Multi-Frequency VLBI Observations of OT 081

[摘要] WehaveobservedOT081at4.8,8.4,15,and22GHz,withtheVLBISpaceObservatoryProgramme(VSOP)andtheVery-Long-BaselineArray(VLBA)afteritsradioburston1998May.Multi-frequencyVLBIimagesshowadominantcomponentDandaweakcomponentC1,whichisaknotofthejetextendingtothenorth-westdirection.ThederivedphysicalparametersofcomponentDaretheDopplerfactor,δeq∼32.0,theLorentzfactorof16.0lt;Γlt;16.9,andtheviewingangle,φlt;°.68.ItappearsthatalthoughδeqofcomponentC1issmallarthanthatofcomponetDbyoneorderofmagnitude,ΓofcomponentC1isabouttwicetherangeasthatofcomponentDatthe1σlevel.However,φofcomponentDisdifferentfromthatofcomponentC1.TherapidvariabilityofthefluxdensityofOT081issuggestedtobeduetothevariationofφ.

[学科分类] 天文学(综合)

[关键词] "BL Lacertae objects: individual (OT 081 = 1749+096)";"galaxies: active";"radio sources: variable";"techniques: interferometric"