重力波観測の現状とマルチメッセンジャーで探る重力波天体の物理

Status of Gravitational Wave Observations
andPhysics of GW Sources with Multi-messenger
Nobuyuki Kanda / Osaka City Univ.
KAGRA collaboration
3/2/2017, Chiba University

JGW-G1706300-v2

Basics of Gravitational Wave
Gravitational Wave (GW) is- distortion of Space-Time- predicted by General Relativity (GR) at 1915-1916- directly measured at 2015
Detection / Observation of GWs- by large base-length laser interferometer- with multi-detectors : two LIGOs +Virgo, KAGRA in near future- can extract information of source’s dynamical motion.
GW sources are- massive and compact objects : neutron star (NS), black-hole (BH)
- energetic motion : compact binary coalescence (CBC), supernova (SN)==> These events inevitably lead to high-energy astronomical
phenomena. Therefore, transient GWs may have multi-messenger
counterpart.
- Pulsar- Stochastic background (cosmological origin, astronomical origin, string, etc..)- unknown
2

Space-time and its wave
Gravity distorts the space-time !
Einstein Eq. 1
gµ R =RµTµ2
ct x y z
metric tensor“flat” space-time (Minkowski)

gµ

=

µ

=

1
0
0
0

0
1
0
0

0
0
1
0

“curved (distorted)” space-time

gµ

3

=

0 ct
0 x
0 y
1 z

No mass, No energy=> Flat space-time

Gravity caused by mass=> Distorted space-timeµsmall perturbation ‘h’ --> Waves
g µ = µ + hµ212hµ = 02
2
c t

Mass motion (non-spherical)=> Propagation of the distortion“Gravitational Wave” 4

GW radiation
Source- change (time derivative) of quadrupole moment of1
mass distribution2
Iµ = dV (xµ x
r
) (r)
µ
3
Amplitude- inversely proportional to the distance between source
2G ¨
and observer
hµ =
I
µ
4
Rc
Energy- total energy is given as : EGW
4... ...µ
G
>
<
I
I
µ
5c5

Electromagnetic Wave

Gravitational Wave

Electromagnetism

General Relativity（Maxwell Equation）（Perturbation of Einstein Equation）

Electric filed, Magnetic Field.
(Vector/Scalar potential)

Metric(distortion of the space-time)

TheoryFieldbinary連星= rotating dumbbell

CoupledChargeE, B (orA, )

Note:
5

四重極変形

.

hT T =

0 0
0 h+
0 h
0 0

0
h
h+
0

0
0
0
0

Quadrupole
deformation Mass (Quadrupole moment)
Electric Charge, Current

e,⌅i

1
137

..

.

m (I¨µ⇥ )運動方向、変形方向

2
Strengthe
非軸対称な物体の回転
Rotation
ofofnon.
=(=Coupling Constant
4 c
the interaction)
axisymmetricobjectCharacter.

G N m2c

10 39 for protons

speed of light

speed of lighttransverse

transverse

easily interact with materials,
can shieldvery small loss passing thematerials,
cannot shield.

Propagation of GW
Important characters:- Light speed- Transverse wave
Tidal force between
point masses

Perturbation h of the metric tensor g :

gµ

6

=

h is the strain of the spacetime.
2
12
c 2 t2µ+ hµhµ = 0Typical Sources of GW
Occasionally events :- Compact binary coalescence (CBC):
NS-NS, NS-BH, BH-BH
Neutron star : NS, Blackhole : BH

- Supernovae
BH Quasi-normal mode oscillation- Pulsar glitch
Continuous :- Pulsar rotation
BinaryStochastic Background- Early Universe
Cosmic string- Unresolvable astronomical origins(& Unknown...)7

How to detect GW
Important characters:- Light speed- Transverse wave
Tidal force between
point masses
Mirror

Perturbation h of the metric tensor g :Beam SplittergµLaser Light
MirrorInterferencecos( 2 pi 2dL /lambda)

8=

h is the strain of the spacetime.
2
12
c 2 t2µ+ hµhµ = 0Fundamental of the detection
Free mass = suspended mirrorxdistorted space-time

