AI 中文总结
研究对距离太阳20秒差距内四个PCEB系统中的白矮星进行直接探测，通过获取光谱拟合模型得到温度等参数，更新了白矮星空间密度，还发现G 203 - 47未潮汐锁定，结果与BPASS框架模型吻合，为双星演化理论研究提供了重要数据。
AI 中文摘要
表征包含白矮星和主序伴星的后共包层双星（PCEB）对于改进双星演化理论至关重要。本文首次直接光谱确认了距离太阳20秒差距内四个PCEB系统（G 203 - 47、GJ 207.1、LHS 1817和Wolf 1130）中的白矮星成分。通过哈勃太空望远镜上的STIS获取近紫外光谱，拟合白矮星模型和M矮星代理光谱，得到白矮星有效温度估计值在约5300 K至6300 K之间。与仅用测光法建模确定的参数比较，因发射特征有5% - 8%的差异。27年后确认G 203 - 47存在白矮星，它是距太阳第九近的白矮星。利用Swift XRT数据发现，尽管G 203 - 47轨道周期为1`4.9天，但未潮汐锁定，自转周期可能超100天，是通过短暂共包层相互作用形成的长周期PCEB的罕见例子。更新了本地白矮星空间密度为(5.2 ± 0.4) × 10⁻³ pc⁻³，并与二元种群和光谱合成（BPASS）框架模型比较，结果与20秒差距内PCEB的预测和观测数量吻合良好。
英文摘要
Characterising post-common envelope binaries (PCEBs) containing a white dwarf and a main-sequence companion is essential for improving theories of binary evolution. This paper presents the first direct spectroscopic confirmations of the white dwarf components in four PCEB systems within 20 pc of the Sun: G 203-47, GJ 207.1, LHS 1817, and Wolf 1130. To detect the white dwarfs we obtained near-UV spectroscopy from STIS on the Hubble Space Telescope, fitting with white dwarf models and M dwarf proxy spectra. We provide estimates of the white dwarf effective temperatures, which range from approximately 5300 K to 6300 K. We compare these parameters to those determined from modelling with photometry alone, and find a 5 - 8 per cent discrepancy, due to emission features. Notably, 27 years after its initial detection, we confirm the presence of a white dwarf in G 203-47, which is the ninth closest white dwarf to the Sun. Using Swift XRT data, we find that despite the 14.9-day orbital period of G 203-47, it is not tidally locked, possessing a rotation period likely exceeding 100 days, and making it a rare example of a long-period PCEB formed via a brief common envelope interaction. We update the local white dwarf space density to (5.2 $\pm $0.4) $\times$ 10$^{-3}$ pc$^{-3}$, and compare our results to models from the Binary Populations and Spectral Synthesis (BPASS) framework, finding a good agreement with the predicted and observed numbers of PCEBs within 20 pc.
Comments11 pages, 7 figures, plus appendix. Published in MNRAS 2026-07-14
