Title: Red supergiants in the LMC. IV. Calibration of intrinsic colours and the HRD
Abstract: Astronomische NachrichtenVolume 320, Issue 6 p. 385-396 Original Paper Red supergiants in the LMC. IV. Calibration of intrinsic colours and the HRD M.O. Oestreicher, [email protected] Centro de Investigaciones de Astronomia, Apartado Postal 264, Merida 5101-A, VenezuelaSearch for more papers by this authorTh. Schmidt-Kaler, Georg Büchner Str.37, D-97276 Margetshöchheim, GermanySearch for more papers by this author M.O. Oestreicher, [email protected] Centro de Investigaciones de Astronomia, Apartado Postal 264, Merida 5101-A, VenezuelaSearch for more papers by this authorTh. Schmidt-Kaler, Georg Büchner Str.37, D-97276 Margetshöchheim, GermanySearch for more papers by this author First published: 05 April 2001 https://doi.org/10.1002/1521-3994(199912)320:6<385::AID-ASNA385>3.0.CO;2-FCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract A new calibration of the (B — V)0, (V — R)0 and (V — I)0 colours in the Kron-Cousins system for F to M supergiants and of the (V — K)0 colours in the SAAO system of K to M supergiants in the LMC as measures of effective temperature and bolometric correction is given. For F to G supergiants the theoretical Teff-intrinsic colour-relations given by Lejeune et al. (1997) on the basis of their own model atmospheres agree mostly well with our observations. For K to M supergiants, however, their intrinsic colours are too red in most cases. The relations given by Bessell et al. (1998) based on the model atmospheres of Plez (1997) fit the observations better, but their synthetic colours are often also too red. The calibration of the bolometric correction is not reproduced well by any of the models. The HRD of the stars shows two distinct groups, one with log Teff above 3.80 and one with log Teff between 3.53 and 3.62. The upper luminosity and therefore the mass limit depends significantly on effective temperature. The F to G stars have Mbol up to -9.8 mag (corresponding to 45 M⊙), while the K to M stars do not exceed -9.0 mag (corresponding to 31 M⊙). Neither the Geneva nor the Padova models can fit the positions of the most luminous and the coolest supergiants. The discrepancy between theory and observation increases both with increasing mass loss rate and overshooting. Best agreement with the observations is reached by assuming mass loss rates of 2/3 of the de Jager et al. (1988) mass loss rates. As shown both by the luminosity and initial mass function, very luminous (i.e. massive) stars are overproportionally rare. With -3.73 ± 0.20 the slope of the initial mass function is very steep in the considered range of 16-35 M⊙, but confirms the results obtained by Massey et al. (1995) from an extensive study of the field OB stars both in the Magellanic Clouds and the Galaxy. Citing Literature Volume320, Issue6December 1999Pages 385-396 RelatedInformation
Publication Year: 1999
Publication Date: 1999-12-01
Language: en
Type: article
Indexed In: ['crossref']
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