of 14
Search for Transient Gravitational-wave Signals Associated with Magnetar Bursts
during Advanced LIGO
s Second Observing Run
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. Arène
27
, N. Arnaud
25
,
28
, S. Ascenzi
29
,
30
, G. Ashton
6
,
S. M. Aston
7
, P. Astone
31
, F. Aubin
32
, P. Aufmuth
9
, K. AultONeal
33
, C. Austin
2
, V. Avendano
34
, A. Avila-Alvarez
26
,
S. Babak
27
,
35
, P. Bacon
27
, F. Badaracco
14
,
15
, M. K. M. Bader
36
, S. Bae
37
, P. T. Baker
38
, F. Baldaccini
39
,
40
, G. Ballardin
28
,
S. W. Ballmer
41
, S. Banagiri
42
, J. C. Barayoga
1
, S. E. Barclay
43
, B. C. Barish
1
, D. Barker
44
, K. Barkett
45
, S. Barnum
12
, F. Barone
4
,
5
,
B. Barr
43
, L. Barsotti
12
, M. Barsuglia
27
, D. Barta
46
, J. Bartlett
44
, I. Bartos
47
, R. Bassiri
48
, A. Basti
18
,
19
, M. Bawaj
40
,
49
,
J. C. Bayley
43
, M. Bazzan
50
,
51
, B. Bécsy
52
, M. Bejger
27
,
53
, I. Belahcene
25
, A. S. Bell
43
, D. Beniwal
54
, B. K. Berger
48
,
G. Bergmann
8
,
9
, S. Bernuzzi
55
,
56
, J. J. Bero
57
, C. P. L. Berry
58
, D. Bersanetti
59
, A. Bertolini
36
, J. Betzwieser
7
, R. Bhandare
60
,
J. Bidler
26
, I. A. Bilenko
61
, S. A. Bilgili
38
, G. Billingsley
1
, J. Birch
7
, R. Birney
24
, O. Birnholtz
57
, S. Biscans
1
,
12
, S. Biscoveanu
6
,
A. Bisht
9
, M. Bitossi
19
,
28
, M. A. Bizouard
25
, J. K. Blackburn
1
, C. D. Blair
7
, D. G. Blair
62
, R. M. Blair
44
, S. Bloemen
63
, N. Bode
8
,
9
,
M. Boer
64
, Y. Boetzel
65
, G. Bogaert
64
, F. Bondu
66
, E. Bonilla
48
, R. Bonnand
32
, P. Booker
8
,
9
, B. A. Boom
36
, C. D. Booth
67
,
R. Bork
1
, V. Boschi
28
, S. Bose
3
,
68
, K. Bossie
7
, V. Bossilkov
62
, J. Bosveld
62
, Y. Bouffanais
27
, A. Bozzi
28
, C. Bradaschia
19
,
P. R. Brady
23
, A. Bramley
7
, M. Branchesi
14
,
15
, J. E. Brau
69
, T. Briant
70
, J. H. Briggs
43
, F. Brighenti
71
,
72
, A. Brillet
64
,
M. Brinkmann
8
,
9
, V. Brisson
25
,
177
, P. Brockill
23
, A. F. Brooks
1
, D. D. Brown
54
, S. Brunett
1
, A. Buikema
12
, T. Bulik
73
,
H. J. Bulten
36
,
74
, A. Buonanno
35
,
75
, D. Buskulic
32
, C. Buy
27
, R. L. Byer
48
, M. Cabero
8
,
9
, L. Cadonati
76
, G. Cagnoli
22
,
77
,
C. Cahillane
1
, J. Calderón Bustillo
6
, T. A. Callister
1
, E. Calloni
5
,
78
, J. B. Camp
79
, W. A. Campbell
6
, M. Canepa
59
,
80
,
K. C. Cannon
81
, H. Cao
54
, J. Cao
82
, E. Capocasa
27
, F. Carbognani
28
, S. Caride
83
, M. F. Carney
58
, G. Carullo
18
,
J. Casanueva Diaz
19
, C. Casentini
29
,
30
, S. Caudill
36
, M. Cavaglià
84
, F. Cavalier
25
, R. Cavalieri
28
, G. Cella
19
, P. Cerdá-Durán
20
,
G. Cerretani
18
,
19
, E. Cesarini
30
,
85
, O. Chaibi
64
, K. Chakravarti
3
, S. J. Chamberlin
86
, M. Chan
43
, S. Chao
87
, P. Charlton
88
,
E. A. Chase
58
, E. Chassande-Mottin
27
, D. Chatterjee
23
, M. Chaturvedi
60
, B. D. Cheeseboro
38
, H. Y. Chen
89
, X. Chen
62
, Y. Chen
45
,
H.-P. Cheng
47
, C. K. Cheong
90
, H. Y. Chia
47
, A. Chincarini
59
, A. Chiummo
28
, G. Cho
91
,H.S.Cho
92
, M. Cho
75
,
N. Christensen
64
,
93
, Q. Chu
62
, S. Chua
70
, K. W. Chung
90
, S. Chung
62
, G. Ciani
50
,
51
, A. A. Ciobanu
54
, R. Ciol
fi
94
,
95
, F. Cipriano
64
,
A. Cirone
59
,
80
, F. Clara
44
, J. A. Clark
76
, P. Clearwater
96
, F. Cleva
64
, C. Cocchieri
84
, E. Coccia
14
,
15
, P.-F. Cohadon
70
, D. Cohen
25
,
R. Colgan
97
, M. Colleoni
98
, C. G. Collette
99
, C. Collins
11
, L. R. Cominsky
100
, M. Constancio, Jr.
