350 likes | 452 Views
Braking Indexes of isolated pulsars. Arxiv: 1209.2478, 1209.2273, 1211.4689 reporter:Fu, Lei. O utline. 1. Background 2. Models 3. Recent works 4. Our work. Theories Background. Braking law. magnetic dipole model.
E N D
Braking Indexes of isolated pulsars Arxiv: 1209.2478, 1209.2273, 1211.4689 reporter:Fu, Lei
Outline • 1.Background • 2.Models • 3.Recent works • 4.Our work
Theories Background Braking law • magnetic dipole model Assume:1.pure magnetic dipole model2.constant magnetic field
Observations Background • Lyne et al.(1993) • Crab B0531+21: n=2.51 • Kaspi et al.(1994) • B1509-58 : n=2.91 • Lyne et al.(1996) • Vela B0833-45 : n=1.4
models Magnetic field evolution magnetic diople radiation: B≠constant Braking law
models Disk assisted spin down • oblique rotator, non-dipole field, pulsar wind, quadrapole gravitational radiation, varying of effective moment of inertia……
Observations recent works
arxiv:1209.2478 recent works • S.-N. Zhang & Y. Xie 2012 ApJ, 757,153 • magnetic evolution
arxiv:1209.2478 recent works for young pulsars for old pulsars
Observations recent works baby pulsars
for baby pulsar younger than 2000 yr recent works • for Crab pulsar: age=957 yr(AD1054) • this model only applicable for young and old pulsars
Observations recent works
arxiv:1209.2273 recent works • J.A. Pons, D. Viganò & U. Geppert 2012 A&A 547,9 • Magnetic field evolution senarios fallback burying reemergence SN thermoelectric field generation Hall drift Ohmic decay
recent works • Thermoelectric field generation • only efficient for • <1000 yr (in standard cooling senario) • Field reemergence • accreted mass • Ohmic decay • timescale • σ depends on • dominant in and lead n> 3 • after neutrino->photon cooling(105 yr) is slow
recent works • Hall drift oscillatory modes • timescale • significant for large B field • dipole field->smaller scale • toroidal field->dipole field
recent works Hall drift oscillatory modes
recent works P0=0.01s8 pulsars2.5 kyr
recent works arXiv:1211.4689Ş. Çalişkan, U. Ertan, M. A. Alpar et al.(2012) • PSR J1734-3333 • only pulsation at radio band
recent works Disk assisted spin-down