Astrometry of H2O Masers in Nearby Star-Forming Regions with VERA III. IRAS 22198+6336 in Lynds 1204 G

作者：Hirota Tomoya^*; Ando Kazuma; Bushimata Takeshi; Choi Yoon Kyung; Honma Mareki; Imai Hiroshi; Iwadate Kenzaburo; Jike Takaaki; Kameno Seiji; Kameya Osamu; Kamohara Ryuichi; Kan ya Yukitoshi; Kawaguchi Noriyuki; Kijima Masachika; Kim Mi Kyoung; Kobayashi Hideyuki; Kuji Seisuke; Kurayama Tomoharu; Manabe Seiji; Matsui Makoto; Matsumoto Naoko; Miyaji Takeshi; Miyazaki Atsushi; Nagayama Takumi; Nakagawa Akiharu; Namikawa Daichi; Nyu Daisuke; Oh Chung Sik

来源：Publications of the Astronomical Society of Japan, 2008, 60(5): 961-974.

DOI：10.1093/pasj/60.5.961

• Astrometry
• ISM: individual (Lynds 1204G)
• ISM: jets and outflows
• masers (H2O)
• stars: individual (IRAS 22198+6336)

We present results of multi-epoch VLBI observations with VERA (VLBI Exploration of Radio Astrometry) of the 22 GHz H2O masers associated with a young stellar object (YSO) IRAS22198+6336 in a dark cloud, L 1204 G. Based on phase-referencing VLBI astrometry, we derived an annual parallax of IRAS 22198+6336 to be 1.309 +/- 0.047 mas, corresponding to the distance of 764 27 pc from the Sun. Although the most principal error source of our astrometry is attributed to the internal structure of the maser spots, we successfully reduced the errors in the derived annual parallax by employing position measurements for all of the 26 detected maser spots. Based on this result, we reanalyzed the spectral energy distribution of IRAS 22198+6336 and found that the bolometric luminosity and total mass of IRAS 22198+6336 are 450 L-circle dot and 7 M-circle dot, respectively. These values are consistent with an intermediate-mass YSO deeply embedded in the dense dust core, which has been proposed to be an intermediate-mass counterpart of a low-mass Class 0 source. In addition, we obtained absolute proper motions of the H2O masers for the most blue-shifted components. We propose that the collimated jets aligned along the east-west direction are the most plausible explanation for the origin of the detected maser features.

• 出版日期2008
• 单位中国科学院国家天文台