The Astrophysical Journal (Jan 2023)
EMPRESS. IX. Extremely Metal-poor Galaxies are Very Gas-rich Dispersion-dominated Systems: Will the James Webb Space Telescope Witness Gaseous Turbulent High-z Primordial Galaxies?
- Yuki Isobe,
- Masami Ouchi,
- Kimihiko Nakajima,
- Shinobu Ozaki,
- Nicolas F. Bouché,
- John H. Wise,
- Yi Xu,
- Eric Emsellem,
- Haruka Kusakabe,
- Takashi Hattori,
- Tohru Nagao,
- Gen Chiaki,
- Hajime Fukushima,
- Yuichi Harikane,
- Kohei Hayashi,
- Yutaka Hirai,
- Ji Hoon Kim,
- Michael V. Maseda,
- Kentaro Nagamine,
- Takatoshi Shibuya,
- Yuma Sugahara,
- Hidenobu Yajima,
- Shohei Aoyama,
- Seiji Fujimoto,
- Keita Fukushima,
- Shun Hatano,
- Akio K. Inoue,
- Tsuyoshi Ishigaki,
- Masahiro Kawasaki,
- Takashi Kojima,
- Yutaka Komiyama,
- Shuhei Koyama,
- Yusei Koyama,
- Chien-Hsiu Lee,
- Akinori Matsumoto,
- Ken Mawatari,
- Takashi J. Moriya,
- Kentaro Motohara,
- Kai Murai,
- Moka Nishigaki,
- Masato Onodera,
- Yoshiaki Ono,
- Michael Rauch,
- Tomoki Saito,
- Rin Sasaki,
- Akihiro Suzuki,
- Tsutomu T. Takeuchi,
- Hiroya Umeda,
- Masayuki Umemura,
- Kuria Watanabe,
- Kiyoto Yabe,
- Yechi Zhang
Affiliations
- Yuki Isobe
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Department of Physics, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- Masami Ouchi
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo , Kashiwa, Chiba 277-8583, Japan
- Kimihiko Nakajima
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Shinobu Ozaki
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Nicolas F. Bouché
- ORCiD
- Univ Lyon , Univ Lyon1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval France
- John H. Wise
- ORCiD
- Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology , Atlanta, GA 30332, USA
- Yi Xu
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Department of Astronomy, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- Eric Emsellem
- ORCiD
- Univ Lyon , Univ Lyon1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval France; European Southern Observatory , Karl-Schwarzschild-Straße 2, D-85748 Garching, Germany
- Haruka Kusakabe
- ORCiD
- Observatoire de Genéve, Université de Genéve , 51 Ch. des Maillettes, 1290 Versoix, Switzerland
- Takashi Hattori
- ORCiD
- Subaru Telescope, National Astronomical Observatory of Japan , National Institutes of Natural Sciences (NINS), 650 North A’ohoku Place, Hilo, HI 96720, USA
- Tohru Nagao
- ORCiD
- Research Center for Space and Cosmic Evolution, Ehime University , Bunkyo-cho 2–5, Matsuyama, Ehime 790-8577, Japan
- Gen Chiaki
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Hajime Fukushima
- ORCiD
- Center for Computational Sciences, University of Tsukuba , Ten-nodai, 1-1-1 Tsukuba, Ibaraki 305-8577, Japan
- Yuichi Harikane
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Department of Physics and Astronomy, University College London , Gower Street, London WC1E 6BT, UK
- Kohei Hayashi
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; National Institute of Technology , Ichinoseki College, Hagisho, Ichinoseki, 021-8511, Japan; Astronomical Institute, Tohoku University , 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan
- Yutaka Hirai
- ORCiD
- Astronomical Institute, Tohoku University , 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan; Department of Physics and Astronomy, University of Notre Dame , 225 Nieuwland Science Hall, Notre Dame, IN 46556, USA
- Ji Hoon Kim
- ORCiD
- Astronomy Program, Department of Physics and Astronomy, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea; SNU Astronomy Research Center, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
- Michael V. Maseda
- ORCiD
- Department of Astronomy, University of Wisconsin-Madison , 475 N. Charter Street, Madison, WI 53706, USA
- Kentaro Nagamine
- ORCiD
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo , Kashiwa, Chiba 277-8583, Japan; Theoretical Astrophysics, Department of Earth & Space Science, Graduate School of Science, Osaka University , 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Physics & Astronomy, University of Nevada , Las Vegas, 4505 S. Maryland Parkway, Las Vegas, NV 89154-4002, USA
- Takatoshi Shibuya
- Kitami Institute of Technology , 165 Koen-cho, Kitami, Hokkaido 090-8507, Japan
- Yuma Sugahara
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Waseda Research Institute for Science and Engineering, Faculty of Science and Engineering, Waseda University , 3-4-1, Okubo, Shinjuku, Tokyo 169-8555, Japan
- Hidenobu Yajima
- ORCiD
- Center for Computational Sciences, University of Tsukuba , Ten-nodai, 1-1-1 Tsukuba, Ibaraki 305-8577, Japan
- Shohei Aoyama
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Institute of Management and Information Technologies, Chiba University , 1-33, Yayoi-cho, Inage-ward, Chiba, 263-8522, Japan
- Seiji Fujimoto
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Cosmic DAWN Center , Denmark; Niels Bohr Institute, University of Copenhagen , Lyngbyvej2, DK-2100, Copenhagen, Denmark; Research Institute for Science and Engineering, Waseda University , 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
- Keita Fukushima
- Theoretical Astrophysics, Department of Earth & Space Science, Graduate School of Science, Osaka University , 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
- Shun Hatano
- ORCiD
- Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies) , Osawa 2-21-1, Mitaka, Tokyo, 181-8588, Japan
- Akio K. Inoue
- ORCiD
