Draft version January 7, 2019
Typeset using L
A
T
E
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twocolumn
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Binary Black Hole Population Properties Inferred from the First and Second Observing Runs of Advanced LIGO and
Advanced Virgo
B. P. Abbott,
1
R. Abbott,
1
T. D. Abbott,
2
S. Abraham,
3
F. Acernese,
4, 5
K. Ackley,
6
C. Adams,
7
R. X. Adhikari,
1
V. B. Adya,
8, 9
C. Affeldt,
8, 9
M. Agathos,
10
K. Agatsuma,
11
N. Aggarwal,
12
O. D. Aguiar,
13
L. Aiello,
14, 15
A. Ain,
3
P. Ajith,
16
G. Allen,
17
A. Allocca,
18, 19
M. A. Aloy,
20
P. A. Altin,
21
A. Amato,
22
A. Ananyeva,
1
S. B. Anderson,
1
W. G. Anderson,
23
S. V. Angelova,
24
S. Antier,
25
S. Appert,
1
K. Arai,
1
M. C. Araya,
1
J. S. Areeda,
26
M. Ar
`
ene,
27
N. Arnaud,
25, 28
K. G. Arun,
29
S. Ascenzi,
30, 31
G. Ashton,
6
S. M. Aston,
7
P. Astone,
32
F. Aubin,
33
P. Aufmuth,
9
K. AultONeal,
34
C. Austin,
2
V. Avendano,
35
A. Avila-Alvarez,
26
S. Babak,
36, 27
P. Bacon,
27
F. Badaracco,
14, 15
M. K. M. Bader,
37
S. Bae,
38
P. T. Baker,
39
F. Baldaccini,
40, 41
G. Ballardin,
28
S. W. Ballmer,
42
S. Banagiri,
43
J. C. Barayoga,
1
S. E. Barclay,
44
B. C. Barish,
1
D. Barker,
45
K. Barkett,
46
S. Barnum,
12
F. Barone,
4, 5
B. Barr,
44
L. Barsotti,
12
M. Barsuglia,
27
D. Barta,
47
J. Bartlett,
45
I. Bartos,
48
R. Bassiri,
49
A. Basti,
18, 19
M. Bawaj,
50, 41
J. C. Bayley,
44
M. Bazzan,
51, 52
B. B
́
ecsy,
53
M. Bejger,
27, 54
I. Belahcene,
25
A. S. Bell,
44
D. Beniwal,
55
B. K. Berger,
49
G. Bergmann,
8, 9
S. Bernuzzi,
56, 57
J. J. Bero,
58
C. P. L. Berry,
59
D. Bersanetti,
60
A. Bertolini,
37
J. Betzwieser,
7
R. Bhandare,
61
J. Bidler,
26
I. A. Bilenko,
62
S. A. Bilgili,
39
G. Billingsley,
1
J. Birch,
7
R. Birney,
24
O. Birnholtz,
58
S. Biscans,
1, 12
S. Biscoveanu,
6
A. Bisht,
9
M. Bitossi,
28, 19
M. A. Bizouard,
25
J. K. Blackburn,
1
C. D. Blair,
7
D. G. Blair,
63
R. M. Blair,
45
S. Bloemen,
64
N. Bode,
8, 9
M. Boer,
65
Y. Boetzel,
66
G. Bogaert,
65
F. Bondu,
67
E. Bonilla,
49
R. Bonnand,
33
P. Booker,
8, 9
B. A. Boom,
37
C. D. Booth,
68
R. Bork,
1
V. Boschi,
28
S. Bose,
69, 3
K. Bossie,
7
V. Bossilkov,
63
J. Bosveld,
63
Y. Bouffanais,
27
A. Bozzi,
28
C. Bradaschia,
19
P. R. Brady,
23
A. Bramley,
7
M. Branchesi,
14, 15
J. E. Brau,
70
T. Briant,
71
J. H. Briggs,
44
F. Brighenti,
72, 73
A. Brillet,
65
M. Brinkmann,
8, 9
V. Brisson,
25,
∗
P. Brockill,
23
A. F. Brooks,
1
D. D. Brown,
55
S. Brunett,
1
A. Buikema,
12
T. Bulik,
74
H. J. Bulten,
75, 37
A. Buonanno,
36, 76
R. Buscicchio,
11
D. Buskulic,
33
C. Buy,
27
R. L. Byer,
49
M. Cabero,
8, 9
L. Cadonati,
77
G. Cagnoli,
22, 78
C. Cahillane,
1
J. Calder
́
on Bustillo,
6
T. A. Callister,
1
E. Calloni,
79, 5
J. B. Camp,
80
W. A. Campbell,
6
M. Canepa,
81, 60
K. C. Cannon,
82
H. Cao,
55
J. Cao,
83
E. Capocasa,
27
F. Carbognani,
28
S. Caride,
84
M. F. Carney,
59
G. Carullo,
18
J. Casanueva Diaz,
19
C. Casentini,
30, 31
S. Caudill,
37
M. Cavagli
`
a,
85
F. Cavalier,
25
R. Cavalieri,
28
G. Cella,
19
P. Cerd
́
a-Dur
́
an,
20
G. Cerretani,
18, 19
E. Cesarini,
86, 31
O. Chaibi,
65
K. Chakravarti,
3
S. J. Chamberlin,
87
M. Chan,
44
S. Chao,
88
P. Charlton,
89
E. A. Chase,
59
E. Chassande-Mottin,
27
D. Chatterjee,
23
M. Chaturvedi,
61
K. Chatziioannou,
90
B. D. Cheeseboro,
39
H. Y. Chen,
91
X. Chen,
63
Y. Chen,
46
H.-P. Cheng,
48
C. K. Cheong,
92
H. Y. Chia,
48
A. Chincarini,
60
A. Chiummo,
28
G. Cho,
93
H. S. Cho,
94
M. Cho,
76
N. Christensen,
65, 95
Q. Chu,
63
S. Chua,
71
K. W. Chung,
92
S. Chung,
63
G. Ciani,
51, 52
A. A. Ciobanu,
55
R. Ciolfi,
96, 97
F. Cipriano,
65
A. Cirone,
81, 60
F. Clara,
45
J. A. Clark,
77
P. Clearwater,
98
F. Cleva,
65
C. Cocchieri,
85
E. Coccia,
14, 15
P.-F. Cohadon,
71
D. Cohen,
25
R. Colgan,
99
M. Colleoni,
100
C. G. Collette,
101
C. Collins,
11
L. R. Cominsky,
102
M. Constancio Jr.,
13
L. Conti,
52
S. J. Cooper,
11
P. Corban,
7
T. R. Corbitt,
2
I. Cordero-Carri
́
on,
103
K. R. Corley,
99
N. Cornish,
53
A. Corsi,
84
S. Cortese,
28
C. A. Costa,
13
R. Cotesta,
36
M. W. Coughlin,
1
S. B. Coughlin,
68, 59
J.-P. Coulon,
65
S. T. Countryman,
99
P. Couvares,
1
P. B. Covas,
100
E. E. Cowan,
77
D. M. Coward,
63
