Evidence for a Solar System-Size Accretion Disk Around the Massive Protostar G192.16-3.82
D. S. Shepherd,1*
M. J. Claussen,1
S.
E. Kurtz2
Seven-millimeter continuum observations of a
massive bipolar outflow source, G192.16-3.82, were made at a
milli-arc-second resolution with a capability that links the National
Radio Astronomy Observatory's Very Large Array radio interferometer
with the Very Long Baseline Array antenna, located in Pie Town, New
Mexico. The observations provide evidence for a true accretion disk
that is about the size of our solar system and located around a massive star. A model of the radio emission suggests the presence of a binary
protostellar system. The primary protostar, G192 S1, at the center of
the outflow, with a protostar mass of about 8 to 10 times the
solar mass, is surrounded by an accretion disk with a diameter of 130 astronomical units (AU). The mass of the disk is on the order of the
protostar mass. The outflow is poorly collimated with a full opening
angle of about 40 degrees; there is no indication of a more highly
collimated jetlike component. The companion source, G192 S2, is located
80 AU north of the primary source.
1 National Radio Astronomy Observatory, Post
Office Box 0, Socorro, NM 87801, USA.
2 Instituto de
Astronomía, Universidad Nacional Autónoma de
México, Apartado Postal 70-264, C.P. 04510 México D.F.,
México.
*
To whom correspondence should be addressed. E-mail:
dshepher{at}aoc.nrao.edu
