Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-06-21
Astronomy and Astrophysics
Astrophysics
10 pages, 5 figures, accepted for publication in the Astrophysical Journal, higher resolution version at http://visav.phys.uvi
Scientific paper
10.1086/521383
The rich cluster Abell 520 (z=0.201) exhibits truly extreme and puzzling multi-wavelength characteristics. It may best be described as a "cosmic train wreck." It is a major merger showing abundant evidence for ram pressure stripping, with a clear offset in the gas distribution compared to the galaxies (as in the bullet cluster 1E 0657-558). However, the most striking feature is a massive dark core (721 h_70 M_sun/L_sun) in our weak lensing mass reconstruction. The core coincides with the central X-ray emission peak, but is largely devoid of galaxies. An unusually low mass to light ratio region lies 500 kpc to the east, and coincides with a shock feature visible in radio observations of the cluster. Although a displacement between the X-ray gas and the galaxy/dark matter distributions may be expected in a merger, a mass peak without galaxies cannot be easily explained within the current collisionless dark matter paradigm. Interestingly, the integrated gas mass fraction (~0.15), mass-to-light ratio (220 h_70 M_sun/L_sun), and position on the X-ray luminosity-temperature and mass-temperature relations are unremarkable. Thus gross properties and scaling relations are not always useful indicators of the dynamical state of clusters.
Babul Arif
Balam David D.
Capak Peter
Hoekstra Henk
Mahdavi Andisheh
No associations
LandOfFree
A Dark Core in Abell 520 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Dark Core in Abell 520, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Dark Core in Abell 520 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-192208