GALAXY CLUSTERS WITH COOLER CORE AND FLOW OF MOLECULAR HYDROGEN

Many galaxy clusters show cooler temperature at the core than outside the core, indicating flow of cooler gases towards the centre. These cooling flows may also have association with molecular gas of hydrogen. The galaxies stream towards the centre and give rise to the formation of a central massive structure at the core which in turn throw out material from the central region as one sees in the case of the formation of galaxy group Hcg 62. In a very similar way as in the case of the galaxy groups, the ejected hot material returns to feed the centre, which is churned by the dynamics of turbulence. Here we have illustrated the example of this process occurring in galaxy cluster named Abell 1795 lying in the constellation of Bootes. This cluster exists outside the region called “Bootes Void”.

Region of Abell 1795 marked inside the white rectangle in the image below.

In Abell 1795 galaxies stream from the south towards the centre where turbulent mechanism throw out material towards the north. The thrown material bends and returns towards the centre again giving rise to a spiral galaxy cluster.

More detailed view of Abell 1795 (white rectangle in above picture) shows how galaxies stream from south towards the centre and ejected outwards from the centre towards north.

Temperature map of Abell 1795: Cooler flow towards the core. Studies from observations in X-rays by S. Ehlert et.al ,2015