- Waseda Research Institute for Science and Engineering, Faculty of Science and Engineering, Waseda University , 3-4-1, Okubo, Shinjuku, Tokyo 169-8555, Japan; Department of Physics, School of Advanced Science and Engineering, Faculty of Science and Engineering, Waseda University , 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
- Tsuyoshi Ishigaki
- Department of Physical Science and Materials Engineering, Faculty of Science and Engineering, Iwate University 3-18-34 Ueda , Morioka, Iwate 020-8550, Japan
- Masahiro Kawasaki
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo , Kashiwa, Chiba 277-8583, Japan
- Takashi Kojima
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Department of Physics, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- Yutaka Komiyama
- ORCiD
- Department of Advanced Sciences, Faculty of Science and Engineering, Hosei University , 3-7-2 Kajino-cho, Koganei-shi, Tokyo 184-8584, Japan
- Shuhei Koyama
- Institute of Astronomy, Graduate School of Science, The University of Tokyo , 2-21-1 Osawa, Mitaka, Tokyo 181-0015, Japan
- Yusei Koyama
- ORCiD
- Subaru Telescope, National Astronomical Observatory of Japan , National Institutes of Natural Sciences (NINS), 650 North A’ohoku Place, Hilo, HI 96720, USA; Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies) , Osawa 2-21-1, Mitaka, Tokyo, 181-8588, Japan
- Chien-Hsiu Lee
- ORCiD
- W.M. Keck Observatory , Kamuela, HI 96743, USA
- Akinori Matsumoto
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Department of Physics, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- Ken Mawatari
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
- Takashi J. Moriya
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; School of Physics and Astronomy, Faculty of Science, Monash University , Clayton, Victoria 3800, Australia
- Kentaro Motohara
- ORCiD
- National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Institute of Astronomy, Graduate School of Science, The University of Tokyo , 2-21-1 Osawa, Mitaka, Tokyo 181-0015, Japan
- Kai Murai
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]
- Moka Nishigaki
- ORCiD
- Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies) , Osawa 2-21-1, Mitaka, Tokyo, 181-8588, Japan
- Masato Onodera
- ORCiD
- Subaru Telescope, National Astronomical Observatory of Japan , National Institutes of Natural Sciences (NINS), 650 North A’ohoku Place, Hilo, HI 96720, USA; Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies) , Osawa 2-21-1, Mitaka, Tokyo, 181-8588, Japan
- Yoshiaki Ono
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]
- Michael Rauch
- ORCiD
- Carnegie Observatories , 813 Santa Barbara Street, Pasadena, CA 91101, USA
- Tomoki Saito
- Nishi-Harima Astronomical Observatory, Centre for Astronomy, University of Hyogo , 407-2 Nishigaichi, Sayo, Sayo-gun, Hyogo 679-5313, Japan
- Rin Sasaki
- Department of Physical Science and Materials Engineering, Faculty of Science and Engineering, Iwate University 3-18-34 Ueda , Morioka, Iwate 020-8550, Japan
- Akihiro Suzuki
- ORCiD
- Research Center for the Early Universe, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- Tsutomu T. Takeuchi
- ORCiD
- Division of Particle and Astrophysical Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464–8602, Japan; The Research Center for Statistical Machine Learning, the Institute of Statistical Mathematics , 10-3 Midori-cho, Tachikawa, Tokyo 190–8562, Japan
- Hiroya Umeda
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Department of Physics, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- Masayuki Umemura
- ORCiD
- Center for Computational Sciences, University of Tsukuba , Ten-nodai, 1-1-1 Tsukuba, Ibaraki 305-8577, Japan
- Kuria Watanabe
- ORCiD
- Department of Astronomical Science, SOKENDAI (The Graduate University for Advanced Studies) , Osawa 2-21-1, Mitaka, Tokyo, 181-8588, Japan
- Kiyoto Yabe
- ORCiD
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo , Kashiwa, Chiba 277-8583, Japan
- Yechi Zhang
- ORCiD
- Institute for Cosmic Ray Research, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan ; [email protected]; Department of Physics, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
- DOI
- https://doi.org/10.3847/1538-4357/accc87
- Journal volume & issue
-
Vol. 951,
no. 2
p. 102
Abstract
We present kinematics of six local extremely metal-poor galaxies (EMPGs) with low metallicities (0.016–0.098 Z _⊙ ) and low stellar masses (10 ^4.7 –10 ^7.6 M _⊙ ). Taking deep medium/high-resolution ( R ∼ 7500) integral-field spectra with 8.2 m Subaru, we resolve the small inner velocity gradients and dispersions of the EMPGs with H α emission. Carefully masking out substructures originating by inflow and/or outflow, we fit three-dimensional disk models to the observed H α flux, velocity, and velocity dispersion maps. All the EMPGs show rotational velocities ( v _rot ) of 5–23 km s ^−1 smaller than the velocity dispersions ( σ _0 ) of 17–31 km s ^−1 , indicating dispersion-dominated ( v _rot / σ _0 = 0.29–0.80 < 1) systems affected by inflow and/or outflow. Except for two EMPGs with large uncertainties, we find that the EMPGs have very large gas-mass fractions of f _gas ≃ 0.9–1.0. Comparing our results with other H α kinematics studies, we find that v _rot / σ _0 decreases and f _gas increases with decreasing metallicity, decreasing stellar mass, and increasing specific star formation rate. We also find that simulated high- z ( z ∼ 7) forming galaxies have gas fractions and dynamics similar to the observed EMPGs. Our EMPG observations and the simulations suggest that primordial galaxies are gas-rich dispersion-dominated systems, which would be identified by the forthcoming James Webb Space Telescope observations at z ∼ 7.
Keywords