13
, L. Conti
51
, S. J. Cooper
11
,
P. Corban
7
, T. R. Corbitt
2
, I. Cordero-Carrión
101
, K. R. Corley
97
, N. Cornish
52
, A. Corsi
83
, S. Cortese
28
, C. A. Costa
13
, R. Cotesta
35
,
M. W. Coughlin
1
, S. B. Coughlin
58
,
67
, J.-P. Coulon
64
, S. T. Countryman
97
, P. Couvares
1
, P. B. Covas
98
, E. E. Cowan
76
,
D. M. Coward
62
, M. J. Cowart
7
, D. C. Coyne
1
, R. Coyne
102
, J. D. E. Creighton
23
, T. D. Creighton
103
, J. Cripe
2
, M. Croquette
70
,
S. G. Crowder
104
, T. J. Cullen
2
, A. Cumming
43
, L. Cunningham
43
, E. Cuoco
28
, T. Dal Canton
79
, G. Dálya
105
, S. L. Danilishin
8
,
9
,
S. D
Antonio
30
, K. Danzmann
8
,
9
, A. Dasgupta
106
, C. F. Da Silva Costa
47
, L. E. H. Datrier
43
, V. Dattilo
28
, I. Dave
60
, M. Davier
25
,
D. Davis
41
, E. J. Daw
107
, D. DeBra
48
, M. Deenadayalan
3
, J. Degallaix
22
, M. De Laurentis
5
,
78
, S. Deléglise
70
, W. Del Pozzo
18
,
19
,
L. M. DeMarchi
58
, N. Demos
12
, T. Dent
8
,
9
,
108
, R. De Pietri
56
,
109
, J. Derby
26
, R. De Rosa
5
,
78
, C. De Rossi
22
,
28
, R. DeSalvo
110
,
O. de Varona
8
,
9
, S. Dhurandhar
3
, M. C. Díaz
103
, T. Dietrich
36
, L. Di Fiore
5
, M. Di Giovanni
95
,
111
, T. Di Girolamo
5
,
78
,
A. Di Lieto
18
,
19
, B. Ding
99
, S. Di Pace
31
,
112
, I. Di Palma
31
,
112
, F. Di Renzo
18
,
19
, A. Dmitriev
11
, Z. Doctor
89
, F. Donovan
12
,
K. L. Dooley
67
,
84
, S. Doravari
8
,
9
, I. Dorrington
67
, T. P. Downes
23
, M. Drago
14
,
15
, J. C. Driggers
44
,Z.Du
82
, J.-G. Ducoin
25
,
P. Dupej
43
, S. E. Dwyer
44
, P. J. Easter
6
, T. B. Edo
107
, M. C. Edwards
93
,A.Ef
fl
er
7
, P. Ehrens
1
, J. Eichholz
1
, S. S. Eikenberry
47
,
M. Eisenmann
32
, R. A. Eisenstein
12
, R. C. Essick
89
, H. Estelles
98
, D. Estevez
32
, Z. B. Etienne
38
, T. Etzel
1
, M. Evans
12
,
T. M. Evans
7
, V. Fafone
14
,
29
,
30
, H. Fair
41
, S. Fairhurst
67
, X. Fan
82
, S. Farinon
59
, B. Farr
69
, W. M. Farr
11
, E. J. Fauchon-Jones
67
,
M. Favata
34
, M. Fays
107
, M. Fazio
113
, C. Fee
114
, J. Feicht
1
, M. M. Fejer
48
, 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
41
,
115
,
J. M. Fishner
12
, M. Fitz-Axen
42
, R. Flaminio
32
,
116
, M. Fletcher
43
, E. Flynn
26
, H. Fong
117
, J. A. Font
20
,
118
, P. W. F. Forsyth
21
,
J.-D. Fournier
64
, S. Frasca
31
,
112
, F. Frasconi
19
, Z. Frei
105
, A. Freise
11
, R. Frey
69
, V. Frey
25
, P. Fritschel
12
, V. V. Frolov
7
, P. Fulda
47
,
M. Fyffe
7
, H. A. Gabbard
43
, B. U. Gadre
3
, S. M. Gaebel
11
, J. R. Gair
119
, L. Gammaitoni
39
, M. R. Ganija
54
, S. G. Gaonkar
3
,
A. Garcia
26
, C. García-Quirós
98
, F. Garu
fi
5
,
78
, B. Gateley
44
, S. Gaudio
33
, G. Gaur
120
, V. Gayathri
121
, G. Gemme
59
, E. Genin
28
,
A. Gennai
19
, D. George
17
, J. George
60
, L. Gergely
122
, V. Germain
32
, S. Ghonge
76
, Abhirup Ghosh
16
, Archisman Ghosh
36
,
S. Ghosh
23
, B. Giacomazzo
95
,
111
, J. A. Giaime
2
,
7
, K. D. Giardina
7
, A. Giazotto
19
,
178
, K. Gill
33
, G. Giordano
4
,
5
, L. Glover
110
,
P. Godwin
86
, E. Goetz
44
, R. Goetz
47
, B. Goncharov
6
, G. González
2
, J. M. Gonzalez Castro
18
,
19
, A. Gopakumar
123
,
M. L. Gorodetsky
61
, S. E. Gossan
1
, M. Gosselin
28
, R. Gouaty
32
, A. Grado
5
,
124
, C. Graef
43
, M. Granata
22
, A. Grant
43
, S. Gras
12
,
P. Grassia
1
, C. Gray
44
, R. Gray
43
, G. Greco
71
,
72
, A. C. Green
11
,
47
, R. Green
67
, E. M. Gretarsson
33
, P. Groot
63
, H. Grote
67
,
S. Grunewald
35
, P. Gruning
25
, G. M. Guidi
71
,
72
, H. K. Gulati
106
, Y. Guo
36
, A. Gupta
86
, M. K. Gupta
106
, E. K. Gustafson
1
,
R. Gustafson
125
, L. Haegel
98
, O. Halim
14
,
15
, B. R. Hall
68
, E. D. Hall
12
, E. Z. Hamilton
67
, G. Hammond
43
, M. Haney
65
,
The Astrophysical Journal,
874:163
(
14pp
)
, 2019 April 1
https:
//
doi.org
/
10.3847
/
1538-4357
/
ab0e15
