Two giant outbursts of V0332+53 observed with INTEGRAL

Journal article
(Original article)

Publication Details

Author(s): Ferrigno C, Ducci L, Bozzo E, Kretschmar P, Kühnel M, Malacaria C, Pottschmidt K, Santangelo A, Savchenko V, Wilms J
Journal: Astronomy & Astrophysics
Publisher: EDP Sciences
Publication year: 2016
Volume: 595
ISSN: 1432-0746


Context. In July 2015, the high-mass X-ray binary V0332+53 underwent a giant outburst, a decade after the previous one. V0332+53 hosts a strongly magnetized neutron star. During the 2004-2005 outburst, an anti-correlation between the centroid energy of its fundamental cyclotron resonance scattering features (CRSFs) and the X-ray luminosity was observed. Aims. The long (≈ 100 d) and bright (L ≈ 10 erg s) 2015 outburst provided the opportunity to study the unique properties of the fundamental CRSF during another outburst and to study its dependence on the X-ray luminosity. Methods. The source was observed by the INTEGRAL satellite for ~330 ks. We exploit the spectral resolution at high energies of the SPectrometer on INTEGRAL (SPI) and the Joint European X-ray Monitors to characterize its spectral properties, focusing in particular on the CRSF-luminosity dependence. We complement the data of the 2015 outburst with those collected by SPI in 2004-2005, which have so far been left unpublished. Results. We find a highly significant anti-correlation of the centroid energy of the fundamental CRSF and the 3-100 keV luminosity of E α -0.095(8)L keV. This trend is observed for both outbursts. We confirm the correlation between the width of the fundamental CRSF and the X-ray luminosity previously found in the JEM-X and IBIS dataset of the 2004-2005 outburst. By exploiting the RXTE/ASM and Swift/BAT monitoring data, we also report on the detection of a ~34 d modulation superimposed on the mean profiles and roughly consistent with the orbital period of the pulsar. We discuss possible interpretations of such variability.

FAU Authors / FAU Editors

Wilms, Jörn Prof. Dr.
Professur für Astronomie und Astrophysik

External institutions with authors

Eberhard Karls Universität Tübingen
European Space Astronomy Centre (ESAC)
University of Geneva / Université de Genève (UNIGE)
University of Maryland, Baltimore County
University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot

How to cite

Ferrigno, C., Ducci, L., Bozzo, E., Kretschmar, P., Kühnel, M., Malacaria, C.,... Wilms, J. (2016). Two giant outbursts of V0332+53 observed with INTEGRAL. Astronomy & Astrophysics, 595.

Ferrigno, Carlo, et al. "Two giant outbursts of V0332+53 observed with INTEGRAL." Astronomy & Astrophysics 595 (2016).


Last updated on 2018-21-11 at 13:50