The circumstellar CO emission of RV Bootis. Evidence for a Keplerian disk?

Autor(en)
P. Bergman, Franz Kerschbaum, Hans Olofsson
Abstrakt

We report on high-resolution CO J=1-0 and J=2-1 interferometric observations of the oxygen-rich semiregular variable RV Boo supplemented by single-dish multi-transition data of CO(J=1-0, 2-1, 3-2, 4-3). Detections of the thermal SiO(v=0, J=2-1, 3-2) transitions as well as the vibrationally excited SiO(v=1, J=2-1) line are also reported. The interferometric CO J=2-1 observations, with a spatial resolution of about 1farcs 7, reveal a disk-like structure of size 4farcs 2x 3farcs 3 around RV Boo. Furthermore, the position-velocity information along a line through the center of the source at a position angle of about 150degr can be interpreted as a sign of Keplerian rotation. Six symmetrically placed features, possibly corresponding to three rings, around a central feature are seen. These observations may therefore, to our knowledge, present the first indications of a rotating disk around an AGB star. However, it cannot be fully excluded that the observed kinematical structure is caused by a bipolar outflow. From the single-dish CO observations we estimate the molecular mass of the source to be 3 x 10-5 Msun.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
Chalmers University of Technology, Stockholm Observatory
Journal
Astronomy & Astrophysics
Band
353
Seiten
257 - 263
Anzahl der Seiten
7
ISSN
0004-6361
Publikationsdatum
01-2000
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie, 103004 Astrophysik
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/a6a2a79b-d420-4581-bb43-2f78c4fc3c73