M. J. Cowart,
7
D. C. Coyne,
1
R. Coyne,
104
J. D. E. Creighton,
23
T. D. Creighton,
105
J. Cripe,
2
M. Croquette,
71
S. G. Crowder,
106
T. J. Cullen,
2
A. Cumming,
44
L. Cunningham,
44
E. Cuoco,
28
T. Dal Canton,
80
G. D
́
alya,
107
S. L. Danilishin,
8, 9
S. D’Antonio,
31
K. Danzmann,
9, 8
A. Dasgupta,
108
C. F. Da Silva Costa,
48
L. E. H. Datrier,
44
V. Dattilo,
28
I. Dave,
61
M. Davier,
25
D. Davis,
42
E. J. Daw,
109
D. DeBra,
49
M. Deenadayalan,
3
J. Degallaix,
22
M. De Laurentis,
79, 5
S. Del
́
eglise,
71
W. Del Pozzo,
18, 19
L. M. DeMarchi,
59
N. Demos,
12
T. Dent,
8, 9, 110
R. De Pietri,
111, 57
J. Derby,
26
R. De Rosa,
79, 5
C. De Rossi,
22, 28
R. DeSalvo,
112
O. de Varona,
8, 9
S. Dhurandhar,
3
M. C. D
́
ıaz,
105
T. Dietrich,
37
L. Di Fiore,
5
M. Di Giovanni,
113, 97
T. Di Girolamo,
79, 5
A. Di Lieto,
18, 19
B. Ding,
101
S. Di Pace,
114, 32
I. Di Palma,
114, 32
F. Di Renzo,
18, 19
A. Dmitriev,
11
Z. Doctor,
91
F. Donovan,
12
K. L. Dooley,
68, 85
S. Doravari,
8, 9
I. Dorrington,
68
T. P. Downes,
23
M. Drago,
14, 15
J. C. Driggers,
45
Z. Du,
83
J.-G. Ducoin,
25
P. Dupej,
44
S. E. Dwyer,
45
P. J. Easter,
6
T. B. Edo,
109
M. C. Edwards,
95
A. Effler,
7
P. Ehrens,
1
J. Eichholz,
1
S. S. Eikenberry,
48
M. Eisenmann,
33
R. A. Eisenstein,
12
R. C. Essick,
91
H. Estelles,
100
D. Estevez,
33
Z. B. Etienne,
39
T. Etzel,
1
M. Evans,
12
T. M. Evans,
7
V. Fafone,
30, 31, 14
H. Fair,
42
S. Fairhurst,
68
X. Fan,
83
S. Farinon,
60
B. Farr,
70
W. M. Farr,
11
E. J. Fauchon-Jones,
68
M. Favata,
35
M. Fays,
109
M. Fazio,
115
C. Fee,
116
J. Feicht,
1
M. M. Fejer,
49
F. Feng,
27
A. Fernandez-Galiana,
12
I. Ferrante,
18, 19
E. C. Ferreira,
13
T. A. Ferreira,
13
F. Ferrini,
28
F. Fidecaro,
18, 19
I. Fiori,
28
D. Fiorucci,
27
M. Fishbach,
91
R. P. Fisher,
42, 117
J. M. Fishner,
12
M. Fitz-Axen,
43
R. Flaminio,
33, 118
M. Fletcher,
44
E. Flynn,
26
H. Fong,
90
J. A. Font,
20, 119
P. W. F. Forsyth,
21
J.-D. Fournier,
65
S. Frasca,
114, 32
F. Frasconi,
19
Z. Frei,
107
A. Freise,
11
R. Frey,
70
V. Frey,
25
P. Fritschel,
12
V. V. Frolov,
7
P. Fulda,
48
M. Fyffe,
7
H. A. Gabbard,
44
B. U. Gadre,
3
S. M. Gaebel,
11
J. R. Gair,
120
L. Gammaitoni,
40
M. R. Ganija,
55
S. G. Gaonkar,
3
A. Garcia,
26
C. Garc
́
ıa-Quir
́
os,
100
F. Garufi,
79, 5
B. Gateley,
45
S. Gaudio,
34
G. Gaur,
121
V. Gayathri,
122
G. Gemme,
60
E. Genin,
28
A. Gennai,
19
D. George,
17
J. George,
61
L. Gergely,
123
V. Germain,
33
S. Ghonge,
77
Abhirup Ghosh,
16
Archisman Ghosh,
37
S. Ghosh,
23
arXiv:1811.12940v3 [astro-ph.HE] 3 Jan 2019
2
B. Giacomazzo,
113, 97
J. A. Giaime,
2, 7
K. D. Giardina,
7
A. Giazotto,
19,
†
K. Gill,
34
G. Giordano,
4, 5
L. Glover,
112
P. Godwin,
87
E. Goetz,
45
R. Goetz,
48
B. Goncharov,
6
G. Gonz
́
alez,
2
J. M. Gonzalez Castro,
18, 19
A. Gopakumar,
124
M. L. Gorodetsky,
62
S. E. Gossan,
1
M. Gosselin,
28
R. Gouaty,
33
A. Grado,
125, 5
C. Graef,
44
M. Granata,
22
A. Grant,
44
S. Gras,
12
P. Grassia,
1
C. Gray,
45
R. Gray,
44
G. Greco,
72, 73
A. C. Green,
11, 48
R. Green,
68
E. M. Gretarsson,
34
P. Groot,
64
H. Grote,
68
S. Grunewald,
36
P. Gruning,
25
G. M. Guidi,
72, 73
H. K. Gulati,
108
Y. Guo,
37
A. Gupta,
87
M. K. Gupta,
108
E. K. Gustafson,
1
R. Gustafson,
126
L. Haegel,
100
O. Halim,
15, 14
B. R. Hall,
69
E. D. Hall,
12
E. Z. Hamilton,
68
G. Hammond,
44
M. Haney,
66
M. M. Hanke,
8, 9
J. Hanks,
45
C. Hanna,
87
M. D. Hannam,
68
O. A. Hannuksela,
92
J. Hanson,
7
T. Hardwick,
2
K. Haris,
16
J. Harms,
14, 15
G. M. Harry,
127
I. W. Harry,
36
C.-J. Haster,
90
K. Haughian,
44
F. J. Hayes,
44
J. Healy,
58
A. Heidmann,
71
M. C. Heintze,
7
H. Heitmann,
65
P. Hello,
25
G. Hemming,
28
M. Hendry,
44
I. S. Heng,
44
J. Hennig,
8, 9
A. W. Heptonstall,
1
Francisco Hernandez Vivanco,
6
M. Heurs,
8, 9
S. Hild,
44
T. Hinderer,
128, 37, 129
D. Hoak,
28
S. Hochheim,
8, 9
D. Hofman,
22
A. M. Holgado,
17
N. A. Holland,
21
K. Holt,
7
D. E. Holz,
91
P. Hopkins,
68
C. Horst,
23
J. Hough,
44
E. J. Howell,
63
C. G. Hoy,
68
A. Hreibi,
65
E. A. Huerta,
17
D. Huet,
25
B. Hughey,
34
M. Hulko,
1
S. Husa,
100
S. H. Huttner,
44
T. Huynh-Dinh,
7
B. Idzkowski,
74
A. Iess,
30, 31
C. Ingram,
55
R. Inta,
84
G. Intini,
114, 32
B. Irwin,
116
H. N. Isa,
44
