Updated on 2026/01/17

写真a

 
HAYATSU, Natsuki
 
Affiliation
Faculty of Science and Engineering, Waseda Research Institute for Science and Engineering
Job title
Junior Researcher(Assistant Professor)

Research Experience

  • 2025.04
    -
    Now

    Waseda University   Faculty of Science and Engineering   Junior Researcher(Assistant Professor)

  • 2022.09
    -
    2025.03

    National Astronomical Observatory of Japan   Public Relations Center Ishigakijima Astronomical Observatory   NAOJ Project Research Felow

  • 2022.05
    -
    2022.08

    European Southern Observatory   Visiting Researcher

  • 2020.09
    -
    2022.08

    パリ高等師範学校   プロジェクト研究員

    Host researcher: Edith Falgarone

  • 2020.04
    -
    2021.03

    National Astronomical Observatory of Japan

  • 2020.06
    -
    2020.08

    Bunkyo University

  • 2017.10
    -
    2019.03

    Europian Southern Observatory

    Host Researcher: Rob Ivison, Paola Andreani

  • 2017.02
    　
    　

    National Astronomical Observatory of Japan

  • 2016.02
    　
    　

    Durham University   Visiting Student

    Host Researcher: Ian Smail, three weeks

  • 2015.08
    　
    　

    National Astronomical Observatory of Japan   Visiting Fellow

  • 2012.03
    　
    　

    National Astronomical Observatory of Japan   visiting fellow

▼display all

Education Background

  • 2015.04
    -
    2020.03

    The University of Tokyo   Graduate School of Science   Department of Physics (Ph.D.)  

  • 2012.04
    -
    2015.03

    The University of Tokyo   Graduate School of Science   Department of Physics  

  • 2008.04
    -
    2012.03

    Nihon University   College of Science and Technology   Department of Physics  

  • 2004.04
    -
    2007.03

    Tokyo Metropilitan Toyama High School  

Committee Memberships

  • 2025.01
    -
    2026.03

    Workshop "Star Forming Galaxies in the Reionization Epoch: ALMA-Driven Studies with the Aid of JWST"  Organiser (SOC, LOC)

  • 2014.01
    -
    2014.07

    天文・天体物理若手の会  LOC（会場係 係長）、SOC

Professional Memberships

  • 2015.12
    -
    Now

    日本天文学会

Research Areas

  • Astronomy   遠赤外線銀河、輝線銀河、宇宙星形成史、銀河形成

Research Interests

  • Far-infrared line emitter (galaxy)

  • Galaxy Evolution

  • Cosmic Star-Formation HIstory

Awards

  • NAOJ Director General's Award

    2024.01   National Astronomical Observatory of Japan   Stable Operations through Regional Collaboration and Continued Contributions to Public Relations, Education, and Scientific Research

 

Papers

  • Serendipitous discovery of an optically dark ultra-luminous infrared galaxy at z = 3.4

    Natsuki H Hayatsu, Zhi-Yu Zhang, R J Ivison, Chao-Wei Tsai, Ping Zhou, Katsuya Okoshi, Chentao Yang, Yuri Nishimura, Kotaro Kohno, Nobunari Kashikawa, Masahiro Nagashima, Junfeng Wang, Denis Burgarella

    Monthly Notices of the Royal Astronomical Society    2025.10

    　View Summary

    Dusty, submillimeter-selected galaxies without optical counterparts contribute a non-negligible fraction of the star formation in the early universe. However, such a population is difficult to detect through classical optical/UV-based surveys. We report the serendipitous discovery of such an optically dark galaxy, behind the quadruply-lensed $z=2.56$ quasar, H1413+117, offset to the north by 6\arcsec. From $^{12}$CO $J=4$--3, $J=6$--5, and part of the $J=13$--12 transitions, which all spatially coincide with a compact submillimeter continuum emission, we determine an unambiguous spectroscopic redshift, $z=3.386\pm 0.005$. This galaxy has a molecular mass $M_{\rm mol} \sim 10^{11}$ M$_\odot$ and a black hole mass $M_{\rm BH} \sim 10^{8}$ M$_\odot$, estimated from $^{12}$CO $J=4$--3 and archival {\it Chandra} X-ray data ($L_{\rm 2-10,keV} \sim 4 \times 10^{44}$\,erg\,s$^{-1}$), respectively. We also estimate a total infrared luminosity of $L_{\rm FIR} = (2.8\pm{2.3}) \times 10^{12}$ L$_\odot$ and a stellar mass of $M_* \lesssim 10^{11}$ M$_{\odot}$, from spectral energy distribution fitting. According to these simple mass estimations, this gas-rich and X-ray bright galaxy might be in a transition phase from starburst to quasar offering a unique case for studying galaxy-black hole co-evolution under extremely dusty conditions.

