论文标题
矮星系中的无线电搜索无线电搜索的通用概况
Universal profiles for radio searches of dark matter in dwarf galaxies
论文作者
论文摘要
研究了矮小球星系中暗物质歼灭或衰减的弥散无线电发射的现象学。我们介绍（在宇宙射线物理学的背景下）一种用于计算相关同步器信号的新策略。特别是，我们确定了各种制度，在此类比以促使伽马射线的类比中，来自暗物质歼灭/衰减的弥漫性无线电信号可以表示为“光晕”乘以光谱函数的乘法。这些功能是在许多基准情况下首次计算的。此外，我们发现参数区域可以通过通用函数（kr）/r很好地近似地位，其中r是以galacto为中心的距离。我们的理论设置与以前的工作不同，而不是采用图像策略，而是考虑相关绿色功能的傅立叶模式扩展。通过此策略，可以通过非常低的计算成本和通用的暗物质模型获得精确的结果。特别是，可以轻松地将O（10-100）傅立叶模式纳入计算中，以探测问题的最小尺度。我们还提出了一种新的策略，使用（1）易于实现的矮星系的无线电观察结果来搜索暗物质，并且（2）在描述了来自暗物质的同步器信号时没有原本大的变性。最后，在这种情况下，我们在广泛使用的绿色功能公式中纠正了一个错误。我们表明，原始表达式导致系统不正确（在某些情况下 - 在某些情况下会导致 - 扩散特征时间尺度小于能量损失的制度。
The phenomenology of diffuse radio emission from Dark Matter annihilation or decay in dwarf spheroidal galaxies is examined. We introduce (in the context of cosmic-ray physics) a novel strategy for the computation of the relevant synchrotron signals. In particular, we identify various regimes where, in analogy to prompt gamma rays, the diffuse radio signal from dark matter annihilation/decay can be expressed as the multiplication of a "halo" times a spectral function. These functions are computed here for the first time for a number of benchmark cases. Furthermore, we find parameter regions in which the emissivity can be well approximated by a universal function ~ sin(kr)/r, where r is the galacto-centric distance. Our theoretical setup differs from previous work in that, instead of employing a method-of-images strategy, we consider a Fourier-mode expansion of the relevant Green's functions. With this strategy, exact results can be obtained with very low computational cost and for generic dark matter models. In particular, O(10- 100) Fourier modes can be easily incorporated into the computations in order to probe the smallest scales of the problem. We also propose a new strategy to search for dark matter using radio observations of dwarf galaxies that is (1) easy to implement and (2) free of the otherwise large degeneracies in the description of synchrotron signals from dark matter. Finally, we correct a mistake in a widely used Green's function formula in this context. We show that the original expression leads to systematically incorrect - and in some cases divergent - results in the regime where the characteristic time-scale for diffusion is smaller than that for energy losses.
