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Title: Confirmation of a high magnetic field in GRO J1008–57

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{sub −2}{sup +3} 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{sup 12}(1 + z) G, the highest among known accreting pulsars.
Authors:
; ; ;  [1] ;  [2] ; ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9]
  1. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
  2. Center for Space Science and Technology, University of Maryland Baltimore County, Baltimore, MD 21250 (United States)
  3. Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)
  4. Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
  5. DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark)
  6. Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
  7. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
  8. Dr. Karl-Remeis-Sternwarte and ECAP, Sternwartstr. 7, D-96049 Bamberg (Germany)
  9. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
Publication Date:
OSTI Identifier:
22365124
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 792; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BINARY STARS; COSMIC X-RAY SOURCES; CYCLOTRON RESONANCE; CYCLOTRONS; DETECTION; KEV RANGE; MAGNETIC FIELDS; MASS; SCATTERING; STARS; X RADIATION