揭示双星食变星UU Aqr的X射线特性：空间和光谱分辨的双组分发射

Comparisons of MHD Propeller Model with Observations of Cataclysmic Variable AE Aqr

We have developed a numerical MHD model of the propeller candidate star AE Aqr using axisymmetric magneto-hydrodynamic (MHD) simulations. We suggest that AE Aqr is an intermediate polar-type star, where the magnetic field is relatively weak and an accretion disc may form around the white dwarf. The star is in the propeller regime, and many of its observational properties are determined by the disc-magnetosphere interaction. Comparisons of the characteristics of the observed versus modelled AE Aqr star show that the model can explain many observational properties of AE Aqr. In a representative …

VLA Observations of the AE Aqr-type Cataclysmic Variable LAMOST J024048.51+195226.9

AE Aqr was until recently the only known magnetic cataclysmic variable (MCV) containing a rapidly spinning (33.08 s) white dwarf (WD). Its radio emission is believed to be a superposition of synchrotron emitting plasmoids, because it has a positive spectral index spanning three orders of magnitude (~2-2000 GHz) and is unpolarized. Both characteristics are unusual for MCVs. Recently, Thorstensen has suggested that the cataclysmic variable LAMOST J024048.51+195226.9 (henceforth, J0240+19) is a twin of AE Aqr based on its optical spectra. Optical photometry shows the star to be a high-inclination…

The cataclysmic variable AE Aquarii: B-V colour of the flares

We report simultaneous observations of the flaring behaviour of the cataclysmic variable star AE Aqr. The observations are in Johnson B and V bands. The colour-magnitude diagrams (B-V versus V and B-V vs. B) show that the star becomes blues as it becomes brighter. In our model AE Aqr behaviour can be explained with flares (fireballs) with 0.03 < B-V < 0.30 and temperature in the interval 8000 < T < 12000.

AE宝瓶座是激变变星的一个新的子类

AE Aquarii represents a new subclass of Cataclysmic Variables

我们分析了独特的新星般的明星AE宝瓶座确定了一个紧密的双星系统包含一个红矮星和一个非常快速旋转的磁化白矮星的属性。它不能被归类为激变变星的三个通常被采用的子类：极星、中极星和吸积非磁化白矮星。我们的研究表明，AE Aqr中的白矮星处于喷射状态，其磁矩为$μ~ 1.5 \times 10^{34} G cm^3$。它之所以转变成这种状态，是因为在前一个纪元中，系统组件之间发生了密集的质量交换。白矮星表面的高速率吸积盘导致了其磁场的暂时屏蔽，并使白矮星的自旋加速到目前的自旋周期。白矮星到喷射状态的转变发生在自旋上升时期的最后阶段，因为它的磁场由于扩散而从吸积的等离子体中出现。在这个场景的框架中，AE Aqr代表了北极星进化链中缺失的一环，而白矮星类似于一颗回收的脉冲星。

Search for gamma-ray emission from AE Aquarii with seven years of FERMI-LAT observations

AE Aquarii (AE Aqr) is a cataclysmic binary hosting one of the fastest rotating (P$_{\rm spin}$ = 33.08 s) white dwarfs known. Based on seven years of Fermi Large Area Telescope (LAT) Pass 8 data, we report on a deep search for gamma-ray emission from AE Aqr. Using X-ray observations from ASCA, XMM-Newton, Chandra, Swift, Suzaku, and NuSTAR, spanning 20 years, we substantially extend and improve the spin ephemeris of AE Aqr. Using this ephemeris, we searched for gamma-ray pulsations at the spin period of the white dwarf. No gamma-ray pulsations were detected above 3 $σ$ significance. Neither p…

关于奇异激变变星AE宝瓶座的起源

On the origin of the peculiar cataclysmic variable AE Aquarii

宝瓶座AE是一个包含红矮星和磁化白矮星的近距离双星系统，自转周期为33秒。白矮星的短自旋周期是由系统各组成部分在前一个纪元中的强烈质量交换引起的。我们发现，一个高速率的磁盘吸积到白矮星表面导致临时屏蔽其磁场和自旋的白矮星到目前的自旋周期。白矮星到喷射状态的转变发生在自旋上升时期的最后阶段，在它的磁场由于扩散而从吸积的等离子体中出现之后。在这个场景的框架中，AE Aqr代表了北极星进化链中缺失的一环，而白矮星类似于一颗回收的脉冲星。