Degeneracies between self-interacting dark matter and supernova feedback as cusp-core transformation mechanisms
Degeneracies between self-interacting dark matter and supernova feedback as cusp-core transformation mechanisms
复制标题
自相互作用暗物质和超新星反馈之间的简并作为尖点-核心转变机制
DOI：
10.1093/mnras/stac994
复制
发表时间：
2022
影响因子：
4.8
通讯作者：
Torrey, Paul
中科院分区：
文献类型：
--
作者：
Burger, Jan D.;Zavala, Jesús;Sales, Laura V.;Vogelsberger, Mark;Marinacci, Federico;Torrey, Paul
我们提出了一套16个高分辨率的流体动力学模拟孤立的矮星系（气体和恒星盘加上恒星凸起）在最初的尖状暗物质（DM）晕，包括DM粒子之间的自相互作用，以及随机星星形成和随后的超新星反馈（SNF），使用恒星反馈模型SMUGGLE实施。模拟从相同的初始条件，我们调节DM自相互作用和SNF的强度，通过系统地改变自相互作用DM（SIDM）的动量传递截面和气体密度阈值星星形成。对于这两个参数的几种组合，DM晕形成具有相似尺寸和形状的恒定密度核。由于SIDM（绝热尖芯变换）形成的核心的晕的速度色散曲线，更接近等温的比那些由于SNF在模拟与突发星星形成（脉冲尖芯变换）的核心的晕。脉冲SNF可以产生正的恒星年龄梯度，并增加星系中心气体的随机运动。模拟的星系在晕与核心，形成的螺旋在空间上更广泛，与恒星的金属丰度梯度是浅（在后期）比其他模拟的星系。气体和恒星的这种可观察到的性质表明引力势的绝热或脉冲演化，可以用来确定DM晕中观察到的核心是通过DM自相互作用还是响应于脉冲SNF形成的。
We present a suite of 16 high-resolution hydrodynamic simulations of an isolated dwarf galaxy (gaseous and stellar disc plus a stellar bulge) within an initially cuspy dark matter (DM) halo, including self-interactions between the DM particles; as well as stochastic star formation and subsequent supernova feedback (SNF), implemented using the stellar feedback modelSMUGGLE. The simulations start from identical initial conditions, and we regulate the strength of DM self-interactions and SNF by systematically varying the self-interacting DM (SIDM) momentum transfer cross-section and the gas density threshold for star formation. The DM halo forms a constant density core of similar size and shape for several combinations of those two parameters. Haloes with cores that are formed due to SIDM (adiabatic cusp-core transformation) have velocity dispersion profiles that are closer to isothermal than those of haloes with cores that are formed due to SNF in simulations with bursty star formation (impulsive cusp-core transformation). Impulsive SNF can generate positive stellar age gradients and increase random motion in the gas at the centre of the galaxy. Simulated galaxies in haloes with cores that were formed adiabatically are spatially more extended, with stellar metallicity gradients that are shallower (at late times) than those of galaxies in other simulations. Such observable properties of the gas and the stars, which indicate either an adiabatic or an impulsive evolution of the gravitational potential, may be used to determine whether observed cores in DM haloes are formed through DM self-interactions or in response to impulsive SNF.