Rotating baryonic dark halos

¹ Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via per Arnesano, 73100 Lecce, Italy
e-mail: dePaolis@le.infn.it
² INFN, Sezione di Lecce, Via per Arnesano, 73100 Lecce, Italy
³ Sainsbury Laboratory, University of Cambridge, Bateman Street, Cambridge CB2 1LR, UK
⁴ Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
⁵ Center for Cosmology and Astrophysics, Alikhanian National Laboratory and Yerevan State University, Yerevan, Armenia
⁶ SIA, Sapienza University of Rome, Rome, Italy
⁷ Fellow of the Pakistan Academy of Sciences, Constitution Avenue, G-5, Islamabad, Pakistan
⁸ Physik-Institut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
⁹ Department of Physics, School of Natural Sciences, National University of Sciences and Technology, Islamabad, Pakistan

Received: 16 July 2019
Accepted: 16 August 2019

Abstract

Galactic halos are of great importance for our understanding of both the dark matter nature and primordial non-Gaussianity in the perturbation spectrum, a powerful discriminant of the physical mechanisms that generated the cosmological fluctuations observed today. In this paper we analyze Planck data towards the galaxy M 104 (Sombrero) and find an asymmetry in the microwave temperature which extends up to about 1° from the galactic center. This frequency-independent asymmetry is consistent with that induced by the Doppler effect due to the galactic rotation and we find a probability of less than about 0.2% that it is due to a random fluctuation of the microwave background. In addition, Planck data indicate the relatively complex dynamics of the M 104 galactic halo, and this appears to be in agreement with previous studies. In view of our previous analysis of the dark halos of nearby galaxies, this finding confirms the efficiency of the method used in revealing and mapping the dark halos around relatively nearby edge-on galaxies.