MR. PRASANTA BERA

The mass and radius of white dwarfs (WDs) follow a specific relation as WDs are electron degenerate systems. WDs can support mass up to Chandrasekhar mass limit (1.44 M_sun) against gravity due to the electron degeneracy pressure. Explosion of limiting mass WDs give rise to supernova of type Ia (SNIa), used as standard candles to calibrate the distance of galaxies. But a few recently observed SNIa (e.g. 2003fg, 2006gz, 2009dc) have been found to be more luminous than usual, indicating the involvement of super Chandrasekhar mass WDs i.e., of mass more than 1.44 M_sun. The presence of extremely strong magnetic field can increase the maximum mass limit of WDs. The structure of a WD is also modified due to the presence of Lorentz force. In this talk, the speaker will introduce the formalism to obtain self-consistent field of the axisymmetric structure and the modification of mass-radius relation due to the presence of the strong magnetic field. The effects of i) quantization of electron orbits in a strong field, ii) coulomb corrections in the ion lattice, iii) general relativistic gravity, on these structures will be discussed in the talk.