ИСТИНА

We suggest and justify a new photometric method enabling the derivation of the relative thickness of a galactic disk from the two-dimensional surface-brightness distribution of the galaxy in the plane of the sky. We stress two distinct advantages of our method: firstly, it provides an individual estimate for every galaxy, beyond a statistical approach, and secondly, for the galaxies which orientation differs from edge-on it allows to confront its vertical structure with the radial brightness profile properties. The method has been tested and calibrated using images of model galaxies. It allows us to compare our results with observational thicknesses of edge-on galaxies. The method is applied to a small sample of images from of the SDSS and S4G of disk galaxies with known radial piece-wise-exponential (with a flatter outer profile) surface-brightness distributions. The accuracy of data is sufficient to derive the thickness of both the inner and outer disks for a few galaxies. Matching the distribution of radial scale and relative thickness in inner and outer disks can lead to interesting conclusions about physics and origin of galactic disks.