| Autor: |
Yi Xu, Masami Ouchi, Yuki Isobe, Kimihiko Nakajima, Shinobu Ozaki, Nicolas F. Bouché, John H. Wise, 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 |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
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| Zdroj: |
The Astrophysical Journal, Vol 961, Iss 1, p 49 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
1538-4357 |
| DOI: |
10.3847/1538-4357/ad06ab |
| Popis: |
We present the demography of the dynamics and gas mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of 0.015–0.195 Z _⊙ and low stellar masses of 10 ^4 –10 ^8 M _⊙ in the local universe. We conduct deep optical integral field spectroscopy (IFS) for the low-mass EMPGs with the medium-high resolution ( R = 7500) grism of the 8 m Subaru FOCAS IFU instrument by the EMPRESS 3D survey, and investigate the H α emission of the EMPGs. Exploiting the resolution high enough for the low-mass galaxies, we derive gas dynamics with the H α lines by the fitting of three-dimensional disk models. We obtain an average maximum rotation velocity ( v _rot ) of 15 ± 3 km s ^−1 and an average intrinsic velocity dispersion ( σ _0 ) of 27 ± 10 km s ^−1 for 15 spatially resolved EMPGs out of 33 EMPGs, and find that all 15 EMPGs have v _rot / σ _0 < 1 suggesting dispersion-dominated systems. There is a clear decreasing trend of v _rot / σ _0 with the decreasing stellar mass and metallicity. We derive the gas mass fraction ( f _gas ) for all 33 EMPGs, and find no clear dependence on stellar mass and metallicity. These v _rot / σ _0 and f _gas trends should be compared with young high- z galaxies observed by the forthcoming JWST IFS programs to understand the physical origins of the EMPGs in the local universe. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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