コンパクト天体—Time-domain & Multi-messenger—

仏坂健太 (東京大学)

A very large fraction of the astronomical community contributed to this survey through thealmost 900 excellent science, activity, program, and state of the profession white papers and throughactive engagement in town hall meetings. The program laid out in this report represents a collective vision
for the future and will require the engagement of a broad community to advance.

Astro 2020 - コンパクト天体 Astro2020よりAstro2020で採択されているサイエンスプログラムのうち、
FIGURE
S.1 Timeline for the recommended medium and large programs and projects. The starting
point of each, indicated by the logos, shows the projected start of science operations for missions andobservatories,or the start date of the program. The boxes on the right show the survey’s three broad
コンパクト天体関係は2020年代にオペレーションがある
science themes, and the placement of the logos to the left of the boxes indicate which activities address
the2030年代にかけて継続的に観測主体で進展する。
indicated theme.

コンパクト天体：2030年代サイエンスゴール
宇宙の物質の運命：星の進化と終焉の統一
超新星・GRBと恒星進化の統一、元素の起源、
ブラックホールの統計(1万個の世界)

極限物理の実験場：一般相対論・標準モデルを超えたい
Hulse -Taylor，重力波，Sgr A*に続く更なる検証，
最高E宇宙線・ニュートリノ

新種の自然現象の探究
クエーサー，パルサー, GRB, X線連星, 1987Aニュートリノバースト
潮汐破壊，FRB，BBH，キロノバなど10年スケールで増えてきた2020-30年代の3つの軸
1. Time-domain: 突発天体から新たな天体の同定し、新しいサイエンスを展開する。多波長が極めて重要。
2. Multi-Messenger Time-domain: 重力波天体、ときどき電磁波対応
天体が見つかる。30年代後半にはニュートリノ天体も出てくる。
3. Survey & Characterization: 天文サーベイデータからコンパクト天体を発見し、質量などを詳細に決定する。（系外惑星の方法と類似）

2020-30年代の3つの軸
1. Time-domain: 突発天体から新たな天体の同定し、新しいサイエンスを展開する。多波長が極めて重要。
2. Multi-Messenger Time-domain: 重力波天体、ときどき電磁波対応
天体が見つかる。30年代後半にはニュートリノ天体も出てくる。
3. Survey & Characterization: 天文サーベイデータからコンパクト天体を発見し、質量などを詳細に決定する。（系外惑星の方法と類似）detect 10 million transient events with sub-arcsecond positional accuracy, sending triggers to telescopes
around the globe and in space, to follow up with observations at other wavelengths and to correlate withobservations using other messengers. This revolution is extending to a broader range of wavelengths
outside the traditional optical and gamma ray bands. The Roman satellite will carry out a near-infrared
supernova survey that will also likely discover new classes of infrared transients. Roman’s microlensing
survey will allow characterization for the first time of the mass function of the majority of neutron stars
and black holes in the galaxy. The extended Roentgen Survey with an Imaging Telescope Array(eROSITA) is carrying out the first all-sky X-ray survey since the Roentgen Satellite (ROSAT) in theearly 1990s. Additionally, there is a tremendous increase in the number of international radio facilities
searching for radio transients (e.g., CHIME, the Australian Square Kilometre Array Pathfinder (ASKAP),
MeerKat).

Time-domain (光赤外)•明© Brad Cenko

多様な可視光突発天体が明らかになりつつある。(PTF, Pans,
ASAS-SN -> ZTF)

これらと恒星・連星進化、宇宙の物質進化が統一されていく。
• 重力波・ニュートリノ突発天体とのシナジーが約束されている。
•

今後、10年
Vera Rubin や Roman、サーベイ体

暗 積が急激に増加
既知の種族は大量に見つかる。
• 希少なもの、暗いもので新しい種•
FIGURE 2.16 Types of optical transients, distributed in peak brightness and characteristic timescale, adapted from
Cenko (2017). New wide-field optical surveys expected to come online this decade will surely populate this diagramwith other transient exotica. SOURCE: Adapted by E. Quataert, with permission from Springer Nature: S.B. Cenko,
20187, Astrophysics: The true nature of transients, Nature Astronomy 1:0008, https://doi.org/10.1038/s41550-0160008, copyright 2017.

