A&A 475, 569-574 (2007)
DOI: 10.1051/0004-6361:20077982
Observations of V838 Monocerotis in the CO rotational transitions
T. Kaminski1, M. Miller2, and R. Tylenda11 Department for Astrophysics, N. Copernicus Astronomical Centre, Rabianska 8, 87-100 Torun, Poland
e-mail: tomkam@ncac.torun.pl
2 I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
(Received 31 May 2007 / Accepted 21 September 2007)
Abstract
Aims.We investigate the structure of a field around the position of
V838 Mon as seen in the lowest CO rotational transitions.
We also measure and analyse emission in the same lines at
the position of V838 Mon.
Methods.Observations have
primarily been done in the 12CO J = 2
1 and J = 3
2 lines using
the KOSMA telescope. A field of 3.4 squared degrees has been mapped in the
on-the-fly mode in these transitions. Longer integration spectra in the
on-off mode have been obtained to study the emission at the position of
V838 Mon.
Selected positions in the field have also been observed in
the 12CO J = 1
0 transition using the Delingha telescope.
Results.In the
observed field we have identified many molecular clouds. They can be divided
into two groups from the point of view of their observed radial velocities.
One, having
in the range 18-32 km s-1, can be
identified with the Perseus Galactic arm. The other one, having
between 44-57 km s-1, probably belongs to the
Norma-Cygnus arm. The radial velocity of V838 Mon is within the second
range but the object does not seem to be related to any of the observed
clouds. We did not find any molecular buble of a 1°
dimension around the position of V838 Mon claimed in van Loon et al.
An emission has been detected at the position of the
object in the 12CO J = 2
1 and J = 3
2 transitions. The
emission is very narrow (FWHM
1.2 km s-1)
and at
= 53.3 km s-1. Our analysis of the data suggests
that the emission is probably extended.
Key words: stars: individual: V838 Monocerotis -- radio lines: ISM -- ISM: clouds -- ISM: molecules
© ESO 2007

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