HEAVY DUST OBSCURATION OF z = 7 GALAXIES IN A COSMOLOGICAL HYDRODYNAMIC SIMULATION
HEAVY DUST OBSCURATION OF z = 7 GALAXIES IN A COSMOLOGICAL HYDRODYNAMIC SIMULATION
复制标题
宇宙学流体力学模拟中 z = 7 个星系的重尘埃遮蔽
DOI：
10.1088/0004-637x/776/1/35
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
R. Cen
中科院分区：
文献类型：
--
作者：
T. Kimm;R. Cen
哈勃太空望远镜用宽视场相机3/红外观测显示，z ~ 7的星系具有非常蓝色的紫外线（UV）颜色，与这些系统由年轻恒星群主导一致，这些恒星群被尘埃中度或轻微衰减。我们利用高分辨率自适应网格细化宇宙学流体动力学模拟研究了标准冷暗物质模型中高z星系的紫外和光学性质。为此，我们用三个参数对198个恒星质量为5 × 108-3 × 1010 M☉的星系进行了全色三维尘埃辐射传递计算：尘埃与金属的比值、消光曲线和恒星直接逃逸光的比例（fesc）。发现我们的恒星质量函数与Gonzalez等人的基本一致，独立于这些参数。我们发现，我们的严重尘埃衰减星系（AV ~ 1.8）也可以合理地匹配适度的紫外线光学颜色，蓝色紫外线斜率以及紫外线光度函数，只要有相当一部分（~ 10%）的光直接从它们逃逸。观测到的紫外线斜率和散射可以用小麦哲伦云型消光曲线更好地解释，而银河系型曲线也可以预测由于2175 Å碰撞而产生的蓝色紫外线。我们期待即将到来的阿塔卡马大型毫米/亚毫米阵列的观测将能够测试这个严重模糊的模型。
Hubble Space Telescope observations with the Wide Field Camera 3/Infrared reveal that galaxies at z ∼ 7 have very blue ultraviolet (UV) colors, consistent with these systems being dominated by young stellar populations with moderate or little attenuation by dust. We investigate UV and optical properties of the high-z galaxies in the standard cold dark matter model using a high-resolution adaptive mesh refinement cosmological hydrodynamic simulation. For this purpose, we perform panchromatic three-dimensional dust radiative transfer calculations on 198 galaxies of stellar mass 5 × 108–3 × 1010 M☉ with three parameters: the dust-to-metal ratio, the extinction curve, and the fraction of directly escaped light from stars (fesc). Our stellar mass function is found to be in broad agreement with Gonzalez et al., independent of these parameters. We find that our heavily dust-attenuated galaxies (AV ∼ 1.8) can also reasonably match modest UV–optical colors, blue UV slopes, as well as UV luminosity functions, provided that a significant fraction (∼10%) of light directly escapes from them. The observed UV slope and scatter are better explained with a Small-Magellanic-Cloud-type extinction curve, whereas a Milky-Way-type curve also predicts blue UV colors due to the 2175 Å bump. We expect that upcoming observations by the Atacama Large Millimeter/submillimeter Array will be able to test this heavily obscured model.
影响因子：
8.7
作者：
Komatsu, E.;Smith, K. M.;Wright, E. L.
通讯作者：
Wright, E. L.