短命

長命

PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION
2-32族の現象にも期待。

Time-domain

detect 10 million transient events with sub-arcsecond positional accuracy, sending triggers to telescopes
around the globe and in space, to follow up with observations at other wavelengths and to correlate withobservations using other messengers. This revolution is extending to a broader range of wavelengths
outside the traditional optical and gamma ray bands. The Roman satellite will carry out a near-infrared
supernova survey that will also likely discover new classes of infrared transients. Roman’s microlensing
survey will allow characterization for the first time of the mass function of the majority of neutron stars
and black holes in the galaxy. The extended Roentgen Survey with an Imaging Telescope Array(eROSITA) is carrying out the first all-sky X-ray survey since the Roentgen Satellite (ROSAT) in theearly 1990s. Additionally, there is a tremendous increase in the number of international radio facilities
searching for radio transients (e.g., CHIME, the Australian Square Kilometre Array Pathfinder (ASKAP),
MeerKat).

新しい種族の突発天体を見つける：新しい領域へ(時間・波長)© Brad Cenko

速い天体
c

l
ica

pt
o
,

Ne

V
rU

c
0.1

a

N

r
ea

,
1c
0
.0
V0

l

ca
pti

c

1
0.0

o

U

FIGURE 2.16 Types of optical transients, distributed in peak brightness and characteristic timescale, adapted from
Cenko (2017). New wide-field optical surveys expected to come online this decade will surely populate this diagramwith other transient exotica. SOURCE: Adapted by E. Quataert, with permission from Springer Nature: S.B. Cenko,
20187, Astrophysics: The true nature of transients, Nature Astronomy 1:0008, https://doi.org/10.1038/s41550-0160008, copyright 2017.

PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION

Promising target: Shock Breakout

Jet or Shock Breakout? GRB 06
104 – 105 s

early
UV/optical

Band + blackbody model improves the spectral fi
been claimed as evidence for thermal emission.
al. (2014) have also found evidence for thermal
several other bursts. In fact, Axelsson & Borgo
have recently suggested that most bursts musbroadened thermal component, because in theobserved bursts, the full width half maximum ofRc
Irwin & Chevalier 15
peak is narrower than is physically possible forRadioradiation. Although prompt thermal radiation
105 – 106 s
afterglow
τd'tionally indicated, the physical origin of this emn© Eran Ofek
unclear. One possible source of thermal
X-rays is
cocoon, although the flat early light curve of G
Ek
• 衝撃波が星を突き破る際の光and GRB (典型的にはsoft
100316D is hard X,
to UV)
explain in thiset al. 06; Starling et al. 2012; see also Ramirez• 爆発を引き起こした星が何者かわかる
2002). Another possibility is that the blackbody• 突発天体のフロンティアの一つ
produced at the transparency radius in a dissipa

UV 突発天体
UVサーベイ：•discovery spaceが広い•

Shock breakout の観測に最適•

キロノバ の初期の信号を捉える•

後期は可視・赤外で明るいはずで、Followup観測をやりやすい•

ULTRASAT: near UV, FoV~200 deg2, ~22 mag (AB), cadence min ~ months•

Dorado: 1000 deg2 every 3hr, ~20 mag (AB)•SIBEX: Wide-field X-ray + far UV follow-up.

•

LAPYUTA: 10 arcmin, 23 mag

Time-domain

detect 10 million transient events with sub-arcsecond positional accuracy, sending triggers to telescopes
around the globe and in space, to follow up with observations at other wavelengths and to correlate withobservations using other messengers. This revolution is extending to a broader range of wavelengths
outside the traditional optical and gamma ray bands. The Roman satellite will carry out a near-infrared
supernova survey that will also likely discover new classes of infrared transients. Roman’s microlensing
survey will allow characterization for the first time of the mass function of the majority of neutron stars
and black holes in the galaxy. The extended Roentgen Survey with an Imaging Telescope Array(eROSITA) is carrying out the first all-sky X-ray survey since the Roentgen Satellite (ROSAT) in theearly 1990s. Additionally, there is a tremendous increase in the number of international radio facilities
searching for radio transients (e.g., CHIME, the Australian Square Kilometre Array Pathfinder (ASKAP),
MeerKat).

