Magnetic field strength of a neutron-star-powered ultraluminous X-ray source
Abstract
We present the significant detection of a narrow absorption line in the Chandra spectrum of an ultraluminous X-ray source (ULX) in M51. The energy of the line, at 4.5 keV, is inconsistent with atomic absorption or features related to the instrument. The identification of several ULXs as neutron star accretors leads us to believe that this absorption line is a cyclotron resonance scattering feature (CRSF), caused by the interaction of charged particles with a strong magnetic field. Assuming scattering from electrons, the magnetic field strength implied is ~1011 G, however the line is far narrower than electron CRSFs previously observed. Scattering off more massive protons would imply a field strength of ~1015 G, a magnetar field strength. This leads to the possibility that ULXs are powered by neutron stars with extremely strong magnetic fields.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1711211B