Evolution of magnetar-powered supernovae

Miyu Masuyama, RESCEU collaborator : Toshio Nakano, Toshikazu Shigeyama

RIKEN-RESCEU joint meeting 2016/07/25-27

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1. Neutron stars

2

• Neutron Stars (NS) • generated by core collapse supernovae • observed NS, a few hundreds

• Power sources of them • rotation energy • gravitational energy of accreting matters • thermal energy • magnetic field energy

1. Neutron stars

3

• Neutron Stars (NS) • generated by core collapse supernovae • observed NS, a few hundreds

• Power sources of them • rotation energy • gravitational energy of accreting matters • thermal energy • magnetic field energy

-> We focus on NS with strongest magnetic fields, “Magnetar”.

2. Magnetars

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• NS with strong magnetic fields

( typical neutron stars : B~1012 G )

• Spin down. Pdot > 0 • Radiate X-ray by using magnetic

fields. Lx ~ 1035 erg/s >> Lspin -> rapidly spin & Highly magnetize at their birth.

-> The mechanism for growth of strong magnetic fields & what supernovae generate magnetars have not been well understood.

10-22

10-20

10-18

10-16

10-14

10-12

10-10

10-8

0.001 0.01 0.1 1 10 100

Perio

d de

rivat

ive(s/

s)

Period(1/s)

Radio PulsarMagnetar

Binary10-22

10-20

10-18

10-16

10-14

10-12

10-10

10-8

0.001 0.01 0.1 1 10 100

Perio

d de

rivat

ive(s/

s)

Period(1/s)

10 16G

10 15G

10 14G

10 13G

10 12G

10 11G

1kyr

1Myr

10kyr

100kyr

10Myr

100Myr

(s)(ATNF pulsar catalog)

North east (NE)506039010

North West (NW)506037010

South East (SE)50604010

South West (SW)506038010

1E 2259+586 (AXP)404076010

XIS1

XIS0,3

1E 2259+586

Suzaku X-ray image, CTB109 (SNR) & 1E2259+586 (magnetar)

• discovered magnetars : about 30 ( ATNF pulsar catalog )

• some associate with SNR 　　　　　　　　　　　　　( e.g. Kes 73, CTB 109 )

• Observations of such SNR : • Progenitors are very massive ( >30M◉)

( e.g. Figer +05, Kumar +12 )　 • ESNR ~ 1051 erg

( e.g. Vink & Kuiper 06 )　

• Theoretical prediction※ : • Erot ~ 1052 erg are injected

to stellar envelope by magnetic dipole radiation. ※ Magnetars have very short spin periods (P0 < 3ms) and highly strong magnetic field (B0 > 1015G) at their birth (α-dynamo effect) (Duncan & Thompson 92). Therefore they have Erot ~ 1052 erg and inject its energy to stellar envelope.　

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3. Previous works

2.1 何をやっていたのか ( 私の修論の復習 )

(A). A mechanism without rapidly rotation amplify a magnetic field of magnetar. -> Erot < 1052 erg

(B). Most of rotation energy is used for something (e.g. GW, binding energy). (C). Underestimate energy of SNR associated with magnetars. -> ESNR > 1051 erg

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4. Our work

core collapse of massive star supernove supernove remnant

R ~ 1010 cm R ~ 1019 cm

t ~ 0 sec t ~ 10,000 yrst ~ 100 daysexplosion expansion

Erot ~1052 erg (A)?? ESNR ~1051 erg (C)?? (B)??

2.1 何をやっていたのか ( 私の修論の復習 )

(A). A mechanism without rapidly rotation amplify a magnetic field of magnetar. -> Erot < 1052 erg

(B). Most of rotation energy is used for something (e.g. GW, binding energy). (C). Underestimate energy of SNR associated with magnetars. -> ESNR > 1051 erg

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4. Our work

core collapse of massive star supernove supernove remnant

R ~ 1010 cm R ~ 1019 cm

t ~ 0 sec t ~ 10,000 yrst ~ 100 daysexplosion expansion

-> We perform 1D hydrodynamical simulations of evolutions of magnetars for 10,000 yrs to investigate the relation between Erot and ESNR.

Erot ~1052 erg (A)?? ESNR ~1051 erg (C)?? (B)??