新しい種族の突発天体を見つける：新しい領域へ(時間・波長)速い天体
遅い電波天体FIGURE 2.16 Types of optical transients, distributed in peak brightness and characteristic timescale, adapted from
Cenko (2017). New wide-field optical surveys expected to come online this decade will surely populate this diagramwith other transient exotica. SOURCE: Adapted by E. Quataert, with permission from Springer Nature: S.B. Cenko,
20187, Astrophysics: The true nature of transients, Nature Astronomy 1:0008, https://doi.org/10.1038/s41550-0160008, copyright 2017.

PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTIONE DSA-2000:
DESIGNAND DEVELOPMENT
今後
電波突発天体も出てくる© Gregg Hallinan•

電波は通常、突発天体を追加観測に用いられてきた (FRBなど短いものを除く)

tween the• DSA-2000 and other current (small squares) and planned
しかし、2030年代には、サーベイ速度が現在の100-1000倍！！！
d-frequency
Square Kilometre Array; ASKAP- Australian SKA• おそらく、相対論的な突発天体が一網打尽

2020-30年代の3つの軸
1. Time-domain: 突発天体から新たな天体の同定し、新しいサイエンスを展開する。多波長が極めて重要。
2. Multi-Messenger Time-domain: 重力波天体、ときどき
電磁波対応天体が見つかる。30年代後半にはニュートリ
ノ天体も出てくる。
3. Survey & Characterization: 天文サーベイデータ（Gaiaなど）やコンパクト天体を発見し、質量などを詳細に決定する（系外惑星の方法と類似）。

EM Counterpart Discovery
Timeline )重力波の電磁波対応天体(キロノバ
Abbott et al. ApJ, 2017
Gravitational waves(2017 Aug 17.5)
T=0Near Infrared
T = 11h 36m

X-rays
T = 9 days

Off-axis jet?

Delayed Arrival of X-rays and Radio

Gamma-rays
T = 1.7 seconds

OpticalT = 10h 52m

Ultraviolet
T = 15 hours

Radio
T = 16 days

Kilonova
Afterglow
Extremely faint!
uJy @3 GHz)
outflows
andthe ISM)(radioactivity of r-process elements) (shock between(~15キロノバのサイエンス•

重元素の起源を理解できる鍵•

同定するだけで、重力波による宇宙論が進むLesson from GW170817
60
Sr ii

Sr ii
blueshift

いる。

•1. 膨張速度0.1c G.程度。
Burbidge, E. M.,~
Burbidge,
R., Fowler, W. A. & Hoyle, F. Synthesis of40

1

F [10 17 erg s 1 cm 2 Å ] + offset

50Blackbody + Sr ii
Blackbodythe Elements in Stars. Rev. Mod. Phys. 29, 547–650 (1957).

•2. 中分散で良い
Siegel, D. M., Barnes, J. & Metzger, B. D. Collapsars as a major source

1.5 days

30 offsets

2.5 days20
3.5 days10

4.5 days

1

Residual F [10 17 erg s 1 cm 2 Å ]decades later30 . However, no spectroscopic confirmation of the compositionof neutron stars has ever been made. The identification here of• 可視領域には構造が少ない。
an element that could only have been synthesised so quickly under an• Sr II?
extremeneutronflux, provides the first direct spectroscopic evidence
P-Cygniが見えるが、かなり広がってthat neutron stars comprise neutron-rich matter.

of r-process elements. Nature 569, 241–244 (2019).
•3. Lattimer, J. M., Mackie, F., Ravenhall, D. G. & Schramm, D. N. The
decompression of cold neutron star matter. Astrophys. J. 213, 225–233• (1977).
4. Eichler, D., Livio, M., Piran, T. & Schramm, D. N. Nucleosynthesis, neutrino bursts and gamma-rays from coalescing neutron stars. Nature 340,
126–128 (1989).
5. Freiburghaus, C., Rosswog, S. & Thielemann, F.-K. R-Process in NeutronStar Mergers. Astrophys. J. Lett. 525, L121–L124 (1999).
6. Ji, A. P., Frebel, A., Simon, J. D. & Chiti, A. Complete Element Abun• dances of Nine Stars in the r-process Galaxy Reticulum II. Astrophys. J.
830, 93 (2016).
7. Metzger, B. D. et al. Electromagnetic counterparts of compact object
mergers powered by the radioactive decay of r-process nuclei. Mon. Not.
R. Astron. Soc. 406, 2650–2662 (2010).
8. Barnes, J. & Kasen, D. Effect of a High Opacity on the Light Curves ofRadioactively Powered Transients from Compact Object Mergers. Astrophys.
peakJ. 775, 18 (2013).
9. Tanvir, N. R. et al. A ‘kilonova’ associated with the short-duration -ray
burst GRB 130603B. Nature 500, 547–549 (2013).
10. Abbott, B. P., Abbott, R. & et al. GW170817: Observation of Gravitational
Waves from a Binary Neutron Star Inspiral. Physical Review Letters 119,161101 (2017).
11. Pian, E. et al. Spectroscopic identification of r-process nucleosynthesis
in a double neutron-star merger. Nature 551, 67–70 (2017).
12. Smartt, S. J. et al. A kilonova as the electromagnetic counterpart to a
gravitational-wave source. Nature 551, 75–79 (2017).

