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Maser Effects in Recombination Lines: the case of Eta Carinae

Published online by Cambridge University Press:  16 July 2018

Zulema Abraham ,
Pedro P. B. Beaklini  and
Diego Falceta-Gonçalves
Zulema Abraham
Affiliation:
Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Rua do Matão 1226, 05508-090, São Paulo, SP, Brazil. email: [email protected]
Pedro P. B. Beaklini
Affiliation:
Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Rua do Matão 1226, 05508-090, São Paulo, SP, Brazil. email: [email protected]
Diego Falceta-Gonçalves
Affiliation:
Escola de Artes, Ciências e Humanidades, Universidade de Saõ Paulo, R. Arlindo Bettio 1000, 03828-000, São Paulo, SP, Brazil
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Abstract

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Population of high quantum number states can differ from their LTE values at high densities (Ne ~106 − 108 cm−3) and temperatures of the order of 104 K. In this case, the intensity of recombination lines can be strongly amplified. The amount of amplification depends on density and temperature, and it is different for different quantum numbers, allowing the determination of the physical and kinematic conditions of the emitting region through the observation of recombination lines of different quantum numbers. This was the case of the massive binary system η Carinae. This system was observed with ALMA in the recombination lines H21α, H28α, H30α, H40α and H42α and the continuum at the frequencies of the corresponding lines. The continuum spectrum was characteristic of a compact HII region, becoming optically thin at around 300 GHz. From the intensity and width of the recombination lines we concluded that the not-resolved emission region, assumed spherically symmetric, is a shell of 40 AU radius and 4 AU width, expanding at velocities between 20 and 60 km s−1, with density of 107 cm−3 and temperature of 17000 K.

Keywords

masersmass lossstellar windsη Carinae
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 13 , Symposium S336: Astrophysical Masers: Unlocking the Mysteries of the Universe , September 2017 , pp. 271 - 274
Copyright
Copyright © International Astronomical Union 2018 

References

Abraham, Z., Damineli, A., Durouchoux, P., in Cosmic MASERS, from Protostars to Black Holes, 2002, IAU Symposium 206, 234, ed. Migenes, V. & Reid, M. J.Google Scholar
Abraham, Z., Falceta-Gonçalves, D., Dominici, T. M., et al. 2005, A&A, 437, 997Google Scholar
Abraham, Z., Falceta-Gon calves, D., & Beaklini, P. P. B., 2014, ApJ, 791, 95Google Scholar
Corcoran, M. F., Ishibashi. K., Swank, J. H., & Petre, R., 2001, ApJ, 547, 1034CrossRefGoogle Scholar
Cox, P. G., Martin-Pintado, J., Bachiller, R., et al. 1995a, A&A, 295, L39Google Scholar
Cox, P. G., Mezger, P. G., Sievers, A., et al. 1995b, A&A, 297, 168Google Scholar
Damineli, A., 1996, ApJ, 460, L49CrossRefGoogle Scholar
Duncan, R. A., White, S. M., & Lim, J., 1997, MNRAS, 290, 680Google Scholar
Fernández-Lajús, E., Farinã, C., Torres, A. F., et al., 2009, A&A, 493, 1093Google Scholar
Storey, P. J. & Hammer, D. G., 1995, MNRAS, 272, 41Google Scholar