The birth of a galaxy – II. The role of radiation pressure
The birth of a galaxy – II. The role of radiation pressure
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星系的诞生 – II. 辐射压的作用
DOI：
10.1111/j.1365-2966.2012.21809.x
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发表时间：
2012
影响因子：
4.8
通讯作者：
Britton D. Smith
中科院分区：
文献类型：
--
作者：
J. Wise;Tom Abel;M. Turk;M. Norman;Britton D. Smith
大质量恒星提供反馈，在所有红移和由此产生的恒星种群中塑造星系的星际介质。在这里，我们提出了三个自适应网格细化辐射流体动力学模拟，说明了从电离辐射到吸收气体的动量转移对高红移矮星系中星星形成的影响。动量传递的计算是通过求解辐射传递方程与光线跟踪算法，是自适应的空间和角坐标。我们发现，动量输入部分影响星星的形成，通过增加湍流支持三维均方根速度等于早期晕的圆周速度。与忽略辐射压的计算相比，在暗物质和恒星质量分别为2.0 × 108 M <$$>和4.5 × 105 M <$$>的矮星系中，当包括辐射压时，星星形成率降低了5倍，为1.8 × 10 −2 M <$yr −1。它的平均金属丰度为10 −2.1 Z，与观测到的矮星系光度-金属丰度关系一致。然而，人们可能会天真地从没有辐射压力的计算中期望，星系的中心区域过冷并产生致密、富含金属的恒星群，平均金属丰度为0.3 Z⊙，这表明物理配方不正确。除了H ii区域的光加热，辐射压力进一步驱动来自星星形成区域的致密气体，因此超新星反馈发生在更温暖和更扩散的介质中，发射富含金属的外流。捕捉这方面和辐射和超新星反馈的开始之间的时间分离是数值模拟的星系，以避免“过冷问题”的重要。我们估计，早期低质量星系中的尘埃不太可能有助于从辐射到气体的动量转移。
Massive stars provide feedback that shapes the interstellar medium of galaxies at all redshifts and their resulting stellar populations. Here we present three adaptive mesh refinement radiation hydrodynamics simulations that illustrate the impact of momentum transfer from ionising radiation to the absorbing gas on star formation in high-redshift dwarf galaxies. Momentum transfer is calculated by solving the radiative transfer equation with a ray tracing algorithm that is adaptive in spatial and angular coordinates. We find that momentum input partially affects star formation by increasing the turbulent support to a three-dimensional rms velocity equal to the circular velocity of early haloes. Compared to a calculation that neglects radiation pressure, the star formation rate is decreased by a factor of five to 1.8 × 10 −2 M⊙ yr −1 in a dwarf galaxy with a dark matter and stellar mass of 2.0 × 10 8 M⊙ and 4.5 × 10 5 M⊙, respectively, when radiation pressure is included. Its mean metallicity of 10 −2.1 Z⊙ is consistent with the observed dwarf galaxy luminosity-metallicity relation. However, what one may naively expect from the calculation without radiation pressure, the central region of the galaxy overcools and produces a compact, metalrich stellar population with an average metallicity of 0.3 Z⊙, indicative of an incorrect physical recipe. In addition to photo-heating in H ii regions, radiation pressure further drives dense gas from star forming regions, so supernovae feedback occurs in a warmer and more diffuse medium, launching metal-rich outflows. Capturing this aspect and a temporal separation between the start of radiative and supernova feedback are numerically important in the modeling of galaxies to avoid the “overcooling problem”. We estimate that dust in early low-mass galaxies is unlikely to aid in momentum transfer from radiation to the gas.
影响因子：
8.7
作者：
Komatsu, E.;Smith, K. M.;Wright, E. L.
通讯作者：
Wright, E. L.
银河管理 à trois：模拟碰撞星系中的磁场
DOI：
10.1111/j.1365-2966.2011.18932.x
发表时间：
2011
影响因子：
4.8
作者：
Kotarba;Johansson;Donnert;Stasyszyn
通讯作者：
Stasyszyn