2006/11/10 by Roberto Fusco-Femiano, R. Fusco‐Femiano, R. Landi +3 · 4 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Coma (optics) #Coma Cluster #Computer science #Galaxy #Galaxy cluster #Gamma-ray bursts and supernovae #Physics #Sample (material) #Software #Software package #astro-ph
paper · pdf · doi:10.1086/510739
published as Astrophys.J.654:L9-L12,2006 · 12 pages, 2 figures. Accepted for publication in ApJ Letters
arxiv created 2006/11/10 · openalex publication_date 2006/12/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The detection of a nonthermal excess in the Coma Cluster spectrum by two BeppoSAX observations analyzed with the XAS package (Fusco-Femiano et al.) has been disavowed by an analysis (Rossetti & Molendi) performed with a different software package (SAXDAS) for the extraction of the spectrum. To resolve this discrepancy we reanalyze the PDS data considering the same software used by Rossetti & Molendi. A correct selection of the data and the exclusion of contaminating sources in the background determination show that the SAXDAS analysis also reports a nonthermal excess with respect to the thermal emission at about the same confidence level of that obtained with the XAS package (~4.8 σ). In addition, we report the lack of the systematic errors investigated by Rossetti & Molendi and Nevalainen et al., taking into account the whole sample of the PDS observations off the Galactic plane, as already shown in our data analysis of Abell 2256 (Fusco-Femiano, Landi, & Orlandini). All this eliminates any ambiguity and confirms the presence of a hard tail in the spectrum of the Coma Cluster.