Draft version January 8, 2019
Typeset using L
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SEARCHES FOR CONTINUOUS GRAVITATIONAL WAVES FROM FIFTEEN SUPERNOVA REMNANTS
AND FOMALHAUT B WITH ADVANCED LIGO
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
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
K. C. Cannon,
81
H. Cao,
55
J. Cao,
82
E. Capocasa,
27
F. Carbognani,
28
S. Caride,
83
M. F. Carney,
59
G. Carullo,
18
J. Casanueva Diaz,
19
C. Casentini,
30, 31
S. Caudill,
37
M. Cavagli
`
a,
84
F. Cavalier,
25
R. Cavalieri,
28
G. Cella,
19
P. Cerd
́
a-Dur
́
an,
20
G. Cerretani,
18, 19
E. Cesarini,
85, 31
O. Chaibi,
65
K. Chakravarti,
3
S. J. Chamberlin,
86
M. Chan,
44
S. Chao,
87
P. Charlton,
88
E. A. Chase,
59
E. Chassande-Mottin,
27
D. Chatterjee,
23
M. Chaturvedi,
61
B. D. Cheeseboro,
39
H. Y. Chen,
89
X. Chen,
63
Y. Chen,
46
H.-P. Cheng,
48
C. K. Cheong,
90
H. Y. Chia,
48
A. Chincarini,
60
A. Chiummo,
28
G. Cho,
91
H. S. Cho,
92
M. Cho,
76
N. Christensen,
65, 93
Q. Chu,
63
S. Chua,
71
K. W. Chung,
90
S. Chung,
63
G. Ciani,
51, 52
A. A. Ciobanu,
55
R. Ciolfi,
94, 95
F. Cipriano,
65
A. Cirone,
96, 60
F. Clara,
45
J. A. Clark,
77
P. Clearwater,
97
F. Cleva,
65
C. Cocchieri,
84
E. Coccia,
14, 15
P.-F. Cohadon,
71
D. Cohen,
25
R. Colgan,
98
M. Colleoni,
99
C. G. Collette,
100
C. Collins,
11
L. R. Cominsky,
101
M. Constancio Jr.,
13
L. Conti,
52
S. J. Cooper,
11
P. Corban,
7
T. R. Corbitt,
2
I. Cordero-Carri
́
on,
102
K. R. Corley,
98
N. Cornish,
53
A. Corsi,
83
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,
98
P. Couvares,
1
P. B. Covas,
99
E. E. Cowan,
77
D. M. Coward,
63
M. J. Cowart,
7
D. C. Coyne,
1
R. Coyne,
103
J. D. E. Creighton,
23
T. D. Creighton,
104
J. Cripe,
2
M. Croquette,
71
S. G. Crowder,
105
T. J. Cullen,
2
A. Cumming,
44
L. Cunningham,
44
E. Cuoco,
28
T. Dal Canton,
80
G. D
́
alya,
106
S. L. Danilishin,
8, 9
S. D’Antonio,
31
K. Danzmann,
9, 8
A. Dasgupta,
107
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,
108
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
M. Denys,
74
R. De Pietri,
109, 57
J. Derby,
26
R. De Rosa,
79, 5
C. De Rossi,
22, 28
R. DeSalvo,
110
O. de Varona,
8, 9
S. Dhurandhar,
3
M. C. D
́
ıaz,
104
T. Dietrich,
37
L. Di Fiore,
5
M. Di Giovanni,
111, 95
T. Di Girolamo,
79, 5
A. Di Lieto,
18, 19
B. Ding,
100
S. Di Pace,
112, 32
I. Di Palma,
112, 32
F. Di Renzo,
18, 19
A. Dmitriev,
11
Z. Doctor,
89
F. Donovan,
12
K. L. Dooley,
68, 84
S. Doravari,
8, 9
I. Dorrington,
68
T. P. Downes,
23
M. Drago,
14, 15
J. C. Driggers,
45
Z. Du,
82
J.-G. Ducoin,
25
P. Dupej,
44
S. E. Dwyer,
45
P. J. Easter,
6
T. B. Edo,
108
M. C. Edwards,
93
A. Effler,
7
P. Ehrens,
1
J. Eichholz,
1
S. S. Eikenberry,
48
M. Eisenmann,
33
R. A. Eisenstein,
12
R. C. Essick,
89
H. Estelles,
99
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,
82
S. Farinon,
60
B. Farr,
70
W. M. Farr,
11
E. J. Fauchon-Jones,
68
M. Favata,
35
M. Fays,
108
M. Fazio,
113
C. Fee,
114
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,
89
R. P. Fisher,
42, 115
J. M. Fishner,
12
M. Fitz-Axen,
43
R. Flaminio,
33, 116
M. Fletcher,
44
E. Flynn,
26
H. Fong,
117
J. A. Font,
20, 118
P. W. F. Forsyth,
21
J.-D. Fournier,
65
S. Frasca,
112, 32
F. Frasconi,
19
Z. Frei,
106
A. Freise,
11
R. Frey,
70
V. Frey,
25
P. Fritschel,
12
V. V. Frolov,
7
