Ray-Tracing Black Holes at Unprecedented Resolution
Ray-tracing state-of-the-art simulation data enables the H-AMR collaboration to explore the connections between the theory, numerical simulations and observations. To make such images and spectra we use general relativistic ray-tracing (GRRT) codes such as BHOSS and xTrack to shoot photons directly through H-AMR data. We are also developing our own ray-tracing code which is capable of producing Comptonized spectra and images at the extreme resolutions enabled by H-AMR. Below you see an example of a ray-traced image of the highest-ever resolution GRMHD simulation (video) relevant to supermassive black hole M87 in radio (230 GHz). The high resolution allows us to quantify the effects of small-scale accretion disk turbulence on the generated images and lightcurves, which would not be possible with other GRMHD codes. This image was made by my collaborator Koushik Chatterjee in BHOSS.
QPOs in Black Hole Lightcurves
Our group also quantifies the (spectral) variability in black hole lightcurves using general relativistic ray-tracing (GRRT) . As an example, the ray-traced X-Ray light-curve of a simulation of a highly tilted accretion disk (video) is shown below (made by collaborator Andrew West and Henric Krawvzynski). These QPOs are caused by precession of the accretion disk and radial epicyclic oscillations seeded at the tearing radius. Simultaneous detection of both QPO types can allow observers to measure the mass and spin of black holes.