© 2019. The American Astronomical Society. All rights reserved.
1
M. M. Hanke
8
,
9
, J. Hanks
44
, 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
35
, C.-J. Haster
117
, K. Haughian
43
, F. J. Hayes
43
, J. Healy
57
, A. Heidmann
70
, M. C. Heintze
7
, H. Heitmann
64
, P. Hello
25
,
G. Hemming
28
, M. Hendry
43
, I. S. Heng
43
, J. Hennig
8
,
9
, A. W. Heptonstall
1
, Francisco Hernandez Vivanco
6
, M. Heurs
8
,
9
, S. Hild
43
,
T. Hinderer
36
,
127
,
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
67
, C. Horst
23
, J. Hough
43
, E. J. Howell
62
, C. G. Hoy
67
, A. Hreibi
64
, E. A. Huerta
17
, D. Huet
25
, B. Hughey
33
, M. Hulko
1
,
S. Husa
98
, S. H. Huttner
43
, T. Huynh-Dinh
7
, B. Idzkowski
73
, A. Iess
29
,
30
, C. Ingram
54
, R. Inta
83
, G. Intini
31
,
112
, B. Irwin
114
,
H. N. Isa
43
, J.-M. Isac
70
, M. Isi
1
, B. R. Iyer
16
, K. Izumi
44
, T. Jacqmin
70
, S. J. Jadhav
129
, K. Jani
76
, N. N. Janthalur
129
,
P. Jaranowski
130
, A. C. Jenkins
131
, J. Jiang
47
, D. S. Johnson
17
, A. W. Jones
11
, D. I. Jones
132
, R. Jones
43
, R. J. G. Jonker
36
,L.Ju
62
,
J. Junker
8
,
9
, C. V. Kalaghatgi
67
, V. Kalogera
58
, B. Kamai
1
, S. Kandhasamy
84
, G. Kang
37
, J. B. Kanner
1
, S. J. Kapadia
23
, S. Karki
69
,
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
44
,
N. V. Keerthana
3
, F. Kéfélian
64
, D. Keitel
43
, R. Kennedy
107
,J.S.Key
133
, F. Y. Khalili
61
, H. Khan
26
, I. Khan
14
,
30
, S. Khan
8
,
9
,
Z. Khan
106
, E. A. Khazanov
134
, M. Khursheed
60
, N. Kijbunchoo
21
, Chunglee Kim
135
, J. C. Kim
136
, K. Kim
90
, W. Kim
54
,
W. S. Kim
137
, Y.-M. Kim
138
, C. Kimball
58
, E. J. King
54
, P. J. King
44
, M. Kinley-Hanlon
126
, R. Kirchhoff
8
,
9
, J. S. Kissel
44
,
L. Kleybolte
139
, J. H. Klika
23
, S. Klimenko
47
, T. D. Knowles
38
, P. Koch
8
,
9
, S. M. Koehlenbeck
8
,
9
, G. Koekoek
36
,
140
, S. Koley
36
,
V. Kondrashov
1
, A. Kontos
12
, N. Koper
8
,
9
, M. Korobko
139
, W. Z. Korth
1
, I. Kowalska
73
, D. B. Kozak
1
, V. Kringel
8
,
9
,
N. Krishnendu
141
, A. Królak
142
,
143
, G. Kuehn
8
,
9
, A. Kumar
129
, P. Kumar
144
, R. Kumar
106
, S. Kumar
16
, L. Kuo
87
, A. Kutynia
142
,
S. Kwang
23
, B. D. Lackey
35
, K. H. Lai
90
, T. L. Lam
90
, M. Landry
44
, B. B. Lane
12
, R. N. Lang
145
, J. Lange
57
, B. Lantz
48
,
R. K. Lanza
12
, A. Lartaux-Vollard
25
, P. D. Lasky
6
, M. Laxen
7
, A. Lazzarini
1
, C. Lazzaro
51
, P. Leaci
31
,
112
, S. Leavey
8
,
9
,
Y. K. Lecoeuche
44
, C. H. Lee
92
, H. K. Lee
146
, H. M. Lee
147
, H. W. Lee
136
, J. Lee
91
, K. Lee
43
, J. Lehmann
8
,
9
, A. Lenon
38
,
N. Leroy
25
, N. Letendre
32
, Y. Levin
6
,
97
,J.Li
82
,K.J.L.Li
90
,T.G.F.Li
90
,X.Li
45
, F. Lin
6
, F. Linde
36
, S. D. Linker
110
,
T. B. Littenberg
148
, J. Liu
62
, X. Liu
23
,R.K.L.Lo
1
,
90
, N. A. Lockerbie
24
, L. T. London
67
, 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
57
, G. Lovelace
26
, M. E. Lower
152
, H. Lück
8
,
9
,
D. Lumaca
29
,
30
, A. P. Lundgren
153
, R. Lynch
12
,Y.Ma
45
, R. Macas
67
, S. Macfoy
24
, M. MacInnis
12
, D. M. Macleod
67
,
A. Macquet
64
, F. Magaña-Sandoval
41
, L. Magaña Zertuche
84
, R. M. Magee
86
, E. Majorana
31
, I. Maksimovic
151
, A. Malik
60
,
N. Man
64
, V. Mandic
42
, V. Mangano
43
, G. L. Mansell
12
,
44
, M. Manske
21
,
23
, M. Mantovani
28
, F. Marchesoni
40
,
49
, F. Marion
32
,
S. Márka
97
, Z. Márka
97
, C. Markakis
10
,
17
, A. S. Markosyan
48
, A. Markowitz
1
, E. Maros
1
, A. Marquina
101
, S. Marsat
35
,
F. Martelli
71
,
72
, I. W. Martin
43
, R. M. Martin
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2
Louisiana State University, Baton Rouge, LA 70803, USA
3
Inter-University Centre for Astronomy and Astrophysics, Pune 411007, India
4
Università 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
)
