Spinning-up: the case of the symbiotic X-ray binary 3A 1954+319
Loading...
Links to Files
Author/Creator
Author/Creator ORCID
Date
2011-11-16
Type of Work
Department
Program
Citation of Original Publication
Fuerst, Felix, Diana M. Marcu, Katja Pottschmidt, Victoria Grinberg, Joern Wilms, and Marion Cadolle Bel. “Spinning-up: The Case of the Symbiotic X-Ray Binary 3A 1954+319.” In Proceedings of 8th INTEGRAL Workshop “The Restless Gamma-Ray Universe” — PoS(INTEGRAL 2010), 115:017. SISSA Medialab, 2011. https://doi.org/10.22323/1.115.0017.
Rights
This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Attribution-NonCommercial-ShareAlike 1.0 Generic (CC BY-NC-SA 1.0)
Attribution-NonCommercial-ShareAlike 1.0 Generic (CC BY-NC-SA 1.0)
Subjects
Abstract
We present a timing and spectral analysis of the variable X-ray source 3A 1954+319. Our analysis
is mainly based on an outburst serendipitously observed during INTEGRAL Key Program observations of the Cygnus region in 2008 fall and on the Swift/BAT longterm light curve. Previous
observations, though sparse, have identified the source to be one of only nine known symbiotic
X-ray binaries, i.e., systems composed of an accreting neutron star orbiting in a highly inhomogeneous medium around an M-giant companion. The spectrum of 3A 1954+319 above 20 keV can
be best described by a broken power law model. The extremely long pulse period of ∼5.3 hours
is clearly visible in the INTEGRAL/ISGRI light curve and confirmed through an epoch folding period search. Furthermore, the light curve allows us to determine a very strong spin up of
−2×10⁴ h/h during the outburst. This spin up is confirmed by the pulse period evolution calculated
from Swift/BAT data. The Swift/BAT data also show a long spin-down trend prior to the 2008
outburst, which is confirmed in archival INTEGRAL/ISGRI data. We discuss possible accretion
models and geometries allowing for the transfer of such large amounts of angular momentum and
investigate the harder spectrum of this outburst compared to previously published results.