ﬂat space-time

Mirror

9

GW
light

t
x

Beam Splitter
Laser Light
MirrorInterferencecos( 2 pi 2dL /lambda)tMichelson Interferometer

Schematics of Laser Interferometric Detector
detector signal = GW * response + noises
GW

transfer functionof pendulum and servo

Seismic noise
Thermal noise(Brownian motion)change of the baseline length
Response of Fabry=Perot cavity

Radiation pressure noiseTime stamp
Fringe of light
Shot noise

A/D conversion
Electric circuit
Laser noise(intensity, frequency)
10

Electric noise

Quantizationnoise

signal (ti, Ni)

Global Network of GW detectors
GEO 600m

Virgo 3km

advanced LIGO
(Livingston) 4km(Hanford) 4km

advanced Virgo

LIGO India
TAMA 300m
CLIO 100m

3km

11Why we need many GW detectors ?
1. Localization of GW source direction
At least, Four or three detectors are necessary.
(depend on the relative direction and polarization of GW.)
We will use :- - arrival time difference- - amplitude ratio of detectors
GW150914 : ~600 deg^2
Average using
4 detectors : ~5 deg^2

天球

the celestial sphere

A-Bの時刻差から推定する到来方向
重力波検出器 A

GW detectors

4. Duty time for operation
12

B

C

2. Sky coverage
3. Survey volume

Guess by A-B

A-Cの時刻差から推定する到来方向

Guess by A-C
推定される重
Guessof the
力波源の方向arrivaldirection

Antenna Pattern (Response for source direction and polarization)
Interferometer’s antenna
pattern is widely spread as
almost ‘omni-directional’.
1.0
Cumulative Solid Angle / 4π

Declination~70% sky coverage by response > 0.5
sqrt(F+2 + Fx2), cumulative

z

( , )
zenith angle :azimuthal angle :

y
y

0.8

x
x

0.6
0.4
0.2

R.A.

Since0.0a single detector can not
0.2
0.4
0.6
0.8
1.0
resolve0.0the incident
direction
andAnttea Response
has(narrow) blind spots, we need
(目は悪いが、耳が悪いわけじゃ無い…^^;)
multi-detectors.

13z

GW source

90

SkyLIGO
coveragebydetector
network(Hanford)single detector

decl.[deg]zenith direction of detectors
LIGO Hanford
LIGO Livingston
VIRGO
LCGT

0

90
-12

0

0

-90

-12

-12

0
R.A.[hour]

14

12

KAGRA

90

decl.[deg]0R.A.[hour]decl.[deg]-90

Quadratic Sum : KAGRA+LIGO(Hanford)

120
R.A.[hour]

12

KAGRA will make important role in the network,with a complemental sensitivity map.

Sky coverage by detector network
LIGO x2 + VIRGO

zenith direction of detectors
LIGO Hanford
LIGO Livingston
VIRGO
LCGT

decl.[deg]90

KAGRA+LIGOx2+VIRGO
Quadratic Sum : KAGRA+LIGOx2+VIRGO

0

90

-12

0
R.A.[hour]

12decl.[deg]

-90

0

KAGRA

decl.[deg]

90

0

-90
15

-12

-12

0
R.A.[hour]

120
R.A.[hour]

12

KAGRA will make important role in the network,with a complemental sensitivity map.

Arrival Direction
CBC : ~10 deg2 resolution, at 160Mpc away, 5 detectors.

Fairhurst, arXivL1205.6611
7[degree]

[str]

20

3.0

2.5

⇥

average angular resolution δθ [degree]

Solid atangle
diffraction
limit networks of advanced
General(time delay based):
Figure 2. The
localization
accuracy
for face on BNS
160vsMPc
in various
3.5 degx (dt [msec])^(1/2),
NK 90%
2003 localization regions for sources from varioius points in thedetecors. The
ellipsescontain theRadiometry : ~3° @ 100Hz , 岡田雄太(2012, 修論)
sky. A ⇥ is plotted at points where the network would not confidently detect the system.
The
⇥
2
100
c
1
plots show the localization for six di↵erent networks: Hanford–Hanford–KAGRA–Livingston
diffraction limit
30
2f x(HHKL); Hanford–India–KAGRA–Livingston (HIKL); Hanford–Hanford–Livingston–Virgo
10(HHLV); Hanford–India–Livingston–Virgo (HILV);
Hanford–Hanford–KAGRA–Livingston–
3
Virgo (HHKLV); Hanford–India–KAGRA–Livingston–Virgo(HIKLV).
=0
2.0

