English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

An XMM-Newton observation of the cool (kT=2.1 keV) cluster A1983, at z=0.044,is presented. Gas density and temperature profiles are calculated for the inner500 h_{50}^{-1} kpc (~0.35 r_200). The outer regions of the surface brightnessprofile are well described with a beta model with beta=0.74, but the centralregions require the introduction of a second component. The temperature profileis flat at the exterior with a slight dip towards the centre. The total massprofile, calculated assuming hydrostatic equilibrium, is consistent with an NFWprofile, but with a low concentration parameter c=3.75 +/- 0.74. The M/L_Bratio profile shows that, at large scale, light traces mass to a reasonableextent, and the M/L_B ratio at 0.35 r_200 is consistent with the trends withmass observed in the optical. The M_Fe/L_B ratio is about two times less thanthat observed for a cluster at 5 keV. The gas mass fraction rises rapidly tolevel off at ~200 kpc; the value at 0.35 r_200 is ~8%. The scaling propertiesof the emission measure profile are consistent with the empirical relation\mgas \propto \Tx^{1.94}, and not with the self-similar relation \mgas \propto\Tx^{1.5}. Comparison of the entropy profile of A1983 with that of the hotcluster A1413 shows that the profiles are well scaled using the empiricallydetermined relation S \propto \Tx^{0.65}, suggesting that the slope of the S-Trelation is shallower than in the self-similar model. The form of the entropyprofiles is remarkably similar, and there is no sign of a larger isentropiccore in the cooler cluster. These data provide powerful agruments againstpreheating models. In turn, there is now increasing observational support for atrend of f_gas with system mass, which may go some way towards explaining theobserved scaling behaviour. (Abridged.)Comment: Final refereed version to appear in A&A; Figs 2, 7, 11 and 12 are low  re

Entropy scaling in galaxy clusters: Insights from anXMM-Newtonobservation of the poor cluster A1983