7–11 Sept 2026
Cefalù
Europe/Rome timezone

Comparing 3D GRMHD Simulation Outputs with Observations of Black Hole Transients

Not scheduled
20m
Cefalù

Cefalù

Cefalù, province of Palermo, Sicily. Sala delle Capriate in the Town Hall (Piazza Duomo).
Poster

Speaker

Emrah Kalemci (Sabanci University)

Description

We present a framework that combines state-of-the-art three-dimensional general relativistic magnetohydrodynamic (3D GRMHD) simulations with radiative transfer calculations to directly compare theoretical predictions with multiwavelength observations of Galactic black hole transients (GBHT). Using the H-AMR code, we simulate black hole accretion flows in both SANE and MAD magnetic configurations across different Eddington-scaled luminosities. To emulate outburst evolution, we apply a rescaling prescription that artificially shortens relevant accretion timescales while preserving the physical relationships between density, magnetic field, and radiation energy densities.
Simulation outputs are post-processed with the RAPTOR ray-tracing code to generate synchrotron and synchrotron self-Compton (SSC) spectra, light curves, and synthetic images. We further employ SIXTE to produce X-ray spectra corresponding to current and future observatories, enabling direct observational comparisons. Our framework will enable the reconstruction of hardness–intensity diagram from first-principles simulations and opens a pathway toward studying timing properties, variability, and state transitions in unprecedented detail.
In this presentation, we will report on initial results (SEDs, X-ray spectra, synthetic images) below 10^-5 Eddington Luminosity, and report on future improvements to the current framework. The X-ray spectra at low luminosities reproduce photon indices consistent with observed GBHT populations. Three-dimensional reconstructions of emission regions show that synchrotron photons predominantly originate near the event horizon and the jet sheath, while SSC photons are produced over a broader spatial extent.

Author

Emrah Kalemci (Sabanci University)

Co-authors

Ms Berre Z. Donmez (Sabanci University) Mr Efe Oztaban (Sabanci University) Dr Jordy Davelaar (Princeton University) Khushi Taori Dr Matthew Liska T. P. (Georgia Institute of Technology)

Presentation materials