A&A 659, A84 (2022)
https:
//
doi.org
/
10.1051
/
0004-6361
/
202141452
c
©
ESO 2022
Astronomy
&
Astrophysics
Search for intermediate-mass black hole binaries in the third
observing run of Advanced LIGO and Advanced Virgo
R. Abbott
1
, T. D. Abbott
2
, F. Acernese
3 ,4
, K. Ackley
5
, C. Adams
6
, N. Adhikari
7
, R. X. Adhikari
1
, V. B. Adya
8
, C. A
ff
eldt
9 ,10
,
D. Agarwal
11
, M. Agathos
12 ,13
, K. Agatsuma
14
, N. Aggarwal
15
, O. D. Aguiar
16
, L. Aiello
17
, A. Ain
18
, P. Ajith
19
, T. Akutsu
20 ,21
,
S. Albanesi
22
, A. Allocca
23 ,4
, P. A. Altin
8
, A. Amato
24
, C. Anand
5
, S. Anand
1
, A. Ananyeva
1
, S. B. Anderson
1
, W. G. Anderson
7
,
M. Ando
25 ,26
, T. Andrade
27
, N. Andres
28
, T. Andri
́
c
29
, S. V. Angelova
29
, S. Ansoldi
30 ,31
, J. M. Antelis
32
, S. Antier
33
, S. Appert
1
,
K. Arai
1
, K. Arai
34
, Y. Arai
34
, S. Araki
35
, A. Araya
36
, M. C. Araya
1
, J. S. Areeda
37
, M. Arène
33
, N. Aritomi
25
, N. Arnaud
38 ,39
,
S. M. Aronson
2
, K. G. Arun
40
, H. Asada
41
, Y. Asali
42
, G. Ashton
5
, Y. Aso
43 ,44
, M. Assiduo
45 ,46
, S. M. Aston
6
, P. Astone
47
,
F. Aubin
28
, C. Austin
2
, S. Babak
33
, F. Badaracco
48
, M. K. M. Bader
49
, C. Badger
50
, S. Bae
51
, Y. Bae
52
, A. M. Baer
53
, S. Bagnasco
22
,
Y. Bai
1
, L. Baiotti
54
, J. Baird
33
, R. Bajpai
55
, M. Ball
56
, G. Ballardin
39
, S. W. Ballmer
57
, A. Balsamo
53
, G. Baltus
58
, S. Banagiri
59
,
D. Bankar
11
, J. C. Barayoga
1
, C. Barbieri
60 ,61 ,62
, B. C. Barish
1
, D. Barker
63
, P. Barneo
27
, F. Barone
64 ,4
, B. Barr
65
, L. Barsotti
66
,
M. Barsuglia
33
, D. Barta
67
, J. Bartlett
63
, M. A. Barton
65 ,20
, I. Bartos
68
, R. Bassiri
69
, A. Basti
70 ,18
, M. Bawaj
71 ,72
, J. C. Bayley
65
,
A. C. Baylor
7
, M. Bazzan
73 ,74
, B. Bécsy
75
, V. M. Bedakihale
76
, M. Bejger
77
, I. Belahcene
38
, V. Benedetto
78
, D. Beniwal
79
,
T. F. Bennett
80
, J. D. Bentley
14
, M. BenYaala
29
, F. Bergamin
9 ,10
, B. K. Berger
69
, S. Bernuzzi
13
, C. P. L. Berry
15 ,65
, D. Bersanetti
81
,
A. Bertolini
49
, J. Betzwieser
6
, D. Beveridge
82
, R. Bhandare
83
, U. Bhardwaj
84 ,49
, D. Bhattacharjee
85
, S. Bhaumik
68
, I. A. Bilenko
86
,
G. Billingsley
1
, S. Bini
87 ,88
, R. Birney
89
, O. Birnholtz
90
, S. Biscans
1,66
, M. Bischi
45 ,46
, S. Biscoveanu
66
, A. Bisht
9 ,10
, B. Biswas
11
,
M. Bitossi
39 ,18
, M.-A. Bizouard
91
, J. K. Blackburn
1
, C. D. Blair
82 ,6
, D. G. Blair
82
, R. M. Blair
63
, F. Bobba
92 ,93
, N. Bode
9 ,10
,
M. Boer
91
, G. Bogaert
91
, M. Boldrini
94 ,47
, L. D. Bonavena
73
, F. Bondu
95
, E. Bonilla
69
, R. Bonnand
28
, P. Booker
9 ,10
, B. A. Boom
49
,
R. Bork
1
, V. Boschi
18
, N. Bose
96
, S. Bose
11
, V. Bossilkov
82
, V. Boudart
58
, Y. Bou
ff
anais
73 ,74
, A. Bozzi
39
, C. Bradaschia
18
,
P. R. Brady
7
, A. Bramley
6
, A. Branch
6
, M. Branchesi
29 ,97
, J. E. Brau
56
, M. Breschi
13
, T. Briant
98
, J. H. Briggs
65
, A. Brillet
91
,
M. Brinkmann
9 ,10
, P. Brockill
7
, A. F. Brooks
1
, J. Brooks
39
, D. D. Brown
79
, S. Brunett
1
, G. Bruno
48
, R. Bruntz
53
, J. Bryant
14
,
T. Bulik
99
, H. J. Bulten
49
, A. Buonanno
100 ,101
, R. Buscicchio
14
, D. Buskulic
28
, C. Buy
102
, R. L. Byer
69
, L. Cadonati
103
, G. Cagnoli
24
,
C. Cahillane
63
, J. Calderón Bustillo
104 ,105
, J. D. Callaghan
65
, T. A. Callister
106 ,107
, E. Calloni
23 ,4
, J. Cameron
82
, J. B. Camp
108
,
M. Canepa
109 ,81
, S. Canevarolo
110
, M. Cannavacciuolo
92
, K. C. Cannon
111
, H. Cao
79
, Z. Cao
112
, E. Capocasa
20
, E. Capote
57
,
G. Carapella
92 ,93
, F. Carbognani
39
, J. B. Carlin
113
, M. F. Carney
15
, M. Carpinelli
114 ,115 ,39
, G. Carrillo
56
, G. Carullo
70 ,18
, T. L. Carver
17
,
J. Casanueva Diaz
39
, C. Casentini
116 ,117
, G. Castaldi
118
, S. Caudill
49 ,110
, M. Cavaglià
85
, F. Cavalier
38
, R. Cavalieri
39
, M. Ceasar
119
,
G. Cella
18
, P. Cerdá-Durán
120
, E. Cesarini
117
, W. Chaibi
91
, K. Chakravarti
11
, S.
Chalathadka Subrahmanya
121
, E. Champion
122
,
C.-H. Chan
123
, C. Chan
111
, C. L. Chan
105
, K. Chan
105
, M. Chan
124
, K. Chandra
96
, P. Chanial
39
, S. Chao
123
, P. Charlton
125
,
E. A. Chase
15
, E. Chassande-Mottin
33
, C. Chatterjee
82
, D. Chatterjee
11
, D. Chatterjee
7
, M. Chaturvedi
83
, S. Chaty
33
, K. Chatziioannou
1
,
C. Chen
126 ,127
, H. Y. Chen
66
, J. Chen
123
, K. Chen
128
, X. Chen
82
, Y.-B. Chen
129
, Y.-R. Chen
130
, Z. Chen
17
, H. Cheng
68
, C. K. Cheong
105
,
H. Y. Cheung
105
, H. Y. Chia
68
, F. Chiadini
131 ,93
, C-Y. Chiang
132
, G. Chiarini
74
, R. Chierici
133
, A. Chincarini
81
, M. L. Chiofalo
70 ,18
,
A. Chiummo
39
, G. Cho
134
, H. S. Cho
135
, R. K. Choudhary
82
, S. Choudhary
11
, N. Christensen
91
, H. Chu
128
, Q. Chu
82
,
Y-K. Chu
132
, S. Chua
8
, K. W. Chung
50
, G. Ciani
73 ,74
, P. Ciecielag
77
, M. Cie
́
slar
77
, M. Cifaldi
116 ,117
, A. A. Ciobanu
79
, R. Ciolfi
136 ,74
,
F. Cipriano
91
, A. Cirone
109 ,81
, F. Clara
63
, E. N. Clark
137
, J. A. Clark
1,103
, L. Clarke
138
, P. Clearwater
139
, S. Clesse
140
, F. Cleva
91
,
E. Coccia
29 ,97
, E. Codazzo
29
, P.-F. Cohadon
98
, D. E. Cohen
38
, L. Cohen
2
, M. Colleoni
141
, C. G. Collette
142
, A. Colombo
60
,
M. Colpi
60 ,61
, C. M. Compton
63
, M. Constancio Jr.
