Author:
Adam R.,Arnaud M.,Bartalucci I.,Ade P.,André P.,Beelen A.,Benoît A.,Bideaud A.,Billot N.,Bourdin H.,Bourrion O.,Calvo M.,Catalano A.,Coiffard G.,Comis B.,D’Addabbo A.,Désert F.-X.,Doyle S.,Ferrari C.,Goupy J.,Kramer C.,Lagache G.,Leclercq S.,Macías-Pérez J.-F.,Maurogordato S.,Mauskopf P.,Mayet F.,Monfardini A.,Pajot F.,Pascale E.,Perotto L.,Pisano G.,Pointecouteau E.,Ponthieu N.,Pratt G. W.,Revéret V.,Ritacco A.,Rodriguez L.,Romero C.,Ruppin F.,Schuster K.,Sievers A.,Triqueneaux S.,Tucker C.,Zylka R.
Abstract
We propose a method to map the temperature distribution of the hot gas in galaxy clusters that uses resolved images of the thermal Sunyaev-Zel’dovich (tSZ) effect in combination with X-ray data. Application to images from the New IRAM KIDs Array (NIKA) and XMM-Newton allows us to measure and determine the spatial distribution of the gas temperature in the merging cluster MACS J0717.5+3745, at z = 0.55. Despite the complexity of the target object, we find a good morphological agreement between the temperature maps derived from X-ray spectroscopy only – using XMM-Newton (TXMM) and Chandra (TCXO) – and the new gas-mass-weighted tSZ+X-ray imaging method (TSZX). We correlate the temperatures from tSZ+X-ray imaging and those from X-ray spectroscopy alone and find that TSZX is higher than TXMM and lower than TCXO by ~ 10% in both cases. Our results are limited by uncertainties in the geometry of the cluster gas, contamination from kinetic SZ (~10%), and the absolute calibration of the tSZ map (7%). Investigation using a larger sample of clusters would help minimise these effects.
Subject
Space and Planetary Science,Astronomy and Astrophysics