    DOI

    Scopus

  • ALMA deep field in SSA22: Reconstructed [C II] luminosity function at z = 6

    Hayatsu, Natsuki H, Ivison, Rob J, Andreani, Paola, Guglielmetti, Fabrizia, Zhang, Zhi-Yu, Biggs, Andy, Umehata, Hideki, Matsuda, Yuichi, Yoshida, Naoki, Swinbank, Mark A, Kohno, Kotaro, Tamura, Yoichi, Hatsukade, Bunyo, Nakanishi, Kouichiro, Ao, Yiping, Nagao, Tohru, Kubo, Mariko, Takeuchi, Tsutomu T, Lee, Minju, Izumi, Takuma, Ikarashi, Soh, Yamada, Tohru

    \pasj    2024.10

    DOI

    Scopus

  • FIR-luminous [C II] Emitters in the ALMA-SCUBA-2 COSMOS Survey (AS2COSMOS): The Nature of Submillimeter Galaxies in a 10 Comoving Megaparsec-scale Structure at z \ensuremath∼ 4.6

    Mitsuhashi, I., Matsuda, Y., Smail, Ian, Hayatsu, N.~H., Simpson, J.~M., Swinbank, A.~M., Umehata, H., Dudzevičiūtė, U., Birkin, J.~E., Ikarashi, S., Chen, Chian-Chou, Tadaki, K., Yajima, H., Harikane, Y., Inami, H., Chapman, S.~C., Hatsukade, B., Iono, D., Bunker, A., Ao, Y., Saito, T., Ueda, J., Sakamoto, S.

    \apj   907 ( 2 ) 122 - 122  2021.02

    　View Summary

    We report the discovery of a 10 comoving Mpc-scale structure traced by massive submillimeter galaxies (SMGs) at z~4.6. These galaxies are selected from an emission line search of ALMA Band 7 observations targeting 184 luminous submillimeter sources ($S_{850μ{\rm m } }\geq$ 6.2 mJy) across 1.6 degrees$^2$ in the COSMOS field. We identify four [CII] emitting SMGs and two probable [CII] emitting SMG candidates at z=4.60-4.64 with velocity-integrated signal-to-noise ratio of SNR>8. Four of the six emitters are near-infrared blank SMGs. After excluding one SMG whose emission line is falling at the edge of the spectral window, all galaxies show clear velocity gradients along the major axes that are consistent with rotating gas disks. The estimated rotation velocities of the disks are 330-550 km s$^{-1}$ and the inferred host dark-matter halo masses are ~2-8 $\times$ 10$^{12}$M$_{\odot}$. From their estimated halo masses and [CII] luminosity function, we suggest that these galaxies have a high (50-100%) duty cycle and high (~0.1) baryon conversion efficiency (SFR relative to baryon accretion rate), and that they contribute $\simeq$2% to the total star-formation rate density at z=4.6. These SMGs are concentrated within just 0.3% of the full survey volume, suggesting they are strongly clustered. The extent of this structure and the individual halo masses suggest that these SMGs will likely evolve into members of a ~10$^{15}$M$_{\odot}$ cluster at z=0. This survey reveals synchronized dusty starburst in massive halos at z>4, which could be driven by mergers or fed by smooth gas accretion.

