Multi-Messenger Studies ofCompact Binary Merger- コンパクト連星合体のマルチメッセンジャー研究 -Masaomi Tanaka(National Astronomical Observatory of Japan)
田中 雅臣
in collaboration with
Kenta Hotokezaka, Yuichiro Sekiguchi, Kenta Kiuchi,
Masaru Shibata, Koutaro Kyutoku, Shinya Wanajo

supernova

binaryneutron	  starneutron	  star	  merger

binarySi,	  Fewhite	  dwarf

black	  holeAu,	  Ag?
(r-­‐process)supernova

planetary	  nebulaO,	  Mg,	  CaAu,	  Ag?
(r-­‐process)

H,	  C,	  N
Ba,	  Pb(s-­‐process)asympto2c	  giant	  branchHHHred	  supergiantlow	  mass	  starhigh	  mass	  starInterstellar	  medium

Images:	  NASA,	  ESA,	  JPL-­‐Caltech,	  CXC

Multi-Messenger Studies ofCompact Binary Merger• Mass ejection and nucleosynthesis• Electromagnetic wave signals• Toward multi-messenger astronomy

New astronomy with gravitational waves
Supernova

Compact binary merger(neutron star/black hole)< 10-100 kpc~0.01 event/ 1 yr

< 200 Mpc
~30 (0.3-300) events/ 1 yr

2017 - Advanced LIGO (US)- Advanced Virgo (Europe)- KAGRA (Japan)

KAGRA

spectral sensitivity (strain per root Hz)-15

BH-BH-16(10 6Mo ) at

-17-18Andersson10LISA

-19

BH
-B

H(z=110 6+10-20-21Mo ) at

z=1

BH-BH (10Mo) at 100 Mpc
NS-BH (10Mo) at 200 Mpc-22

NS-NS at 200 Mpc-2320 Mpc: 0.03 events/yr-24
200 Mpc: ~ 30 events/yr-25-6-5-4-3-2-1
0
1
23gravitational-wave frequency (log10 f /1Hz)

GEO600LIGO
VIRGO
AdLIGOET45

1 deg~ 100 galaxies / 1 deg2(< 200 Mpc)

SDSS

GW alert error

e.g. 6 deg x 6 deg(not box shape in reality)
No electromagnetic counterpart
No gravitational wave astronomy
GW detection

EM search

1 deg
Source identification“Multi-messenger” astronomyEM signature from NS merger

strophysical Journal, 746:48 (15pp), 2012 February 10

specific stellar populations). Because merger counterparts
redicted to be faint, obtaining a spectroscopic redshift
allenging (cf. Rowlinson et al. 2010), in which caseroscopy of the host galaxy is the most promising means
taining the event redshift.
s important to distinguish two general strategies for conng EM and GW events. One approach is to search for asignal following an EM trigger, either in real time or att-processing stage (e.g., Finn et al. 1999; Mohanty et al.
). This is particularly promising for counterparts predicted
cur in temporal coincidence with the GW chirp, such as-duration gamma-ray bursts (SGRBs). Unfortunately, mostpromising counterparts (none of which have yet been
endently identified) occur hours to months after coales.6 Thus, the predicted arrival time of the GW signal willn uncertain, in which case the additional sensitivity gained
this information is significantly reduced. For instance, if
me of merger is known only to within an uncertainty ofurs (weeks), as we will show is the case for optical (radio)
erparts, then the number of trial GW templates that mustarched is larger by a factor ∼104 –106 than if the merger
is known to within seconds, as in the case of SGRBs.
second approach, which is the primary focus of this paper,
M follow-up of GW triggers. A potential advantage in thisis that counterpart searches are restricted to the nearby
rse, as determined by the ALIGO/Virgo sensitivity range
hift z ! 0.05–0.1). On the other hand, the large error• On-axis short GRB• Extended emission

Metzger & Berger

Jet ISM Shock (Afterglow)
Optical (hours days)
Radio (weeks years)

Ejecta ISM ShockRadio (years)

GRBobs(t ~ 0.1 1 s)(~25% of short GRB)

