Day 7416: 2 ,303 Years of SN1987A

Patrice BouchetCEA/DSM/Sap

Saclay

How old were How old were you when this you when this issue appeared?

issue appeared?

ADS: ~2826 (~2.7/week) refereed papers (since 1987)

(in 45 minutes???)

O

Heating releases a few nucleons

e-+ p → e + n

Escaping e carry off energy and lepton number e scatter through charged + neutral current (mean free path < ~1m at the center!): Initially the SW has enough energy .. BUT: • as it travels, it heats and melts Fe (loss of ~8 MeV/nucleon)• neutrino emission is accelerated another energy loss

The energy released by further collapse is trapped

GM2/2R ~ 2.5 1053 ergs (M=1.4Mo; R=10km)

Summed losses ≡ initial energy carried by SW

r

5 x 109 K1011g/cm3

3x1014g/cm3

t = 10ms

Gain (Heating) Region

M

L

L

L

L

Shock

Shock

Shock

Sho

ck

M

M

M

• t~0.01s the shock stalls at R~200-300km (~equilibrium)

• t >0.5s neutrino heating of the nucleon “soup” left in the wake of the shock revives the SW (T~2 MeV + very high entropy): Energy is IN THE RADIATION, NOT IN THE MATTER

• The pressure exerted by this gas pushes the shock outward: 99% of the 1099% of the 105353 ergs ergs released in the collapse is radiated in υ of all flavours

• t(leak out) ~3s

DELAYED MECHANISMSMezzacappa et al., 1995, 2000 Mezzacappa et al., 1995, 2000

Burrows et al., 1995Burrows et al., 1995

Convective/SASI Unstable

Cooling Region

Gain radiusGain radius

Chronology

• Collapse Core bounce proto-NS NS ~1 s ~10 ms ~0.5 s

• g/cm3: 1010 1011 1012 1013 1014

~100 ms ~25 ms ~5 ms ~1 ms

• t ~ 1 min shock crossed He (R~ 500 x 103 km)• Reverse shock forms• t ~ 3h: shock emerges: flash UV ionisation• Envelope expands cools (14000 K to 6000K)

• Temperature: ~ 4±1 MeV• Decay time: ~ 4.5 s

Just about right for neutron star formation; results close to modern theory

Neutrinos

• Most of them Most of them ννee

• Fluence at Earth 5.0Fluence at Earth 5.0±2.5 x 10±2.5 x 1099 cm cm-2-2

• Core radius = 30Core radius = 30±20 km±20 km• Total Total ννee Energy: ~ 4±1 x 10Energy: ~ 4±1 x 1052 52 ergs ergs

• TotalTotal νν Energy: ~ 3±1 x 10Energy: ~ 3±1 x 105353 ergs ergs• MMBaryonBaryon = 1.45±0.15 M = 1.45±0.15 Mo;o;

• MMGravitGravit.= 1.35±0.15 M.= 1.35±0.15 Moo

~1 nanogram of ν through IMB and KII and only 1 in 1015 were captured ~500 grams through the entire Earth ≡ 15MegaT of TNT (1 million people (1 million people experienced 1 SN1987A experienced 1 SN1987A ννee event in their body and ~300 experienced 2 event in their body and ~300 experienced 2

events)events)

¯

¯

Mont Blanc (LSD) ~4.7 hours earlier?Mont Blanc (LSD) ~4.7 hours earlier?2-stage explosion in a rapidly rotating 2-stage explosion in a rapidly rotating collapsar could explain the difference collapsar could explain the difference between LSD/IMB-KII between LSD/IMB-KII υυ detectionsdetections (Imshennik & Ryazhskaya, 2003)(Imshennik & Ryazhskaya, 2003)

Distant echoes: interstellar clouds (P. Tisserand: ~1200 real EROS2 images from july 1996 to feb. 2002)

Nearby echoes: Napoleon’s Hat etc. few solar masses ejected by progenitor

10 Ly

Light Echoes• R310, R430; W700, S730, N980; R1170 complex (5 echoes); SE3140, N3240

• 3-dimensional structure (Xu et al., 1995).(Xu et al., 1995).

