BeppoSAX/PDS identification of the true counterpart of the Piccinotti source H0917-074

¹ IASF/CNR, via Piero Gobetti 101, 40129 Bologna, Italy
² INAF/Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
³ Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA

Corresponding author: A. Malizia, malizia@bo.iasf.cnr.it

Received: 20 June 2002
Accepted: 5 August 2002

Abstract

High energy emission has been discovered serendipitously by the BeppoSAX/PDS telescope in the ~1.3° field of view around the Piccinotti source H0917-074. A re-pointing of BeppoSAX/NFI has allowed the association of this emission with the Seyfert 2 galaxy MCG-1-24-12  which lies within the original HEAO1/A2 error box of H0917-074. This is the first PDS serendipitous discovery of a Seyfert 2 galaxy and the first detection of MCG-1-24-12  in the X-ray domain. The measured 2–10 keV flux of MCG-1-24-12  is ~1 10^-11 erg cm^-2 s^-1 compatible with the Piccinotti HEAO-1/A2 observation. This is a factor of ~6 greater than that observed from EXO0917.3-0722, originally suggested as the counterpart of the Piccinotti source. The 2–10 keV spectrum of MCG-1-24-12  shows the presence of Fe K_α emission together with an absorption feature at ~8.7 keV. At high energies, the Seyfert 2 still dominates and the observed 20–100 keV flux is ~4 10^-11 erg cm^-2 s^-1.