1.5

Whole sky average
fitting : 3.5 [deg] (t [msec])1/2

1.0

Neutron star binary in our Galaxy
MACHO
fitting : 4.4 [deg] (t [msec])1/2

0.5

1

⇥

1 c
2f x

2

80
100

= 30
= 45
= 60

reasonably be an order of magnitude larger or smaller than the rate used here.
time resolution of event ΔT [msec][Hz]frequency increases significantly
The number of sources that will be detected by the various networks
16

0.1

0.2

0.3

0.4

0.5

LIGO and 1st GW observation
Laser
Interferometric
Gravitational-Wave
Observatory

Livingston (L1:4km)

Hanford (H1:4km)

O1 (Observation 1)
2015/9/18 - 2016/1/12
1100 hours
http://www.ligo.org/
17

PRL 116, 061102 (2016)

PHYSICAL REVIEW LETTERS

week ending
12 FEBRUARY 2016

(b)

(a)

FIG. 3. Simplified diagram of an Advanced LIGO detector (not to scale). A gravitational wave propagating orthogonally to thedetector plane and linearly polarized parallel to the 4-km optical cavities will have the effect of lengthening one 4-km arm and shortening
the other during one half-cycle of the wave; these length changes are reversed during the other half-cycle. The output photodetector
records these differential cavity length variations. While a detector’s directional response is maximal for this case, it is still significant formost other angles of incidence or polarizations (gravitational waves propagate freely through the Earth). Inset (a): Location andorientation of the LIGO detectors at Hanford, WA (H1) and Livingston, LA (L1). Inset (b): The instrument noise for each detector near19
the time of the signal detection; this is an amplitude spectral density,
expressed in terms of equivalent gravitational-wave strain

PRL 116, 061102(2016)

GW150914

FIG. 1. The gravitational-wave event GW150914 observed by the LIGO Hanford (H1, left column panels) and Livingston (L1, rightcolumn panels) detectors. Times are shown relative to September 14, 2015 at 09:50:45 UTC. For visualization, all time series are filteredwith a 35–350 Hz bandpass filter to suppress large fluctuations
20outside the detectors’ most sensitive frequency band, and band-rejectfilters to remove the strong instrumental spectral lines seen in the Fig. 3 spectra. Top row, left: H1 strain. Top row, right: L1 strain.

BH-BH in LIGO O1- O1 (Observational run 1) : Sep.18, 2015 - Jan. 12, 2016
GW150914, GW151226 : BBH (Binary Black Hole) mergers

