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The atmospheric structure and fundamental parameters of Red Supergiants

Published online by Cambridge University Press:  23 May 2013

B. Arroyo-Torres ,
M. Wittkowski ,
J.M. Marcaide  and
P.H. Hauschildt
B. Arroyo-Torres
Affiliation:
Dpt. Astronomia i Astrofísica, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, Spain
M. Wittkowski
Affiliation:
ESO, Karl-Schwarzschild-St. 2, 85748 Garching bei München, Germany
J.M. Marcaide
Affiliation:
Dpt. Astronomia i Astrofísica, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, Spain
P.H. Hauschildt
Affiliation:
Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany
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Abstract

We present studies of the atmospheric structure and fundamental properties of the red supergiants (RSGs) VY CMa, AH Sco, UY Sct, and KW Sgr based on near-infrared K-band interferometry obtained with the VLTI/AMBER instrument with a spectral resolution of 1500. In our visibility data, we observe the presence of molecular layers of water and CO in extended atmospheres. For a uniform disk modeling, we observe size increases in the water band centered at 1.9 μm and in the CO band at 2.3–2.5 μm, with respect to the near-continuum bandpass (2.20–2.25 μm). With our spectral resolution, we obtain diameters in the near-continuum, that are free from contamination by molecular layers. Using PHOENIX atmosphere models, we estimate Rosseland-mean photospheric angular diameters of VY CMa, AH Sco, UY Sct, and KW Sgr of 11.13 ± 0.3mas, 5.81 ± 0.15mas, 5.48 ± 0.10mas, and 3.91 ± 0.25mas, respectively. We estimate radii and effective temperatures, and place the stars in the HR diagram.

The PHOENIX atmosphere models predict the spectra and the continuum visibility values, but do not predict the molecular layers visibility well: The model atmosphere is too compact when compared with the observations. This may be caused by pulsation and/or convection, which are not included in the models.

Type
Research Article
Information
European Astronomical Society Publications Series , Volume 60: Betelgeuse Workshop 2012 The Physics of Red Supergiants: Recent Advances and Open Questions , 2013 , pp. 93 - 101
Copyright
© EAS, EDP Sciences 2013

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References

Arroyo-Torres, B., Wittkowski, M., Marcaide, J.M., et al., submitted to A&A
Chelli, A., Utrera, O.H., & Duvert, G., 2009, A&A, 502, 705
Chen, X., & Shen, Z.-Q., 2008, IAU Symposium, 252, 247 CrossRef
Chiavassa, A., Lacour, S., Millour, F., et al., 2010, A&A, 511, A51
Chiavassa, A., Freytag, B., Masseron, T., & Plez, B., 2011, A&A, 535, A22
Choi, Y.K., Hirota, T., Honma, M., et al., 2008, PASJ, 60, 1007
Ekström, S., Georgy, C., Eggenberger, P., et al., 2012, A&A, 537, A146
Fu, R.R., Moullet, A., Patel, N.A., et al., 2012, ApJ, 746, 42 CrossRef
Hauschildt, P.H., & Baron, E., 1999, J. Comput. Appl. Math., 109, 41 CrossRef
Hauschildt, P.H., Allard, F., Ferguson, J., Baron, E., & Alexander, D.R., 1999, ApJ, 525, 871 CrossRef
Humphreys, R.M., & McElroy, D.B., 1984, ApJ, 284, 565 CrossRef
Ireland, M.J., Scholz, M., & Wood, P.R., 2004, MNRAS, 352, 318 CrossRef
Ireland, M.J., Scholz, M., & Wood, P.R., 2008, MNRAS, 391, 1994 CrossRef
Ireland, M.J., Scholz, M., & Wood, P.R., 2011, MNRAS, 418, 114 CrossRef
Jeong, K.S., Winters, J.M., Le Bertre, T., & Sedlmayr, E., 2003, A&A, 407, 191 PubMed
Kervella, P., Verhoelst, T., Ridgway, S.T., et al., 2009, A&A, 504, 115
Kervella, P., Perrin, G., Chiavassa, A., et al., 2011, A&A, 531, A117
Lafrasse, S., Mella, G., Bonneau, D., et al., 2010, Proc. SPIE, 7734, 140
Lançon, A., Hauschildt, P.H., Ladjal, D., & Mouhcine, M., 2007, A&A, 468, 205
Levesque, E.M., Massey, P., Olsen, K.A.G., et al., 2005, ApJ, 628, 973 CrossRef
Levesque, E.M., Massey, P., Plez, B., & Olsen, K.A.G., 2009, AJ, 137, 4744 CrossRef
Massey, P., & Olsen, K.A.G., 2003, AJ, 126, 2867 CrossRef
Massey, P., Levesque, E.M., & Plez, B., 2006, ApJ, 646, 1203 CrossRef
Mel’Nik, A.M., & Dambis, A.K., 2009, MNRAS, 400, 518
Ohnaka, K., Hofmann, K.-H., Benisty, M., et al., 2009, A&A, 503, 183
Ohnaka, K., Weigelt, G., Millour, F., et al., 2011, A&A, 529, A163
Perrin, G., Ridgway, S.T., Coudé du Foresto, V., et al., 2004, A&A, 418, 675
Perrin, G., Ridgway, S.T., Verhoelst, T., et al., 2005, A&A, 436, 317
Petrov, R.G., Malbet, F., Weigelt, G., et al., 2007, A&A, 464, 1
Royer, P., Decin, L., Wesson, R., et al., 2010, A&A, 518, L145
Smith, N., Hinkle, K.H., & Ryde, N., 2009, AJ, 137, 3558 CrossRef
Sylvester, R.J., Skinner, C.J., & Barlow, M.J., 1998, MNRAS, 301, 1083 CrossRef
Tatulli, E., Millour, F., Chelli, A., et al., 2007, A&A, 464, 29
van Belle, G.T., Creech-Eakman, M.J., & Hart, A., 2009, MNRAS, 394, 1925 CrossRef
van Loon, J.T., Cioni, M.-R.L., Zijlstra, A.A., & Loup, C., 2005, A&A, 438, 273
Wittkowski, M., Boboltz, D.A., Ireland, M., et al., 2011, A&A, 532, L7
Wittkowski, M., Hauschildt, P.H., Arroyo-Torres, B., & Marcaide, J.M., 2012, A&A, 540, L12