학술논문
The 300 pc resolution imaging of a z = 8.31 galaxy: Turbulent ionized gas and potential stellar feedback 600 million years after the Big Bang
Document Type
Working Paper
Author
Tamura, Yoichi; Bakx, Tom J. L. C.; Inoue, Akio K.; Hashimoto, Takuya; Tokuoka, Tsuyoshi; Imamura, Chihiro; Hatsukade, Bunyo; Lee, Minju M.; Moriwaki, Kana; Okamoto, Takashi; Ota, Kazuaki; Umehata, Hideki; Yoshida, Naoki; Zackrisson, Erik; Hagimoto, Masato; Matsuo, Hiroshi; Shimizu, Ikkoh; Sugahara, Yuma; Takeuchi, Tsutomu T.
Source
Subject
Language
Abstract
We present the results of 300 pc resolution ALMA imaging of the [OIII] 88 $\mu$m line and dust continuum emission from a $z = 8.312$ Lyman break galaxy MACS0416_Y1. The velocity-integrated [OIII] emission has three peaks which are likely associated with three young stellar clumps of MACS0416_Y1, while the channel map shows a complicated velocity structure with little indication of a global velocity gradient unlike what was found in [CII] 158 $\mu$m at a larger scale, suggesting random bulk motion of ionized gas clouds inside the galaxy. In contrast, dust emission appears as two individual clumps apparently separating or bridging the [OIII]/stellar clumps. The cross correlation coefficient between dust and ultraviolet-related emission (i.e., [OIII] and ultraviolet continuum) is unity on a galactic scale, while it drops at < 1 kpc, suggesting well mixed geometry of multi-phase interstellar media on sub-kpc scales. If the cutoff scale characterizes different stages of star formation, the cutoff scale can be explained by gravitational instability of turbulent gas. We also report on a kpc-scale off-center cavity embedded in the dust continuum image. This could be a superbubble producing galactic-scale outflows, since the energy injection from the 4 Myr starburst suggested by a spectral energy distribution analysis is large enough to push the surrounding media creating a kpc-scale cavity.
Comment: 18 pages, 6 figures, 1 table, published in ApJ
Comment: 18 pages, 6 figures, 1 table, published in ApJ