Final day of the “A Universe of Black Holes” workshop with a session: “Modeling Black Hole Accretion and Outflows” – all MHD sims today…

Chris Reynolds (Univ. of Maryland) starts with – The temporal variability of model accretion disks

Had to miss this. Go check it online, Chis gives fab talks.

Julian Krolik (JHU) “The Bardeen-Petterson effect in magneto-hydrodynamics”
Krolik demonstrated large Reynolds stress…
cf ” Alignment of supermassive black hole binary orbits and spins” – Miller & Krolik 2013

Jim Stone (Princeton) “New magneto-hydrodynamic simulations of radiation pressure dominated accretion disks”

radiative transport is hard – brutal range of timescales
luminous disks can be radiation dominated
there are lurking dynamic instabilities
sees thermal instability
needs global sims, not box

code comparison – algos matter

Athena MHD code has new radiation module

back from break

Gregory Novak (Paris Observatory) “Hydrodynamic simulations of black hole fueling and feedback”

Ken Nagamine (UNLV) “Gas accretion onto a supermassive black hole: a step to model AGN feedback”

Kwangho Park (Carnegie Mellon) “Accretion onto black holes from large scales regulated by radiative feedback”

Ross Parkin (ANU) “Magnetized accretion disk turbulence”

and we are back from break:

Omer Blaes (UC Santa Barbara) “Issues in radiation dominated accretion”

very nice overview of what the issues are with the radiation dominated accretion flows
interesting technical details on radiation instabilities
their sims show photon bubbles transforming to Parker instabilities – are there real photon bubbles?
interesting alternative scenario – thermally inhomogenous disks
explains a lot, but, does introduce a heck of a lot of free parameters…

state of sims: close to just brute force solving radiative disks on global scale – maybe 5 yrs

Daniel Proga (Univ. of Nevada) “The physics of mass outflows driven by radiation from active galactic nuclei”

overview of radiatively driven mass outflows, especially polar collimated jets and winds
link to broadline regions, but he lost me – too many slides too fast

Chris Fragile (College of Charleston) “General relativistic radiation magneto-hydrodynamic simulations of black hole accretion”

Talks are online – podcast, audio, video and, in due course, pdf of slides, speakers willing.