Seeing the halo rotation of nearby spiral galaxies using Planck data

TL;DR

This paper investigates the rotation of galactic halos in nearby spiral galaxies using Planck data, proposing a method to estimate upper limits on halo rotational velocities and exploring the role of cold gas clouds in the halos.

Contribution

It introduces a novel technique combining dynamical mass estimates and Planck data to constrain the rotational velocities of galactic halos.

Findings

Temperature asymmetry observed in galaxy halos.

Method to estimate upper limits on halo rotation velocities.

Implication of cold gas clouds in halo dynamics.

Abstract

The rotation of the galactic halos is a fascinating topic which is still waiting to be addressed. Planck data has shown the existence of a temperature asymmetry towards the halo of several nearby galaxies, such as M31, NGC 5128, M33, M81, and M82. However, the cause of this asymmetry is an open problem. A possibility to explain the observed effect relies on the presence of "cold gas clouds" populating the galactic halos, which may be the answer to the so-called missing baryon problem. Here, we present a technique to estimate an upper limit to the rotational velocity of the halo of some nearby spiral galaxies by using both their dynamical masses and the Planck data.