This study aims to investigate the characteristics of X-ray sources in elliptical (E), lenticular (S0), spiral (S), and active/interacting galaxies, and analyze their relationship with star formation activity. We use X-ray data from the Chandra X-ray Observatory, combined with infrared observations from Spitzer and Herschel, to estimate the star formation rate (SFR) using the X-ray luminosity...
The ultra-compact low mass X-ray binary 4U 1820-30 exhibits a ~3% orbital modulation in its X-ray light curve with a period of 685 seconds, along with a superorbital modulation where the flux varies by a factor of 2 over a period of ~170 days. Zdziarski et al.(2007), using early RXTE data, discovered a correlation between the amplitude of the orbital modulation and the accretion rate,...
Multi-dimensional instabilities coupled with magnetic fields, such as the magnetorotational instability (MRI), are considered important contributors to the explosion mechanism of core-collapse supernovae in extreme scenarios. In this work, we present three-dimensional simulations of a 40-solar-mass progenitor using the GPU-accelerated magnetohydrodynamics code GAMER. We investigate the effects...
We use 3D special relativistic hydrodynamic (SRHD) simulations to study AGN-driven winds in a disk galaxy. Our results reveal an early-stage (t ~ 0.1 Myr) asymmetry in bubble formation, with one bubble reaching velocities up to 2000 km/s while the other remains underdeveloped due to interactions with the clumpy disk. This aligns with JWST observations of NGC 7469, which show a circumnuclear...
Chiral effects induced by quantum anomalies, such as the chiral magnetic effect, are expected to influence the dynamics of core-collapse supernovae (CCSN). These effects arise in strong magnetic fields and rapid flows, which are common in supernova cores. In this project, we investigate the potential impact of chiral neutrino radiation transport in CCSN, focusing on contributions from...
The observation of the M87* black hole shadow has opened new avenues for exploring horizon-scale phenomena around astrophysical black holes.
Current interpretations of black hole images often rely on state-of-the-art general relativistic magnetohydrodynamics (GRMHD) simulations to model ion
temperatures, combined with post-processed radiative modeling of electron radiation. However, these...
Fast Radio Bursts (FRBs) are high-energy, transient phenomena with extremely short durations, and their origin remains uncertain. Various theories have been proposed to explain their mechanism. Among these, FRB 200428 has been confirmed to originate from the magnetar SGR 1935+2154, providing a potential model for understanding other FRBs. In this study, I use the physical parameters of FRB...
Supernova remnants (SNRs) are considered the primary sources of Galactic cosmic ray acceleration. Particles are energized at the shock front of SNR through the diffusive shock acceleration mechanism, gaining energy by repeatedly crossing the shock. Magnetic turbulence plays a crucial role in scattering these particles back and forth; therefore, investigating this turbulence is essential for...
The Rubin and Roman telescopes will come online soon and are expected to detect over 1000 “orphan afterglows” per year: broad-band long lasting emission from a gamma-ray burst (GRB), but without the GRB. Having a method to extract the physical parameters of these orphan afterglows will give us a better understanding of the progenitor systems. We start with a model that takes physical...
We present an in-depth analysis of the timing and spectral properties of NGC 7314, a Seyfert 1.9 galaxy, using data from XMM-Newton, NuSTAR, and RXTE/PCA. Our timing analysis reveals significant variability across multiple energy bands, with fractional variability (Fvar). We observe that soft X-ray photons exhibit greater variability compared to harder photons, suggesting distinct emission...
SMC X-1 is a high-mass X-ray binary exhibiting an X-ray pulsar with a ~0.7 s spin period and a non-stationary superorbital modulation ranging from ~40 to ~65 days. Its luminosity of 5E38 erg/s makes it a local analogue of ultraluminous X-ray pulsars, powered by supercritical accretion. To investigate whether SMC X-1's superorbital modulation originates from a change in the mass accretion rate...
Physics-inspired neural networks (PINNs) have gained considerable importance in recent years in the domain of Astronomy & Astrophysics, particularly, being a potential tool to solve differential equations within the given boundary conditions, not limiting to accurate predictions but also providing efficient approach for large computations. In this work, we have focused on solving the kilonova...
Supernovae explosion (SNe) are among the most energetic astrophysical phenomena, where the ejecta from a stellar explosion collides with a dense circumstellar medium (CSM), leading to intense shock interactions and enhanced radiation output. We employ two-dimensional radiation hydrodynamics (RHD) simulations using the CASTRO code, incorporating adaptive mesh refinement (AMR) to model the...
We present a follow-up X-ray study of the redback millisecond pulsar PSR J2215+5135. PSR J2215+5135 was discovered as a radio pulsar with an orbital period of 0.17 day. It is in a compact binary system with a low-mass companion of 0.33 $\text{M}_\odot$ (Linares, et al., 2018).
Observationally, redback systems occasionally exhibit a double-peaked structure in their X-ray light curves. This...