16
, L. Conti
74
, S. J. Cooper
14
, P. Corban
6
, T. R. Corbitt
2
, I. Cordero-Carrión
143
,
S. Corezzi
72 ,71
, K. R. Corley
42
, N. Cornish
75
, D. Corre
38
, A. Corsi
144
, S. Cortese
39
, C. A. Costa
16
, R. Cotesta
101
, M. W. Coughlin
59
,
J.-P. Coulon
91
, S. T. Countryman
42
, B. Cousins
145
, P. Couvares
1
, D. M. Coward
82
, M. J. Cowart
6
, D. C. Coyne
1
, R. Coyne
146
,
J. D. E. Creighton
7
, T. D. Creighton
147
, A. W. Criswell
59
, M. Croquette
98
, S. G. Crowder
148
, J. R. Cudell
58
, T. J. Cullen
2
,
A. Cumming
65
, R. Cummings
65
, L. Cunningham
65
, E. Cuoco
39 ,149 ,18
, M. Curyło
99
, P. Dabadie
24
, T. Dal Canton
38
, S. Dall’Osso
29
,
G. Dálya
150
, A. Dana
69
, L. M. Daneshgaran Bajastani
80
, B. D’Angelo
109 ,81
, S. Danilishin
151 ,49
, S. D’Antonio
117
, K. Danzmann
9 ,10
,
C. Darsow-Fromm
121
, A. Dasgupta
76
, L. E. H. Datrier
65
, S. Datta
11
, V. Dattilo
39
, I. Dave
83
, M. Davier
38
, G. S. Davies
152
, D. Davis
1
,
M. C. Davis
119
, E. J. Daw
153
, R. Dean
119
, D. DeBra
69
, M. Deenadayalan
11
, J. Degallaix
154
, M. De Laurentis
23 ,4
, S. Deléglise
98
,
V. Del Favero
122
, F. De Lillo
48
, N. De Lillo
65
, W. Del Pozzo
70 ,18
,?
, L. M. De Marchi
15
, F. De Matteis
116 ,117
, V. D’Emilio
17
,
N. Demos
66
, T. Dent
104
, A. Depasse
48
, R. De Pietri
155 ,156
, R. De Rosa
23 ,4
, C. De Rossi
39
, R. De Salvo
118
, R. De Simone
131
,
S. Dhurandhar
11
, M. C. Díaz
147
, M. Diaz-Ortiz Jr.
68
, N. A. Didio
57
, T. Dietrich
101 ,49
, L. Di Fiore
4
, C. Di Fronzo
14
, C. Di Giorgio
92 ,93
,
F. Di Giovanni
120
, M. Di Giovanni
29
, T. Di Girolamo
23 ,4
, A. Di Lieto
70 ,18
, B. Ding
142
, S. Di Pace
94 ,47
, I. Di Palma
94 ,47
, F. Di Renzo
70 ,18
,
A. K. Divakarla
68
, A. Dmitriev
14
, Z. Doctor
56
, L. D’Onofrio
23 ,4
, F. Donovan
66
, K. L. Dooley
17
, S. Doravari
11
, I. Dorrington
17
,
M. Drago
94 ,47
, J. C. Driggers
63
, Y. Drori
1
, J.-G. Ducoin
38
, P. Dupej
65
, O. Durante
92 ,93
, D. D’Urso
114 ,115
, P.-A. Duverne
38
, S. E. Dwyer
63
,
C. Eassa
63
, P. J. Easter
5
, M. Ebersold
157
, T. Eckhardt
121
, G. Eddolls
65
, B. Edelman
56
, T. B. Edo
1
, O. Edy
152
, A. E
ffl
er
6
, S. Eguchi
124
,
J. Eichholz
8
, S. S. Eikenberry
68
, M. Eisenmann
28
, R. A. Eisenstein
66
, A. Ejlli
17
, E. Engelby
37
, Y. Enomoto
25
, L. Errico
23 ,4
, R. Essick
158
,
H. Estellés
141
, D. Estevez
159
, Z. Etienne
160
, T. Etzel
1
, M. Evans
66
, T. M. Evans
6
, B. E. Ewing
145
, V. Fafone
116 ,117 ,29
, H. Fair
57
,
S. Fairhurst
17
, A. M. Farah
158
, S. Farinon
81
, B. Farr
56
, W. M. Farr
106 ,107
, N. W. Farrow
5
, E. J. Fauchon-Jones
17
, G. Favaro
73
,
M. Favata
161
, M. Fays
58
, M. Fazio
162
, J. Feicht
1
, M. M. Fejer
69
, E. Fenyvesi
67 ,163
, D. L. Ferguson
164
, A. Fernandez-Galiana
66
,
I. Ferrante
70 ,18
, T. A. Ferreira
16
, F. Fidecaro
70 ,18
, P. Figura
99
, I. Fiori
39
, M. Fishbach
15
, R. P. Fisher
53
, R. Fittipaldi
165 ,93
,
?
Corresponding author: W. Del Pozzo, e-mail:
walter.delpozzo@unipi.it
Article published by EDP Sciences
A84, page 1 of 25
A&A 659, A84 (2022)
V. Fiumara
166 ,93
,
R. Flaminio
28 ,167
,
E. Floden
59
,
H. Fong
111
,
J.
A. Font
120 ,168
,
B. Fornal
169
,
P.
W.
F. Forsyth
8
,
A. Franke
121
,
S. Frasca
94 ,47
,
F. Frasconi
18
,
C. Frederick
170
,
J.
P. Freed
32
,
Z. Frei
150
,
A. Freise
171
,
R. Frey
56
,
P. Fritschel
66
,
V.
