すばるとTMTによるマルチメッセンジャー天文学
Mul6-messenger Astronomy with Subaru and TMT

田中雅臣 (東北大学)
Masaomi Tanaka (Tohoku University)their spectrum falls steeply with energy, allowing
astrophysical neutrinos to be more easily identified at higher energies. The muon-neutrino as-

IceCube can robustly identify astrophysi
trinos at PeV energies, for individual neat several hundred TeV, an atmospheri

New era of mul6-messenger astronomy

Fig. 1. Event display forneutrino event IceCube170922A. The time at which a
R ES E A RC H | R E S EA R C H A R T I C LE
DOM observed a signal isreflected in the color of the hit,
lower limit of 183 TeV, depending only weakly on
trophysical spectrum, together with simulated
cannot be excluded. Electromagnetic observations
with(25).
darkdata,
blues
fortoearliest
hits
the assumed astrophysical energy spectrum
was used
calculate theprobability that a
are valuable to assess the possible association of
The vast majority of neutrinos detected
neutrino
the observed
track energy and zenitha single neutrino to an astrophysical source.
and byyellow
for atlatest.
Times
IceCube arise from cosmic-ray interactions within
angle in IceCube is of astrophysical origin. This
Following the alert, IceCube performed ashown
relativeto thesignalness
first of the event complete analysis of relevant data prior to
Earth’s atmosphere. Although atmosphericneu- areprobability,
the so-calledtrinos are dominant at energies below 100 TeV,
was reported to be 56.5% (17). Although
31 October 2017. Although no additional excess
DOM hit (14),accordingto the track
their spectrum falls steeply with energy, allowing
IceCube can robustly identify astrophysical neuof neutrinos was found from the direction of TXS
reconstruction,
andearlierandastrophysical neutrinos to be more easily
identitrinos at PeV
energies,
for individual
neutrinos
0506+056 near the time of the alert, there arefied at higher energies. The muon-neutrino asat several hundred TeV, an atmospheric origin
indications at the 3s level of high-energy neutrino
later times are shown with thesame colors as the first andFig. 1. Event display forlast times, respectively. The
neutrino event IceCube170922A. The time at which a
total time the event took to
DOM observed a signal iscross the detector is ~3000 ns.
reflected in the color of the hit,with dark blues for earliest hits
The size of a colored sphere isand yellow for latest. Times
shown are relative to the first
proportional to the logarithm
DOM hit according to the trackof the amount of lightreconstruction, and earlier andlater times are shown with theobserved at the DOM, withsame colors as the first andlarger spheres corresponding
last times, respectively. The
total time the event took toto larger signals. The total
cross the detector is ~3000 ns.
Figure 2. Joint, multi-messenger detection of GW170817 and GRB170817A. Top: the summed GBM lightcurve for sodium iodide (NaI) detectors
1,
2,
and
5
for
charge recorded is ~5800 photoelectrons. Inset is an overhead perspective view of the even
The size of a colored sphere isGravita6onal waves(GW170817) 10-100 deg2

High-energy neutrinos(IceCube-170922A) 1-10 deg2

Abbo$+17

are m1 Î (1.36, 2.26) M: and m 2 Î (0.86, 1.36) M:, with total+0.47
mass 2.820.09 M: , when considering dimensionless spins withconsistenthereafter), the measured component masses are
m1 Î (with1.36,a zenith angle 5:7þ0:50"0:30 degrees below the horizon.
1.60) M: and m 2 Î (1.17, 1.36) M:, and the total mass is3

