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arXiv 2407.12482astro-ph.GAastro-ph.COgr-qc
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利用Gaia DR3探索银河系旋转曲线:ΛCDM、MOND和广义相对论方法的比较

Exploring Milky Way rotation curves with Gaia DR3: a comparison between $Λ$CDM, MOND, and General Relativistic approaches

University of Turin(都灵大学)

William Beordo, Mariateresa Crosta, Mario Gilberto Lattanzi

AI总结:

利用Gaia DR3数据,比较ΛCDM、MOND和广义相对论模型在解释银河系旋转曲线中的表现,发现所有模型在统计上等价,但ΛCDM暗物质分布高于其他模型。

摘要:

随着Gaia DR3的发布,我们扩展了之前工作中对银河系旋转曲线动态模型的比较。利用719143颗年轻盘状恒星的天文学测量和光谱-光度数据,这些恒星位于|z| < 1kpc以内,直到R≈19kpc,我们研究了MOND和ΛCDM框架以及之前研究过的模型,如具有纳瓦罗-弗伦克-怀特暗物质晕的经典模型和广义相对论模型。我们发现所有模型,包括MOND和ΛCDM,在表示观测到的旋转速度方面在统计上是等价的。然而,ΛCDM,其特征是Einasto密度剖面和对参数的宇宙学约束,比具有纳瓦罗-弗伦克-怀特剖面的模型分配了更多的暗物质,估计的virial质量为1.5-2.5×10^12 M⊙ - 一个值显著高于最近文献估计值。在超过10-15kpc之后,所有模型中非牛顿/非恒星成分对旋转曲线的贡献被认为变得主导。我们的结果表明,需要进一步探索广义相对论、暗物质和引力动力学替代理论在塑造银河系旋转曲线中的作用。

英文摘要:

With the release of Gaia DR3, we extend the comparison between dynamical models for the Milky Way rotation curve initiated in the previous work. Utilising astrometric and spectro-photometric data for 719143 young disc stars within $|z|<1$ kpc and up to $R \simeq 19$ kpc, we investigate the accuracy of MOND and $Λ$CDM frameworks in addition to previously studied models, such as the classical one with a Navarro-Frenk-White dark matter halo and a general relativistic model. We find that all models, including MOND and $Λ$CDM, are statistically equivalent in representing the observed rotational velocities. However, $Λ$CDM, characterized by an Einasto density profile and cosmological constraints on its parameters, assigns more dark matter than the model featuring a Navarro-Frenk-White profile, with the virial mass estimated at $1.5\text{-}2.5 \times 10^{12} \, {\rm M}_{\odot}$ - a value significantly higher than recent literature estimates. Beyond $10\text{-}15$ kpc, non-Newtonian/non-baryonic contributions to the rotation curve are found to become dominant for all models consistently. Our results suggest the need for further exploration into the role of General Relativity, dark matter, and alternative theories of gravitational dynamics in shaping Milky Way's rotation curve.

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。

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