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 (带SVG或PNG备选的MathML（建议用于现代的浏览器和辅助工具）：从服务器“https://wikimedia.org/api/rest_v1/”返回无效的响应（“Math extension cannot connect to Restbase.”）：): {\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;