Planck revealed bulk motion of Centaurus A lobes

¹ Dipartimento di Matematica e Fisica “E. De Giorgi”Università del Salento, via per Arnesano, 73100 Lecce, Italy
e-mail: francesco.depaolis@le.infn.it
² INFN, Sez. di Lecce, via per Arnesano, 73100 Lecce, Italy
³ Center for Cosmology and Astrophysics, Alikhanian National Laboratory and and Yerevan State University, Yerevan, Armenia
⁴ Physik-Institut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
⁵ School of Natural Sciences, National University of Sciences and Technology, Islamabad, Pakistan
⁶ Department of Physics, University of Trento and TIFPA/INFN 38123 Povo, Trento, Italy, 38123 Povo, Italy

Received: 20 June 2015
Accepted: 20 July 2015

Abstract

Planck data towards the active galaxy Centaurus A are analyzed in the 70, 100 and 143 GHz bands. We find a temperature asymmetry of the northern radio lobe with respect to the southern one that clearly extends at least up to 5° from the Cen A center and diminishes towards the outer regions of the lobes. That transparent parameter – the temperature asymmetry – thus has to carry a principal information, i.e. indication on the line-of-sight bulk motion of the lobes, while the increase of that asymmetry at smaller radii reveals the differential dynamics of the lobes as expected at ejections from the center.