Abstract Details

Name: Poonam Chandra
Affiliation: NCRA-TIFR, Pune
Conference ID: ASI2021_LNMlecture
Title : Lives of massive stars: exploring the aspects of magnetism
Authors and Co-Authors : Poonam Chandra
Abstract Type :
Abstract Category : ASI Laxminarayana & Nagalaxmi Modali Award Lecture
Abstract : Hot, massive OB stars are the energetic and chemical engines of galaxies. They seed the galaxies with heavy elements, help trigger new generations of star formation, and drive strong, high-speed stellar wind mass outflows. These stars also end their lives as one of the biggest explosions in the universe, i.e. supernovae or gamma-ray bursts, either by their gravitational collapse, or assisted by a nearby companion. Currently 10% of known massive stars are known to host kG dipolar magnetic fields, the origin of which remains contradictory. While stellar evolution models have generally accounted for mass-loss, rotation and metallicity, the aspects of magnetism are in their infancy, even though they may have important implications in their evolution and end products as magnetars and magnetic white dwarfs. The stellar wind properties of OB stars with magnetic fields are modified in important ways as compared to the winds of non-magnetic stars, introducing significant changes across the entire electromagnetic spectrum. VLAWe are carrying out systematic studies of these stars in radio bands using the uGMRT and the VLA. Our studies have shown that radio observations of magnetic massive stars probe most critical aspects of the physics of these stars. In addition, we have discovered a rare electron cyclotron maser emission (ECME) phenomenon from a subset of these massive stars. While stars with ECME have given us deep understanding via unveiling their plasma environments, 3D magnetic topology and nature of magnetic fields, several new results have thrown us by surprise.