Stanford 2016 PhD Dissertation:

Towards Multiwavelength Observations of Relativistic Jets from General Relativistic Magnetohydrodynamic Simulations

Abstract:

A methodology for reverse engineering current and anticipated observations of astrophysical relativistic jets using self-consistent, general relativistic magnetohydrodynamic (GRMHD) simulations is detailed from data-hosting and manipulation to mimicking instrument-specific properties such as point spread function convolution. This pipeline handles particle acceleration prescriptions, synchrotron and inverse Compton emission and absorption, Doppler boosting, time-dependent transfer of polarized radiation and light-travel time effects. Application of this pipeline to low-frequency radio observations is exemplified using the famous jet in the giant elliptical galaxy M87. High-frequency gamma-ray observations are represented by the powerful quasar 3C 279. Though the work presented here focuses on a single simulation of a magnetically arrested disk and a wind-collimated, approximately force-free jet, it can readily be adapted to simulations with different spatiotemporal resolutions and/or plasma initial conditions. Stationary, axisymmetric semi-analytic models are also developed, providing a quantitative understanding of the simulated jet flow and its electromagnetic properties. Using the 3D time-dependent \say{observing} routines for synchrotron models, predictions such as bilateral asymmetry of intensity maps and enhanced limb brightening for models with high velocity shear are advanced. Using gamma ray prescriptions in the routines resulted in rapid variability. User-friendly Python and UNIX guides are included for didactic purposes. With the advent of the state-of-the-art gamma ray Cerenkov Telescope Array, the Event Horizon Telescope– which promises to resolve Schwarzshild radius (r_S) scale features at the Galactic Center and M87– and more sophisticated GRMHD simulations with similar resolution coupled with dynamical range 10⁰r_S – 10⁵r_S, direct comparison of simulation and observation in this work may facilitate the understanding and prediction of the physical nature of relativistic jets in the near future.

 

Original version:

Towards Multiwavelength Observations of Relativistic Jets from General Relativistic Magnetohydrodynamic Simulations