Rings are not matter but a geometrical effect

l.yr

The Progenitor Star ?• Why blue giant, not red giant?Why blue giant, not red giant?1.1. Low metallicityLow metallicity ((Shklovskii, 1984Shklovskii, 1984; Arnett, 1987; Hillebrandt et al., 1987): ; Arnett, 1987; Hillebrandt et al., 1987): Ni rich shell?Ni rich shell?2.2. Mass lossMass loss ((Maeder & Lequeux, 1982Maeder & Lequeux, 1982; Maeder, 1987): ; Maeder, 1987): light curve and slow V ejecta?light curve and slow V ejecta?3.3. Blue LoopsBlue Loops ( (Summa & Chiosi, 1970Summa & Chiosi, 1970): ): must have been RSGmust have been RSG (Woosley, 1988) (Woosley, 1988)• Mixing: 56Ni up to ~3000 kms-1, H down to ~500 kms-1?Mixing: 56Ni up to ~3000 kms-1, H down to ~500 kms-1?1.1. Convective mixing induced by rotationConvective mixing induced by rotation (Weiss et al., 1988)(Weiss et al., 1988)2.2. semi-convection at low abundance of heavy elementssemi-convection at low abundance of heavy elements (Woosley et al., 1988)(Woosley et al., 1988)3.3. evolutionary effect in a close binary systemevolutionary effect in a close binary system (Podsiadlowski & Joss, 1989)(Podsiadlowski & Joss, 1989)

• Menvelope = 18±1.5 Mo

• MHe = 6 ± 1 Mo, MH,Envelope = 5-10 Mo

• MFe = 1.45 ± 0.15 Mo

• MNS = 1.40 ± 0.15 Mo (2-3 1053 ergs)• Heavy Elements ejected = 1.5 ± 0.5 Mo (≤1500kms-1)

Mpre-SN = (19.4 ± 1.7) Mo

Sk -69°202: B3 Ia; Teff = 16300 K; R = 46.8Ro

NTT / Wampler et al., 1990 new constraints! (at least rotational effects & convective mixing)

First Observations• Precursor too massive for a “good” explosion mechanism• No spherical symmetry (polarimetry)• Strong mixing (Bochum event)

1. R-T instabilities: mix the C, O, He layers when the outgoing shock front passes through, but cannot accountcannot account for the high velocity of Ni (~3100km/s) (Kifonidis et al., 2000), nor the observed polarization.

2. Convection: size and scale too small to explain asymmetries + NO EFFECT ON NEUTRINO HEATING and shock NO EFFECT ON NEUTRINO HEATING and shock evolutionevolution (Bruenn & Mezzacappa, 1994)

3. Rapid & differential rotation of progenitor (Steinmetz & Höflich, 1992): explains polarization because of blue SGblue SG

4. Rotation of the collapsing core: introduces axial symmetry but weak effectweak effect on the explosion (Zwerger & Müller, 1997).

5. Magnetic fields + rotation 2 high-density supersonic jets from the collapsed core too strong B and jets must stop after <3s (Khokhlov & Höflich, 2000)

Utrobin, 2007Utrobin, 2007

• Single star models:Single star models: 1.1. How massive?How massive? (Utrobin 2005) (Utrobin 2005)2.2. Rotation tends to suppress the blue solution by increasing the He core mass, Rotation tends to suppress the blue solution by increasing the He core mass,

but seems necessary to break spherical symmetry prior to the explosion but seems necessary to break spherical symmetry prior to the explosion (Woosley et al., 1997)(Woosley et al., 1997)

3.3. LBV?LBV? (Smith, 2007) (Smith, 2007)• Binary star?Binary star? (Podsiadlowski, 1992, Morris & Podsiadlowski, 2006)(Podsiadlowski, 1992, Morris & Podsiadlowski, 2006)

HYDRODYNAMIC MODELUtrobin, 2007Utrobin, 2007

Woosley, 1997Woosley, 1997

Utrobin & Chugai, 2005Utrobin & Chugai, 2005

No 56Ni

VNiMax= 2500km s-1

VNiMax= 4000km s-1

VNiMin= 900km s-1

No 56Ni

VNiMax= 2500km s-1

VNiMin= 960km s-1

E=1.0 x 1051 erg

ii

E=1.5 x 1051 erg

ii

Need of both photometry and spectroscopyNeed of both photometry and spectroscopy

Light Curve Evolution

Envelope transparent (in

the optical)

Release of trapped radiation

H rec.

