Evidence for Different Disk Mass Distributions Between Early and Late-Type Be Stars in the BeSOS Survey
Autor: | S. Kanaan, Carol E. Jones, Michel Curé, C. Arcos, T. A. A. Sigut |
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Jazyk: | angličtina |
Rok vydání: | 2017 |
Předmět: |
Physics
Angular momentum Mass distribution 010308 nuclear & particles physics Star (game theory) FOS: Physical sciences Astronomy and Astrophysics Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Type (model theory) Stellar classification 01 natural sciences Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science 0103 physical sciences Range (statistics) Astrophysics::Solar and Stellar Astrophysics Emission spectrum Astrophysics::Earth and Planetary Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics |
Popis: | The circumstellar disk density distributions for a sample of 63 Be southern stars from the BeSOS survey were found by modelling their H$\alpha$ emission line profiles. These disk densities were used to compute disk masses and disk angular momenta for the sample. Average values for the disk mass are 3.4$\times$10$^{-9}$ and 9.5$\times$10$^{-10}$ $M_{\star}$ for early (B0-B3) and late (B4-B9) spectral types, respectively. We also find that the range of disk angular momentum relative to the star are between 150-200 and 100-150 $J_{\star}/M_{\star}$, again for early and late-type Be stars respectively. The distributions of the disk mass and disk angular momentum are different between early and late-type Be stars at a 1\% level of significance. Finally, we construct the disk mass distribution for the BeSOS sample as a function of spectral type and compare it to the predictions of stellar evolutionary models with rapid rotation. The observed disk masses are typically larger than the theoretical predictions, although the observed spread in disk masses is typically large. |
Databáze: | OpenAIRE |
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