摘要：We model the ~ 1–19 μ m infrared (IR) extinction curve toward the Galactic Center (GC) in terms of the standard silicate-graphite interstellar dust model.The grains are taken to have a power law size distribution with an exponential decay above some size.The best-fit model for the GC IR extinction constrains the visual extinction to be A V ~ 38–42 mag.The limitation of the model, i.e., its difficulty in simultaneously reproducing both the steep ~ 1–3 μ m near-IR extinction and the flat ~ 3–8 μ m mid-IR extinction is discussed.We argue that this difficulty could be alleviated by attributing the extinction toward the GC to a combination of dust in different environments: dust in diffuse regions (characterized by small R V and steep near-IR extinction), and dust in dense regions (characterized by large R V and flat UV extinction). Key words ISM: dust extinction—infrared: ISM—Galaxy: center.
关键词：ISM: dust ;extinction—infrared: ISM—Galaxy: center
