1 Introduction

A large-scale photographic survey of the southern Milky Way in the classic Johnson passbands U,B,V and R was begun in 1971 by obtaining images at the site of the European Southern Observatory (ESO) at La Silla/Chile (Schlosser 1971). This program was then extended to the ultraviolet in 1993, when the GAUSS camera was part of the German Spacelab Mission D-2, flewn on the space shuttle Columbia (Schlosser 1993).

Numerous surface photometries of the Milky Way have been published previously, the major earlier ones being those of Pannekoek (1933) and Pannekoek & Koelbloed (1949). Elsässer & Haug (1960) have been the first to present photoelectric measurements of the Milky Way with a reasonable resolution in well defined passbands. Other large scale surface photometries since then are those of Smith et al. (1970); Pfleiderer & Mayer (1971); Classen (1971); Weinberg (1981); Toller (1989) and the Bochum ones (Paper VII and Paper VIII). However, all of these photometries are restricted to spectral domains close to the visual.

In the ultraviolet, surface photometries have been presented only for smaller areas like some reflection nebulae (Gordon et al. 1994; Witt et al. 1992) or cirrus clouds (Haikala et al. 1995). In the 140nm - 180nm passband, the FAUST FUV telescope has measured about 5000 sources spread over the sky (Bowyer et al. 1993) and some efforts have been made to measure the ultraviolet sky brightness or background radiation (Joubert et al. 1983; Henry 1991; Bowyer 1991; Henry & Murthy 1993). More recent analysis concerning the dust-scattering and the diffuse radiation in the FUV has been conducted by Sasseen & Deharveng (1996) and Witt et al. (1997) (and references therein).

We here present surface photometries in the ultraviolet on larger scales. In Sects. 2 and 3 we give a short overview on the instrumentation and the data used for the photometries. The reduction is described in detail in Sect. 4, and in Sect. 5 we present the resulting maps yielding a comprehensive picture of the Southern Milky Way at 217nm and 280nm (see also Schmidtobreick 1997 and Wiemann 1997).