Utsumi, MT, Tominaga+17

Downloaded from http://science.sciencemag.org/ on July 12, 2018

GRB170817A between 10 and 50 keV, matching the 100 ms time bins of the SPI-ACS data. The background estimate from Goldstein et al. (2016) is overlaid in red.
proportional to the logarithm
Second: the same as the top panel but in the 50–300 keV energy range. Third: the SPI-ACS lightcurve with the energy range starting approximately at 100 keV andconsistent with a zenith angle 5:7þ0:50"0:30 degrees below the horizon.
of the amountof light
with a high energy limit of least 80 MeV. Bottom: the time-frequency map of GW170817 was obtained by coherently combining LIGO-Hanfordand LIGOobserved at the DOM, with
Livingston data. All times here are referenced to the GW170817 trigger time T0GW .
larger spheres corresponding
to larger
signals.
The 90% credible intervals(Veitch et al. 2015; Abbott et al.
magnitudes up to 0.89 (high-spin prior, hereafter).
When
the The total
recorded
2017e) for the component masses (in the m1 . m 2 convention)(low-spinprior, is ~5800 photoelectrons. Inset is an overhead perspective view of the event. The best-fitting track direction is shown as an arrow,dimensionless spin prior is restricted to -0.05 charge

IceCube+18

pixel, using detected photons with energy of 1 to 300 GeV in a 2° by 2°
Fig. 2. Fermi-LAT and MAGIC observations of IceCube-170922A’s
region around TXS0506+056. The map has a pixel size of 0.02° and was
location. Sky position of IceCube-170922A in J2000 equatorial coordinatessmoothed with a 0.02°-wide Gaussian kernel. MAGIC data are shown as
overlaying the g-ray counts from Fermi-LAT above 1 GeV (A) and the signal
signal significance for g-rays above 90 GeV. Also shown are the locations ofsignificance as observed by MAGIC (B) in this region. The tan squarea g-ray source observed by Fermi-LAT as given in the Fermi-LAT Third
indicates the position reported in the initial alert, and the green square
Source Catalog (3FGL) (23) and the Third Catalog of Hard Fermi-LAT
indicates the final best-fitting position from follow-up reconstructions (18).
Sources (3FHL) (24) source catalogs, including the identified positionally
Gray and red curves show the 50% and 90% neutrino containment regions,coincident 3FGL object TXS 0506+056. For Fermi-LAT catalog objects,
respectively, including statistical and systematic errors. Fermi-LAT data aremarker observations
sizes indicate the 95%
positional uncertainty of the source.
shown as a photon counts map in 9.5 Fig.
years ofin units of counts
2.dataFermi-LAT
andperMAGICofCLIceCube-170922A’s

location. Sky position of IceCube-170922A in J2000 equatorial coordinates

pixel, using deregion aroundMul6-messenger astronomy with Subaru and TMT• Synergy with gravita6onal wave astronomy• Synergy with neutrino astronomy

2

s a BNS as the source of the gravitational-wave sigas the total masses of known BNS systems are been 2.57 M and 2.88 M , with components between
and ⇠1.6 M [47]. Neutron stars in general have prey measured masses as large as 2.01 ± 0.04 M [48],reas stellar-mass black holes found in binaries in ourxy have masses substantially greater than the compos of GW170817 [49–51].
ravitational-wave observations alone are able to meathe masses of the two objects and set a lower limit
heir compactness, but the results presented here do not
ude objects more compact than neutron stars such as
k stars, black holes or more exotic objects [52–56].
detection of GRB 170817A and subsequent electronetic emission demonstrates the presence of matter.
eover, although a neutron star–black hole system is not
d out, the consistency of the mass estimates with theamically measured masses of known neutron stars in
ries, and their inconsistency with the masses of known
k holes in galactic binary systems, suggests the sourcecomposed of two neutron stars.