arXiv:1812.11656v2 [astro-ph.HE] 4 Jan 2019
2
P. Fulda,
48
M. Fyffe,
7
H. A. Gabbard,
44
B. U. Gadre,
3
S. M. Gaebel,
11
J. R. Gair,
119
L. Gammaitoni,
40
M. R. Ganija,
55
S. G. Gaonkar,
3
A. Garcia,
26
C. Garc
́
ıa-Quir
́
os,
99
F. Garufi,
79, 5
B. Gateley,
45
S. Gaudio,
34
G. Gaur,
120
V. Gayathri,
121
G. Gemme,
60
E. Genin,
28
A. Gennai,
19
D. George,
17
J. George,
61
L. Gergely,
122
V. Germain,
33
S. Ghonge,
77
Abhirup Ghosh,
16
Archisman Ghosh,
37
S. Ghosh,
23
B. Giacomazzo,
111, 95
J. A. Giaime,
2, 7
K. D. Giardina,
7
A. Giazotto,
19,
†
K. Gill,
34
G. Giordano,
4, 5
L. Glover,
110
P. Godwin,
86
E. Goetz,
45
R. Goetz,
48
B. Goncharov,
6
G. Gonz
́
alez,
2
J. M. Gonzalez Castro,
18, 19
A. Gopakumar,
123
M. L. Gorodetsky,
62
S. E. Gossan,
1
M. Gosselin,
28
R. Gouaty,
33
A. Grado,
124, 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,
107
Y. Guo,
37
A. Gupta,
86
M. K. Gupta,
107
E. K. Gustafson,
1
R. Gustafson,
125
L. Haegel,
99
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,
86
O. A. Hannuksela,
90
J. Hanson,
7
T. Hardwick,
2
K. Haris,
16
J. Harms,
14, 15
G. M. Harry,
126
I. W. Harry,
36
C.-J. Haster,
117
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
F. J. Hernandez,
6
M. Heurs,
8, 9
S. Hild,
44
T. Hinderer,
127, 37, 128
D. Hoak,
28
S. Hochheim,
8, 9
D. Hofman,
22
A. M. Holgado,
17
N. A. Holland,
21
K. Holt,
7
D. E. Holz,
89
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,
99
S. H. Huttner,
44
T. Huynh-Dinh,
7
B. Idzkowski,
74
A. Iess,
30, 31
C. Ingram,
55
R. Inta,
83
G. Intini,
112, 32
B. Irwin,
114
H. N. Isa,
44
J.-M. Isac,
71
M. Isi,
1
B. R. Iyer,
16
K. Izumi,
45
T. Jacqmin,
71
S. J. Jadhav,
129
K. Jani,
77
N. N. Janthalur,
129
P. Jaranowski,
130
A. C. Jenkins,
131
J. Jiang,
48
D. S. Johnson,
17
A. W. Jones,
11
D. I. Jones,
132
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,
84
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,
108
J. S. Key,
133
F. Y. Khalili,
62
H. Khan,
26
I. Khan,
14, 31
S. Khan,
8, 9
Z. Khan,
107
E. A. Khazanov,
134
M. Khursheed,
61
N. Kijbunchoo,
21
Chunglee Kim,
135
J. C. Kim,
136
K. Kim,
90
W. Kim,
55
W. S. Kim,
137
Y.-M. Kim,
138
C. Kimball,
59
E. J. King,
55
P. J. King,
45
M. Kinley-Hanlon,
126
R. Kirchhoff,
8, 9
J. S. Kissel,
45
L. Kleybolte,
139
J. H. Klika,
23
S. Klimenko,
48
T. D. Knowles,
39
P. Koch,
8, 9
S. M. Koehlenbeck,
8, 9
G. Koekoek,
37, 140
S. Koley,
37
V. Kondrashov,
1
A. Kontos,
12
N. Koper,
8, 9
M. Korobko,
139
W. Z. Korth,
1
I. Kowalska,
74
D. B. Kozak,
1
V. Kringel,
8, 9
N. Krishnendu,
29
A. Kr
́
olak,
141, 142
G. Kuehn,
8, 9
A. Kumar,
129
P. Kumar,
143
R. Kumar,
107
S. Kumar,
16
L. Kuo,
87
A. Kutynia,
141
S. Kwang,
23
B. D. Lackey,
36
K. H. Lai,
90
T. L. Lam,
90
M. Landry,
45
B. B. Lane,
12
R. N. Lang,
144
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,
112, 32
S. Leavey,
8, 9
Y. K. Lecoeuche,
45
C. H. Lee,
92
H. K. Lee,
145
H. M. Lee,
146
H. W. Lee,
136
J. Lee,
91
K. Lee,
44
J. Lehmann,
8, 9
A. Lenon,
39
N. Leroy,
25
N. Letendre,
33
Y. Levin,
6, 98
J. Li,
82
K. J. L. Li,
90
T. G. F. Li,
90
X. Li,
46
F. Lin,
6
F. Linde,
37
S. D. Linker,
110
T. B. Littenberg,
147
J. Liu,
63
X. Liu,
23
R. K. L. Lo,
90, 1
N. A. Lockerbie,
24
L. T. London,
68
A. Longo,
148, 149
M. Lorenzini,
14, 15
V. Loriette,
150
M. Lormand,
7
G. Losurdo,
19
J. D. Lough,
8, 9
C. O. Lousto,
58
G. Lovelace,
26