21

arXiv:1606.04856

ppRemarks :the observed
GW events
in LIGO O1
GW150914
GW151226
LVT150120

22

Event

GW150914

GW151226

LVT151012

Signal-to-noise ratio
r

23.7

13.0

9.7

False alarm rate
FAR/yr 1< 6.0 ⇥ 10 7 < 6.0 ⇥ 10 7

0.37

7.5 ⇥ 10 8

7.5 ⇥ 10 8

0.045

> 5.3 s1.7sPrimary mass/Mmsource1Secondary mass/Mmsource2
Chirp mass
M source /M

36.2+5.2
3.8

14.2+8.3
3.7

23+18
6

29.1+3.7
4.4

7.5+2.3
2.3

13+45

28.1+1.8
1.5

8.9+0.3
0.3

15.1+1.4
1.1

Total mass
M source /M
Effective inspiral spin
ceffFinal mass
Mfsource /M

65.3+4.1
3.4

21.8+5.9
1.7

37+13
4

0.06+0.14
0.14

0.21+0.20
0.10

0.0+0.3
0.2

62.3+3.7
3.1

20.8+6.1
1.7

35+14
4

Final spin af

0.68+0.05
0.06

0.74+0.06
0.06

0.66+0.09
0.10

Radiated energy
Erad /(M c2 )3.0+0.5
0.4

1.0+0.1
0.2

1.5+0.3
0.4

Peak luminosity`peak /(erg s 1 )3.6+0.5
0.4 ⇥1056

3.3+0.8
1.6 ⇥1056

3.1+0.8
1.8 ⇥1056

Luminosity distanceDL /Mpc

420+150
180

Source redshift z

0.09+0.03
0.04

Sky localization
DW/deg2

230

p-valueSignificance> 5.3 sTh
overv
servinthe reevent
LVT1
resulttency
predi
rate oplicat
clude
the m
with
tunin
in thescribeparamof res
provi
mass
II.

Th
ford,
+500
+180
1000 500
440 190
are m
The i
+0.09
0.09+0.03
0.20
0.04
0.09
sage
chang
850
1600
ampli
arXiv:1606.04856Septe

Note : GW150914 in [Jy]PRL.116.061102

energy flux : 3.6 x 1056 erg/s(cf: total energy : ~ 3 Msolar ~ 5.4 x 1054 erg)
luminosity distance : 420 Mpc = 1.3 x 1027 cm
bandwidth : ~ 300Hz~ 5.7 x 1021 Jy
23

LIGO O2 run started

from Nov.30,
2016.
Scheduled as
6 months

24

https://www.ligo.caltech.edu/news/2016-11-30

Working
Underground...

Mine&Work&Style&
•
•
•
•
•
•

Work&cloths,&work&gloves,&work&boots&
Helmets&
Head&ligts&
Reﬂect&vests&
Oxygen&sensors&
Electric&bicyclesKAGRA

29~280 persons (>80 aﬃliations )▸ Underground▸ Kamioka mine

under the mountain▸ Silent and Stable▸ Cryogenic mirror▸ 20K▸ Sapphire substrate▸ 3km baseline▸ Schedule© ICRR, university of Tokyo▸ 2010 : Construction start▸ early 2016 : 1st operation in normal temperature▸ early 2018 : cryogenic operation

KAGRA 
•
•
•
•
•
•
•
•

茂住坑口!
Mozumi entrance!
980m(620m+360m)

rm
Ya m
3k
30°

Tilt: 1/300
Water drain point

Location of Center (BS)!
latitude: 36 .41°N, longitude: 137.31 °.!
Y arm direction: 28.31 deg. from the North.!
Height from the sea level : about 372m.
2 entrances for the experiment room.!
Center, Xend,Yend are inside more than 200m
from the surface of the mountain.!
Tunnel floor is tilted by 1/300 for natural waterdrainage. !
Height of the Xend: 382.095m.!
Height of the Yend: 362.928m.

rm
a
X m
3k

新跡津坑口!
New Atotsu entrance!
470m
303

KA

A
R
G

600m

3
by T.Uchiyama

Schedule

Budget and schedule

Calendar year

2010 2011 2012 2013 2014 2015 2016 2017 2018

Project start
Tunnel excavation
initial-KAGRA
iKAGRA run
baseline-KAGRA

Adv. Optics system and tests
Cryogenic system

Operation
BudgetLeading-edge…
iKAGRA- We had test run at March and April 2016.
ExcavationbKAGRA
Additional
budget- Advanced
Budgetfor operation? optics and cryogenic system are in progress.
Detector ~end of FY2017
Cryogenic
operation
Grants-in-aid for Sci.?
Data analysis
31

2 in JapanThe 26th Workshop on General Relativity and Gravitation

32

Shin‐Atotsu entrance(2017.1.7)

Tunnel excavation completed at March, 2014.