Kilonova

Optical (t ~ 1 day)

• Off-axis radio/opticalafterglow

jMerger Ejecta
Tidal Tail & Disk Windv ~ 0.1 0.3 c

BH• Radioactive emission(kilonova, macronova)

Need mass ejection

Metzger& Berger2012
Figure 1. Summary of potential
electromagnetic
counterpartsof NS–NS/NS–BH mergers discussed in this paper, as a function of the observer angle
θobs . Following the merger a centrifugally supported disk (blue) remains aroundthe central compact object (usually a BH). Rapid accretion lasting !1 s
powers a collimated relativistic jet, which produces a short-duration gamma
ray burst (Section 2). Due to relativistic beaming, the gamma-ray emission
is restricted to observers with θobs ! θj , the half-opening angle of the jetNon-thermal afterglow emission results from the interaction of the jet withMass ejection
from NS mergers

M ~ 10-3 - 10-2 Msun

Hotokezaka+13

see Kiuchi-san’s talkNucleosynthesis in NS merger
npne=
Ye =
np + nn
np + nn

The Astrophysical Journal Letters, 738:L32 (6pp), 2011 September 10
The Astrophysical Journal Letters, 738:L32 (6pp), 2011 September 10

the total radioactive heating rate per unit mass, ⟨Q⟩, mass number ⟨A⟩, and temperature ⟨T ⟩ (all mass-averaged over the ejecta) for thend 1.2–1.5 M⊙ (dotted lines) NS mergers. 0.35
e is available in the online journal.)
0.35

1.35–1.35Mo NS

0.3

0.3

1.35–1.35Mo NS

1.35–1.35Mo NS

1.35–1.35Mo NS

0.25

Mass fraction

Mass fraction

0.25

0.02 0.03

0.2

0.04

0.05

0.2

0.15
0.15
0.10.10.05
0.05

Goriely+1100

0.25 0.32
0.32 0.39
0.39 0.46
0.46 0.53
0.53 0.60
0.60 0.68
0.68 0.015 0.021
0.25
0.021 0.027
0.027 0.033
0.033 0.039
0.039 0.045
0.0450.051
0.051 -0.35
0.35

dance distributions of the ejecta from 1.35–1.35 M⊙ (squares) and 1.2–1.5 M⊙ (diamonds) NS mergers as functions of atomic mass. The
1.20–1.50M NSo the solar r-abundance distribution (dotted circles).

Ye

1.20–1.50M NS

r-process elements in stars
1.0
CS 22892 -052 data
SS r-process abundances
SS s-process abundances

PtOsBa0

DyCe

NdGdr-process

YbSm– 0.5

PbIr

Er

HflogAstrophys. 2008.46:241-288. Downloaded from www.annualreviews.org
tional Astronomical Observatory of Japan on 12/15/14. For personal use only.

0.5– 1.0HoEuLaPr– 1.5AuTbTmLuThs-process– 2.0U–2.55060

70

Atomic number
Figure 1080

90

Sneden+2008

Ye = 0.09 0.14 0.19 0.24 0.34 0.44

-310Wanajo & Janka 2012).