M. E. Lower,
151
H. L
̈
uck,
9, 8
D. Lumaca,
30, 31
A. P. Lundgren,
152
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,
84
R. M. Magee,
86
E. Majorana,
32
I. Maksimovic,
150
A. Malik,
61
N. Man,
65
V. Mandic,
43
V. Mangano,
44
G. L. Mansell,
45, 12
M. Manske,
23, 21
M. Mantovani,
28
F. Marchesoni,
50, 41
F. Marion,
33
S. M
́
arka,
98
Z. M
́
arka,
98
C. Markakis,
10, 17
A. S. Markosyan,
49
A. Markowitz,
1
E. Maros,
1
A. Marquina,
102
S. Marsat,
36
F. Martelli,
72, 73
I. W. Martin,
44
R. M. Martin,
35
D. V. Martynov,
11
K. Mason,
12
E. Massera,
108
A. Masserot,
33
T. J. Massinger,
1
M. Masso-Reid,
44
S. Mastrogiovanni,
112, 32
A. Matas,
43, 36
F. Matichard,
1, 12
L. Matone,
98
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,
153
J. McIver,
1
D. J. McManus,
21
T. McRae,
21
S. T. McWilliams,
39
D. Meacher,
86
G. D. Meadors,
6
M. Mehmet,
8, 9
A. K. Mehta,
16
J. Meidam,
37
A. Melatos,
97
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,
86
R. Metzdorff,
71
P. M. Meyers,
97
H. Miao,
11
C. Michel,
22
H. Middleton,
97
E. E. Mikhailov,
154
L. Milano,
79, 5
A. L. Miller,
48
A. Miller,
112, 32
M. Millhouse,
53
J. C. Mills,
68
M. C. Milovich-Goff,
110
O. Minazzoli,
65, 155
Y. Minenkov,
31
A. Mishkin,
48
C. Mishra,
156
T. Mistry,
108
S. Mitra,
3
V. P. Mitrofanov,
62
G. Mitselmakher,
48
R. Mittleman,
12
G. Mo,
93
D. Moffa,
114
K. Mogushi,
84
S. R. P. Mohapatra,
12
M. Montani,
72, 73
C. J. Moore,
10
D. Moraru,
45
G. Moreno,
45
S. Morisaki,
81
B. Mours,
33
C. M. Mow-Lowry,
11
Arunava Mukherjee,
8, 9
D. Mukherjee,
23
S. Mukherjee,
104
N. Mukund,
3
A. Mullavey,
7
J. Munch,
55
E. A. Mu
̃
niz,
42
M. Muratore,
34
P. G. Murray,
44
A. Nagar,
85, 157, 158
I. Nardecchia,
30, 31
L. Naticchioni,
112, 32
R. K. Nayak,
159
J. Neilson,
110
G. Nelemans,
64, 37
T. J. N. Nelson,
7
M. Nery,
8, 9
A. Neunzert,
125
K. Y. Ng,
12
S. Ng,
55
P. Nguyen,
70
D. Nichols,
127, 37
S. Nissanke,
127, 37
F. Nocera,
28
C. North,
68
L. K. Nuttall,
152
M. Obergaulinger,
20
J. Oberling,
45
B. D. O’Brien,
48
G. D. O’Dea,
110
G. H. Ogin,
160
J. J. Oh,
137
S. H. Oh,
137
F. Ohme,
8, 9
H. Ohta,
81
M. A. Okada,
13
M. Oliver,
99
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,
83
A. E. Pace,
86
G. Pagano,
18, 19
M. A. Page,
63
A. Pai,
121
S. A. Pai,
61
J. R. Palamos,
70
O. Palashov,
134
3
C. Palomba,
32
A. Pal-Singh,
139
Huang-Wei Pan,
87
B. Pang,
46
P. T. H. Pang,
90
C. Pankow,
59
F. Pannarale,
112, 32
B. C. Pant,
61
F. Paoletti,
19
A. Paoli,
28
A. Parida,
3
W. Parker,
7, 153
D. Pascucci,
44
A. Pasqualetti,
28
R. Passaquieti,
18, 19
D. Passuello,
19
M. Patil,
142
B. Patricelli,
18, 19
B. L. Pearlstone,
44
C. Pedersen,
68
M. Pedraza,
1
R. Pedurand,
22, 161
A. Pele,
7
S. Penn,
162
C. J. Perez,
45
A. Perreca,
111, 95
H. P. Pfeiffer,
36, 117
M. Phelps,
8, 9
K. S. Phukon,
3
O. J. Piccinni,
112, 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,
90
S. Ponrathnam,
3
P. Popolizio,
28
E. K. Porter,
27
J. Powell,
151
A. K. Prajapati,
107
J. Prasad,
3
K. Prasai,
49
R. Prasanna,
129
G. Pratten,
99
T. Prestegard,
23
S. Privitera,
36
G. A. Prodi,
111, 95
L. G. Prokhorov,
62
O. Puncken,
8, 9
M. Punturo,
41
P. Puppo,
32
M. P
̈
urrer,
36
H. Qi,
23
V. Quetschke,
104
P. J. Quinonez,
34
E. A. Quintero,
1
R. Quitzow-James,
70
F. J. Raab,
45
H. Radkins,
45
N. Radulescu,
65
P. Raffai,
106
S. Raja,
61
C. Rajan,
61