J.-M. Isac,
71
M. Isi,
1
B. R. Iyer,
16
K. Izumi,
45
T. Jacqmin,
71
S. J. Jadhav,
130
K. Jani,
77
N. N. Janthalur,
130
P. Jaranowski,
131
A. C. Jenkins,
132
J. Jiang,
48
D. S. Johnson,
17
A. W. Jones,
11
D. I. Jones,
133
R. Jones,
44
R. J. G. Jonker,
37
L. Ju,
63
J. Junker,
8, 9
C. V. Kalaghatgi,
68
V. Kalogera,
59
B. Kamai,
1
S. Kandhasamy,
85
G. Kang,
38
J. B. Kanner,
1
S. J. Kapadia,
23
S. Karki,
70
K. S. Karvinen,
8, 9
R. Kashyap,
16
M. Kasprzack,
1
S. Katsanevas,
28
E. Katsavounidis,
12
W. Katzman,
7
S. Kaufer,
9
K. Kawabe,
45
N. V. Keerthana,
3
F. K
́
ef
́
elian,
65
D. Keitel,
44
R. Kennedy,
109
J. S. Key,
134
F. Y. Khalili,
62
H. Khan,
26
I. Khan,
14, 31
S. Khan,
8, 9
Z. Khan,
108
E. A. Khazanov,
135
M. Khursheed,
61
N. Kijbunchoo,
21
Chunglee Kim,
136
J. C. Kim,
137
K. Kim,
92
W. Kim,
55
W. S. Kim,
138
Y.-M. Kim,
139
C. Kimball,
59
E. J. King,
55
P. J. King,
45
M. Kinley-Hanlon,
127
R. Kirchhoff,
8, 9
J. S. Kissel,
45
L. Kleybolte,
140
J. H. Klika,
23
S. Klimenko,
48
T. D. Knowles,
39
P. Koch,
8, 9
S. M. Koehlenbeck,
8, 9
G. Koekoek,
37, 141
S. Koley,
37
V. Kondrashov,
1
A. Kontos,
12
N. Koper,
8, 9
M. Korobko,
140
W. Z. Korth,
1
I. Kowalska,
74
D. B. Kozak,
1
V. Kringel,
8, 9
N. Krishnendu,
29
A. Kr
́
olak,
142, 143
G. Kuehn,
8, 9
A. Kumar,
130
P. Kumar,
144
R. Kumar,
108
S. Kumar,
16
L. Kuo,
88
A. Kutynia,
142
S. Kwang,
23
B. D. Lackey,
36
K. H. Lai,
92
T. L. Lam,
92
M. Landry,
45
B. B. Lane,
12
R. N. Lang,
145
J. Lange,
58
B. Lantz,
49
R. K. Lanza,
12
A. Lartaux-Vollard,
25
P. D. Lasky,
6
M. Laxen,
7
A. Lazzarini,
1
C. Lazzaro,
52
P. Leaci,
114, 32
S. Leavey,
8, 9
Y. K. Lecoeuche,
45
C. H. Lee,
94
H. K. Lee,
146
H. M. Lee,
147
H. W. Lee,
137
J. Lee,
93
K. Lee,
44
J. Lehmann,
8, 9
A. Lenon,
39
N. Leroy,
25
N. Letendre,
33
Y. Levin,
6, 99
J. Li,
83
K. J. L. Li,
92
T. G. F. Li,
92
X. Li,
46
F. Lin,
6
F. Linde,
37
S. D. Linker,
112
T. B. Littenberg,
148
J. Liu,
63
X. Liu,
23
R. K. L. Lo,
92, 1
N. A. Lockerbie,
24
L. T. London,
68
A. Longo,
149, 150
M. Lorenzini,
14, 15
V. Loriette,
151
M. Lormand,
7
G. Losurdo,
19
J. D. Lough,
8, 9
C. O. Lousto,
58
G. Lovelace,
26
M. E. Lower,
152
H. L
̈
uck,
9, 8
D. Lumaca,
30, 31
A. P. Lundgren,
153
R. Lynch,
12
Y. Ma,
46
R. Macas,
68
S. Macfoy,
24
M. MacInnis,
12
D. M. Macleod,
68
A. Macquet,
65
F. Maga
̃
na-Sandoval,
42
L. Maga
̃
na Zertuche,
85
R. M. Magee,
87
E. Majorana,
32
I. Maksimovic,
151
A. Malik,
61
N. Man,
65
V. Mandic,
43
V. Mangano,
44
G. L. Mansell,
45, 12
M. Manske,
23, 21
M. Mantovani,
28
M. Mapelli,
51, 52, 96, 154
F. Marchesoni,
50, 41
F. Marion,
33
S. M
́
arka,
99
Z. M
́
arka,
99
C. Markakis,
10, 17
A. S. Markosyan,
49
A. Markowitz,
1
E. Maros,
1
A. Marquina,
103
S. Marsat,
36
F. Martelli,
72, 73
I. W. Martin,
44
R. M. Martin,
35
D. V. Martynov,
11
K. Mason,
12
E. Massera,
109
A. Masserot,
33
T. J. Massinger,
1
M. Masso-Reid,
44
S. Mastrogiovanni,
114, 32
A. Matas,
43, 36
F. Matichard,
1, 12
L. Matone,
99
N. Mavalvala,
12
N. Mazumder,
69
J. J. McCann,
63
R. McCarthy,
45
D. E. McClelland,
21
S. McCormick,
7
L. McCuller,
12
S. C. McGuire,
155
J. McIver,
1
D. J. McManus,
21
T. McRae,
21
S. T. McWilliams,
39
D. Meacher,
87
G. D. Meadors,
6
M. Mehmet,
8, 9
A. K. Mehta,
16
J. Meidam,
37
A. Melatos,
98
G. Mendell,
45
R. A. Mercer,
23
L. Mereni,
22
E. L. Merilh,
45
M. Merzougui,
65
S. Meshkov,
1
C. Messenger,
44
C. Messick,
87
R. Metzdorff,
71
P. M. Meyers,
98
H. Miao,
11
C. Michel,
22
H. Middleton,
98
E. E. Mikhailov,
156
L. Milano,
79, 5
A. L. Miller,
48
A. Miller,
114, 32
M. Millhouse,
53
J. C. Mills,
68
M. C. Milovich-Goff,
112
O. Minazzoli,
65, 157
Y. Minenkov,
31
A. Mishkin,
48
C. Mishra,
158
T. Mistry,
109
S. Mitra,
3
V. P. Mitrofanov,
62
G. Mitselmakher,
48
R. Mittleman,
12
G. Mo,
95
D. Moffa,
116
K. Mogushi,
85
S. R. P. Mohapatra,
12
M. Montani,
72, 73
C. J. Moore,
10
D. Moraru,
45
G. Moreno,
45
S. Morisaki,
82
B. Mours,
33
C. M. Mow-Lowry,
11
Arunava Mukherjee,
8, 9
D. Mukherjee,
23
S. Mukherjee,
105
N. Mukund,
3
A. Mullavey,
7
J. Munch,
55
E. A. Mu
̃
niz,
42
M. Muratore,
34
P. G. Murray,
44
A. Nagar,
86, 159, 160
I. Nardecchia,
30, 31
L. Naticchioni,
114, 32
R. K. Nayak,
161
J. Neilson,
112
G. Nelemans,
64, 37
T. J. N. Nelson,
