Pair-instabilityсверхновыеи...

Pair-instability сверхновые ипредвестники коллапса звезд

С.И.Блинников

sergei.blinnikov@itep.ru

ITEP, SAI, also partly IPMU

НИИЯФ15y12-Prosper – p. 1

SINP MSU, 15th May 2012

S.I.Blinnikov 1,2,3

1Institute for Theoreticaland Experimental Physics(ITEP), Moscow

2Sternberg AstronomicalInstitute (SAI), MSU, Moscow

3work partly done at IPMU,Tokyo University, Kashiwa

НИИЯФ15y12-Prosper – p. 2

Supernova SN1994D in NGC4526Shocks are not important for light in “Nobel prize” SNe Ia

НИИЯФ15y12-Prosper – p. 3

SN 2006gy

Ofek et al. 2007, ApJL

Smith et al. 2007, ApJ

Shocks arevital for

explaining lightof those

superluminousevents formany

months...

НИИЯФ15y12-Prosper – p. 4

SNR Tycho in X-rays (Chandra)

...and thousands of years in SNRs

НИИЯФ15y12-Prosper – p. 5

Supernova: order of events

Core collapse (CC) or explosion

НИИЯФ15y12-Prosper – p. 6

Supernova: order of events

Core collapse (CC) or explosion

Neutrino/GW signal, accompanying signals

НИИЯФ15y12-Prosper – p. 6

Supernova: order of events

Core collapse (CC) or explosion

Neutrino/GW signal, accompanying signals

Shock creation if any, propagation and entropyproduction inside a star

НИИЯФ15y12-Prosper – p. 6

Supernova: order of events

Core collapse (CC) or explosion

Neutrino/GW signal, accompanying signals

Shock creation if any, propagation and entropyproduction inside a star

Shock breakout (!)

НИИЯФ15y12-Prosper – p. 6

Supernova: order of events

Core collapse (CC) or explosion

Neutrino/GW signal, accompanying signals

Shock creation if any, propagation and entropyproduction inside a star

Shock breakout (!)

Diffusion of photons and cooling of ejecta

НИИЯФ15y12-Prosper – p. 6

Core-Collapse-SN (CCSN)

Standard description of Chronology

1 sec: Core collapse, bounce, or SASI⋆), or rotMHD,shock revival

1 min to 1 day: shock propagates and breaks out (1stEM signature). Fallback? NS vs. BH formation?

Mins to days: Final ejecta acceleration to homology(velocity u ∝ r)

⋆) Standing accretion shock instability

Actually some weak EM signals are inevitably producedbefore shock breakout

НИИЯФ15y12-Prosper – p. 7

Burning in center and in shells

НИИЯФ15y12-Prosper – p. 8

Many shells next few slides from Raffelt (2010) and other sources

НИИЯФ15y12-Prosper – p. 9

Newborn NS

НИИЯФ15y12-Prosper – p. 10

NS energy estimates

НИИЯФ15y12-Prosper – p. 11

First messengers of explosions

Neutrino?

НИИЯФ15y12-Prosper – p. 12

First messengers of explosions

Neutrino? → Gravitational waves?

НИИЯФ15y12-Prosper – p. 12

First messengers of explosions

Neutrino? → Gravitational waves? →

Radio waves? At least in atmospheric explosions

НИИЯФ15y12-Prosper – p. 12

First messengers of explosions

Neutrino? → Gravitational waves? →

Radio waves? At least in atmospheric explosions →

Shock breakout

НИИЯФ15y12-Prosper – p. 12

SN classification

light curveIIb IILIIP

IIn

ejecta−CSMinteraction

core collapsethermonuclear

yes

yesno

no

noSiIIHeI yes

hypernovae

strong

shape

Ia IcIb

Ib/c pec

III H

Turrato 2003

НИИЯФ15y12-Prosper – p. 13

Extremely bright Type IIn SNe

V-band(Drake et al. 2010)

SN1987A and atypical SNII belowthe frame!

