Grain Settling and the Dead Zone in Protostellar Disks

Details Grain Settling and the Dead Zone in Protostellar Disks Grain Settling and the Dead Zone in Protostellar Disks

Jan 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009aas...21344101t&link_type=abstract

American Astronomical Society, AAS Meeting #213, #441.01; Bulletin of the American Astronomical Society, Vol. 41, p.317

Astronomy and Astrophysics

Astronomy

1

Scientific paper

A basic process concentrating the heavy elements during planet formation is the settling of primordial dust particles in protostellar disks due to the component of the stellar gravity perpendicular to the disk plane. The effectiveness of the settling depends on the strength and distribution of turbulence in the disk gas. The magneto-rotational instability drives turbulence only in active layers near the top and bottom surfaces of the disk where stellar X-rays produce sufficient ionization for good coupling of the gas to magnetic fields. Much of the disk interior remains laminar and is a so-called dead zone. We explore the consequences of the dead zone for grain settling and disk evolution. Recombination on the grain surfaces is efficient, so that the movements of the particles relative to the gas determine whether the active layers (1) grow over time through reduced recombination rates as grains are lost by settling, (2) shrink over time as the turbulence lifts grains out of the dead zone, or (3) vary episodically. We make 3-D stratified shearing-box resistive MHD calculations, tracking the movements of the grains and solving a time-dependent ionization-recombination reaction network, so that the back-reaction of the dust on the electrical resistivity of the gas is explicitly included. We examine how the dead zone governs the distribution of the grains through the disk thickness, and how the grains in turn affect the dead zone size and the flow of gas through the disk to the star.

Affiliated with

Also associated with

No associations

Rating

Grain Settling and the Dead Zone in Protostellar Disks does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Grain Settling and the Dead Zone in Protostellar Disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Grain Settling and the Dead Zone in Protostellar Disks will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1703547