Where, and in what form, are most of the Baryons in the local universe? At highredshift we seem to know the answer, but a substantial fraction of the baryonsseem to be missing at low redshift! It is very likely that this material residesin the haloes of galaxies and galaxy groups, at densities and temperatures thatmake it hard to detect by conventional means. This material should be detectablethrough the OVII and OVIII absorption of a background source. However, we arguethat observation of random sight-lines is not effective, and that we mustdeliberately target lines of sight that pass through the centers of galaxygroups. Although very rare, we have identified two particularly favourablesight-lines that will allow us to detect this important baryon reservoir.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2005-02-02T17:42:30Z/2005-02-05T17:53:03Z
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 RICHARD BOWER, 2006, 'DOES HOT GAS PERVADE THE LOCAL UNIVERSE', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-k9vy1k6