7
M. Nery,
8, 9
A. Neunzert,
126
K. Y. Ng,
12
S. Ng,
55
P. Nguyen,
70
D. Nichols,
128, 37
S. Nissanke,
128, 37
F. Nocera,
28
C. North,
68
L. K. Nuttall,
153
M. Obergaulinger,
20
J. Oberling,
45
B. D. O’Brien,
48
G. D. O’Dea,
112
G. H. Ogin,
162
J. J. Oh,
138
S. H. Oh,
138
F. Ohme,
8, 9
H. Ohta,
82
M. A. Okada,
13
M. Oliver,
100
P. Oppermann,
8, 9
Richard J. Oram,
7
B. O’Reilly,
7
R. G. Ormiston,
43
L. F. Ortega,
48
R. O’Shaughnessy,
58
S. Ossokine,
36
D. J. Ottaway,
55
H. Overmier,
7
B. J. Owen,
84
A. E. Pace,
87
G. Pagano,
18, 19
M. A. Page,
63
A. Pai,
122
S. A. Pai,
61
J. R. Palamos,
70
O. Palashov,
135
C. Palomba,
32
A. Pal-Singh,
140
Huang-Wei Pan,
88
B. Pang,
46
P. T. H. Pang,
92
C. Pankow,
59
F. Pannarale,
114, 32
B. C. Pant,
61
F. Paoletti,
19
A. Paoli,
28
A. Parida,
3
W. Parker,
7, 155
D. Pascucci,
44
A. Pasqualetti,
28
R. Passaquieti,
18, 19
D. Passuello,
19
M. Patil,
143
B. Patricelli,
18, 19
B. L. Pearlstone,
44
C. Pedersen,
68
M. Pedraza,
1
R. Pedurand,
22, 163
A. Pele,
7
S. Penn,
164
C. J. Perez,
45
A. Perreca,
113, 97
H. P. Pfeiffer,
36, 90
M. Phelps,
8, 9
K. S. Phukon,
3
O. J. Piccinni,
114, 32
M. Pichot,
65
F. Piergiovanni,
72, 73
G. Pillant,
28
L. Pinard,
22
M. Pirello,
45
M. Pitkin,
44
R. Poggiani,
18, 19
D. Y. T. Pong,
92
S. Ponrathnam,
3
P. Popolizio,
28
E. K. Porter,
27
J. Powell,
152
A. K. Prajapati,
108
J. Prasad,
3
3
K. Prasai,
49
R. Prasanna,
130
G. Pratten,
100
T. Prestegard,
23
S. Privitera,
36
G. A. Prodi,
113, 97
L. G. Prokhorov,
62
O. Puncken,
8, 9
M. Punturo,
41
P. Puppo,
32
M. P
̈
urrer,
36
H. Qi,
23
V. Quetschke,
105
P. J. Quinonez,
34
E. A. Quintero,
1
R. Quitzow-James,
70
F. J. Raab,
45
H. Radkins,
45
N. Radulescu,
65
P. Raffai,
107
S. Raja,
61
C. Rajan,
61
B. Rajbhandari,
84
M. Rakhmanov,
105
K. E. Ramirez,
105
A. Ramos-Buades,
100
Javed Rana,
3
K. Rao,
59
P. Rapagnani,
114, 32
V. Raymond,
68
M. Razzano,
18, 19
J. Read,
26
T. Regimbau,
33
L. Rei,
60
S. Reid,
24
D. H. Reitze,
1, 48
W. Ren,
17
F. Ricci,
114, 32
C. J. Richardson,
34
J. W. Richardson,
1
P. M. Ricker,
17
K. Riles,
126
M. Rizzo,
59
N. A. Robertson,
1, 44
R. Robie,
44
F. Robinet,
25
A. Rocchi,
31
L. Rolland,
33
J. G. Rollins,
1
V. J. Roma,
70
M. Romanelli,
67
R. Romano,
4, 5
C. L. Romel,
45
J. H. Romie,
7
K. Rose,
116
D. Rosi
́
nska,
165, 54
S. G. Rosofsky,
17
M. P. Ross,
166
S. Rowan,
44
A. R
̈
udiger,
8, 9,
‡
P. Ruggi,
28
G. Rutins,
167
K. Ryan,
45
S. Sachdev,
1
T. Sadecki,
45
M. Sakellariadou,
132
L. Salconi,
28
M. Saleem,
29
A. Samajdar,
37
L. Sammut,
6
E. J. Sanchez,
1
L. E. Sanchez,
1
N. Sanchis-Gual,
20
V. Sandberg,
45
J. R. Sanders,
42
K. A. Santiago,
35
N. Sarin,
6
B. Sassolas,
22
B. S. Sathyaprakash,
87, 68
P. R. Saulson,
42
O. Sauter,
126
R. L. Savage,
45
P. Schale,
70
M. Scheel,
46
J. Scheuer,
59
P. Schmidt,
64
R. Schnabel,
140
R. M. S. Schofield,
70
A. Sch
̈
onbeck,
140
E. Schreiber,
8, 9
B. W. Schulte,
8, 9
B. F. Schutz,
68
S. G. Schwalbe,
34
J. Scott,
44
S. M. Scott,
21
E. Seidel,
17
D. Sellers,
7
A. S. Sengupta,
168
N. Sennett,
36
D. Sentenac,
28
V. Sequino,
30, 31, 14
A. Sergeev,
135
Y. Setyawati,
8, 9
D. A. Shaddock,
21
T. Shaffer,
45
M. S. Shahriar,
59
M. B. Shaner,
112
L. Shao,
36
P. Sharma,
61
P. Shawhan,
76
H. Shen,
17
R. Shink,
169
D. H. Shoemaker,
12
D. M. Shoemaker,
77
S. ShyamSundar,
61
K. Siellez,
77
M. Sieniawska,
54
D. Sigg,
45
A. D. Silva,
13
L. P. Singer,
80
N. Singh,
74
A. Singhal,
14, 32
A. M. Sintes,
100
S. Sitmukhambetov,
105
V. Skliris,
68
B. J. J. Slagmolen,
21
T. J. Slaven-Blair,
63
J. R. Smith,
26
R. J. E. Smith,
6
S. Somala,
170
E. J. Son,
138
B. Sorazu,
44
F. Sorrentino,
60
T. Souradeep,
3
E. Sowell,
84
M. Spera,
59
A. P. Spencer,
44
M. Spera,
51, 52, 96, 154, 59
A. K. Srivastava,
108
V. Srivastava,
42
K. Staats,
59
C. Stachie,
65
M. Standke,
8, 9
D. A. Steer,
27
M. Steinke,
8, 9
J. Steinlechner,
140, 44
S. Steinlechner,
140
D. Steinmeyer,
8, 9
S. P. Stevenson,
152
D. Stocks,
49
R. Stone,
105
D. J. Stops,
11
K. A. Strain,
44
G. Stratta,
72, 73
S. E. Strigin,
62
A. Strunk,
45
R. Sturani,
171
A. L. Stuver,
172
V. Sudhir,
12
T. Z. Summerscales,
173
L. Sun,
1
S. Sunil,
108
J. Suresh,
3
P. J. Sutton,
68
B. L. Swinkels,
37
M. J. Szczepa
́
nczyk,
34
