We follow up on a report by Vacca et al. (2018) of 28 candidate large-scale diffuse synchrotron sources in an 8° × 8° area of the sky (centred at RA 5h0m0s; Dec 5°48ʹ00ʹʹ). These sources were originally observed at 1.4 GHz using a combination of the single-dish Sardinia Radio Telescope and archival NRAO VLA Sky Survey data. They are in an area with nine massive galaxy clusters at $z \approx 0.1$ and are candidates for the first detection of filaments of the synchrotron cosmic web. We attempt to verify these candidate sources with lower frequency observations at 154 MHz with the Murchison Widefield Array and at 887 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP). We use a novel technique to calculate the surface brightness sensitivity of these instruments to show that our lower frequency observations, and in particular those by ASKAP, are ideally suited to detect large-scale, extended synchrotron emission. Nonetheless, we are forced to conclude that none of these sources are likely to be synchrotron in origin or associated with the cosmic web.

中文翻译：

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28 个候选大型同步加速器源的低（ER）频率跟踪

我们跟进了 Vacca 等人的报告。(2018) 28 个候选大规模漫射同步加速器源在 8°× 8°天空区域（以 RA 5 为中心H0米0s; 12月5日°48ʹ00ʹʹ）。这些源最初是使用单碟撒丁岛射电望远镜和存档的 NRAO VLA 巡天数据在 1.4 GHz 观测到的。他们所在的区域有九个巨大的星系团，位于 $z \约 0.1$ 并且是首次探测同步加速器宇宙网细丝的候选者。我们尝试使用 Murchison 宽场阵列在 154 MHz 和使用澳大利亚平方公里阵列探路者 (ASKAP) 的 887 MHz 以较低频率观测来验证这些候选源。我们使用一种新技术来计算这些仪器的表面亮度灵敏度，以表明我们的低频观测，特别是 ASKAP 的观测，非常适合检测大规模、扩展的同步辐射。尽管如此，我们不得不得出结论，这些来源都不太可能起源于同步加速器或与宇宙网有关。