X-ray variability of sigma Orionis young stars with ROSAT - Astrophysics > Solar and Stellar AstrophysicsReportar como inadecuado




X-ray variability of sigma Orionis young stars with ROSAT - Astrophysics > Solar and Stellar Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We used the Aladin Virtual Obsrvatory tool and High Resolution Imager ROSATarchival data to search for X-ray variability in scale of days in 23 youngstars in the sigma Orionis cluster and a background galaxy. Five starsdisplayed unambiguous flares and had probabilities p var >> 99% of being actualvariables. Two of the detected flares were violent and long-lasting, withmaximum duration of six days and amplitude of eight times above the quiescentlevel. We classified another four stars as possible X-ray variables, includingthe binary system formed by the B2Vp star sigma Ori E and its close late-typecompanion. This makes a minimum frequency of high-amplitude X-ray variabilityin excess of a day of 39% among sigma Orionis stars. The incidence of this kindof X-ray variability seems to be lower among classical T Tauri stars withmid-infrared flux excesses than among fast-rotating, disk-less young stars.



Autor: J. A. Caballero, J. Lopez-Santiago, E. de Castro, M. Cornide

Fuente: https://arxiv.org/







Documentos relacionados