“GRAND UNIFICATION”in Neutron Stars

Victoria KaspiMcGill UniversityMontreal, Canada

RADIO PULSARS

Magnetars

Isolated Neutron Stars

(AXPs and SGRs)

(formerly Dim Isolated Neutron Stars – DINs)

(aka Rotation-Powered Pulsars)

“anti -magnetars”

CCOs(Central Compact Objects)

Census of Non-Accretion Neutron Stars

MILLISECOND PULSARS

RRATs(Rotating Radio Transients)

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

GPPB 2/119 )(102.3

3

24

P

PIE

P-Pdot Diagram

RadioPulsars: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 DiagramSGRs,AXPs

RadioPulsars

High-BRadioPulsars

High-B Radio Pulsars: “Anomalous” X-rays?

Name P (s) Pdot B (G) D (kpc)

J1119-6127 0.4 4.1e-12 4.1e13 8.4

J1718-3718 3.4 1.6e-12 7.4e13 4.9

J1734-3333 1.2 2.3e-12 5.2e13 7.4

J1814-1744 4.0 7.4e-13 5.5e13 9.8

J1819-1458 4.3 5.7e-13 5.0e13 3.6

J1846-0258 0.3 7.1e-12 4.8e13 6

J1847-0130 6.7 1.3e-12 9.3e13 8.4

(RRAT)

PSR J1846-0258• 0.3 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. 2008)

Magnetar-like Behavior in a Rotation-Powered

Pulsar

Gavriil et al., Science, 2008

20062000

Chandra Observations of Kes 75

2000 2006 2009Ng, 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!

Livingstone, VK, Gavriil 2010

Chandra ToO Program: Lookat High-B radio pulsars

at glitch epochs

Change of Braking Index?

Livingstone, VK, Gavriil et al., in prep.

Unification

RADIO PULSARS Magnetars

BTransition

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?

Pons et al. 2007, Aguilera et al. 2008, Pons et al. 2009

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.”

2/1

2

4

,

,8/

,

BT

B

dt

dB

BE

TAdt

dERA

eff

D

m

effeffm

eff

Unification: One Very Rough and Incomplete Possibility

Log Age

Log B

2 64 108

8

10

12

14

Millisecond pulsars

Magnetars

Radio Pulsars RRATs

“anti-magnetars”

Isolated Neutron Stars

(aka “going out on a limb”)