Recent discoveries hint to the existence of a population of unusual massconcentrations called fossil groups. Their commonness is likely underestimateddue to biases in the optical and the reluctance to recognize new classes ofobjects. Proposed here are detailed observations of two new fossil groupsselected from a statistically complete X-ray survey. We seek to confirm thegroup-like nature of the X-ray emission thus validating their classification asfossil groups. With positive results we will place more stringent limits on thespatial density of these objects. We will measure accurate luminosities,temperatures, and mass profiles. This will facilitate a comparison to normalgroups and an investigation of the formation processes for fossil groups.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2004-04-30T17:06:58Z/2004-06-09T17:40:01Z
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 CHRISTOPHER MULLIS, 2005, 'FOSSIL GROUPS - AN EMERGING CLASS OF MASS CONCENTRATIONS', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-k1oebt8
