Confirmation of a High Magnetic Field in GRO J1008-57
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 × 10^(12)(1 + z) G, the highest among known accreting pulsars.
Additional Information
© 2014 American Astronomical Society. Received 2014 March 20; accepted 2014 July 24; published 2014 August 21. This work was supported under NASA contract No. NNG08FD60C and uses data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations team for executing the ToO observation and the Software and Calibration teams for analysis support. This research has used the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). J.W. acknowledges partial support from Deutsches Zentrum für Luftund Raumfahrt grant 50 OR 1113. Facilities: NuSTAR, Swift, SuzakuAttached Files
Published - 0004-637X_792_2_108.pdf
Submitted - 1403.5249v1.pdf
Files
Name | Size | Download all |
---|---|---|
md5:ba04456b372b87aa7df514c42fb6bdfe
|
699.2 kB | Preview Download |
md5:38476212f14feb44fdc6a8c7e3d0664f
|
613.3 kB | Preview Download |
Additional details
- Eprint ID
- 50031
- Resolver ID
- CaltechAUTHORS:20140925-112538542
- NNG08FD60C
- NASA
- 50 OR 1113
- Deutsches Zentrum für Luftund Raumfahrt (DLR)
- Created
-
2014-09-25Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- NuSTAR
- Other Numbering System Name
- Space Radiation Laboratory
- Other Numbering System Identifier
- 2014-36