Recent progress-4

abundance

1010-5Generalrelativity
with-610
neutrino transfer
10-7

See Sekiguchi-san’s poster-8
10(No37)150
050
100200250mass number-2

10

solar r-abundancemass-averaged

10-3-4abundancemass fraction

1010-5
10-6
10-7
10-8

050

100
150
mass number

200

250

4. RADIOACTIVE HEATThe r-processing ends a few 100 mof merger. The subsequent abundan
decay, fission, and α-decay are follow
after themerging;higherYe the resulting radioa
evant for kilonova emission. Figure 5 dral evolutions of theν heating rates forries (top-left) and those mass-average
a comparison purpose, the heating raabundances with the solar r-process p
decaying back from the initial compo
separation energies of 2 MeV(A ≥ 90i
The r-processused in Hotokezaka et al. 2013a; Tan0shown by a black-solid line in each
10alsodashed line indicates an analytical app
10 −1.3by q̇analytic≡2×10t 0.4(in units-10.10.2
0.3
10time in day, see, e.g., Metzger et al. 20
are the same as the upper panels, bu-2
10 to q̇analytic .
Overall, each curve reasonably foll1 day. After this time, the heating-3
10a few radioactivities and becomes hig
Ye . Contributions from the ejecta of-4
10 erally unimportant after ∼ 1 day.
0.0
0.1
0.3turns0.4to be0.5
heating
for Ye0.2= 0.34sign
10 days because Yofe the β-decays from0= 10.8 Sekiguchi+2014
yr; see Figure 4, bottom,
10T1/2
Wanajo,89103

Amount of r-process elements

Event rate

GW

RNSM ~ 100 event/Myr/Galaxy= 10-4 event/yr/Galaxy

NS-NS merger rate
Within 200 Mpc~ 30 events/yr(~0.3-300)

Ejection per event
Mej(r-process) ~ 10-2 Msun
M(Galaxy, r-process) ~ Mej(r) x (RNSM x tG)~ 10-2 x 10-4 x 1010 ~ 104 Msunr-process elements in the early Universe
2[Eu/Fe]1

Data from
Suda+08,14. Milkyway

0

Dwarfogalaxy-1-2

figure courtesy of Yutaka Hirai-4-3 -2 -1[Fe/H]

0see Hirai-san’s poster (No 65)(e.g., Argast+04, Matteucci+14, Tsujimoto & Shigayema 2014)

Multi-Messenger Studies ofCompact Binary Merger• Mass ejection and nucleosynthesis• Electromagnetic wave signals• Toward multi-messenger astronomyEM signature from NS merger

strophysical Journal, 746:48 (15pp), 2012 February 10

specific stellar populations). Because merger counterparts
redicted to be faint, obtaining a spectroscopic redshift
allenging (cf. Rowlinson et al. 2010), in which caseroscopy of the host galaxy is the most promising means
taining the event redshift.
s important to distinguish two general strategies for conng EM and GW events. One approach is to search for a
signal following an EM trigger, either in real time or at
t-processing stage (e.g., Finn et al. 1999; Mohanty et al.
). This is particularly promising for counterparts predicted
cur in temporal coincidence with the GW chirp, such as-duration gamma-ray bursts (SGRBs). Unfortunately, mostpromising counterparts (none of which have yet been
endently identified) occur hours to months after coales.6 Thus, the predicted arrival time of the GW signal willn uncertain, in which case the additional sensitivity gained
this information is significantly reduced. For instance, if
me of merger is known only to within an uncertainty ofurs (weeks), as we will show is the case for optical (radio)
erparts, then the number of trial GW templates that mustarched is larger by a factor ∼104 –106 than if the merger
is known to within seconds, as in the case of SGRBs.
second approach, which is the primary focus of this paper,
M follow-up of GW triggers. A potential advantage in thisis that counterpart searches are restricted to the nearby
rse, as determined by the ALIGO/Virgo sensitivity range
hift z ! 0.05–0.1). On the other hand, the large error• On-axis short GRB• Extended emission

Metzger & Berger

Jet ISM Shock (Afterglow)
Optical (hours days)
Radio (weeks years)

Ejecta ISM ShockRadio (years)

GRBobs(t ~ 0.1 1 s)(~25% of short GRB)

Kilonova

Optical (t ~ 1 day)

• Off-axis radio/opticalafterglow

jMerger Ejecta
Tidal Tail & Disk Windv ~ 0.1 0.3 cBH• Radioactive emission(kilonova, macronova)

Metzger& Berger
2012
Figure 1. Summary of potential
electromagnetic
counterpartsof NS–NS/
NS–BH mergers discussed in this paper, as a function of the observer angle
θobs . Following the merger a centrifugally supported disk (blue) remains aroundthe central compact object (usually a BH). Rapid accretion lasting !1 spowers a collimated relativistic jet, which produces a short-duration gamma
ray burst (Section 2). Due to relativistic beaming, the gamma-ray emission
is restricted to observers with θobs ! θj , the half-opening angle of the jet
Non-thermal afterglow emission results from the interaction of the jet withng ofinedo
pholatterd fisnuclei
manns: thed theinsky). For
duced
rates
from

