We propose a 30 ks XMM-Newton observation of the merging groups NGC 7618 and UGC12491. Group-group mergers play an key role in the formation of structure in theUniverse, but have been poorly studied relative to galaxy clusters because oftheir lower X-ray luminosity. These two groups are nearby (74 Mpc), X-raybright, and separated by only 280 kpc on the sky. Our goal is to map thethermodynamic parameters of the gas across the merger to constrain the dynamicsof the merger. A short Chandra observation of NGC 7618 revealed a sharp surfacebrightness discontinuity probably related to motion of the group core due to themerger. The NGC 7618/UGC 12491 pair is an ideal example to study thehydrodynamics of the early stage of a merger between two galaxy groups.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2006-01-20T20:22:37Z/2006-01-21T07:00:05Z
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 Ralph Kraft, 2007, 'Building Blocks of Large Scale Structure: A Study of a Major Merger of Two Group', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-4ydu7kj
