The X-ray isophote shapes of elliptical galaxies probe both the shape and radialdistribution of the gravitating mass essentially independently of th temperatureprofile of the hot gas. We propose to observe the elliptical NGC 3923 with XMMto obtain accurate measurements of the ellipticity of the X-ray emissionextending out to the faintest isophotes detected with the ROSAT PSPC (10 arcmin,virgul90 kpc) whereas ROSAT only obtained useful ellipticity constraints within 1.5arcmin. Consequently, our XMM observation will definitively answer the questionsof whether the mass is more elongated than the stars and whether the radialmass density profile is shallower than the CDM NFW profile. These results willthus provide important tests of cosmological theories of structure formation.
Instrument
EMOS1, EMOS2, EPN, RGS1, RGS2
Temporal Coverage
2002-01-03T19:56:50Z/2002-01-04T08:35:43Z
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, Prof David Buote, 2003, 'X-Ray Isophote Shapes and the Dark Matter Halo of NGC 3923', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-uvk3670