    DOI

    Scopus

    17
    Citation
    (Scopus)

  • ALMA Deep Field in SSA22. A near-infrared-dark submillimeter galaxy at z = 4.0

    Umehata, Hideki, Smail, Ian, Swinbank, A.~M., Kohno, Kotaro, Tamura, Yoichi, Wang, Tao, Ao, Yiping, Hatsukade, Bunyo, Kubo, Mariko, Nakanishi, Kouchiro, Hayatsu, Natsuki N.

    åp    2020.08

    DOI

    Scopus

    28
    Citation
    (Scopus)

  • ALMA twenty-six arcmin$^2$ survey of GOODS-S at one millimeter (ASAGAO): Millimeter properties of stellar mass selected galaxies

    Yamaguchi, Yuki, Kohno, Kotaro, Hatsukade, Bunyo, Wang, Tao, Yoshimura, Yuki, Ao, Yiping, Dunlop, James S., Egami, Eiichi, Espada, Daniel, Fujimoto, Seiji, Hayatsu, Natsuki H., Ivison, Rob J., Kodama, Tadayuki, Kusakabe, Haruka, Nagao, Tohru, Ouchi, Masami, Rujopakarn, Wiphu, Tadaki, Ken-ichi, Tamura, Yoichi, Ueda, Yoshihiro, Umehata, Hideki, Wang, Wei-Hao

    \pasj   72 ( 4 ) 69 - 69  2020.08

    DOI

    Scopus

    6
    Citation
    (Scopus)

  • The correct estimate of the probability of false detection of the matched filter in weak-signal detection problems. III. Peak distribution method versus the Gumbel distribution method

    Vio, R., Andreani, P., Biggs, A., Hayatsu, N.

    åp    2019.07

    DOI

    Scopus

    8
    Citation
    (Scopus)

  • ADF22: Blind Detections of [C\,II] Line Emitters Shown to be Spurious

    Hayatsu, Natsuki H., Ivison, R.~J., Andreani, Paola, Umehata, Hideki, Matsuda, Yuichi, Yoshida, Naoki, Kohno, Kotaro, Hatsukade, Bunyo, Inoue, Akio K., Tamura, Yoichi, Takeuchi, Tutomu T., Fujimoto, Seiji, Lee, Minju M., Nagao, Tohru, Ao, Yiping

    Research Notes of the American Astronomical Society   3 ( 7 ) 97 - 97  2019.07

    　View Summary

    We report Atacama Large Millimetre/submillimeter Array (ALMA) Cycle-5 follow-up observations of two candidate [CII] emitters at z ~ 6 in the ALMA deep field in SSA22 (ADF22). The candidates were detected blindly in a Cycle-2 ALMA survey covering ~ 5 square arcmins, with a single tuning, along with two CO lines associated with galaxies at lower redshifts. Various tests suggested at least one of the two > 6-sigma [CII] candidates should be robust (Hayatsu et al. 2017). Nevertheless, our new, deeper observations recover neither candidate, demonstrating a higher contamination rate than expected. The cause of the spurious detections is under investigation but at present it remains unclarified.

    DOI

  • ALMA 26 arcmin$^2$ Survey of GOODS-S at 1 mm (ASAGAO): Near-infrared-dark Faint ALMA Sources

    Yamaguchi, Yuki, Kohno, Kotaro, Hatsukade, Bunyo, Wang, Tao, Yoshimura, Yuki, Ao, Yiping, Caputi, Karina I., Dunlop, James S., Egami, Eiichi, Espada, Daniel, Fujimoto, Seiji, Hayatsu, Natsuki H., Ivison, Rob J., Kodama, Tadayuki, Kusakabe, Haruka, Nagao, Tohru, Ouchi, Masami, Rujopakarn, Wiphu, Tadaki, Ken-ichi, Tamura, Yoichi, Ueda, Yoshihiro, Umehata, Hideki, Wang, Wei-Hao, Yun, Min S.

