Research Experience and Academic Contributions

Over the past two decades, I have developed extensive research experience through collaborations with several prestigious scientific and academic institutions in India and abroad. In India, these include the Indian Centre for Space Physics (ICSP), Kolkata; Tata Institute of Fundamental Research (TIFR), Mumbai; Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram; and Physical Research Laboratory (PRL), Ahmedabad, among others. My international research engagements include the Abdus Salam International Centre for Theoretical Physics (ICTP), Italy; NASA/Goddard Space Flight Center (GSFC), USA; and National Tsing Hua University (NTHU), Taiwan.

I have successfully supervised seven Ph.D. students who completed their doctoral degrees from the University of Calcutta. In addition, I have supervised twelve M.Sc. dissertation students and one B.Sc. project student. I have also successfully completed five research projects, each of three years' duration, funded by the Department of Science and Technology (DST) and the Indian Space Research Organisation (ISRO), Government of India, as the Principal Investigator (PI).

Research Interests and Scientific Contributions
My primary research interest lies in the study of compact X-ray binaries, particularly black hole X-ray binaries (BH-XRBs), during their active and outburst phases. I investigate these systems through comprehensive spectro-temporal and polarimetric analyses of multi-wavelength and multi-mission observational data. Such studies provide important insights into the accretion and ejection mechanisms, accretion-flow geometry, and underlying flow dynamics. They also enable us to constrain fundamental intrinsic parameters of black holes, including their masses, spins, distances, and inclination angles. So far, I have been involved in the detailed investigation of more than 20 black hole X-ray binary systems.

I was involved in implementing the Two-Component Advective Flow (TCAF) model, a generalized physical solution for accretion flows, in NASA's widely used X-ray spectral analysis software package, XSPEC, as an additive table model. This implementation enables the direct extraction of fundamental accretion-flow parameters from X-ray spectral fitting, providing users with a more intuitive and physically meaningful understanding of accretion processes around black holes.

In addition to black hole astrophysics, I have worked on other high-energy transient phenomena, including gamma-ray bursts (GRBs) and solar flares, contributing to a broader understanding of energetic astrophysical processes.

Space-Based and Experimental Research Activities
I have been actively involved in several space-based and experimental research programmes. These include the Indo-Russian collaborative satellite mission CORONAS-PHOTON, launched in 2009, which carried the RT-2 payload; the X-ray detector development programme XDXL, jointly supported by ICTP and the Italian National Institute for Nuclear Physics (INFN).

More recently, I have been involved in CubeSat-related research activities at NTHU, Taiwan. These experiences have provided valuable opportunities to contribute to space-instrumentation development, detector technologies, and high-energy astrophysical observations.

Future Research Plans

Looking ahead, I aim to strengthen both observational, theoretical and experimental research activities in high-energy astrophysics. One of our major long-term goals is to develop an independent, broadband high-energy astrophysical observatory covering the energy range from soft X-rays to high-energy gamma-rays (approximately 0.2 keV–2 MeV). Such an observatory would provide broad spectral coverage for investigating compact objects and transient high-energy phenomena, particularly black hole X-ray binaries, neutron stars, gamma-ray bursts, and solar flares.
I also intend to continue developing collaborations involving space-based instrumentation, satellite missions, and advanced data-analysis techniques, while actively engaging young researchers through Ph.D. supervision and collaborative research programmes.