Most galaxy groups contain recent or impending mergers, and therefore are not indynamical equilibrium. However, galaxy groups with declining velocity dispersionprofiles (VDPs) could be relaxed: theoretical descriptions of equilibriumsystems frequently require VDPs that decrease with distance from the center. Wehave assembled a sample of such galaxy groups; each has a complete set ofoptical spectra as well as extended X-ray emission detected by ROSAT. We wouldlike to determine whether the gas temperature in these systems declinessimilarly to the VDP. Our measurements would provide unprecedented constraintson the relationship between gas temperature and velocity dispersion withinindividual poor groups of galaxies.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2003-05-26T15:33:50Z/2003-05-26T19:42:23Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs 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 Earths 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.
European Space Agency, Dr Andisheh Mahdavi, 2004, 'Temperature Structure of Apparently Relaxed Galaxy Groups', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-a4ie871
