One of the most persistent problem in solar physics is the identification of the mechanism that heats the solar corona and accelerates the fast solar wind. Magneto-hydrodynamic (MHD)waves play a crucial role in heating of ...

The work in this thesis involves detailed multi-frequency radio continuum (from 325 MHz to 15 GHz) and Hi spectroscopic studies of a few represent tative nearby galaxies which are experiencing gas-loss from their disks ...

The discovery of several bright supernovae (SNe) in recent years has evoked a great deal of interest in these objects. The study of these objects are of importance not only as probes to the end stages of stellar evolution, ...

It is evident that the origin of EGRB is not well established. In this thesis I examine the unresolved discrete origin of EGRB. The contribution from normal galaxies, starburst galaxies and AGNs to the EGRB is examined. ...

Ever since the first observations of diffuse ultraviolet radiation by Hayakawa et al. (1969) and Lillie & Witt (1976), there has been an effort to understand its distribution and its origin. Unfortunately, because of the ...

A rich variety of discs are found orbiting massive bodies in the universe. These could be accretion discs composed of gas around stellar mass compact objects fueling micro-quasar activity; protoplanetary discs, mainly ...

This thesis contributes to the field of dark energy and observational cosmology. We have investigated possible direction dependent systematic signal and non-Gaussian features in the supernovae (SNe) Type Ia data. To detect ...

The detailed nature of radio emission processes of pulsars and the exact location and distribution of the pulse emitting regions are still shrouded with mystery. Pulsars with drifting subpulses are considered as an important ...