НИИЯФ15y12-Prosper – p. 14

H-poor superluminous SNe

Quimby et al. 2011

−50 0 50 100 150Rest−frame phase (days)

−16

−18

−20

−22A

bsol

ute

u−ba

nd A

B m

agni

tude

SS SS

SCP 06F6SN 2005apPTF09cndPTF09cwlPTF09atuPTF10cwr

Still enigmatic. Most probably explained by a long livingradiative shock. No better model is suggested

НИИЯФ15y12-Prosper – p. 15

Supernova 1987A Neutrinos

НИИЯФ15y12-Prosper – p. 16

SN 1987A NeutrinosTen neutrino events were detected in a deep mine neutrino detection facility in Japan which

coincided with the observation of Supernova 1987A. They were detected within a time

interval of about 15 seconds against a background of lower energy neutrino events. A similar

facility, IMB in Ohio detected 8 neutrino events in 6 seconds. These observations were made

18 hours before the first optical sighting of the supernova.

НИИЯФ15y12-Prosper – p. 17

Superlumnal neutrino cartoons...

НИИЯФ15y12-Prosper – p. 18

Longo PRD 36(1987)3276

Distance = 1.6 × 105 ly, ∆t ≈ 3h, hence

|(c − cν)/c| . 3h/(1.6 × 105 × 365 × 24) = 2 × 10−9

Where does ∆t ≈ 3h come from?Could the constraint be improved?

НИИЯФ15y12-Prosper – p. 19

SN1987A discovery

Timing (times in Universal Time)7:36, 23 February, neutrinos observed9:30, 23 February

Albert Jones, amateur astronomer, observesTarantula Nebula in LMCHe sees nothing unusual

10:30, 23 FebruaryRobert McNaught photographs LMCWhen plate is developed, SN1987A is there.Some 20 hours later, Ian Shelton’s discovery.

НИИЯФ15y12-Prosper – p. 20

SN87A early observations

Blinnikov with K.Nomoto ea

НИИЯФ15y12-Prosper – p. 21

SN87A early observations

НИИЯФ15y12-Prosper – p. 22

Improvement of cν constraint

If the flash at shock breakout were observed we would get

|(c − cν)/c| . 2 × 10−10

Much better improvement is possible in principle!If a precollapse suspect is monitored and its prompt quakeis registered e.g. in radio simultaneously with ν and/or GWsignal.

НИИЯФ15y12-Prosper – p. 23

ν detectors

НИИЯФ15y12-Prosper – p. 24

Next generation ν detectors

НИИЯФ15y12-Prosper – p. 25

Gravitational Waves from CCSNe

http://numrel.aei.mpg.de/images

These images are copyright of AEI, ZIB, LSU and SISSA

НИИЯФ15y12-Prosper – p. 26

GW detectors

НИИЯФ15y12-Prosper – p. 27

ν detectors

НИИЯФ15y12-Prosper – p. 28

GW LIGO estimates

НИИЯФ15y12-Prosper – p. 29

SN 2006gy

Ofek et al.

2007, ApJL,

astro-

ph/0612408)

Smith et al.

2007, Sep. 10

ApJ, astro-

ph/0612617)

НИИЯФ15y12-Prosper – p. 30

Brightest. Supernova. Everby N.Smith

НИИЯФ15y12-Prosper – p. 31

It was Most Luminous SN ever

НИИЯФ15y12-Prosper – p. 32

Extremely bright Type IIn SNe

V-band(Drake et al. 2010)

НИИЯФ15y12-Prosper – p. 33

Luminous SN: too many photons?

Now we know a few other SNe with peak luminosity evenhigher than SN 2006gy.

Total light 1051 ergs: 2 orders ofmag higher than normal core

collapsing SN and 1 order morethan brightest thermonuclear SNTo explain this light we inevitably involve large stellar

masses.I will try to explain why the evolution of stars with M > 10M⊙

is quite different from low mass stars, and what happens atM ∼ 100M⊙

НИИЯФ15y12-Prosper – p. 34

НИИЯФ15y12-Prosper – p. 35

НИИЯФ15y12-Prosper – p. 36

Stellar evolution

HR (L− Teff) diagram needed for comparison withobservations

НИИЯФ15y12-Prosper – p. 37

Compression in centereven if Rout grows

1974ARA&A..12..215I

НИИЯФ15y12-Prosper – p. 38

Central Pressure

Omitting all coefficients of order unity, pressure and densityin the center are:

Pc ≃GNM

2

R4, ρc ≃

M

R3.

and we find

Pc ≃ GNM2

3ρ4/3c .

