Physical properties of UDF12 galaxies in cosmological simulations
Physical properties of UDF12 galaxies in cosmological simulations
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宇宙学模拟中 UDF12 星系的物理特性
DOI：
10.1093/mnras/stu265
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发表时间：
2014
影响因子：
4.8
通讯作者：
Naoki
中科院分区：
文献类型：
--
作者：
Shimizu;Ikkoh; Inoue;Akio K.; Okamoto;Takashi; Yoshida;Naoki
我们针对 2012 年使用哈勃太空望远镜进行的深度观测（即所谓的 UDF12 活动）进行了大型宇宙流体动力学模拟。完成光锥输出后，我们应用与 UDF12 活动相同的颜色选择标准来从模拟中选择星系，然后检查它们的物理属性，作为真实观测到的 UDF12 星系 atz> 7 的代理。结果，我们发现光晕质量几乎与观测到的紫外线 (UV) 光度成线性比例 (4 × 1011M⊙atMUV= −21)。尘埃衰减和紫外斜率β与观测到的紫外光度有很好的相关性，这与定量观测结果一致。恒星形成率（SFR）也与恒星质量成线性正比，而特定恒星形成率对质量的依赖性很弱。我们还发现，在高 z 星系中，恒星形成历史不断增加，时间尺度约为 100 Myr。由莱曼连续光度加权的平均金属丰度达到>0.1太阳甚至atz∼10，表明金属快速富集。我们还预计 H160≤ 27 的星系在 350 GHz 处的尘埃热发射≥0.1 mJy，这可以用阿塔卡马大型毫米亚毫米阵列检测到。 UDF12 巡天选择的星系分别只占 z∼7 到 z∼10 宇宙恒星形成率密度的 52%–12%。詹姆斯·韦伯太空望远镜将把探测率提高到 77%–72%。
We have performed a large cosmological hydrodynamics simulation tailored to the deep survey with theHubble Space Telescopemade in 2012, the so-called UDF12 campaign. After making a light-cone output, we have applied the same colour-selection criteria as the UDF12 campaign to select galaxies from our simulation, and then, have examined the physical properties of them as a proxy of the real observed UDF12 galaxies atz> 7. As a result, we find that the halo mass is almost linearly proportional to the observed ultraviolet (UV) luminosity (4 × 1011M⊙atMUV= −21). The dust attenuation and UV slope β well correlates with the observed UV luminosity, which is consistent with observations quantitatively. The star formation rate (SFR) is also linearly proportional to the stellar mass and the specific SFR shows only a weak dependence on the mass. We also find an increasing star formation history with a time-scale of ∼100 Myr in the high-zgalaxies. An average metallicity weighted by the Lyman continuum luminosity reaches up to >0.1 Solar even atz∼ 10, suggesting a rapid metal enrichment. We also expect ≥0.1 mJy at 350 GHz of the dust thermal emission from the galaxies withH160≤ 27, which can be detectable with the Atacama Large Millimetre-sub-millimetre Array. The galaxies selected by the UDF12 survey contribute to only 52–12 per cent of the cosmic SFR density fromz∼ 7 toz∼ 10, respectively. The James Webb Space Telescope will push the detection fraction up to 77–72 per cent.