Submitting Campus
Prescott
Department
Physics and Astronomy
Document Type
Article
Publication/Presentation Date
3-10-2022
Abstract/Description
Accreting X-ray pulsars undergo luminous X-ray outbursts during which the luminosity-dependent spectral and timing features of the neutron star’s emission can be analyzed in detail, thus shedding light on the accretion regime at work. We took advantage of a monitoring campaign that was performed with NuSTAR, Swift/XRT, AstroSat and NICER to follow the Be/X-ray Binary 2S 1553-542 along one of its rare outbursts, and thus trace its spectral and timing evolution. We report the discovery of a luminosity-dependent cyclotron line energy for the first time in this source. The pulse profiles and pulsed fraction also show variability along the outburst, which is consistent with the interpretation that the source transitions from the subcritical to the supercritical accretion regime, separated by a critical luminosity of Lcrit ≈ 4 × 1037 erg s−1.
Publication Title
The Astrophysical Journal
DOI
10.3847/1538-4357/ac524f
Publisher
American Astronomical Society
Scholarly Commons Citation
Malacaria, C., Bhargava, Y., Coley, J. B., Ducci, L., Pradhan, P., Ballhausen, R., Fuerst, F., Islam, N., Jaisawal, G., Jenke, P., Kretschmar, P., Kreykenbohm, I., Pottschmidt, K., Sokolova-Lapa, E., Staubert, R., Wilms, J., Wilson-Hodge, C., & Wolff, M. T. (2022). Accreting on the Edge: A Luminosity-dependent Cyclotron Line in the Be/X-Ray Binary 2S 1553-542 Accompanied by Accretion Regimes Transition. The Astrophysical Journal, 927(2). 10.3847/1538-4357/ac524f
Additional Information
Please access the version-of-record published in The Astrophysical Journal here.