J/MNRAS/540/364ivo://CDS.VizieR/J/MNRAS/540/364doi:10.26093/cds/vizier.75400364CDSAbe H.Abe S.Acciari V.A.Agudo I.Aniello T.Ansoldi S.,Antonelli L.A.Arbet Engels A.Arcaro C.Artero M.Asano K.Baack D.,Babic A.Baquero A.Barres De Almeida U.Batkovic I.Baxter J.,Bernardini E.Bernardos M.Bernete J.Berti A.Bigongiari C.,Biland A.Blanch O.Bonnoli G.Bosnjak Z.Burelli I.Busetto G.,Campoy-Ordaz A.Carosi A.Carosi R.Carretero-castrillo M.,Castro-Tirado A.J.Chai Y.Cifuentes A.Cikota S.Colombo E.,Contreras J.L.Cortina J.Covino S.D'amico G.D'Elia V.Da Vela P.,Dazzi F.De Angelis A.De Lotto B.Del Popolo A.Delfino M.,Delgado J.Delgado Mendez C.Depaoli D.Di Pierro F.Di Venere L.,Dominis Prester D.Donini A.Dorner D.Doro M.Elsaesser D.Emery G.,Escudero J.Farina L.Fattorini A.Foffano L.Font L.Fukami S.,Fukazawa Y.Garcia Lopez R.J.Gasparyan S.Gaug M.,Giesbrecht Paiva J.G.Giglietto N.Giordano F.Gliwny P.Grau R.,Green J.G.Hadasch D.Hahn A.Heckmann L.Herrera J.Hrupec D.,Hutten M.Imazawa R.Inada T.Iotov R.Ishio K.Jimenez Martinez I.,Jormanainen J.Kerszberg D.Kluge G.W.Kobayashi Y.Kubo H.,Kushida J.Lainez Lezaun M.Lamastra A.Leone F.Lindfors E.,Linhoff L.Lombardi S.Longo F.Lopez-moya M.Lopez-Oramas A.,Loporchio S.Lorini A.Machado De Oliveira Fraga B.Majumdar P.,Makariev M.Maneva G.Mang N.Manganaro M.Mangano S.Mannheim K.,Mariotti M.Martinez M.Mas-aguilar A.Mazin D.Menchiari S.,Mender S.Micanovic S.Miceli D.Miranda J.M.Mirzoyan R.Molina E.,Mondal H.A.Morcuende D.Nanci C.Neustroev V.Nigro C.Nishijima K.,Njoh Ekoume T.Noda K.Nozaki S.Ohtani Y.Otero-santos J.Paiano S.,Palatiello M.Paneque D.Paoletti R.Paredes J.M.Pavletic L.,Persic M.Pihet M.Pirola G.Podobnik F.Prada Moroni P.G.,Prandini E.Principe G.Priyadarshi C.Rhode W.Ribo M.Rico J.,Righi C.Sahakyan N.Saito T.Satalecka K.Saturni F.G.Schleicher B.,Schmidt K.Schmuckermaier F.Schubert J.L.Schweizer T.Sitarek J.,Spolon A.Stamerra A.Striskovic J.Strom D.Suda Y.Suric T.,Suutarinen S.Tajima H.Takahashi M.Takeishi R.Tavecchio F.,Temnikov P.Terzic T.Teshima M.Tosti L.Truzzi S.Ubach S.,Van Scherpenberg J.Ventura S.Verguilov V.Viale I.Vigorito C.F.,Vitale V.Walter R.Yamamoto T. (MAGIC Collaboration)Ait Benkhali F.,Becherini Y.Bi B.Bottcher M.Bolmont J.Brown A.Bulik T.,Casanova S.Chand T.Chandra S.Chibueze J.Chibueze O.Egberts K.,Einecke S.Ernenwein J.-P.Fontaine G.Gabici S.Goswami P.Holler M.,Jamrozy M.Joshi V.Kasai E.Katarzynski K.Khatoon R.Khelifi B.,Kluzniak W.Kosack K.Lang R.G.Le Stum S.Lemiere A.Marx R.,Moderski R.Moghadam M.O.De Naurois M.Niemiec J.O'Brien P.,Ostrowski M.Peron G.Pita S.Puhlhofer G.Quirrenbach A.Rudak B.,Sahakian V.Sanchez D.A.Santangelo A.Sasaki M.Schutte H.M.,Seglar-arroyo M.Shapopi J.N.S.Steenkamp R.Steppa C.Suzuki H.,Tanaka T.Tluczykont M.Venter C.Wagner S.J.Wierzcholska A.,Zdziarski A.A.Zywucka N. (VHE Gamma-ray collaborators),Becerra Gonzalez J.Ciprini S.Venters T.M. (from the Fermi-LATCollaboration)D'Ammando F.Esteban-Gutierrez A.Fallah Ramazani V.,Filippenko A.V.Hovatta T.Jermak H.Jorstad S.Kiehlmann S.,Lahteenmaki A.Larionov V.M.Larionova E.Marscher A.P.Morozova D.,Max-Moerbeck W.Readhead A.C.S.Reeves R.Steele I.A.Tornikoski M.,Verrecchia F.Xiao H.B.Zheng W. (MWL collaborators)2025-10-10T20:12:20Z2025-06-27T15:19:57ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiphotometryvisible-astronomygamma-ray-astronomyradio-sourcesspectral-energy-distributionOT 081 is a well-known, luminous blazar that is remarkably variable in many energy bands. We present the first broadband study of the source, which includes very high energy (VHE, E>100GeV) {gamma}-ray data taken by the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov telescopes) and H.E.S.S. (High Energy Stereoscopic System) imaging Cherenkov telescopes. The discovery of VHE {gamma}-ray emission happened during a high state of {gamma}-ray activity in July 2016, observed by many instruments from radio to VHE {gamma}-rays. We identify four states of activity of the source, one of which includes VHE {gamma}-ray emission. Variability in the VHE domain is found on daily time-scales. The intrinsic VHE spectrum can be described by a power law with index 3.27+/-0.44stat+/-0.15sys (MAGIC) and 3.39+/-0.58stat+/-0.64sys (H.E.S.S.) in the energy range of 55-300 and 120-500GeV, respectively. The broadband emission cannot be successfully reproduced by a simple one-zone synchrotron self-Compton model. Instead, an additional external Compton component is required. We test a lepto-hadronic model that reproduces the data set well and a proton-synchrotron-dominated model that requires an extreme proton luminosity. Emission models that are able to successfully represent the data place the emitting region well outside of the broad-line region to a location at which the radiative environment