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Swings between rotation and accretion power in a binary millisecond pulsar.
A Papitto1, C Ferrigno, E Bozzo
1Institute of Space Sciences (ICE; IEEC-CSIC), Campus UAB, Faculty of Science, Torre C5, Parell, 2a Planta, E-08193 Barcelona, Spain. papitto@ice.csic.es
Nature
|September 27, 2013
Summary
Neutron stars in binary systems can switch between accreting matter and emitting X-rays, and spinning via magnetic fields to produce radio pulses. This study observed a neutron star transitioning between these two states, confirming their evolutionary link.
Area of Science:
- Astrophysics
- High-energy astrophysics
- Neutron star physics
Background:
- Neutron stars in low-mass binary systems are thought to spin up to millisecond periods by accreting matter and angular momentum.
- Accretion phases are characterized by bright X-ray emission (low-mass X-ray binaries), while later stages feature radio millisecond pulsars powered by rotation.
Purpose of the Study:
- To provide direct observational evidence for the transition between accretion-powered and rotation-powered millisecond pulsars.
- To investigate the rapid state-switching capabilities of neutron star binary systems.
Main Methods:
- Observation of millisecond X-ray pulsations from a neutron star previously identified as a rotation-powered radio pulsar.
- Monitoring radio pulse detection following an X-ray outburst.
Main Results:
- Direct detection of accretion-powered, millisecond X-ray pulsations from a neutron star that was previously observed as a rotation-powered radio pulsar.
- Re-detection of radio pulses within days after a month-long X-ray outburst, indicating a rapid state change.
Conclusions:
- The observed transition provides strong evidence for the evolutionary connection between accreting low-mass X-ray binaries and rotation-powered millisecond pulsars.
- Demonstrates that some neutron star systems can rapidly switch between accretion-powered and rotation-powered states on short timescales.
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