Convection Affects Magnetic Turbulence in White Dwarf Accretion Disks

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

• Matthew Coleman (IAS, Princeton)
• Monday 29 January 2018, 14:00-15:00
• MR14, Centre for Mathematical Sciences, Wilberforce Road, Cambridge.

If you have a question about this talk, please contact Dr William Béthune.

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 Seminars series.

This talk is included in these lists:

• All CMS events
• CMS Events
• Cambridge Astronomy Talks
• Cosmology, Astrophysics and General Relativity
• DAMTP Astrophysics Seminars
• DAMTP info aggregator
• Interested Talks
• MR14, Centre for Mathematical Sciences, Wilberforce Road, Cambridge
• bld31

Note that ex-directory lists are not shown.