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Shigeo Nagano

Bio: Shigeo Nagano is an academic researcher from National Institute of Information and Communications Technology. The author has contributed to research in topics: Gravitational wave & KAGRA. The author has an hindex of 27, co-authored 101 publications receiving 2747 citations.


Papers
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Journal ArticleDOI
Seiji Kawamura1, Hiroo Kunimori2, Mizuhiko Hosokawa2, Ryuichi Fujita3, Keiichi Maeda4, Hisa-aki Shinkai5, Takahiro Tanaka6, Yaka Wakabayashi6, Hideki Ishihara7, Kazutaka Nishiyama8, Ken-ichi Ueda9, Kaiki Taro Inoue10, Kazuhiro Yamamoto8, Kunihito Ioka, Feng-Lei Hong11, Yoshiki Tsunesada12, Kenji Numata13, Masaru Shibata6, Hitoshi Kuninaka8, Kazuhiro Hayama1, Chul-Moon Yoo6, Kazuhiro Agatsuma1, Mitsuru Musha9, Shinji Miyoki14, Yasufumi Kojima15, Yumiko Ejiri16, Takamori Akiteru14, Kentaro Somiya4, Dan Chen14, Tadayuki Takahashi8, Shiho Kobayashi17, Mitsuhiro Fukushima1, Takashi Nakamura6, Naoshi Sugiyama18, Yuta Michimura14, Yoshiyuki Obuchi1, Ayaka Shoda14, Kei Kotake1, Shihori Sakata, Takeshi Chiba19, Yoichi Aso14, Shigeo Nagano2, Tomohiro Harada20, Kiwamu Izumi14, Nobuyuki Kanda7, Isao Kawano8, Nobuki Kawashima10, Yasuo Torii1, Motohiro Enoki21, Yoshiaki Himemoto19, Hirotaka Takahashi22, Yudai Suwa6, Hisashi Hirabayashi, Hiroyuki Ito2, Keitaro Takahashi18, Kiyotomo Ichiki18, Kazuhiro Nakazawa14, Morio Toyoshima2, Takashi Hiramatsu6, Hiroyuki Nakano23, Hiroyuki Koizumi8, Ke-Xun Sun24, Toshikazu Ebisuzaki, Kent Yagi6, Takeshi Ikegami11, Koji Arai25, Kouji Nakamura1, Norio Okada1, Takeshi Takashima8, Takehiko Ishikawa8, K. Okada14, Wataru Kokuyama14, Kakeru Takahashi14, Masa-Katsu Fujimoto1, Ryuichi Takahashi26, Ryo Saito14, K. Tsubono14, Osamu Miyakawa14, Ken-ichi Oohara27, Hideyuki Horisawa28, Hideharu Ishizaki1, Shigenori Moriwaki14, Norichika Sago6, Masashi Ohkawa27, Fuminobu Takahashi14, Tatsuaki Hashimoto8, Takashi Sato27, Sachiko Kuroyanagi14, Umpei Miyamoto20, Kazuaki Kuroda14, Toshifumi Futamase29, Fumiko Kawazoe, Hideyuki Tagoshi30, Yoshinori Nakayama31, Masatake Ohashi14, Yoshiharu Eriguchi14, Toshitaka Yamazaki1, Tadashi Takano19, Hiroshi Yamakawa6, Kenta Kiuchi6, Ken-ichi Nakao7, Taiga Noumi14, Kazunori Kohri, Shinichi Nakasuka14, Wataru Hikida30, Hideo Matsuhara8, Isao Naito27, Tomotada Akutsu1, Shijun Yoshida29, Nobuyuki Matsumoto14, Masa-aki Sakagami6, Naoko Ohishi1, Ikkoh Funaki8, Hajime Sotani32, Taizoh Yoshino16, Atsushi Taruya14, Mutsuko Y. Morimoto8, E. Nishida16, Atsushi J. Nishizawa6, Hideki Asada26, Toshiyuki Morisawa6, Shinji Mukohyama14, Shuichi Sato33, Keisuke Taniguchi14, Yousuke Itoh34, Shinji Tsujikawa35, Rieko Suzuki16, Keiko Kokeyama36, Misao Sasaki6, Naoki Seto6, Koji Ishidoshiro14, Ryutaro Takahashi1, Shin-ichiro Sakai8, Hiroyuki Tashiro6, Motoyuki Saijo20, Naoko Kishimoto6, Masaki Ando6, Akitoshi Ueda1, Koh-suke Aoyanagi4, Yoshihide Kozai, Masayoshi Utashima8, Yoshito Niwa14, Jun'ichi Yokoyama14, Nobuyuki Tanaka1, Akito Araya14 