狭い波長域の分光データは使いにくい。

可視から近赤外までカバーしたデータが極めて有用だった（VLT X-shooter）

今後、可視ピーク~1日, T~5000K, λ<8000Aに構造がない天体を探せば良い。

3
-3
3
-3
3
-3
3
-3

1.5 days
2.5 days
3.5 days
4.5 days
4000

5500

7500
10500
Observed wavelength [Å]

Watson et al 19

14500

20000

Figure 4 | Spectral series of AT2017gfo 1.5–4.5 days after the merger. DataM

~ 17 mag at 40 Mpc (GW170817)-> 21 mag at 200 Mpc (O4 2022~)-> 22 mag at 330 Mpc (O5 2025~?)-> 25 mag at >1 Gpc (３G 203?)E0 = 0.052). The fiducial model (wind) is also shown as a dash-do
the dynamical ejecta and slow models are ⇡ 10 day and 70 day, resp

元素の特定に向けて：準黒体から輝線期へ
60
Sr ii

Sr ii

50

blueshift10

2.5 days20
3.5 days1

4.5 days

3
-3
3
-3
3
-3
3
-3

1.5 days
2.5 days
3.5 days
4.5 days
4000

5500

7500
10500
Observed wavelength [Å]

14500

20000

Figure 4 | Spectral series of AT2017gfo 1.5–4.5 days after the merger. Data
are shown in grey and have been smoothed slightly. A model (solid red lines)
consisting of a blackbody (blue dotted lines) with P Cygni profiles (red transparentfill) for the Sr lines is shown. The rest (black) and observed (blue) positions of themodel’s Sr lines are shown, with the blueshift indicated by arrows. Green dottedlines show the Gaussian emission profiles added to ensure the overall continuum
is not biased. A vertical offset has been applied to each spectrum for clarity, withzero flux indicated by the dashed horizontal line segment. Bottom panels show theresiduals between model and data.

L /fi [erg s 1 ]1.5 days

30 offsets

39

[µm]

