Quasar projected pairs (QPPs) can be used for investigating the circumgalactic medium of quasars through the study of intervening absorption lines in the spectrum of the background quasar that are at the same redshift of the foreground quasar. Here we report on optical spectroscopy, gathered at Gran Telescopio Canarias, of 14 QPPs. In 7 cases we find MgII absorption lines associated with the foreground quasar. Only for two cases line-of-sight absorptions (LOS) are revealed. These new observations complement our previous study performed on other 30 QPPs. A brief discussion of the properties of the intervening absorption lines associated with the foreground quasar for the full dataset is reported.

中文翻译：

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类星体的环绕银河介质：横向和视线吸收

通过研究背景类星体光谱中与前景类星体红移相同的吸收线，类星体投影对（QPP）可用于研究类星体的环绕星系介质。在这里，我们报告了在 Gran Telescopio Canarias 收集的 14 个 QPP 的光谱学。在 7 个案例中，我们发现了与前景类星体相关的 MgII 吸收线。仅在两种情况下会显示视线吸收 (LOS)。这些新观察结果补充了我们之前对其他 30 个 QPP 进行的研究。报告简要讨论了与整个数据集的前景类星体相关的中间吸收线的特性。