He rec.

Radioactive decay

• Shock through the surface, 3.84h after neutrinos: T~3x10Shock through the surface, 3.84h after neutrinos: T~3x1055 K K UV flash UV flash ~3h, R X 10 ~3h, R X 10 V ~ V ~ 6.46.4

• As envelope expands it flows through a recombination frontAs envelope expands it flows through a recombination front: Radiation : Radiation doesn’t diffuse to photosphere but photosphere moves to radiation;doesn’t diffuse to photosphere but photosphere moves to radiation;

energy is released BY recombination but comes from the SHOCKenergy is released BY recombination but comes from the SHOCK

• After H, He recombination releases energy (shock, After H, He recombination releases energy (shock, recombination itself, and radioactivity that had recombination itself, and radioactivity that had diffused out while “awaiting” the recombination front.)diffused out while “awaiting” the recombination front.)• Radioactive energy deposition comes from Compton scattering of γ-ray lines (56Co 847, 1238 keV)

Recombination wave

Radioactive tail 56Co

Dust Formation

iiiFreeze-out phase+ Radioactive tail

Radioactive tail 44Ti

Ring emission

Ejecta emission

iiiExpanding

Photosphere

Snuc = M(56Ni) x [3.9 x 1010 e-t/τ(Ni) + 7.2 x 109 (e-t/τ(Co) – e-t/τ(Ni)) erg g-1 s-1

SAAOESO, CTIO

FREEZE-OUTThe recombination & cooling time scales become comparable with the expansion time scale: conversion of energy in radiation is not instantaneous any longer emitted luminosity remains greater than instantaneous radioactive power deposition (Fransson & (Fransson & Kozma, 1993)Kozma, 1993)

56Co / 57Co = 2

X = 2 x 1037 erg s-1

P = 5 x 1037 erg s-1

56Co

Bouchet et al., 1996

UVOIR BLC

57Co

44Ti

22Na

Total Input

e+ iObserved Bolom.

luminosity

The Dust

Bouchet & Danziger, 1993Bouchet & Danziger, 1993

Lucy, Danziger, Gouiffes & Bouchet, 1989, 1991Lucy, Danziger, Gouiffes & Bouchet, 1989, 1991

IAUC4746 March 1, 1989

• Clumps• Silicates?

Ejecta emission = “Hot” dust• Dust still present at day 6067 (Bouchet et al., 2004)(Bouchet et al., 2004)• And at day 7241 (Bouchet et al., 2006, 2007)

• 90 K < TDust,Ejecta < 100 K

• MDust,Ejecta = 0.1-2 x 10-3 Mo

• LIR = (1.5±0.5) x 1036 ergs-1

T-ReCS/Gemini-SouthN: 10.36μm (Δ=5.30μm)

Fν = 0.3±0.1 mJy! Fν = 0.45±0.05 mJy!

Oct. 20,2003 Dec. 26, 2006

Flux increase Flux increase due to heating due to heating

by Reverse by Reverse Shock?Shock?

Inner Debris• Glowing: 44Ti decay• Interior dust clouds• Cold! < 300 K• Stirred, not blended

•Fe bubbles: ~1% of mass, ~50% of interior volume

:

Why don’t we see a compact object?Why don’t we see a compact object?• Optical, near IR: obscured by black cloud? • X-rays: < cooling neutron star. Debris may be opaque at 1 keV. • Absorbed luminosity should emerge as far IR.

