Details

Autor(en) / Beteiligte

• Papitto, A.
• Ferrigno, C.
• Bozzo, E.
• Rea, N.
• Pavan, L.
• Burderi, L.
• Burgay, M.
• Campana, S.
• Di Salvo, T.
• Falanga, M.
• Filipović, M. D.
• Freire, P. C. C.
• Hessels, J. W. T.
• Possenti, A.
• Ransom, S. M.
• Riggio, A.
• Romano, P.
• Sarkissian, J. M.
• Stairs, I. H.
• Stella, L.
• Torres, D. F.
• Wieringa, M. H.
• Wong, G. F.

Titel

Swings between rotation and accretion power in a binary millisecond pulsar

Ist Teil von

• Nature (London), 2013-09, Vol.501 (7468), p.517-520

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2013

Quelle

Psychology & Behavioral Sciences Collection

Beschreibungen/Notizen

• A neutron star with a low mass companion star was observed at different times as a millisecond pulsar powered either by the rotation of its magnetic field or by the accretion of mass, demonstrating the evolutionary link between these two classes of pulsars, and probing the short timescales on which the transitions between the two states may occur. Alternate power sources for a millisecond pulsar Alessandro Papitto et al . report the detection of millisecond X-ray pulsations from a neutron star thought to be accreting mass from a low-mass binary companion. The object was previously known as a radio millisecond pulsar, and within a few days of a month-long X-ray outburst, radio pulses were again detected. This demonstrates an evolutionary link between accretion and rotation-powered millisecond pulsars, and shows that some systems can swing between the two states on very short timescales. It is thought that neutron stars in low-mass binary systems can accrete matter and angular momentum from the companion star and be spun-up to millisecond rotational periods 1 , 2 , 3 . During the accretion stage, the system is called a low-mass X-ray binary, and bright X-ray emission is observed. When the rate of mass transfer decreases in the later evolutionary stages, these binaries host a radio millisecond pulsar 4 , 5 whose emission is powered by the neutron star’s rotating magnetic field 6 . This evolutionary model is supported by the detection of millisecond X-ray pulsations from several accreting neutron stars 7 , 8 and also by the evidence for a past accretion disc in a rotation-powered millisecond pulsar 9 . It has been proposed that a rotation-powered pulsar may temporarily switch on 10 , 11 , 12 during periods of low mass inflow 13 in some such systems. Only indirect evidence for this transition has hitherto been observed 14 , 15 , 16 , 17 , 18 . Here we report observations of accretion-powered, millisecond X-ray pulsations from a neutron star previously seen as a rotation-powered radio pulsar. Within a few days after a month-long X-ray outburst, radio pulses were again detected. This not only shows the evolutionary link between accretion and rotation-powered millisecond pulsars, but also that some systems can swing between the two states on very short timescales.