XMM‐NewtonStudy of A3562 and Its Immediate Shapley Environs
| Autor: | Ulrich G. Briel, Jelle Kaastra, J. de Plaa, Alexis Finoguenov, Mark J. Henriksen |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal. 611:811-820 |
| ISSN: | 1538-4357 0004-637X |
| DOI: | 10.1086/422246 |
| Popis: | Using the mosaic of six XMM-Newton observations, we study the hydrodynamic state of the A3562, a cluster in the center of the Shapley Supercluster. The X-ray image reveals a sharp surface brightness gradient within the core of A3562, a 200 kpc ridge extending to the south-west. A nearby group, SC1329-313, imaged within this program also exhibits a tail aligned with the ridge. Study of the pressure and entropy identified the ridge with a 40% pressure enhancement. An associated Mach number of 1.15 relative to a polytropic sound speed for a 5 keV plasma requires the velocity of the group to be 1400 km/s, while the projected velocity difference between the cluster and the group amounts to 1200-1500 km/s. Apparent disruption of the group, if attributed to the ram pressure, also requires the velocity of the group in the cluster frame to amount to 1700+/-150 km/s. The sharp surface brightness gradient at the center is identified with a contact discontinuity, which together with dove tails in the the large-scale entropy distribution reveals a sloshing of the BCG in response to the passage of the SC1329-313 group. Using the extent of the low-entropy tails in A3562 we estimate the amplitude of sloshing motion to be 200/h_70 kpc and the oscillation frequency 1 Gyr. Comment: ApJ in press, 10 pages |
| Databáze: | OpenAIRE |
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