Pilot VLBI Survey of SiO v = 3 J = 1→0 Maser Emission around Evolved Stars
Abstract
In this letter, we report on detections of SiO v = 3 J = 1→0 maser emission in very long-baseline interferometric (VLBI) observations towards 4 out of 12 long-period variable stars: WX Psc, R Leo, W Hya, and T Cep. The detections towards WX Psc and T Cep are new ones. We also present successful astrometric observations of SiO v = 2 and v = 3 J = 1→0 maser emissions associated with two stars: WX Psc and W Hya and their position-reference continuum sources: J010746.0+131205 and J135146.8-291218 with the VLBI Exploration of Radio Astrometry (VERA). The relative coordinates of the position-reference continuum source and SiO v = 3 maser spots were measured with respect to those of an SiO v = 2 maser spot adopted as a fringe-phase reference. Thus, the faint continuum sources were inversely phase-referenced to the bright maser sources. This implies possible registration of multiple SiO maser line maps onto a common coordinate system with 10 microarcsecond-level accuracy.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- December 2012
- DOI:
- 10.1093/pasj/64.6.L6
- arXiv:
- arXiv:1209.3879
- Bibcode:
- 2012PASJ...64L...6I
- Keywords:
-
- masers;
- stars: AGB and post-AGB;
- stars: individuals (WX Piscium;
- R Leonis;
- W Hydrae;
- T Cephei);
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 5 Pages, 3 figures, Fig.3 and Tab. 2 were corrected