2004年8月17日
Interferometric Observation of the Highly Polarized SiO Maser Emission from the $v=1, J=5-4$ Transition Associated with VY Canis Majoris
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- DOI
- 10.1086/425133
We used the Submillimeter Array to image the SiO maser emission in the $v=1$,
\$J=5-4$ transition associated with the peculiar red supergiant VY Canis
Majoris. We identified seven maser components and measured their relative
positions and linear polarization properties. Five of the maser components are
coincident to within about 150 mas ($\sim$ 200 AU at the distance of 1.5 kpc);
most of them may originate in the circumstellar envelope at a radius of about
50 mas from the star along with the SiO masers in the lowest rotational
transitions. Our measurements show that two of the maser components may be
offset from the inner stellar envelope (at the 3$\sigma$ level of significance)
and may be part of a larger bipolar outflow associated with VY CMa identified
by Shinnaga et al. The strongest maser feature at a velocity of 35.9 kms$^{-1}$
has a 60 percent linear polarization, and its polarization direction is aligned
with the bipolar axis. Such a high degree of polarization suggests that maser
inversion is due to radiative pumping. Five of the other maser features have
significant linear polarization.
\$J=5-4$ transition associated with the peculiar red supergiant VY Canis
Majoris. We identified seven maser components and measured their relative
positions and linear polarization properties. Five of the maser components are
coincident to within about 150 mas ($\sim$ 200 AU at the distance of 1.5 kpc);
most of them may originate in the circumstellar envelope at a radius of about
50 mas from the star along with the SiO masers in the lowest rotational
transitions. Our measurements show that two of the maser components may be
offset from the inner stellar envelope (at the 3$\sigma$ level of significance)
and may be part of a larger bipolar outflow associated with VY CMa identified
by Shinnaga et al. The strongest maser feature at a velocity of 35.9 kms$^{-1}$
has a 60 percent linear polarization, and its polarization direction is aligned
with the bipolar axis. Such a high degree of polarization suggests that maser
inversion is due to radiative pumping. Five of the other maser features have
significant linear polarization.
- リンク情報
- ID情報
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- DOI : 10.1086/425133
- arXiv ID : astro-ph/0408298