V. Frolov
6
,
G. G. Fronzé
22
, Y. Fujii
172
, Y. Fujikawa
173
, M. Fukunaga
34
, M. Fukushima
21
, P. Fulda
68
, M. Fy
ff
e
6
, H. A. Gabbard
65
, B. U. Gadre
101
,
J. R. Gair
101
, J. Gais
105
, S. Galaudage
5
, R. Gamba
13
, D. Ganapathy
66
, A. Ganguly
19
, D. Gao
174
, S. G. Gaonkar
11
, B. Garaventa
81 ,109
,
C. García-Núñez
89
, C. García-Quirós
141
, F. Garufi
23 ,4
, B. Gateley
63
, S. Gaudio
32
, V. Gayathri
68
, G.-G. Ge
174
, G. Gemme
81
, A. Gennai
18
,
J. George
83
,
O. Gerberding
121
,
L. Gergely
175
,
P. Gewecke
121
,
S. Ghonge
103
,
A. Ghosh
101
,
A. Ghosh
176
,
S. Ghosh
7 ,161
,
S. Ghosh
17
,
B. Giacomazzo
60 ,61 ,62
, L. Giacoppo
94 ,47
, J. A. Giaime
2 ,6
, K. D. Giardina
6
, D. R. Gibson
89
, C. Gier
29
, M. Giesler
177
, P. Giri
18 ,70
, F. Gissi
78
,
J. Glanzer
2
, A. E. Gleckl
37
, P. Godwin
145
, E. Goetz
178
, R. Goetz
68
, N. Gohlke
9 ,10
, B. Goncharov
5 ,29
, G. González
2
, A. Gopakumar
179
,
M. Gosselin
39
, R. Gouaty
28
, D. W. Gould
8
, B. Grace
8
, A. Grado
180 ,4
, M. Granata
154
, V. Granata
92
, A. Grant
65
, S. Gras
66
, P. Grassia
1
, C. Gray
63
,
R. Gray
65
, G. Greco
71
, A. C. Green
68
, R. Green
17
, A. M. Gretarsson
32
, E. M. Gretarsson
32
, D. Gri
ffi
th
1
, W. Gri
ffi
ths
17
, H. L. Griggs
103
,
G. Grignani
72 ,71
, A. Grimaldi
87 ,88
, S. J. Grimm
29 ,97
, H. Grote
17
, S. Grunewald
101
, P. Gruning
38
, D. Guerra
120
, G. M. Guidi
45 ,46
, A. R. Guimaraes
2
,
G. Guixé
27
, H. K. Gulati
76
, H.-K. Guo
167
, Y. Guo
49
, A. Gupta
1
, A. Gupta
181
, P. Gupta
49 ,110
, E. K. Gustafson
1
, R. Gustafson
182
, F. Guzman
183
,
S. Ha
184
, L. Haegel
33
, A. Hagiwara
34 ,185
, S. Haino
132
, O. Halim
31 ,186
, E. D. Hall
66
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157
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65
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187
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M. Haney
157
, J. Hanks
63
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145
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17
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110 ,49
, H. Hansen
63
, T. J. Hansen
32
, J. Hanson
6
, T. Harder
91
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T. Hardwick
2
, K. Haris
49 ,110
, J. Harms
29 ,97
, G. M. Harry
188
, I. W. Harry
152
, D. Hartwig
121
, K. Hasegawa
34
, B. Haskell
77
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6
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C.-J. Haster
66
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189
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65
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190
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124
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65
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122
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98
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9 ,10
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M. C. Heintze
6
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9 ,10
, J. Heinzel
191
, H. Heitmann
91
, F. Hellman
192
, P. Hello
38
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56
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39
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65
,
I. S. Heng
65
, E. Hennes
49
, J. Hennig
193
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193
, A. G. Hernandez
80
, F. Hernandez Vivanco
5
, M. Heurs
9 ,10
, S. Hild
151 ,49
, P. Hill
29
,
Y. Himemoto
194
, A. S. Hines
183
, Y. Hiranuma
195
, N. Hirata
20
, E. Hirose
34
, S. Hochheim
9 ,10
, D. Hofman
154
, J. N. Hohmann
121
, D. G. Holcomb
119
,
N. A. Holland
8
, I. J. Hollows
153
, Z. J. Holmes
79
, K. Holt
6
, D. E. Holz
158
, Z. Hong
196
, P. Hopkins
17
, J. Hough
65
, S. Hourihane
129
, E. J. Howell
82
,
C. G. Hoy
17
, D. Hoyland
14
, A. Hreibi
9 ,10
, B-H. Hsieh
34
, Y. Hsu
123
, G-Z. Huang
196
, H-Y. Huang
132
, P. Huang
174
, Y-C. Huang
130
, Y.-J. Huang
132
,
Y. Huang
66
, M. T. Hübner
5
, A. D. Huddart
138
, B. Hughey
32
, D. C. Y. Hui
197
, V. Hui
28
, S. Husa
141
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65
, R. Huxford
145
,
T. Huynh-Dinh
6
, S. Ide
198
, B. Idzkowski
99
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116 ,117
, B. Ikenoue
21
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196
, K. Inayoshi
199
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79
, Y. Inoue
128
, K. Ioka
200
, M. Isi
66
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K. Isleif
121
, K. Ito
201
, Y. Itoh
202 ,203
, B. R. Iyer
19
, K. Izumi
204
, V. Jaberian Hamedan
82
, T. Jacqmin
98
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205
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11
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17
,
A. Z. Jan
122
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206
, J. Janquart
110 ,49
, K. Janssens
207 ,91
, N. N. Janthalur
205
, P. Jaranowski
208
, D. Jariwala
68
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141
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50
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K. Jenner
79
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209
, M. Jeunon
59
, W. Jia
66
, H.-B. Jin
210 ,211
, G. R. Johns
53
, A. W. Jones
82
, D. I. Jones
212
, J. D. Jones
63
, P. Jones
14
, R. Jones
65
,
R. J. G. Jonker
49
, L. Ju
82
, P. Jung
52
, k. Jung
184
, J. Junker
9 ,10
, V. Juste
159
, K. Kaihotsu
201
, T. Kajita
213
, M. Kakizaki
214
, C. V. Kalaghatgi
17 ,110
,
V. Kalogera
15
, B. Kamai
1
, M. Kamiizumi
190
, N. Kanda
202 ,203
, S. Kandhasamy
11
, G. Kang
215
, J. B. Kanner
1
, Y. Kao
123
, S. J. Kapadia
19
,
D. P. Kapasi
8
, S. Karat
1
, C. Karathanasis
216
, S. Karki
85
, R. Kashyap
145
, M. Kasprzack
1
, W. Kastaun
9 ,10
, S. Katsanevas
39
, E. Katsavounidis
66
,
W. Katzman
6
, T. Kaur
82
, K. Kawabe
63
, K. Kawaguchi