Radioactive-powered
emission2653
Transientsfrom compact object mergers

NSm1
erg

er

10

100days

Supernova

Metzger+10

Figure against
1. Radioactive
heating rate per unit=>massopticalĖ in NS merger
ejectaThick
gamma-rays
emission
due to the decay of r-process material, calculated for the Y e = 0.1 ejecta

“kilonova”
Li & Paczynski 98
Metzger+10

Timescale

Luminosity

tp

10

1 day41L

energydepositionenergydeposition

M0.01M

1042 erg s 1

1/2

M
0.01M

v
0.2c

1/2

Opacity of r-process elementsκ ~ 10 cm2 g-1(Kasen+13, MT & Hotokezaka 13)

v
0.2c

1/2

10

1/2

0.1 cm2 g 1

1/2

10

1/2

0.1 cm2 g 1

Bound-boundopacity of Fe

600,000 b-b transitions
for 90 elements
MT & Hotokezaka 2013

characteristic velocity is below 10,000 K, when the dominant ionizati
are no longer triply ionized ions. A detailed discussion is presented inAppendix B.

etzger et al. 2010), by a factor of about 100. As a result,
metric light curve becomes fainter and the timescale

1000-1κ (cm g )100

2r-process
FeNSM-all
NSM-Febound-boundopacity

101
0.1
0.01
0.001

5000

10000

15000

Wavelength (A)Mass absorption coefficient κ at v = 0.1c in the models NSM-all and NSM-Fe as a function of wavelength (t = 3 days after the merger). Inh ejecta, the opacity is higher than in Fe-rich ejecta by a factor of about 100 around the center of optical wavelengths (∼5000 Å).
rsion of this figure is available in the online journal.)

Higher opacity by factor of 100!
6wavelengths, there are possible absorption troughs, which result from Y i, Y ii, andbe result from the incompleteness of the line list in the NIR wavelengths. Must beEquation of state => EM emission
4210

1.2 + 1.5
1.3 + 1.4

toy model
NSM-all
APR4 (soft)
SoftEOSH4 (stiff)(ug bands
Radiusof
1.35 deep
Msunobser
NS-1

UVOIR Luminosity (erg s )lengths (iR = far
11.1below
km tForkmlarge-2R=13.610 Msun
Stiff EOS
be smaller
41
10Hawaii Teltelescope/
3.6 deg2 anthe limitinbright mod40
10at the firstservations
faint mod10-3 Msun
below theMT & Hotokezaka 2013posure).
39
10To cover1
10class telesc
aru/Hyper
Days after the merger
and Large
Fig. 7.— Bolometric light curves for realistic models (Table 1).
2008; LSS
expectedemissionNSof modelswith a =>soft brighter
EOS APR4 (red)iswide field
Softer The
EOS(smallerradius)
emissionbrighter than that with a stiﬀ EOS H4 (blue). For the soft EOS
We showAPR4, the light curve does not depend on the mass ratio, while forunequal mass
BJ2012f (kHz)3.5

3Observational constraints
on EOS
2.52EM signal

1012R1.8 (km)

3.51
3
0.1
2.5

2
0.01
0.13

0.14

0.15

0.16 0.17
Mtot/2R1.35

0.18

0.19

0.2

small R

Hotokezaka et al.

equal massunequal mass
BJ201240.1

14

BH-NS models
Peak frequency

10APR4
SLy
ALF2
H4MS1

f (kHz)1

NS-NSmodels
Massejection

Mej/10-2Msun

Mejecta/10

Mej/10-2-2
Msun

Msun

The Astrophysical Journal Letters, 778:L16 (5pp), 2013 November 20

10

GW signal

0.01
0.13
10

APR4
ALF2
H4MS1
ALF2(7,0.5)
H4(7,0.5)
MS1(7,0.5)

0.14

small R

Mtot/2R
Figure 2. Ejecta masses as a function of the compactness of the neutron star, which is defined by GM /2R
tot

