On the hypothesis of an advection-dominated flow in the core of NGC 1052: new constraints from a BeppoSAX observation

Abstract

We report the results of a broadband (0.1-100 keV) X-ray observation of the nearby elliptical galaxy NGC1052, performed with the BeppoSAX observatory. We confirm the presence of a bright (2-10 keV luminosity ~ 4 x 10^{42} erg/s) and strongly absorbed (NH ~ 2 x 10^{23} atoms/cm/cm) X-ray source. The flatness of the X-ray spectrum (photon index ~1.4), the estimated low accretion rate (m-dot \~ 10^{-4}) and the radio-to-X-ray spectral energy distribution suggest that this observation may represent the first direct measurement above 10 keV of an accretion-dominated flow in an elliptical galaxy.

5 Latex pages, 4 figures, Accepted for publication in Astronomy & Astrophysics Letters