论文标题
M87球状簇的离散化学动力模型:延伸至400 kpc的运动学
A discrete chemo-dynamical model of M87's globular clusters: Kinematics extending to ~ 400 kpc
论文作者
论文摘要
我们使用离散的化学动力,轴对称牛仔裤方程建模研究了巨型椭圆星系M87(NGC 4486)的质量分布和运动学。我们的目录包括894个球状簇(GCS),这些簇扩展到$ \ sim 430 $ kpc的预计半径,带有视线速度和颜色,以及多单元光谱探索器(MUSES)集成电单位单位数据中的中央$ 2.4 $ kpc in Main Galaxy的中央$ 2.4 $ kpc。我们模型的引力潜力是将发光物质潜力与主星系的质量与光比不同,超质量黑洞和暗物质(DM)电位(DM)电位(dm)电势,带有cus或cused dm halo。具有cused或cused DM光环的最佳拟合模型没有显着差异,并且两者都是可以接受的。我们在$ \ sim $ 400 kpc中获得了$(2.16 \ pm 0.38)\ times 10^{13} m _ {\ odot} $。通过包括出色的质量比率梯度,DM分数从$ \ sim $ \ sim $ 26%(没有梯度)增加到$ \ sim $ \ sim $ 73%,$ 73%,$ 73%,$ 1 \,r_e^{\ rm maj maj} $(半光iSophote的主要轴,14.2 kpc),从$ \ sim $ 84%$ 94% $ 5 \,r_e^{\ rm maj} $(71.2 kpc)。红色GC具有$ V _ {\ rm max}/σ\ sim $ 0.4的中等旋转,并且蓝色GC的旋转较弱,$ v _ {\ rm max}/σ\ sim $ 0.1。红色GC具有切向速度分散各向异性,而蓝色GC与几乎各向同性的一致。我们的结果表明,红色GC更有可能在原位出生,而蓝色GC则更有可能被吸收。
We study the mass distribution and kinematics of the giant elliptical galaxy M87 (NGC 4486) using discrete chemo-dynamical, axisymmetric Jeans equation modelling. Our catalogue comprises 894 globular clusters (GCs) extending to a projected radius of $\sim 430$ kpc with line-of-sight velocities and colours, and Multi Unit Spectroscopic Explorer (MUSE) integral field unit data within the central $2.4$ kpc of the main galaxy. The gravitational potential for our models is a combination of a luminous matter potential with a varying mass-to-light ratio for the main galaxy, a supermassive black hole and a dark matter (DM) potential with a cusped or cored DM halo. The best-fitting models with either a cusped or a cored DM halo show no significant differences and both are acceptable. We obtain a total mass of $(2.16 \pm 0.38) \times 10^{13} M_{\odot}$ within $\sim$ 400 kpc. By including the stellar mass-to-light ratio gradient, the DM fraction increases from $\sim$ 26 percent (with no gradient) to $\sim$ 73 percent within $1\,R_e^{\rm maj}$ (major axis of half-light isophote, 14.2 kpc), and from $\sim$ 84 percent to $\sim$ 94 percent within $5\,R_e^{\rm maj}$ (71.2 kpc). Red GCs have moderate rotation with $V_{\rm max}/σ\sim$ 0.4, and blue GCs have weak rotation with $V_{\rm max}/σ\sim$ 0.1. Red GCs have tangential velocity dispersion anisotropy, while blue GCs are consistent with being nearly isotropic. Our results suggest that red GCs are more likely to be born in-situ, while blue GCs are more likely to be accreted.