33

Photo : KAGRA tunnel, center corner34

at July 6, 2015
at Oct.
2014 of Oct.2014)(from almost
same28,
viewpoint

Central area (2017.1.7)

Pre‐stabilized laser (2016.9.20)

35

Cryostat for input test mass (2016.9.20)

input mode cleaner suspension system(2015.10.30)

TunnelDrive by Electric car
Upper floor
End room36

mid of the X-arm(almost) end of X-arm

Electronics hut

The electronics and computer hut
inside the KAGRA tunnel
37

DC power supply

frame writer -> transfer

I/O interface

Fiber connection
from/to the surface

Control room

Spool data system
38 in next room

Control room, surface building at Kamioka

Observation Scenario

Prospects for Observing and Localizing Gravitational-Wave
Transients with Advanced LIGO and Advanced Virgo
Living Reviews in Relativity, 19, (2016), 1(In next update of this documents.
KAGRA will appear in these figures.)39

optimal case with signal-to-noise ratio 8. Assuming galactic merger
events/Galaxy in average and known density of galaxies, LCGT is ex
detect about 10 events per year.
For case of black hole quasi-normal mode, we estimate the signa
ratio with assumption that 3% of mass will change as a radiation[6]parameter as 0.9 in this figure.
KAGRA

Sensitivity → Range

5 6 7

10

2

3

4 5 6 72

100
重力波の周波数 [Hz]3

4 5 6 7

1000

0.001

2

0

10

2

1000
6
5
4
3
2

1

2

10
10
mass of one star [Msolar](BH mass = 2M)

3

10

10Gyr 13Gyr

Look Back Time

1Gyr
100Myr3

0.01

10Gpc 100Gpc

aLIGO, aVirgo, KAGRAの目指す検出可能距離
ブラックホール準固有振動のみでの検出
6連星合体のインスパイラル波形のみでの検出
54両方の波形をつかった検出

10Mpc

-24

10

0.1

検出可能距離 [Mpc]

-23

10

1Gpc

1

LCGT detection range (VRSE-D)
for CBC| for BH QNM
SNR=3
|
SNR=3
SNR=8
|
SNR=8
SNR=100 |SNR=100

100Mpc-22

10

Cosmological Redshift : z

時空の歪み [1/√Hz]

aLIGO, aVirgo, KAGRAの目標感度帯

cf: Range (Sky Average)
Horizon (maximum distance)
Luminocity Distance

-21

10

1.4Msolar (Typical Neutron Star)

各検出器の目標感度
KAGRA
advanced Virgoadvanced LIGO
Einstein Telescope
10

-20

10

4

10

The 11th Asian-Pacific Regional
IAU Meeting 2011
太陽質量の10〜50倍付近は、
Figure 3. Detection
range
for
LCGT
for
optimal100
c direction and arran
現在の検出器の得意な質量NARIT Conference
Series,Vol. 1, ⃝2012
6
GW source. x-axis S.
is Komonjinda,
mass
oneY.starof binary,or halfeds.
of black hole t
Kovalev,and D. Ruﬀolo,
NK,
KAGRAofcollaboration
5

Thick solid and thick dashed lines
are corresponding
to signal-to-nois
1
10
100
1000
連星の質量
[太陽質量]
that is believed asLCGT
enough signatureclaim
thenetwork
detection.
and theto globalof40Remark : GW sources
Occasionally events :- Compact binary coalescence (CBC):
NS-NS, NS-BH, BH-BH
Neutron star : NS, Blackhole : BH

- Supernovae
BH Quasi-normal mode oscillation- Pulsar glitch
Continuous :- Pulsar rotation
BinaryStochastic Background- Early Universe
Cosmic string- Unresolvable astronomical origins(& Unknown...)41

Supernova (SN)Many process of SN possibly
radiate GWs- core bounce- convection- SASI- Jet
Neutrino, GW, EM will be emitted.
- Fruitful scenario of‘coincidence detection’- Multi-probes make it possible
to get newer knowledge anddeep understand of SN
mechanism.
Drawn by Y.Suwa
42

GW signal (example : Supernova)
Supernova (type II)
will emit shortduration GW (Burstwave) according tovarious processes in it.
Rotational Core
collapse (Bounce)
Convection
Proto-neutron starformation and gmode instability
Standing-AccretionShock Instability...
43

Dimmermeier at al.

