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Up: Three-dimensional modelling of edge-on galaxies


1 Introduction

Global parameters of galactic disks can be used to constrain the formation process as well as the evolution of disk galaxies. Recently it has become possible to deduce parameters such as scalelength or central surface density from numerical or semi-analytical self-consistent galaxy formation models (Syer et al. [1999]; Mo et al. [1998]; Dalcanton et al. [1997]) and compare the results with observed values. Observationally the Hubble Deep Field gives the opportunity to study morphological features and simple structural parameters for galaxies even at high redshifts (Takamiya [1999]; Marleau & Simard [1998]; Fasano & Filippi [1998]).

Former statistical studies providing sets of homogeneously derived parameters for nearby galaxy samples are those of de Jong ([1996b]) using a two-dimensional and of Courteau ([1996]) with a one-dimensional decomposition technique.

However, so far only a few statistical studies based on high quality CCD data (de Grijs [1998]; Barteldrees & Dettmar [1994]; hereafter Paper I) have addressed the actual three-dimensional structure of disk galaxies with regard to the stellar distribution perpendicular to the plane (z-direction) and taking into account an outer truncation (cut-off radius) for the disk, first introduced by van der Kruit & Searle ([1981a]).

While the stellar distribution perpendicular to the plane (z-profile) could result from various "heating'' processes during the galactic evolution (Toth & Ostriker [1992]; Hernquist & Mihos [1995]), the cut-off radius can be used to constrain either the angular momentum of a protocloud (van der Kruit [1987]) or possible starformation thresholds in the gaseous disk (Kennicutt [1989]).

In the following, we have compiled parameters of galactic disks for a total of 31 edge-on galaxies in different optical filters of which 17 objects have been already discussed in Paper I. One goal of our detailed comparison of several independent fitting procedures is to study the influence of the applied techniques on resulting disk parameters. It also provides the data base for statistical analysis addressing some of the above mentioned questions (e.g., Pohlen et al. [2000]). For 14 objects surface photometric data are given for the first time in Appendix A.


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