M. Tacca,
37
S. C. Tait,
44
C. Talbot,
6
D. Talukder,
70
D. B. Tanner,
48
M. T
́
apai,
123
A. Taracchini,
36
J. D. Tasson,
95
R. Taylor,
1
F. Thies,
8, 9
M. Thomas,
7
P. Thomas,
45
S. R. Thondapu,
61
K. A. Thorne,
7
E. Thrane,
6
Shubhanshu Tiwari,
113, 97
Srishti Tiwari,
124
V. Tiwari,
68
K. Toland,
44
M. Tonelli,
18, 19
Z. Tornasi,
44
A. Torres-Forn
́
e,
174
C. I. Torrie,
1
D. T
̈
oyr
̈
a,
11
F. Travasso,
28, 41
G. Traylor,
7
M. C. Tringali,
74
A. Trovato,
27
L. Trozzo,
175, 19
R. Trudeau,
1
K. W. Tsang,
37
M. Tse,
12
R. Tso,
46
L. Tsukada,
82
D. Tsuna,
82
D. Tuyenbayev,
105
K. Ueno,
82
D. Ugolini,
176
C. S. Unnikrishnan,
124
A. L. Urban,
2
S. A. Usman,
68
H. Vahlbruch,
9
G. Vajente,
1
G. Valdes,
2
N. van Bakel,
37
M. van Beuzekom,
37
J. F. J. van den Brand,
75, 37
C. Van Den Broeck,
37, 177
D. C. Vander-Hyde,
42
L. van der Schaaf,
37
J. V. van Heijningen,
63
A. A. van Veggel,
44
M. Vardaro,
51, 52
V. Varma,
46
S. Vass,
1
M. Vas
́
uth,
47
A. Vecchio,
11
G. Vedovato,
52
J. Veitch,
44
P. J. Veitch,
55
K. Venkateswara,
166
G. Venugopalan,
1
D. Verkindt,
33
F. Vetrano,
72, 73
A. Vicer
́
e,
72, 73
A. D. Viets,
23
D. J. Vine,
167
J.-Y. Vinet,
65
S. Vitale,
12
T. Vo,
42
H. Vocca,
40, 41
C. Vorvick,
45
S. P. Vyatchanin,
62
A. R. Wade,
1
L. E. Wade,
116
M. Wade,
116
R. Walet,
37
M. Walker,
26
L. Wallace,
1
S. Walsh,
23
G. Wang,
14, 19
H. Wang,
11
J. Z. Wang,
126
W. H. Wang,
105
Y. F. Wang,
92
R. L. Ward,
21
Z. A. Warden,
34
J. Warner,
45
M. Was,
33
J. Watchi,
101
B. Weaver,
45
L.-W. Wei,
8, 9
M. Weinert,
8, 9
A. J. Weinstein,
1
R. Weiss,
12
F. Wellmann,
8, 9
L. Wen,
63
E. K. Wessel,
17
P. Weßels,
8, 9
J. W. Westhouse,
34
K. Wette,
21
J. T. Whelan,
58
B. F. Whiting,
48
C. Whittle,
12
D. M. Wilken,
8, 9
D. Williams,
44
A. R. Williamson,
128, 37
J. L. Willis,
1
B. Willke,
8, 9
M. H. Wimmer,
8, 9
W. Winkler,
8, 9
C. C. Wipf,
1
H. Wittel,
8, 9
G. Woan,
44
J. Woehler,
8, 9
J. K. Wofford,
58
J. Worden,
45
J. L. Wright,
44
D. S. Wu,
8, 9
D. M. Wysocki,
58
L. Xiao,
1
H. Yamamoto,
1
C. C. Yancey,
76
L. Yang,
115
M. J. Yap,
21
M. Yazback,
48
D. W. Yeeles,
68
Hang Yu,
12
Haocun Yu,
12
S. H. R. Yuen,
92
M. Yvert,
33
A. K. Zadro
̇
zny,
105, 142
M. Zanolin,
34
T. Zelenova,
28
J.-P. Zendri,
52
M. Zevin,
59
J. Zhang,
63
L. Zhang,
1
T. Zhang,
44
C. Zhao,
63
M. Zhou,
59
Z. Zhou,
59
X. J. Zhu,
6
A. B. Zimmerman,
90
Y. Zlochower,
58
M. E. Zucker,
1, 12
and J. Zweizig
1
The LIGO Scientific Collaboration and the Virgo Collaboration
1
LIGO, California Institute of Technology, Pasadena, CA 91125, USA
2
Louisiana State University, Baton Rouge, LA 70803, USA
3
Inter-University Centre for Astronomy and Astrophysics, Pune 411007, India
4
Universit`a di Salerno, Fisciano, I-84084 Salerno, Italy
5
INFN, Sezione di Napoli, Complesso Universitario di Monte S.Angelo, I-80126 Napoli, Italy
6
OzGrav, School of Physics & Astronomy, Monash University, Clayton 3800, Victoria, Australia
7
LIGO Livingston Observatory, Livingston, LA 70754, USA
8
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), D-30167 Hannover, Germany
9
Leibniz Universit ̈at Hannover, D-30167 Hannover, Germany
10
University of Cambridge, Cambridge CB2 1TN, United Kingdom
11
University of Birmingham, Birmingham B15 2TT, United Kingdom
12
LIGO, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
13
Instituto Nacional de Pesquisas Espaciais, 12227-010 S ̃ao Jos ́e dos Campos, S ̃ao Paulo, Brazil
14
Gran Sasso Science Institute (GSSI), I-67100 L’Aquila, Italy
4
15
INFN, Laboratori Nazionali del Gran Sasso, I-67100 Assergi, Italy
16
International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru 560089, India
17
NCSA, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
18
Universit`a di Pisa, I-56127 Pisa, Italy
19
INFN, Sezione di Pisa, I-56127 Pisa, Italy
20
Departamento de Astronom ́ıa y Astrof ́ısica, Universitat de Val`encia, E-46100 Burjassot, Val`encia, Spain
21
OzGrav, Australian National University, Canberra, Australian Capital Territory 0200, Australia
22
Laboratoire des Mat ́eriaux Avanc ́es (LMA), CNRS/IN2P3, F-69622 Villeurbanne, France
23
University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
24
SUPA, University of Strathclyde, Glasgow G1 1XQ, United Kingdom
