2000A&A...359..509M

In the present work we report the BeppoSAX serendipitous discovery of the type 2 AGN 1SAX J2234.8-2541 in the MECS field of view when pointing at the Seyfert 2 galaxy NGC 7314. The source is optical identified with the bright (m_B=14.40) galaxy ESO 533-G50 at redshift z=0.026. The source is clearly detected at energies above 4keV but barely visible below this energy implying heavy obscuration intrinsic to the source. Spectral analysis indicates a column density of the order of 2-3x10²³cm^–2 and a power law photon index compatible with values often seen in active galaxies. These X-ray characteristics suggest a Seyfert 2 classification for 1SAX J2234.8-2541. Subsequent spectroscopy of the optical counterpart, ESO 533-G50, performed with the ESO 1.52m telescope at La Silla Observatory, confirms the type 2 nature of this source and therefore its identification with the X-ray source. We also report the marginal detection of an iron line centered at 7.29±0.47keV and having an equivalent width of 464⁺⁶³⁶_–398eV; although marginal, this result is indicative of the presence of warm material in the source. If instead the line is associated to cold material, we estimate an upper limit to its equivalent width of 290eV. The overall characteristics of 1SAX J2234.8-2541 strongly suggest that the source is Compton thin.