论文标题
银河灭绝法律：ii。隐藏在朴素的视线中，一个新的星际吸收带，比任何已知的dib宽7700Å
Galactic extinction laws: II. Hidden in plain sight, a new interstellar absorption band at 7700 Å broader than any known DIB
论文作者
论文摘要
我们已经检测到一个宽阔的星际吸收带，中心接近7700Å，而FWHM为176.6 $ \ pm $ 3.9。这是在光学范围内检测到的第一个吸收带，并且比众多漫射的星际条带（DIB）明显宽。到目前为止，它仍未发现，因为它部分隐藏在o $ _2 $生产的tranuric乐队后面。使用stis@HST光谱发现了该频段，后来在大量不同类型的恒星（OB恒星，BA Supergiants，Red Giants）的恒星中检测到了频段。测量频带的EW，并将其与我们的灭绝和KI $λλ$ 7667.021,7701.093测量同一样品的测量值。该载体在弥漫性和半透明的银河系中无处不在，但在OB恒星周围的环境中耗尽。特别是，它似乎不存在或几乎在富含分子碳的视线中。这种行为类似于$σ$ -Type Dibs的行为，该行为起源于低/中密度紫外线暴露的ISM，但在高密度紫外线屏蔽的分子云中耗尽。我们还提供了有关以前有关$ e（4405-5495）$和$ r_ {5495} $之间关系的工作的最新信息，并将我们的结果纳入ISM的一般模型。
We have detected a broad interstellar absorption band centred close to 7700 Å and with a FWHM of 176.6$\pm$3.9 Å. This is the first such absorption band detected in the optical range and is significantly wider than the numerous diffuse interstellar bands (DIBs). It remained undiscovered until now because it is partially hidden behind the A telluric band produced by O$_2$. The band was discovered using STIS@HST spectra and later detected in a large sample of stars of diverse type (OB stars, BA supergiants, red giants) using further STIS and ground-based spectroscopy. The EW of the band is measured and compared with our extinction and K I $λλ$7667.021,7701.093 measurements for the same sample. The carrier is ubiquitous in the diffuse and translucent Galactic ISM but is depleted in the environment around OB stars. In particular, it appears to be absent or nearly so in sightlines rich in molecular carbon. This behaviour is similar to that of the $σ$-type DIBs, which originate in the low/intermediate-density UV-exposed ISM but are depleted in the high-density UV-shielded molecular clouds. We also present an update on our previous work on the relationship between $E(4405-5495)$ and $R_{5495}$ and incorporate our results into a general model of the ISM.
