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BeppoSAX detection of the Fe K line in the nearby starburst galaxy NGC 253

M. Persic·S. Mariani·M. Cappi·L. Bassani·L. Danese·A. J. Dean·G. Di Cocco·A. Franceschini·L. K. Hunt·F. Matteucci·E. Palazzi·G. G. C. Palumbo·Y. Rephaeli·P. Salucci·A. Spizzichino
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Abstract

We present BeppoSAX results on the nearby starburst galaxy NGC 253. Although extended, a large fraction of the X-ray emission comes from the nuclear region. Preliminary analysis of the LECS/MECS/PDS ~0.2-60 keV data from the central 4' region indicates that the continuum is well fitted by two thermal models: a ``soft'' component with kT ~ 0.9 keV, and a ``hard'' component with kT ~ 6 keV absorbed by a column density of ~ 1.2 x10**22 cm-2. For the first time in this object, the Fe K line at 6.7 keV is detected, with an equivalent width of ~ 300 eV. This detection, together with the shape of the 2--60 keV continuum, implies that most of the hard X-ray emission is thermal in origin, and constrains the iron abundances of this component to be ~0.25 of solar. Other lines clearly detected are Si, S and Fe L/Ne, in agreement with previous ASCA results. We discuss our results in the context of the starburst-driven galactic superwind model.

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M. Persic, S. Mariani, M. Cappi, L. Bassani, L. Danese, A. J. Dean, G. Di Cocco, A. Franceschini, L. K. Hunt, F. Matteucci, E. Palazzi, G. G. C. Palumbo, Y. Rephaeli, P. Salucci, A. Spizzichino. 1998-09-21. BeppoSAX detection of the Fe K line in the nearby starburst galaxy NGC 253. https://arxiv.org/abs/astro-ph/9809256

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