We present a sample of 54 disk galaxies which have well developed extraplanar structures. We selected them using visual inspections from the color images of the Sloan Digital Sky Survey. Since the sizes of the extraplanar structures are comparable to the disks, they are considered as prominent stellar halos rather than large bulges. A single S´ersic profile fitted to the surface brightness along the minor-axis of the disk shows a luminosity excess in the central regions for the majority of sample galaxies. This central excess is considered to be caused by the central bulge component. The mean S´ersic index of the single component model is 1.1 ± 0.9. A double S´ersic profile model that employs n = 1 for the inner region, and varying n for the outer region, provides a better fit than the single S´ersic profile model. For a small fraction of galaxies, a S´ersic profile fitted with n = 4 for the inner region gives similar results. There is a weak tendency of increasing n with increasing luminosity and central velocity dispersion, but there is no dependence on the local background density.

Abstract
1. INTRODUCTION
2. DATA AND SAMPLE SELECTION
    2.1. Selection of Prominent Stellar Halos
3. RESULTS
    3.1. Morphological Properties of Prominent StellarHalos
    3.2. Luminosity Profiles of the Prominent Stellar Halos
    3.3. Distribution of the S´ersic Index
    3.4. Dependence on the Physical Properties of Galaxies
    3.5. Local Background Density
4. DISCUSSION AND CONCLUSIONS
REFERENCES

• Hyeong Wook Park(Pusan National University)
• Hong Bae Ann(Pusan National University) Corresponding author