Current Developments in Numerical Astrophysics
Title of Abstract
Time-Dependent General-Relativistic Radiation Transport
Ziri Younsi
Kinwah Wu (Mullard Space Science Laboratory, University College London), Luciano Rezzolla (Goethe University, Frankfurt), Yosuke Mizuno (Goethe University, Frankfurt)
Institute for Theoretical Physics, Goethe University, Frankfurt
Summary (maximum 250 words)
Calculations of the electromagnetic emissions from accreting compact objects necessitate the implementation of numerical radiation transport schemes in full general relativity. Such calculations must comprehensively include the detailed effects of special relativistic, general relativistic, absorption, emission, optical depth and geometrical effects inherent to the emissions in these systems. In the case of highly turbulent accretion flows in the vicinity of black hole event horizons, such as Sgr A* in our own galaxy, time dependence cannot be neglected and plays a pivotal role in determining the dynamics of the accretion flow, and consequently the observed emissions.

To this end we present results from a new time-dependent general-relativistic radiation transport code. In addition to incorporating all of the aforementioned effects, these calculations can be performed for any arbitrary (static) input spacetime, both analytic and numerical. Such a general approach is key to investigate other spacetimes and alternative theories of gravity. We will also discuss an extension of this code to dynamical spacetimes such as those presented in coalescing compact object binary simulations (e.g. binary black holes and neutron stars) and discuss the progress we have made thus far.


Session Time
13:30 - 15:00
Talk start