The XXL Survey IV. Mass-temperature relation of the bright cluster sample

M. Lieu , G. P. Smith (1) , P. A. Giles , F. Ziparo (2) , B. J. Maughan , J. Democles (3) , F. Pacaud (4) , M. Pierre (5) , C. Adami (6) , Y. M. Bahe , N. Clerc (2) , L. Chiappetti (7) , D. Eckert (8, 9) , S. Ettori (10) , S. Lavoie (11) , J. P. Le Fevre , I. G. Mccarthy , M. Kilbinger (12) , T. J. Ponman , T. Sadibekova (3) , J. P. Willis

1 UOR - University of Reading
2 MPE - Max-Planck-Institut für Extraterrestrische Physik
3 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
4 AlfA - Argelander Institute for Astronomy
5 UR EABX - Ecosystèmes aquatiques et changements globaux
6 LAM - Laboratoire d'Astrophysique de Marseille
7 INAF- Milano
8 UNIGE - Université de Genève = University of Geneva
9 INAF-IASF Milano
10 OABO - INAF - Osservatorio Astronomico di Bologna
11 Université Quebec
12 IAP - Institut d'Astrophysique de Paris

Context. The XXL Survey is the largest survey carried out by XMM-Newton. Covering an area of 50 deg(2), the survey contains similar to 450 galaxy clusters out to a redshift similar to 2 and to an X-ray flux limit of similar to 5 x 10(-1)5 erg s(-1) cm(-2). This paper is part of the first release of XXL results focussed on the bright cluster sample. Aims. We investigate the scaling relation between weak-lensing mass and X-ray temperature for the brightest clusters in XXL. The scaling relation discussed in this article is used to estimate the mass of all 100 clusters in XXL-100-GC. Methods. Based on a subsample of 38 objects that lie within the intersection of the northern XXL field and the publicly available CFHTLenS shear catalog, we derive the weak-lensing mass of each system with careful considerations of the systematics. The clusters lie at 0.1 \textless z \textless 0.6 and span a temperature range of T similar or equal to 1-5 keV. We combine our sample with an additional 58 clusters from the literature, increasing the range to T similar or equal to 1-10 keV. To date, this is the largest sample of clusters with weak-lensing mass measurements that has been used to study the mass-temperature relation. Results. The mass-temperature relation fit (M proportional to T-b) to the XXL clusters returns a slope b = 1.78(-0.32)(+0.37) and intrinsic scatter sigma(slnM\textbar T) similar or equal to 0.53; the scatter is dominated by disturbed clusters. The fit to the combined sample of 96 clusters is in tension with self-similarity, b = 1.67 +/- 0.12 and sigma(lnM vertical bar T) similar or equal to 0.41. Conclusions. Overall our results demonstrate the feasibility of ground-based weak-lensing scaling relation studies down to cool systems of similar to 1 keV temperature and highlight that the current data and samples are a limit to our statistical precision. As such we are unable to determine whether the validity of hydrostatic equilibrium is a function of halo mass. An enlarged sample of cool systems, deeper weak-lensing data, and robust modelling of the selection function will help to explore these issues further.

Domaines: Astrophysique [astro-ph]; Planète et Univers [physics]

M. Lieu, G. P. Smith, P. A. Giles, F. Ziparo, B. J. Maughan, et al.. The XXL Survey IV. Mass-temperature relation of the bright cluster sample. Astronomy and Astrophysics - A&A, 2016, 592, ⟨10.1051/0004-6361/201526883⟩. ⟨hal-01440684⟩