НИИЯФ15y12-Prosper – p. 39

Tc ∝ M2/3ρ1/3c in ND stars

So if we have a classical ideal plasma with P = RρT/µ,where R is the universal gas constant, and µ – meanmolecular mass,

Tc ≃GNM

2/3ρ1/3c µ

R.

With µ ≃ 1 for H-He fully ionized plasma we get for the Sun

Tc ≃ 107 K ≃ 1 keV.

НИИЯФ15y12-Prosper – p. 40

Now check: Tc ∝ M2/3ρ1/3c

НИИЯФ15y12-Prosper – p. 41

Check: Tc ∝ M2/3ρ1/3c

НИИЯФ15y12-Prosper – p. 42

Not so for lower masses

НИИЯФ15y12-Prosper – p. 43

Degeneracy of electrons

НИИЯФ15y12-Prosper – p. 44

Degeneracy of electrons

НИИЯФ15y12-Prosper – p. 45

M > 10M⊙ never degenerate

НИИЯФ15y12-Prosper – p. 46

Compare with old Iben’s results

1974ARA&A..12..215I

НИИЯФ15y12-Prosper – p. 47

Check: Tc ∝ M2/3ρ1/3c

НИИЯФ15y12-Prosper – p. 48

Check: Tc ∝ M2/3ρ1/3c

НИИЯФ15y12-Prosper – p. 49

If radiation dominates in P

When plasma is

radiation-dominated (for massive

stars), then, P ∝ T 4, and

Tc ∝ M 1/6ρ1/3c .

НИИЯФ15y12-Prosper – p. 50

HR and Tc − ρc evolution

НИИЯФ15y12-Prosper – p. 51

Compute stars yourself

Computational Astrophysics:http://rainman.astro.uiuc.edu/ddr/

The Digital Demo Room

10000 stars evolve together – find on this site – click here

7 stars of masses 20M⊙ < M < 80 evolve in a combined run

and explode as SNe – find on this site – click here

НИИЯФ15y12-Prosper – p. 52

The carbon-oxygen cores of low mass stars turn out to bedegenerate at the moment when the carbon burningbegins. The temperature of their interiors is also stronglyaffected by the neutrino energy losses. Should the carbonburning only begin in degenerate conditions, it acquires aviolent, explosive nature giving rise to the explosion of TypeIa supernovae.

НИИЯФ15y12-Prosper – p. 53

On hydrodynamical instability

Equilibrium requires (in Newtonian gravity):

Pc ≃ GNM2/3ρ4/3c .

This implies that adiabatic exponent

γ < 4/3 may lead to a hydrodynamic

instability.

НИИЯФ15y12-Prosper – p. 54

Mechanical stability

×

5/3

4/3

S1 > S2 > S3

lg ρ

lgP

M = const

НИИЯФ15y12-Prosper – p. 55

Relativistic particles

lead to γ → 4/3

We have γ ∼ 4/3 due to high entropy S (photons and

e+e− pairs).At low S → 0 we have γ → 4/3 due to high Fermi energyof degenerate electrons at high density ρ.

НИИЯФ15y12-Prosper – p. 56

Causes for a collapse: pairs

For very massive stars the radiation pressure aT 4/3 mustbe much larger than RρT .Here per gram

Eth = aT 4/ρ

and from

TS = Eth + P/ρ for µ = 0,

we find per unit mass

S =4

3

aT 3

ρ.

НИИЯФ15y12-Prosper – p. 57

Photons and ...

T =

(

3

4

Sρ

a

)1/3

, P =1

3aT 4 =

a

3

(

3

4

Sρ

a

)4/3

,

i.e. P ∝ ρ4/3 for constant S, and γ = 4/3. When T >∼ 0.1mec

2

for small µ in non-degenerate gas the pairs (e+e−) are born

intensively, so for T ≫ mec2 the total thermal energy

Ethρ = aT 4 +7

4aT 4 =

11

4aT 4,

(7a/8) is added per each polarization of fermions.Exact formulae see, e.g., SB,Dunina-Barkovskaya,DKN,1996, ApJS.

