Suzaku observations of the 2013 outburst of KS 1947+300

Date

2016-06-13

Department

Program

Citation of Original Publication

Ballhausen, Ralf, Matthias Kühnel, Katja Pottschmidt, Felix Fürst, Paul B. Hemphill, Sebastian Falkner, Amy M. Gottlieb, et al. “Suzaku Observations of the 2013 Outburst of KS 1947+300.” Astronomy & Astrophysics 591 (July 1, 2016): A65. https://doi.org/10.1051/0004-6361/201527193.

Rights

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Attribution 4.0 International (CC BY 4.0)

Subjects

Abstract

We report on the timing and spectral analysis of two Suzaku observations with different flux levels of the high-mass X-ray binary KS 1947+300 during its 2013 outburst. In agreement with simultaneous NuSTAR observations, the continuum is well described by an absorbed power law with a cutoff and an additional blackbody component. In addition, we find fluorescent emission from neutral, He-like, and even H-like iron. We determine a pulse period of ~18.8 s with the source showing a spin-up between the two observations. Both Suzaku observations show very similar behavior of the pulse profile, which is strongly energy dependent. This profile has an evolution from a profile with one peak at low energies to a profile with two peaks of different widths toward higher energies seen in both the Suzaku and NuSTAR data. Such an evolution to a more complex profile at higher energies is rarely seen in X-ray pulsars, most cases show the opposite behavior. Pulse phase-resolved spectral analysis shows a variation in the absorbing column density, NH, over pulse phase. Spectra taken during the pulse profile minima are intrinsically softer compared to the pulse phase-averaged spectrum.