Abstract Details

Name: Hema Anilkumar
Affiliation: CHRIST (Deemed to be University)
Conference ID: ASI2020_280
Title : Chandra X-ray Analysis of Herbig Ae/Be Stars
Authors and Co-Authors : Hema Anilkumar, Blesson Mathew, Jithesh V, Sreeja S. Kartha, Manoj Puravankara, Mayank Narang
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : Herbig Ae/Be (HAeBe) stars are intermediate-mass pre-main sequence (PMS) stars with spectral types from B0 to F5, characterized by a strong infrared excess and emission lines. It is observed that HAeBe stars emit X-rays, but the origin of this emission is unknown. In Sun-like stars, X-rays are emitted from the corona, due to the interaction of plasma with the magnetic field. This phenomenon partly explains the X-ray emission in low mass T Tauri stars, as they have a subsurface convective zone. But, intermediate-mass HAeBe stars lack the convective zone and are not expected to have magnetic field produced through alpha-omega dynamo mechanism. It is thought that an unseen binary companion is responsible for the observed X-ray emission. Alternative X-ray production mechanisms, related to stellar winds, star-disk magnetospheres have been proposed. However, a convincing and unique explanation for the X-ray emission from HAeBe stars has not been identified. We performed a systematic search for X-ray detection using a sample of 218 HAeBe stars with Chandra data archive and found X-ray flux measurements for 51 HAeBe stars, of which 29 have good quality data and are well resolved, which is used for the present study. We found 14 HAeBe stars having a companion star, with X-ray emission seen from both the stars. This sample can be used as a testbed to see whether there is any distinction between the X-ray properties of HAeBe and T Tauri stars. In this work, the global X-ray properties of HAeBe stars such as unabsorbed flux, luminosity, temperature components, variability, absorption etc., are examined aiming to study the mechanism responsible for the X-ray emission from HAeBe stars.