Bigradient Phase Referencing

Publications of the Astronomical Society of Japan

Sudou, Hiroshi²  Honma, Mareki⁶  Habe, Asao³  Omodaka, Toshihiro⁷  Kawaguchi, Noriyuki⁶  Murata, Yasuhiro¹  Takaba, Hiroshi²  Doi, Akihiro⁵  Fujisawa, Kenta⁵  Kobayashi, Hideyuki⁴ 

[1]The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510Department of Space and Astronautical Science, The Graduate University for Advanced Studies, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510

[2]Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193

[3]Division of Physics, Graduate School of Science, Hokkaido University, N10W8, Sapporo, Hokkaido 060-0810

[4]National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588Mizusawa VERA Observatory, 2-12 Hoshigaoka, Mizusawa, Iwate 023-0861

[5]Faculty of Science, Yamaguchi University, 1667-1 Yoshida, Yamaguchi, Yamaguchi 753-8512

[6]National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588Department of Astronomical Science, Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-8588

[7]Faculty of Science, Kagoshima University, 1-21-30 Korimoto, Kagoshima, Kagoshima 890-0065

关键词: astrometry;    "atmospheric effects";    phase-referencing;    "techniques: interferometric";    "very-long-baseline interferometry";   

DOI  :  10.1093/pasj/58.4.777

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

Weproposebigradientphasereferencing(BPR),anewradio-observationtechnique,andreportonitsperformanceusingtheJapanesevery-long-baseline-interferometrynetwork(JVN).Inthismethod,aweaksourceisdetectedbyphase-referencingusingaprimarycalibrator,inordertoplayaroleasasecondarycalibratorforphase-referencingtoaweaktarget.Wewillbegiventheopportunitytoselectacalibratorfromlotsofmilli-Janskysources,oneofwhichmaybelocatedatapositionclosertothetarget.Withsuchasmallerseparation,high-qualityphase-referencingcanbeachieved.Asubsequentmore-sophisticatedcalibrationcanrelocatethearray’sfocustoahypotheticalpointmuchclosertothetarget;ahigherqualityofphasereferencingisavailable.OurdemonstrativeobservationswithstrongradiosourceshaveprovedthecapabilitiesoftheBPRintermsoftheimagedynamicrangesandastrometricreproducibility.Theimagedynamicrangeonatargethasbeenimprovedbyafactorofaboutsixcomparedtothatofnormalphase-referencing;theresultantpositiondifferenceofthetarget’semissionbetweentwoepochswasonly$$62pm50$$microarcsecond,evenwithlessthan2300-kmbaselinesat8.4 GHzandfast-switchingbetweenatarget-calibratorpairseparatedbya$${2lap{.}{}^{mathrm{circ}}1}$$.

【 授权许可】

Unknown