Radiation MHD Simulations of AM CVn Accretion Disks

Séminaire IPAG de Omer Blaes (UCSB), jeudi 21 juin 2018 à 11h00, salle Manuel Forestini IPAG

AM CVn systems are extremely compact binary star systems consisting of a white dwarf that is accreting from a helium donor star. Interest in these systems arises primarily from the fact that they are sources of exotic classical novae and possibly even type Ia supernovae, as well as being detectable sources of gravitational waves by LISA. They are also amazing laboratories for exploring accretion disk physics. They exhibit all sorts of variability including broadband noise, superhumps, QPO’s, and normal and super-outbursts related to helium ionization instabilities. They are also generally hotter and more ionized (and therefore more electrically conducting) than outbursting accretion disks containing hydrogen. I will discuss our recent work on these systems exploring their dynamics and thermodynamics using both local and global radiation MHD simulations of the accretion flow, and will also discuss how our results might be used to explain observations of these systems.