    \apj   878 ( 1 ) 73 - 73  2019.06

    DOI

    Scopus

    63
    Citation
    (Scopus)

  • ALMA twenty-six arcmin$^2$ survey of GOODS-S at one millimeter (ASAGAO): Source catalog and number counts

    Hatsukade, Bunyo, Kohno, Kotaro, Yamaguchi, Yuki, Umehata, Hideki, Ao, Yiping, Aretxaga, Itziar, Caputi, Karina I., Dunlop, James S., Egami, Eiichi, Espada, Daniel, Fujimoto, Seiji, Hayatsu, Natsuki H., Hughes, David H., Ikarashi, Soh, Iono, Daisuke, Ivison, Rob J., Kawabe, Ryohei, Kodama, Tadayuki, Lee, Minju, Matsuda, Yuichi, Nakanishi, Kouichiro, Ohta, Kouji, Ouchi, Masami, Rujopakarn, Wiphu, Suzuki, Tomoko, Tamura, Yoichi, Ueda, Yoshihiro, Wang, Tao, Wang, Wei-Hao, Wilson, Grant W., Yoshimura, Yuki, Yun, Min S.

    \pasj   70 ( 6 ) 105 - 105  2018.12

    DOI

    Scopus

    37
    Citation
    (Scopus)

  • ALMA deep field in SSA22: Survey design and source catalog of a 20 arcmin$^2$ survey at 1.1 mm

    Umehata, Hideki, Hatsukade, Bunyo, Smail, Ian, Alexander, David M., Ivison, Rob J., Matsuda, Yuichi, Tamura, Yoichi, Kohno, Kotaro, Kato, Yuta, Hayatsu, Natsuki H., Kubo, Mariko, Ikarashi, Soh

    \pasj   70 ( 4 ) 65 - 65  2018.08

    DOI

    Scopus

    32
    Citation
    (Scopus)

  • The onset of star formation 250 million years after the Big Bang

    Hashimoto, Takuya, Laporte, Nicolas, Mawatari, Ken, Ellis, Richard S., Inoue, Akio K., Zackrisson, Erik, Roberts-Borsani, Guido, Zheng, Wei, Tamura, Yoichi, Bauer, Franz E., Fletcher, Thomas, Harikane, Yuichi, Hatsukade, Bunyo, Hayatsu, Natsuki H., Matsuda, Yuichi, Matsuo, Hiroshi, Okamoto, Takashi, Ouchi, Masami, Pelló, Roser, Rydberg, Claes-Erik, Shimizu, Ikkoh, Taniguchi, Yoshiaki, Umehata, Hideki, Yoshida, Naoki

    \nat   557 ( 7705 )  2018.05

    DOI

    Scopus

    305
    Citation
    (Scopus)

  • ALMA 26 arcmin$^2$ Survey of GOODS-S at One-millimeter (ASAGAO): X-Ray AGN Properties of Millimeter-selected Galaxies

    Ueda, Y., Hatsukade, B., Kohno, K., Yamaguchi, Y., Tamura, Y., Umehata, H., Akiyama, M., Ao, Y., Aretxaga, I., Caputi, K., Dunlop, J.~S., Espada, D., Fujimoto, S., Hayatsu, N.~H., Imanishi, M., Inoue, A.~K., Ivison, R.~J., Kodama, T., Lee, M.~M., Matsuoka, K., Miyaji, T., Morokuma-Matsui, K., Nagao, T., Nakanishi, K., Nyland, K., Ohta, K., Ouchi, M., Rujopakarn, W., Saito, T., Tadaki, K., Tanaka, I., Taniguchi, Y., Wang, T., Wang, W.-H., Yoshimura, Y., Yun, M.~S.

    \apj   853 ( 1 ) 24 - 24  2018.01

    DOI

    Scopus

    36
    Citation
    (Scopus)

  • Blind Millimeter Line Emitter Search using ALMA Data Toward Gravitational Lensing Clusters

    Yamaguchi, Yuki, Kohno, Kotaro, Tamura, Yoichi, Oguri, Masamune, Ezawa, Hajime, Hayatsu, Natsuki H., Kitayama, Tetsu, Matsuda, Yuichi, Matsuo, Hiroshi, Oshima, Tai, Ota, Naomi, Izumi, Takuma, Umehata, Hideki

    \apj   845 ( 2 ) 108 - 108  2017.08

    DOI

    Scopus

    19
    Citation
    (Scopus)

  • ALMA deep field in SSA22: Blindly detected CO emitters and [C II] emitter candidates