614 citations

Journal ArticleDOI
Richard J. Abbott1, T. D. Abbott2, Sheelu Abraham3, Fausto Acernese4  +1692 moreInstitutions (195)
TL;DR: In this article, the authors reported the observation of gravitational waves from two compact binary coalescences in LIGO's and Virgo's third observing run with properties consistent with neutron star-black hole (NSBH) binaries.
Abstract: We report the observation of gravitational waves from two compact binary coalescences in LIGO’s and Virgo’s third observing run with properties consistent with neutron star–black hole (NSBH) binaries. The two events are named GW200105_162426 and GW200115_042309, abbreviated as GW200105 and GW200115; the first was observed by LIGO Livingston and Virgo and the second by all three LIGO–Virgo detectors. The source of GW200105 has component masses 8.9−1.5+1.2 and 1.9−0.2+0.3M⊙ , whereas the source of GW200115 has component masses 5.7−2.1+1.8 and 1.5−0.3+0.7M⊙ (all measurements quoted at the 90% credible level). The probability that the secondary’s mass is below the maximal mass of a neutron star is 89%–96% and 87%–98%, respectively, for GW200105 and GW200115, with the ranges arising from different astrophysical assumptions. The source luminosity distances are 280−110+110 and 300−100+150Mpc , respectively. The magnitude of the primary spin of GW200105 is less than 0.23 at the 90% credible level, and its orientation is unconstrained. For GW200115, the primary spin has a negative spin projection onto the orbital angular momentum at 88% probability. We are unable to constrain the spin or tidal deformation of the secondary component for either event. We infer an NSBH merger rate density of 45−33+75Gpc−3yr−1 when assuming that GW200105 and GW200115 are representative of the NSBH population or 130−69+112Gpc−3yr−1 under the assumption of a broader distribution of component masses.

