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arXiv 1009.2500astro-ph.CO
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来自宇宙学模拟的恒星星族梯度:对局部星系质量和环境的依赖

Stellar population gradients from cosmological simulations: dependence on mass and environment in local galaxies

C. Tortora, A. D. Romeo, N. R. Napolitano, V. Antonuccio-Delogu, A. Meza, J. Sommer-Larsen, M. Capaccioli

摘要:

从星系恒星质量的角度分析了N体+流体动力学模拟中星系团和星系团的年龄和金属丰度梯度。矮星系的年龄梯度为零,在星系团和星系团外围的系统中,有一个高的正值的尾部。大质量系统的年龄梯度一般为零,对于最大质量的系统,年龄梯度变为正值。矮星系的金属丰度梯度分布在零附近,随着质量的增加,金属丰度梯度变得更负;大质量星系的金属丰度梯度更陡,但随着质量的增加,趋势变平。特别是,化石群的特点是年龄和金属丰度梯度分布更紧密。我们发现一个很好的协议与当地的观察和独立的模拟。还讨论了中心年龄和金属丰度,以及总的颜色,特定的恒星形成和速度色散的结果。

英文摘要:

The age and metallicity gradients for a sample of group and cluster galaxies from N-body+hydrodynamical simulation are analyzed in terms of galaxy stellar mass. Dwarf galaxies show null age gradient with a tail of high and positive values for systems in groups and cluster outskirts. Massive systems have generally zero age gradients which turn to positive for the most massive ones. Metallicity gradients are distributed around zero in dwarf galaxies and become more negative with mass; massive galaxies have steeper negative metallicity gradients, but the trend flatten with mass. In particular, fossil groups are characterized by a tighter distribution of both age and metallicity gradients. We find a good agreement with both local observations and independent simulations. The results are also discussed in terms of the central age and metallicity, as well as the total colour, specific star formation and velocity dispersion.

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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