On the Dynamics of Helium in the Dilute Intracluster Medium
by
Martin Pessah(Niels Bohr International Academy)
→
Europe/Stockholm
122:026
122:026
Description
Understanding whether Helium can sediment to the core of galaxy
clusters is important for a number of problems in cosmology and
astrophysics. For example, our ignorance in the distribution of Helium
leads to systematic uncertainties in estimating the density and masses
of galaxy clusters. All current models addressing this question are
one-dimensional, and ignore the fact that the intracluster medium is a
dilute, magnetized plasma, which can effectively channel ions and
electrons, leading to anisotropic transport of momentum, heat, and
particle diffusion. This anisotropy can lead to a wide variety of
instabilities, which could be relevant for understanding the dynamics
of the heterogeneous medium. I will present the results of recent
analytical and numerical studies analyzing a wide spectrum of
instabilities, that feed off thermal and composition gradients in a
magnetized tenuous plasma, such as the ICM. I will discuss the future
prospects of studying the long term evolution of Helium sedimentation
in more realistic settings.