374 citations

Journal ArticleDOI
Seiji Kawamura1, Masaki Ando2, Takashi Nakamura3, K. Tsubono2, Takahiro Tanaka3, I. Funaki, Naoki Seto1, Kenji Numata4, Shuichi Sato1, Kunihito Ioka, Nobuyuki Kanda5, T. Takashima, Kazuhiro Agatsuma2, Tomotada Akutsu2, Koh-suke Aoyanagi6, Koji Arai1, Y. Arase2, Akito Araya2, Hideki Asada7, Yoichi Aso8, Takeshi Chiba9, Toshikazu Ebisuzaki, Motohiro Enoki10, Yoshiharu Eriguchi2, Masa-Katsu Fujimoto1, Ryuichi Fujita11, Mitsuhiro Fukushima1, Toshifumi Futamase12, Katsuhiko Ganzu3, Tomohiro Harada13, Tatsuaki Hashimoto, Kazuhiro Hayama14, Wataru Hikida11, Yoshiaki Himemoto15, Hisashi Hirabayashi16, Takashi Hiramatsu2, Feng-Lei Hong17, Hideyuki Horisawa18, Mizuhiko Hosokawa19, Kiyotomo Ichiki2, Takeshi Ikegami17, Kaiki Taro Inoue20, Koji Ishidoshiro2, Hideki Ishihara5, Takehiko Ishikawa, Hideharu Ishizaki1, Hiroyuki Ito19, Yousuke Itoh21, S. Kamagasako2, Nobuki Kawashima20, Fumiko Kawazoe22, Hiroyuki Kirihara2, Naoko Kishimoto, Kenta Kiuchi6, Shiho Kobayashi23, Kazunori Kohri24, Hiroyuki Koizumi2, Yasufumi Kojima25, Keiko Kokeyama22, Wataru Kokuyama2, Kei Kotake1, Yoshihide Kozai, Hideaki Kudoh2, Hiroo Kunimori19, H. Kuninaka, Kazuaki Kuroda2, Keiichi Maeda6, Hideo Matsuhara, Yasushi Mino26, Osamu Miyakawa26, Shinji Miyoki2, Mutsuko Y. Morimoto, T. Morioka2, Toshiyuki Morisawa3, Shigenori Moriwaki2, Shinji Mukohyama2, Mitsuru Musha27, Shigeo Nagano19, Isao Naito, N. Nakagawa2, Kouji Nakamura1, Hiroyuki Nakano28, Ken-ichi Nakao5, Shinichi Nakasuka2, Yoshinori Nakayama29, E. Nishida22, Kazutaka Nishiyama, Atsushi J. Nishizawa3, Yoshito Niwa3, Masatake Ohashi2, Naoko Ohishi1, Masashi Ohkawa30, Akira Okutomi2, Kouji Onozato2, K. Oohara30, Norichika Sago31, Motoyuki Saijo31, Masa-aki Sakagami3, Shin-ichiro Sakai, Shihori Sakata22, Misao Sasaki3, Takashi Sato30, Masaru Shibata2, Hisa-aki Shinkai32, Kentaro Somiya33, Hajime Sotani34, Naoshi Sugiyama35, Yudai Suwa2, Hideyuki Tagoshi11, Kakeru Takahashi2, Tadayuki Takahashi, Hirotaka Takahashi36, Ryuichi Takahashi35, Akiteru Takamori2, Tetsushi Takano, Keisuke Taniguchi37, Atsushi Taruya2, Hiroyuki Tashiro3, M. Tokuda5, Masao Tokunari2, Morio Toyoshima19, Shinji Tsujikawa, Yoshiki Tsunesada38, Ken-ichi Ueda27, Masayoshi Utashima16, Hiroshi Yamakawa3, Kazuhiro Yamamoto1, Toshitaka Yamazaki1, Jun'ichi Yokoyama2, Chul-Moon Yoo3, Shijun Yoshida12, Taizoh Yoshino 
TL;DR: DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) as discussed by the authors is the future Japanese space gravitational wave antenna, which aims at detecting various kinds of gravitational waves between 1 mHz and 100 Hz frequently enough to open a new window of observation for gravitational wave astronomy.
Abstract: DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. It aims at detecting various kinds of gravitational waves between 1 mHz and 100 Hz frequently enough to open a new window of observation for gravitational wave astronomy. The pre-conceptual design of DECIGO consists of three drag-free satellites, 1000 km apart from each other, whose relative displacements are measured by a Fabry–Perot Michelson interferometer. We plan to launch DECIGO in 2024 after a long and intense development phase, including two pathfinder missions for verification of required technologies.

342 citations

Journal ArticleDOI
Tomotada Akutsu1, Masaki Ando1, Masaki Ando2, Koya Arai2  +199 moreInstitutions (48)
TL;DR: KAGRA as discussed by the authors is a 2.5-generation GW detector with two 3'km baseline arms arranged in an 'L' shape, similar to the second generations of Advanced LIGO and Advanced Virgo, but it will be operating at cryogenic temperatures with sapphire mirrors.
Abstract: The recent detections of gravitational waves (GWs) reported by the LIGO and Virgo collaborations have made a significant impact on physics and astronomy. A global network of GW detectors will play a key role in uncovering the unknown nature of the sources in coordinated observations with astronomical telescopes and detectors. Here we introduce KAGRA, a new GW detector with two 3 km baseline arms arranged in an ‘L’ shape. KAGRA’s design is similar to the second generations of Advanced LIGO and Advanced Virgo, but it will be operating at cryogenic temperatures with sapphire mirrors. This low-temperature feature is advantageous for improving the sensitivity around 100 Hz and is considered to be an important feature for the third-generation GW detector concept (for example, the Einstein Telescope of Europe or the Cosmic Explorer of the United States). Hence, KAGRA is often called a 2.5-generation GW detector based on laser interferometry. KAGRA’s first observation run is scheduled in late 2019, aiming to join the third observation run of the advanced LIGO–Virgo network. When operating along with the existing GW detectors, KAGRA will be helpful in locating GW sources more accurately and determining the source parameters with higher precision, providing information for follow-up observations of GW trigger candidates.

