Astronomy and Astrophysics – Astronomy
Scientific paper
May 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003apj...588l.105p&link_type=abstract
The Astrophysical Journal, Volume 588, Issue 2, pp. L105-L108.
Astronomy and Astrophysics
Astronomy
14
Stars: Circumstellar Matter, Radio Lines: Stars, Stars: Agb And Post-Agb, Techniques: Interferometric
Scientific paper
We present simultaneous VLBI maps of the J=1-->0 (43.1 GHz) and J=2-->1 (86.2 GHz) silicon monoxide (SiO) v=1 masers in the circumstellar envelope of the asymptotic giant branch star R Cassiopeiae that have been registered to submilliarcsecond precision. Our images allow specific comparisons of maser strengths from volumes that are about 1/10 AU in projected size. Bright 86.2 GHz v=1 masers in two cases operate from the same gas volumes as the 43.1 GHz v=1 masers. The relative strengths of the 43.1 and 86.2 GHz masers vary from roughly unity to lower limits of several hundred to 1. The low strength of J=2-->1 masers relative to J=1-->0 might arise from neutral densities of H2<=4×109 cm-3 at 1.5-2 times the photospheric radius from R Cas. The SiO masers of R Cas at this epoch are not consistent with emission models that employ pulsation-driven shocks unless the phasing of such models can be shifted.
Doeleman Sheperd S.
Lonsdale Colin J.
Phillips Robert B.
Straughn A. H.
No associations
LandOfFree
R Cassiopeiae: Relative Strengths of SiO Masers at 43 and 86 GHz does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with R Cassiopeiae: Relative Strengths of SiO Masers at 43 and 86 GHz, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and R Cassiopeiae: Relative Strengths of SiO Masers at 43 and 86 GHz will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1371789