НИИЯФ15y12-Prosper – p. 58

. . . and e+e− pairs

pressure

P =11

12aT 4,

and entropy per gram

S =11

3

aT 3

ρ.

Thus for T ≫ mec2 again P ∼ ρ4/3, but the coefficient is

smaller

P =11

12aT 4 =

11a

12

(

3

11

Sρ

a

)4/3

,

so in between the slope logP – log ρ must be less than 4/3.

НИИЯФ15y12-Prosper – p. 59

Pair instability

A radiationdominated starwas already atthe verge of theloss of the stability

(P ∝ ρ4/3), andnow it is unstable if(γ < 4/3).

НИИЯФ15y12-Prosper – p. 60

Open evolution code

Hertzsprung-Russell and Center Temperature-DensityTracks for Metallicity Z = 0.02. The “He” symbols showwhere the net of power from nuclear reactions beyondhydrogen burning minus neutrino losses from all sourcesreaches the break-even point.

Paxton: P.Eggleton evolution code

НИИЯФ15y12-Prosper – p. 61

Higher mass means higher Tcfor the same ρ, hence pair creation

НИИЯФ15y12-Prosper – p. 62

Open evolution code

Previous plot is taken from here

Paxton: P.Eggleton evolution code

Centre Temperature-Density Tracks for Metallicity Z = 0.02.The “He” symbols show where the net of power from

nuclear reactions beyond hydrogen burning minus neutrinolosses from all sources reaches the break-even point.

Более наглядные графики ниже — Roni WaldmanarXiv:0806.3544.

Better looking plots below are from Roni Waldman’s eprintarXiv:0806.3544.

НИИЯФ15y12-Prosper – p. 63

Massive stars and their He-cores

8.5

8.6

8.7

8.8

8.9

9

9.1

9.2

9.3

9.4

9.5

9.6

9.7

9.8

9.9

10

3 4 5 6 7 8 9 10

log(

T c)

log(ρc)

Fe disintegration

Pair instability

M 20

He 8

M 80

He 36

Each line is labeled “M” forstellar models and “He” forHe-core models, followedby the mass of the modelor of the core. Here arestars that reach corecollapse avoiding pair

instability.

НИИЯФ15y12-Prosper – p. 64

3 outcomes of pair-instability

Here are only He-coremodels, labeled by “He”and the mass of the core.

They all reach pairinstability, subsequently

experiencing 1) pulsations(He48),

2) complete disruption(He80), or

3) direct collapse (He160). 8.5

8.6

8.7

8.8

8.9

9

9.1

9.2

9.3

9.4

9.5

9.6

9.7

9.8

9.9

10

3 4 5 6 7 8 9 10

log(

T c)

log(ρc)

Fe disintegration

Pair instability

He 48

He 80

He 160

НИИЯФ15y12-Prosper – p. 65

γ < 4/3 domain in T − ρ plane

Gary S. Fraley 1968. Pair-instability SNe

НИИЯФ15y12-Prosper – p. 66

Adiabatic γ for pairs at very low density

D.K.Nadyozhin 1974, see SB,Dunina-Barkovskaya,DKN,1996, ApJS

НИИЯФ15y12-Prosper – p. 67

Umeda and Nomoto 2007

НИИЯФ15y12-Prosper – p. 68

Woosley et al. 2007, 103 M⊙ star

This gives theMost LuminousSupernovae (!),because, instead ofone SN explosion,we have severalmass ejectionsand collisions ofmass shells whichproduce brightradiating shocks.

НИИЯФ15y12-Prosper – p. 69

SN IIn structure, Chugai, SB ea’04

(photosphere)

НИИЯФ15y12-Prosper – p. 70

Shocks in SNe IIn

A long livingshock: anexample forSN1994w oftype IIn. Densityas a functionof the radius rin two modelsat day 30. Thestructure tendsto an isothermalshock wave.

