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“GRAND UNIFICATION” in Neutron Stars . Victoria Kaspi McGill University Montreal, Canada. Census of Non-Accretion Neutron Stars. Isolated Neutron Stars. ( formerly Dim Isolated Neutron Stars – DINs). CCOs (Central Compact Objects). RRATs (Rotating Radio Transients ). RADIO PULSARS.
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“GRAND UNIFICATION”inNeutron Stars Victoria Kaspi McGill University Montreal, Canada
Census of Non-Accretion Neutron Stars Isolated Neutron Stars (formerly Dim Isolated Neutron Stars – DINs) CCOs (Central Compact Objects) RRATs(Rotating Radio Transients) RADIO PULSARS (aka Rotation-Powered Pulsars) MILLISECOND PULSARS Magnetars (AXPs and SGRs) “anti-magnetars”
Why the Diversity? • Neutron stars close cousins of black holes • Gravitational redshifts of ~0.3 • WHY SO MUCH HAIR??? • Wide variety of behaviours is totally unpredicted • What could matter? • Mass • Magnetic field • Initial spin • Geometry • Composition? • Evolutionary history? John Wheeler: 1967(?) Surprised neutron stars Come with “bell and whistle”
In This Talk • Focus on finding commonalities among the various types of objects • Hopefully infer physical mechanisms behind observed behaviour • Ultimately constrain fundamental physics • Behaviour of matter at high density, low temperature • Behaviour of matter in highest magnetic fields known in Universe
Radio Pulsars(aka Rotation-Powered Pulsars) • Born hot in supernova explosions; cool slowly, thermal X-rays • Non-thermal (and some thermal) emission powered by rotation, via magnetic braking • Infer B from P, Pdot • Relativistic particle winds that produce spectacular nebulae, all rotation-powered
Radio Pulsars: Stable Emission P-Pdot Diagram
Magnetars: AXPs and SGRs • “Bad Boys”: young, volatile • Spectacular X-ray/g-ray bursts • Unusual glitches • X-ray pulsations • Lx >> spin-down luminosity • Many arguments for power via enormous B field, as inferred from spin-down
Radio Pulsars P-Pdot Diagram SGRs, AXPs High-B RadioPulsars
PSR J1846-0258 • 0.3 s pulsar in SNR Kes75 • B = 5e13 G • Youngest known: 884 yr • Bona fide rotation-powered: • Lx << Edot • Power-law X-ray spectrum • Pulsar wind nebula • Normal timing properties, including n=2.65 (Livingstone et al. 2006) • No radio emission(Archibald et al. 2008)
Magnetar-like Behavior in a Rotation-Powered Pulsar 2000 2006 Gavriil et al., Science, 2008
Chandra Observations of Kes 75 2000 2006 2009 Ng, Gavriil, VK, et al, in prep.
Timing Anomaly in PSR J1846-0258 • Pulsar had spin-up glitch (df/f~4e-6) followed by strong spin-down • Net effect: large spin-downdf/f = 5e-5 • Similar to that in SGR (Thompson et al. 2000); also AXP 0142+61(Gavriil et al., submitted);RRAT 1819-1458 (Lyne et al. 2009) • Interesting glitch behaviourin magnetars! Chandra ToO Program: Lookat High-B radio pulsars at glitch epochs Livingstone, VK, Gavriil2010
Change of Braking Index? Livingstone, VK, Gavriil et al., in prep.
Unification B Magnetars RADIO PULSARS Transition Objects (e.g. PSR J1846-0258)
Anonymous ApJ Review: Aug 12, 1999 “I believe this paper contains neither substantive new observational nor theoretical results for publication in the Astrophysical Journal… It is not clear if the analogy between PSR J1814-1744 and 1E 2259+586 is valid. Because, first of all, PSR J1814-1744 is a radio pulsar, while 1E 2259+586 is radio-quiet pulsar, without considering their X-ray properties. … There is no solid evidence that this object is similar to that of AXP…” We have come very far.
Unification? Solid line prediction of model of B-decay heating crust and subsequent cooling: B decay delays cooling; highest B NSs stay hotter longer:``magneto-thermal evolution.” Pons et al. 2007, Aguilera et al. 2008, Pons et al. 2009
Unification: One Very Rough and Incomplete Possibility (aka “going out on a limb”) Log B Magnetars 14 Isolated Neutron Stars 12 Radio Pulsars RRATs 10 “anti-magnetars” Millisecond pulsars 8 2 4 6 8 10 Log Age