arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1208.3537astro-ph.GA
收藏

螺旋和条形半导体集体效应的N体模拟

N-Body Simulations of Collective Effects in Spiral and Barred Galaxies

Xiaolei Zhang

摘要:

我们提出了引力N体模拟的长期形态演化的盘星系的密度波模式。特别是,我们解决的要求集体效应的地方选择的模拟参数,并表明,使用一个大的重力软化参数的常见做法是负责失败的过去的模拟正确模拟星系的长期演化过程,即使对于那些模拟的基本状态的选择允许出现一个不稳定的模式,一个先决条件,以获得协调的径向质量流模式所需的长期演变的星系沿哈勃序列。我们还表明,在我们改进的模拟中测得的长期演化率与最近先进的星系动力驱动长期演化理论预测的相应速率在令人印象深刻的程度上一致。目前工作的结果,除了对星系的宇宙学演化有直接影响外,也揭示了不可逆性如何从名义上可逆的物理系统中出现的一般问题。

英文摘要:

We present gravitational N-body simulations of the secular morphological evolution of disk galaxies induced by density wave modes. In particular, we address the demands collective effects place on the choice of simulation parameters, and show that the common practice of the use of a large gravity softening parameter was responsible for the failure of past simulations to correctly model the secular evolution process in galaxies, even for those simulations where the choice of basic state allows an unstable mode to emerge, a prerequisite for obtaining the coordinated radial mass flow pattern needed for secular evolution of galaxies along the Hubble sequence. We also demonstrate that the secular evolution rates measured in our improved simulations agree to an impressive degree with the corresponding rates predicted by the recently-advanced theories of dynamically-driven secular evolution of galaxies. The results of the current work, besides having direct implications on the cosmological evolution of galaxies, also shed light on the general question of how irreversibility emerges from a nominally reversible physical system.

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。

↑