Abstract Details
| Name: Mahathi Chavali Affiliation: Manipal Institute of Technology Conference ID: ASI2017_1217 Title : Comparative analysis of X-ray emission from T Tauri stars and Herbig Ae/Be stars Authors and Co-Authors : Manoj Puravankara (TIFR) Blesson Mathew (TIFR) Sudip Bhattacharya (TIFR) Abstract Type : Oral Abstract Category : Stars,ISM and the Galaxy Abstract : Herbig Ae/Be (HAeBe) stars are thought of as evolutionary progenitors of intermediate mass main sequence stars. HAeBe stars are expected to be X-ray dark as they are fully radiative and hence incapable of driving a dynamo and are not known to possess high speed stellar winds. To address this question we investigated X-ray emission properties of HAeBe stars. We carried out a comprehensive search of the Chandra X-ray observatory archive and point source catalogue using a master list of 170 HAeBe stars in the galaxy, and found 25 HAeBe stars which show X-ray emission. Using the spectral types and distances compiled from the literature, we estimated stellar parameters such as bolometric luminosity, effective temperature, stellar radius and rotation period for these sources. We also determined the accretion disk/activity indicators such as near-infrared excess and Hα emission strength. We searched for correlations between observed X-ray properties and stellar properties and accretion/disk tracers to study the origin of X-ray emission in HAeBe stars. We further compared the X-ray properties of HAeBe stars with those displayed by their lower mass counterparts, T Tauri stars. The X-ray observations of T Tauri stars were taken from the COUP (Chandra Orion Ultradeep Project) data and the stellar and accretion/disk indicators were compiled from various catalogues. Our results show that the fractional X-ray luminosities of HAeBe stars are 2-3 orders of magnitude lower than that observed for T Tauri stars. We also find that the X-ray properties of both T Tauri stars and HAeBe stars are not correlated with accretion/disk indicators, indicating that the X-ray emission from young stars does not have circumstellar origin. We will present our results and discuss the possibility of stellar origin of X-rays in pre-main sequence stars. |