论文标题
在附近的星系中搜索异常的微波排放。 K频段观察与萨迪尼亚射电望远镜观察
Searching for Anomalous Microwave Emission in nearby galaxies. K-band observations with the Sardinia Radio Telescope
论文作者
论文摘要
我们在K带中观察到四个附近的螺旋星系（NGC 3627，NGC 4254，NGC 4736和NGC 5055），具有64-m的sardinia射电望远镜，目的是检测到异常的微波发射（AME），另一个散发式的散发性，同样是旋转的，同样是旋转的，同样是旋转的，同样是旋转的，同样是在旋转的范围。仅（最著名的是M 31）。我们在18.6和24.6 GHz绘制了星系，并研究了它们的全局光度法以及文献中的其他无线电数据，以便将AME视为超过同步基因和热成分的发射。我们只找到AME的上限。这些非检测以及文献中的其他上限与少数检测的平均AME发射率是一致的：它是$ε^\ Mathrm {ame} _ {\ Mathrm {\ Mathrm {30〜ghz}}}} （M $ _ \ odot $ PC $^{ - 2} $）$^{ - 1} $以灰尘表面密度为单位（等效地，$ 1.4 \ pm0.2 \ times 10^{ - 18} $ jy sr $^{ - jy sr $^{ - 1} $（h cm $^cm $^{ - 2} $^{ - 2} $）我们最终建议在静态螺旋中搜索AME，其无线电发光度相对较低，例如M〜31。
We observed four nearby spiral galaxies (NGC 3627, NGC 4254, NGC 4736 and NGC 5055) in the K band with the 64-m Sardinia Radio Telescope, with the aim of detecting the Anomalous Microwave Emission (AME), a radiation component presumably due to spinning dust grains, observed so far in the Milky Way and in a handful of other galaxies only (most notably, M 31). We mapped the galaxies at 18.6 and 24.6 GHz and studied their global photometry together with other radio-continuum data from the literature, in order to find AME as emission in excess of the synchrotron and thermal components. We only find upper limits for AME. These non-detections, and other upper limits in the literature, are nevertheless consistent with the average AME emissivity from the few detections: it is $ε^\mathrm{AME}_{\mathrm{30~GHz}} = 2.4\pm0.4 \times 10^{-2}$ MJy sr$^{-1}$ (M$_\odot$ pc$^{-2}$)$^{-1}$ in units of dust surface density (equivalently, $1.4\pm0.2 \times 10^{-18}$ Jy sr$^{-1}$ (H cm$^{-2}$)$^{-1}$ in units of H column density). We finally suggest to search for AME in quiescent spirals with relatively low radio luminosity, such as M~31.
