Mass ejec(on from NS-­‐NS merger and Kilonova/Macronova
Kenta Hotokezaka (Hebrew University of Jerusalem)
Collaborators: K. Kiuchi, T. Muranushi, Y. Sekiguchi, and M. Shibata (YITP) K. Kyutoku (UWM), H. Okawa (Waseda U), and K. Taniguchi (U. of Tokyo) M. Tanaka (NAOJ), S. Wanajo (RIKEN) T. Piran (Hebrew U. of Jerusalem)
Outline
•  Electromagne(c counterparts of Gravita(onal waves •  Mass ejec(on at binary neutron star merger •  A kilonova/macronova candidate associated with a short GRB 130603B
Gravita(onal-­‐wave astronomy
GW
Advanced LIGO
Compact binary merger GW Advanced Virgo
KAGRA
Expected rate(NS-­‐NS merger) Abadie et al (2010)
1st genera(on (Ini(al LIGO, Virgo) 2nd genera(on(Advanced LIGO, Virgo, KAGRA)
0.0002 〜　0.2 /yr 0.4 〜 400 /yr
NS-­‐NS merger : Dynamics and GW waveform density
M1 = 1.4M sun
M 2 = 1.3M sun
log(density g/cc)
Waveform
Numerical rela(vity computa(on.
Hotokezaka, et al. (2013) Gravita(onal wave from compact binary merger
Matched filter analysis
Data：Noise＋GW
Theore(cal Template
2e-21
0.15
0.1
0.05
h
1e-21
0
-0.05
h
-0.1
-0.15
0
2
2.01
2.02
2.03
time[s]
2.04
2.05
-1e-21
-2e-21
2
2.01
2.02
2.03
2.04
2.05
Compute the overlap between data and template time[s]
Because the advanced detectors will watch 〜10^5 galaxies, many signals will be expected around the detec(on threshold. Electromagne(c counterparts of GWs
ü  Confirma(on of the detec(on of GWs from NS-­‐NS around detec(on threshold, (like Neutrino burst associated with supernova 1987A) ü  Localiza(on of GW sources (GW localiza(on is not good), => Determine host galaxies. ü  They carry different informa(on from GWs. (e.g. Mass of ejected radioac(ve nuclei) But to discover them won’t be easy. => Theore(cal expecta(ons are needed to make observa(onal strategies.
Baryon ejec(ons drive EM counterparts
Wind
NS-­‐NS Merger
or
Hypermassive NS with accre(on torus
GRB Jet
Black hole with accre(on torus
1,Dynamical ejecta: Tidal tail & shocked majer 2, Wind driven by viscosity, neutrino, recombina(on
3, A GRB jet may be launched at a certain (me.
Luminosity
Expected Lightcurve
52 GRB (X~γ)
log(L) [erg/s] 50 Extended Emission (X)
Refs: Nakar (2007) Norris & Bonnell (2006) Sari, Piran, Narayan (1998) Li & Paczynski (1998) Nakar & Piran (2012) Kyutoku, Ioka, Shibata (2012) Kelley, Mandel, Ramirez-­‐Ruiz (2012)
48 GRB Anerglow (X)
46 44 Merger Breakout (X)
Log log(Lν) [erg/s/Hz] Luminosity(erg/s/Hz) 42 30 GRB Anerglow (visible)
GRB anerglow Merger remnant (radio)
(radio)
28 26 Merger Breakout (radio)
Kilonova /Macronova (NIR)
-­‐2 0 2 4 6 8 10
log(t) [s]
(me
Luminosity
Expected Lightcurve (4π)
52 GRB (X~γ)
log(L) [erg/s] 50 Extended Emission (X)
48 GRB Anerglow (X)
46 44 Merger Breakout (X)
Log log(Lν) [erg/s/Hz] Luminosity(erg/s/Hz) 42 30 GRB Anerglow (visible)
GRB anerglow Merger remnant (radio)
(radio)
28 26 Merger Breakout (radio)
Kilonova /Macronova (NIR)
-­‐2 0 2 4 6 8 10
log(t) [s]
(me
Luminosity
Expected Lightcurve(4π, independent of environment)
52 GRB (X~γ)
log(L) [erg/s] 50 Extended Emission (X)
48 GRB Anerglow (X)
46 44 Merger Breakout (X)
Log log(Lν) [erg/s/Hz] Luminosity(erg/s/Hz) 42 30 GRB Anerglow (visible)
GRB anerglow Merger remnant (radio)
(radio)
28 26 Merger Breakout (radio)
Kilonova /Macronova (NIR)
-­‐2 0 2 4 6 8 10
log(t) [s]
(me
What is “kilonova/macronova”
Beta decay of radioac(ve nuclei => Keep ejecta at high T
A kilonova/macrovova was proposed by Li & Paczynski in 1998 as an observable consequence of NS-­‐NS mergers. At NS-­‐NS merger ü  A frac(on of material is ejected as radioac(ve nuclei. ü  Ejecta can be bright object due to radioac(ve hea(ng. ü  Luminosity: Nova < NS-­‐NS merger < Supernova.