B. Rajbhandari,
83
M. Rakhmanov,
104
K. E. Ramirez,
104
A. Ramos-Buades,
99
Javed Rana,
3
K. Rao,
59
P. Rapagnani,
112, 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,
112, 32
C. J. Richardson,
34
J. W. Richardson,
1
P. M. Ricker,
17
K. Riles,
125
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,
114
D. Rosi
́
nska,
163, 54
S. G. Rosofsky,
17
M. P. Ross,
164
S. Rowan,
44
A. R
̈
udiger,
8, 9,
‡
P. Ruggi,
28
G. Rutins,
165
K. Ryan,
45
S. Sachdev,
1
T. Sadecki,
45
M. Sakellariadou,
131
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
P. R. Saulson,
42
O. Sauter,
125
R. L. Savage,
45
P. Schale,
70
M. Scheel,
46
J. Scheuer,
59
P. Schmidt,
64
R. Schnabel,
139
R. M. S. Schofield,
70
A. Sch
̈
onbeck,
139
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,
166
N. Sennett,
36
D. Sentenac,
28
V. Sequino,
30, 31, 14
A. Sergeev,
134
Y. Setyawati,
8, 9
D. A. Shaddock,
21
T. Shaffer,
45
M. S. Shahriar,
59
M. B. Shaner,
110
L. Shao,
36
P. Sharma,
61
P. Shawhan,
76
H. Shen,
17
R. Shink,
167
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,
99
S. Sitmukhambetov,
104
V. Skliris,
68
B. J. J. Slagmolen,
21
T. J. Slaven-Blair,
63
J. R. Smith,
26
R. J. E. Smith,
6
S. Somala,
168
E. J. Son,
137
B. Sorazu,
44
F. Sorrentino,
60
T. Souradeep,
3
E. Sowell,
83
A. P. Spencer,
44
A. K. Srivastava,
107
V. Srivastava,
42
K. Staats,
59
C. Stachie,
65
M. Standke,
8, 9
D. A. Steer,
27
M. Steinke,
8, 9
J. Steinlechner,
139, 44
S. Steinlechner,
139
D. Steinmeyer,
8, 9
S. P. Stevenson,
151
D. Stocks,
49
R. Stone,
104
D. J. Stops,
11
K. A. Strain,
44
G. Stratta,
72, 73
S. E. Strigin,
62
A. Strunk,
45
R. Sturani,
169
A. L. Stuver,
170
V. Sudhir,
12
T. Z. Summerscales,
171
L. Sun,
1
S. Sunil,
107
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,
122
A. Taracchini,
36
J. D. Tasson,
93
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,
111, 95
Srishti Tiwari,
123
V. Tiwari,
68
K. Toland,
44
M. Tonelli,
18, 19
Z. Tornasi,
44
A. Torres-Forn
́
e,
172
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,
173, 19
R. Trudeau,
1
K. W. Tsang,
37
M. Tse,
12
R. Tso,
46
L. Tsukada,
81
D. Tsuna,
81
D. Tuyenbayev,
104
K. Ueno,
81
D. Ugolini,
174
C. S. Unnikrishnan,
123
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, 175
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,
164
G. Venugopalan,
1
D. Verkindt,
33
F. Vetrano,
72, 73
A. Vicer
́
e,
72, 73
A. D. Viets,
23
D. J. Vine,
165
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,
114
M. Wade,
114
R. Walet,
37
M. Walker,
26
L. Wallace,
1
S. Walsh,
23
G. Wang,
14, 19
H. Wang,
11
J. Z. Wang,
125
W. H. Wang,
104
Y. F. Wang,
90
R. L. Ward,
21
Z. A. Warden,
34
J. Warner,
45
M. Was,
33
J. Watchi,
100
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,
127, 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,
113
M. J. Yap,
21
M. Yazback,
48
D. W. Yeeles,
68
Hang Yu,
12
Haocun Yu,
12
S. H. R. Yuen,
90
M. Yvert,
33
A. K. Zadro
̇
zny,
104, 141
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
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
4
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
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
5
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
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
RESCEU, University of Tokyo, Tokyo, 113-0033, Japan.