Team SKE
SNe Theory(A05)
Y. Suwa・Provide time correlateddata, GW and neutrino
・Suggest signature signals
physical phenomenon

at Kakenhi New innovative area
「重力波天体」
Neutrino analysis(A03)
T. Kayano, Y. Koshio
M. Vagins
・R&D of EGADS detector
・Signal simulations withEGADS and SK

GW analysis(A04)
T. Yokozawa, M. Asano
N. Kanda
・KAGRA detector simulations

・Develop/Optimize GW analysis tools
・Prepare for realtime observation

44

12

neutrino

T.Yokozawa et al.,
ApJ., 811, 86 (12pp) 2015

GW

45

GW and neutrino analysis
for the dynamics of SNetiming analysis could
suggests that the core isstrongly rotating or not.

The Astrophysical Journal, 811:86 (12pp), 2015 October 1

Yokozawa et al.

Table 2The Various Scenarios’ GW Detection Efﬁciencies (GW eff.), Neutronization Neutrino Detection Efﬁciencies (Neutrino Eff.) for (1) EGADS or (2) GADZOOKS!,
Their Product, and the Pr Value for the 0.0π rad s−1 Model
Scenario
0.2 kpc, uniform
1.0 kpc, uniform
Galactic Center
Galaxy Dist.

GW Eff.(%)

Neutrino Eff.(%)

Detection Eff.(%)

Pr(%)

74.8
46.5
0.0
1.5

100.0(1)46.8(1)97.5(2)84.6(2)

74.8
21.9
0.0
1.5

0.0
20.8
L
0.2

Table 3The Various Scenarios’ GW Detection Efﬁciencies(GW eff.), Neutronization Neutrino Detection Efﬁciencies (Neutrino Eff.) for (1) EGADS or (2) GADZOOKS!,
Their Product, and the Pr Value for the 1.0π rad s−1 Model
Scenario
0.2 kpc, uniform
1.0 kpc, uniform
Galactic Center
Galaxy Dist.

GW Eff.(%)

Neutrino Eff.(%)

Detection Eff.(%)

Pr(%)

88.0
73.6
21.5
26.7

100.0(1)40.2(1)94.8(2)81.7(2)

88.0
29.5
20.4
24.7

98.4
80.0
75.3
76.2

et al. 2013). However, since MHD effects do not have a large
impact around the bounce, our conclusion will not be affectedeven if we include magnetic ﬁelds in our simulation for future
projects. Second, in this paper we employed one progenitor
model, s11.2 of Woosley et al. (2002) because it is well-studied
by a number of previous works. It should be noted that the
prompt convection depends on the structure of the progenitor
model. Therefore, to assess the robustness of the results
obtained in this study we need a more systematic study using
46 multiple progenitor models. In addition, we employed one

in Astrophysics Through Multi-messenger Observations ofGravitational Wave Sources” (Nos. 24103004, 24103005,
24103006, 25103511), JSPS postdoctoral fellowships forresearch abroad, MEXT SPIRE, and JICFuS. Numericalcomputations in this study were in part carried on XC30 at
CfCA in NAOJ and SR16000 at YITP in Kyoto University.
REFERENCES
Abbott, B. P., Abbott, R., Adhikari, R., et al. 2009, RPPh, 72, 076901

Observational Strategy for GW and Neutrino
Problems/Concerns:- Event must be near !
Typical range of GW and Neutrino detector for SN is a few-several 100Mpc.

- Our galaxy might be optical thick.
Therefore, …
- Keep duty time!
GW detectors may be key.

Never lose the chance of golden event !
- Inference of the direction by each detection is essential.
- We must develop the data analysis that can be done with a single event.
Advantages- omni-directional- ‘time machine’ likeIn both detector cases, we can analyze past records of event triggers/signals.

- (In Japan) SK and KAGRA has less uncertainty of arrival time difference.

47

Key issues- time series (time profile) of both GW and neutrino flux
- infer the SN direction

一
期
一
会

Personal question : How about IceCube for SN?

