University of Cambridge > Talks.cam > DAMTP Astrophysics Seminar > Convection Affects Magnetic Turbulence in White Dwarf Accretion Disks

Convection Affects Magnetic Turbulence in White Dwarf Accretion Disks

Add to your list(s) Download to your calendar using vCal

If you have a question about this talk, please contact Dr. Yufeng Lin.

I examine the accretion disks which power outbursts in two types of white dwarf binary systems: dwarf novae (DNe) and AM C Vns. Accretion disks in these systems are thermally unstable, causing some of the observed variations. The source of “normal outbursts” in these systems ultimately originates from ionization transitions (H for DNe and He for AM C Vns). These ionization transitions cause significant temperature dependence in opacities and equation of states, culminating in the occurrence of convection within these accretion disks. Local stratified shearing-box simulations were used to show that this convection has a significant impact on the turbulence and dynamos generated by the magnetorotational instability (MRI). Most notably, convection enhances the stress to pressure ratio, often denoted by alpha. These results were then incorporated into the disk instability model to generate the first theoretical lightcurves for dwarf novae outbursts which incorporate MRI physics.

This talk is part of the DAMTP Astrophysics Seminar series.

Tell a friend about this talk:

This talk is included in these lists:

Note that ex-directory lists are not shown.

 

© 2006-2017 Talks.cam, University of Cambridge. Contact Us | Help and Documentation | Privacy and Publicity