Abstract Details

Name: Harish Kumar
Affiliation: G.D Goenka University gurugram
Conference ID: ASI2021_136
Title : Effect of Accretion on White Dwarf of Different Abundance of Carbon and Oxygen
Authors and Co-Authors : Harish Kumar(G D Goenka University, Gurugram, India), Abhinav Gupta(G D Goenka University, Gurugram, India), Shashikant Gupta(G D Goenka University, Gurugram, India)
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : Context: Type Ia Supernovae (SNe Ia) are among the most important cosmological probes. SN Ia explosion takes place when a Carbon-Oxygen (CO) White Dwarf (WD) accretes matter from its companion and its mass approaches 1.4 M_{☉}. The explosion mechanism has not been fully understood and computer simulations are required to gain further understanding. Problem: We wish to study the effect of Helium accretion on the WD properties such as its size, surface gravity and the onset of He ignition; and, the effect of variation in Carbon-Oxygen abundance on these properties. Method:The stellar evolution code ”Modules for Experiments in Stellar Astrophysics” (MESA) has been used to perform numerical simulations to study various properties of CO-WD during the accretion. In this study WD with different abundances of carbon and oxygen were subject to accretion of Helium at a slow rate 5×10^(−10) M_{⊙}. The initial mass of the WD was 0.6 M_{☉} with different abundances by mass fraction. Results: Variation of surface gravity (g) has been calculated and plotted as the accretion progresses. As expected the size of WD decreases and g increases, however, towards the end of the run g drops sharply due to helium ignition. The temperature profile and luminosity have been calculated which also indicate a sudden expansion of WD due to helium ignition. It is also observed that accretion phase lasts longer in the WD with higher abundance of Carbon before the onset of helium ignition.