Possible formation of lowly luminous highly magnetized white dwarfs by accretion leading to SGRs/AXPs

Mukhopadhyay, B and Bhattacharya, M and Rao, AR and Mukerjee, S and Das, U (2018) Possible formation of lowly luminous highly magnetized white dwarfs by accretion leading to SGRs/AXPs. In: 15th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics, and Relativistic Field Theories, MG 2018, 1-7 July 2018, University of Rome "La Sapienza"Rome; Italy.

PDF REC_DEV_THE_EXP_GEN_REL_AST_REL_FIE_THE_2018.pdf - Published Version Restricted to Registered users only Download (173kB) | Request a copy

Abstract

We sketch a possible evolutionary scenario by which a highly magnetized super- Chandrasekhar white dwarf could be formed by accretion on to a commonly observed magnetized white dwarf. This is an exploratory study, when the physics in cataclysmic variables (CVs) is very rich and complex. Based on this, we also explore the possibility that the white dwarf pulsar AR Sco acquired its high spin and magnetic field due to repeated episodes of accretion and spin-down. We show that strong magnetic field dra- matically decreases luminosity of highly magnetized white dwarf (B-WD), letting them below the current detection limit. The repetition of this cycle can eventually lead to a B-WD, recently postulated to be the reason for over-luminous type Ia supernovae. A spinning B-WD could also be an ideal source for continuous gravitational radiation and soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs). SGRs/AXPs are generally believed to be highly magnetized, but observationally not confirmed yet, neutron stars. Invoking B-WDs does not require the magnetic field to be as high as for neutron star based model, however reproducing other observed properties intact. © Relativistic Field Theories, MG 2018. All rights reserved.

Item Type:	Conference Paper
Publication:	15th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics, and Relativistic Field Theories, MG 2018
Publisher:	World Scientific Publishing Co. Pte. Ltd.
Additional Information:	cited By 0; Conference of 15th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics, and Relativistic Field Theories, MG 2018 ; Conference Date: 1 July 2018 Through 7 July 2018; Conference Code:160314
Keywords:	white dwarfs; strong magnetic fields; CVs; pulsars; SGRs/AXPs
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	22 Oct 2020 10:44
Last Modified:	22 Oct 2020 10:44
URI:	http://eprints.iisc.ac.in/id/eprint/66210

Actions (login required)

View Item