Diagram from 1994 Magnetars, High B field Pulsars unknown!
From Kaplan (PhD 2004) This is a P-Pdot diagram and not B-P But B2 proportional to P x Pdot
Reviews There are no major reviews but try the following: • Kaspi (astroph/0402175) • Hurley (astroph/9912061) • Paczynski (1992, Acta Astronomica) • Baring (1991, A&A) The classic set of papers in this field are • Thompson & Duncan (1995, MNRAS) • Thompson & Duncan (1996, ApJ)
Giant Burst of August 1998 • Peak Luminosity of short spike, 1045 erg/s • Energy in the hard spike, 1044 erg • Total Energy radiated, 1045 erg (not including neutrinos) The luminosity exceeds LEddington
A strong B field reduces Thomson cross-section Paczynski 1992 where the cyclotron energy QED effects become important for BQED > 4.3x1013 G (electron rest mass) and photons with energy of 511 keV
Anomalous X-ray Pulsars • Periods in the range 5-20 s • No companion (either through reflex motion or as optical/IR counterpart) • Luminous X-ray sources (4U 0142+64) • But Pdot not sufficient to power LX (see Table) • Hence the name
Bursts from 1E2259+586 Kaspi
Conclusions • Soft gamma-ray repeaters and anomalous X-ray pulsars are highly magnetized neutron stars • The relationship between the two classes is unknown (is one descendent of the other?) • High B field radio pulsars (1014 G) appear to be different from magnetars. Something in the interior does care about 1014 G.
Why are magnetars of some interest? • Some have argued that the birth (hot convective core) results in a magnetar. In any case at least magnetars constitute about 10% of the birthrate. • Magnetars have been suggested to be the central sources for GRBs • Exotic QED Phenomena (Photon splitting & Vacuum Polarization; see Baring paper)