Triangulum galaxy viewed by Planck

TL;DR

This study uses Planck data to detect temperature asymmetry in the Triangulum galaxy, revealing its differential rotation and extended baryonic halo through correlation with HI velocity data.

Contribution

First detection of temperature asymmetry in M33 correlating with its velocity field, indicating galaxy rotation and extended halo using Planck observations.

Findings

Temperature asymmetry extends up to 3 degrees from galaxy center.

Asymmetry correlates with HI velocity field within 0.5 degrees.

Evidence of differential rotation and extended baryonic halo.

Abstract

We used Planck data to study the M33 galaxy and find a substantial temperature asymmetry with respect to its minor axis projected onto the sky plane. This temperature asymmetry correlates well with the HI velocity field at 21 cm, at least within a galactocentric distance of 0.5 degree, and it is found to extend up to about 3 degrees from the galaxy center. We conclude that the revealed effect, that is, the temperature asymmetry and its extension, implies that we detected the differential rotation of the M33 galaxy and of its extended baryonic halo.