34
, N. Kawai
217
, T. Kawasaki
25
, F. Kéfélian
91
, D. Keitel
141
, J. S. Key
218
, S. Khadka
69
,
F. Y. Khalili
86
, S. Khan
17
, E. A. Khazanov
219
, N. Khetan
29 ,97
, M. Khursheed
83
, N. Kijbunchoo
8
, C. Kim
220
, J. C. Kim
221
, J. Kim
222
, K. Kim
223
,
W. S. Kim
224
, Y.-M. Kim
225
, C. Kimball
15
, N. Kimura
185
, M. Kinley-Hanlon
65
, R. Kirchho
ff
9 ,10
, J. S. Kissel
63
, N. Kita
25
, H. Kitazawa
201
,
L. Kleybolte
121
, S. Klimenko
68
, A. M. Knee
178
, T. D. Knowles
160
, E. Knyazev
66
, P. Koch
9 ,10
, G. Koekoek
49 ,151
, Y. Kojima
226
, K. Kokeyama
227
,
S. Koley
29
, P. Kolitsidou
17
, M. Kolstein
216
, K. Komori
66 ,25
, V. Kondrashov
1
, A. K. H. Kong
228
, A. Kontos
229
, N. Koper
9 ,10
, M. Korobko
121
,
K. Kotake
124
, M. Kovalam
82
, D. B. Kozak
1
, C. Kozakai
43
, R. Kozu
190
, V. Kringel
9 ,10
, N. V. Krishnendu
9 ,10
, A. Królak
230 ,231
, G. Kuehn
9 ,10
,
F. Kuei
123
, P. Kuijer
49
, A. Kumar
205
, P. Kumar
177
, R. Kumar
63
, R. Kumar
76
, J. Kume
26
, K. Kuns
66
, C. Kuo
128
, H-S. Kuo
196
, Y. Kuromiya
201
,
S. Kuroyanagi
232 ,233
, K. Kusayanagi
217
, S. Kuwahara
111
, K. Kwak
184
, P. Lagabbe
28
, D. Laghi
70 ,18
, E. Lalande
234
, T. L. Lam
105
, A. Lamberts
91 ,235
,
M. Landry
63
, B. B. Lane
66
, R. N. Lang
66
, J. Lange
164
, B. Lantz
69
, I. La Rosa
28
, A. Lartaux-Vollard
38
, P. D. Lasky
5
, M. Laxen
6
, A. Lazzarini
1
,
C. Lazzaro
73 ,74
, P. Leaci
94 ,47
, S. Leavey
9 ,10
, Y. K. Lecoeuche
178
, H. K. Lee
236
, H. M. Lee
134
, H. W. Lee
221
, J. Lee
134
, K. Lee
237
, R. Lee
130
,
J. Lehmann
9 ,10
, A. Lemaître
238
, M. Leonardi
20
, N. Leroy
38
, N. Letendre
28
, C. Levesque
234
, Y. Levin
5
, J. N. Leviton
182
, K. Leyde
33
, A. K. Y. Li
1
,
B. Li
123
, J. Li
15
, K. L. Li
239
, T. G. F. Li
105
, X. Li
129
, C-Y. Lin
240
, F-K. Lin
132
, F-L. Lin
196
, H. L. Lin
128
, L. C.-C. Lin
184
, F. Linde
241 ,49
,
S. D. Linker
80
, J. N. Linley
65
, T. B. Littenberg
242
, G. C. Liu
126
, J. Liu
9 ,10
, K. Liu
123
, X. Liu
7
, F. Llamas
147
, M. Llorens-Monteagudo
120
,
R. K. L. Lo
1
, A. Lockwood
243
, L. T. London
66
, A. Longo
244 ,245
, D. Lopez
157
, M. Lopez Portilla
110
, M. Lorenzini
116 ,117
, V. Loriette
246
,
M. Lormand
6
, G. Losurdo
18
, T. P. Lott
103
, J. D. Lough
9 ,10
, C. O. Lousto
122
, G. Lovelace
37
, J. F. Lucaccioni
170
, H. Lück
9 ,10
, D. Lumaca
116 ,117
,
A. P. Lundgren
152
, L.-W. Luo
132
, J. E. Lynam
53
, R. Macas
152
, M. MacInnis
66
, D. M. Macleod
17
, I. A. O. MacMillan
1
, A. Macquet
91
,
I. Magaña Hernandez
7
, C. Magazzù
18
, R. M. Magee
1
, R. Maggiore
14
, M. Magnozzi
81 ,109
, S. Mahesh
160
, E. Majorana
94 ,47
, C. Makarem
1
,
I. Maksimovic
246
, S. Maliakal
1
, A. Malik
83
, N. Man
91
, V. Mandic
59
, V. Mangano
94 ,47
, J. L. Mango
247
, G. L. Mansell
63 ,66
, M. Manske
7
,
M. Mantovani
39
, M. Mapelli
73 ,74
, F. Marchesoni
248 ,71 ,249
, M. Marchio
20
, F. Marion
28
, Z. Mark
129
, S. Márka
42
, Z. Márka
42
, C. Markakis
12
,
A. S. Markosyan
69
, A. Markowitz
1
, E. Maros
1
, A. Marquina
143
, S. Marsat
33
, F. Martelli
45 ,46
, I. W. Martin
65
, R. M. Martin
161
, M. Martinez
216
,
V. A. Martinez
68
, V. Martinez
24
, K. Martinovic
50
, D. V. Martynov
14
, E. J. Marx
66
, H. Masalehdan
121
, K. Mason
66
, E. Massera
153
, A. Masserot
28
,
T. J. Massinger
66
, M. Masso-Reid
65
, S. Mastrogiovanni
33
, A. Matas
101
, M. Mateu-Lucena
141
, F. Matichard
1,66
, M. Matiushechkina
9 ,10
,
N. Mavalvala
66
, J. J. McCann
82
, R. McCarthy
63
, D. E. McClelland
8
, P. K. McClincy
145
, S. McCormick
6
, L. McCuller
66
, G. I. McGhee
65
,
S. C. McGuire
250
, C. McIsaac
152
, J. McIver
178
, T. McRae
8
, S. T. McWilliams
160
, D. Meacher
7
, M. Mehmet
9 ,10
, A. K. Mehta
101
, Q. Meijer
110
,
A. Melatos
113
, D. A. Melchor
37
, G. Mendell
63
, A. Menendez-Vazquez
216
, C. S. Menoni
162
, R. A. Mercer
7
, L. Mereni
154
, K. Merfeld
56
,
E. L. Merilh
6
, J. D. Merritt
56
, M. Merzougui
91
, S. Meshkov
1
,
†
, C. Messenger
65
, C. Messick
164
, P. M. Meyers
113
, F. Meylahn
9 ,10
, A. Mhaske
11
,
A. Miani
87 ,88
, H. Miao
14
, I. Michaloliakos
68
, C. Michel
154
, Y. Michimura
25
, H. Middleton
113
, L. Milano
23
, A. L. Miller
48
, A. Miller
80
,
B. Miller
84 ,49
, M. Millhouse
113
, J. C. Mills
17
, E. Milotti
186 ,31
, O. Minazzoli
91 ,251
, Y. Minenkov
117
, N. Mio
252
, Ll. M. Mir
216
, M. Miravet-Tenés
120
,
C. Mishra
253
, T. Mishra
68
, T. Mistry
153
, S. Mitra
11
, V. P. Mitrofanov
86
, G. Mitselmakher
68
, R. Mittleman
66
, O. Miyakawa
190
, A. Miyamoto
202
,
Y. Miyazaki
25
, K. Miyo
190
, S. Miyoki
190
, Geo
ff
rey Mo
66
, E. Moguel
170
, K. Mogushi
85
, S. R. P. Mohapatra
66
, S. R. Mohite
7
, I. Molina
37
,
M. Molina-Ruiz
192
, M. Mondin
80
, M. Montani
45 ,46
, C. J. Moore
14
, D. Moraru
63
, F. Morawski
77
, A. More
11
, C. Moreno
32
, G. Moreno
63
,
Y. Mori
201
, S. Morisaki
7
, Y. Moriwaki
214
, B. Mours
159
, C. M. Mow-Lowry
14 ,171
, S. Mozzon
152
, F. Muciaccia
94 ,47
, A. Mukherjee
254
,
D. Mukherjee
145
, S. Mukherjee
147
, S. Mukherjee
76
, S. Mukherjee
84
, N. Mukund
9 ,10
, A. Mullavey
6
, J. Munch
79
, E. A. Muñiz
57
, P. G. Murray
65
,
R. Musenich
81 ,109
, S. Muusse
79
, S. L. Nadji
9 ,10
, K. Nagano
204
, S. Nagano
255
, A. Nagar
22 ,256
, K. Nakamura
20
, H. Nakano
257
, M. Nakano
34
,
R. Nakashima
217
, Y. Nakayama
201
, V. Napolano
39
, I. Nardecchia
116 ,117
, T. Narikawa
34
, L. Naticchioni
47
, B. Nayak
80
, R. K. Nayak
258
,
R. Negishi
195
, B. F. Neil
82
, J. Neilson
78 ,93
, G. Nelemans
259
, T. J. N. Nelson
6
, M. Nery
9 ,10
, P. Neubauer
170
, A. Neunzert
218
, K. Y. Ng
66
,
S. W. S. Ng
79
, C. Nguyen
33
, P. Nguyen
56
, T. Nguyen
66
, L. Nguyen Quynh
260
, W.-T. Ni
210 ,174 ,130
, S. A. Nichols
2
, A. Nishizawa
26
,
S. Nissanke
84 ,49
, E. Nitoglia
133
, F. Nocera
39
, M. Norman
17
, C. North
17
, S. Nozaki
189
, L. K. Nuttall
152
, J. Oberling
63
, B. D. O’Brien
68
,
†
Deceased, August 2020.
