|Title||The baryon fraction in group-sized halos|
|Author||Dr Alastair Sanderson|
|Description||The baryon fraction (f_b) in collapsed massive halos has great cosmological significance, and comprises hot gas and stars --- both in galaxies and the intracluster light (ICL). While the gas mass is known to be depleted in groups, it is not clear if the missing baryons have been ejected from the halo or are simply locked up in stars. The best current study suggests an increasing ICL fraction in groups offsets a declining gas fraction, implying a universal f_b, but this is based on only 2 low mass groups, with only estimated stellar baryon masses. We propose to observe the only 4 poor groups for which a state-of-the-art measurement of intragroup stellar baryons has been made, to map the hot gas and thereby discriminate definitively between these two scenarios.|
|Publication||No observations found associated with the current proposal|
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2011-11-19T00:00:00Z, 055522, 17.56_20190403_1200. https://doi.org/10.5270/esa-uuxjco2|