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9
Leibniz Universität Hannover, D-30167 Hannover, Germany
10
University of Cambridge, Cambridge CB2 1TN, UK
11
University of Birmingham, Birmingham B15 2TT, UK
12
LIGO, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
13
Instituto Nacional de Pesquisas Espaciais, 12227-010 São José dos Campos, São Paulo, Brazil
14
Gran Sasso Science Institute
(
GSSI
)
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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
Università di Pisa, I-56127 Pisa, Italy
19
INFN, Sezione di Pisa, I-56127 Pisa, Italy
20
Departamento de Astronomía y Astrof
ísica, Universitat de València, E-
46100 Burjassot, València, Spain
21
OzGrav, Australian National University, Canberra, Australian Capital Territory 0200, Australia
22
Laboratoire des Matériaux Avancés
(
LMA
)
, CNRS
/
IN2P3, F-69622 Villeurbanne, France
23
University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
24
SUPA, University of Strathclyde, Glasgow G1 1XQ, UK
25
LAL, Univ. Paris-Sud, CNRS
/
IN2P3, Université Paris-Saclay, F-91898 Orsay, France
26
California State University Fullerton, Fullerton, CA 92831, USA
27
APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS
/
IN2P3, CEA
/
Irfu, Observatoire de Paris, Sorbonne Paris Cité, F-75205 Paris Cedex 13,
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28
European Gravitational Observatory
(
EGO
)
, I-56021 Cascina, Pisa, Italy
29
Università di Roma Tor Vergata, I-00133 Roma, Italy
30
INFN, Sezione di Roma Tor Vergata, I-00133 Roma, Italy
31
INFN, Sezione di Roma, I-00185 Roma, Italy
32
Laboratoire d
Annecy de Physique des Particules
(
LAPP
)
, Univ. Grenoble Alpes, Université Savoie Mont Blanc, CNRS
/
IN2P3, F-74941 Annecy, France
33
Embry-Riddle Aeronautical University, Prescott, AZ 86301, USA
34
Montclair State University, Montclair, NJ 07043, USA
35
Max Planck Institute for Gravitational Physics
(
Albert Einstein Institute
)
, D-14476 Potsdam-Golm, Germany
36
Nikhef, Science Park 105, 1098 XG Amsterdam, The Netherlands
37
Korea Institute of Science and Technology Information, Daejeon 34141, Republic of Korea
38
West Virginia University, Morgantown, WV 26506, USA
3
The Astrophysical Journal,
874:163
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14pp
)
, 2019 April 1
Abbott et al.
39
Università di Perugia, I-06123 Perugia, Italy
40
INFN, Sezione di Perugia, I-06123 Perugia, Italy
41
Syracuse University, Syracuse, NY 13244, USA
42
University of Minnesota, Minneapolis, MN 55455, USA
43
SUPA, University of Glasgow, Glasgow G12 8QQ, UK
44
LIGO Hanford Observatory, Richland, WA 99352, USA
45
Caltech CaRT, Pasadena, CA 91125, USA
46
Wigner RCP, RMKI, H-1121 Budapest, Konkoly Thege Miklós út 29-33, Hungary
47
University of Florida, Gainesville, FL 32611, USA
48
Stanford University, Stanford, CA 94305, USA
49
Università di Camerino, Dipartimento di Fisica, I-62032 Camerino, Italy
50
Università di Padova, Dipartimento di Fisica e Astronomia, I-35131 Padova, Italy
51
INFN, Sezione di Padova, I-35131 Padova, Italy
52
Montana State University, Bozeman, MT 59717, USA
53
Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, 00-716, Warsaw, Poland
54
OzGrav, University of Adelaide, Adelaide, South Australia 5005, Australia
55
Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, D-07743 Jena, Germany
56
INFN, Sezione di Milano Bicocca, Gruppo Collegato di Parma, I-43124 Parma, Italy
57
Rochester Institute of Technology, Rochester, NY 14623, USA
58
Center for Interdisciplinary Exploration & Research in Astrophysics
(
CIERA
)
, Northwestern University, Evanston, IL 60208, USA
59
INFN, Sezione di Genova, I-16146 Genova, Italy
60
RRCAT, Indore, Madhya Pradesh 452013, India
61
Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
62
