Strong lensing by fermionic dark matter in galaxies
Strong lensing by fermionic dark matter in galaxies
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星系中费米子暗物质的强透镜效应
DOI：
10.1103/physrevd.94.123004
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发表时间：
2016
影响因子：
5
通讯作者：
R. Ruffini
中科院分区：
文献类型：
--
作者：
Gabriel Gómez;C. Argüelles;V. Perlick;J. Rueda;R. Ruffini
结果表明，热力学平衡的大质量kev费米子的自引力系统正确地描述了星系晕中暗物质(DM)的分布，并预测了一个更密集的量子核心朝向组态的中心。对于费米子质量在$50$kev$\less sim m c^2\less sim 345$kev范围内的费米子，这样的量子核可以是SgrA*中中心致密天体的另一种解释。在这项工作中，我们介绍了这一新的DM模型在类银河系螺旋星系中的引力透镜性质。我们描述了纯DM分量在晕尺度上的透镜效应，其中我们将它们与Navarro-Frenk-White和非奇异等温球DM模型的效应进行了比较，并在银河系中心附近将它们与Schwarzschild BH的效应进行了比较。对于导致最紧凑的Dm核的粒子质量，$mc^2\约10^{2}$kev，我们得出以下结论。在距透镜中心20$pC的距离处，中心物体对透镜性质的影响可以忽略不计。然而，我们表明，在几个kpc的外部区域由DM分布产生的偏转角的测量，结合旋转曲线数据，可以帮助区分不同的DM模型。我们发现，在距离为10^-4的情况下，可能会出现强透镜效应，如多个像和爱因斯坦环。Dm中心核和中心BH产生的偏转角在距离10-6$pC处出现较大差异；在这种情况下，弱场形式不再适用，必须使用精确的广义相对论公式。我们发现量子DM核不显示光子球体，这意味着它们不会投射阴影。类似的结论也适用于上述范围内其他费米子质量和其他星系类型的其他Dm分布。
It has been shown that a self-gravitating system of massive keV fermions in thermodynamic equilibrium correctly describes the dark matter (DM) distribution in galactic halos and predicts a denser quantum core towards the center of the configuration. Such a quantum core, for a fermion mass in the range of $50$ keV $\lesssim m c^2 \lesssim 345$ keV, can be an alternative interpretation of the central compact object in Sgr A*. We present in this work the gravitational lensing properties of this novel DM model in Milky Way-like spiral galaxies. We describe the lensing effects of the pure DM component both on halo scales, where we compare them to the effects of the Navarro-Frenk-White and the Non-Singular Isothermal Sphere DM models, and near the galaxy center, where we compare them with the effects of a Schwarzschild BH. For the particle mass leading to the most compact DM core, $m c^2\approx 10^{2}$ keV, we draw the following conclusions. At distances $r\gtrsim 20$ pc from the center of the lens the effect of the central object on the lensing properties is negligible. However, we show that measurements of the deflection angle produced by the DM distribution in the outer region at a few kpc, together with rotation curve data, could help to discriminate between different DM models. We show that at distances $\sim 10^{-4}$ pc strong lensing effects, such as multiple images and Einstein rings, may occur. Large differences in the deflection angle produced by a DM central core and a central BH appear at distances $r\lesssim 10^{-6}$ pc; in this regime the weak-field formalism is no longer applicable and the exact general-relativistic formula has to be used. We find that quantum DM cores do not show a photon sphere what implies that they do not cast a shadow. Similar conclusions apply to the other DM distributions for other fermion masses in the above specified range and for other galaxy types.
非轴对称扰动对轮廓形成的影响
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
森崎友宏;et al.
通讯作者：
et al.