ALMA Reveals Extended Cool Gas and Hot Ionized Outflows in a Typical Star-forming Galaxy at Z = 7.13
ALMA Reveals Extended Cool Gas and Hot Ionized Outflows in a Typical Star-forming Galaxy at Z = 7.13
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DOI：
10.3847/1538-4357/ac795b
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发表时间：
2022-06
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通讯作者：
H. Akins;S. Fujimoto;K. Finlator;D. Watson;K. Knudsen;J. Richard;Tom J. L. C. Bakx;T. Hashimoto;A. Inoue;H. Matsuo;M. Michałowski;Y. Tamura
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作者：
H. Akins;S. Fujimoto;K. Finlator;D. Watson;K. Knudsen;J. Richard;Tom J. L. C. Bakx;T. Hashimoto;A. Inoue;H. Matsuo;M. Michałowski;Y. Tamura
利用深阿塔卡马大型毫米/亚毫米阵列（阿尔马）和哈勃空间望远镜（HST）观测，给出了A1689-zD 1（z = 7.13的强透镜亚L * 星系）的[C II] 158 μ m、[O III] 88 μm、尘埃和静止帧紫外（UV）连续辐射的空间分辨形态学特性。虽然[O III]线和UV连续谱是紧凑的，但[C II]线延伸到半径r = 12 kpc。利用52 - 400 μm的多波段静止帧远红外连续光谱数据，我们发现整个星系的平均尘埃温度和发射率指数分别为Tdust=41−14+17 K和β=1.7−0.7+1.1。我们发现在不同的波长，这可能表明，尘埃温度随距离减小的尘埃连续轮廓略有差异。我们通过红外和紫外光度绘制了星星形成率（SFR）图，并确定了总SFR为37 ± 1百万光年−1，遮蔽率为87%。虽然[O III]线是一个很好的示踪剂的SFR，[C II]线显示偏离当地的L [C II]-SFR的关系在星系的外围。最后，我们观察到[C II]和[O III]之间的谱线轮廓有明显的差异，在减去单个高斯模型后，[O III]的谱线中有显著的残差（Δ 5σ）。这表明一个可能的起源扩展[C II]结构从热电离流出冷却。扩展的[C II]和高速[O III]发射可能都有助于最近报道的z > 6星系的高L [O III]/L [C II]比。
We present spatially resolved morphological properties of [C II] 158 μm, [O III] 88 μm, 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 [O III] line and UV continuum are compact, the [C II] line is extended up to a radius of r ∼ 12 kpc. Using multi-band rest-frame far-infrared continuum data ranging from 52 to 400 μm, we find an average dust temperature and emissivity index of Tdust=41−14+17 K and β=1.7−0.7+1.1 , 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 ± 1M ⊙yr−1 with an obscured fraction of 87%. While the [O III] line is a good tracer of the SFR, the [C II] line shows deviation from the local L [C II]-SFR relations in the outskirts of the galaxy. Finally, we observe a clear difference in the line profile between [C II] and [O III], with significant residuals (∼5σ) in the [O III] line spectrum after subtracting a single Gaussian model. This suggests a possible origin of the extended [C II] structure from the cooling of hot ionized outflows. The extended [C II] and high-velocity [O III] emission may both contribute in part to the high L [O III]/L [C II] ratios recently reported in z > 6 galaxies.