TITLE:
Disk-Outflow Models as Applied to High Mass Star Forming Regions through Methanol and Water Maser Observations
AUTHORS:
Hontas F. Farmer
KEYWORDS:
Masers, Methanol, Massive Star Formation, Stars: Evolution, Stars: Distances
JOURNAL NAME:
International Journal of Astronomy and Astrophysics,
Vol.4 No.4,
November
18,
2014
ABSTRACT: As the recent publication
by Breen et al. (2013)
found, Class II methanol masers are exclusively associated with high mass star
forming regions. Based on the positions of the Class I and II methanol and H2O
masers, UC H II regions and 4.5 μm infrared sources, and the center velocities
(vLSR) of the Class I methanol and H2O masers,
compared to the vLSR of the Class II methanol masers, we
propose three disk-outflow models that may be traced by methanol masers. In all
three models, we have located the Class II methanol maser near the protostar,
and the Class I methanol maser in the outflow, as is known from observations
during the last twenty years. In our first model, the H2O masers
trace the linear extent of the outflow. In our second model, the H2O
masers are located in a circumstellar disk. In our third model, the H2O
masers are located in one or more outflows near the terminating shock where the
outflow impacts the ambient interstellar medium. Together, these models reiterate the utility of
coordinated high angular resolution observations of high mass star forming regions in maser lines
and associated star formation tracers.