The cold gas content of bulgeless dwarf galaxies
The cold gas content of bulgeless dwarf galaxies
复制标题
无球核矮星系的冷气体含量
DOI：
10.1111/j.1365-2966.2011.19450.x
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发表时间：
2011
影响因子：
4.8
通讯作者：
J. Wadsley
中科院分区：
文献类型：
--
作者：
K. Pilkington;B. Gibson;F. Calura;A. Brooks;L. Mayer;C. Brook;G. Stinson;R. Thacker;C. G. Few;D. Cunnama;J. Wadsley
我们提出了一个完全宇宙流体动力学矮星系的中性氢（H i）性质的分析，在不同的模拟参数下运行。据Governato等人报道，这个星系的高分辨率，高恒星形成密度阈值版本是第一个成功复制（矮）螺旋星系的模拟，没有任何相关的恒星凸起。我们已经开始详细比较这个模拟的无凸起圆盘的H分布和运动学与在附近矮星样本中观察到的情况。为此，我们从模拟中提取了径向气体密度分布、速度色散（例如速度椭球和湍流）和冷星际介质（ISM）内结构的功率谱。当使用与巨大分子云密度相当的高密度恒星形成阈值时，最高分辨率的矮星具有与自然界中观察到的一致的体积特征，尽管冷气体不像在附近的矮星中观察到的那样径向扩展，导致表面密度有些过高。视距速度色散径向剖面的值与观测到的矮星系非常一致，但由于只跟踪了粒子的流速度，因此包括热速度的修正可能会导致相当平坦的剖面。模拟的ISM功率谱在较小的空间尺度上似乎比小麦哲伦云的功率谱具有更大的功率。我们得出的结论是，由于未解决的恒星形成和秒差距尺度分子云内反馈的物理问题，不可避免的局限性仍然存在。
We present an analysis of the neutral hydrogen (H i) properties of a fully cosmological hydrodynamical dwarf galaxy, run with varying simulation parameters. As reported by Governato et al., the high-resolution, high star formation density threshold version of this galaxy is the first simulation to result in the successful reproduction of a (dwarf) spiral galaxy without any associated stellar bulge. We have set out to compare in detail the H i distribution and kinematics of this simulated bulgeless disc with what is observed in a sample of nearby dwarfs. To do so, we extracted the radial gas density profiles, velocity dispersion (e.g. velocity ellipsoid and turbulence) and the power spectrum of structure within the cold interstellar medium (ISM) from the simulations. The highest resolution dwarf, when using a high-density star formation threshold comparable to densities of giant molecular clouds, possesses bulk characteristics consistent with those observed in nature, though the cold gas is not as radially extended as that observed in nearby dwarfs, resulting in somewhat excessive surface densities. The lines-of-sight velocity dispersion radial profiles have values that are in good agreement with the observed dwarf galaxies, but due to the fact that only the streaming velocities of particles are tracked, a correction to include the thermal velocities can lead to profiles that are quite flat. The ISM power spectra of the simulations appear to possess more power on smaller spatial scales than that of the Small Magellanic Cloud. We conclude that unavoidable limitations remain due to the unresolved physics of star formation and feedback within parsec-scale molecular clouds.
DOI：
10.1088/0004-6256/140/5/1194
发表时间：
2010-07
期刊：
The Astronomical Journal
影响因子：
--
作者：
F. Bigiel;A. Leroy;F. Walter;L. Blitz;E. Brinks;W. D. Blok;B. M. U. Berkeley;Mpia Heidelberg;Nrao;U. Hertfordshire;U. C. Town;C. Observatories
通讯作者：
F. Bigiel;A. Leroy;F. Walter;L. Blitz;E. Brinks;W. D. Blok;B. M. U. Berkeley;Mpia Heidelberg;Nrao;U. Hertfordshire;U. C. Town;C. Observatories