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Multi-transition VLBA observations of circumstellar SiO masers

R. Soria-Ruiz·F. Colomer·J. Alcolea·J. F. Desmurs·V. Bujarrabal·K. B. Marvel·P. J. Diamond·D. Boboltz
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Abstract

On this paper, we present simultaneous VLBA observations of the J=1-0 and J=2-1 rotational lines in the v=1 and v=2 vibrationally excited states of SiO (at 7 and 3 mm wavelengths). We have mapped these four maser lines in the circumstellar envelopes of three AGB stars: IRC +10011, Chi Cyg and TX Cam. We study the relative spatial distribution between these maser lines. In particular, for the two v=1 transitions, we found that the J=1-0 and J=2-1 maser spot distributions are unalike, challenging all the current theoretical pumping mechanisms for SiO masers (which predict quite similar distribution for maser lines in the same vibrational excited state).

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R. Soria-Ruiz, F. Colomer, J. Alcolea, J. F. Desmurs, V. Bujarrabal, K. B. Marvel, P. J. Diamond, D. Boboltz. 2004-01-29. Multi-transition VLBA observations of circumstellar SiO masers. https://arxiv.org/abs/astro-ph/0401616

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