We test the hypothesis that environments play a key role in enabling the growth of enormous radio structures spanning more than 700 kpc, an extreme population of radio galaxies called giant radio galaxies (GRGs). To achieve this, we explore (1) the relationships between the occurrence of GRGs and the surface number density of surrounding galaxies, including satellite galaxies and galaxies from neighbouring haloes, and (2) the GRG locations towards large-scale structures. The analysis is done by making use of a homogeneous sample of 110 GRGs detected from the LOFAR Two-metre Sky Survey in combination with photometric galaxies from the DESI Legacy Imaging Surveys and a large-scale filament catalogue from the Sloan Digital Sky Survey. Our results show that the properties of galaxies around GRGs are similar with that around the two control samples, consisting of galaxies with optical colours and luminosity matched to the properties of the GRG host galaxies. Additionally, the properties of surrounding galaxies depend on neither their relative positions to the radio jet/lobe structures nor the sizes of GRGs. We also find that the locations of GRGs and the control samples with respect to the nearby large-scale structures are consistent with each other. These results demonstrate that there is no correlation between the GRG properties and their environments traced by stars, indicating that external galaxy environments are not the primary cause of the large sizes of the radio structures. Finally, regarding radio feedback, we show that the fraction of blue satellites does not correlate with the GRG properties, suggesting that the current epoch of radio jets has minimal influence on the nature of their surrounding galaxies.

中文翻译：

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关于巨大射电星系的环境

我们检验了这样一个假设，即环境在使跨越超过 700 kpc 的巨大无线电结构的增长中发挥着关键作用，这是一种称为巨型无线电星系 (GRG) 的极端无线电星系群。为了实现这一目标，我们探索了（1）GRG 的出现与周围星系的表面数密度之间的关系，包括卫星星系和来自邻近晕圈的星系，以及（2）GRG 朝向大型结构的位置。该分析是通过利用从 LOFAR 两米天空调查中检测到的 110 个 GRG 的均匀样本，结合来自 DESI 传统成像调查的光度星系和来自斯隆数字天空调查的大型灯丝目录来完成的。我们的结果表明，GRGs 周围星系的性质与两个对照样本周围的相似，由具有与 GRG 宿主星系的特性相匹配的光学颜色和光度的星系组成。此外，周围星系的性质既不取决于它们与射电射流/波瓣结构的相对位置，也不取决于 GRG 的大小。我们还发现，GRGs 和控制样本相对于附近大型结构的位置彼此一致。这些结果表明，GRG 属性与其恒星追踪的环境之间没有相关性，这表明外部星系环境不是无线电结构大尺寸的主要原因。最后，关于无线电反馈，我们表明蓝色卫星的比例与 GRG 属性无关，