Research Interests:
I have worked on the evolution of isolated young neutron stars within the fallback disc model during my PhD and subsequent years. I have experiences on (1) estimating emission properties of accretion discs (2) modelling the long-term evolution of fallback discs as well as the short-term X-ray enhancements observed from anomalous X-ray pulsars and (3) calculating disc torques acting on the neutron star interacting by inner disc at the boundary layer.
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My current research interests focused mainly on transitional millisecond pulsars (tMSPs), radio or X-ray MSPs those having potential to transition to each other. In this context, it is crucial to understand the condition for propeller-accretion transition.
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The so-called torque reversal phenomena have been observed from several LMXBs and HMXBs. I am interested to model theoretically this behaviour accompanied by X-ray luminosity variation as well.
I also try to understand what is the relation between pulsed fraction and X-ray luminosity of accreting neutron stars in the course of X-ray outbusts.
Fallback DISC Model
It is rather likely that part of the matter from the SN explosion could be re-collected
around the neutron star (Colgate, 1971; Chevalier, 1989). Due to the conservation of angular momentum, this fossil matter can flow into the star as a disk (Michel & Dessler, 1981).
Such a fallback disk can provide a continuous mass flow towards the star affecting both rotational and electromagnetic emission properties of the star (Chatterjee et al 2000, Alpar 2001). When there is a viscously active fallback disc around the neutron star, the disc torques are likely to dominate magnetic dipole torques while the accretion luminosity significantly exceeds the intrinsic cooling and the magnetic dipole radiation luminosity of the star.
Image credit: https://www.nasa.gov