100

Nd II, ne = 1.6 · 104 cm 3 , Te = 4500 K

1. Burbidge, E. M., Burbidge, G. R., Fowler, W. A. & Hoyle, F. Synthesis of
the Elements in Stars. Rev. Mod. Phys. 29, 547–650 (1957).
2. Siegel, D. M., Barnes, J. & Metzger, B. D. Collapsars as a major sourceof r-process elements. Nature 569, 241–244 (2019).
3. Lattimer, J. M., Mackie, F., Ravenhall, D. G. & Schramm, D. N. The
decompression of cold neutron star matter. Astrophys. J. 213, 225–233
38(1977).
4. Eichler, D., Livio, M., Piran, T. & Schramm, D. N. Nucleosynthesis, neutrino bursts and gamma-rays from coalescing neutron stars. Nature 340,
126–128 (1989).
5. Freiburghaus, C., Rosswog, S. & Thielemann, F.-K. R-Process in NeutronStar Mergers. Astrophys. J. Lett. 525, L121–L124 (1999).
6. Ji, A. P., Frebel, A., Simon, J. D. & Chiti, A. Complete Element Abundances of Nine Stars in the r-process Galaxy Reticulum II. Astrophys. J.
37830, 93 (2016).
7. Metzger, B. D. et al. Electromagnetic counterparts of compact object
mergers powered by the radioactive decay of r-process nuclei. Mon. Not.
R. Astron. Soc. 406, 2650–2662 (2010).
8. Barnes, J. & Kasen, D. Effect of a High Opacity on the Light Curves ofRadioactively Powered Transients from Compact Object Mergers. Astrophys. J. 775, 18 (2013).
9. Tanvir, N. R. et al. A ‘kilonova’ associated with the short-duration -ray36
burst GRB 130603B. Nature 500, 547–549 (2013).
10. Abbott, B. P., Abbott, R. & et al. GW170817:
13Observation of Gravitational
Waves from a Binary Neutron Star Inspiral. Physical Review Letters 119,161101 (2017).
11. Pian, E. et al. Spectroscopic identification of r-process nucleosynthesis
in a double neutron-star merger. Nature 551, 67–70 (2017).
12. Smartt, S. J. et al. A kilonova as the electromagnetic counterpart to a
gravitational-wave source. Nature 551, 75–79 (2017).
13. Baade, W. & Zwicky, F. Cosmic Rays from Super-novae. Proceedings of
the National Academy of Science 20, 259–263 (1934).
14. Tanaka, M. & Hotokezaka, K. Radiative Transfer Simulations of NeutronStar Merger Ejecta. Astrophys. J. 775, 113 (2013).
15. Kasen, D., Metzger, B., Barnes, J., Quataert, E. & Ramirez-Ruiz, E.
Origin of the heavy elements in binary neutron-star mergers from agravitational-wave event. Nature 551, 80–84 (2017).
16. Sneden, C., Bean, J., Ivans, I., Lucatello, S. & Sobeck, J. MOOG: LTEline analysis and spectrum synthesis. Astrophysics Source Code Library(2012).
17. Kerzendorf, W. E. & Sim, S. A. A spectral synthesis code for rapid modelling of supernovae. Mon. Not. R. Astron. Soc. 440, 387–404 (2014).
18. Lodders, K., Palme, H. & Gail, H.-P.
Abundances of the Elements in the Solar System. Landolt Börnstein (2009). 2011 update
arxiv:0901.1149v2.
19. Bisterzo, S., Travaglio, C., Gallino, R., Wiescher, M. & Käppeler, F. Galactic Chemical Evolution and Solar s-process Abundances: Dependence
on the 13 C-pocket Structure. Astrophys. J. 787, 10 (2014).
20. Honda, S., Aoki, W., Ishimaru, Y. & Wanajo, S. Neutron-Capture Elements in the Very Metal-poor Star HD 88609: Another Star with Excesses of Light Neutron-Capture Elements. Astrophys. J. 666, 1189–

KH et al 21

40

10
Residual F [10 17 erg s 1 cm 2 Å ]Watson et al 19

decades later30 . However, no spectroscopic confirmation of the com1
position of neutron stars has ever been made. The identification here ofan element that could only have been synthesised so quickly under an
extreme neutron flux, provides the first direct spectroscopic evidence
that neutron stars comprise neutron-rich matter.

10

1

F [10 17 erg s 1 cm 2 Å ] + offset

Blackbody + Sr ii
Blackbody

N

10

10

10

10

total
E1
M1

1014

1015 1013[Hz]

ランタノイドは特殊な構造を持つため 許容遷移 ~ eV 程度まで存在

Figure 9. Normalized spectra for Nd II, Nd III, and Nd IV. Here w-> 可視-近赤外(~1μm)付近まで弱い許容遷移による吸収線がたくさん。
electron fraction of j = 1. These values roughly correspond to tho
depict the total spectrum, the contribution of E1 transitions, and thefrom Sris also 1,050
nm. This adds to our confidence in the line idenλ >~1μmの禁制線からなる構造が１週間後くらいには出てくるはず(blue) and M1 (red) lines. The Doppler broadening of each line at atification based on the simple thermal r-process absorption model.
We further confirm our results using TARDIS, extending the code’s⇡ (E0 /2) a8 = 0.1a8 .
atomic database to include elements up to U with the latest Ku92

rucz linelists24 with its 2.31 million lines. Our TARDIS models produce results very similar to our static-code models, reproducing thespectra well (Extended Data Fig. 6). In particular, the P Cygni emission/absorption structure is well-reproduced as expected, confirming
our LTE and MOOG modelling, and showing Sr dominating the fea-