BAUM et al. I CE C UBE S UPERNO

SN @10kpc away

SignificanceMilky Way (center)no oscillation 0.5 s
normal hierarchy 0.5 s
inverted hierarchy 0.5 s

100Milky Way (edge)
LMC
SMC

0.1y−1 false trigger rate
10 SNEWS trigger thresholdinternal trigger threshold

preliminary
1

0

10

preliminary

42000

DOM Hits (20ms binning)

1000

Scenario A (NH)40000

Scenario B (IH)

38000
36000
34000
32000
30000

noise ﬂoor

28000

20

30
40
Distance [kpc]

50

60

70

No Oscillations

0

0.5

1

1.5

2

2.5

3

Time Post-Bounce [s]gure 1: Left: Expected significance versus distance assuming the Lawrence-Livermore model [9] for three oscillat
arXiv:1111.2731 (Proceedings of ICRC2011)
enarios. The significances are increased by neutrino oscillations in the star by typically 40% in case of an invererarchy. The Magellanic Clouds as well as the center and the edge of the Milky Way and various trigger thresho
e marked. For the Milky Way, the supernova progenitor distribution follows the prediction from [7], for the Magellaouds it is assumed to be uniform. Right: Expected rate distribution at 10 kpc supernova distance assuming normal a
48 hierarchies.
verseCBC (Compact Binary Coalescence)
Inspiralstrain

1

0

-1

-20ms

49

BH Quasi-normalmode2
重力波振幅 (大きさは距離に反比例)

Compact Stars :- Black-holes- Neutron Stars

Merger

-15ms

-10ms

時間 [秒]-5ms

time [sec]

0ms

5ms

CBC Waveform and Physics

phase

Inspiral(a few~1000sec,
depend on mass)

merger(~10msec)

ringdown(~100msec)

waveform

Post-Newton approx.
analytic waveform

Numerical relativity

Perturbation theory
of BH space-timefrequency(10Hz) ~ 1.5 kHza few kHzseveral kHz

Physics

50

mass of stars,
luminosity,
Tidal eﬀects,
arrival time
Viscosity,(with multi-detectors,…
direction, polarization,phase, orbit-> NS’s E.O.S.
inclination, distance)(In case ofHyper-massive
NS is formed,)
EOS,
hyperon,…

BH mass
BH spinTesting GR

After merger of NS-NS, NS-BH

46:48 (15pp), 2012 February 10

Metzger & Berger

tions). Because merger counterparts
Jet ISM Shock (Afterglow)
obtaining a spectroscopic redshift
Optical (hours days)
Radio (weeks years)
nson et al. 2010), in which casealaxyEMis thefollow-ups
most promising means
Ejecta ISM ShockRadio (years)
hift.
In cases of NS-NS
uish two general strategies for conobs
and
NS-BH,
ts. One approach is to search for a
GRB(t ~ 0.1 1 s)
EM trigger, either
in real time or at
Electro-magneticg., Finn et al. 1999; Mohanty et al.
Kilonova
radiationpredicted
can bepromising for counterparts
Optical (t ~ 1 day)
idence with the GW chirp, such as
expected.
jMerger Ejecta
bursts (SGRBs). Unfortunately, mostTidal Tail & Disk Wind
arts (none of which have yet beenv ~ 0.1 0.3 c
occur hours to months after coalesBH
d arrival time of the GW signal willcase the additional sensitivity gained
gnificantly reduced. For instance, if
wn only to within an uncertainty ofl show is the case for optical (radio)
ber of trial GW templates that mustfactor ∼104 –106 than if the merger
Figure 1. Summary of potential electromagnetic counterparts of NS–NS/
conds, as in the case of SGRBs.
& Berger,
ApJ 746:48(2012)
NS–BH mergers discussedMetzger
in this paper,
as a functionof the observer angle,
51
ch is the primary focus of this paper,

BH-BH52

Origin of Massive Black-holes ?
Stars as like our sun cannot form such heavy BH…
- Population III
stars ?
Metal less stars that may be the ‘first stars’ of the universe- Dynamical
formation ?
runaway merger of BHs- Primordial BH?
BH formed directly at early universe5330%+%30%solar%mass%BHs
Interes1ng&target&for&three&reasons:Nakano%Talk
30M_sun-30M_su

