One of the main difficulties in measuring the dark matter content of ellipticalgalaxies is that the majority are embedded in the dark matter halos of groupsand clusters. NGC 4555 is currently the only truly isolated elliptical known tohave an extensive dark matter halo, and we propose to follow up our previousChandra observation with a deep XMM-Newton pointing. We expect to trace the massprofile to virgul130 kpc (5.), allowing determination of parameters such as haloconcentration, total system mass, and baryon fraction, which can be comparedwith the predictions of galaxy simulations. We will also measure the abundanceprofile, providing insight into the enrichment history of this unusual andimportant galaxy.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2006-06-24T21:34:01Z/2006-06-25T21:35:58Z
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 Ewan O'Sullivan, 2007, 'Dark matter in elliptical galaxies - mapping the isolated elliptical NGC 4555', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-n23s4rd
