论文标题

不对称暗物质对恒星进化I的影响:旋转依赖性散射

The Effects of Asymmetric Dark Matter on Stellar Evolution I: Spin-Dependent Scattering

论文作者

Raen, Troy J., Martínez-Rodríguez, Héctor, Hurst, Travis J., Zentner, Andrew R., Badenes, Carles, Tao, Rachel

论文摘要

在过去的几十年中,大多数暗物质(DM)搜索都集中在wimp上,但是可行的参数空间迅速缩小。不对称的暗物质(ADM)是一个像wimp的DM候选者,质量稍小,没有当今的an灭,这意味着恒星可以捕获和积累大量。被捕获的ADM可以通过大量恒星运输能量。我们研究了自旋依赖性ADM能量传输对恒星结构的影响,并在不同的DM环境中以$ 0.9 \ leq m _ {\ star}/\ mathrm {\ odot} _ {\ odot} \ leq 5.0 $的恒星进化。我们编写了一个台面模块,该模块计算了DM的捕获和随后的恒星中的能量传输。我们将DM质量固定到5 GEV,将横截面固定到$ 10^{ - 37} \ Mathrm {cm {^2}} $,并通过缩放DM捕获率来研究不同的环境。对于带有辐射核的星星($ M _ {\ star} \ Lessim 1.3 \ \ Mathrm {M} _ {\ odot} $),ADM的存在使核心的温度和燃烧曲线平移,并增加了MS($ x_c> 10^{ - 3} $)的生命,从而通过$ \ sim $ \ $ \%$ \%。我们发现,对节能的严格要求对于模拟ADM对这些恒星的影响至关重要。在高质量的恒星中,ADM Energy Transport关闭了核心对流,将可用的燃料限制并缩短了MS寿命最高$ \ sim 40 \%$。这可能转化为种群等温线中MS下降的亮度和有效温度的变化。红色巨型分支的尖端可能出现在较低的亮度下。在高密度和/或低速分散的DM环境中,效果最大,使矮人和早期形成星系最有可能显示出效果。

Most of the dark matter (DM) search over the last few decades has focused on WIMPs, but the viable parameter space is quickly shrinking. Asymmetric Dark Matter (ADM) is a WIMP-like DM candidate with slightly smaller masses and no present day annihilation, meaning that stars can capture and build up large quantities. The captured ADM can transport energy through a significant volume of the star. We investigate the effects of spin-dependent ADM energy transport on stellar structure and evolution in stars with $0.9 \leq M_{\star}/\mathrm{M}_{\odot} \leq 5.0$ in varying DM environments. We wrote a MESA module that calculates the capture of DM and the subsequent energy transport within the star. We fix the DM mass to 5 GeV and the cross section to $10^{-37} \mathrm{cm{^2}}$, and study varying environments by scaling the DM capture rate. For stars with radiative cores ($M_{\star} \lesssim 1.3\ \mathrm{M}_{\odot}$), the presence of ADM flattens the temperature and burning profiles in the core and increases MS ($X_c > 10^{-3}$) lifetimes by up to $\sim 20\%$. We find that strict requirements on energy conservation are crucial to the simulation of ADM's effects on these stars. In higher-mass stars, ADM energy transport shuts off core convection, limiting available fuel and shortening MS lifetimes by up to $\sim 40\%$. This may translate to changes in the luminosity and effective temperature of the MS turnoff in population isochrones. The tip of the red giant branch may occur at lower luminosities. The effects are largest in DM environments with high densities and/or low velocity dispersions, making dwarf and early forming galaxies most likely to display the effects.

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