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SiO masers in red giants

Published online by Cambridge University Press:  03 August 2017

E. M. L. Humphreys*
Affiliation:
Onsala Space Observatory, S-439 92 Onsala, Sweden

Abstract

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In recent years, it has become possible to trace rapid structural changes occurring in the extended atmospheres of red giant stars through VLBI monitoring of SiO masers. The observations reveal a complex picture. Firstly, material is predominantly outflowing, but also infalls towards the star, in a pulsating inner envelope periodically disrupted by shocks. Secondly, circular polarization measurements may indicate that the inner circumstellar envelope is permeated by a magnetic field strong enough to be of dynamical importance. Finally, towards a few stars, observations also show evidence for rotation of the SiO maser region. Current SiO maser models can reproduce many of the key features of circumstellar SiO maser emission, and have successfully predicted e.g. the infall of SiO masing gas and the observed spatial separation of v = 1 and v = 2 43 GHz masers. However, both stellar hydrodynamical and maser codes need to increase in complexity in order to model fully these regions. In this review I will discuss the current developments in circumstellar SiO maser observations and models.

Type
Part 2. Stellar Masers
Copyright
Copyright © Astronomical Society of the Pacific 2002 

References

Alcolea, J., & Bujarrabal, V. 1992, A&A, 257, 701 Google Scholar
Alcolea, J., Bujarrabal, V., & Gomez-Gonzalez, J. 1990, A&A, 231, 431 Google Scholar
Alcolea, J., Pardo, J.R., Bujarrabal, V., et al. 1999, A&AS 139, 461 Google Scholar
Barvainis, R., McIntosh, G., & Predmore, C. R. 1987, Nature, 329, 613 Google Scholar
Bieging, J.H., Shaked, S., & Gensheimer, P. D. 2000, ApJ, 543, 897 Google Scholar
Boboltz, D., Diamond, P.J., & Kemball, A.J. 1997, ApJ, 487, L147 Google Scholar
Boboltz, D.A., & Diamond, P.J. 2000, AAS, 197, 4507 Google Scholar
Boboltz, D.A., & Marvel, K.B. 2000, ApJ, 545, L149 Google Scholar
Bowen, G. 1988, ApJ, 329, 299 Google Scholar
Bujarrabal, V. 1994a, A&A, 285, 953 Google Scholar
Bujarrabal, V. 1994b, A&A, 285, 971 Google Scholar
Bujarrabal, V., Planesas, P., & del Romero, A. 1987, A&A, 175, 164 Google Scholar
Cernicharo, J., & Bujarrabal, V. 1992, ApJ, 401, L109 Google Scholar
Cernicharo, J., Bujarrabal, V., & Santaren, J. L. 1993, ApJ, 407, L33 Google Scholar
Cho, S.-H., Chung, H.-S., Kim, H.-R., et al. 1998, ApJS, 115, 277 Google Scholar
Cho, S.-H., Kaifu, N., & Ukita, N. 1996a, AJ, 111, 1987 Google Scholar
Cho, S.-H., Kaifu, N., & Ukita, N. 1996b, A&AS, 115, 117 Google Scholar
Clark, F. O., Troland, T. H., & Miller, J. S. 1985, ApJ, 289, 756 Google Scholar
Colomer, F., Graham, D. A., Krichbaum, T. P., et al. 1992, A&A, 254, L17 Google Scholar
Cuntz, M., & Muchmore, D.O. 1994, ApJ, 433, 303 Google Scholar
Deguchi, S. Nakashima, J.I., & Balasubramanyam, R., 2001, PASJ, 53, 305 Google Scholar