Axisymmetric ejecta: Wang et al., 2002

56NiRed

ShiftedBlue

ShiftedNonrelativistic Jets-induced explosion

Radioactive elements at t=250s

He, O, CaSynthesized in progenitor

HST, Jan. 2007 - SAINTS

Circumstellar Structure

Martin & Arnett, 1995

(Michael et al. 2003)

“Standard” Model• RSG outer envelope BSG •Gas expulsed by slow RSG wind (550kms-1) concentrated into dense equatorial plane• High-velocity low-density isotropic BSG wind for final ~20 000 yr• Faster BSG wind overtook RSG wind • BSG photoionizes and heats gaz from RSG wind (Chevalier & Dwarkadas 1996)

Radius: R ~ 0.6 lt yr

Expanding: V ~ 10 km s-1

Density ~ 3 x 103 – 3 x 104 cm-3

Glowing mass ~ 0.1 MSun

Nitrogen-rich

Triple Ring system

• Single rotating star: hydrodynamic formation due to ionization and heating of the cool RSG wind (Meyer, 1997, 1999)• Binary system: impulsive mass loss from primary star, formation of a thin dense shell, and the expansion of 2 jets (Soker, 2002)• Binary mergers: mass loss from a rotationally distorted envelope following rapid in-spiral of a companion inside a common envelope (Podsiadlowski, 1992; Morris & Podsiadlowski, 2006)• LBV: unstable LBV eject and shape their nebulae when BSG (Smith, 2007)

Why three rings? Why three rings? Rotation needed for the equatorial plane, and RSG are too big Rotation needed for the equatorial plane, and RSG are too big Podsiadlowski BUT Woosley, Chevalier, Dwarkadas, etc… Podsiadlowski BUT Woosley, Chevalier, Dwarkadas, etc…

Morris & Podsiadlowski, 2006 (Document STSCI)

N. Smith

LBV: HD168625

PN: MYCN18 (HST/WFPC2)

The Reverse Shock

Michael et al., 2003

• High velocity debris cross the RS at v~ 12 x 103 kms-1

• Freely streaming H atoms in the RS ~ 8000 kms-1

• Post-shock ions = 2000 kms-1

Fast atoms & Slow ionsFast atoms & Slow ions

Resonant scattering:

Lyα↑

Lyα↓

Emission from the Reverse ShockHeng et al., 2007; Smith et al., 2005

McKee, 1974: Expanding debris are decelerated by the CSM which causes a shock to propagate inward through the SN material (+ Chevalier, 1982)

Collisional excitation of neutral H Collisional excitation of neutral H from the debris crossing the RSfrom the debris crossing the RS radiative shock seen as very radiative shock seen as very

broad, high-vel Lybroad, high-vel Lyαα & H & Hαα emission emission

Extinction by dust in the ring

• No cylindrical symmetry

The “Bleach Out” of the Reverse Shock

•At t=18 yr, Lα from RS ~ 15Lo ≈ 2.3 x 10-3 Mo yr-1 (x 4 since 1997)(x 4 since 1997)

Smith et al., 2005

• LLαα continuum from gas continuum from gas

shocked by the forward blast shocked by the forward blast wave ionizes neutral H in the wave ionizes neutral H in the debris before they reach the debris before they reach the RS: RS: when the inward flux of when the inward flux of ionizing photons exceeds the ionizing photons exceeds the flux of H approaching the RS flux of H approaching the RS

Preionization shuts off Preionization shuts off the RS emissionthe RS emission

Hotspots!

2006 – 2003 difference

• Ring has brightened by factor ~ 3Ring has brightened by factor ~ 3• Hotspots still unresolvedHotspots still unresolved• Have not fully merged Have not fully merged • Are the last spots in denser regions Are the last spots in denser regions than the ones where the first spots than the ones where the first spots appeared?appeared?

What caused fingers?What caused fingers?Why so regularly spaced?Why so regularly spaced?

Pun et al., 2002

Unfolding the ring! (Garnevich, 2006)

1994

2007

Challis, 2007

ACIS Images 2000–2007

Ring-like

Asymmetric intensity

Developments of X-ray spots

becoming a complete ring

as the blast wave crosses the

inner ring

Surface brightness increases

Now ~x18 brighter than 2000

Lx (0.5-2keV) = 2.1x1036 ergs/s

No point source at centerNo point source at center

E

N

1 arcsec

Park, 2007

X-ray Imaging

N

E 1991

ROSAT/HRI (5” pixels)

