CONFIRMATION OF A HIGH MAGNETIC FIELD IN GRO J1008−57

Date

2014-08-21

Department

Program

Citation of Original Publication

Bellm, Eric C., Felix Fürst, Katja Pottschmidt, John A. Tomsick, Steven E. Boggs, Deepto Chakrabarty, Finn E. Christensen, et al. “Confirmation of a High Magnetic Field in GRO J1008−57.” The Astrophysical Journal 792, no. 2 (August 2014): 108. https://doi.org/10.1088/0004-637X/792/2/108.

Rights

This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain Mark 1.0

Subjects

Abstract

GRO J1008−57 is a high-mass X-ray binary for which several claims of a cyclotron resonance scattering feature near 80 keV have been reported. We use NuSTAR, Suzaku, and Swift data from its giant outburst of 2012 November to confirm the existence of the 80 keV feature and perform the most sensitive search to date for cyclotron scattering features at lower energies. We find evidence for a 78⁺³₋₂ keV line in the NuSTAR and Suzaku data at >4σ significance, confirming the detection using Suzaku alone by Yamamoto et al. A search of both the phase-averaged and phase-resolved data rules out a fundamental at lower energies with optical depth larger than 5% of the 78 keV line. These results indicate that GRO J1008−57 has a magnetic field of 6.7 × 10¹²(1 + z) G, the highest among known accreting pulsars.