“GRAND UNIFICATION” in Neutron Stars Victoria Kaspi McGill University Montreal, Canada

Census of Non-Accretion Neutron Stars

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

P-Pdot Diagram Radio Pulsars: Stable Emission

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

P-Pdot Diagram SGRs, AXPs Radio Pulsars High-B Radio Pulsars

High-B Radio Pulsars: “Anomalous” X-rays? NameP (s)PdotB (G)D (kpc) J e-124.1e138.4 J e-127.4e134.9 J e-125.2e137.4 J e-135.5e139.8 J e-135.0e133.6 J e-124.8e136 J e-129.3e138.4 (RRAT)

PSR J s pulsar in SNR Kes 75 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 )

Magnetar-like Behavior in a Rotation-Powered Pulsar Gavriil et al., Science,

Chandra Observations of Kes Ng, Gavriil, VK, et al, in prep.

Timing Anomaly in PSR J Pulsar had spin-up glitch (df/f~4e-6) followed by strong spin-down Net effect: large spin-down df/f = 5e-5 Similar to that in SGR (Thompson et al. 2000); also AXP (Gavriil et al., submitted); RRAT (Lyne et al. 2009) Interesting glitch behaviour in magnetars! Livingstone, VK, Gavriil 2010 Chandra ToO Program: Look at High-B radio pulsars at glitch epochs

Change of Braking Index? Livingstone, VK, Gavriil et al., in prep.

Unification B Transition Objects (e.g. PSR J )

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 J and 1E is valid. Because, first of all, PSR J is a radio pulsar, while 1E 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? Pons et al. 2007, Aguilera et al. 2008, Pons et al 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.”

Unification: One Very Rough and Incomplete Possibility Log Age Log B Millisecond pulsars Magnetars Radio Pulsars RRATs “anti-magnetars” Isolated Neutron Stars (aka “going out on a limb”)