OzGrav, University of Western Australia, Crawley, Western Australia 6009, Australia
63
Department of Astrophysics
/
IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands
64
Artemis, Université Côte d
Azur, Observatoire Côte d
Azur, CNRS, CS 34229, F-06304 Nice Cedex 4, France
65
Physik-Institut, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
66
Univ Rennes, CNRS, Institut FOTON
UMR6082, F-3500 Rennes, France
67
Cardiff University, Cardiff CF24 3AA, UK
68
Washington State University, Pullman, WA 99164, USA
69
University of Oregon, Eugene, OR 97403, USA
70
Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-Université PSL, Collège de France, F-75005 Paris, France
71
Università degli Studi di Urbino
Carlo Bo,
I-61029 Urbino, Italy
72
INFN, Sezione di Firenze, I-50019 Sesto Fiorentino, Firenze, Italy
73
Astronomical Observatory Warsaw University, 00-478 Warsaw, Poland
74
VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
75
University of Maryland, College Park, MD 20742, USA
76
School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA
77
Université Claude Bernard Lyon 1, F-69622 Villeurbanne, France
78
Università di Napoli
Federico II,
Complesso Universitario di Monte S.Angelo, I-80126 Napoli, Italy
79
NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
80
Dipartimento di Fisica, Università degli Studi di Genova, I-16146 Genova, Italy
81
RESCEU, University of Tokyo, Tokyo, 113-0033, Japan
82
Tsinghua University, Beijing 100084, People
s Republic of China
83
Texas Tech University, Lubbock, TX 79409, USA
84
The University of Mississippi, University, MS 38677, USA
85
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Enrico Fermi
, I-00184 Roma, Italyrico Fermi, I-00184 Roma, Italy
86
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87
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91
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93
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fi
eld, 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
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98
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100
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101
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102
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103
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104
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105
MTA-ELTE Astrophysics Research Group, Institute of Physics, Eötvös University, Budapest 1117, Hungary
106
Institute for Plasma Research, Bhat, Gandhinagar 382428, India
107
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fi
eld, Shef
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108
IGFAE, Campus Sur, Universidade de Santiago de Compostela, E-15782 Spain
109
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110
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111
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112
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114
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117
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118
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125
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American University, Washington, DC 20016, USA
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,
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129
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ystok, 15-424 Bia
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140
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144
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148
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149
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150
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151