298 citations

Journal ArticleDOI
TL;DR: The Large-scale Cryogenic Gravitational wave Telescope (KAGRA) as discussed by the authors is a 2.5-generation GW detector with two 3-km baseline arms arranged in the shape of an "L", located inside the Mt. Ikenoyama, Kamioka, Gifu, Japan.
Abstract: The recent detections of gravitational waves (GWs) reported by LIGO/Virgo collaborations have made significant impact on physics and astronomy. A global network of GW detectors will play a key role to solve the unknown nature of the sources in coordinated observations with astronomical telescopes and detectors. Here we introduce KAGRA (former name LCGT; Large-scale Cryogenic Gravitational wave Telescope), a new GW detector with two 3-km baseline arms arranged in the shape of an "L", located inside the Mt. Ikenoyama, Kamioka, Gifu, Japan. KAGRA's design is similar to those of the second generations such as Advanced LIGO/Virgo, but it will be operating at the cryogenic temperature with sapphire mirrors. This low temperature feature is advantageous for improving the sensitivity around 100 Hz and is considered as an important feature for the third generation GW detector concept (e.g. Einstein Telescope of Europe or Cosmic Explorer of USA). Hence, KAGRA is often called as a 2.5 generation GW detector based on laser interferometry. The installation and commissioning of KAGRA is underway and its cryogenic systems have been successfully tested in May, 2018. KAGRA's first observation run is scheduled in late 2019, aiming to join the third observation run (O3) of the advanced LIGO/Virgo network. In this work, we describe a brief history of KAGRA and highlights of main feature. We also discuss the prospects of GW observation with KAGRA in the era of O3. When operating along with the existing GW detectors, KAGRA will be helpful to locate a GW source more accurately and to determine the source parameters with higher precision, providing information for follow-up observations of a GW trigger candidate.

254 citations


Cited by
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Journal ArticleDOI
01 Apr 1988-Nature
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

9,929 citations

Journal Article
TL;DR: The first direct detection of gravitational waves and the first observation of a binary black hole merger were reported in this paper, with a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ.
Abstract: On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160) Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

4,375 citations

Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott, T. D. Abbott, Sheelu Abraham  +1145 moreInstitutions (8)
TL;DR: In this paper, the authors presented the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1 Ma during the first and second observing runs of the advanced GW detector network.
Abstract: We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1 Ma™ during the first and second observing runs of the advanced gravitational-wave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole mergers, four of which we report here for the first time: GW170729, GW170809, GW170818, and GW170823. For all significant gravitational-wave events, we provide estimates of the source properties. The detected binary black holes have total masses between 18.6-0.7+3.2 Mâ™ and 84.4-11.1+15.8 Mâ™ and range in distance between 320-110+120 and 2840-1360+1400 Mpc. No neutron star-black hole mergers were detected. In addition to highly significant gravitational-wave events, we also provide a list of marginal event candidates with an estimated false-alarm rate less than 1 per 30 days. From these results over the first two observing runs, which include approximately one gravitational-wave detection per 15 days of data searched, we infer merger rates at the 90% confidence intervals of 110-3840 Gpc-3 y-1 for binary neutron stars and 9.7-101 Gpc-3 y-1 for binary black holes assuming fixed population distributions and determine a neutron star-black hole merger rate 90% upper limit of 610 Gpc-3 y-1.

2,336 citations