8 distance from the center

WR star just before explosion ( Iwamoto et al. 1998 )

Energy Injection to stellar envelope by magnetic dipole radiationMagnetar

CSM ISM

5 pc1010 cm108 cm106 cm

dens

ity

10-24 g/cm3

M~40M◉

stellar envelope

5. Set up for simulations

9 distance from the center

WR star just before explosion ( Iwamoto et al. 1998 )

Energy Injection to stellar envelope by magnetic dipole radiationMagnetar

CSM ISM

5 pc1010 cm108 cm106 cm

dens

ity

10-24 g/cm3

M~40M◉

stellar envelope

5. Set up for simulations

Calculation region

10 distance from the center

WR star just before explosion ( Iwamoto et al. 1998 )

Energy Injection to stellar envelope by magnetic dipole radiationMagnetar

CSM ISM

5 pc1010 cm108 cm106 cm

dens

ity

10-24 g/cm3

M~40M◉

stellar envelope

5. Set up for simulations

Calculation region

1D hydrodynamical simulation

+ Q

Q = L(t) injected from rotation energy of a magnetar @ inner most region

0 @ the other region{

continuity equation

equation of motion

energy equation

=-

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inject energy to stellar envelope by magnetic dipole radiation

0.01 102 106 108 1014

Energy injection time [s]

Ene

rgy

inje

ctio

n ra

te [e

rg/s

]

1015 G

1012 Gtp = 0.1 s

103 s

109 s

Magnetar Erot = 1052 erg ~ lω2

B0=1017 G

6. Magnetars as a explosion engine

rot

rot

-14

-11

-8

1.0×1019 4.0×1019

log p

[g/cm

/s2 ]

r [cm]

(c)

0.0

5.0

1.0

1.5

υ×1

07 [cm

/s]

(b)

-29

-26

-23

log ρ

[g/cm

3 ]

(a)

dens

itypr

essu

reve

loci

ty

12

t = 4,000 yrs after explosion

10.0

15.0

distance from the center

ejectaCSM

ISM

forward shock

reverse shock

Initial profile

log ρ ejecta

CSM ISM

shock are formed by energy injection from magnetar.

7. Time evolution of shock waves

distance from the center

• ESNR ~ Erot + Eν,heating + Enuc + Ebind

8. Energy of neutrino-heating

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νe

νe

ー νe + n -> p + e-

νe + p -> n + e+

stalled shockneutrino sphere

※in the core

ー

-> The stalled shock is revived by depositing of a part of energy 1051 erg carried away by neutrino νe, νe.ー

• Eν,heating ~ 1051 erg

• ESNR ~ Erot + Eν,heating + Enuc + Ebind

• rough estimation of nuclear energy under assumption that the matter which exceed T > 5×109 K will be 56Ni.

->

• We should calculate hydrodynamical simulations including nuclear reactions and feedback to hydrodynamical simulations for magnetar-powered supernovae.

9. Energy of nuclear reactions

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9

10

2 3 4 5

log Tmax [K]

Mass [solar mass]

magne

tar�

28Si->56Ni@T>5×109K�

P0=2msec,energyisinjectedinstantly�

P0=2msec,B0=5×1016G�

• ESNR ~ Erot + Eν,heating + Enuc + Ebind

• Progenitors of magnetars are considered to be massive stars.

• Ebind ~ - 5 × 1051 erg ( just before explosion ) in case that a progenitor mass is 40 M◉

10. Gravitational binding energy

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( e.g. Safi-Harb & Kumar 2012 )

Magnetar Progenitor mass1E 1048.1-5937 (Gaensler+ 2005) 30-40 M◉

CXO J164710.2-455216 (Muno+ 2006) > 40 M◉

SGR1806-20 (Figer+ 2005) ~50 M◉

SGR 1900+14 (Davies+ 2009) 17 M◉

1E 1841–045 (Kumar+2014) >> 20 M◉

SGR 0526–66 (Uchida+2015) ~26 M◉

1E 2259+586 (Nakano PhD thesis) ~40 M◉

-> Most of the rotation energy 1052 erg is used to climb up the gravitational potential well of a massive star and the resultant SNR possesses the rest of the energy ESNR ~ 1051 erg.

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1e+49

1e+50

1e+51

1e+52

0.01 1 100 10000 1e+06 1e+08 1e+10 1e+12

52�

52�

51�

50�

49� 52�-2� 0� 2� 4� 6� 8� 10� 12�

Time after explosion, log t [sec]

Ene

rgy,

log

E [e

rg]

Gravitational energy, -Eg

Internal energy, Ei

Kinetic energy, Ek

Energy injection from magnetar Erot ~ 1052 erg

ESNR ~ 1051 erg

11. Time evolution of energy

rESNR

Ebind

Einject

~ 1052 + 1051 + 1051 - 5×1051 ~ 1051 erg

• ESNR ~ Erot + Eν,heating + Enuc + Ebind

• We perform 1D hydrodynamical simulations to investigate the relation between energy of magnetars at their birth Erot and energy of supernova remnants associated with magnetars ESNR.

• Most of the rotation energy is used to climb up the gravitational potential well of a massive star and the resultant supernova remnant possesses the rest of the energy ESNR ~ 1051 erg.

• We should carry out simulations including nuclear reactions and feedback to hydrodynamics.

12. Summary

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