The broad-band XMM-Newton and INTEGRAL spectra of bright type 1 Seyfert galaxies

¹ IASF-Roma/INAF, via Fosso del Cavaliere 100, 00133 Rome, Italy e-mail: francesca.panessa@iasf-roma.inaf.it
² Instituto de Física de Cantabria (CSIC-UC), Avda. de los Castros, 39005 Santander, Spain
³ IASF-Bologna/INAF, via P. Gobetti 101, 40129 Bologna, Italy
⁴ School of Physics and Astronomy, University of Southampton, SO17 1BJ Southampton, UK
⁵ INTEGRAL Science Data Centre, 1290 Versoix, Switzerland
⁶ Geneva Observatory, University of Geneva, Chemin des Maillettes 51, 1290 Sauverny, Switzerland

Received: 12 September 2007
Accepted: 22 February 2008

Abstract

Aims. The 0.5–150 keV broad-band spectra of a sample of nine bright type 1 Seyfert galaxies are analyzed here. These sources have been discovered/detected by INTEGRAL and subsequently observed with XMM-Newton for the first time with high sensitivity below 10 keV. The sample, although small, is representative of the population of type 1 AGN which are now being observed above 20 keV.

Methods. The intrinsic continuum has been modeled using three different parameterizations: a power-law model, an exponential cut-off power-law and an exponential cut-off power-law with a Compton reflection component. In each model the presence of intrinsic absorption, a soft component and emission line reprocessing features has also been tested.

Results. A simple power-law model is a statistically good description of most of the spectra presented here; an FeK line, fully and/or partial covering absorption and a soft spectral component are detected in the majority of the sample sources. The average photon index () is consistent, within errors, with the canonical spectral slope often observed in AGN although the photon index distribution peaks in our case at flat Γ (~1.5) values. For four sources, we find a significantly improved fit when the power-law is exponentially cut-off at an energy which is constrained to be below ~150 keV. The Compton reflection parameter could be estimated in only two objects of the sample and in both cases is found to be .