The distribution of light in galaxies - The edge-on spiral NGC 5907

We present our bulge and disk decomposition of an H-band (1.68-mu-m) image of the late-type, edge-on spiral NGC 5907. We model the disk radially as a decaying exponential and vertically as a sech(z) function, and we fit the bulge with a modified Hubble profile. From these fits, we find for the disk the exponential scalelength is 4.0 kpc and the exponential scaleheight is 0.34 kpc. We also find that the bulge-to-disk luminosity ratio (B/D) is 0.05. The near-infrared scale parameters are significantly smaller than those derived from optical observations, which can be explained by assuming the edge-on disk is optically thick in absorption at visual wavelengths due to dust. In addition, the scaleheight has no significant dependence on radial distance. We also find the face-on, central surface brightness of the disk in the B pass band is 21.7 mag arcsec-2. Thus, it appears that NGC 5907 falls into the narrow range of central surface brightness that has been observed in visual studies of spiral galaxies.