Speckle Imaging of Gamma2 Velorum: The Inner Wind Possibly Resolved
| Autor: | Shara, Michael M., Howell, Steve B., Furlan, Elise, Garland, James T., Moffat, Anthony F. J., Zurek, David |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Accurately quantifying the rates dM/dt at which massive stars lose mass is essential to any understanding of their evolution. All dM/dt estimates to date assume wind clumping factors; not allowing for clumping leads to overestimates of dM/dt and underestimates of lifetimes and masses when these stars explode as supernovae. Mid-IR spectroscopy suggested that the wind of the nearest Wolf-Rayet star, Gamma2 Vel, is resolved with a Full Width at 10 per cent intensity of 0.5 arcsec, or 171 AU at the 342 pc distance of the star. As the Zorro speckle imager on Gemini-South is capable of 0.02 arcsec resolution, we have used it to image Gamma2 Vel at two orbital phases (0.30 and 0.44) with two narrowband and two intermediate-band filters in an attempt to resolve its wind. Our observations demonstrate that the wind of Gamma2 Vel may be resolved as a 0.07 arcsec westward elongation through an 832 nm filter at orbital phase 0.3 . If confirmed, this is the smallest scale (24 AU) at which a WR star wind asymmetry has been directly imaged. Similar imaging at multiple phases is needed to determine if the asymmetry is due to stochastic wind clumping, co-rotating interaction regions or colliding-wind, cone-shaped shocks. Comment: 7 pages, 4 Figures, in press in MNRAS |
| Databáze: | arXiv |
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