82
Tsinghua University, Beijing 100084, China
83
Texas Tech University, Lubbock, TX 79409, USA
84
The University of Mississippi, University, MS 38677, USA
85
Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, I-00184 Roma, Italyrico Fermi, I-00184 Roma, Italy
86
The Pennsylvania State University, University Park, PA 16802, USA
87
National Tsing Hua University, Hsinchu City, 30013 Taiwan, Republic of China
88
Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia
89
University of Chicago, Chicago, IL 60637, USA
90
The Chinese University of Hong Kong, Shatin, NT, Hong Kong
91
Seoul National University, Seoul 08826, South Korea
92
Pusan National University, Busan 46241, South Korea
93
Carleton College, Northfield, MN 55057, USA
94
INAF, Osservatorio Astronomico di Padova, I-35122 Padova, Italy
95
INFN, Trento Institute for Fundamental Physics and Applications, I-38123 Povo, Trento, Italy
96
Dipartimento di Fisica, Universit`a degli Studi di Genova, I-16146 Genova, Italy
97
OzGrav, University of Melbourne, Parkville, Victoria 3010, Australia
98
Columbia University, New York, NY 10027, USA
99
Universitat de les Illes Balears, IAC3—IEEC, E-07122 Palma de Mallorca, Spain
100
Universit ́e Libre de Bruxelles, Brussels 1050, Belgium
101
Sonoma State University, Rohnert Park, CA 94928, USA
102
Departamento de Matem ́aticas, Universitat de Val`encia, E-46100 Burjassot, Val`encia, Spain
103
University of Rhode Island, Kingston, RI 02881, USA
104
The University of Texas Rio Grande Valley, Brownsville, TX 78520, USA
105
Bellevue College, Bellevue, WA 98007, USA
106
MTA-ELTE Astrophysics Research Group, Institute of Physics, E ̈otv ̈os University, Budapest 1117, Hungary
107
Institute for Plasma Research, Bhat, Gandhinagar 382428, India
108
The University of Sheffield, Sheffield S10 2TN, United Kingdom
109
Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Universit`a di Parma, I-43124 Parma, Italy
110
California State University, Los Angeles, 5151 State University Dr, Los Angeles, CA 90032, USA
6
111
Universit`a di Trento, Dipartimento di Fisica, I-38123 Povo, Trento, Italy
112
Universit`a di Roma ’La Sapienza,’ I-00185 Roma, Italy
113
Colorado State University, Fort Collins, CO 80523, USA
114
Kenyon College, Gambier, OH 43022, USA
115
Christopher Newport University, Newport News, VA 23606, USA
116
National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
117
Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, Ontario M5S 3H8, Canada
118
Observatori Astron`omic, Universitat de Val`encia, E-46980 Paterna, Val`encia, Spain
119
School of Mathematics, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
120
Institute Of Advanced Research, Gandhinagar 382426, India
121
Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
122
University of Szeged, D ́om t ́er 9, Szeged 6720, Hungary
123
Tata Institute of Fundamental Research, Mumbai 400005, India
124
INAF, Osservatorio Astronomico di Capodimonte, I-80131, Napoli, Italy
125
University of Michigan, Ann Arbor, MI 48109, USA
126
American University, Washington, D.C. 20016, USA
127
GRAPPA, Anton Pannekoek Institute for Astronomy and Institute of High-Energy Physics, University of Amsterdam, Science Park
904, 1098 XH Amsterdam, The Netherlands
128
Delta Institute for Theoretical Physics, Science Park 904, 1090 GL Amsterdam, The Netherlands
129
Directorate of Construction, Services & Estate Management, Mumbai 400094 India
130
University of Bia lystok, 15-424 Bia lystok, Poland
131
King’s College London, University of London, London WC2R 2LS, United Kingdom
132
University of Southampton, Southampton SO17 1BJ, United Kingdom
133
University of Washington Bothell, Bothell, WA 98011, USA
134
Institute of Applied Physics, Nizhny Novgorod, 603950, Russia
135
Ewha Womans University, Seoul 03760, South Korea
136
Inje University Gimhae, South Gyeongsang 50834, South Korea
137
National Institute for Mathematical Sciences, Daejeon 34047, South Korea
138
Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
139
Universit ̈at Hamburg, D-22761 Hamburg, Germany
140
Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