    Hayatsu, Natsuki H., Matsuda, Yuichi, Umehata, Hideki, Yoshida, Naoki, Smail, Ian, Swinbank, A. Mark, Ivison, Rob, Kohno, Kotaro, Tamura, Yoichi, Kubo, Mariko, Iono, Daisuke, Hatsukade, Bunyo, Nakanishi, Kouichiro, Kawabe, Ryohei, Nagao, Tohru, Inoue, Akio K., Takeuchi, Tsutomu T., Lee, Minju, Ao, Yiping, Fujimoto, Seiji, Izumi, Takuma, Yamaguchi, Yuki, Ikarashi, Soh, Yamada, Toru

    \pasj   69 ( 3 ) 45 - 45  2017.06

    DOI

    Scopus

    24
    Citation
    (Scopus)

▼display all

Books and Other Publications

Misc

  • LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration

    Morokuma, Tomoki, Tominaga, Nozomu, Yanagisawa, Kenshi, Tanaka, Ichi, Yoshida, Michitoshi, Matsubayashi, Kazuya, Akitaya, Hiroshi, Hamada, Ryusei, Suzuki, Daisuke, Higuchi, Narikazu, Sasada, Mahito, Seki, Hibiki, Takahashi, Ichiro, Joshima, Shigeaki, Hagio, Haruna, Kubo, Yoshiyuki, Honda, Satoshi, Takahashi, Jun, Ohshima, Tomohito, Kawabata, Koji, Nakaoka, Tatsuya, Itoh, Ryosuke, Kokubo, Mitsuru, Hayatsu, Natsuki, Hanayama, Hidekazu, Kanai, Takahiro, Oasa, Yumiko, Murata, Katsuhiro L., Taguchi, Kenta, Ohta, Kouji, Kawabata, Miho, Maeda, Keiichi, Kusune, Takayoshi, Niino, Yuu, Sekiguchi, Yuichiro, Tanaka, Masaomi, Utsumi, Yousuke, Japanese Collaboration for Gravitational-Wave Electro-Magnetic Follow-up Collaboration

    GRB Coordinates Network   36302   1 - 1  2024.04

  • LIGO/Virgo/KAGRA S240422ed: A transient discovered from Subaru/MOIRCS near-infrared observations by J-GEM Collaboration

    Takahashi, Ichiro, Higuchi, Narikazu, Sasada, Mahito, Morokuma, Tomoki, Tominaga, Nozomu, Yanagisawa, Kenshi, Tanaka, Ichi, Yoshida, Michitoshi, Matsubayashi, Kazuya, Akitaya, Hiroshi, Hamada, Ryusei, Suzuki, Daisuke, Seki, Hibiki, Joshima, Shigeaki, Hagio, Haruna, Kubo, Yoshiyuki, Honda, Satoshi, Takahashi, Jun, Ohshima, Tomohito, Kawabata, Koji, Nakaoka, Tatsuya, Itoh, Ryosuke, Kokubo, Mitsuru, Hayatsu, Natsuki, Hanayama, Hidekazu, Kanai, Takahiro, Oasa, Yumiko, Murata, Katsuhiro L., Taguchi, Kenta, Ohta, Kouji, Kawabata, Miho, Maeda, Keiichi, Kusune, Takayoshi, Niino, Yuu, Sekiguchi, Yuichiro, Tanaka, Masaomi, Utsumi, Yousuke, Japanese Collaboration for Gravitational-Wave Electro-Magnetic Follow-up, Collaboration

    GRB Coordinates Network   36333   1 - 1  2024.04

  • GRB 230723B: MITSuME Ishigaki optical observation

    Hayatsu, N.~H., Hanayama, H., Sasada, M., Takahashi, I., Niwano, M., Sato, S., Hayatsu, S., Higuchi, N., Takei, H., Seki, H., Yatsu, Y., Murata, K.~L., Kawai, N., MITSuME Collaboration

    GRB Coordinates Network   34295   1 - 1  2023.07

 

Syllabus

Teaching Experience

 

Social Activities

Sub-affiliation

  • Faculty of Science and Engineering   School of Advanced Science and Engineering