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152
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159
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fi
ques, F-91440 Bures-sur-Yvette, France
160
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161
Whitman College, 345 Boyer Avenue, Walla Walla, WA 99362 USA
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Université de Lyon, F-69361 Lyon, France
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165
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Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
Received 2019 February 9; revised 2019 March 6; accepted 2019 March 6; published 2019 April 4
Abstract
We present the results of a search for short- and intermediate-duration gravitational-wave signals from four
magnetar bursts in Advanced LIGO
s second observing run. We
fi
nd no evidence of a signal and set upper bounds
on the root sum squared of the total dimensionless strain
(
h
rss
)
from incoming intermediate-duration gravitational
waves ranging from 1.1
×
10
22
at 150 Hz to 4.4
×
10
22
at 1550 Hz at 50% detection ef
fi
ciency. From the
177
Deceased, 2018 February.
178
Deceased, 2017 November.
179
Deceased, 2018 July.
5
The Astrophysical Journal,
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)
, 2019 April 1
Abbott et al.
known distance to the magnetar SGR 1806
20
(
8.7 kpc
)
, we can place upper bounds on the isotropic
gravitational-wave energy of 3.4
×
10
44
erg at 150 Hz assuming optimal orientation. This represents an
improvement of about a factor of 10 in strain sensitivity from the previous search for such signals, conducted
during initial LIGO
s sixth science run. The short-duration search yielded upper limits of 2.1
×
10
44
erg for short
white noise bursts, and 2.3
×
10
47
erg for 100 ms long ringdowns at 1500 Hz, both at 50% detection ef
fi
ciency.
Key words:
gravitational waves
stars: magnetars
Supporting material:
data behind
fi
gures
1. Introduction
So far, the Laser Interferometer Gravitational-Wave Obser-
vatory
(
LIGO; Aasi et al.
2015
)
and Virgo
(
Acernese et al.
2015
)
have reported detections of a handful of gravitational-
wave
(
GW
)
signals from the coalescence of compact binary
systems
(
Abbott et al.
2016a
,
2016b
,
2017b
,
2017c
,
2017d
,
2017e
)
. Isolated compact objects may also emit detectable
GWs, though they are predicted to be much weaker than
compact binary coalescences
(
Sathyaprakash & Schutz
2009
)
.
Because of the high energies and mass densities required to
generate detectable GWs, neutron stars and supernovae are
among the main targets of nonbinary searches. This paper
focuses on a type of neutron star: magnetars.
Magnetars are highly magnetized isolated neutron stars
(
Woods & Thompson
2006
; Mereghetti et al.
2015
)
. Originally
classi
fi
ed as anomalous X-ray pulsars
(
AXPs
)
, or soft gamma
repeaters
(
SGRs
)
, some AXPs have been observed acting like
SGRs and vice versa. They are now considered to be a single
class of objects de
fi
ned by their power source: the star
s
magnetic
fi
eld, which, at 10
13
10
15
G, is about 100
×
stronger
than a typical neutron star. Magnetars occasionally emit short
bursts of soft
γ
-rays, but the exact mechanism responsible for
the bursts is unclear. There are currently 23 known magnetars
(
and an additional six candidates; Olausen & Kaspi
2014
)
,
180
which were identi
fi
ed based on observations across wave-
lengths of bursts, continuous pulsating emission, spindown
rates, and glitches in their rotational frequency. The bursts last
0.1 s with luminosity of up to
2
×
10
42
erg s
1
, and can
usually be localized well enough to allow identi
fi
cation of the
source magnetar. Many magnetars also emit pulsed X-rays and
some are visible in radio.
