XMM-Newton observation of the Seyfert 1 ESO 198-G24

¹ Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany
² SRON, Sorbonnelaan 23584 CA Utrecht, The Netherlands
³ X-Ray Astronomy Group; Department of Physics and Astronomy, Leicester University, LE1 7RH, UK
⁴ LIXAM, Université Paris-Sud, 91405 Orsay Cedex, France

Corresponding author: D. Porquet, dporquet@mpe.mpg.de

Received: 20 February 2003
Accepted: 7 October 2003

Abstract

We present the results from an XMM-Newton observation (January 24, 2001) of the bright Seyfert 1 galaxy ESO 198-G24 (). We found that this Seyfert has an intrinsic 2–10 keV luminosity of about 10⁴⁴ erg s^-1. This source shows no intrinsic absorption in addition to the Galactic absorption ( cm^-2). We found both with EPIC and RGS that this source possesses significantly steeper spectra below ~1.5–2 keV than observed at higher X-ray energies, the so-called soft X-ray excess. The RGS spectra reveal no significant narrow absorption lines suggesting that if there is a warm absorber, it either has a relatively low column density, or a very high ionization parameter. The RGS data are well described by the combination of a power-law, a modified black body continuum, and weak relativistic lines of , and Ly_α. However other interpretations are not definitely excluded. The 2–10 keV energy band is well fitted by an absorbed power-law with a photon spectral index of (consistent with the typical found in Seyfert 1 galaxies). We found the presence of a narrow Gaussian emission line at 6.41 keV (i.e. <) with a moderate equivalent width of about 60–70 eV, and we found an upper limit for a broad component, if any, of 75 eV. We also found a weak absorption edge associated with cold iron with an optical depth of about 0.2.