0.1512 0.16
0.17
MNS/R1.35

0.18
140.19R1.6 (km)1.35 c2 and GM /R
2NS
1.35 c for NS–NS and BH–NS models,

respectively. Left panel: NS–NS models. Each point shows the ejecta mass for the equal mass cases. Error bars denote the dispersion of the ejecta masses due tothe various Q. Right panel: BH–NS models. The filled and open symbols correspond to the models with (Q, χ ) = (3–7, 0.75) and (7, 0.5), respectively. The blue
shaded region in each panel shows the ejecta masses allowed in order to reproduce the observed near-infrared excess of GRB 130603B, 0.02 ! Mej /M⊙ ! 0.07 andBauswein & Janka 2012
0.02 ! Mej /M⊙ ! 0.1 for the NS–NS and BH–NS models, respectively. The lower and( upper bounds are imposed by hypothetical high- and low-heating models,respectively.
Hotokezaka, Kyutoku, MT+ 2013
Hotokezaka, Kiuchi, Kyutoku 2013
(A color version of this figure is available in the online journal.)

FIG. 13 (color online). The frequency of the Fourier spectrum peapanels) and M ¼ 1:6M (lower panels) with a given EOS for m ¼ 2
we plotted all the data (equal-mass and unequal-mass data) using thH LETTER

Kilonova candidate in GRB 130603B

AB magnitude

Mej ~ 0.02 Msun => soft EOS (if NS merger)

X-ray flux (erg s–1 cm–2)

Time since GRB 130603B (d)he redshifts of the afterglow21 and the host galaxy22 were1
10
to be z 5 0.356.
10–11
proposed signature of the merger of two neutron stars or a
X-ray
21r and a black hole is the production of a kilonova (someF606W
ermed a ‘macronova’ or an ‘r-process supernova’) due to22
F160W
f radioactive species produced and initially ejected during
process—in other words, an event similar to a faint, short23
nova6–8. Detailed calculations suggest that the spectra of
10–12
va sources will be determined by the heavy r-process ions24
he neutron-rich material. Although these models10–13 arem being fully realistic, a robust conclusion is that the optical
25
greatly diminished by line blanketing in the rapidly expanwith the radiation emerging instead in the near-infrared
10–13
NIR
sourcebeing produced over a longer timescale than would other26
case. This makes previous limits on early optical kilonova
nsurprising23. Specifically, the NIR light curves are expected27
oad peak, rising after a few days and lasting a week or more
rame. The relatively modest redshift and intensive study of28
10–14
3B made it a prime candidate for searching for such a kilonova.
ed of the location of the burst with the NASA/ESA Hubble
29
cope (HST) at two epochs, the first ,9 d after the burst
105
106
104
nd the second ,30 d after the burst (epoch 2). On each occaTime since GRB 130603B (s)e orbit integration was obtained in both the optical F606Wm) and the NIR F160W filter (1.6 mm) (full details of the imag- Figure 2 | Optical, NIR and X-ray light curves of GRB 130603B. Left axis,
otometric analysis discussed here are given in Supplemen- optical and NIR; right axis, X-ray. Upper limits are 2s and error bars are 1s. Theation). The HST images are shown in Fig. 1; the key result is optical data (g, r and i bands) have been interpolated to the F606W band anddata have been MT+2013
interpolated to the F160W band using an average
difference frames (right-hand panels), whichHotokezaka,
provide clear the NIR
Kyutoku,r a compact transient source in the NIR in epoch 1 (we note spectral energy distribution at ,0.6 d (Supplementary Information). HST
urce was also identified24 as a candidate kilonova in indepen- epoch-1 points are given by bold symbols. The optical afterglow decays steeply,0.3 d and isIoka
modelled2014
here as a smoothly broken power law
seealso Takami,
Nozawa,s of our data on epoch 1) that seems to havedisappearedby after the first(dashed blue line). We note that the complete absence of late-time opticald is absent to the depth ofKisaka,
the data in theoptical.Takami emission
56Ioka,2014 also(Kisaka-san’sposterNodecay23)component. The
Ni-drivenplaces a limit on any separate

