BeppoSAX observations of Narrow-Line Seyfert 1 galaxies

II. Ionized iron features in Arakelian 564

¹ Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna, Italy
² Dipartimento di Astronomia, Università di Bologna, Via Ranzani 1, 40127 Bologna, Italy
³ Dept. of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA
⁴ Department of Astronomy, Columbia University, 538 West 120th Street, New York, NY 10027, USA
⁵ Osservatorio Astronomico di Roma, Via Frascati 33, 00044 Monteporzio-Catone, Italy
⁶ SAX-Science Data Center, Nuova Telespazio, Via Corcolle 19, 00131 Roma, Italy
⁷ Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA
⁸ XMM-Newton SOC, VILSPA - ESA, Apartado 50727, 28080 Madrid, Spain
⁹ Dipartimento di Fisica "E. Amaldi", Università degli Studi "Roma Tre", Via della Vasca Navale 84, 00146 Roma, Italy
¹⁰ Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK

Corresponding author: A. Comastri, comastri@bo.astro.it

Received: 21 July 2000
Accepted: 23 October 2000

Abstract

The BeppoSAX observations of the bright Narrow-Line Seyfert 1 galaxy Ark 564 are presented along with a high quality optical spectrum taken at the 1.5 m telescope at La Silla. The 0.1-10 keV X-ray spectrum is characterized by a strong soft component which is best described by blackbody-like emission with a temperature of ∼160 eV. At higher energies a steep ( 2.4) power-law tail is present. There is evidence of an ionized reflector in the form of an iron line and edge. We do not find significant evidence of soft X-ray features if the spectrum is modelled with a two component continuum. The optical and X-ray spectral properties support the hypothesis of a high accretion rate onto a low mass black hole.