The large energies involved originally led to the belief that
magnetar bursts could be promising sources of detectable GWs,
e.g., Ioka
(
2001
)
and Corsi & Owen
(
2011
)
. Further theoretical
investigation indicates that most mechanisms are likely too
weak to be detectable by current detectors
(
Levin & van
Hoven
2011
; Zink et al.
2012
)
. Nevertheless, due to the large
amount of energy stored in their magnetic
fi
elds and known
transient activity, magnetars remain a promising source of GW
detections for ground-based detectors with rich underlying
physics.
The search presented in this paper is triggered following
the identi
fi
cation of magnetar bursts by
γ
-ray telescopes. The
methodology is similar to the one done during initial LIGO
s
sixth science run
(
Quitzow-James
2016
; Quitzow-James
et al.
2017
)
, with a few improvements and the use of an
additional pipeline targeted toward shorter duration signals
(
X-Pipeline; Sutton et al.
2010
)
. This pipeline has been used
to look for GWs coincident with
γ
-ray bursts
(
GRBs; see
Abbott et al.
2017a
for such searches during advanced
LIGO
s
fi
rst observing run
)
.
The
fi
rst searches for GW counterparts from magnetar
activity targeted the 2004 hyper
fl
are of SGR 1806
20. Initial
LIGO data were used to constrain the GW emission associated
with the quasiperiodic seismic oscillations
(
QPOs
)
of the
magnetar following this catastrophic cosmic event
(
Abbott
et al.
2007
; Matone & Márka
2007
)
as well as the instantaneous
gravitational emission
(
Kalmus et al.
2007
; Abbott et al.
2008
)
.
Abbott et al.
(
2008
)
and Abadie et al.
(
2011
)
reported on GW
emission limits associated with additional magnetar activity
observed during the initial detector era until 2009 June. LIGO
data coinciding with the 2006 SGR 1900
+
14 storm was
additionally analyzed by
stacking
GW data
(
Kalmus et al.
2009
)
corresponding to individual bursts in the storm
sEM
light curve
(
Abbott et al.
2009
)
. Additionally, a magnetar was
considered as a possible source for a GRB during initial LIGO
(
GRB 051103
)
, and a search using X-Pipeline and the Flare
pipeline placed upper limits on GW emission from the star
s
fundamental ringing mode
(
Abadie et al.
2012
)
.
The rest of this paper is laid out as follows: in Section
2
,we
provide a brief overview of the astrophysics of magnetars as is
relevant to GW astronomy and the short bursts used in this
analysis. Next, in Section
3
, we describe the methodology of
the GW search. Section
4
describes the results and upper limits
on possible gravitational radiation from the studied bursts.
Appendix
B
contains a discussion of the effect of GW
polarization on the sensitivity of the intermediate-duration
search.
2. Magnetar Bursts
Magnetars are currently not well understood. Their magnetic
fi
elds are strong and complex
(
Braithwaite & Spruit
2006
)
,and
power the star
s activity. Occasionally and unpredictably,
magnetars give off short bursts of
γ
-rays whose exact mechanism
is unknown, but may be caused by seismic events, Alfvén waves
in the star
s atmosphere, magnetic reconnection events, or some
combination of these; see, e.g., Thompson & Duncan
(
1995
)
.
After some of the brighter bursts
(
giant
fl
ares, which have been
seen only three times
)
, there is a soft X-ray tail that lasts for
hundreds of seconds. QPOs have been observed in the tail of
giant
fl
ares
(
Israel et al.
2005
;Strohmayer&Watts
2005
)
and
some short bursts
(
Huppenkothen et al.
2014a
,
2014b
)
, during
which various frequencies appear, stay for hundreds of seconds,
and then disappear again, indicating a resonance within the
magnetar. Many possible resonant modes in the core and crust of
the magnetar have been suggested to cause the QPOs, although
it is unclear which modes actually produce them. Some of
these modes, such as f-modes and r-modes, couple well to GWs,
and so, if suf
fi
ciently excited, could produce detectable GWs,
though current models indicate that they will be too weak
(
Levin & van Hoven
2011
;Zinketal.
2012
)
. Other modes, such
180
See the catalog at
http:
//
www.physics.mcgill.ca
/~
pulsar
/
magnetar
/
main.html
.
6
The Astrophysical Journal,
874:163
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)
, 2019 April 1
Abbott et al.
as the lowest order torsional mode, do not create the time-
changing quadrupole moment needed for GW emission. None
of these models provide precise predictions for emitted GW
waveforms.