Amount of r-process elements
Event rate

GW

RNSM ~ 100 event/Myr/Galaxy= 10-4 event/yr/Galaxy

NS-NS merger rate
Within 200 Mpc~ 30 events/yr(~0.3-300)

Ejection per event
Mej(r-process) ~ 10-2 Msun

EMM(Galaxy, r-process) ~ Mej(r) x (RNSM x tG)~ 10-2 x 10-4 x 1010 ~ 104 Msun
“Testable” scenario for r-process nucleosynthesis

Multi-Messenger Studies ofCompact Binary Merger• Mass ejection and nucleosynthesis• Electromagnetic wave signals• Toward multi-messenger astronomy

1. Numerical simulations

RAPID COMMUNICATPHYSICAL REVIEW D 90, 041502(R) (2014)

CAL RELATIVITY …

higher Ye=> lower A

Wanajo+14
Kiuchi+14

Effect of neutrinos of the density, magnetic-field strength and magnetic-field lines for H4B15d70 at t − tmrg ≈ 0.0 ms
EMbe panel). tmrg Magnetized
NS of the(middle =>panel),and emission
at t − tmrg ≈ 38.8canms (rightis a time when the amplitude
imum. The left, brighter/bluer
middle, and right panels show the configuration
just after the onset ofmass
the merger, for=> Additionalurrounded by an accretion torus, respectively. In each panel, the white curves are the magnetic-field
ejection?
(e.g., Just+14,Metzger+14,epresents the magnetic
fields stronger
than 1015.6 G. In the middle panel,
the yellow, green, and dark

(Kiuchi-san’stalk)
10Kasen+14)
face of 1014 , 1012 , and 10
g=cm3 , respectively. In the right panel,
the light anddark blue are the1010 g=cm3 , respectively.

Numerical relativity + radiative transfer (ν+EM)2. Nuclear physics– 10 –

solarabundance

Eichler+2014

Same NS merger modelwith different fission fragment distribution

Fig. 1.— Final abundances of the integrated ejecta around the second and third peak for a NSM

see Shibagaki-san’s poster (No 31)
6Rosswog et al. 2013; Korobkin et al. 2012) at a simulation time t = 10 s, employing the FRDM

3. EM counterpart search
Kiso 1.05m Schmidt telescope

MOU between
Japanese Opt/IR group
andLIGO/Virgo collaboration
193

201

208

2 deg
215

223

230

237

244251

Toward wider field of view
Current Status of -Conceptual
DesignStudy
Tomo-e camera http://www.ioa.s.u-tokyo.ac.jp/tomoe/index.html

The 1st generation wide-field CMOS camera
480 mm35mm Full HD CMOS sensor•
x 84 chips• Efficient observation f

Large FOV Ω (20 deg2)

KWFC
530 mm

KWFC-CCD

190 Mpixels
760
MB/exposure
Surveypower = fAΩ

Photo plate

Total sky coverage 20 deg2
ĭ500 mm = ĭ8.7 deg
vignetting 0.44mag

ĭ225 mm = ĭ3.9 deg
vignetting free area
Institute of Astronomy, The University of Tokyo(PI: Shigeyuki Sako)sensor / package area = 0.3GW alert error box
e.g. 6 deg x 6 deg

Kiso/Tomo-e
9 deg
Kiso/CCD
2 deg

Subaru/ Hyper Suprime-Cam

104 CCDs~ 900 Megapixel
2 GB/image~300 GB/night

8.2m
3t !

3mGW alert error box
e.g. 6 deg x 6 deg

Kiso/Tomo-e
9 deg
Kiso/CCD
Subaru/HSC
2 deg
1.5 deg
8m-class
50-100 Mpc telescope

400 Mpc

Numerical simulation

C: Sekiguchi,Shibata+EM astronomy

GW astronomy

SubaruKAGRA“Multi-messenger”
astronomy+Nuclear physics+Galaxy evolution

Origin of r-process elements
Neutron star radius (High-density EOS)