X-ray observations of the Compton-thick Seyfert 2 galaxy, NGC 5643

¹ Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy
e-mail: matt@fis.uniroma3.it
² European Space Astronomy Center of ESA, Apartado 50727, 28080 Madrid, Spain
³ ICREA and Institut de Ciéncies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franqués 1, 08028 Barcelona, Spain
⁴ Universidad Nacional Autonoma de Mexico, Apartado Postal 70-264 Ciudad Universitaria, D.F., CP 04510 México, Mexico

Received: 14 February 2013
Accepted: 10 June 2013

Abstract

We present results from a ~55 ks long XMM-Newton observation of the obscured AGN, NGC 5643, performed in July 2009. A previous, shorter (about 10 ks) XMM-Newton observation in February 2003 had left two major issues open, the nature of the hard X-ray emission (Compton-thin vs. Compton-thick) and of the soft X-ray excess (photoionized vs. collisionally ionized matter). The new observation shows that the source is Compton-thick and that the dominant contribution to the soft X-ray emission is by photoionized matter (even if it is still unclear whether collisionally ionized matter may contribute as well). We also studied three bright X-ray sources that are in the field of NGC 5643. The ULX NGC 5643 X-1 was confirmed to be very luminous, even if more than a factor 2 fainter than in 2003. We then provided the first high-quality spectrum of the cluster of galaxies Abell 3602. The last source, CXOJ143244.5-442020, is likely an unobscured AGN, possibly belonging to Abell 3602.