A84, page 2 of 25
LVK: Search for intermediate-mass black hole binaries in the O3 run
Y. Obuchi
21
, J. O’Dell
138
, E. Oelker
65
, W. Ogaki
34
, G. Oganesyan
29 ,97
, J. J. Oh
224
, K. Oh
197
, S. H. Oh
224
, M. Ohashi
190
, N. Ohishi
43
,
M. Ohkawa
173
, F. Ohme
9 ,10
, H. Ohta
111
, M. A. Okada
16
, Y. Okutani
198
, K. Okutomi
190
, C. Olivetto
39
, K. Oohara
195
, C. Ooi
25
, R. Oram
6
,
B. O’Reilly
6
, R. G. Ormiston
59
, N. D. Ormsby
53
, L. F. Ortega
68
, R. O’Shaughnessy
122
, E. O’Shea
177
, S. Oshino
190
, S. Ossokine
101
, C. Osthelder
1
,
S. Otabe
217
, D. J. Ottaway
79
, H. Overmier
6
, A. E. Pace
145
, G. Pagano
70 ,18
, M. A. Page
82
, G. Pagliaroli
29 ,97
, A. Pai
96
, S. A. Pai
83
, J. R. Palamos
56
,
O. Palashov
219
, C. Palomba
47
, H. Pan
123
, K. Pan
130 ,228
, P. K. Panda
205
, H. Pang
128
, P. T. H. Pang
49 ,110
, C. Pankow
15
, F. Pannarale
94 ,47
,
B. C. Pant
83
, F. H. Panther
82
, F. Paoletti
18
, A. Paoli
39
, A. Paolone
47 ,261
, A. Parisi
126
, H. Park
7
, J. Park
262
, W. Parker
6 ,250
, D. Pascucci
49
,
A. Pasqualetti
39
, R. Passaquieti
70 ,18
, D. Passuello
18
, M. Patel
53
, M. Pathak
79
, B. Patricelli
39 ,18
, A. S. Patron
2
, S. Patrone
94 ,47
, S. Paul
56
,
E. Payne
5
, M. Pedraza
1
, M. Pegoraro
74
, A. Pele
6
, F. E. Peña Arellano
190
, S. Penn
263
, A. Perego
87 ,88
, A. Pereira
24
, T. Pereira
264
, C. J. Perez
63
,
C. Périgois
28
, C. C. Perkins
68
, A. Perreca
87 ,88
, S. Perriès
133
, J. Petermann
121
, D. Petterson
1
, H. P. Pfei
ff
er
101
, K. A. Pham
59
, K. S. Phukon
49 ,241
,
O. J. Piccinni
47
, M. Pichot
91
, M. Piendibene
70 ,18
, F. Piergiovanni
45 ,46
, L. Pierini
94 ,47
, V. Pierro
78 ,93
, G. Pillant
39
, M. Pillas
38
, F. Pilo
18
,
L. Pinard
154
, I. M. Pinto
78 ,93 ,265
, M. Pinto
39
, K. Piotrzkowski
48
, M. Pirello
63
, M. D. Pitkin
266
, E. Placidi
94 ,47
, L. Planas
141
, W. Plastino
244 ,245
,
C. Pluchar
137
, R. Poggiani
70 ,18
, E. Polini
28
, D. Y. T. Pong
105
, S. Ponrathnam
11
, P. Popolizio
39
, E. K. Porter
33
, R. Poulton
39
, J. Powell
139
,
M. Pracchia
28
, T. Pradier
159
, A. K. Prajapati
76
, K. Prasai
69
, R. Prasanna
205
, G. Pratten
14
, M. Principe
78 ,265 ,93
, G. A. Prodi
267 ,88
, L. Prokhorov
14
,
P. Prosposito
116 ,117
, L. Prudenzi
101
, A. Puecher
49 ,110
, M. Punturo
71
, F. Puosi
18 ,70
, P. Puppo
47
, M. Pürrer
101
, H. Qi
17
, V. Quetschke
147
,
R. Quitzow-James
85
, F. J. Raab
63
, G. Raaijmakers
84 ,49
, H. Radkins
63
, N. Radulesco
91
, P. Ra
ff
ai
150
, S. X. Rail
234
, S. Raja
83
, C. Rajan
83
,
K. E. Ramirez
6
, T. D. Ramirez
37
, A. Ramos-Buades
101
, J. Rana
145
, P. Rapagnani
94 ,47
, U. D. Rapol
268
, A. Ray
7
, V. Raymond
17
, N. Raza
178
,
M. Razzano
70 ,18
, J. Read
37
, L. A. Rees
188
, T. Regimbau
28
, L. Rei
81
, S. Reid
29
, S. W. Reid
53
, D. H. Reitze
1,68
, P. Relton
17
, A. Renzini
1
,
P. Rettegno
269 ,22
, M. Rezac
37
, F. Ricci
94 ,47
, D. Richards
138
, J. W. Richardson
1
, L. Richardson
183
, G. Riemenschneider
269 ,22
, K. Riles
182
,
S. Rinaldi
18 ,70
, K. Rink
178
, M. Rizzo
15
, N. A. Robertson
1,65
, R. Robie
1
, F. Robinet
38
, A. Rocchi
117
, S. Rodriguez
37
, L. Rolland
28
, J. G. Rollins
1
,
M. Romanelli
95
, R. Romano
3 ,4
, C. L. Romel
63
, A. Romero-Rodríguez
216
, I. M. Romero-Shaw
5
, J. H. Romie
6
, S. Ronchini
29 ,97
, L. Rosa
4 ,23
,
C. A. Rose
7
, D. Rosi
́
nska
99
, M. P. Ross
243
, S. Rowan
65
, S. J. Rowlinson
14
, S. Roy
110
, S. Roy
11
, S. Roy
270
, D. Rozza
114 ,115
, P. Ruggi
39
,
K. Ryan
63
, S. Sachdev
145
, T. Sadecki
63
, J. Sadiq
104
, N. Sago
271
, S. Saito
21
, Y. Saito
190
, K. Sakai
272
, Y. Sakai
195
, M. Sakellariadou
50
,
Y. Sakuno
124
, O. S. Salafia
62 ,61 ,60
, L. Salconi
39
, M. Saleem
59
, F. Salemi
87 ,88
, A. Samajdar
49 ,110
, E. J. Sanchez
1
, J. H. Sanchez
37
, L. E. Sanchez
1
,
N. Sanchis-Gual
273
, J. R. Sanders
274
, A. Sanuy
27
, T. R. Saravanan
11
, N. Sarin
5
, B. Sassolas
154
, H. Satari
82
, B. S. Sathyaprakash
145 ,17
, S. Sato
275
,
T. Sato
173
, O. Sauter
68
, R. L. Savage
63
, T. Sawada
202
, D. Sawant
96
, H. L. Sawant
11
, S. Sayah
154
, D. Schaetzl
1
, M. Scheel
129
, J. Scheuer
15
,
M. Schiworski
79
, P. Schmidt
14
, S. Schmidt
110
, R. Schnabel
121
, M. Schneewind
9 ,10
, R. M. S. Schofield
56
, A. Schönbeck
121
, B. W. Schulte
9 ,10
,
B. F. Schutz
17 ,9 ,10
, E. Schwartz
17
, J. Scott
65
, S. M. Scott
8
, M. Seglar-Arroyo
28
, T. Sekiguchi
26
, Y. Sekiguchi
276
, D. Sellers
6
, A. S. Sengupta
270
,
D. Sentenac
39
, E. G. Seo
105
, V. Sequino
23 ,4
, A. Sergeev
219
, Y. Setyawati
110
, T. Sha
ff
er
63
, M. S. Shahriar
15
, B. Shams
167
, L. Shao
199
,
A. Sharma
29 ,97
, P. Sharma
83
, P. Shawhan
100
, N. S. Shcheblanov
238
, S. Shibagaki
124
, M. Shikauchi
111
, R. Shimizu
21
, T. Shimoda
25
, K. Shimode
190
,
H. Shinkai
277
, T. Shishido
44
, A. Shoda
20
, D. H. Shoemaker
66
, D. M. Shoemaker
164
, S. ShyamSundar
83
, M. Sieniawska
99
, D. Sigg
63
,
L. P. Singer
108
, D. Singh
145
, N. Singh
99
, A. Singha
151 ,49
, A. M. Sintes
141
, V. Sipala
114 ,115
, V. Skliris
17
, B. J. J. Slagmolen
8
, T. J. Slaven-Blair
82
,
J. Smetana
14
, J. R. Smith
37
, R. J. E. Smith
5
, J. Soldateschi
278 ,279 ,46
, S. N. Somala
280
, K. Somiya
217
, E. J. Son
224
, K. Soni
11
, S. Soni
2
, V. Sordini
133
,
F. Sorrentino
81
, N. Sorrentino
70 ,18
, H. Sotani
281
, R. Soulard
91
, T. Souradeep
268 ,11
, E. Sowell
144
, V. Spagnuolo
151 ,49
, A. P. Spencer
65
, M. Spera
73 ,74
,
R. Srinivasan
91
, A. K. Srivastava
76
, V. Srivastava
57
, K. Staats
15
, C. Stachie
91
, D. A. Steer
33
, J. Steinlechner
151 ,49
, S. Steinlechner
151 ,49
,
D. J. Stops
14
, M. Stover
170
, K. A. Strain
65
, L. C. Strang
113
, G. Stratta
282 ,46
, A. Strunk
63
, R. Sturani
264
, A. L. Stuver
119
, S. Sudhagar
11
, V. Sudhir
66
,
R. Sugimoto
283 ,204
, H. G. Suh
7
, T. Z. Summerscales
284
, H. Sun
82
, L. Sun
8
, S. Sunil
76
, A. Sur
77
, J. Suresh
111 ,34
, P. J. Sutton
17
, T. Suzuki
173
,
T. Suzuki
34
, B. L. Swinkels
49
, M. J. Szczepa
́
nczyk
68
, P. Szewczyk
99
, M. Tacca
49
, H.vTagoshi
34
, S. C. Tait
65
, H. Takahashi
285
, R. Takahashi
20
,
A. Takamori
36
, S. Takano
25
, H. Takeda
25
, M. Takeda
202
, C. J. Talbot
29
, C. Talbot
1
, H. Tanaka
286
, K. Tanaka
202
, K. Tanaka
286
, T. Tanaka
34
,
T. Tanaka
271
, A. J. Tanasijczuk
48