Desmurs, J.F., Bujarrabal, V., Colomer, F., & Alcolea, J. 2000, A&A, 360, 189 Google Scholar
Diamond, P. J., & Kemball, A. J. 1999, in IAU 191, 195 Google Scholar
Diamond, P.J., Kemball, A.J, Junor, W., et al. 1994, ApJ, 430, L61 Google Scholar
Doel, R.C., Gray, M.D., Humphreys, E.M.L., et al. 1995, A&A 302, 797 Google Scholar
Doeleman, S.S., Lonsdale, C.J., & Greenhill, L.J. 1998, ApJ, 494, 400 Google Scholar
Elitzur, M. 1996, ApJ, 457, 415 Google Scholar
Fourre, R., Jewell, P. R., & Glenn, J. 2000, AAS, 197, 4404 Google Scholar
Gardner, J.M., Phillips, R.B., & Boboltz, D. A. 2000, AAS, 197, 4506 Google Scholar
Gonzalez-Alfonso, E., Alcolea, J., & Cernicharo, J. 1996, A&A, 313, L13 Google Scholar
Gonzalez-Alfonso, E., & Cernicharo, J. 1997, A&A, 322, 938 Google Scholar
Gray, M.D. & Humphreys, E.M.L. 2000, New Ast., 5, 155 Google Scholar
Gray, M. D., Humphreys, E. M. L., & Yates, J. A. 1999, MNRAS, 304, 906 Google Scholar
Gray, M. D., Ivison, R. J., Humphreys, E. M. L., et al. 1998, MNRAS, 295, 970 Google Scholar
Greenhill, L.J., Colomer, F., Moran, J.M., et al. 1995, ApJ, 449, 365 Google Scholar
Habing, H. J. 1996, A&AR, 7, 97 Google Scholar
Hall, P.J., Allen, D.A., Troup, E.R., et al. 1990, MNRAS, 243, 480 Google Scholar
Hartquist, T.W., & Dyson, J.E. 1997, A&A, 319, 589 Google Scholar
Herpin, F., & Baudry, A. 2000, A&A, 359, 1117 Google Scholar
Herpin, F., Baudry, A., Alcolea, J., Cernicharo, J. 1998, A&A, 334, 1037 Google Scholar
Heske, A., 1989, A&A, 208, 77 Google Scholar
Hinkle, K.H., Lebzelter, T., & Scharlach, W.W.G., 1997, AJ, 114, 2686 Google Scholar
Hollis, J. M., Pedelty, J. A., Forster, J. R., et al. 2000, ApJ, 543, L81 Google Scholar
Humphreys, E.M.L., Gray, M.D., Yates, J.A., et al. 1996, MNRAS, 282, 1359 Google Scholar
Humphreys, E.M.L., Gray, M.D., Yates, J.A., et al. 1997, MNRAS, 287, 663 CrossRefGoogle Scholar
Jimeno, P., Gray, M.D., & Balint-Kurti, G.G. 1999, JChemPhys, 111, 4966 Google Scholar
Kemball, A.J., & Diamond, P. J. 1997, ApJ, 481, L111 Google Scholar
Kwan, J., & Scoville, N. 1974, 1974, ApJ, 194, L97 Google Scholar
Lockett, P., & Elitzur, M. 1992, ApJ, 399, 704 Google Scholar
McIntosh, A. C., & Predmore, C. R. 1991, in ASP Conference Series, 16, 83 Google Scholar
McIntosh, A. C., & Predmore, C. R. 1993, ApJ, 404, L71 Google Scholar
Miyoshi, M., Matsumoto, K., Kameno, S., et al. 1994, Nature, 371, 395 Google Scholar
Nyman, L.-A., Hall, P.J., & Le Bertre, T. 1993, A&A, 280, 551 Google Scholar
Nyman, L.-A. Hall, P. J., & Olofsson, H. 1998, A&AS, 127, 185 Google Scholar
Nyman, L.-A., & Olofsson, H. 1986, A&A, 158, 67 Google Scholar
Pardo, J. R., Cernicharo, J., Gonzalez-Alfonso, E., et al. 1998, A&A, 329, 219 Google Scholar
Pijpers, F.P., Pardo, J.R., & Bujarrabal, V. 1994, A&A, 286, 501 Google Scholar
Reid, M.J., & Menten, K.M., 1997, ApJ, 476, 327 Google Scholar
Western, L. R., & Watson, W. D. 1983, ApJ, 275, 195 Google Scholar
Wiebe, D. S., & Watson, W. D. 1998, ApJ, 503, L71 CrossRefGoogle Scholar