ESA uses cookies to track visits to our website only, no personal information is collected.
By continuing to use the site you are agreeing to our use of cookies. OK Find out more about our cookie policy.
Currently, sci.esa.int is under review and not being updated. For the latest information and news from ESA science missions and scientific results, please visit esa.int. For a comprehensive overview of ESA’s Science Programme and its missions, please refer to science.esa.int. For in-depth technical information aimed at ESA's scientific communities, you may also wish to consult cosmos.esa.int.
Date: 29 January 2001 Satellite: XMM-Newton Depicts: Spectrum from NGC 253 Copyright: Image courtesy of M. Bauer, Max-Planck Institute for extraterrestrial Physics, Germany and ESA Show in archive: true
The spectrum is dominated by Ly emission lines of silicon, magnesium, neon, oxygen, nitrogen and carbon together with their helium-state emission lines. Additionally we see emission lines from iron. The line strength changes with distance from the galactic centre as the outflowing gas cools. Temperatures in the outflow are between 0.79 keV in the centre of the galaxy down to 0.21 keV furthest away from the starburst nucleus. The iron lines point at a primarily collisional ionized plasma. They also show features of a non-equilibrium plasma especially in region SE 1, where we see additional emission from delayed recombining Fe XVIII.