Inspiral&and&ringdown&phases&
have&roughly&equal&SNRs,&so&provides&good&test&of&GR
If&popula1on&III&stars&(formed&at&
redshios&5\10)&exist,&these&might&be&a&substan1al&frac1on.&

Perhaps&we&will&detect&several&y Kanda, the LCGT collaboration, arXiv:1112.3092
of&them&in&the&ﬁrst&aLIGO&data&
Similar SNR for the inspiral and ringdown phas
run&O1,&this&September!
Osaka&20.6.2015

viewgraph edited by Bruce Allen : (Personal) summary of new, novel, and interesting resultspresented at this workshop
54
at GWPAW2015 Osaka, June 201518

MNRAS 456, 1093–1114 (2016)

doi:10.1093/mnras/stv2624

The detection rate of inspiral and quasi-normal modes of Population III
binary black holes which can confirm or refute the general relativity
in the strong gravity region
Tomoya Kinugawa,1‹ Akinobu Miyamoto,2 Nobuyuki Kanda2
and Takashi Nakamura1
1 Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan

2 Department of Physics, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan

Accepted 2015 November 5. Received 2015 October 17; in original form 2015 May 26

55

Using our population synthesis code, we found that the typical chirp mass defined by(m1 m2 )3/5 /(m1 + m2 )1/5 of Population III (Pop III) binary black holes (BH–BHs) is ∼30 M⊙
with the total mass of ∼60 M⊙ so that the inspiral chirp signal as well as quasi-normal mode
(QNM) of the merging black hole (BH) are interesting targets of KAGRA. The detection rate of
the coalescing Pop III BH–BHs is ∼180 events yr−1 (SFRp /(10−2.5 M⊙ yr−1 Mpc−3 ))([fb /(1+ fb )]/0.33)Errsys in our standard model, where SFRp , fb and Errsys are the peak value ofthe Pop III star formation rate, the binary fraction and the systematic error with Errsys = 1
for our standard model, respectively. To evaluate the robustness of chirp mass distribution
and the range of Errsys , we examine the dependence of the results on the unknown parameters and the distribution functions in the population synthesis code. We found that the chirp
mass has a peak at ∼30 M⊙ in most of parameters and distribution functions as well as
Errsys ranges from 0.046 to 4. Therefore, the detection rate of the coalescing Pop III BH–
BHs ranges about 8.3-720 events yr−1 (SFRp /(10−2.5 M⊙ yr−1 Mpc−3 ))([fb /(1 + fb )]/0.33).
The minimum rate corresponds to the worst model which we think unlikely so that unless(SFRp /(10−2.5 M⊙ yr−1 Mpc−3 ))([fb /(1 + fb )]/0.33) ≪ 0.1, we expect the Pop III BH–BHs
merger rate of at least one event per year by KAGRA. Nakano, Tanaka & Nakamura show that
if signal-to-noise ratio (S/N) of QNM is larger than 35, we can confirm or refute the generalrelativity (GR) more than 5σ level. In our standard model, the detection rate of Pop III BH–
BHs whose S/N is larger than 35 is 3.2 events yr−1 (SFRp /(10−2.5 M⊙ yr−1 Mpc−3 ))([fb /(1 +Downloaded from http://mnras.oxfordjournals.org/ by guest on December 20

ABSTRACTWindow as a function of binary masses
Example : LIGO O1

2

Horizon distance [Mpc]

100
8
7
6
5
4

GW150914

3NS-BH
1.4-20 Msun : 409Mpc

GW151226
NS-BH
1.4-10 Msun: 337Mpc

10
8
7
6
5
4

200

3
2

(In another word, thismight be a ‘bias’…)

500

NS-NS
1.4-1.4 Msun: 162Mpc

1
8
7
6
5
5 6 7

56

1000
400
300

Detector opens
window forparticular mass
ranges.

m2 [Msolar]

2

LVT151012

12

3

4 5 6 710
m1 [Msolar]

23

4 5 6 7100

2

Summary
Welcome to the observational era!
We need more more more events !!!
Multi-messenger observation
for deep understanding of GW sources.
i.e. dynamical motion and mechanism, origin, etc.

GW observation itself still attractive for the study offundamental physics.

57