dc.contributor.author | Dall'Osso, S. | |
dc.contributor.author | Granot, J. | |
dc.contributor.author | Piran, T. | |
dc.date.accessioned | 2012-08-08T14:00:24Z | |
dc.date.available | 2012-08-08T14:00:24Z | |
dc.date.issued | 2012-06 | |
dc.identifier.citation | Dall'Osso , S , Granot , J & Piran , T 2012 , ' Magnetic field decay in neutron stars : from soft gamma repeaters to weak-field magnetars' ' , Monthly Notices of the Royal Astronomical Society , vol. 422 , no. 4 , pp. 2878-2903 . https://doi.org/10.1111/j.1365-2966.2012.20612.x | |
dc.identifier.issn | 0035-8711 | |
dc.identifier.uri | http://hdl.handle.net/2299/8821 | |
dc.description.abstract | The recent discovery of the weak-field, old magnetar soft gamma repeater (SGR) J0418+5729, whose dipole magnetic field, Bdip, is less than 7.5 x 10(12) G, has raised perplexing questions: how can the neutron star produce SGR-like bursts with such a low magnetic field? What powers the observed X-ray emission when neither the rotational energy nor the magnetic dipole energy is sufficient? These observations, which suggest either a much larger energy reservoir or a much younger true age (or both), have renewed the interest in the evolutionary sequence of magnetars. We examine here a phenomenological model for the magnetic field decay: and compare its predictions with the observed period, P, the period derivative, , and the X-ray luminosity, LX, of magnetar candidates. We find a strong evidence for a dipole field decay on a time-scale of similar to 10(3) yr for the strongest (Bdip similar to 10(15) G) field objects, with a decay index within the range 1 =a < 2 and more likely within 1.5 less than or similar to alpha a less than or similar to 1.8. The decaying field implies a younger age than what is implied by . Surprisingly, even with the younger age, the energy released in the dipole field decay is insufficient to power the X-ray emission, suggesting the existence of a stronger internal field, Bint. Examining several models for the internal magnetic field decay, we find that it must have a very large (greater than or similar to 10(16) G) initial value. Our findings suggest two clear distinct evolutionary tracks the SGR/anomalous X-ray pulsar branch and the transient branch, with a possible third branch involving high-field radio pulsars that age into low-luminosity X-ray dim isolated neutron stars. | en |
dc.format.extent | 26 | |
dc.format.extent | 982556 | |
dc.language.iso | eng | |
dc.relation.ispartof | Monthly Notices of the Royal Astronomical Society | |
dc.title | Magnetic field decay in neutron stars : from soft gamma repeaters to weak-field magnetars' | en |
dc.contributor.institution | School of Physics, Astronomy and Mathematics | |
dc.contributor.institution | Science & Technology Research Institute | |
dc.contributor.institution | Centre for Astrophysics Research (CAR) | |
dc.description.status | Peer reviewed | |
dc.date.embargoedUntil | 2012-12-01 | |
rioxxterms.versionofrecord | 10.1111/j.1365-2966.2012.20612.x | |
rioxxterms.type | Journal Article/Review | |
herts.preservation.rarelyaccessed | true | |