可視から中間赤外(~20μm)まで広くカバーする分光・測光データがあると素晴らしい。
(例：JWSTだと100Mpcくらいまで構造を分解可能)

GW170817 残光・超光速度運動
VLBI
Day 240H0 from GW + VLBI

Day 75

KH+, 19
Mooley,..KH, 18

GRB ジェットの運動を始めて分解

Figure 1: Proper motion of •the radio counterpart of GW170817. The centroid offset posi-tions (shown by 1 errorbars) and 3 -12 contours of the radio source detected 75 d (black)•

ジェットのローレンツ因子 > 4

and 230 d (red) post-merger with Very Long Baseline Interferometry (VLBI) at 4.5 GHz. The•

ジェットに対する見込み角~1 20度1

two VLBI epochs have image RMS noise of 5.0 µJy beam•and 5.6 µJy beam(natural-

この観測、実は、スペースなら可視・赤外でも可能

weighting) respectively, and the peak flux densities of GW170817 are 58 µJy beam 1 and 48 µJy

キロノバ Golden observation
t=0 重力波検出(t~1sec GRB)
~ 1hr UVでキロノバ 発見
ジェットとエジェクタの相互作用がわかる~ 数hr - 数ヶ月 可視・赤外測光
キロノバ のエネルギー源を特定(β崩壊、核分裂、中心エンジン?)~ 数日~ 数ヶ月 可視・赤外分光
可視近赤外の強い吸収線・輝線から元素特定
放射性崩壊で崩壊で消えていく成分も見つかる~ 数日 ~ 数年 電波, 可視, X線で残光ジェットの構造や粒子加速に関する知見~ 数ヶ月 電波・可視でジェット超光速度運動を分解
ジェットのローレンツ因子を測り、連星合体に対する見込み角を決定~ 数年 電波でキロノバ 残骸を分解
キロノバ エジェクタの構造を得る※これは30年代には完了してるかもしれない

第三世代と重力波天文学
第３世代の地上干渉計（2030年代）-

中性子星合体は毎日10個、典型的な距離が1Gpcを優に超えてくる。

-

初代星由来のBBHもあれば見つかる（z~10）

1. 近傍イベント. D=O(100Mpc)-

できるだけ早く見つけて詳細な観測（X or UV -> opt/IR -> X-radio）

2. 標準サイレン宇宙論（z~1）-

GRBを特定する（5％が付随すれば、年間〜100回）-

可視・赤外の測光・分光追観測でキロノバを確認して、母銀河の赤方偏移-

宇宙の膨張率をz~1くらいまで正確に測る。（電波だともっと遠くまで行くか、Dobie KH＋21）

3. 重力波のstrong lensing(Oguri 18, 19)-

年間O(100)-

中性子星合体の電磁波対応天体と組み合わせれば宇宙論、基礎物理に対する強力なProbeになる。strong lensと判明してからの観測でよければ、電波，SKA,
ng-VLA, DSA2000

GW170817を遠くに置くと

2.5 Outlook for Extreme Matter and Extreme Environments

11

FACILITIES FOR O BSERVING EM C OUNTERPARTS TO GW S
Table 2.2: Present (P) and future (F) EM facilities that are able to observe faint/distant counterparts to GWs.
Detection Limit (DL, 1 hr exposure time) for UV, optical, and near-IR facilities are expressed in AB magnitudes,
for X-rays in 10 16 erg s 1 cm2 , and for radio in µJy. Distance reach (D in Mpc) of facilities for GW170817-likeevents are also shown.
Gamma-rays

X-raysUV
OpticalImagingIR
Imaging

Facility
Fermi PAMEGO F
Swift P
Chandra P
ATHENA F
Lynx FSTROBE-X F
HST (im) P
HST (spec) P
Subaru P
LSST FWFIRST F
Euclid F

DL
S/N 5
S/N 5
S/N 5
30
3
6
S/N 5
26
23
27
27
27.5
25.2

D
80
130
⇠80
150
480
450
120
2000
400
3200
3200
4800
1700

OpticalSpec.
Infrared
Spec.

