First results of the SUMER telescope and spectrometer on SOHO .2. Imagery and data management

SUMER - Solar Ultraviolet Measurements of Emitted Radiation - is not only an extreme ultraviolet (EUV) spectrometer capable of obtaining detailed spectra in the range from 500 to 1610 Angstrom, but, using the telescope mechanisms, it also provides monochromatic images over the full solar disk and beyond, into the corona, with high spatial resolution. We report on some aspects of the observation programmes that have already led us to a new view of many aspects of the Sun, including quiet Sun, chromospheric and transition region network, coronal hole, polar plume, prominence and active region studies. After an introduction, where we compare the SUMER imaging capabilities to previous experiments in our wavelength range, we describe the results of tests performed in order to characterize and optimize the telescope under operational conditions. We find the spatial resolution to be 1.2 are sec across the slit and 2 are sec (2 detector pixels) along the slit. Resolution and sensitivity are adequate to provide details on the structure, physical properties, and evolution of several solar features which we then present. Finally some information is given on the data availability and the data management system.