Temperature and total mass profiles of the A3571 cluster of galaxies

We present BeppoSAX results of a spatially resolved spectral analysis of A3571, a relaxed nearby cluster of galaxies. In the central 2 (130 h 50 kpc) radius the metal abundance is 0.49 ± 0.08 solar and the absorption (1.13±0.28)×10 atom cm, whereas elsewhere within an 8 (520 h 50 kpc) radius the abundance is 0.32±0.05 solar and the absorption consistent with the galactic value of 4.4× 10 atom cm. The significant central metal abundance enhancement is consistent with the supernova enrichment scenario. The excess absorption may be attributed to the cooling flow, whose mass flow rate is 80 ± 40 M⊙ yr −1 from our spectral fit. The BeppoSAX and ASCA radial temperature profiles agree over the entire overlapping radial range r < 25 = 1.6 h 50 Mpc. The combined BeppoSAX and ASCA temperature profile exhibits a constant value out to a radius of∼10 (650 h 50 kpc) and a significant decrease (T ∝ r, corresponding to γ = 1.28) at larger radii. These temperature data are used to derive the total mass profile. The best fit NFW dark matter density model results in a temperature profile that is not convectively stable, but the model is acceptable within the uncertainties of the data. The temperature profile is acceptably modeled with a “core” model for the dark matter density, consisting of a core radius with a constant slope at larger radii. With this model the total mass and formal 90% confidence errors within the virial radius r178 (2.5 h −1 50 Mpc) are 9.1 +3.6 −1.5 × 10 14 h 50 M⊙, by a factor of 1.4 smaller than the isothermal value. The gas mass fraction increases with radius, reaching fgas(r178) = 0.26 +0.05 −0.10 × h −3/2 50 . Assuming that the measured gas mass fraction is the lower limit to the primordial baryonic fraction gives Ωm < 0.4 at 90% confidence.