Triangulum galaxy viewed by Planck

¹ Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento, via per Arnesano, 73100 Lecce, Italy
e-mail: francesco.depaolis@le.infn.it
² INFN, Sezione di Lecce, via per Arnesano, 73100 Lecce, Italy
³ Center for Cosmology and Astrophysics, Alikhanian National Laboratory and Yerevan State University, Yerevan, Armenia
⁴ SIA, Sapienza University of Rome, 00185 Rome, Italy
⁵ LAB, CNRS UMR 5804, Université de Bordeaux, 33270 Floirac, France
⁶ School of Natural Sciences, National University of Sciences and Technology, 44000 Islamabad, Pakistan
⁷ Physik-Institut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
⁸ Department of Physics, University of Trento; and TIFPA/INFN, 38123 Povo, Trento, Italy

Received: 23 April 2016
Accepted: 11 July 2016

Abstract

We used Planck data to study the M 33 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°, and it is found to extend up to about 3° 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 M 33 galaxy and of its extended baryonic halo.