Institut für Astronomie und Astrophysik Abteilung Astronomie Sand 1, D-72076 Tübingen, Germany
Hinweis: Einige Seiten auf astro.uni-tuebingen.de können veraltet sein und werden nicht mehr aktualisiert. Note: Some webpages at astro.uni-tuebingen.de may be outdated and will no longer be updated.

Preprint D/04

Evidence for a Neutron Star in the non-pulsating massive X-ray binary 4U2206+54

J.M. Torrejón (1), I.Kreykenbohm (2,3), A. Orr (4), L. Titarchuk (5), I. Negueruela (1)

(1) Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Escuela Politenica Superior, Universidad de Alicante, Ap. 99, E-03080 Alicante, Spain
(2) Institut für Astronomie und Astrophysik - Astronomie, Sand 1, 72076 Tübingen, Germany
(3) Integral Science Data Centre, Chemin d'Ecogia 16, 1290 Versoix, Switzerland
(4) ESA/ESTEC Research and Science Support Division, Noordwijk, The Netherlands
(5) US Naval Research Laboratory, Space Science Division, 4555 Overlook Av., Washington, USA

To be published in: A&A

Abstract. We present an analysis of archival XTE and BeppoSAX data of the X-ray source 4U2206+54 . For the first time, high energy data (>30kev) are analyzed for this source. The data are well described by comptonization models in which seed photons with temperatures between 1.1kev and 1.5kev are comptonized by a hot plasma at 50kev thereby producing a hard tail which extends up to, at least, 100kev.
From temperature - luminosity arguments it is shown that the area of the soft photon source must be small (r ~ 1 km) and that the the accretion disk, if present, must be truncated very far from the compact object. Here we report on the possible existence of a cyclotron line around 30kev. The presence of a neutron star in the system is strongly favoured by the available data.

Key words: X-ray:stars - binaries - individual: 4U2206+54

astro-ph/0405182

[Home Page] [Preprints 2004] [Quick Reference] [Feedback]

| Impressum Last modified 01 Jul 2004