141
NCBJ, 05-400
́
Swierk-Otwock, Poland
142
Institute of Mathematics, Polish Academy of Sciences, 00656 Warsaw, Poland
143
Cornell University, Ithaca, NY 14850, USA
144
Hillsdale College, Hillsdale, MI 49242, USA
145
Hanyang University, Seoul 04763, South Korea
146
Korea Astronomy and Space Science Institute, Daejeon 34055, South Korea
147
NASA Marshall Space Flight Center, Huntsville, AL 35811, USA
148
Dipartimento di Matematica e Fisica, Universit`a degli Studi Roma Tre, I-00146 Roma, Italy
149
INFN, Sezione di Roma Tre, I-00146 Roma, Italy
150
ESPCI, CNRS, F-75005 Paris, France
151
OzGrav, Swinburne University of Technology, Hawthorn VIC 3122, Australia
152
University of Portsmouth, Portsmouth, PO1 3FX, United Kingdom
153
Southern University and A&M College, Baton Rouge, LA 70813, USA
154
College of William and Mary, Williamsburg, VA 23187, USA
155
Centre Scientifique de Monaco, 8 quai Antoine Ier, MC-98000, Monaco
156
Indian Institute of Technology Madras, Chennai 600036, India
157
INFN Sezione di Torino, Via P. Giuria 1, I-10125 Torino, Italy
158
Institut des Hautes Etudes Scientifiques, F-91440 Bures-sur-Yvette, France
159
IISER-Kolkata, Mohanpur, West Bengal 741252, India
160
Whitman College, 345 Boyer Avenue, Walla Walla, WA 99362 USA
161
Universit ́e de Lyon, F-69361 Lyon, France
162
Hobart and William Smith Colleges, Geneva, NY 14456, USA
163
Janusz Gil Institute of Astronomy, University of Zielona G ́ora, 65-265 Zielona G ́ora, Poland
7
164
University of Washington, Seattle, WA 98195, USA
165
SUPA, University of the West of Scotland, Paisley PA1 2BE, United Kingdom
166
Indian Institute of Technology, Gandhinagar Ahmedabad Gujarat 382424, India
167
Universit ́e de Montr ́eal/Polytechnique, Montreal, Quebec H3T 1J4, Canada
168
Indian Institute of Technology Hyderabad, Sangareddy, Khandi, Telangana 502285, India
169
International Institute of Physics, Universidade Federal do Rio Grande do Norte, Natal RN 59078-970, Brazil
170
Villanova University, 800 Lancaster Ave, Villanova, PA 19085, USA
171
Andrews University, Berrien Springs, MI 49104, USA
172
Max Planck Institute for Gravitationalphysik (Albert Einstein Institute), D-14476 Potsdam-Golm, Germany
173
Universit`a di Siena, I-53100 Siena, Italy
174
Trinity University, San Antonio, TX 78212, USA
175
Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
ABSTRACT
We describe directed searches for continuous gravitational waves from sixteen well localized candidate neutron stars
assuming none of the stars has a binary companion. The searches were directed toward fifteen supernova remnants and
Fomalhaut b, an extrasolar planet candidate which has been suggested to be a nearby old neutron star. Each search
covered a broad band of frequencies and first and second time derivatives. After coherently integrating spans of data
from the first Advanced LIGO observing run of 3.5–53.7 days per search, applying data-based vetoes and discounting
known instrumental artifacts, we found no astrophysical signals. We set upper limits on intrinsic gravitational wave
strain as strict as 1
×
10
−
25
, on fiducial neutron star ellipticity as strict as 2
×
10
−
9
, and on fiducial
r
-mode amplitude
as strict as 3
×
10
−
8
.
Keywords:
gravitational waves — stars: neutron — supernova remnants
∗
Deceased, February 2018.
†
Deceased, November 2017.
‡
Deceased, July 2018.
8
1.
INTRODUCTION
With the detections of several binary black hole merg-
ers (Abbott et al. 2016c,b, 2017e,g,f) and one binary
neutron star merger (Abbott et al. 2017h) seen also
in electromagnetic waves (Abbott et al. 2017i), Ad-
vanced LIGO and Virgo have spectacularly inaugurated
the field of gravitational wave (GW) astronomy. While
the binary neutron star merger has had far-reaching
implications for our knowledge of neutron star matter
(De et al. 2018; Abbott et al. 2018), a continuous GW
signal could teach us even more—not just about bulk
properties but internal magnetic fields, the extent and
strength of crystalline phases, and potentially other mi-
crophysics of extreme matter (Owen 2009; Glampedakis
& Gualtieri 2017).
