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Survival of Cold Clouds in Hot Gas
Marcus Brüggen (University of Hamburg)
Tuesday 09/04/2019 @ 10:30, Sala IV piano Battiferro
Observations show the existence of cold (10^4K) clouds moving at fairly high velocities through hot (10^6 K) gas. Simple theory tells us that such clouds should not survive for very long. Hence it is difficult to transport cold clouds over long distances and to accelerate them to observed velocities. I will present a series of simulations that investigate the physics of cold clouds subject to various processes, such as radiative cooling, magnetic fields, thermal conduction and cosmic rays. The results confirm the difficulty of accelerating cold clouds. However, cosmic rays may play an important role in this problem.