학술논문
VERA Observation of the W49NH2O Maser Outburst in 2003 October
Document Type
Article
Author
Mareki, Honma; Choi, Yoon Kyung; Bushimata, Takeshi; Fujii, Takahiro; Hirota, Tomoya; Horiai, Koji; Imai, Hiroshi; Inomata, Noritomo; Ishitsuka, Jose; Iwadate, Kenzaburo; Jike, Takaaki; Kameya, Osamu; Kamohara, Ryuichi; Kan-ya, Yukitoshi; Kawaguchi, Noriyuki; Kobayashi, Hideyuki; Kuji, Seisuke; Kurayama, Tomoharu; Manabe, Seiji; Miyaji, Takeshi; Nakagawa, Akiharu; Nakashima, Kouichirou; Nagayoshi, Riiko; Omodaka, Toshihiro; Oyama, Tomoaki; Rioja, Maria; Sakai, Satoshi; Sakakibara, Sei-ichiro; Sato, Katsuhisa; Sasao, Tetsuo; Shibata, Katsunori M.; Shimizu, Rie; Sora, Kasumi; Suda, Hiroshi; Tamura, Yoshiaki; Yamashita, Kazuyoshi
Source
Publications of the Astronomical Society of Japan; June 2004, Vol. 56 Issue: 3 pL15-L18, 4p
Subject
Language
ISSN
00046264; 2053051X
Abstract
We report on a strong outburst of the W 49N $\mathrm{H}_2 \mathrm{O}$maser observed with VERA. Single-dish monitoring with VERA 20m telescopes detected a strong outburst of the maser feature at $V_\mathrm{LSR} =-30.7 \,\mathrm{km} \,\mathrm{s}^{-1}$in 2003 October. The outburst had a duration of $\sim 100$days and a peak intensity of $7.9 \times 10^4 \,\mathrm{Jy}$, being one of the strongest outbursts in W 49N observed so far. VLBI observations with the VERA array were also carried out near to the maximum phase of the outburst, and the outburst spot was identified in the VLBI map. While the map was in good agreement with previous studies, showing three major concentrations of maser spots, we found a newly formed arc-like structure in the central maser concentration, which may be a shock front powered by a forming star or a star cluster. The outburst spot was found to be located on the arc-like structure, indicating a possible connection of the present outburst to a shock phenomenon.