Young isolated neutron stars are promising sources
of continuous GWs. The spin-downs of young pulsars
are rapid enough to include significant continuous GW
emission, as shown by the latest GW search for known
pulsars (Abbott et al. 2017d,c). Theoretical arguments
suggest that
r
-modes (oscillations dominated by the
Coriolis force) might remain unstable and detectable in
neutron stars up to a few thousand years old (Owen
2010, and references therein). Most young supernova
remnants (SNRs) do not contain known pulsars (Green
2014). On the other hand, many of these SNRs contain
small pulsar wind nebulae (PWNe), central compact ob-
jects (CCOs), or other well localized non-pulsing candi-
date neutron stars. Also, some of these SNRs are young
enough that a neutron star could not have been kicked
far, and thus the star can be considered well localized
even if it is not seen at all. GW searches directed at
single sky positions can significantly improve on the sen-
sitivities of all-sky surveys, even while needing to cover
a wide band of possible GW frequencies and first and
second time derivatives due to lack of pulsations from
the object (Wette et al. 2008). This makes non-pulsing
isolated neutron stars attractive targets for continuous
GW searches if they are well localized.
Directed GW searches for isolated neutron stars have
been published targeting SNRs (Abadie et al. 2010;
Abadie et al. 2011; Aasi et al. 2015; Sun et al. 2016;
Zhu et al. 2016; Abbott et al. 2017b) and promising lo-
cations including the galactic center (Abadie et al. 2011;
Aasi et al. 2013; Abbott et al. 2017b) and the core of a
nearby globular cluster—where multi-body interactions
might effectively rejuvenate some neutron stars’ contin-
uous GW emission (Abbott et al. 2017j). The only such
search of data from advanced interferometers so far (Ab-
bott et al. 2017b) employed methods from stochastic
background searches which, while quick to implement,
are not as sensitive as continuous wave search methods.
Here we present the first directed continuous wave
searches for isolated non-pulsing neutron stars in data
from the first Advanced LIGO observing run (O1). We
used an extension of the coherent data analysis pipeline
used in Abadie et al. (2010) and Aasi et al. (2015), to
which this paper is a sequel. The improved noise curve
(with respect to initial LIGO and Virgo) means that we
can search more targets with sensitivity beating the indi-
rect upper limit on GW emission due to energy conserva-
tion (Wette et al. 2008) based on the age of the neutron
star (similar to the spin-down limit for known pulsars).
We include not only more supernova remnants, but also
the exoplanet candidate Fomalhaut b, which has been
proposed to be an old nearby neutron star (Neuh ̈auser
et al. 2015)—close enough that it is an attractive tar-
get in spite of being much older than the others. We
do not include SN 1987A because it is so young that
the possible spin-down parameter space is too large to
cover with a coherent wide band search and a reasonable
computational cost.
2.
SEARCHES
2.1.
Methods
These searches were based on the multi-interferometer
F
-statistic (Jaranowski et al. 1998; Cutler & Schutz
2005). The
F
-statistic accounts for the modulation of
the signal due to the daily rotation of the detectors
by adding the outputs of sinusoidal matched filters in
quadrature. For these searches the frequency evolution
of each filter, in the reference frame of the solar system
barycenter, was given by
f
(
t
) =
f
+
̇
f
(
t
−
t
0
) +
1
2
̈
f
(
t
−
t
0
)
2
,
(1)
where
t
0
is the beginning of the observation and the
frequency derivatives are evaluated at that time and in
a slight abuse of notation we use a simple
f
for
f
(
t
0
)
.
Hence these filters are designed to detect neutron stars
without binary companions whose spin-down is not too
fast (requiring third or higher frequency derivatives) or
too irregular (having significant timing noise or glitches)
during the observation. In stationary Gaussian noise,
2
F
is drawn from a
χ
2
distribution with four degrees
of freedom, which for loud signals makes the ampli-
tude signal-to-noise ratio roughly
√
F
/
2
.
If a signal is
present, the
χ
2
is noncentral.
We used data from LIGO O1, but none from Virgo
because that interferometer was down for upgrades dur-
ing O1. At the frequencies to which LIGO was most
sensitive (about 100-300 Hz), the strain noise amplitude
was about 3–4 times lower than in the sixth LIGO sci-
ence run (S6) (Abbott et al. 2016a). However there were
9
many more spectral lines due to instrumental artifacts
than in S6, which complicated the analysis. We used the
calibration described in Abbott et al. (2017d), which is
an update of the first O1 calibration described in Abbott
et al. (2017a). Hence, as in Abbott et al. (2017d), our
upper limits on strain are uncertain by at least 14%.