Luminosity erg/s
Kilonova/Macronova and Ejecta property
Based on current understanding ∝ M ej t −1.3〜 100 – 1000 x Nova (at the peak of a lightcurve) Diffusion (me∝ v −2/3 M 1/3 〜5 days
ej
(me
ü  Higher ejecta mass => Brighter signal ü  Faster ejecta velocity => Brighter signal Various ouylows of NS-­‐NS merger GR
50
EK/10 erg
10
GRB jet
1
Γ>30
0.1
NS-­‐NS breakout
0.01
1e-07 1e-06 1e-05 0.0001 0.001 0.01
M/Msun
GRB jet: Nakar (2007) Newton
GRB cocoon: jet(et a=30)
GRB
Nagakura l (2014) GRB
cocoon
NS-­‐NS merger breakout: wind
BH-torus
Kyutoku, Ioka, &
Shibata (2013) HMNS
wind
Dynamical ejecta: Hotokezaka et al. (2013) NS-NS
breakout
Piran et al. (2013) Bauswein et al. (2013) BH-­‐torus wind: Fernandez & Metzger (2013) Just et al. (2014) HMNS – torus wind: Dessart et al. (2009) Metzger & Fernandez (2014) Perego et al. (2014)
0.1
Dynamical ejecta is likely dominant source of kilonova/macronova. Numerical simula(on for dynamical ejecta
We perform Numerical Rela(vity simula(ons using AKA et al.
SACRA code Yamamoto + 2009 3
H4
MS1
Total mass = 2.6 ~2e+15
2.9 Msun 1e+15
Mass ρrca(o (g/cm3=
) 0.8 ~ 1 APR4
2.5
ALF2
H4
M (solar mass)
Solve ・Einstein equa(on ・Hydrodynamics with an Equa(on of State APR4
(4-­‐different NS models) ALF2
For piecewise polytropic EOSs See Read et al., D(2009) PHYSICAL
REVIEW
87, 024001
(2013)
2
MS1
1.5
1
0.5
0
10
15
20
R (km)
. Left: The gravitational mass as a function of the central density !c for spherical neutron stars in APR4, ALF2,
the solid, dashed, dotted, and dash-dotted curves). Right: The same as the left panel but for the gravitational mass
circumferential radius.
Mass ejec(on on equatorial plane
Model : 1.2Msun – 1.5Msun, APR
300 km x 300 km 2400 km x 2400 km
log(density g/cc)
Mass ejec(on on equatorial plane
Model : 1.2Msun – 1.5Msun, APR
300 km x 300 km 2400 km x 2400 km
log(density g/cc)
Mass ejec(on : Mej 〜 0.01Msun, v 〜 0.2c
Ejec(on Mechanism ~(dal torque~
log(density g/cc)
Heavy NS
Light NS
1.  Lighter NS is elongated 2.  Outer material get angular momentum Feature: Ejecta expand on the equatorial plane Mass ejec(on on the Meridional plane
Model : 1.2Msun – 1.5Msun, APR
(x-­‐z plane)
300 km x 150 km 2400 km x 1200 km
log(density g/cc)
Mass ejec(on on the Meridional plane
Model : 1.2Msun – 1.5Msun, APR
(x-­‐z plane)
300 km x 150 km 2400 km x 1200 km
log(density g/cc)
NS-­‐NS Ejecta is spheroidal. 0
30
40
0
10
20
30
40
Ejec(on Mechanism ~shock hea(ng~
t (ms)
ime for models with m1 = m2 = 1.35M (left), and m1 = 1.2M and m2 = 1.5M
binaries, the central density of heavier neutron stars are plotted. th = 1.8 is
Specific internal energy
Equatorial plane
Spiral arm sweeps majer Meridian plane
Mass is ejected due to the HMNS forma(on Model=135Msun-­‐1.35Msun, APR
Dependence of Ejecta mass on NS EOS
Mesc/10-3Msun
10
Hotokezaka + (2013)
8
If HMNS is formed,
6
4
Radius of NS 2
11
12
13
R1.35 [km]
14
15
Mass of Ejecta
Systematics of dynamical mass ejection, nucleosynthesis, and radioactively powered electromagnetic signals
Similar result is obtained by MPS group.
0.012
0.02
Bauswain + (2013)
0.008
Mejecta [Msun]
Mejecta [Msun]
0.01
0.006
0.004
0.015
0.0001<Mej<0.01Msun
0.01
0.002
0
10
9
11
12
R
13
14
[km]
1.35
15
16
0.005
11 assive 12neutron 13 star f14
15
No m
orma(on
R
[km]
1.35
Velocity distribu(on
dM/dv
0.1
0.01
0.001
0.001
0.01
0.1
1
v
Most of ejecta has the velocity 0.1c 〜0.2c
26
26
Expected lightcurves of k26ilonova/macronova
8m
27
Tanaka & KH 0
5 2013 10
15
Days after the merger
0
20
20
22
21
21
1m
23
24
4m
25
22
23
24
25
Observed magnitude
Op(cal
r band
200 Mpc
Observed magnitude
21
0 5
5 10
15 20
15
Masaomi-­‐san’s talk in 10detail
Days
the merger
Days after
theafter
merger
20
Observed magnitude
27
27
20
Near Infrared
H bandi band
200 M
200 Mpc
22
4m
23
〜0.01Msun
24
1m
4m
25
space
8m
26
8m
27
0
5
10
15
Days after the merger
20
26
26
27
27
0
0 5
5 10
10 15
15 20
Days
the merger
Days after
theafter
merger
de
20 ugrizJHK-band light curves (in
Fig. 8.— Expected observed
z band
J band
1m to the NS merger event is set to be 200 Mpc. K correction is ta
21should follow up magnitudes
21
Mpc
200
We GW e200
vents ith telescopes l(5σ
arger 4m-­‐size
. MF
for w
wide-field
telescopes
withthan 10 min
exposure).
