附近的行星托管不活跃的中M矮星LHS 3844的高能光谱
The high-energy spectrum of the nearby planet-hosting inactive mid-M dwarf LHS 3844
摘要：
为了充分描述类地系外行星的大气层，或者缺乏大气层，我们必须包括它们的宿主恒星提供的高能环境。附近的中M矮星LHS 3844拥有一个缺乏实质大气的地球。本文给出了LHS 3844在1131- 3215 A范围内的时间序列紫外光谱。我们在FUV中探测到一个耀斑，其绝对能量为8.96+/-0.79e28 erg，等效持续时间为355+/-31 s。我们分别提取耀斑和静止紫外光谱。对于每个光谱，我们使用紫外线强度之间的相关性来估计Ly-alpha通量。我们使用Swift-XRT的软X射线通量的上限，并构建了一个差分发射模型（DEM）来估计通量被星际介质遮蔽。我们比较的DEM通量估计在XUV的其他方法，依赖于缩放的Ly-alpha，Si IV，和NV线在UV。LHS 3844的XUV，FUV和NUV通量相对于其热光度分别为log 10（Lband/LBol）=-3.65，-4.16和-4.56，对于静态。这些值与MUSCLES调查发现的早期M矮星样本的高能通量作为恒星有效温度的函数的趋势一致。许多光谱上最容易接近的类地系外行星都围绕着不活跃的M中晚期矮星，如LHS 3844。M矮星的高能光谱测量对于系外行星的特征描述是更好的，但并不总是可能的。LHS 3844的光谱是这些世界当前辐射环境的有用代理。
英文摘要：
To fully characterize the atmospheres, or lack thereof, of terrestrial exoplanets we must include the high-energy environments provided by their host stars. The nearby mid-M dwarf LHS 3844 hosts a terrestrial world which lacks a substantial atmosphere. We present a time series UV spectrum of LHS 3844 from 1131-3215A captured by HST/COS. We detect one flare in the FUV, which has an absolute energy of 8.96+/-0.79e28 erg and an equivalent duration of 355+/-31 s. We extract the flare and quiescent UV spectra separately. For each spectrum we estimate the Ly-alpha flux using correlations between UV line strengths. We use Swift-XRT to place an upper limit on the soft X-ray flux and construct a differential emission model (DEM) to estimate flux that is obscured by the interstellar medium. We compare the DEM flux estimates in the XUV to other methods that rely on scaling from the Ly-alpha, Si IV, and N V lines in the UV. The XUV, FUV, and NUV flux of LHS 3844 relative to its bolometric luminosity is log10(Lband/LBol) = -3.65, -4.16, and -4.56, respectively, for the quiescent state. These values agree with trends in high-energy flux as a function of stellar effective temperature found by the MUSCLES survey for a sample of early-M dwarfs. Many of the most spectroscopically accessible terrestrial exoplanets orbit inactive mid- to late-M dwarfs like LHS 3844. Measurements of M dwarf high-energy spectra are preferable for exoplanet characterization, but are not always possible. The spectrum of LHS 3844 is a useful proxy for the current radiation environment for these worlds.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
