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VLBI observations of H2O masers in the LkHα 234 star-forming region

Published online by Cambridge University Press:  03 August 2017

Tomofumi Umemoto
National Astronomical Observatory, Mitaka, Tokyo 181-8588, Japan
Hiroshi Imai
VERA Projects Office, National Astronomical Observatory, Mitaka, Tokyo 181-8588, Japan
Ray S. Furuya
Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy
Yoshimi Kitamura
Institute of Space and Astronautical Science, Sagamihara, Kanagawa, 229-8510, Japan
Ryouhei Kawabe
Nobeyama Radio Observatory, Minamisaku, Nagano 384-1305, Japan


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We made observations of H2O masers in the LkHα 234 star forming region using the Japanese domestic VLBI network (J-Net). We first present spatial and velocity structures of the maser sources of C1 and C3 which are detected by Tofani et al.(1995). The distribution of H2O maser components in C1 shows an extent of 300×150 AU. On the other hand, it shows a compact and linear extent of 15×3 AU in C3, and its position angle (RA.=232 °) roughly agrees with that of the H2 jet (PA.=226 °). Moreover, the most blue-shifted and red-shifted maser components are located at both ends of the linear extent, indicating that this might be a very small jet ejected from the deeply embedded protostar. However, it is difficult to explain the distribution of intermediate velocity components by a simple jet model. We will discuss whether the H2O masers originate in a jet or a disk.

Part 1. Star Formation
Copyright © Astronomical Society of the Pacific 2002 


Cabrit, S. et al. 1997, A&A, 321, 521 Google Scholar
Edwards, S., & Snell, R. L. 1983, ApJ, 270, 605 Google Scholar
Feibig, D. et al. 1996, A&A, 310, 199 Google Scholar
Fuente, A. et al. 2001, A&A, 366, 873 Google Scholar
Furuya, R. S. et al. 2000, ApJ, 542, L135 Google Scholar
Imai, H., Iwata, T., & Miyoshi, M. 1999, PASJ, 51, 473 CrossRefGoogle Scholar
Migenes, V. et al. 1999, ApJS, 123, 487 CrossRefGoogle Scholar
Mitchell, G. F., & Matthews, H. E. 1994, ApJ, 423, L55 Google Scholar
Patel, N. A. et al. 2000, ApJ, 538, 268 Google Scholar
Ray, T. P. et al. 1990, ApJ, 357, L45 CrossRefGoogle Scholar
Rodrigeuz, L. F. et al. 1987, A&A, 186, 319 Google Scholar
Slysh, V. I. et al. 1999, ApJ, 526, 236 Google Scholar
Tofani, G. et al. 1995, A&AS, 112, 299 Google Scholar
Torrelles, J. M. et al. 1998, ApJ, 505, 756 Google Scholar