Winds of Very Low Metallicity OB Stars: Beyond the Magellanic Clouds

Garcia, M.; Najarro, F.; Herrero, A.; Urbaneja, M. A.; Lennon, D. J.; Castro, N.
Bibliographical reference

Massive Stars: From α to Ω, held 10-14 June 2013 in Rhodes, Greece; Online at http://a2omega-conference.net, id.66

Advertised on:
6
2013
Number of authors
6
IAC number of authors
1
Citations
0
Refereed citations
0
Description
Very low metallicity massive stars are a key piece to understanding the infant, extremely metal-poor Universe and its early development. Our models for these objects rely to a great extent on the theory of radiation driven winds, important agents of stellar evolution and feedback. However, the theory of radiation driven winds has only been thoroughly tested down to SMC metallicities and recent results on farther galaxies are alarming: the winds of more metal-poor massive stars may be stronger than predicted by the theory. We present HST-COS spectra of a sample of stars in IC1613, an irregular galaxy of the Local Group with Z ≲0.1 Z_{⊙}. This is the first UV spectral collection of resolved OB stars with poorer metal-content than the SMC, enabled by COS enhanced sensitivity. We also present wind parameters derived consistently from joint analysis of the 1150-1800 Å range together with optical spectra. The results will test the current paradigm at unexplored low metallicities and increase our knowledge of massive stars under conditions closer to those of the deep Universe.