, S. Tanioka
20 ,44
, D. B. Tanner
68
, D. Tao
1
, L. Tao
68
, E. N. Tapia San Martin
20
, E. N. Tapia San Martín
49
,
C. Taranto
116
, J. D. Tasson
191
, S. Telada
287
, R. Tenorio
141
, J. E. Terhune
119
, L. Terkowski
121
, M. P. Thirugnanasambandam
11
, M. Thomas
6
,
P. Thomas
63
, J. E. Thompson
17
, S. R. Thondapu
83
, K. A. Thorne
6
, E. Thrane
5
, Shubhanshu Tiwari
157
, Srishti Tiwari
11
, V. Tiwari
17
,
A. M. Toivonen
59
, K. Toland
65
, A. E. Tolley
152
, T. Tomaru
20
, Y. Tomigami
202
, T. Tomura
190
, M. Tonelli
70 ,18
, A. Torres-Forné
120
,
C. I. Torrie
1
, I. Tosta e Melo
114 ,115
, D. Töyrä
8
, A. Trapananti
248 ,71
, F. Travasso
71 ,248
, G. Traylor
6
, M. Trevor
100
, M. C. Tringali
39
,
A. Tripathee
182
, L. Troiano
288 ,93
, A. Trovato
33
, L. Trozzo
4 ,190
, R. J. Trudeau
1
, D. S. Tsai
123
, D. Tsai
123
, K. W. Tsang
49 ,289 ,110
, T. Tsang
290
,
J-S. Tsao
196
, M. Tse
66
, R. Tso
129
, K. Tsubono
25
, S. Tsuchida
202
, L. Tsukada
111
, D. Tsuna
111
, T. Tsutsui
111
, T. Tsuzuki
21
, K. Turbang
291 ,207
,
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91
, D. Tuyenbayev
202
, A. S. Ubhi
14
, N. Uchikata
34
, T. Uchiyama
190
, R. P. Udall
1
, A. Ueda
185
, T. Uehara
292 ,293
, K. Ueno
111
,
G. Ueshima
294
, C. S. Unnikrishnan
179
, F. Uraguchi
21
, A. L. Urban
2
, T. Ushiba
190
, A. Utina
151 ,49
, H. Vahlbruch
9 ,10
, G. Vajente
1
, A. Vajpeyi
5
,
G. Valdes
183
, M. Valentini
87 ,88
, V. Valsan
7
, N. van Bakel
49
, M. van Beuzekom
49
, J. F. J. van den Brand
151 ,295 ,49
, C. Van Den Broeck
110 ,49
,
D. C. Vander-Hyde
57
, L. van der Schaaf
49
, J. V. van Heijningen
48
, J. Vanosky
1
, M. H. P. M. van Putten
296
, N. van Remortel
207
, M. Vardaro
241 ,49
,
A. F. Vargas
113
, V. Varma
177
, M. Vasúth
67
, A. Vecchio
14
, G. Vedovato
74
, J. Veitch
65
, P. J. Veitch
79
, J. Venneberg
9 ,10
, G. Venugopalan
1
,
D. Verkindt
28
, P. Verma
231
, Y. Verma
83
, D. Veske
42
, F. Vetrano
45
, A. Viceré
45 ,46
, S. Vidyant
57
, A. D. Viets
247
, A. Vijaykumar
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104
, J.-Y. Vinet
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, A. Virtuoso
186 ,31
, S. Vitale
66
, T. Vo
57
, H. Vocca
72 ,71
, E. R. G. von Reis
63
, J. S. A. von Wrangel
9 ,10
,
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63
, S. P. Vyatchanin
86
, L. E. Wade
170
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170
, K. J. Wagner
122
, R. C. Walet
49
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53
, G. S. Wallace
29
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1
,
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7
, J. Wang
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, W. H. Wang
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8
, J. Warner
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, M. Was
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, T. Washimi
20
, N. Y. Washington
1
, J. Watchi
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,
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63
, S. A. Webster
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, M. Weinert
9 ,10
, A. J. Weinstein
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, R. Weiss
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, C. M. Weller
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, F. Wellmann
9 ,10
, L. Wen
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, P. Weßels
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, K. Wette
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,
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, D. D. White
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, B. F. Whiting
68
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9 ,10
, D. Williams
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, M. J. Williams
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, A. R. Williamson
152
, J. L. Willis
1
,
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, D. J. Wilson
137
, W. Winkler
9 ,10
, C. C. Wipf
1
, T. Wlodarczyk
101
, G. Woan
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, J. Woehler
9 ,10
, J. K. Wo
ff
ord
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, I. C. F. Wong
105
,
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130
, D. S. Wu
9 ,10
, H. Wu
130
, S. Wu
130
, D. M. Wysocki
7
, L. Xiao
1
, W-R. Xu
196
, T. Yamada
286
, H. Yamamoto
1
, K. Yamamoto
214
,
K. Yamamoto
286
, T. Yamamoto
190
, K. Yamashita
201
, R. Yamazaki
198
, F. W. Yang
167
, L. Yang
162
, Y. Yang
297
, Yang Yang
68
, Z. Yang
59
, M. J. Yap
8
,
D. W. Yeeles
17
, A. B. Yelikar
122
, M. Ying
123
, K. Yokogawa
201
, J. Yokoyama
26 ,25
, T. Yokozawa
190
, J. Yoo
177
, T. Yoshioka
201
, Hang Yu
129
,
H. Yu
66
, H. Yuzurihara
34
, A. Zadro ̇zny
231
, M. Zanolin
32
, S. Zeidler
298
, T. Zelenova
39
, J.-P. Zendri
74
, M. Zevin
158
, M. Zhan
174
, H. Zhang
196
,
J. Zhang
82
, L. Zhang
1
, T. Zhang
14
, Y. Zhang
183
, C. Zhao
82
, G. Zhao
142
, Y. Zhao
20
, Y. Zhao
167
, R. Zhou
192
, Z. Zhou
15
, X. J. Zhu
5
, Z.-H. Zhu
112
,
A. B. Zimmerman
164
, M. E. Zucker
1,66
, J. Zweizig
1
(The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration)
(A
ffi
liations can be found after the references)
Received 2 June 2021
/
Accepted 9 September 2021
A84, page 3 of 25
A&A 659, A84 (2022)
ABSTRACT
Intermediate-mass black holes (IMBHs) span the approximate mass range 100
−
10
5
M
, between black holes (BHs) that formed by stellar collapse
and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the
terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH
binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a
binary merger of mass
∼
150
M
providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH
binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none
are su
ffi
ciently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the
combined search using a suite of IMBH binary signals obtained via numerical relativity, including the e
ff
ects of spins misaligned with the binary
orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH
binary of total mass 200
M
and e
ff
ective aligned spin 0.8 at 0.056 Gpc
−
3
yr
−
1
(90% confidence), a factor of 3.5 more constraining than previous
LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc
−
3
yr
−
1
.
