51 citations · 319 across the 25 of their papers we have counts for
27 papers
Hybrid disc geometry for shocked accretion flows: Unveiling QPOs in black hole X-ray binaries
Monu Singh, Sudip Kumar Garain, Santabrata Das
We investigate the efficacy of semi-analytical global accretion solutions in capturing the flow properties observed in two-dimensional numerical simulations of shocked accretion on…
Simulation based parameter space for shock in transonic, sub-Keplerian accretion flow onto non-rotating black holes
Aishi Dasadhikary, Sudip K Garain
Non-dissipative, transonic, sub-Keplerian accretion flow onto black holes is characterized by two conserved parameters: specific energy and specific angular momentum of the flow. F…
Bridging X-ray Polarization with Timing & Spectroscopic Parameters of a galactic black hole: Swift J1727.8-1613
Arka Chatterjee, Sujoy K. Nath, Kaushik Chatterjee +5
We report the discovery of a correlated energy-dependent time lag and degree of polarization for Swift J1727.8-1613 during its 2023 outburst. The energy-dependent time lag is measu…
Outflow from unmagnetized shocked radiative transonic accretion disk around a black hole
Arghya Chaudhuri, Apurba Ghosh, Sudip K Garain
We study outflow from an unmagnetized, shocked accretion disk around a non-rotating super-massive black hole using multidimensional hydrodynamics simulation with radiative cooling.…
A general relativistic hydrodynamic simulation code for studying advective, sub-Keplerian accretion flow onto black holes
Sudip K Garain
In this paper, we describe a general relativistic hydrodynamics simulation code which is developed to simulate advective accretion flow onto black holes. We are particularly intere…
General Relativistic Hydrodynamic Simulations around Accreting Black Holes
Sudip K Garain, Pranayjit Dey
Strong gravity in the immediate vicinity of compact objects (e.g., black holes, neutron stars) necessitates inclusion of general relativistic effects. Traditionally, pseudo-Newtoni…
Three Dimensional Simulations of Advective, Sub-Keplerian Accretion Flow onto Non-rotating Black Holes
Sudip K Garain, Jinho Kim
We study the time evolution of sub-Keplerian transonic accretion flow onto a non-rotating black hole using a three-dimensional, inviscid hydrodynamics simulation code. Prior two-di…
Multidimensional Generalized Riemann Problem Solver for Maxwell's Equations
Arijit Hazra, Dinshaw S. Balsara, Praveen Chandrashekar +1
Approximate multidimensional Riemann solvers are essential building blocks in designing globally constraint-preserving finite volume time domain (FVTD) and discontinuous Galerkin t…
Technologies for supporting high-order geodesic mesh frameworks for computational astrophysics and space sciences
V. Florinski, D. S. Balsara, S. Garain +1
Many important problems in astrophysics, space physics, and geophysics involve flows of (possibly ionized) gases in the vicinity of a spherical object, such as a star or planet. Th…
Effects of Magnetic Field Loops on the Dynamics of Advective Accretion Flows and Jets around a Schwarzschild Blackhole
Sudip K. Garain, Dinshaw S Balsara, Sandip K Chakrabarti +1
Magnetic fields advected along with low angular momentum accretion flows predominantly become toroidal due to the strong azimuthal velocity close to a black hole. We study self-con…
Efficient, Divergence-Free, High Order MHD on 3D Spherical Meshes with Optimal Geodesic Meshing
Dinshaw S. Balsara, Vladimir Florinski, Sudip Garain +2
There is a great need in several areas of astrophysics and space-physics to carry out high order of accuracy, divergence-free MHD simulations on spherical meshes. This requires us…
Turbulent dynamo in a weakly ionized medium
Siyao Xu, Sudip K. Garain, Dinshaw S. Balsara +1
The small-scale turbulent dynamo is an important process contributing to the cosmic magnetization. In partially ionized astrophysical plasmas, the dynamo growth of magnetic energy…
