THE CORE–CUSP PROBLEM IN COLD DARK MATTER HALOS AND SUPERNOVA FEEDBACK: EFFECTS OF OSCILLATION
THE CORE–CUSP PROBLEM IN COLD DARK MATTER HALOS AND SUPERNOVA FEEDBACK: EFFECTS OF OSCILLATION
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DOI：
10.1088/0004-637x/793/1/46
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发表时间：
2010-10
期刊：
影响因子：
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通讯作者：
G. Ogiya;M. Mori
中科院分区：
文献类型：
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作者：
G. Ogiya;M. Mori
本研究探讨暗物质晕对周期性星暴形成较小质量星系的动力学响应，以解决核心尖点问题。恒星爆发后，气体被超新星反馈加热，膨胀，然后终止星星的形成。这种膨胀的气体通过辐射冷却失去能量，然后福尔斯又落回星系中心。随后，星爆再次增强。星际气体的这种膨胀和收缩的循环导致了气体引力势的重复变化。DM粒子与振荡势激发的密度波之间的共振对理解DM晕尖核跃迁的物理机制起着关键作用。DM晕通过粒子与密度波共振驱动的能量转移，有效地从重子势中获得动能。我们确定了尖核转变的临界条件是气体势的振荡周期与DM晕的局域动力学时间近似相等。利用冷暗物质模型预测的常规质量密度分布，我们给出了由共振引起的尖核-核跃迁后DM晕的核半径。此外，我们使用N体模拟验证了解析模型，结果验证了共振模型。
This study investigates the dynamical response of dark matter (DM) halos to recurrent starbursts in forming less-massive galaxies to solve the core–cusp problem. The gas, which is heated by supernova feedback after a starburst, expands and the star formation then terminates. This expanding gas loses energy by radiative cooling and then falls back toward the galactic center. Subsequently, the starburst is enhanced again. This cycle of expansion and contraction of the interstellar gas leads to a repetitive change in the gravitational potential of the gas. The resonance between DM particles and the density wave excited by the oscillating potential plays a key role in understanding the physical mechanism of the cusp–core transition of DM halos. DM halos effectively gain kinetic energy from the baryon potential through the energy transfer driven by the resonance between the particles and density waves. We determine that the critical condition for the cusp–core transition is such that the oscillation period of the gas potential is approximately the same as the local dynamical time of DM halos. We present the resultant core radius of a DM halo after the cusp–core transition induced by the resonance by using the conventional mass density profile predicted by the cold dark matter models. Moreover, we verify the analytical model by using N-body simulations, and the results validate the resonance model.