论文标题
X射线二进制分类的机器学习方法的比较研究
A Comparative Study of Machine Learning Methods for X-ray Binary Classification
论文作者
论文摘要
X射线二进制文件(XRB)由一个紧凑的物体组成,该物体从轨道的次级恒星中吸收材料。我们确定紧凑对象是否是黑洞的最安全方法是确定其质量:这仅限于明亮的物体,需要大量的时间密集型光谱监测。随着新的X射线源被不同的X射线观测器发现,开发有效,可靠的方法来对紧凑的对象进行分类变得越来越重要。我们比较三种机器学习分类方法(贝叶斯高斯过程(BGP),K-Nearest邻居(KNN),支持向量机(SVM))在XRB系统中确定紧凑物体为中子星或黑洞(BHS)。每种机器学习方法都使用3D颜色强度图中相同类型的系统之间存在的空间模式。我们使用了使用Maxi/GSC的六年数据提取的LightCurves,用于44个代表性来源。我们发现,所有三种方法在区分脉冲与95 \%NPN和100 \%PULSAR的非脉冲中子恒星(NPN)方面均高度准确。所有三种方法都具有很高的精度,将BHS与脉冲星(92 \%)区分开,但继续将BHS与NPN的子类(称为毛毛机)混淆,而KNN只能以50 \%的准确性来预测BHS。这三种方法的精度均高,在5-10个独立运行中提供了等效结果。在以后的工作中,我们建议将第四维度纳入,以减轻BHS与助学金的混乱。这项工作为更强大的方法铺平了道路,以有效区分BHS,NPN和PULSARS。
X-ray Binaries (XRBs) consist of a compact object that accretes material from an orbiting secondary star. The most secure method we have for determining if the compact object is a black hole is to determine its mass: this is limited to bright objects, and requires substantial time-intensive spectroscopic monitoring. With new X-ray sources being discovered with different X-ray observatories, developing efficient, robust means to classify compact objects becomes increasingly important. We compare three machine learning classification methods (Bayesian Gaussian Processes (BGP), K-Nearest Neighbors (KNN), Support Vector Machines (SVM)) for determining the compact objects as neutron stars or black holes (BHs) in XRB systems. Each machine learning method uses spatial patterns which exist between systems of the same type in 3D Color-Color-Intensity diagrams. We used lightcurves extracted using six years of data with MAXI/GSC for 44 representative sources. We find that all three methods are highly accurate in distinguishing pulsing from non-pulsing neutron stars (NPNS) with 95\% of NPNS and 100\% of pulsars accurately predicted. All three methods have high accuracy distinguishing BHs from pulsars (92\%) but continue to confuse BHs with a subclass of NPNS, called the Bursters, with KNN doing the best at only 50\% accuracy for predicting BHs. The precision of all three methods is high, providing equivalent results over 5-10 independent runs. In a future work, we suggest a fourth dimension be incorporated to mitigate the confusion of BHs with Bursters. This work paves the way towards more robust methods to efficiently distinguish BHs, NPNS, and pulsars.