Key words.
gravitational waves – stars: black holes – black hole physics
1. Introduction
Black holes are classified according to their masses: stellar-mass
black holes (BHs) are those with mass below
∼
100
M
, formed
by stellar collapse, while supermassive BHs (Ferrarese & Ford
2005) at the centers of galaxies have masses above 10
5
M
.
Between stellar-mass and supermassive BHs is the realm
of IMBHs and BHs with masses in the 100
−
10
5
M
range
(van der Marel 2004; Miller & Colbert 2004; Ebisuzaki et al.
2001; Koliopanos 2017; Inayoshi et al. 2020).
Stellar evolution models suggest that BHs with masses up to
∼
65
M
are the result of core-collapse in massive stars (Woosley
2017, 2019; Giacobbo et al. 2018; Farmer et al. 2019, 2020;
Mapelli et al. 2020). The final fate of the star is determined
by the mass of the helium core alone. Stars with helium core
masses in the
∼
32
−
64
M
range undergo pulsational pair insta-
bility, leaving behind remnant BHs of masses below
∼
65
M
(Fowler & Hoyle 1964; Barkat et al. 1967). When the helium
core mass is in the
∼
64
−
135
M
range pair-instability drives the
supernova explosion and leaves no remnant; while stars with a
helium core mass greater than
∼
135
M
are expected to directly
collapse to intermediate-mass BHs. Thus, pair-instability (PI)
prevents the formation of heavier BHs from core-collapse, and
suggests a mass gap between
∼
65
−
120
M
in the BH popula-
tion known as PI supernova (PISN) mass gap (Bond et al. 1984;
Woosley et al. 2007; Woosley & Heger 2021). Possible IMBH
formation channels also include the direct collapse of massive
first-generation, low-metallicity Population III stars (Fryer et al.
2001; Heger et al. 2003; Spera & Mapelli 2017; Madau & Rees
2001; Heger & Woosley 2002), and multiple, hierarchical colli-
sions of stars in dense young star clusters (Miller & Hamilton
2002; O’Leary et al. 2006; Giersz et al. 2015; Mapelli 2016),
among others. It is not currently known how supermassive black
holes form. The hierarchical merger of IMBH systems in a dense
environment is among the putative formation channels for super-
massive BHs (King & Dehnen 2005; Volonteri 2010; Mezcua
2017; Koliopanos 2017).
Several IMBH candidates are suggested by electromag-
netic observations, but these lack conclusive confirmation
(Greene et al. 2020). Observations include direct kinematical
measurement of the mass of the central BH in massive star
clusters and galaxies (Mezcua 2017; Miller & Hamilton 2002;
Atakan Gurkan et al. 2004; Anderson & van der Marel 2010;
Baumgardt et al. 2003; Pasham et al. 2015; Vitral & Mamon
2021). Other possible evidence of IMBHs includes extrapolation
of scaling relations between the masses of host galaxies and their
central supermassive BH to the mass range of globular clusters
(Graham 2012; Graham & Scott 2013; Kormendy & Ho 2013).
In addition, observations of characteristic imprints on the sur-
face brightness, mass-to-light ratio and
/
or line-of-sight veloci-
ties also suggest that dense globular clusters harbour IMBHs
(van den Bosch et al. 2006; Gebhardt et al. 2005; Noyola et al.
2008; Lützgendorf et al. 2011; Kızıltan et al. 2017). Controversy
exists regarding the interpretation of these observations, as some
of them can also be explained by a high concentration of
stellar-mass BHs or the presence of binaries (Baumgardt et al.
2003; Anderson & van der Marel 2010; Lanzoni et al. 2013).
Empirical mass scaling relations of quasi-periodic oscillations
in luminous X-ray sources have also provided evidence of
IMBHs (Remillard & McClintock 2006). Ultraluminous X-ray
sources exceed the Eddington luminosity of an accreting stellar-
mass BH (Kaaret et al. 2017; Farrell et al. 2009). An accreting
IMBH is a favored explanation in several cases (Kaaret et al.
2001; Miller & Colbert 2004). However, neutron stars or stellar-
mass BH emitting above their Eddington luminosity could also
account for such observations (Bachetti et al. 2014; Israel et al.
2017). The strongest IMBH candidate among them is HLX-
1, an hyper-luminous X-ray source indicating an IMBH
mass of
∼
0
.
3
−
30
×
10
4
M
(Farrell et al. 2009; Godet et al.
2009; Servillat et al. 2011; Webb et al. 2012; Cseh et al. 2015;
Soria et al. 2012). In Lin et al. (2018), an intermediate-mass
black hole candidate was found in a tidal disruption event in a
massive star cluster. More recently Paynter et al. (2021) claimed
an IMBH detection through a gravitationally lensed gamma-ray
burst.
The Advanced LIGO (Aasi et al. 2015) and Advanced Virgo
(Acernese et al. 2015) interferometric gravitational wave (GW)
detectors completed three observing runs between September
2015 and March 2020. The third observing run of Advanced
LIGO and Advanced Virgo, O3, extended from April 1, 2019,
15:00 UTC to March 27, 2020 17:00 UTC. The recently released
second gravitational-wave transient catalog provided a com-
prehensive summary of significant compact binary coalescence
events observed up to October 1st, 2019 (Abbott et al. 2021a),
reporting a total of 50 events. The corresponding binary black
hole (BBH) population analysis of Abbott et al. (2021b) indi-
cates that 99% of primary BH masses lie below
m
99%
∼
60
M
;
thus, the large majority of merging BHs have masses below a
limit of
∼
65
M
, consistently with expectations from PI.
