4 papers
NICER Perspective on TeV Blazar Mrk~421: X-ray Variability and Particle Acceleration
Sangeetha Kizhakkekalam, Gopal Bhatta, Navaneeth P K +1
Mrk~421 is one of the most fascinating blazars, widely studied across the electromagnetic spectrum using observations at various wavebands, from radio to the TeV gamma ray bands. W…
State-Dependent X-ray Variability in Cygnus X-1: A 12-Year NuSTAR Timing Study of Accretion Flow Geometry
Kshitij Duraphe, Kartik Mandar, Chooda Khanal +6
We present a comprehensive timing analysis of the black hole X-ray binary Cygnus X-1 using 26 NuSTAR observations spanning 2012-2024, providing the most detailed characterization t…
Transitional Spectral Behavior in Blazar OJ 287: A Comprehensive Multi-Epoch SED Study
Navaneeth P K, Gopal Bhatta, Sangeetha Kizhakkekalam
We present a comprehensive multi-wavelength investigation of BL Lac object OJ 287 using Swift and Fermi observatories spanning 2008-2025. The source exhibits significant flux varia…
Deterministic and Stochastic Study of the X-ray Emission from the TeV Blazar Mrk~421
Radim Pánis, Gopal Bhatta, Tek P. Adhikari +6
We present a comprehensive timing analysis of X-ray data from the {\it XMM-Newton} satellite, examining 50 light curves covering 17 years of observations of the blazar Mrk~421. Thi…