The horizon collaboration is a Theoretical and Computational Astrophysics Network funded by the US National Science Foundation from 2013-2016.  The PIs are Eliot Quataert, Jim Stone, and Charles Gammie.  Our group’s goal is to develop, deploy, and apply novel numerical methods to create predictive models of black hole accretion flows in both the low accretion rate and high accretion rate regime.

To this end, we are building a general relativistic extended magnetohydrodynamics (EMHD) model of low accretion rate flows like that in the galactic center.  These models will incorporate more realistic models for electron thermodynamics, including radiative cooling, viscosity, and conduction.

We are also building general relativistic radiation MHD models of high accretion rate disks, where radiation forces and cooling can be important for disk evolution.  In particular, we hope to understand the global evolution of black hole accretion disks in the face of thermal and viscous instabilities.

The horizon collaboration includes researchers at every career stage, from graduate student to senior faculty.

Horizon Collaboration Group Meeting, January 2015, Berkeley:


Not shown: Monika Moscibrodzka (Nijmegen), Matt Kunz (Princeton).   (back row, l to r): Mario Riquelme (U. de Chile), Francois Foucart (Berkeley), Sean Ressler (Berkeley), Ben Ryan (Illinois), Mani Chandra (Illinois), Sasha Tchekhovskoy (Berkeley), Josh Dolence (Los Alamos), Yan-Fei Jiang (CfA), Chris White (Princeton), Alwin Mao (Berkeley), Nathan Roth (UCB). (front row, l to r): Shane Davis (Virginia), Jason Dexter (MPE), Jim Stone (Princeton), Charles Gammie (Illinois), and Eliot Quataert (Berkeley).