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

Abstract

Context. The XXL Survey is the largest survey carried out by XMM-Newton. Covering an area of 50 deg<SUP>2</SUP>, the survey contains ~450 galaxy clusters out to a redshift ~2 and to an X-ray flux limit of ~ 5 × 10<SUP>-15</SUP> erg s<SUP>-1</SUP> cm<SUP>-2</SUP>. This paper is part of the first release of XXL results focussed on the bright cluster sample. <BR /> 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. <BR /> 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 <z< 0.6 and span a temperature range of T ≃ 1-5 keV. We combine our sample with an additional 58 clusters from the literature, increasing the range to T ≃ 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. <BR /> Results: The mass-temperature relation fit (M ∝ T<SUP>b</SUP>) to the XXL clusters returns a slope and intrinsic scatter σ<SUB>lnM|T</SUB>≃ 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 σ<SUB>lnM|T</SUB> ≃ 0.41. <BR /> Conclusions: Overall our results demonstrate the feasibility of ground-based weak-lensing scaling relation studies down to cool systems of ~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. <P />Based on observations obtained with XMM-Newton, an ESA sci- ence mission with instruments and contributions directly funded by ESA Member States and NASA. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme 089.A-0666 and LP191.A-0268.The Master catalogue is available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A2">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A2