目标。在极地的发射线显示复杂的配置文件,具有多个组件,通常归因于吸积流,线程区,吸积点,和照射的次级恒星。在低态极化中,吸积流和吸积斑的贡献率大大降低,这为研究次级星辐射或恒星活动的影响提供了机会。我们观察VV Pup在一个特殊的低状态,研究和限制的线形成区域的属性,并寻找色球活动和/或辐射的证据。方法.我们在ESO VLT+ FORS 1获得了相位分辨光谱,目的是分析发射线轮廓和径向速度作为轨道周期的函数。我们还量身定制的辐照次级恒星模型,比较预测和观察到的发射线,并建立线形成区域的性质。结果我们的观察和数据分析,当与模型相结合的辐照的二次星,表明,虽然弱的低电离金属线(FeI和MgI)可能是一致的辐照过程,占主导地位的巴耳末H的发射线,以及NaI和HeI,不能再现的辐照的二次星模型。我们赞成作为主要的形成区域和观测到的H,碘化钠,和他的发射线的原因,虽然一个线程区域非常接近L1点不能被排除。
英文摘要:
Aims. Emission lines in polars show complex profiles with multiple components that are typically ascribed to the accretion stream, threading region, accretion spot, and the irradiated secondary-star. In low-state polars the fractional contribution by the accretion stream, and the accretion spot is greatly reduced offering an opportunity to study the effect of the secondary-star irradiation or stellar activity. We observed VV Pup during an exceptional low-state to study and constrain the properties of the line-forming regions and to search for evidence of chromospheric activity and/or irradiation. Methods. We obtained phase-resolved optical spectra at the ESO VLT+FORS1 with the aim of analyzing the emission line profile and radial velocity as a function of the orbital period. We also tailored irradiated secondary-star models to compare the predicted and the observed emission lines and to establish the nature of the line-forming regions. Results. Our observations and data analysis, when combined with models of the irradiated secondary-star, show that, while the weak low ionization metal lines (FeI and MgI) may be consistent with irradiation processes, the dominant Balmer H emission lines, as well as NaI and HeI, cannot be reproduced by the irradiated secondary-star models. We favor the secondary-star chromospheric activity as the main forming region and cause of the observed H, NaI, and He emission lines, though a threading region very close to the L1 point cannot be excluded.
On the Role of Irradiation and Evaporation in Strongly Irradiated Accretion Disks in the Black Hole X-ray Binaries: Toward an Understanding of FREDs and Secondary Maxima
我们研究了一个新的范例来解释在一些明亮的X射线新星的光变曲线中看到的指数衰减。这些系统在软X射线中表现出指数衰减,e折叠时间常数为~30 d。我们调查的情况下,物质蒸发成日冕是占主导地位的质量去除机制的吸积盘。我们利用的热蒸发的不稳定性发现的Szerov和Wehrse。首先,我们参数化本地质量损失率从磁盘(安装到垂直结构计算的光学薄结构使用光电离代码云),然后我们利用我们的数值时间依赖模型的衰变的缩放。通过调节蒸发的强度,可以产生衰变的~30 d e折叠时标和X射线nova光变曲线中出现的~1-3 d快速上升的次极大值。
Mass Determination and Detection of the Onset of Chromospheric Activity for the Sub-Stellar Object in EF Eridani
EF Eri是一个磁激变变星,在过去的九年里一直处于低吸积状态。低态光谱揭示了潜在的塞曼分裂白矮星吸收线。这些特征用于确定白矮星的场强值为13-14 MG。最近,5-7年进入低态,巴末等发射谱线已出现在光学上。H $α$发射线的分析产生了EF Eri的第一个径向速度解,导致了二进制的光谱星历,并使用最好的白矮星质量为0.6 M ${\odot}$,质量估计为0.055 M ${\odot}$的二次。当白矮星的质量为0.95 M ${\odot}$(磁性白矮星的平均质量)时,次级质量增加到0.087 M ${\odot}$。在EF Eri的轨道周期为81分钟时,这颗质量更高的次级恒星不可能是一颗正常的恒星,但仍然适合在洛希叶内。确认了Balmer谱线和其它谱线的来源是亚恒星次级辐射,并认为这是恒星活动的结果。我们比较了EF Eri的发射线光谱和活动行为,最近在AM Her和VV Pup中观察到的,并归因于恒星活动。我们探索最初为V471 Tau,RS CVn双星和太阳系外行星开发的观测和模型。我们的结论是,辐射的二次在EF Eri和类似的系统是不可能的,在两极,两颗恒星之间的磁场相互作用(与可能的潮汐分量)是一个可能的机制,这将集中色球活动的次级附近的亚恒星点的白矮星。