НИИЯФ15y12-Prosper – p. 71

Woosley, Blinnikov, Heger, s103

Pulsational pair instability may give the Most Luminous Supernovae!НИИЯФ15y12-Prosper – p. 72

Two mass ejections

НИИЯФ15y12-Prosper – p. 73

Light curve for SN2006gyfrom Woosley, SB, Heger (2007)

НИИЯФ15y12-Prosper – p. 74

Stella: LCs for SN2006gynew runs

НИИЯФ15y12-Prosper – p. 75

Double explosion: old idea

Grasberg & Nadyozhin (1986)

НИИЯФ15y12-Prosper – p. 76

Hydro structure 60 d

НИИЯФ15y12-Prosper – p. 77

60 d, mass coordinate

НИИЯФ15y12-Prosper – p. 78

‘Visible’ disk of SN 2006gy

НИИЯФ15y12-Prosper – p. 79

Star formation rate = SFR

Smartt S. J., 2009, ARAA, 47, 63

0 2 4 6 8 100

20

40

60

80

100

R(z

) (n

um

be

r s

−1)

redshift z

NS births ccSNe

НИИЯФ15y12-Prosper – p. 80

Nearby candidate:

Betelgeuse in ORION – distance 130 pc

НИИЯФ15y12-Prosper – p. 81

Neutrino warning

НИИЯФ15y12-Prosper – p. 82

Neutrino emission

НИИЯФ15y12-Prosper – p. 83

From Odrzywolek et al.

НИИЯФ15y12-Prosper – p. 84

Neutrinos: Milky Way warning

Red circle is expected range forGADZOOKS!/Super-Kamiokande detector

Green circle is expected range for Gd-loaded 0.5 Mt waterdetector (UNO, Hyper-Kamiokande, LAGUNA)

Blue circle is expected range for hypothetical 10 Mtunderwater detector (TITAN-D, underwater balloon)

Yellow circle is expected range for futuristic “Gigaton Array”detector — for three hour warning range is much larger thanGalaxy radius

НИИЯФ15y12-Prosper – p. 85

Neutrinos: 1 day MW warning

НИИЯФ15y12-Prosper – p. 86

3 hours MW warning

НИИЯФ15y12-Prosper – p. 87

Summary

Radiating shocks are most probable sources of light inmost luminous supernovae of type IIn like SN2006gy

Most luminous SN IIn events may be observed at highz [for years due to (1 + z)] and may be useful as direct,primary, distance indicators in cosmology

НИИЯФ15y12-Prosper – p. 88

Conclusions-1

The shock wave which runs through rather densematter surrounding an exploding star can produceenough light to explain very luminous SN events. No56Ni is needed in this case to explain the light curvenear maximum light (some amount may be needed toexplain light curve tails).We need the explosion energy of only 2-4 Bethe for the

shell with M = 3 − 6M⊙ and R . 1016cm. NARROWLINES MAY NOT BE PRODUCED!

НИИЯФ15y12-Prosper – p. 89

Conclusions-2

Questions on the latest phases of star evolution arise:

Is it possible to form so big and dense envelopes?And how?

Time scale for such a formation

How far can the envelope extend?

Density and temperature profiles inside theenvelope right before the explosion

Question to observations: try to find traces of suchshells for bright explosions.(There are spectral evidence of circumstellar shells fortype IIn and Ibn SNe. Is it possible to find C–Oenvelopes as well?)

НИИЯФ15y12-Prosper – p. 90

Conclusions-3

Many technical problems in light curve calculations:

line opacities;

dimensionality: 3D is preferable, since the envelopecan most probably be clumpy;

NLTE spectra

НИИЯФ15y12-Prosper – p. 91

Acknowledgements

Our work is supported by Grants of the Government of theRussian Federation 11.G34.31.0047, RFBR 10-02-00249,10-02-01398, RF Sci. School 3458.2010.2, 3899.2010.2, bya grant IZ73Z0-128180/1 of the Swiss National ScienceFoundation (SCOPES), and in Germany by MPA guestprogram. This research has been partly done at IPMU,Tokyo University, and supported in part by World PremierInternational Research Center Initiative, MEXT, Japan

НИИЯФ15y12-Prosper – p. 92