General Relativistic Numerical Simulation of sub-Keplerian Transonic Accretion Flows onto Rotating Black Holes: Kerr Spacetime
Jinho Kim, Sudip K. Garain, Sandip K. Chakrabarti +1
We study time evolution of sub-Keplerian transonic accretion flows onto black holes using a general relativistic numerical simulation code. We perform simulations around the black…
Images and Spectra of Time Dependent Two Component Advective Flow in Presence of Outflows
Arka Chatterjee, Sandip K. Chakrabarti, Himadri Ghosh +1
Two Component Advective Flow (TCAF) successfully explains the spectral and tem- poral properties of outbursting or persistent sources. Images of static TCAF with Compton cloud or C…
General Relativistic Numerical Simulation of sub-Keplerian Transonic Accretion Flows onto Black Holes: Schwarzschild Spacetime
Jinho Kim, Sudip K. Garain, Dinshaw S. Balsara +1
We study time evolution of sub-Keplerian transonic accretion flows onto black holes using a general relativistic numerical simulation code. We perform simulations in Schwarzschild…
A High-Order Relativistic Two-Fluid Electrodynamic Scheme with Consistent Reconstruction of Electromagnetic Fields and a Multidimensional Riemann Solver for Electromagnetism
Dinshaw S. Balsara, Takanobu Amano, Sudip Garain +1
In various astrophysics settings it is common to have a two-fluid relativistic plasma that interacts with the electromagnetic field. While it is common to ignore the displacement c…
Riemann Solvers and Alfven Waves in Black Hole Magnetospheres
Brian Punsly, Dinshaw Balsara, Jinho Kim +1
In the magnetosphere of a rotating black hole, an inner Alfven critical surface (IACS) must be crossed by inflowing plasma. Inside the IACS, Alfven waves are inward directed toward…
Segregation of a Keplerian disc and sub-Keplerian halo from a Transonic flow around a Black Hole by Viscosity and Cooling processes
Kinsuk Giri, Sudip K. Garain, Sandip K. Chakrabarti
A black hole accretion is necessarily transonic. In presence of sufficiently high viscosity and cooling effects, a low-angular momentum transonic flow can become a standard Kepleri…
Numerical Simulation Of Spectral And Timing Properties Of Galactic Black Holes
Sudip Kumar Garain
A black hole accretion may have both the Keplerian and the sub-Keplerian components. We consider the most general accretion flow configuration, namely, two-component advective flow…
Numerical Simulation of Spectral and Timing Properties of a Two Component Advective Flow around a Black Hole
Sudip K Garain, Himadri Ghosh, Sandip K Chakrabarti
We study the spectral and timing properties of a two component advective flow (TCAF) around a black hole by numerical simulation. Several cases have been simulated by varying the K…
Quasi Periodic Oscillations in a Radiative Transonic Flow: Results of a Coupled Monte Carlo-TVD Simulation
Sudip K. Garain, Himadri Ghosh, Sandip K. Chakrabarti
Low and intermediate frequency quasi-periodic oscillations (QPOs) in black hole candidates are believed to be due to oscillations of the Comptonizing regions in an accretion flow.…
How Plasma Composition affects the relativistic flows and the emergent spectra
Indranil Chattopadhyay, Sudip Garain, Himadri Ghosh
It has been recently shown that transonic electron positron fluid is the least relativistic, compared to the fluid containing finite proportion of baryons. We compute spectra from…
Effect of equation of state and composition on relativistic flows
I. Chattopadhyay, S. Mandal, H. Ghosh +3
The thermal state of the fluid is governed by the ratio of the thermal and the rest energy. This brings the composition of the fluid into the picture. Although, fluid composed of l…
Effects of Compton Cooling on outflows in a Two Component Accretion Flow around a Black Hole: Results of a Coupled Monte Carlo-TVD Simulation
Sudip K. Garain, Himadri Ghosh. Sandip K. Chakrabarti
The effect of cooling on the outflow rate from an accretion disk around a black hole is investigated using a coupled Monte Carlo Total Variation Diminishing code. A correlation bet…