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arXiv 1902.01665astro-ph.GAastro-ph.CO
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是什么塑造了星系?- 揭开质量、环境和恒星形成在形成星系结构中的作用

What shapes a galaxy? - Unraveling the role of mass, environment and star formation in forming galactic structure

Asa F. L. Bluck, Connor Bottrell, Hossen Teimoorinia, Bruno M. B. Henriques, J. Trevor Mendel, Sara L. Ellison, Karun Thanjavur, Luc Simard, David R. Patton, Ch… 展开作者

Asa F. L. Bluck, Connor Bottrell, Hossen Teimoorinia, Bruno M. B. Henriques, J. Trevor Mendel, Sara L. Ellison, Karun Thanjavur, Luc Simard, David R. Patton, Christopher J. Conselice, Jorge Moreno, Joanna Woo

摘要:

我们研究了来自斯隆数字巡天数据发布7(SDSS-DR 7)的约500,000个z<0.2的星系的星系结构对各种星系和环境参数的依赖性。我们利用膨胀与恒星总质量的比值(B/T)_* 作为星系结构的主要指标,避免了形态学对波段依赖的问题。我们使用人工神经网络方法,根据星系结构的预测性对星系和环境参数进行排名。我们发现离恒星形成主序星的距离(Delta_SFR)和恒星质量(M_*)是与(B/T)_* 关系最密切的参数,它们对星系结构的预测能力明显强于恒星形成速率(SFR)或任何环境度量(无论是中央星系还是卫星星系)。此外,我们做了详细的比较,以Illustris流体动力学模拟和LGalerkin半解析模型。在这两个模拟中,我们发现一个显着缺乏在一个固定的恒星质量的膨胀为主的星系相比,SDSS。这一结果凸显了当代星系演化模型中一个潜在的严重问题。

英文摘要:

We investigate the dependence of galaxy structure on a variety of galactic and environmental parameters for ~500,000 galaxies at z<0.2, taken from the Sloan Digital Sky Survey data release 7 (SDSS-DR7). We utilise bulge-to-total stellar mass ratio, (B/T)_*, as the primary indicator of galactic structure, which circumvents issues of morphological dependence on waveband. We rank galaxy and environmental parameters in terms of how predictive they are of galaxy structure, using an artificial neural network approach. We find that distance from the star forming main sequence (Delta_SFR), followed by stellar mass (M_*), are the most closely connected parameters to (B/T)_*, and are significantly more predictive of galaxy structure than global star formation rate (SFR), or any environmental metric considered (for both central and satellite galaxies). Additionally, we make a detailed comparison to the Illustris hydrodynamical simulation and the LGalaxies semi-analytic model. In both simulations, we find a significant lack of bulge-dominated galaxies at a fixed stellar mass, compared to the SDSS. This result highlights a potentially serious problem in contemporary models of galaxy evolution.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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