尘埃粒子的分布

＊MRN model(Mathis, Rumpl & Nordsiek 1977) ,describes the size distribution of dust grains in the MilkWay 解析失败 (语法错误): {\displaystyle N(a)\propto a^{−3.5}}

• grains larger than ∼ 0.2μm are too heavy and remain trapped in the gravitational field of the host galaxy.
• Smaller grains (a<0.05μm) are either destroyed by sputtering or unable to travel far from formation sites as they are inefficiently pushed away by radiation pressure;