A model for the distribution of stars in the disk and the spheroid of our Galaxy is reexamined from an edge-on view of the Galaxy obtained by selecting infrared sources from the IRAS Point Source Catalog. The sources are counted as a function of galactic latitude. longitude and 12μm 12μm apparent magnitude. The source counts are reasonably separated into the disk component and the spheroid component contributions and each of the contributions is further interpreted as a convolution of a spatial density distribution and a luminosity function based on the least-square fit method. The spatial density of the disk component has an exponential radial scale length of hR∼2.6kpc hR∼2.6kpc and the vertical distribution follows a canonical sech2 sech2 law with a scale height hz∼240pc hz∼240pc . The distribution of the spheroid component can be represented by an oblate spheriod with an axis ratio k∼0.61 k∼0.61 and a de Vaucouleurs' r1/4 r1/4 law with an effective radius of Re∼120pc Re∼120pc . The steep density gradient of the spheroid component is consistent with that of late M giants in the central bulge. The luminosity functions of the disk and the spheroid component stars resemble respectively those of the K luminosity function of disk M giants (Garwood and Jones 1986) and the bolometric luminosity function of M giants in bulge fields (Frogel et al, 1990).

• 강용희(경북대학교 사범대학 지구과학교육과) | Gang Yong-Hui