HEASARC/SkyView

1 arcsecond

ACIS (1999-10): Burrows et al. 2000

Green-Blue: ACIS

Red: HST

Contour: ATCA

Park, 2007

Prompt Phase• Burst of emission seen by MOST on day 2; peaked on day 4 (Turtle et al. 1987)• Power law decay, faded by day 150 • Synchrotron in BSG wind (ρ r –2) (Storey & Manchester 1987; Chevalier & Fransson 1987)

Ball et al. 1995Ball et al. 1995

Late Phase (Gaensler, 2007) • after ~3 yr: impact with dense RSG wind• α ~ -0.9 optically thin synchrotron emission, steep electron density and small compression ratio in the shock (vs. ~ -0.5)• Consistent multi-wavelength picture of reverse-shock emitting region: interaction is with dense gas in equatorial plane• Radio-source same size as optical ringRadio-source same size as optical ring

RADIO EMISSION

Manchester et al., 2002Manchester et al., 2002

ATCA 9 GHz super-resolved (0.5 arcsec)

Radio Imaging

• Limb brightened

• Bright lobes to east and west

• Eastern lobe brighter than western lobe, & brightening faster

Same as X-raysSame as X-rays

ATCA 9 GHz diffraction limited (0.9 arcsec)

Gaensler, Gaensler, 20072007

X-Ray Light Curves Chandra

(0.5 – 2 keV)

Chandra

(3 – 10 keV)

ATCA

ROSAT

Similar rates of hard X-ray and radio

The same origin for them?

due to softening of X-ray spectrum?

Image: ACIS 0.4-0.5 keVImage: ACIS 3-8 keVImage: ACIS 3-8 keV

Contours: ATCA 9GHzContours: ATCA 9GHz

X-r

ay

Flu

x (1

0-13

erg

s/cm

2 /s)

X-r

ay F

lux (

10

-13 e

rgs/

cm2/s

) 0.5-2 keV

3-10 keV

ROSAT

(Hasinger et al. 1996) Chand

ra/A

CIS

X-ray (2005-7) vs. Optical (2005-4)

d ~

620

0

Image: ACIS 0.5-2 keV

Contours: HST (Peter Challis)

Forward shock enters a “wall”?Forward shock enters a “wall”?

X-rays: (Park et al., 2004, 2006)

Radio: Gaensler & Staveley-Smith

PHYSICAL INTERPRETATION

Low speed oblique radiative shock: optical/UV

High speed shock: radio, hard X-ray

Eli Michael/Colorado

Slower shock in high-density knot: soft X-rays

Park et al., 2002, 2004; Zhekov et al., 2005 2-shocks modelAt t = 18 yr:1. Soft X-Ray = Decelerated, slow (300-1700 kms-1); kT=0.51keV; ne~6300 cm-3

2. Hard X-Ray = High-speed (3700±900 kms-1); kT= 2.7 keV; ne ~ 280 cm-3

T-ReCS (day 6526)

Spitzer (day 6190)Spitzer (day 6190)

GraphiteCarbon

Silicates

Thermal emission from shock-heated silicate dust

T6067 = (180±15) K

M6067= (0.1-1) x 10-5 Mo

T6526 = (160±15) K

M6526 = (3 ±1) x 10-6 Mo

MID-IR EmissionMID-IR Emission11.7μm 18.3μm

Temperature Optical Depth

Bouchet et al., 2006

Dust Heating MechanismDust Heating MechanismT-ReCS/HST

What heats the dust?What heats the dust?1. Collisional heating?2. Radiative heating?

Where is the dust?Where is the dust?1.1. In the X-ray emitting gas?In the X-ray emitting gas?2.2. In the denser UVO emitting knots?In the denser UVO emitting knots?

Dust severely depleted in the shocked gas:1.1. Grain destruction by the SN shock wave?Grain destruction by the SN shock wave?2.2. Inefficient production in the progenitor? Inefficient production in the progenitor?

