Relative Astrometry of the J = 1→0, v = 1 and v = 2 SiO Masers toward R Leonis Minoris Using VERA

Publications of the Astronomical Society of Japan

Bujarrabal, Valentín³  Dodson, Richard²  Rioja, María J.¹  Kamohara, Ryuichi⁴  Colomer, Francisco³  Kobayashi, Hideyuki⁴ 

[1] School of Physics, University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia;Observatorio Astronómico Nacional, Apdo. 112, E-28803 Alcalá de Henares, Madrid, Spain School of Physics, University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia;Observatorio Astronómico Nacional, Apdo. 112, E-28803 Alcalá de Henares, Madrid, Spain;VERA Project Office, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588

关键词: "masers (SiO)";    "stars: AGB and post-AGB";    "circumstellar matter";    "stars: late-type";    VERA;   

DOI  :  10.1093/pasj/60.5.1031

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

Oxygen-richAsymptoticGiantBranch(AGB)starsareintenseemittersofSiOandH$$_2$$Omaserlinesat43($$J=$$1$$ightarrow$$0,$$v=$$1and2)and22GHz,respectively.VLBIobservationsofthemaseremissionprovideauniquetooltosampletheinnermostlayersofthecircumstellarenvelopesinAGBstars.Nevertheless,thedifficultiesinachievingastrometricallyaligned$$v=$$1and$$v=$$2SiOmasermapshavetraditionallypreventedauniqueinterpretationoftheobservationsintermsofthephysicalunderlyingconditions,whichdependonthenatureoftheSiOpumpingmechanism.WehavecarriedoutobservationsoftheSiOandH$$_2$$OmaseremissiontowardsRLMi,usingtheastrometriccapabilitiesofVERA.Duetothetooweakemissionofthereferencecalibrator,wehadtodevelopaspecialmethodtoaccuratelyrelatethecoordinatesforbothtransitions.Wepresentrelativeastrometricallyaligned$$v=$$1and$$v=$$2$$J=$$1$$ightarrow$$0SiOmasermaps,atmultipleepochs,anddiscusstheastrophysicalresults.TheincorporationofastrometricinformationintothemapsofSiOmaserschallengestheweakpointsinthecurrenttheoreticalmodels,whichwillneedfurtherrefinementstoaddresstheobservationresults.

【 授权许可】

Unknown