Like many other continuous GW searches, ours used
data in the form of short Fourier transforms (SFTs)
of duration 1800 s, high pass filtered and Tukey win-
dowed to reduce artifacts, recording only frequencies up
to 2 kHz.
While each search targeted a specific direction (right
ascension and declination), each had to cover a broad
band of frequencies and first and second derivatives.
That is, a bank of signal templates was required, con-
structed to cover the parameter space (
f,
̇
f,
̈
f
) with suf-
ficient density (Whitbeck 2006; Wette et al. 2008). We
chose coverage such that the maximum loss of power
signal-to-noise ratio due to mismatch between the sig-
nal and the nearest template (Owen 1996; Brady et al.
1998) was no worse than 20%, a common choice in con-
tinuous GW analyses. Given the parameter choices de-
scribed below, this resulted in 10
12
–10
13
templates for
most searches, with the Cas A search getting more than
10
14
since it was allocated ten times the computing cy-
cles of each other search.
All searches ran on the Atlas computing cluster at the
Max Planck Institute for Gravitational Physics (Albert
Einstein Institute) in Hanover, Germany using the same
tag (
S6SNRSearch
) of the LALSuite software package
1
as in Aasi et al. (2015) although the controlling scripts
were upgraded. Most searches used roughly 10
5
core
hours (split into roughly 3
×
10
4
batch jobs) and Cas A
used more than 10
6
(split into roughly 3
×
10
5
jobs).
The splitting into jobs was used in the vetoes and other
post-processing described in Sec. 2.4. Post-processing
for each search used at most of order ten percent of the
core hours dedicated to the search. Several terabytes of
search results were written to disk.
2.2.
Target List
Our choice of targets required that a search of fixed
computational cost be sensitive enough to detect the
strongest continuous GW signal consistent with broad
conservation of energy considerations. As introduced by
Wette et al. (2008), the strongest possible signal based
on the age
a
and distance
D
of the source,
h
age
0
= 1
.
26
×
10
−
24
(
3.30 kpc
D
)(
300 yr
a
)
1
/
2
,
(2)
1
Available at
https://github.com/lscsoft/lalsuite-archive
is analogous to the spin-down limit for known pulsars
and indicates the strongest possible intrinsic strain pro-
duced by an object whose unknown spin-down is entirely
due to GW emission and has been since birth. The in-
trinsic strain
h
0
(Jaranowski et al. 1998) characterizes
the GW metric perturbation without reference to any
particular orientation or polarization, and hence is typi-
cally a factor 2–3 greater than the strain response mea-
sured by the interferometers. The indirect limit
h
age
0
is
slightly different for
r
-mode emission (Owen 2010) than
for the mass quadrupole source tacitly assumed above
and in most of the literature, but we neglect this small
difference. Due to uncertainties in the neutron star mass
and equation of state,
h
age
0
is uncertain by of order 50%,
which we also neglect.
To choose directions to search, we started from the
Green catalog of supernova remnants (Green 2014). We
picked x-ray point sources (CCOs or candidate CCOs),
small PWNe, and in some cases relatively young SNRs
where any neutron star could not yet have moved far.
We selected only targets with age and distance estimates
so that we could evaluate
h
age
0
.
In some cases there is a
wide range of estimates in the literature, leading to sig-
nificant differences in
h
age
0
.
In most cases we used the
most optimistic estimates, yielding the highest
h
age
0
but
also the most difficult search over the widest band of fre-
quency and spin-down parameters. In addition to this
wide search using the optimistic age and distance, we
did a deep search using the most pessimistic age and
distance in cases where the strain sensitivity would im-
prove over the wide search by a factor of roughly
√
2
.
The resulting targets and chosen parameters are
shown in Table 1.
We now briefly summarize each
target and the provenance of the parameters used for it.
G1.9+0.3
—Currently the youngest known SNR in the
galaxy (Reynolds et al. 2008). Several arguments favor
it being a Type Ia (Reynolds et al. 2008), which would
leave no neutron star behind, but this is not definite
and the remnant’s youth makes it an interesting target
on the chance that it is not Type Ia. We used the po-
sition of the center of the remnant from the discovery
paper (Reich et al. 1984). At maximum kick velocity
any neutron star could have moved only a few arcsec-
onds, which is not an issue for our searches. The age
and distance shown are from the “rediscovery” paper
(Reynolds et al. 2008), though the latter is a nominal
galactic center distance.
G15.9+0.2
—The CCO was discovered in
Chandra
data by Reynolds et al. (2006). We used the lower limit
on age and the galactic center distance estimate from the
same paper, though both quantities may be significantly
greater (Klochkov et al. 2016).