tokens: reproduces the observed interstellar extinction curve from UV to near-IR (Fitzpatrick 1999 ; Draine 2011 ). The optical results prefer the strong forward scattering with , comparable to the present near-IR values. In the near-IR, the present results can be several times larger than the WD01 prediction. Simply, the discrepancy can be explained if the larger dust grains are more dominant compared to the WD01 model. The WD01 value decreases toward longer wavelengths because the isotropic scattering by the Rayleigh scattering becomes more dominant. In the WD01 model, the typical grain size is (Draine 2011 ), which is much smaller than the near-IR wavelengths. To explain the derived large g -value, a lot of large grains may be required to cancel out the isotropic scattering by the smaller grains. However, the existence of a lot of large grains is expected to conflict with various observed properties of interstellar dust, such as interstellar depletion and wavelength dependence of interstellar extinction and polarization. This may indicate that the actual near-IR g -value is smaller than that obtained in the present study. Figure 2. Optical to near-IR scattering asymmetry factor . The present results at 1.25 and are indicated by filled red circles. The triangle, diamonds, and squares denote the results derived from Lillie Witt ( 1976 ), Witt et al. ( 1990 ), and Mattila ( 1970 ), respectively. The solid curve represents the value expected from the WD01 model with R V = 3.1 Milky Way dust (Draine 2003 ). When interstellar dust grains are exposed to UV photons, continuous near-IR emission is created as a result of the stochastic heating of the small grains and/or fluorescence by large molecules such as PAH. In fact, the UV-excited dust emission component has been observed in reflection nebulae at 1.25– wavelengths (Sellgren et al. 1992 , 1996 ). If such an emission component also exists in the general diffuse interstellar medium, the UV-excited dust emission is expected to be higher toward low Galactic latitudes because, from the Galaxy Evolution Explorer ( GALEX ) data, the near-UV to far-UV ratio in low Galactic latitudes is reported to be smaller than that in high latitudes by more than a factor of two (Figure 10 of Murthy 2014 ). The possible Galactic latitude dependence of the UV-excited dust emission would also contribute to the derived latitude dependence and may reduce the very large asymmetry factor g to the reasonable value. In this sense, the derived latitude dependence in the present study may indicate the first detection of UV-excited dust emission in the diffuse interstellar medium at 1.25 and . Similarly, to explain the very high albedo derived in the galaxy NGC 4826 in the -band, Witt et al. ( 1994 ) suggested the contribution from the near-IR dust emission in addition to the scattered light. To determine the relative contribution of the scattered light and UV-excited dust emission from the derived latitude dependence, detailed
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