On the Detection of Solar Coronal High-Velocity Fields Using the XUV Doppler Telescope

[摘要] TheXUVDopplerTelescope(XDT)isasoundingrocketexperimentdesignedtodetectflowsinthesolarcoronausingfilterratios.TheXDT,successfullylaunchedon1998January31,isanormalincidencetelescopecomposedofnarrow-bandpassmultilayermirrorsandcapableofobtainingimages2Ã…aboveand2Ã…belowtheFeXIV211Ã…(T=1.7MK)emissionline.Ithasthepotentialtomakeavelocitymapoftheentiresolardiskwithjustafewminutesofobservation.TheimageratiomapsshowfeaturesthattranslatetoDopplershiftsof200kms−1ormore,includingseveral`redshift'featureslocatednearfootpointsofcoronalloops.However,nocorrespondingvelocityfeatureswereseenbytheSolarandHeliosphericObservatory(SOHO)CoronalDiagnosticSpectrometer(CDS)intheMgIX368Ã…(T=1MK)line,suggestingthatthefeaturesarenotcausedbyDopplershift.Instead,thefeaturesseemtoberelatedtocontaminationoflowertemperature(Tlt;1MK)emissionlinesandthenearbydensity-sensitiveFeXIIIlines.WeconcludethatwhilenoflowswerepositivelyidentifiedbytheXDT,thisobservingtechniqueiscapableofdetectingflowsof1000kms−1independently,and200kms−1whencombinedwithsimultaneousplasmadiagnosticobservation.

[学科分类] 天文学(综合)

[关键词] "Sun: atmosphere";"Sun: corona";"Sun: X-rays"