消光曲线

银河系消光曲线

• 核球方向，近红外波段的消光曲线，还是比较陡[1]
• 2175A bump是由C尘埃贡献，而整体的紫外消光是C尘埃和Si尘埃都贡献[2]

常用消光曲线

• simple power-law $\propto \lambda ^{-1}$
• 在0.9mu到5mu可以近似为$\propto \lambda ^{-1.7}$
• 9.7(Si-O),18mu(O-Si-O)有硅酸盐吸收，3.4mu有烃吸收，6.2mu有PAH吸收
• the Milky Way (MW) extinction curve (with a prominent bump at 2175)理论解释 [3]

尺度小于0.02mu的carbonaceous grains，石墨的π电子的激发吸收，PAH类似

• the featureless Small Magellanic Cloud (SMC) extinction curve which steeply rises with inverse wavelength from near-IR to far-UV
• the LargeMagellanic Cloud (LMC) curve being intermediate between that of the MW and the SMC;
• the featureless “Calzetti” attenuation law for the dust in local starburst galaxies (Calzetti et al. 1994);
• the relatively flat “Maiolino” extinction law for the dust in the dense circumnuclear region of AGNs (Maiolino et al. 2001) where the dust size distribution is skewed toward large grains

以上参见图1 [4]

类星体中的尘埃

• 一种认为和SMC差不多 Hopkins et al. (2004)
• 一种认为比较平 (Czerny et al. 2004; Gaskell et al. 2004).

see also 尘埃粒子的分布'

ARA&A文献：[5]