Carina OB Stars: X-ray Signatures of Wind Shocks and Magnetic Fields
| Autor: | Gagne, Marc, Fehon, Garrett, Savoy, Michael R., Cohen, David H., Townsley, Leisa K., Broos, Patrick S., Povich, Matthew S., Corcoran, Michael F., Walborn, Nolan R., Evans, Nancy Remage, Moffat, Anthony F. J., Naze, Yael, Oskinova, Lida M. |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | ApJS, 194, 5 (26p, 2011) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0067-0049/194/1/5 |
| Popis: | The Chandra Carina Complex contains 200 known O- and B type stars. The Chandra survey detected 68 of the 70 O stars and 61 of 127 known B0-B3 stars. We have assembled a publicly available optical/X-ray database to identify OB stars that depart from the canonical Lx/Lbol relation, or whose average X-ray temperatures exceed 1 keV. Among the single O stars with high kT we identify two candidate magnetically confined wind shock sources: Tr16-22, O8.5 V, and LS 1865, O8.5 V((f)). The O4 III(fc) star HD 93250 exhibits strong, hard, variable X-rays, suggesting it may be a massive binary with a period of >30 days. The visual O2 If* binary HD 93129A shows soft 0.6 keV and hard 1.9 keV emission components, suggesting embedded wind shocks close to the O2 If* Aa primary, and colliding wind shocks between Aa and Ab. Of the 11 known O-type spectroscopic binaries, the long orbital-period systems HD 93343, HD 93403 and QZ Car have higher shock temperatures than short-period systems such as HD 93205 and FO 15. Although the X-rays from most B stars may be produced in the coronae of unseen, low-mass pre-main-sequence companions, a dozen B stars with high Lx cannot be explained by a distribution of unseen companions. One of these, SS73 24 in the Treasure Chest cluster, is a new candidate Herbig Be star. Comment: To be published in a special issue of the Astrophysical Journal Supplement on the Chandra Carina Complex Project |
| Databáze: | arXiv |
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