25
LAL, Univ. Paris-Sud, CNRS/IN2P3, Universit ́e Paris-Saclay, F-91898 Orsay, France
26
California State University Fullerton, Fullerton, CA 92831, USA
27
APC, AstroParticule et Cosmologie, Universit ́e Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cit ́e,
F-75205 Paris Cedex 13, France
28
European Gravitational Observatory (EGO), I-56021 Cascina, Pisa, Italy
29
Chennai Mathematical Institute, Chennai 603103, India
30
Universit`a di Roma Tor Vergata, I-00133 Roma, Italy
31
INFN, Sezione di Roma Tor Vergata, I-00133 Roma, Italy
32
INFN, Sezione di Roma, I-00185 Roma, Italy
33
Laboratoire d’Annecy de Physique des Particules (LAPP), Univ. Grenoble Alpes, Universit ́e Savoie Mont Blanc, CNRS/IN2P3,
F-74941 Annecy, France
34
Embry-Riddle Aeronautical University, Prescott, AZ 86301, USA
35
Montclair State University, Montclair, NJ 07043, USA
36
Max Planck Institute for Gravitational Physics (Albert Einstein Institute), D-14476 Potsdam-Golm, Germany
37
Nikhef, Science Park 105, 1098 XG Amsterdam, The Netherlands
38
Korea Institute of Science and Technology Information, Daejeon 34141, South Korea
39
West Virginia University, Morgantown, WV 26506, USA
40
Universit`a di Perugia, I-06123 Perugia, Italy
41
INFN, Sezione di Perugia, I-06123 Perugia, Italy
42
Syracuse University, Syracuse, NY 13244, USA
43
University of Minnesota, Minneapolis, MN 55455, USA
44
SUPA, University of Glasgow, Glasgow G12 8QQ, United Kingdom
45
LIGO Hanford Observatory, Richland, WA 99352, USA
46
Caltech CaRT, Pasadena, CA 91125, USA
47
Wigner RCP, RMKI, H-1121 Budapest, Konkoly Thege Mikl ́os ́ut 29-33, Hungary
48
University of Florida, Gainesville, FL 32611, USA
49
Stanford University, Stanford, CA 94305, USA
50
Universit`a di Camerino, Dipartimento di Fisica, I-62032 Camerino, Italy
51
Universit`a di Padova, Dipartimento di Fisica e Astronomia, I-35131 Padova, Italy
52
INFN, Sezione di Padova, I-35131 Padova, Italy
53
Montana State University, Bozeman, MT 59717, USA
54
Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, 00-716, Warsaw, Poland
55
OzGrav, University of Adelaide, Adelaide, South Australia 5005, Australia
56
Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universit ̈at Jena, D-07743 Jena, Germany
57
INFN, Sezione di Milano Bicocca, Gruppo Collegato di Parma, I-43124 Parma, Italy
58
Rochester Institute of Technology, Rochester, NY 14623, USA
59
Center for Interdisciplinary Exploration & Research in Astrophysics (CIERA), Northwestern University, Evanston, IL 60208, USA
60
INFN, Sezione di Genova, I-16146 Genova, Italy
61
RRCAT, Indore, Madhya Pradesh 452013, India
62
Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
63
OzGrav, University of Western Australia, Crawley, Western Australia 6009, Australia
64
Department of Astrophysics/IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands
65
Artemis, Universit ́e Cˆote d’Azur, Observatoire Cˆote d’Azur, CNRS, CS 34229, F-06304 Nice Cedex 4, France
66
Physik-Institut, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
67
Univ Rennes, CNRS, Institut FOTON - UMR6082, F-3500 Rennes, France
68
Cardiff University, Cardiff CF24 3AA, United Kingdom
69
Washington State University, Pullman, WA 99164, USA
5
70
University of Oregon, Eugene, OR 97403, USA
71
Laboratoire Kastler Brossel, Sorbonne Universit ́e, CNRS, ENS-Universit ́e PSL, Coll`ege de France, F-75005 Paris, France
72
Universit`a degli Studi di Urbino ’Carlo Bo,’ I-61029 Urbino, Italy
73
INFN, Sezione di Firenze, I-50019 Sesto Fiorentino, Firenze, Italy
74
Astronomical Observatory Warsaw University, 00-478 Warsaw, Poland
75
VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
76
University of Maryland, College Park, MD 20742, USA
77
School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA
78
Universit ́e Claude Bernard Lyon 1, F-69622 Villeurbanne, France
79
Universit`a di Napoli ’Federico II,’ Complesso Universitario di Monte S.Angelo, I-80126 Napoli, Italy
80
NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
81
Dipartimento di Fisica, Universit`a degli Studi di Genova, I-16146 Genova, Italy
82
RESCEU, University of Tokyo, Tokyo, 113-0033, Japan.
