2001/01/23 by J. Nevalainen, J. Kaastra, J. S. Kaastra +6 · 1 citation
Engineering · Physics and Astronomy · #Astrophysics and Star Formation Studies #CCD and CMOS Imaging Sensors #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1051/0004-6361:20010119
Accepted for publication in Astronomy & Astrophysics
arxiv created 2001/01/23 · openalex publication_date 2001/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We present BeppoSAX results of a spatially resolved spectral analysis of A3571, a relaxed nearby cluster of galaxies. In the central 2´ (130 kpc) radius the metal abundance is solar and the absorption atom cm-2, whereas elsewhere within an 8´ (520 kpc) radius the abundance is solar and the absorption consistent with the galactic value of 4.4 1020 atom cm-2. 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 yr-1 from our spectral fit. The BeppoSAX and ASCA radial temperature profiles agree over the entire overlapping radial range 25´= 1.6 Mpc. The combined BeppoSAX and ASCA temperature profile exhibits a constant value out to a radius of ~10´(650 kpc) and a significant decrease (, corresponding to ) 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 Mpc) are , by a factor of 1.4 smaller than the isothermal value. The gas mass fraction increases with radius, reaching . Assuming that the measured gas mass fraction is the lower limit to the primordial baryonic fraction gives at 90% confidence.