BeppoSAX observation of Hercules A and MRC 0625-536

¹ Osservatorio Astronomico di Torino, Strada Osservatorio 20, 10025 Pino Torinese, Italy
² Istituto di Radioastronomia del CNR, Via Gobetti 101, 40129 Bologna, Italy
³ Dipartimento di Fisica Generale dell'Università, Via Pietro Giuria 1, 10125 Torino, Italy

Corresponding author: E. Trussoni, trussoni@to.astro.it

Received: 12 September 2000
Accepted: 23 November 2000

Abstract

We present BeppoSAX observations of the two FR I type radio galaxies Hercules A (3C 348) and MRC 0625-536 in the energy range 0.2-200 keV. Data analysis shows that the X-ray flux from Hercules A is consistent with a diffuse thermal plasma emitting at -5 keV with a possible, but somewhat uncertain, contribution of a softer component at keV. The non thermal emission from the active nucleus must be significantly smaller than the thermal one, and no indication of relevant core obscuration by a surrounding torus was detected. The flux from MRC 0625-536 originates from an extended region and has been fitted to a thermal law with keV and with a column density consistent with the galactic absorption. A spatially resolved spectral analysis does not show a relevant variation of the temperature and of the metallicity across the diffuse emission zone. A non thermal spectral component, related to the nuclear activity, may be present in the innermost region with some possible amount of local obscuration, contributing 10% to the total luminosity. Hard X-ray emission from MRC 0625-536 has been detected in the PDS (15-200 keV) that may be related either to its galactic core or to the intracluster region.