IR-to-X ray flux ratio IRX ≈ 1! (Tgas ≈ 2x107 K IRX ≈ 100)

(Dwek, 1987)

ACIS/11.7m ACIS/18.3m

ATNF/11.7m ATNF/18.3m

SPITZER, 2007SPITZER, 2007:

ATCA / Chandra / HST (day 6300)

HSTHST/11.7/11.7μμm m (day 6526)(day 6526)

HSTHST/18.6/18.6μμm m (day 6526)(day 6526)

Physical Picture

Cf. Michael et al. 1998Cf. Michael et al. 1998

EQUATORIAL RING

HOT FINGERS

SHOCK WAVE

HOT GAS

REVERSE SW

COOL EJECTA

NS/BH?

Optical/Soft X-raysOptical/Soft X-rays

IR??IR??

Hard X-rays

RadioRadio

11.7μm (Bouchet et al., 2006)(Bouchet et al., 2006) and HST (Challis, 2006(Challis, 2006)

SAINTS (F250W)SAINTS (F250W)

McCray, 2007McCray, 2007

SN 1987A at 20 Years- HST images: optical spots dominate entire inner ring; blast wave crosses ER- Inner ring detected in the mid-IR at day 6067: shock-heated silicate dust- Dust still present in the ejecta at day 7241: heated by RS? Reverse shock approaches the central debris (?) - Soft X-ray, mid-IR & radio images resemble optical image: origin mid-IR?- Ratio [hard (> 3keV) X-rays/radio] ~ Cst.- Soft (~0.5 – 2 keV) X-rays increased rapidly after hotspots appeared; dominated by the decelerated shock since day ~6000; l.c. makes a turn-up at day ~6200 as ring mid-IR flux at day ~6000- X-ray radial expansion rate reduces since day ~6200, shock velocityshock velocity reduces

to 1400 km/s; radio expansion constant at ~ 4700 km/s (Rradio = Roptical)

mid-IR vs HST (2005-1)

Hα=red; OIII=green; F250W=blue

HST - SAINTS

• Explosion mechanism and progenitor??

(Bouchet et al. 2006).(Bouchet et al. 2006).

Why No Pulsar Detection NOW?• Possible that neutron star has accreted matter and turned into a black hole?: 5656Co which powered the l.c. shows that very little Co which powered the l.c. shows that very little mass could have fallen back mass could have fallen back ++ BH truncates a gradually decreasing BH truncates a gradually decreasing flux of neutrinos + doesn’t produce burstsflux of neutrinos + doesn’t produce bursts (Woosley, 1988)(Woosley, 1988)

• Maybe not beamed toward us - if slowish pulsar, expected beaming fraction ~ 0.2 (Manchester, 2006)(Manchester, 2006)

• PossiblyPossibly obscured by dust obscured by dust

• Pulsar magnetic field may take time to develop

• A slow, low E pulsar would not pulse at optical or X-ray wavelengths (except maybe thermal emission from NS surface)

• Although outer parts of nebula probably have low optical depth, we really know very little about conditions right in centre - could be absorption/scattering of radio pulses

.

Keep searching for a radio pulsar and point X-ray source!

“New” Pulsar Detection ?• Several detections during 1992 – 1996 at different frequencies• Power faded after 1993; last detected 1996• Emission with a complex period modulation near 2.14 ms• Frequency of the signals followed a consistent and predictable

spin-down [~(2-3) x 10-10 Hz s-1] over the several year • Modulation of the 2.14 ms period with a ~1000 s period, which

complicates its detection• Precession due to deformation or crustal density distribution

not symmetric about the axis of rotation

Middleditch et al., 2000:

Santostasi, Johnson, & Frank, 2003:• possible asymmetric deformation that causes the precession• main mechanism for the loss of rotational energy due to emission of gravitational radiation

Continuous source of gravitational wave detectable Continuous source of gravitational wave detectable with LIGO II in a few days (10with LIGO II in a few days (1066 years for LIGO I): years for LIGO I): 20132013

Forecasting SN1987A2017 celebration:2017 celebration:

• X-ray, optical ring: ~ 10 x brighter than todayX-ray, optical ring: ~ 10 x brighter than today• Hotspots will mergeHotspots will merge

• Reverse shock emission will vanishReverse shock emission will vanish• Interior debris will begin to brightenInterior debris will begin to brighten

• Circumstellar matter will begin to glowCircumstellar matter will begin to glow• Spectacular images of NT radio emission Spectacular images of NT radio emission

from ALMAfrom ALMA• Compact Object: JWST?, ALMA?Compact Object: JWST?, ALMA?• Gravitational waves from LIGO II?Gravitational waves from LIGO II?

