Description |
Massive clusters of galaxies currently offer two complementary approaches to cosmology, through studies of cluster gas-mass fractions and the growth of cosmic structure. We propose to pursue both of these approaches simultaneously by completing X-ray follow-up of the MACS sample. X-ray observations of this sample, the leading, statistically complete sample of very massive clusters, have already proved to be a powerful cosmological tool. The proposed observations would significantly improve our understanding of cluster scaling relations for the growth of structure, allow a detailed statistical study of the evolution and impact of cool clusters cores, and identify hot, relaxed clusters suitable for cosmological studies through the gas-mass fraction method. |
Mission Description |
The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earth's atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis. |