Inelastic dissipation in a freely rotating body: application to cosmic dust alignment

被引:54
作者
Lazarian, A
Efroimsky, M
机构
[1] Princeton Univ Observ, Princeton, NJ 08544 USA
[2] Harvard Univ, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA
[3] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA
关键词
magnetic fields; polarization; ISM : clouds; dust; extinction; ISM : magnetic fields; galaxies : magnetic fields;
D O I
10.1046/j.1365-8711.1999.02235.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Motivated by a recent study by Lazarian and Draine, which showed that a high degree of grain alignment of the paramagnetic dust is achievable if the rates of internal relaxation are controlled by the Barnett relaxation process, we undertake a study of an alternative mechanism of internal dissipation, namely, the inelastic dissipation of energy in oblate dust grains. We find that deformations at double frequency that were disregarded in earlier studies dominate the inelastic relaxation. Our results indicate that for sufficiently oblate grains, e.g. for grains with a 4:1 axis ratio, or/and grains formed by agglomeration, inelastic relaxation dominates the Barnett relaxation within large (a > 0.1 mu m) grains. For grains with an axis ratio less than 1:2, the inelastic relaxation is dominant for suprathermally rotating grains.
引用
收藏
页码:673 / 684
页数:12
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