( based on McCray, 2007)( based on McCray, 2007)

NACO 2007

Forecasting SN1987A

2027 celebration2027 celebration::

•X-rays, optical: ~ 100 x brighter than todayX-rays, optical: ~ 100 x brighter than today•Will clearly see interior debris and circumstellar matterWill clearly see interior debris and circumstellar matter

•Newly synthesized elements will begin to cross reverse shockNewly synthesized elements will begin to cross reverse shock• + ???? + ????

ARE WE REALLY MADE FROM THE

ASHES OF STELLAR DEATH?

How/Why Could a Star Explode?• Direct Hydrodynamic: always fails? (works for <15Mo + soft EOS)• Nuclear-burning aided? (Mezzacappa et al. 2006)• Neutrino-Driven Wind, spherical 1D (Burrows 1987): Lowest-mass massive stars (O/Ne/Mg cores; 8.8 Mo, Kitaura et al. 2006)• Convective/SASI (Spherical Accretion Shock Instability) Neutrino-Driven Wind 2D (Blondin et al. 2003) might work for 11.2 Mo of WHW2002, (Buras et al. 2006): other progenitor problematic • Acoustic Power Mechanism: after delay, all progenitors explode (Burrows et al. 2006,2007); High entropies favor r-process• Magnetic fields, neutrino mixing and realistic neutrino transport (Mezzacappa et al. 2006)• MHD Jet Explosions: Rapid rotation necessary (e.g., Burrows et al. 2007b) works for Hypernovae and GRB

The Key feature of almost all mechanisms is The Key feature of almost all mechanisms is the Breaking of Spherical Symmetry the Breaking of Spherical Symmetry 3D 3D

Radial Expansion

rapid deceleration in X whilst ~ constant in radio+ Discrepancy in radius between radio and X-rays

???

X-Rays

Radio

4700 ± 100 kms-1

~ 35 000 kms-1

t<5000d: 3600km/s

t>5000d: 4700km/s

Racusin et al. 2007 Gaensler et al., 2007

MAGNETIC FIELDMAGNETIC FIELD Radio and hard X-rays come from relatively low Radio and hard X-rays come from relatively low density gas between blast wave and reverse shockdensity gas between blast wave and reverse shock

How (where) are relativistic electrons accelerated?How (where) are relativistic electrons accelerated?

Non linear kinetic theory of Cosmic Ray:Non linear kinetic theory of Cosmic Ray: shock modification and strong magnetic field shock modification and strong magnetic field amplification in ALL the young SNRamplification in ALL the young SNR (Berezhko, 2005; (Berezhko, 2005; Berezhko & Ksenofontov, Berezhko & Ksenofontov, 2000, 20062000, 2006 ) )

Radioemission spectrum• Considerable synchrotron cooling of high energy e- which reduces their X-ray synchrotron flux • Expected γ-ray energy flux at TeV-energies ~ 2 x 10-13 erg cm-2s-1

G-SNRs source population of the G-CRG-SNRs source population of the G-CR

Limits on Properties of a Central Pulsar• No evidence for central source (PWN or pulsar) at any wavelength: optical luminosity limit ~8 x 1033 erg s-1 (Graves et al. 2005)(Graves et al. 2005), X-ray limit (2-10 keV) ~5 x 1034 erg s-1 (Shtykovskiy et al. 2005)(Shtykovskiy et al. 2005)

• Radio limit of central source from 8 GHz image ~ 1 mJy

• Assume flat spectrum 20 GHz, LPWN ~ 3 x1031 erg s-1

• For the most conservative limit on E of central pulsar, assume PWN only emits at radio frequencies and LPWN = EPSR

• For Po = 200 ms, EPSR = 3 x1031 erg s-1, then Bo ~ 6 x 1010 G

Well within the range of possible pulsar birth parametersWell within the range of possible pulsar birth parameters

..

.

PWN limits do not rule out a perfectly plausible 20-year old pulsar at the centre of SN 1987A

Manchester, 2007Manchester, 2007