2008/09/30 by A. Simionescu, N. Werner, Norbert Werner +5 · 150 citations
Physics and Astronomy · #Abundance (ecology) #Astrophysics #Astrophysics and Star Formation Studies #Biology #Cluster (spacecraft) #Ecology #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Lernaean Hydra #Physics #RADIUS #Stellar, planetary, and galactic studies #Supernova #astro-ph
paper · pdf · doi:10.1051/0004-6361:200810225
published in Astronomy and Astrophysics 493(2), 409-424 (EDP Sciences) · A&A, in press. Corrected right panel of Fig. 11, no other changes compared to previous version
arxiv created 2008/11/14 · openalex publication_date 2008/11/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We analyzed global properties, radial profiles, and 2D maps of the metal abundances and temperature in the cool core cluster of galaxies Hydra A using a deep ~120 ks XMM-Newton exposure. The best fit among the available spectral models is provided by a Gaussian distribution of the emission measure (gdem). We can accurately determine abundances for 7 elements in the cluster core with EPIC (O, Si, S, Ar, Ca, Fe, Ni) and 3 elements (O, Ne, Fe) with RGS. The gdem model gives lower Fe abundances than a single-temperature model. Based on this, we explain why simulations show that the best-fit Fe abundance in clusters with intermediate temperatures is overestimated. The abundance profiles for Fe, Si, S, but also O are centrally peaked. Combining the Hydra A results with 5 other clusters for which detailed chemical abundance studies are available, we find a significant decrease in O with radius, while the increase in the O/Fe ratio with radius is small within 0.1 r200, where the O abundances can be accurately determined, with d. We compare the observed abundance ratios with the mixing of various supernova type Ia and core-collapse yield models in different relative amounts. Producing the estimated O, Si, and S peaks in Hydra A requires either the amount of metals ejected by stellar winds to be 3–8 times higher than predicted by available models or the initial enrichment by core-collapse supernovae in the protocluster phase not to be as well mixed on large scales as previously thought. The temperature map shows cooler gas extending in arm-like structures towards the north and south. These structures, and especially the northern one, appear to be richer in metals than the ambient medium and spatially correlated with the large-scale radio lobes. With different sets of assumptions, we estimate the mass of cool gas, which was probably uplifted by buoyant bubbles of relativistic plasma produced by the AGN, to , and the energy associated with this uplift to erg. The best estimate of the mass of Fe uplifted together with the cool gas is , 15% of the total mass of Fe in the central 0.5′ region.