Observational Effects of Stellar Rotation on Be Stars' Disks

FAES, DANIEL M.; CARCIOFI, ALEX C.; DE SOUZA, A. D.; GRANADA, A.

Rodas

Congreso; Massive Stars: From α to Ω 2013

National Observatory of Athens - European Space Agency

Be stars are known to be fast rotators. At high rotation rates aprofound modification of the radiation field reaching the circumstellarenvironment is expected. The origin of this modification is the decreaseof the effective gravity on stellar surface leading to the stellargeometrical flattening and the gravity darkening effect predicted by VonZeipel. Making use of the radiative transfer code HDUST we discuss theconsequences of such stellar rotation on the structure of Be star disksbased on the Viscous Decretion Disk model. Observational predictions arealso made, as SED, IR-excess and Hydrogen line profiles. The modifiedillumination of the circumstellar disk generates significant changes inthese quantities. Ascertaining these changes is useful to set some ofthe fundamental parameters of the Be system and to unveil the role ofstellar rotation over the stellar evolution.