I will review methods for solving time-dependent radiation transfer in general relativistic spacetimes and described a new method for treating radiation transfer in a five or six dimensional finite volume approach. I will also describe our efforts to apply direct transfer solutions to simulations of black hole accretion and the driving of accretion disk winds via radiation pressure.
The Event Horizon Telescope is a global effort to construct an
Earth-sized virtual radio telescope array, with the goal to make pictures and movies of two nearby supermassive black holes. A detailed theoretical understanding of black hole accretion is now crucial to interpret these observations. I will review our current efforts to model polarimetric properties of light produced in...
Emission from the Broad-line regions (BLR) in active galaxies are produced primarily by photoionization processes, driven by the continuum arising from an underlying, complex structure circumscribing the black hole. Modelling the broad-band spectral energy distribution (SED) that ionizes these gas-rich BLRs is key to understanding the various radiative processes leading to the emission...
A binary neutron star merger (BNS) is expected to produce supernova-like radioactively powered transient known as a kilonova (KN), which enters the nebular phase several days after the merger. Modelling of the ejecta in this phase has often been approached under the assumption that local thermodynamic equilibrium (LTE) is applicable. In order to test the validity of this assumption, we compare...
We present a new algorithm for radiative transfer, based on a statistical Monte-Carlo approach, that does not suffer from teleportation effects and yields smooth results. Implicit-Monte-Carlo (IMC) techniques for modelling radiative transfer exist from the 70's. However, in optically thick problems, the basic algorithm suffers from ‘teleportation’ errors, where the photons propagate faster...
Nebular [Ca II] emission can show up in the spectra of just about every type of supernovae (SNe): SNe Type Ia, core collapse SNe and of course the elusive Ca-rich transients. But what this emission can tell us, beyond there being some (how much?) calcium in the ejecta, is not well understood. I will present the early results of ongoing work to quantify this phenomena using NLTE radiative...
