# Samik MitraIndian Institute of Technology Guwahati | IIT Guwahati · Department of Physics

Samik Mitra

Master of Science

Prime Minister's Research Fellow in Theoretical and Computational Astrophysics

## About

8

Publications

3,866

Reads

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8

Citations

Introduction

Hi, all! I am an aspiring Astrophysicist who is curious about the universe. Love working on accretion flows around the compact objects, MHD, and Black hole shadows. Always open to discussion.

Education

July 2016 - May 2018

September 2013 - May 2016

## Publications

Publications (8)

We examine the effect of thermal conduction on the low-angular momentum hot accretion flow (HAF) around non-rotating black holes accreting mass at very low rate. While doing so, we adopt the conductive heat flux in the saturated form, and solve the set of dynamical equations corresponding to a steady, axisymmetric, viscous, advective accretion flow...

We examine the effect of thermal conduction on the low-angular momentum hot accretion flow (HAF) around non-rotating black holes accreting mass at very low rate. While doing so, we adopt the conductive heat flux in the saturated form, and solve the set of dynamical equations corresponding to a steady, axisymmetric, viscous, advective accretion flow...

We examine the effect of thermal conduction on the low-angular momentum hot accretion flow (HAF) around non-rotating black holes accreting mass at very low rate. While doing so, we adopt the conductive heat flux in the saturated form, and solve the set of dynamical equations corresponding to a steady, axisymmetric, viscous, advective accretion flow...

We present a novel approach to study the global structure of steady, axisymmetric, advective, magnetohydrodynamic (MHD) accretion flow around black holes in full general relativity (GR). Considering ideal MHD conditions and relativistic equation of state (REoS), we solve the governing equations to obtain all possible smooth global accretion solutio...

We study the relativistic, inviscid, advective accretion flow around the black holes and investigate a key feature of the accretion flow, namely the shock waves. We observe that the shock-induced accretion solutions are prevalent and such solutions are commonly obtained for a wide range of the flow parameters, such as energy (${\cal E}$) and angula...

We study the relativistic, inviscid, advective accretion flow around the black holes and investigate a key feature of the accretion flow, namely the shock waves. We observe that the shock-induced accretion solutions are prevalent and such solutions are commonly obtained for a wide range of the flow parameters, such as energy (${\cal E}$) and angula...

In this poster, we present a novel formalism to explain the magnetohydrodynamics flow around a black hole in full general relativity.
Description: https://astron-soc.in/asi2022/poster-information/ASI2022_600

We present a novel approach to study the global structure of steady, axisymmetric, advective, geometrically thin, magnetohydrodynamic (MHD) accretion flow around black holes in full general relativity (GR). Considering ideal MHD conditions and relativistic equation of state (REoS), we solve the governing equations to obtain all possible smooth glob...

## Questions

Questions (6)

All the GRMHD numerical simulations use the 3+1 decomposed form. What is the advantage of using this formalism, such as Wilson, Valencia, covariant etc.

Is there any publicly available code to understand the photon trajectories using Mathematica (other programming languages are also useful)? Please provide some links if possible.

We have seen in our paper, that for a 10 solar mass non-rotating BH, magnetic field strength can reach up to 10^(5 to 6) Gauss close to the horizon. Now, if we notice the observation of EHT, they report for a 10^9 solar mass BH, field strength reaches up to 1-30 Gauss near the horizon. So, is there any specific explanation for how the magnetic flux changes from stellar to supermassive BHs?

Recent numerical simulations show that the inner part of the disk seems to oscillate in presence of a Large scale magnetic field or when the disk is in MAD state. So, can we correlate this sort of behaviour with the variability of the source?

The recent development of EHT images influenced us to study the shadow of a BH in more detail, as we can extract some information about the source. But I feel there is no strong evidence or support for determining the spin of the compact source.

Your comments are welcome.

We all know that accretion disks around BHs are presumably be magnetized in nature. If we consider ideal MHD, we know magnetic fields are frozen within the plasmas. Now, magnetic fields are turbulent, so can they help in raising the temperature of the disk? And is it significant?