2017 Aug 17

The ﬁrst GW detec6on fromneutron stars merger

Electromagne6c wave
Observa6ons
DATA

t the time of GW170817, the Advanced LIGO detecand theAdvancedVirgo
detector were in observing
LIGO
Scien>ﬁc
Collabora>one. The maximum distances at which LIGO-Livingston
and Virgo Collabora>on, 2017, PRL
LIGO-Hanford could detect a BNS system (SNR = 8),
wn as the detector horizon [58–60], were 218 Mpc and

FIG. 1. Time-frequency representations [57] of data containing

Coulter+17, Soares-Santos+17, Valen>+17,
Arcavi+17, Tanvir+17, Lipunov+17

Movie: Utsumi, MT, Tominaga+17
Tominaga, MT, Morokuma+18

W170817, asc). AlthoughSun, the firstd the narrowobservations
Collaboration

campaign ofational wave
survey with2), which isof the 8.2m
st among theis the mostis paper, weproperties of
e correct the1, and all the

Wide-ﬁeld survey with Subaru/HSC
No other transient within 40 Mpc distance

300o

30o

300o

30o

Tominaga,
MT, Morokuma
et al. 2018
Fig. 1. Pointing map for GW170817
overlaid
on the probability
map(LALInference v2.fits.gz; Abbott et al. 2017c). The white contour represents
the 90% credible region. Circles represent the field-of-view of HSC, changing their face color with an order of observation. Observations have been

Cri6cal for the future events with larger distances

Arcavi+17, Cowperthwaite+17,
Diaz+17, Drout+17,Evans+17,
Kasliwal+17,Pian+17, Smar$+17,
Tanvir+17, Troja+17,Utsumi,
MT+17, Valen>+17Signature of r-process nucleosynthesis
16

InfraredOpen issues•• Enough event rate?
elements are• Whichproduced?

Ejecta mass is universal?

Observed magnitude

17

18

g
r
i
z
J
H
K

-17

-16

-15

19

-14

20

-13

21

Op6cal

-12

22
0

5
10
Days after GW170817=> Need more observa6ons(diﬀerent masses, angles, and environments)-11
15

Absolute magnitude

Iden6ﬁca6on of “kilonova”

Power of GW-EM mul6-messenger observa6ons

Astrophysics

Origin of heavy elements
Origin of rela>vis>c jets
Popula>on of black holes

Cosmology

Hubble constant
Speed of gravita>onal wave
Gravity theory

Nuclear physics

High-density equa>on of stateGW astronomy in the TMT era

We are here
h$ps://wiki.gw-astronomy.org/OpenLVEM/Telecon20190815
Figure 2: The planned sensitivity
evolution and observing runs of the aLIGO, AdV and
KAGRA detectors over the coming years. The colored bars show the observing runs,
with achieved sensitivities in O1 and in O2, and the expected sensitivities given by the
大神さん
data in Fig. NS-NS
1 for future(~150
runs. Thereis significant
uncertainty
in the start and end times- S190425z:
Mpc,
7500
deg2)
of the planned observing runs, especially for those further in the future, and these could- S190426c:
NS-NS
or BH-NSorwhat
noise
(~380
1100
deg2)
move forward
or backwards
relative tois shown
above.Mpc,
Uncertainty
in startorfinish dates is represented by shading. We do anticipate that the break between O3 and- S190814bv:
BH-NS (~270 Mpc, 23 deg2)
O4 will last at least 18 months. Any extension of O3 would lead to a corresponding

Several events of interest so far

S190425z: 2nd candidate of NS merger (~150 Mpc)

GW170817: 30 deg2

h$ps://gracedb.ligo.org/superevents/S190425z/

No convincing counterpart was iden6ﬁed so fare.g., Hosseinzadeh+19

GW observa6ons with KAGRA
Simula>ons with GW150914

GW150914 with future detectors

9

Subaru/HSC

LIGO+Virgo+KAGRA

Figure 3. The 90% credible areas of one individual signal. The upper panel shows theglobal localisation
over theanalysis)root-mean-square sensitivity patterns of the Hanford andLocaliza6on
area (real6me
added
2 in quadrature. The two yellow areas mark the locations
LIGO:Livingston
600 deg2detectors=> 300 deg
with the highest antenna response while signals from sources located in the dark
2
LIGOblue+ Virgo:5.5
degregions are strongly suppressed. Only the largest areas are shown, as design
LIGOsensitivity+ Virgo +runs
KAGRA:
deg2 would be indistinguishable. The lower panels showwith 1.2
3+ detectors
the central region in greater detail and illustrate the di↵erences between 3, 4, andhttps://arxiv.org/pdf/1703.08988.pdf
5-detector set-ups, which continuously shrink thearea while remaining centred on

