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Projeto Observacional para 2016A - SO2016A-017

Autor: Raimundo Lopes de Oliveira
Instituição: UFS
e-mail: rlofilho@gmail.com

Ada Nebot
C. Motch
Myron Smith

Título: A census of hard X-ray emitters: revealing and investigating Wolf-Rayets and gamma-Cassiopeiae like stars

Resumo: We propose to carry out infrared and optical spectroscopic observations to establish the nature of a sample of hard X-ray emitting stars which were identified by our group from the 3XMM catalogue. Their infrared (2MASS and/or GLIMPSE) counterparts indicate that a significant fraction of them is comprised of Wolf-Rayet and gamma-Cas analog star candidates. The goal of the project is to significantly enlarge the number of known X-ray emitting WRs and gamma-Cas stars in order to better discriminate the dependency of their X-ray properties (luminosity, temperature, and variability) upon spectral type, mass, wind velocity, rotation, and ultimately binarity. This approach will shed new light on the X-ray emission mechanism in operation in those objects: i) magnetic channelling, accretion, or wind collision for Wolf-Rayet stars and the ii) role of subsurface convecting layers in close to critically rotating stars and the circumstellar disk in the case of gamma-Cas analogs.