Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-11-03
Astronomy and Astrophysics
Astrophysics
submitted to Icarus, 18 pages
Scientific paper
Grain alignment theory suggests that grains should be aligned in circumstellar regions and the observational data available supports this conclusion. We discuss the alignment of grains via (1) magnetic relaxation, (2) mechanical processes, and (3) radiative torques. We show that ferromagnetic relaxation is likely to be more important than superparamagnetic relaxation if the dust in circumstellar regions is similar to species recently captured in Earth atmosphere. Outflows and stellar winds provide grain streaming along magnetic field lines and therefore mechanical alignment competes with the ferromagnetic and radiative alignments. We estimate measures of grain alignment in circumstellar regions, comets and interplanetary space and conclude that in many circumstellar regions and in the interplanetary space radiative torques may constitue the major alignment mechanism which aligns grain longer axes perpendicular to the direction of magnetic field. Observations in submillimeter and microwave ranges are suggested as a means of disentangling effects of multiple scattering from those related to aligned grains.
No associations
LandOfFree
What Grain Alignment can Tell about Circumstellar Disks and Comets 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 What Grain Alignment can Tell about Circumstellar Disks and Comets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and What Grain Alignment can Tell about Circumstellar Disks and Comets will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-592012