ALMA reveals extended cool gas and hot ionized outflows in a typical star-forming galaxy at $z=7.13$
| Autor: | Akins, Hollis, Fujimoto, Seiji, Finlator, Kristian, Watson, Darach, Knudsen, Kirsten, Richard, Johan, Bakx, Tom, Hashimoto, Takuya, Inoue, Akio, Matsuo, Hiroshi, Michalowski, Michal, Tamura, Yoichi |
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| Rok vydání: | 2022 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/1538-4357/ac795b |
| Popis: | We present spatially-resolved morphological properties of [CII] 158 $\mu$m, [OIII] 88 $\mu$m, dust, and rest-frame ultraviolet (UV) continuum emission for A1689-zD1, a strongly lensed, sub-L* galaxy at $z=7.13$, by utilizing deep Atacama Large Millimeter/submillimeter Array (ALMA) and Hubble Space Telescope (HST) observations. While the [OIII] line and UV continuum are compact, the [CII] line is extended up to a radius of $r \sim 12$ kpc. Using multi-band rest-frame far-infrared (FIR) continuum data ranging from 52-400 $\mu$m, we find an average dust temperature and emissivity index of $T_{\rm dust} = 41^{+17}_{-14}$ K and $\beta = 1.7^{+1.1}_{-0.7}$, respectively, across the galaxy. We find slight differences in the dust continuum profiles at different wavelengths, which may indicate that the dust temperature decreases with distance. We map the star-formation rate (SFR) via IR and UV luminosities and determine a total SFR of $37\pm 1~M_\odot~{\rm yr}^{-1}$ with an obscured fraction of $87\%$. While the [OIII] line is a good tracer of the SFR, the [CII] line shows deviation from the local $L_{\rm [CII]}$-SFR relations in the outskirts of the galaxy. Finally, we observe a clear difference in the line profile between [CII] and [OIII], with significant residuals ($\sim 5\sigma$) in the [OIII] line spectrum after subtracting a single Gaussian model. This suggests a possible origin of the extended [CII] structure from the cooling of hot ionized outflows. The extended [CII] and high-velocity [OIII] emission may both contribute in part to the high $L_{\rm [OIII]}$/$L_{\rm [CII]}$ ratios recently reported in $z>6$ galaxies. Comment: 22 pages, 14 figures, accepted to ApJ, presented at AAS240 |
| Databáze: | arXiv |
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