The horizon collaboration will continue under funding provided by the US National Science Foundation from 2017-2020.   The PIs are  Eliot Quataert, Jim Stone, Matt Kunz, and Charles Gammie.  Our group’s goal was 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.

The horizon collaboration was initially supported by a Theoretical and Computational Astrophysics Network (TCAN) funded by the US National Science Foundation from 2013-2018.  The PIs were Eliot Quataert, Jim Stone, and Charles Gammie.

Under TCAN funding, we built a general relativistic extended magnetohydrodynamics (EMHD) model of low accretion rate flows like that in the galactic center.  These models incorporated realistic models for electron thermodynamics, including radiative cooling, viscosity, and conduction.

We also built general relativistic radiation MHD models of high accretion rate disks, where radiation forces and cooling can be important for disk evolution.  In particular, we sought 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).