Kilonova @ 200 Mpc (assuming GW170817)
g
r
i
z
J
H
K

17

Caveats:
Op6cal emission
may be suppressed
for equatorial
viewing angles(see Kawaguchi,
Shibata, MT 18)

Observed magnitude

18
19

-20
-19
-18
-17

20
-16
21
-15
22
-14
23
Subaru z(1 min)

24
25

-13

0

-12
5
10
Days after GW170817

15

Absolute magnitude

16

Mul6-messenger astronomy with Subaru and TMT• Synergy with gravita6onal wave astronomy• Synergy with neutrino astronomy

Galac6c supernova!
~ 1 event per 100 yr(人類の宝)SN neutrino(~ 10 MeV, Kamiokande)“Astronomie+Populaire”++
by+Camille+Flammarion+(Paris,+1884)

Not always brightCCSN simulation and Multimes

pre-arranged follow-up programme
play in securing the rise of the opti

4 E X T R E M E LY N E A R B Y
4.1 Neutrino

An extremely
nearbyopens
Fainter
than
20CCSNmag:phenomenon. An example is the de
~30
%from
probability
arisingsilicon burning (Odrz

are generated by nuclear processe
captures, as well as thermal process
pair annihilations (e.g. Misiaszek, O
Localiza6on~ 2015).
3 degThe be
Patton & Lunardini
yield O(10)MeV neutrinos, which(with
SK-Gd)
to several kpc (Odrzywolek et al. 2
KamLAND (Asakura et al. 2016).
about the pre-collapse progenitor (advanced warning of an imminent c

Nakamura+16

4.2 Gravitational waves

Figure 9. Detection prospects and strategies of the plateau signal of Galac-Origin of high-energy comic ray in the Universe

1015 1017 1019 1021 (eV)High energy protons => neutrino

with dark blues for earliest hits
and yellow for latest. Times
shown are relative to the first
DOM hit according to the trackreconstruction, and earlier andlater times are shown with thesame colors as the first andlast times, respectively. The
total time the event took to
cross the detector is ~3000 ns.
The size of a colored sphere is
proportional to the logarithmof the amount of lightobserved at the DOM, withlarger spheres corresponding
to larger signals. The total
charge recorded is ~5800 photoelectrons. Inset is an overhead perspective view

Detec6on of high-energy neutrino with IceCube

IceCubeIceCube-170922: High-energy neutrino (~ 300 TeV)=> Flaring blazar in Fermi/LAT dataE S EA R C H A R T I C LE

V, depending only weakly on
hysical energy spectrum (25).
y of neutrinos detected byosmic-ray interactions within
Although atmospheric neut at energies below 100 TeV,
steeply with energy, allowing
nos to be more easily identigies. The muon-neutrino as-

trophysical spectrum, together with simulateddata, was used to calculate the probability that aneutrino at the observed track energy and zenith
angle in IceCube is of astrophysical origin. This
probability, the so-called signalness of the event(14), was reported to be 56.5% (17). Although
IceCube can robustly identify astrophysical neutrinos at PeV energies, for individual neutrinos
at several hundred TeV, an atmospheric origin

cannot be excluded. Electromagnetic observations
are valuable to assess the possible association ofa single neutrino to an astrophysical source.
Following the alert, IceCube performed acomplete analysis of relevant data prior to
31 October 2017. Although no additional excess
of neutrinos was found from the direction of TXS
0506+056 near the time of the alert, there areindications at the 3s level of high-energy neutrino

The IceCube collabora>on+ 2018enith angle 5:7þ0:50"0:30 degrees below the horizon.

