_version_ 1866914653211197440
author Xu, Yi
Ouchi, Masami
Isobe, Yuki
Nakajima, Kimihiko
Ozaki, Shinobu
Bouché, Nicolas F.
Wise, John H.
Emsellem, Eric
Kusakabe, Haruka
Hattori, Takashi
Nagao, Tohru
Chiaki, Gen
Fukushima, Hajime
Harikane, Yuichi
Hayashi, Kohei
Hirai, Yutaka
Kim, Ji Hoon
Maseda, Michael V.
Nagamine, Kentaro
Shibuya, Takatoshi
Sugahara, Yuma
Yajima, Hidenobu
Aoyama, Shohei
Fujimoto, Seiji
Fukushima, Keita
Hatano, Shun
Inoue, Akio K.
Ishigaki, Tsuyoshi
Kawasaki, Masahiro
Kojima, Takashi
Komiyama, Yutaka
Koyama, Shuhei
Koyama, Yusei
Lee, Chien-Hsiu
Matsumoto, Akinori
Mawatari, Ken
Moriya, Takashi J.
Motohara, Kentaro
Murai, Kai
Nishigaki, Moka
Onodera, Masato
Ono, Yoshiaki
Rauch, Michael
Saito, Tomoki
Sasaki, Rin
Suzuki, Akihiro
Takeuchi, Tsutomu T.
Umeda, Hiroya
Umemura, Masayuki
Watanabe, Kuria
Yabe, Kiyoto
Zhang, Yechi
author_facet Xu, Yi
Ouchi, Masami
Isobe, Yuki
Nakajima, Kimihiko
Ozaki, Shinobu
Bouché, Nicolas F.
Wise, John H.
Emsellem, Eric
Kusakabe, Haruka
Hattori, Takashi
Nagao, Tohru
Chiaki, Gen
Fukushima, Hajime
Harikane, Yuichi
Hayashi, Kohei
Hirai, Yutaka
Kim, Ji Hoon
Maseda, Michael V.
Nagamine, Kentaro
Shibuya, Takatoshi
Sugahara, Yuma
Yajima, Hidenobu
Aoyama, Shohei
Fujimoto, Seiji
Fukushima, Keita
Hatano, Shun
Inoue, Akio K.
Ishigaki, Tsuyoshi
Kawasaki, Masahiro
Kojima, Takashi
Komiyama, Yutaka
Koyama, Shuhei
Koyama, Yusei
Lee, Chien-Hsiu
Matsumoto, Akinori
Mawatari, Ken
Moriya, Takashi J.
Motohara, Kentaro
Murai, Kai
Nishigaki, Moka
Onodera, Masato
Ono, Yoshiaki
Rauch, Michael
Saito, Tomoki
Sasaki, Rin
Suzuki, Akihiro
Takeuchi, Tsutomu T.
Umeda, Hiroya
Umemura, Masayuki
Watanabe, Kuria
Yabe, Kiyoto
Zhang, Yechi
contents We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of $0.015-0.195~Z_\odot$ and low stellar masses of $10^4-10^8~M_\odot$ 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 8m-Subaru FOCAS IFU instrument by the EMPRESS 3D survey, and investigate 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 3-dimensional disk models. We obtain an average maximum rotation velocity ($v_\mathrm{rot}$) of $15\pm3~\mathrm{km~s^{-1}}$ and an average intrinsic velocity dispersion ($σ_0$) of $27\pm10~\mathrm{km~s^{-1}}$ for 15 spatially resolved EMPGs out of the 33 EMPGs, and find that all of the 15 EMPGs have $v_\mathrm{rot}/σ_0<1$ suggesting dispersion dominated systems. There is a clear decreasing trend of $v_\mathrm{rot}/σ_0$ with the decreasing stellar mass and metallicity. We derive the gas mass fraction ($f_\mathrm{gas}$) for all of the 33 EMPGs, and find no clear dependence on stellar mass and metallicity. These $v_\mathrm{rot}/σ_0$ and $f_\mathrm{gas}$ 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.
format Preprint
id arxiv_https___arxiv_org_abs_2303_12467
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies
Xu, Yi
Ouchi, Masami
Isobe, Yuki
Nakajima, Kimihiko
Ozaki, Shinobu
Bouché, Nicolas F.
Wise, John H.
Emsellem, Eric
Kusakabe, Haruka
Hattori, Takashi
Nagao, Tohru
Chiaki, Gen
Fukushima, Hajime
Harikane, Yuichi
Hayashi, Kohei
Hirai, Yutaka
Kim, Ji Hoon
Maseda, Michael V.
Nagamine, Kentaro
Shibuya, Takatoshi
Sugahara, Yuma
Yajima, Hidenobu
Aoyama, Shohei
Fujimoto, Seiji
Fukushima, Keita
Hatano, Shun
Inoue, Akio K.
Ishigaki, Tsuyoshi
Kawasaki, Masahiro
Kojima, Takashi
Komiyama, Yutaka
Koyama, Shuhei
Koyama, Yusei
Lee, Chien-Hsiu
Matsumoto, Akinori
Mawatari, Ken
Moriya, Takashi J.
Motohara, Kentaro
Murai, Kai
Nishigaki, Moka
Onodera, Masato
Ono, Yoshiaki
Rauch, Michael
Saito, Tomoki
Sasaki, Rin
Suzuki, Akihiro
Takeuchi, Tsutomu T.
Umeda, Hiroya
Umemura, Masayuki
Watanabe, Kuria
Yabe, Kiyoto
Zhang, Yechi
Astrophysics of Galaxies
We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of $0.015-0.195~Z_\odot$ and low stellar masses of $10^4-10^8~M_\odot$ 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 8m-Subaru FOCAS IFU instrument by the EMPRESS 3D survey, and investigate 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 3-dimensional disk models. We obtain an average maximum rotation velocity ($v_\mathrm{rot}$) of $15\pm3~\mathrm{km~s^{-1}}$ and an average intrinsic velocity dispersion ($σ_0$) of $27\pm10~\mathrm{km~s^{-1}}$ for 15 spatially resolved EMPGs out of the 33 EMPGs, and find that all of the 15 EMPGs have $v_\mathrm{rot}/σ_0<1$ suggesting dispersion dominated systems. There is a clear decreasing trend of $v_\mathrm{rot}/σ_0$ with the decreasing stellar mass and metallicity. We derive the gas mass fraction ($f_\mathrm{gas}$) for all of the 33 EMPGs, and find no clear dependence on stellar mass and metallicity. These $v_\mathrm{rot}/σ_0$ and $f_\mathrm{gas}$ 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.
title EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2303.12467