No need for dark matter: resolved kinematics of the ultra-diffuse galaxy AGC 114905
No need for dark matter: resolved kinematics of the ultra-diffuse galaxy AGC 114905
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不需要暗物质：超漫射星系 AGC 114905 的解析运动学
DOI：
10.1093/mnras/stab3491
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发表时间：
2022
影响因子：
4.8
通讯作者：
Leisman, Lukas
中科院分区：
文献类型：
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作者：
Mancera Piña, Pavel E;Fraternali, Filippo;Oosterloo, Tom;Adams, Elizabeth A;Oman, Kyle A;Leisman, Lukas
我们提出了新的Hiinterferometric观测的气体丰富的超扩散星系AGC 114905，以前的工作，基于低分辨率的数据，确定为一个离群值的重子塔利-费舍尔关系。新观测的空间分辨率比以前高出2.5倍，揭示了一个规则的海迪盘以约23 km s-1的速度旋转。我们的运动学参数，恢复与一个强大的三维运动学建模拟合技术，表明达到旋转曲线的平坦部分。有趣的是，转动曲线几乎完全可以用重子质量分布来解释。我们发现，一个标准的冷暗物质晕，遵循浓度晕质量关系未能再现旋转曲线的幅度由一个大的利润率。只有浓度极低（可以说是不可行的）的晕才与数据一致。我们还发现，AGC 114905的旋转曲线强烈偏离修正牛顿动力学的预测。星系的倾斜度是独立于我们的模型测量的，仍然是我们分析中最大的不确定性，但相关的误差还不足以使星系与冷暗物质或修改后的牛顿动力学的预期相一致。
We present new Hiinterferometric observations of the gas-rich ultra-diffuse galaxy AGC 114905, which previous work, based on low-resolution data, identified as an outlier of the baryonic Tully–Fisher relation. The new observations, at a spatial resolution ∼2.5 times higher than before, reveal a regular Hidisc rotating at about 23 km s−1. Our kinematic parameters, recovered with a robust 3D kinematic modelling fitting technique, show that the flat part of the rotation curve is reached. Intriguingly, the rotation curve can be explained almost entirely by the baryonic mass distribution alone. We show that a standard cold dark matter halo that follows the concentration–halo mass relation fails to reproduce the amplitude of the rotation curve by a large margin. Only a halo with an extremely (and arguably unfeasible) low concentration reaches agreement with the data. We also find that the rotation curve of AGC 114905 deviates strongly from the predictions of modified Newtonian dynamics. The inclination of the galaxy, which is measured independently from our modelling, remains the largest uncertainty in our analysis, but the associated errors are not large enough to reconcile the galaxy with the expectations of cold dark matter or modified Newtonian dynamics.
DOI：
--
发表时间：
2019
期刊：
Fundamentals of Galaxy Dynamics, Formation and Evolution
影响因子：
--
作者：
J. Landine
通讯作者：
J. Landine