Near the beginning of O3, an unusually high mass black hole
coalescence, GW190521 (Abbott et al. 2020a), was detected.
This GW signal was consistent with a coalescence of black holes
of 85
+
21
−
14
M
and 66
+
17
−
18
M
which resulted in a remnant black
hole of 142
+
28
−
16
M
falling in the mass range of intermediate-mass
A84, page 4 of 25
LVK: Search for intermediate-mass black hole binaries in the O3 run
black holes
1
. GW190521 provided the first conclusive evidence
for the formation of an IMBH below 10
3
M
. It is a massive
binary black hole system with an IMBH remnant and a primary
BH in the PISN mass gap with high confidence (Abbott et al.
2020b; although, see Fishbach & Holz 2020; Nitz & Capano
2021 for an alternative interpretation). The discovery triggered
a variety of investigations regarding the evolution models and
the subsequent mass gap in the BH population. It also suggested
the possibility of the formation of massive BHs (
>
100
M
)
via a hierarchical merger scenario in a dense environment
(Abbott et al. 2020b; Kimball et al. 2021).
The Advanced LIGO and Advanced Virgo detectors are sen-
sitive to the lower end of the IMBH binary mass range, poten-
tially making IMBHs detectable out to cosmological distances,
as is evident from GW190521. Observation of IMBH binary sys-
tems are not only interesting for massive BH formation chan-
nels, but they act as a perfect laboratory to test general relativity
(Abbott et al. 2016a; Yunes et al. 2016; Yunes & Siemens 2013;
Gair et al. 2013). Massive BH coalescences produce louder
mergers and ringdown signals in the sensitive band of the
advanced GW detectors. Furthermore, these can display promi-
nent higher order modes that confer GWs a more complex mor-
phology that can significantly deviate from a canonical chirp
(Calderon Bustillo et al. 2020). Observations of higher order
modes help to test general relativity and fundamental proper-
ties of BHs such as the no-hair theorem (Kamaretsos et al. 2012;
Meidam et al. 2014; Thrane et al. 2017; Carullo et al. 2018) and
BH kick measurements (Gonzalez et al. 2007; Campanelli et al.
2007; Calderón Bustillo et al. 2018). These IMBHs might be
multiband events observable by both LIGO and Virgo and
LISA (Amaro-Seoane et al. 2017), and could provide novel
probes of cosmology and contribute to the stochastic back-
ground (Fregeau et al. 2006; Miller 2009; Jani et al. 2020;
Ezquiaga & Holz 2021).
The GW signal from a massive BBH coalescence is evi-
dent as a short-duration waveform with little inspiral and mostly
merger-ringdown signal, falling in the low-frequency region of
the advanced detectors. With initial GW detectors (Abadie et al.
2012; Aasi et al. 2014), the IMBH binary searches were
restricted in order to probe the merger-ringdown phase of the
coalescing BBH system using the model waveform-independent
coherent WaveBurst (cWB) (Klimenko & Mitselmakher 2004;
Klimenko et al. 2005, 2006) and a ringdown templated search
(Aasi et al. 2014). Improvement in the detector sensitivity at low
frequencies in the advanced era made IMBH binaries a target
for a matched filtering search that would probe the short inspiral
phase. In Abbott et al. (2017a), we used a combined search with
the matched filtering GstLAL (Messick et al. 2017; Hanna et al.
2020; Sachdev et al. 2019) search and model-independent cWB
(Klimenko et al. 2011, 2016). This combined search was fur-
ther extended with an additional matched filtering PyCBC
search (Usman et al. 2016; Allen 2005; Dal Canton et al. 2014;
Nitz et al. 2017) in Abbott et al. (2019a) using the data from the
first two observing runs. No significant IMBH binary event was
found in these searches.
While all the previous matched filtering searches were
generic BBH searches, the improvements in the detector sensi-
tivity at low frequencies and the IMBH merger signals’ short
1
The parameter estimated values for GW190521 reported in GWTC-2
are slightly di
ff
erent from that of the detection paper. The estimation in
the detection paper is based on the NRSur7dq4 waveform model, and
GWTC-2 values are obtained from the estimates averaged over three
waveforms; SEOBNRv4PHM, NRSur7dq4, and IMRPhenomPv3HM,
respectively.
duration nature motivated us to use matched filter searches
targeted to the IMBH mass-spin parameter space. We carried
out an IMBH binary search using the entire year-long third
observing run, O3, of the Advanced LIGO and Advanced Virgo
detector networks with a combined search using three search
algorithms: two matched-filtering-based IMBH binary searches
using the PyCBC and GstLAL libraries, and the minimally mod-
eled time-frequency-based cWB search. We searched for mas-
sive binary systems with at least one component above the
expected PISN mass gap limit of 65
M
, and with an IMBH rem-
nant. GW190521 remains the most significant candidate in the
combined search; no other event is comparably significant. We
provide the results from the combined search with the next most
significant events and follow-up investigations to assess their
origins.
The increased sensitivity of the O3 run allows us to set more
stringent bounds on the binary merger rate density. The lack of a
confirmed IMBH population as well as possible formation chan-
nels of IMBH distinct from those of stellar-mass BHs preclude
us from using an overall mass model for the IMBH population.
Thus, we confined all the upper limit studies to a suite of dis-
crete points in the IMBH parameter space. We incorporated more
detailed physics in selecting the suite of IMBH binary wave-
forms as compared to earlier upper limit studies. In Abbott et al.
(2017a), we simulated a limited set of discrete mass and aligned-
spin binary waveforms in the first advanced detector observation
data to obtain upper limits on the merger rate. The study with the
first two observation runs used the most realistic numerical rela-
tivity (NR) simulation set with aligned spins for the upper limit
study (Abbott et al. 2019a). The most recent stringent merger
rate upper limit is 0.2 Gpc
−
3
yr
−
1
; this is for the equal mass
binary system with a component mass of 100
M
and component
spins of dimensionless magnitude 0.8 aligned with the binary
orbital angular momentum. Recently, Chandra et al. (2020) used
IMBH binary systems with generically spinning BHs with total
masses from 210
−
500
M
and obtained a most stringent upper
limit of 0.28 Gpc
−
3
yr
−
1
for equal-mass binaries with total mass
of 210
M
.
We used a suite of NR simulations of GW emission from an
IMBH binary system with generically spinning BHs in order to
estimate our search sensitivity over the O3 data. We placed the
most stringent 90% merger rate upper limit on equal mass and
aligned spin BH binary of total mass 200
M
and with individ-
ual BH spins of 0.8 as 0.056 Gpc
−
3
yr
−
1
. The revised limit is a
factor of
∼
3
.
5 more stringent than that obtained with the first
two observing runs. We also updated the merger rate for systems
compatible with the source parameters of GW190521 (first esti-
mated in Abbott et al. 2020b) at 0
.
08
+
0
.
19
−
0
.
07
Gpc
−
3
yr
−
1
using the
combined search method applied to simulated signals injected
over the entire O3 data.
The paper is organized as follows: Sect. 2 summarizes the
data being used for the search. Section 3 summarizes the com-
bined search approach from the results from three distinct IMBH
binary search algorithms. Section 4 discusses the search results
and follow-up of the most significant candidate events. Section 5
provides a detailed discussion about the NR GW injection set
used and the rate upper limits studied including the updated rate
on the most significant GW190521-like systems.
2. Data summary
We carried out the analysis using O3 data from both LIGO detec-
tors (LHO-LIGO Hanford Observatory and LLO-LIGO Liv-
ingston Observatory) and the Virgo detector. We conditioned the
A84, page 5 of 25