论文标题
寻找当地气泡内的温暖气和热气之间的接口
In Search of an Interface between Warm and Hot Gas within the Local Bubble
论文作者
论文摘要
We have examined UV spectra recorded by the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope for three stars, HD32309, 41 Ari, and $η$~Tel, that are located well inside the boundary of the Local Hot Bubble in our search for absorption features of Si IV, C IV, and N V that could reveal the presence of an interface between the local warm ($T\sim 7000$ K)中性介质和更遥远的热（$ t \ sim 10^6 $ k）星际介质。在所有情况下，我们都无法检测到这种离子。我们最有意义的上限是，对于log n（c iv）<11.86，朝向HD32309，这低于穿透导电/蒸发界面或湍流混合层的视线的期望。我们提供了有关这些负面结果的猜想，这是由于其他云通过局部云屏蔽局部云而引起的导电层，这可能会使我们更难感知中等温度下气体的离散吸收特征，或者是由于在本地云表面上大多数位置存在切向磁场。
We have examined UV spectra recorded by the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope for three stars, HD32309, 41 Ari, and $η$~Tel, that are located well inside the boundary of the Local Hot Bubble in our search for absorption features of Si IV, C IV, and N V that could reveal the presence of an interface between the local warm ($T\sim 7000$ K) neutral medium and a more distant hot ($T\sim 10^6$ K) interstellar medium. In all cases, we failed to detect such ions. Our most meaningful upper limit is that for log N(C IV)< 11.86 toward HD32309, which is below the expectation for a sight line that penetrates either a conductive/evaporative interface or a turbulent mixing layer. We offer conjectures on the reasons for these negative results in terms of either a suppression of a conductive layer caused by the shielding of the local cloud by other clouds, which may make it more difficult for us to sense discrete absorption features from gases at intermediate temperatures, or by the presence of a tangential magnetic field at most locations on the surface of the local cloud.
