Letter to the Editor
Is there a hard tail in the Coma Cluster X-ray spectrum?
Istituto di Astrofisica Spaziale e Fisica Cosmica, via Bassini 15, 20133 Milano, Italy
2 Università degli Studi di Milano, Dip. di Fisica, via Celoria 16, 20133 Milano, Italy
Corresponding author: M. Rossetti, firstname.lastname@example.org
Accepted: 17 December 2003
We report results from a re-analysis of the BeppoSAX observation of Coma and from the analysis of a second, yet unpublished observation of the same object. From our re-analysis of the first observation we find that the statistical evidence for a hard tail is about 2σ. From the analysis of the second observation which, thanks to the lower background and the longer exposure time, is characterized by a larger signal-to-noise we find no evidence for a hard tail. From the upper limit on the flux of the hard tail, using the standard Inverse Compton formulae, we derive a lower limit for the magnetic of consistent with Faraday rotation measurements.
Key words: cosmic microwave background / galaxies: clusters: individual: Coma / magnetic field / radiation mechanism: non-thermal / X-rays: galaxies: clusters
© ESO, 2004