Volume 550, February 2013
|Number of page(s)||18|
|Section||Stellar structure and evolution|
|Published online||17 January 2013|
Testing reflection features in 4U 1705−44 with XMM-Newton, BeppoSAX, and RXTE in the hard and soft states
Dipartimento di FisicaUniversità degli Studi di Cagliari,
SP Monserrato-Sestu, KM 0.7,
2 Dipartimento di Fisica, Università di Palermo, via Archirafi 36, 90123 Palermo, Italy
3 INAF – Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate ( LC), Italy
4 Università dell’ Insubria, via Valleggio 11, 22100 Como, Italy
5 Institut de Cieǹcies de l’Espai (IEEC-CSIC), Campus UAB, Fac. de Cieǹcies, Torre C5, parell, 2a planta, 08193 Barcelona, Spain
6 Dr. Karl Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstraße 7, 96049 Bamberg, Germany
7 INAF – Osservatorio Astronomico di Cagliari, Poggio dei Pini, Strada 54, 09012 Capoterra ( CA), Italy
8 INAF – IASF di Palermo, via Ugo La Malfa 153, 90146 Palermo, Italy
9 Institut für Astronomie und Astrophysik, Kepler Center for Astro and Particle Physics, Sand 1, 72076 Tübingen, Germany
Received: 24 May 2012
Accepted: 10 November 2012
We use data from the bright atoll source 4U 1705−44 taken with XMM-Newton, BeppoSAX, and RXTE both in the hard and in the soft state to perform a self-consistent study of the reflection component in this source. Although the data from these X-ray observatories are not simultaneous, the spectral decomposition is shown to be consistent among the different observations, when the source flux is similar. We have therefore selected observations performed at similar flux levels in the hard and soft states to study the spectral shape in these two states in a broad-band (0.1−200 keV) energy range, with good energy resolution, and using self-consistent reflection models. These reflection models provide a good fit for the X-ray spectrum both in the hard and in the soft state in the whole spectral range. We discuss the differences in the main spectral parameters we find in both states, providing evidence that the inner radius of the optically thick disk slightly recedes in the hard state.
Key words: line: formation / line: identification / stars: neutron / stars: individual: 4U 1705-44 / X-rays: binaries / X-rays: general
© ESO, 2013
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.