83
Tsinghua University, Beijing 100084, China
84
Texas Tech University, Lubbock, TX 79409, USA
85
The University of Mississippi, University, MS 38677, USA
86
Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, I-00184 Roma, Italyrico Fermi, I-00184 Roma, Italy
87
The Pennsylvania State University, University Park, PA 16802, USA
88
National Tsing Hua University, Hsinchu City, 30013 Taiwan, Republic of China
89
Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia
90
Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, Ontario M5S 3H8, Canada
91
University of Chicago, Chicago, IL 60637, USA
92
The Chinese University of Hong Kong, Shatin, NT, Hong Kong
93
Seoul National University, Seoul 08826, South Korea
94
Pusan National University, Busan 46241, South Korea
95
Carleton College, Northfield, MN 55057, USA
96
INAF, Osservatorio Astronomico di Padova, I-35122 Padova, Italy
97
INFN, Trento Institute for Fundamental Physics and Applications, I-38123 Povo, Trento, Italy
98
OzGrav, University of Melbourne, Parkville, Victoria 3010, Australia
99
Columbia University, New York, NY 10027, USA
100
Universitat de les Illes Balears, IAC3—IEEC, E-07122 Palma de Mallorca, Spain
101
Universit ́e Libre de Bruxelles, Brussels 1050, Belgium
102
Sonoma State University, Rohnert Park, CA 94928, USA
103
Departamento de Matem ́aticas, Universitat de Val`encia, E-46100 Burjassot, Val`encia, Spain
104
University of Rhode Island, Kingston, RI 02881, USA
105
The University of Texas Rio Grande Valley, Brownsville, TX 78520, USA
106
Bellevue College, Bellevue, WA 98007, USA
107
MTA-ELTE Astrophysics Research Group, Institute of Physics, E ̈otv ̈os University, Budapest 1117, Hungary
108
Institute for Plasma Research, Bhat, Gandhinagar 382428, India
109
The University of Sheffield, Sheffield S10 2TN, United Kingdom
110
IGFAE, Campus Sur, Universidade de Santiago de Compostela, 15782 Spain
111
Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Universit`a di Parma, I-43124 Parma, Italy
112
California State University, Los Angeles, 5151 State University Dr, Los Angeles, CA 90032, USA
113
Universit`a di Trento, Dipartimento di Fisica, I-38123 Povo, Trento, Italy
114
Universit`a di Roma ’La Sapienza,’ I-00185 Roma, Italy
115
Colorado State University, Fort Collins, CO 80523, USA
116
Kenyon College, Gambier, OH 43022, USA
117
Christopher Newport University, Newport News, VA 23606, USA
118
National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
119
Observatori Astron`omic, Universitat de Val`encia, E-46980 Paterna, Val`encia, Spain
120
School of Mathematics, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
121
Institute Of Advanced Research, Gandhinagar 382426, India
122
Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
123
University of Szeged, D ́om t ́er 9, Szeged 6720, Hungary
124
Tata Institute of Fundamental Research, Mumbai 400005, India
125
INAF, Osservatorio Astronomico di Capodimonte, I-80131, Napoli, Italy
126
University of Michigan, Ann Arbor, MI 48109, USA
6
127
American University, Washington, D.C. 20016, USA
128
GRAPPA, Anton Pannekoek Institute for Astronomy and Institute of High-Energy Physics, University of Amsterdam, Science Park
904, 1098 XH Amsterdam, The Netherlands
129
Delta Institute for Theoretical Physics, Science Park 904, 1090 GL Amsterdam, The Netherlands
130
Directorate of Construction, Services & Estate Management, Mumbai 400094 India
131
University of Bia lystok, 15-424 Bia lystok, Poland
132
King’s College London, University of London, London WC2R 2LS, United Kingdom
133
University of Southampton, Southampton SO17 1BJ, United Kingdom
134
University of Washington Bothell, Bothell, WA 98011, USA
135
Institute of Applied Physics, Nizhny Novgorod, 603950, Russia
136
Ewha Womans University, Seoul 03760, South Korea
137
Inje University Gimhae, South Gyeongsang 50834, South Korea
138
National Institute for Mathematical Sciences, Daejeon 34047, South Korea
139
Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
140
Universit ̈at Hamburg, D-22761 Hamburg, Germany
141
Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
142
NCBJ, 05-400
́
Swierk-Otwock, Poland
143
Institute of Mathematics, Polish Academy of Sciences, 00656 Warsaw, Poland
144
Cornell University, Ithaca, NY 14850, USA
145
Hillsdale College, Hillsdale, MI 49242, USA
146
Hanyang University, Seoul 04763, South Korea
147
Korea Astronomy and Space Science Institute, Daejeon 34055, South Korea
148
NASA Marshall Space Flight Center, Huntsville, AL 35811, USA
149
Dipartimento di Matematica e Fisica, Universit`a degli Studi Roma Tre, I-00146 Roma, Italy
150
INFN, Sezione di Roma Tre, I-00146 Roma, Italy
151
ESPCI, CNRS, F-75005 Paris, France
152
OzGrav, Swinburne University of Technology, Hawthorn VIC 3122, Australia
153
University of Portsmouth, Portsmouth, PO1 3FX, United Kingdom
154
Institut f ̈ur Astro- und Teilchenphysik, Universit ̈at Innsbruck, Technikerstrasse 25/8, A-6020, Innsbruck, Austria
155
Southern University and A&M College, Baton Rouge, LA 70813, USA
156
College of William and Mary, Williamsburg, VA 23187, USA
157
Centre Scientifique de Monaco, 8 quai Antoine Ier, MC-98000, Monaco
158
Indian Institute of Technology Madras, Chennai 600036, India
159
INFN Sezione di Torino, Via P. Giuria 1, I-10125 Torino, Italy
160
Institut des Hautes Etudes Scientifiques, F-91440 Bures-sur-Yvette, France
161
IISER-Kolkata, Mohanpur, West Bengal 741252, India
162
Whitman College, 345 Boyer Avenue, Walla Walla, WA 99362 USA
163
Universit ́e de Lyon, F-69361 Lyon, France
164
Hobart and William Smith Colleges, Geneva, NY 14456, USA
165
Janusz Gil Institute of Astronomy, University of Zielona G ́ora, 65-265 Zielona G ́ora, Poland
166
University of Washington, Seattle, WA 98195, USA
167
SUPA, University of the West of Scotland, Paisley PA1 2BE, United Kingdom
168
Indian Institute of Technology, Gandhinagar Ahmedabad Gujarat 382424, India
169
Universit ́e de Montr ́eal/Polytechnique, Montreal, Quebec H3T 1J4, Canada
170
Indian Institute of Technology Hyderabad, Sangareddy, Khandi, Telangana 502285, India
171
International Institute of Physics, Universidade Federal do Rio Grande do Norte, Natal RN 59078-970, Brazil
172
Villanova University, 800 Lancaster Ave, Villanova, PA 19085, USA
173
Andrews University, Berrien Springs, MI 49104, USA
174
Max Planck Institute for Gravitationalphysik (Albert Einstein Institute), D-14476 Potsdam-Golm, Germany
175
Universit`a di Siena, I-53100 Siena, Italy
176
Trinity University, San Antonio, TX 78212, USA
177
Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The
Netherlands
ABSTRACT
7
We present results on the mass, spin, and redshift distributions of the ten binary black hole mergers
detected in the first and second observing runs completed by Advanced LIGO and Advanced Virgo.
