J/A+A/634/A112ivo://CDS.VizieR/J/A+A/634/A112doi:10.26093/cds/vizier.36340112CDSTraianou E.Krichbaum T.P.Boccardi B.Angioni R.Rani B.Liu J.,Ros E.Bach U.Sokolovsky K.V.Lisakov M.M.Kiehlmann S.Gurwell M.,Zensus J.A.2020-08-19T13:05:10Z2020-02-19T08:05:20ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsgamma-ray-astronomyvery-long-baseline-interferometryThe gamma-ray production mechanism and its localization in blazars are still a matter of debate. The main goal of this paper is to constrain the location of the high-energy emission in the blazar TXS 2013+370 and to study the physical and geometrical properties of the inner jet region on sub-pc scales. TXS 2013+370 was monitored during 2002-2013 with VLBI at 15, 22, 43, and 86GHz, which allowed us to image the jet base with an angular resolution of >=0.4pc. By employing CLEAN imaging and Gaussian model-fitting, we performed a thorough kinematic analysis at multiple frequencies, which provided estimates of the jet speed, orientation, and component ejection times. Additionally, we studied the jet expansion profile and used the information on the jet geometry to estimate the location of the jet apex. VLBI data were combined with single-dish measurements to search for correlated activity between the radio, mm, and gamma-ray emission. For this purpose, we employed a cross-correlation analysis, supported by several significance tests. The high-resolution VLBI imaging revealed the existence of a spatially bent jet, described by co-existing moving emission features and stationary features. New jet features, labeled as A1, N, and N1, are observed to emerge from the core, accompanied by flaring activity in radio/mm- bands and rays. The analysis of the transverse jet width profile constrains the location of the mm core to lie <=2pc downstream of the jet apex, and also reveals the existence of a transition from parabolic to conical jet expansion at a distance of ~54pc from the core, corresponding to ~1.5x10^6^ Schwarzschild radii. The cross-correlation analysis of the broad-band variability reveals a strong correlation between the radio-mm and gamma-ray data, with the 1mm emission lagging 49 days behind the rays. Based on this, we infer that the high energy emission is produced at a distance of the order of ~1pc from the VLBI core, suggesting that the seed photon fields for the external Compton mechanism originate either in the dusty torus or in the broad-line region.2020A&A...634A.112Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/634/A112CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/634/A112https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/634/A112http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/634/A112https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/634/A112https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/634/A112http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/634/A112GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/634/A112/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/634/A112/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/634/A112/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/634/A112/list?GETtext/xml+votable180.050000true303.8696437.183250.0055555555555555566/14641https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/634/A112?format=asciiGamma-rayRadiodefaultJ/A+A/634/A112/listList of fits imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datetime.epoch;obsnullableFreqObserved frequencyGHzem.freqfloatEpochObserving year (from table B1)yrtimefloatArrayParticipating antennas (from table B1) (1)meta.id;instrcharbmajMajor axis of the convolving beam (from table B1)masphys.angSizefloatBminMinor axis of the convolving beam (from table B1)masphys.angSize;instr.beamfloatPA[] Position angle (from table B1)degpos.posAngfloatSpeakImage peak flux density (from table B1)Jyphot.flux.density;em.radiofloatrmsNoise level (from table B1)mJy/beaminstr.det.noisefloatStotImage total flux density (from table B1)Jy/beamphot.flux.density;em.radiofloatsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitschar