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New Gamma Cas-like objects: X-ray and optical observations of SAO49725 and HD161103

Raimundo Lopes de Oliveira·Christian Motch·Frank Haberl·Ignacio Negueruela·Eduardo Janot-Pacheco
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Abstract

A growing number of early Be stars exhibit unusually hard X-ray spectra and luminosities intermediate between those typical of early type stars and those emitted by most Be/X-ray binaries in quiescence. We report on XMM-Newton and optical observations of two such Be stars, SAO 49725 and HD 161103. The nature of the hard-thermal X-ray emission is discussed in the light of the models proposed for Gamma Cas, magnetic disc-star interaction or accretion onto a compact companion object - neutron star or white dwarf. These two new objects added to similar cases discovered in XMM-Newton surveys point at the emergence of a new class of Gamma Cas analogs.

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Raimundo Lopes de Oliveira, Christian Motch, Frank Haberl, Ignacio Negueruela, Eduardo Janot-Pacheco. 2006-03-03. New Gamma Cas-like objects: X-ray and optical observations of SAO49725 and HD161103. https://doi.org/10.1051/0004-6361%3A20054589

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