We constrain properties of the binary black hole (BBH) mass spectrum using models with a range of
parameterizations of the BBH mass and spin distributions. We find that the mass distribution of the
more massive black hole in such binaries is well approximated by models with no more than 1% of
black holes more massive than 45
M
, and a power law index of
α
= 1
.
6
+1
.
5
−
1
.
7
(90% credibility). We
also show that BBHs are unlikely to be composed of black holes with large spins aligned to the orbital
angular momentum. Modelling the evolution of the BBH merger rate with redshift, we show that it
is flat or increasing with redshift with 88% probability. Marginalizing over uncertainties in the BBH
population, we find robust estimates of the BBH merger rate density of
R
= 53
.
2
+58
.
5
−
28
.
8
Gpc
−
3
yr
−
1
(90%
credibility). As the BBH catalog grows in future observing runs, we expect that uncertainties in the
population model parameters will shrink, potentially providing insights into the formation of black
holes via supernovae, binary interactions of massive stars, stellar cluster dynamics, and the formation
history of black holes across cosmic time.
1.
INTRODUCTION
The second LIGO/Virgo observing run (O2) spanned
nine months between November 2016 through August
2017, building upon the first, four-month run (O1) in
2015. The LIGO/Virgo gravitational-wave (GW) inter-
ferometer network is comprised of two instruments in
the United States (LIGO) (LIGO Scientific Collabora-
tion et al. 2015; Abbott et al. 2016d) and a third in
Europe (Virgo) (Acernese et al. 2015), the latter join-
ing the run in the summer of 2017. In total, ten bi-
nary black hole (BBH) mergers have been detected to
date (Abbott et al. 2018). The BBHs detected possess a
wide range of physical properties. The lightest so far is
GW170608 (Abbott et al. 2017d) with an inferred total
mass of 18
.
7
+3
.
3
−
0
.
7
M
. GW170729 (Abbott et al. 2018)—
exceptional in several ways—is likely to be the heaviest
BBH to date, having total mass 85
.
2
+15
.
4
−
11
.
2
M
, as well as
the most distant, at redshift 0
.
48
+0
.
19
−
0
.
20
. Both GW151226
and GW170729 show evidence for at least one black hole
with a spin greater than zero (Abbott et al. 2016e; Ab-
bott et al. 2018).
By measuring the distributions of mass, spin, and
merger redshift in the BBH population, we may make
inferences about the physics of binary mergers and bet-
ter understand the origin of these systems. We employ
Bayesian inference and modelling (Gelman et al. 2004;
Mandel 2010; Foreman-Mackey et al. 2014) which, when
applied to parameterized models of the population, is
able to infer population-level parameters — sometimes
called hyperparameters to distinguish them from the
event-level parameters — while properly accounting for
the uncertainty in the measurements of each event’s pa-
rameters (Mandel 2010; Hogg et al. 2010).
∗
Deceased, February 2018.
†
Deceased, November 2017.
‡
Deceased, July 2018.
The structure and parameterization of BBH popula-
tions models are guided by the physical processes and
evolutionary environments in which BBH are expected
to form and merge. Several BBH formation channels
have been proposed in the literature, each of them in-
volving a specific environment and a number of physical
processes. For example, BBHs might form from isolated
massive binaries in the galactic field through common-
envelope evolution (Bethe & Brown 1998; Portegies
Zwart & Yungelson 1998; Belczynski et al. 2002; Voss
& Tauris 2003; Dewi et al. 2006; Belczynski et al. 2007,
2008; Dominik et al. 2013; Belczynski et al. 2014; Men-
nekens & Vanbeveren 2014; Spera et al. 2015; Tauris
et al. 2017; Eldridge & Stanway 2016; Stevenson et al.
2017b; Chruslinska et al. 2018; Mapelli et al. 2017; Gi-
acobbo et al. 2018; Mapelli & Giacobbo 2018; Kruckow
et al. 2018; Giacobbo & Mapelli 2018) or via chemically
homogeneous evolution (Marchant et al. 2016; de Mink
& Mandel 2016; Mandel & de Mink 2016). Alterna-
tively, BBHs might form via dynamical processes in stel-
lar clusters (Portegies Zwart & McMillan 2000; Kulka-
rni et al. 1993; Sigurdsson & Hernquist 1993; Grind-
lay et al. 2006; O’Leary et al. 2006; Sadowski et al.
2008; Ivanova et al. 2008; Downing et al. 2010, 2011;
Clausen et al. 2013; Ziosi et al. 2014; Rodriguez et al.
2015, 2016a; Mapelli 2016; Askar et al. 2017; Banerjee
2017; Chatterjee et al. 2017) and galactic nuclei (An-
tonini & Perets 2012; Antonini & Rasio 2016; Petrovich
& Antonini 2017), evolution of hierarchical triple sys-
tems (Antonini et al. 2014; Kimpson et al. 2016; An-
tonini et al. 2017; Liu & Lai 2018), gas drag and stellar
scattering in accretion disks surrounding super-massive
black holes (McKernan et al. 2012; Bartos et al. 2017;
Stone et al. 2017). Finally, BBHs might originate as
part of a primordial black hole population in the early
Universe (Carr & Hawking 1974; Carr et al. 2016; Sasaki
et al. 2016; Inomata et al. 2017; Inayoshi et al. 2016; Bird
et al. 2016; Ali-Ha ̈ımoud et al. 2017; Clesse & Garc ́ıa-