is dominated by the infrared thermal radiation field of the dusty torus. In the scenario described by this flaring activity, the source appears to be a flat spectrum radio quasar (FSRQ), in contrast with past categorizations. This suggests that the source can be considered to be a transitional blazar, intermediate between BL Lac and FSRQ objects.2025MNRAS.540..364Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/540/364CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/540/364https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/540/364http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/540/364https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/540/364https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/540/364http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/540/364GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-rayOpticalRadiodefaultJ/MNRAS/540/364/table1*Parameters of the power-law fit to the VHE gamma-ray spectra observed by MAGIC and H.E.S.S. (this work)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument (MAGIC or HESS)meta.id;instrcharTobsObservation time, or observation time interval (MJD)dtime.epochcharteff? Effective observing timehtime.expofloatnullableTypeType, observed (obs.) or intrinsic (intr.)meta.note;src.morph.typecharEminMinimum energy for the extraction of spectral parametersGeVphys.energy;stat.minintEdecDecorrelation energyGeVstat.correlationintGammaPhoton indexmeta.code;spect.indexfloatF0Flux at decorrelation energycm**-2.s**-1.TeV**-1phot.flux.density;em.gamma.harddoublee_F0Flux at decorrelation energy statistical errorcm**-2.s**-1.TeV**-1stat.errordoubles_F0Flux at decorrelation energy systematic errorcm**-2.s**-1.TeV**-1stat.correlationdoublee_GammaPhoton index statistical errorstat.errorfloatE_GammaPhoton index systematic errorstat.error;stat.maxfloatF200GeVFlux at 200GeVcm**-2.s**-1.TeV**-1phot.flux.density;em.gamma.harddoublee_F200GeVFlux at 200GeV statistical errorcm**-2.s**-1.TeV**-1stat.errordoubles_F200GeVFlux at 200GeV systematic errorcm**-2.s**-1.TeV**-1stat.error.sys;phot.fluxdoubleJ/MNRAS/540/364/fig2aMWL light curves of OT 081 during the period from MJD 57575 to MJD 57602 (2016 July 6-August 2), fluxesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument (1)meta.id;instrcharMJDObservation datedtime.epochdoublee_MJD? Error on MJD (only for HESS and MAGIC data)dstat.error;time.epochdoublenullableFluxFluxphot.fluxdoublee_FluxFlux errorstat.error;phot.fluxdoubleBandBandinstr.bandpasscharx_FluxUnits of Fluxmeta.unit;phot.fluxJ/MNRAS/540/364/fig2bMWL light curves of OT 081 during the period from MJD 57575 to MJD 57602 (2016 July 6-August 2), polarisationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument (1)meta.id;instrcharMJDObservation datedtime.epochdoublePolPolarisation percentage%phys.polarizationfloate_PolPolarisation percentage error%stat.errorfloatJ/MNRAS/540/364/fig2cMWL light curves of OT 081 during the period from MJD 57575 to MJD 57602 (2016 July 6-August 2), electric vector polarisation anglerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument (1)meta.id;instrcharMJDObservation datedtime.epochdoubleEVPAElectric vector polarisation angledegphys.electFieldfloate_EVPAElectric vector polarisation angle error%stat.errorfloatJ/MNRAS/540/364/fig4aOT081 simultaneous data for the first point high state in Fermi (MJD 57589.5) (P2)e_SED? Spectral energy distribution lower errorTeV.cm**-2.s**-1stat.errordoublenullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument (1)meta.id;instrcharEEnergyGeVem.energydoublel_SEDLimit flag on SEDmeta.code.errorcharSEDSpectral energy distributionTeV.cm**-2.s**-1phot.fluxdoubleE_SED? Spectral energy distribution upper errorTeV.cm**-2.s**-1stat.error;stat.maxdoublenullableJ/MNRAS/540/364/fig4bOT081 broadband data for the flare in VHE. 23-24th of July (MJD 57592-57593) (P3)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument (1)meta.id;instrcharEEnergyGeVem.energydoublel_SEDLimit flag on SEDmeta.code.errorcharSEDSpectral energy distributionTeV.cm**-2.s**-1phot.fluxdoubleE_SED? Spectral energy distribution upper errorTeV.cm**-2.s**-1stat.error;stat.maxdoublenullablee_SED? Spectral energy distribution lower errorTeV.cm**-2.s**-1stat.errordoublenullableJ/MNRAS/540/364/fig4cOT081 Simultaneous data for the low state in VHE (MJD 57594-57596) (P4)InstInstrument (1)meta.id;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEEnergyGeVem.energydoublel_SEDLimit flag on SEDmeta.code.errorcharSEDSpectral energy distributionTeV.cm**-2.s**-1phot.fluxdoubleE_SED? Spectral energy distribution upper errorTeV.cm**-2.s**-1stat.error;stat.maxdoublenullablee_SED? Spectral energy distribution lower errorTeV.cm**-2.s**-1stat.errordoublenullable