are taken or deduced from those of PTF (Law et al. 2009), CFHT
22
22 “4 m” and “space” limits are tak
NIR wavelengths (JHK bands),
de
20
〜0.004Msun
A Golden event: the short GRB 130603B 〜 kilonova/macronova candidate〜 Tanvir et al.,Nature,2013 Berger et al., ApJ, 2013 de Ugarte Pos(go et al, 2013
If this event is really “Kilonova/Macronova” ü  This could be direct evidence of compact binary merger hypothesis of short GRBs. ü  Macronovae will be promising EM counterpart of GWs. ü  A compact binary merger really produces 〜0.02Msun of r-­‐process elements Short GRB130603B
hjp://www.swin.ac.uk/burst_analyser/00557310/
Flux density (Jy @ 10 keV)
BAT−XRT data of GRB 130603B
BAT: Black −− XRT: WT: Blue; PC: Red
0.01
10−3
10−4
10−5
10−6
GRB prompt emission Swin BAT
10−7
10−8
10−9
10−10
3
Eγ ,iso = (2.1± 0.1) ×10 51 erg
2
T90 = 0.18 ± 0.02s
1
0
0.01
0.1
1
redshin z=0.356
10
100 1000 104 105
Time since BAT trigger (s)
106
107
Short GRB 130603B　de Ugarte Pos(go et al 2013
GRB anerglow(X-­‐ray)
Flux
Swin XRT
Near-­‐infrared excess Hubble Space telescope (me
A macronova associated with the short GRB 130603B? u Hubble Space Telescope imaging
Tanvir et al.,Nature,2013 Berger et al., ApJ, 2013 9 days aner the burst 30 days Op(cal The host galaxy
Near Infrared
macronova candidate
ing of the location of SGRB 130603B. The host is well resolved
26
Tanaka & KH 2013 27
0
26
26
20
27
27
r band
200 Mpc
20
21
1m
23
24
4m
25
22
23
24
25
Observed magnitude
21
Observed magnitude
Op(cal
22
8m
Days
the merger
Days after
theafter
merger
20
21
4m
25
0 5
5 10
10 15
15 20
Observa(on by 0 Hubble Space Telescope
5
10
15
Days after the merger
20
Observed magnitude
25
Obs
Obs
Obs
25
Near Infrared
22
H bandi band
200 M
200 Mpc
4m
1m
23
24
4m
25
space
8m
26
8m
27
0
20
21
5
10
15
Days after the merger
20
26
26
27
27
0
0 5
5 10
10 15
15 20
Days
the merger
Days after
theafter
merger
20 ugrizJHK-band light curves (in
Fig. 8.— Expected observed
z band
J band
1m to the NS merger event is set to be 200 Mpc. K correction is ta
21
200 Mpc
200 MF
magnitudes
for wide-field telescopes
(5σ with 10 min exposure).
More than 〜0.01Msun r-­‐process ejecta are ejected
If dynamical ejecta are dominant contribu(on to this bump.
Hotokezaka et al ApJL (2013) 22
24
SLy(Mej=0.02)
H4(Mej=0.004)
r
H
20
Magnitude (AB)
Magnitude (AB)
20
22
Observed point 24
26
Expected lightvurve 26
Mej〜0.02Msun 28
Expected lightcurve 28
Mej〜0.004Msun 30
30
1 be explained 10with Kilonova/Macronova 0.1
The observed 0.1
lightcurves can Produced by dRest-frame
ynamical ejecta 〜0.02Msun
days after
GRB 130603B
Rest-fram
GW – EM observa(on and r-­‐process
1, GW observa(on when/where we should follow up. 2, EM observa(on Total mass of ejecta can be es(mated. (r-­‐process element) 3, Collec(ng many events m
 r (r)
[mass/yr/galaxy]
In order to achieve this, precise understanding of nuclear hea(ng and opacity for various type of ejecta is important. Rebecca, Oleg, Shinya, and Masaomi’s talks
Summary
Detec(on of Electromagne(c counterparts will be important. They depend on baryon ouylows. 0.0001Msun – 0.01Msun of baryons will dynamically ejected with Velocity 0.1c – 0.3c. A Kilonova/Macronova candidate associated with a short GRB 13060Bhas discovered. Es(mated dynamical ejecta 〜0.02Msun. Future We should understand possible parameter space of ejecta mass, velocity, opacity, and hea(ng rate for various type of ejecta to es(mate ejecta mass.