The relationship between a galaxy's properties and its circumgalactic medium (CGM) provides a unique view of how galaxies evolve. We present an interesting edge-on (i=86 degrees) disk galaxy (G1547) where the CGM is probed by a background quasar at a distance of 84 kpc and within 10 degrees of the galaxy major axis. G1547 does not have any detectable CGM absorption down to stringent limits, covering HI (EW$_r$ -11$ have HI absorption. We conclude that SSFR is a good indicator of the presence of HI CGM. Interestingly however, G1547 is the only galaxy with log(SSFR/yr$^{-1})>-11$ that has no detectable CGM. Given the properties of G1547, and its absent CGM, it is plausible that G1547 is undergoing quenching due to a lack of accreting fuel for star-formation, with an estimated quenching timescale of $4\pm1$ Gyr. G1547 provides a unique perspective into the external mechanisms that could explain the migration of galaxies into the green valley.

中文翻译：

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由于缺乏环星系介质导致绿色山谷中星系淬灭的证据

星系属性与其环星系介质 (CGM) 之间的关系为星系如何演化提供了独特的视角。我们展示了一个有趣的边缘（i=86 度）盘状星系（G1547），其中 CGM 被背景类星体探测到，距离为 84 kpc，距离星系长轴 10 度以内。G1547 没有任何可检测的 CGM 吸收达到严格的限制，涵盖 HI（EW$_r$ -11$ 具有 HI 吸收。我们得出结论，SSFR 是 HI CGM 存在的良好指标。然而，有趣的是，G1547 是唯一的星系log(SSFR/yr$^{-1})>-11$ 没有可检测到的 CGM。鉴于 G1547 的特性，并且没有 CGM，G1547 有可能由于缺乏吸积燃料而正在淬灭恒星形成，估计淬灭时间尺度为 $4\pm1$ Gyr。