Radio

Facility
Keck/VLT
Gemini Obs.
GMT F
TMT F
E-ELT F
Keck/VLT
GMT F
TMT F
E-ELT FVLA (S) P
ATCA (CX) P
ngVLA (S) F
SKA-mid (L) F

DL
23
23
25
25.5
26
21.5
23.5
24
24.5
5
42
1.5
0.72

D
500
500
1265
1592
2005
481
762
960
1208
91
51
353
634

The next global generation gravitational wave observatory science bookproduce prompt EM signals or even precursors? What is the distribution of the time delays between the EM
単純には、HSC, LSST, Romanでキロノバ探査が有力
and GW signal arrival times? What are the characteristics of a jet from a NS-BH merger? A census of NS
binary mergers, and full GW and EM coverage of the signals, joint multimessenger parameter inference2020-30年代の3つの軸
1. Time-domain: 突発天体から新たな天体の同定し、新しいサイエンスを展開する。多波長が極めて重要。
2. Multi-Messenger Time-domain: 重力波天体、ときどき
電磁波対応天体が見つかる。30年代後半にはニュートリ
ノ天体も出てくる。
3. Survey & Characterization: 天文サーベイデータ（Gaiaなど）やコンパクト天体を発見し、質量などを詳細に決定する。（系外惑星の方法と類似）•

現在、重力波BHの数 ~ 100 これから定常的に増え続ける(104 個第３世代)。

•

銀河系の電磁波から見つかっているBHが15ほど。

•

銀河系に存在するはずの1億個ほどのBHはどこに眠っているのか？

眠っているBHの探査の展望•

eROSITA: X線連星, ~300(Doroshenko+ 14)、孤立BH (Kimura,
Kashiyama, KH 21)•

TESS: BH＋主系列, a few x 100 (Masuda & KH 19)•

Gaia: Astrometric BH連星, 100 - 105 (e.g., Mashian & Loeb 17,
Yamaguchi+18, Yallnewich..KH,18)•

Vera Rubin: マイクロレンズ BHs, ~105 (Natasha & Takada 20)
電磁波BHの数が再び重力波BHの数を上回る可能性もある

22

眠っているBHの探査の現状

T. Jayasinghe et al.

Jayasinghe+21

ThompsonUniconeGiraﬀeFigure 16. BH masses as a function of orbital period for X-ray binaries (black), non-interacting binaries in globular clusters (blue; Giesers et al. 2018, 2019) andマイクロレンズ天体も！MOA-11-191/OGLE-11-0462
BH
orforNS(Sahu+22,
Lam+22)
non-interacting
binaries in the field (red; Thompson et al. 2019; Jayasinghe et al. 2021b). The BH masses andperiods
the X-raybinaries are from
Tetarenko
et al. (2016). From the limited sample of non-interacting compact objects in the field, we see hints that the typical non-interacting BH masses are lower than
expected from the mass distribution of the X-ray binaries.

今は少ししかないが、10年~20年後には、HR図のようにTable 9. Comparison of the possible scenarios involving stellar companions (*), white dwarfs (WD), neutron stars (NS) and black holes (BH) that can explain
the nature of the companion. We assumed "comp ' 3.0 " from the PHOEBE model with 'giant = 29 ' (§3.3, Table 6). A ‘3’ indicates that the scenario
is possible, a ‘?’ indicates that while the scenario is technically possible, it is very unlikely and a ‘7’ indicates that the scenario is ruled out. The simplest

たくさんのブラックホールで埋まる。

20年後、コンパクト天体どうなるか？
超新星爆発と恒星進化-

ショックブレークアウトなどから、超新星の多様性と恒星進化が結びつく。

-

GRBジェット駆動条件、爆発せず重力崩壊で消える条件が判明。

第３世代の地上干渉計（観測的宇宙論と連携）-

中性子星合体は毎日10-100個。

-

標準サイレン宇宙論が赤方偏移2まで伸ばせるか。(GRB & 電波)-

重力レンズ重力波が出てくる。

-

できる多く、遠くの対応天体を特定できる装置・戦略が重要になる。

サーベイ天文学（系外惑星探査と連携）-

ブラックホールが1万個観測され、BBHマイクロレンズや自己レンズするBH連星などか連星進化や重力理論のテストができる。

その他-

LISA, TianQin, DECIGOから新たな重力波天体、IceCube-Gen2からニュートリノ天体が見つかる。

-

フォローアップ観測には膨大な突発天体から適切な選択が必要。