Downloaded from http://science.sciencemag.org/ on July 12, 2018

y for
Cubeat which agnal isr of the hit,earliest hitst. Timeso the firsto the trackearlier andwn with thefirst andvely. The
took to~3000 ns.
d sphere islogarithm
htM, withespondinge total~5800 photoelectrons. Inset is an overhead perspective view of the event. The best-fitting track direction is shown as an arrow,consistent with a zenith angle 5:7þ0:50"0:30 degrees below the horizon.

Blazar TXS 0506+056
Fig. 2. Fermi-LAT and MAGIC observations of IceCube-170922A’s
location. Sky position of IceCube-170922A in J2000 equatorial coordinates
overlaying the g-ray counts from Fermi-LAT above 1 GeV (A) and the signal
significance as observed by MAGIC (B) in this region. The tan squareindicates the position reported in the initial alert, and the green squareindicates the final best-fitting position from follow-up reconstructions (18).
Gray and red curves show the 50% and 90% neutrino containment regions,
respectively, including statistical and systematic errors. Fermi-LAT data are

Caveats: it is known that blazars are NOT major sources for thediﬀuse neutrino ﬂux => supernovae? Other sources?? Aartsen+17

pixe
regio
smo
sign
a g-r
Sou
Sou
coin

al telescopes, the limit corresponding to the deepest observation is shown, while for the othercombined. The limit for the Swift BAT is purely based on the observation taken 100 s after there Sect. 4.2.1) and hence applies to prompt gamma-ray emission. Follow-up observations were
he neutrino triplet.

Iden6fying supernovae as neutrino sources

alization and consider simthe event selection of thetection of 600 astrophysicalorthern sky. For this calcuneutrino spectrum down toy threshold. If we were only
re the astrophysical flux has), we would expect the delarge number of expectedfrom the broad, inclusive
ram which aims to includensient neutrino sources thatcal neutrino flux. The cosely describes the redshifteutrino sources, like CCRBs (Wanderman & Piraner et al. 2015) which howger redshifts. We simulated
ormation rate of Madau &each source the probability
r of neutrinos after
applySinglet
w-up program. We find thatrino is located atDoublet
a median.
Tripletource detected with multihow bright the individual

諸隈さん

Event rate ~ Star forma>on ratez = 0.02

z = 0.06

z=1

Aartsen+17, A&A
Fig. 8: Probability of detecting a neutrino source within a certain red-Distancea populationSNof brightness
shift. The Redshik
figure was generated by simulatingtransient
neutrino sources with a density of 10 6 Mpc 3 yr 1 distributed in redz ~to1the star-formation7rate
Gpc
mag
shift according
and normalized to26
producethe detected
astrophysicalneutrino flux.
Sources
detected with19
onlymag
one
z
~
0.06
280
Mpc
single neutrino are on average far away (median redshift of 1.1), whilesources detectedwith three or more 90
neutrinos
nearby.
z ~ 0.02
Mpcmust be located 17
mag

8m telescope!!
1m telescopeNeutrino observa6ons in the TMT era
Localiza6on with IceCube-Gen2=> lower contamina6on

Up
going

IceCubeJ. van Santen
Gen2

Down
going

PoS

erformance of 240 m “sunflower” geometry.
Thecollabora>onleft panel2017
IceCubeSummary• New era of mul6-messenger astronomy• Gravita>onal waves, neutrinos, and electromagne>c waves• Gravita6onal wave sources• First observa>ons of EM counterpart• Hint of heavy element produc>on in NS merger• Next Galac6c supernova• High-energy neutrino sources• Flaring blazar• But there should be other sources

Subaru/TMT will play crucial role in mul6-messenger astronomy(wide ﬁeld search => deep spectroscopy)