Most galaxy formation models predict that massive low-redshift disk galaxies areembedded in extended hot halos of externally accreted gas. Yet observationalstudies have so far failed to detect soft X-ray emission from such halos. Ourcosmological simulations, the first to produce fully realistic disk galaxies,suggest this is within reach but requires a factor of 10 increase in sensitivitycompared to existing X-ray studies. We propose a deep observation of the massivespiral NGC5746, to decisively test for the presence of such a halo and constrainits properties. A detection will confirm a basic tenet of disk galaxy formationmodels, whereas a non-detection will seriously challenge these models and imposenew constraints on the growth mode and feedback history of disk galaxies.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2011-01-10T14:54:00Z/2011-02-10T13:41:24Z
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 Jesper Rasmussen, 2012, 'A deep search for a hot halo of NGC 5746: Constraining disk galaxy formation', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-7v6dp39