This search was performed on data coincident with the four
short bursts from magnetars during advanced LIGO
s second
observing run for which there was suf
fi
cient data
(
we require
data from two detectors
)
for both short-
(
less than a second
long
)
and intermediate-duration
(
hundreds of seconds long
)
signals. Table
1
describes the four bursts. In addition to the four
studied bursts, there were
fi
ve bursts that occurred during times
when at least one detector was of
fl
ine. No GW analysis was
done on them. All GW detector data come from the two LIGO
detectors because Virgo was not taking data during any of these
bursts.
Three bursts come from the magnetar SGR 1806
20. They
were all identi
fi
ed by the Burst Alert Telescope
(
BAT
)
aboard
NASA
s
Swift
satellite
(
Gehrels et al.
2004
)
. These were
subthreshold events that were found in BAT data
(
D. M.
Palmer 2017, personal communication
)
, an example of which is
shown in Figure
1
, with the data from the other two found in
Appendix
C
. The fourth was a short GRB with a soft spectrum
observed by the
Fermi
Gamma-ray Burst Monitor
(
Atwood
et al.
2009
)
and named GRB 170304A.
3. Method
3.1. Excess Power Searches
Fundamentally, all multidetector GW searches seek to
identify GW signals that are consistent with the data collected
at both detectors. Some searches identify candidate signals in
each detector separately, then later consider only the candidates
that occur in all detectors within the light-travel time and with
the same signal parameters. This approach is disfavored in
searches that do not rely on templates. We cannot perform a
templated search here because there is no current model that
can produce templates for magnetar GW bursts. Instead, we
fi
rst combine the two data streams to create a time
frequency
map where the value in each time
frequency pixel represents
some measure of the GWs
(
often energy
)
consistent with the
observations from the detectors.
The next step is to identify GW signals in the time
frequency map. This is done by clustering together groups of
pixels, calculating the signi
fi
cance of each cluster with a
metric, and searching for the most signi
fi
cant cluster. In order
to cover a broader range of frequencies and timescales, we use
two different analysis pipelines, which use different clustering
algorithms.
The short-duration search uses seed-based clustering imple-
mented by X-Pipeline, which focuses on groups of bright
pixels
(
the seed; Sutton et al.
2010
)
. Speci
fi
cally, the clusters
considered by X-Pipeline are groups of neighboring pixels that
are all louder than a chosen threshold. This approach works
well for short-duration searches, but fails for longer duration
signals for two reasons: random noise will tend to break up the
signal into multiple clusters, and each pixel is closer to the
background, so fewer of them will be above the threshold.
We rely on STAMP
(
Thrane et al.
2011
)
for the
intermediate-duration search. STAMP offers a seedless method
whose clustering algorithm integrates over many, randomly
chosen Bézier curves
(
Thrane & Coughlin
2013
,
2014
)
.
Because of this, it can jump over gaps in clusters caused by
noise, and thus it is better suited for longer duration signals.
Additionally, it can build up the signal-to-noise ratio
(
S
/
N
)
over many pixels of only slightly elevated S
/
N. This method
was previously used to search for signals from magnetars
during initial LIGO
(
Quitzow-James
2016
; Quitzow-James
et al.
2017
)
.
3.2. X-Pipeline
X-Pipeline is a software package designed to search for
short-duration GW signals in multiple detectors and includes
automatic glitch rejection, background calculation, and soft-
ware injection processing
(
for details, see Sutton et al.
2010
)
.It
forms coherent combinations from multiple detectors, thus
making it relatively insensitive to non-GW signals, such as
instrumental artifacts. X-Pipeline is used primarily to search for
GWs coincident with GRBs, but is suitable for any short-
duration coherent search.
X-Pipeline takes a likelihood approach to estimating the GW
energy found in each time
frequency pixel. It models the data
collected at the detectors as a combination of signal and
detector noise, then uses a maximum-likelihood technique to
calculate the estimated GW signal power in each time
frequency pixel.
Table 1
List of Magnetar Bursts Considered in This GW Search
Source
Date
Time
Duration
Fluence
Distance
(
UTC
)(
s
)(
erg cm
2
)(
kpc
)
SGR 1806
20
2017 Feb 11
21:51:58
0.256
8.9
×
10
11
8.7
SGR 1806
20
2017 Feb 25
06:15:07
0.016
1.2
×
10
11
8.7
GRB 170304A
2017 Mar 4
00:04:26
0.16
3.1
×
10
10
L
SGR 1806
20
2017 Apr 29
17:00:44
0.008
1.4
×
10
11
8.7
Note.
GRB 170304A is described in GCN Circular 20813; data on the SGR 1806
20 burst activity are courtesy of David M. Palmer.
Figure 1.
Swift
BAT
s data for the February 11 burst from SGR 1806
20.
Image courtesy of David M. Palmer.
7
The Astrophysical Journal,
874:163
(
14pp
)
, 2019 April 1
Abbott et al.