing ~2400ks of Swift/XRT observations that were carried out until December 2018, we discovered that above the gamma-ray flux threshold Fgamma~=3x10^-12^erg/cm^2^/s, 96% of all Fermi BL Lacs have an X-ray counterpart that is detected with signal-to-noise ratio >3. We did not find any correlation or clear trend between X-ray and gamma-ray fluxes and/or spectral shapes, but we discovered a correlation between the X-ray flux and the mid-infrared color. Finally, we discuss on a possible interpretation of our results in the SSC framework.2019A&A...631A.150Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/631/A150CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/274 : The Roma BZCAT - 5th edition (Massaro+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/631/A150https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/631/A150http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/631/A150https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/631/A150https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/631/A150http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/631/A150GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/631/A150/table1 (Main results of our analysis)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/631/A150/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/631/A150/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/631/A150/table1?GETtext/xml+votable180.050000true0.325-7.7740777780.0055555555555555566/447 716 770 851 1915 2094 2100 2122 2340 2808 3569 3616 3629 3876 3882 4255 4261 4312 4475 4801 4863 4865 4960 5072 5156 5284 5311 5516 5522 5614 5723 5872 5990 6015 6021 6067 6088 6096 6636 6723 6815 6822 6963 6996 7091 7233 7235 7296 7315 7343 7354 7380 7640 7699 7758 8067 8071 8100 8290 8321 8374 8487 8515 8556 8595 8615 8746 8762 8945 8955 9013 9196 9566 9773 10071 10119 10198 10280 10389 10512 10524 10572 10800-10801 10843 10921 10949 11012 11100 11143 11153 11242 11321 11323 11374 11396 11430 11444 11522 11639 11912 11936 11975 12179 12218 12231 12323 12599 13179 13353 13613 13640 13664 13711 13743 14797 14857 14955 15059 15211 15269 15305 15916-15917 15996 15998 16170 16272 16281 16447 16510 16532 16606 16665 16736 16796 16816 17048 17146 17206 17347 17516 17537 17602 17775 17842 17917 18119 18210 18253 18259 18270 18402 18491 18889 19023 19042 19143 19190 19200 19487 19523 19616 19724 19756 19789 19890 19907 19999 20141 20202 20456 20777 20888 21073 21160 21179 21493 21704 21793 23011 23105 23181 23436 23835 23932 24566 24744 24785 24902 25061 25239 25409 25519 25910 26083 26242 26254 26276 26483 26539 26550 26565 26595 26626 26695 26798 26964 26983 27056 27138 27217 27311 27329 27472 27523-27524 27716 27846 27945 28101 28117 28199 28225 28342 28352 28542 29017 29620 29772 29952 30012 30015 30036 30573 31362 31485 31656 32174 32261 32311 32605 32611 32904 33198 33356 33370 33467 33506 33528 33744 33865 33880 33898 33968 34038 34317 34437 34461 34520 34747 35063 35074 35076 35146 35199 35252 35301 35333 35342 35700 35722 35786 35963 35981 36033 36155 36295 36342 36719 36770 36882 36941 37529 37994 38355 38481 38797 38868 39466 39978 40353 40689 40692 40766 40811 40874 40885 41363 42515 42571 42914 43122 43447 43596-43597 43883 44059 44170 44340 44592 44813 45038 45482 46142 46204 46258 46370 46740 46787 47057 47248 47319 47413 47708 47714 47969 48245 48419 48624 48985 49037 491411.6553710307751707e-20 5.842484042127199e-20https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/631/A150?format=asciiGamma-rayX-rayInfrareddefaultJ/A+A/631/A150/table1Main results of our analysisrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceBZCat source name (5BZB JHHMM+DDMM)meta.id;meta.maincharCSoftTotal counts in soft (0.5-2.0keV) bandphphot.count;em.X-ray.softdoublee_CSoftrms uncertainty in CSoftphstat.error;phot.count;em.X-ray.softfloatCHardTotal counts in hard (2.0-10keV) bandphphot.count;em.X-ray.harddoublee_CHardrms uncertainty in CHardphstat.error;phot.count;em.X-ray.hardfloatFluxFlux in total band (0.5-10keV)1e-15W.m**-2phot.fluxfloate_Fluxrms uncertainty in Flux1e-15W.m**-2stat.error;phot.fluxfloatW1mag? Wise W1 (3.4um) magnitudemagphot.mag;em.IR.3-4umfloatnullablee_W1mag? rms uncertainty in W1magmagstat.error;phot.magfloatnullableW2mag? Wise W2 (4.6um) magnitudemagphot.mag;em.IR.4-8umfloatnullablee_W2mag? rms uncertainty in W2magmagstat.error;phot.magfloatnullableW3mag? Wise W3 (12um) magnitudemagphot.flux.density;em.IR.8-15umfloatnullablee_W3mag? rms uncertainty in W3magmagstat.error;phot.magfloatnullableFX/S1.4? X-ray to 1.4GHz flux ratiophot.flux.density;em.radio.750-1500MHzfloatnullableu_FX/S1.4[?] Uncertainty flag on FX/S1.4meta.code.errorcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from BScat (Cat. VII/274) (right ascension part)degpos.eq.ra;meta.main_DEPositions from BScat (Cat. VII/274) (declination part)degpos.eq.dec;meta.main