盾牌座δ型脉动变星的星震学研究

发布时间：2018-05-03 09:24

本文选题：盾牌座δ型变星 + 星震学　；参考：《中国科学院大学(中国科学院云南天文台)》2017年博士论文

【摘要】：盾牌座δ型脉动变星上存在丰富的振动模式,既有径向振动模式又有非径向振动模式.不同的振动模式携有恒星内部不同的结构信息,故盾牌座δ型变星是星震学理想的研究对象.本文中,我们对三颗盾牌座δ型变星HD 50844,CoRoT102749568,以及EE Cam进行了星震学分析,并获得了一些非常有意义的结果.HD 50844的脉动现象是在2005年被发现的.2014年,Balona分析CoRoT测光序列共获得59个可靠的振动频率.本文中,我们更关心频率值大于75μHz的40个振动模式.从这40个振动频率中,我们一共发现了13组可能的自转分裂多重线.其中有2组完整的自转分裂三重线,1组不完整的自转分裂三重线,7组不完整的自转分裂五重线,和3组不完整的自转分裂七重线.根据这些自转分裂值,我们计算得到HD 50844的自转周期为2.44+0.13-0.08天.通过用模型计算频率拟合三个m=0的非径向振动模式f11,f22,和f29和一个径向基频模式f4,我们确定了HD 50844的基本参数:M=1.81±0.01 M⊙,Z=0.008±0.001,Teff=7508±125 K,log g=3.658±0.004,R=3.300±0.023 R⊙,L=30.98±2.39L⊙.除此之外,我们发现大部分观测频率属于混合模式.非径向振动模式f11,f22,和f29在恒星包层有p模式的传播特征,同时它们在恒星氦核兼有显著的g模式特性.而径向基频模式f4主要在恒星包层内传播,携带的是恒星包层的结构信息.这些特点要求理论模型的恒星包层和氦核都要与真实情况相匹配.最终我们得到了HD 50844的氦核大小MHe=0.173±0.004 M⊙和RHe=0.068±0.001R⊙.2013年,Papar¨o等人公布了他们对CoRoT 102749568的分析结果,共得到52个独立的振动频率.我们从中发现4组l=1模式的自转分裂多重线,9组l=2模式的自转分裂多重线,和8组l=3模式的自转分裂多重线.尤其,这些自转分裂多重线中有三组完整的三重线,他们分别是(f10,f12,f14),(f31,f34,f35),和(f41,f43,f44).根据这些自转分裂值,我们确定了CoRoT 102749568的自转周期Prot=1.34+0.04-0.05天.模型拟合结果表明CoRoT 102749568是一颗主序后恒星,其基本参数为:M=1.54±0.03 M⊙,Z=0.006,fov=0.004±0.002,log g=3.696±0.003,Teff=6886±70 K,R=2.916±0.039 R⊙,and L=17.12±1.13L⊙.与HD 50844类似,CoRoT 102749568的大部分观测频率也属于混合模式.基于非径向振动模式(f12,f34,f43)及径向模式f13的振动特征,我们得到了CoRoT102749568的氦核大小MHe=0.148±0.003 M⊙和RHe=0.0581±0.0007 R⊙.EE Cam的脉动现象是在1997年被发现的.Breger等人自2006年到2010年对其进行了测光观测,获得了300+晚上的测光数据.从这300+晚上的测光数据中,Breger等人共提取了37个独立的振动频率.我们从中发现5组l=1模式的自转分裂,10组l=2模式的自转分裂.仅仅用l=0,1,2模式就可以解释EE Cam的频率谱,这和HD 50844和CoRoT 102749568有很大的不同.基于这些自转分裂,我们计算得到了EE Cam的自转周期为Prot=1.84+0.07-0.05天.通过用计算频率与观测频率进行拟合匹配,我们找到了一个最佳匹配的恒星模型,其物理参数为:M=2.04 M⊙,Z=0.028,Teff=6433 K,log L/L⊙=1.416,R=4.120 R⊙,log g=3.518.基于最佳拟合模型,我们发现非径向振动模式f11和f32属于混合模式,它们在恒星包层有p模式的传播特征,同时它们在恒星氦核兼有显著地g模式特征.而径向基频模式f1主要在恒星包层内传播,它携带的是恒星包层的结构信息.最后,我们得到了EE Cam的氦核大小MHe=0.181 M⊙和RHe=0.0796 R⊙.
[Abstract]:There are abundant vibration modes on the delta type pulsating variable star of the shield, which have both radial vibration mode and non radial vibration mode. Different vibration modes carry different structural information inside the star, so the shield delta variable star is the object of the study of the ideal of the star seismology. In this paper, we have three delta variable stars HD 50844, CoRoT102749568, And EE Cam carried out the analysis of the star seismology, and obtained some very meaningful results of the pulsation of.HD 50844, which was found in 2005. The Balona analysis CoRoT photometric sequence obtained a total of 59 reliable vibration frequencies. In this paper, we are more concerned with the 40 vibration modes of the frequency value greater than 75 mu Hz. From these 40 vibrational frequencies, we are concerned. A total of 13 groups of possible spontaneous mitotic multiple lines were found. There were 2 groups of complete rotation split three lines, 1 incomplete rotation split three lines, 7 incomplete rotation split five lines, and 3 groups of incomplete rotation splitting seven lines. According to these rotation splitting values, the rotation period of HD 50844 was calculated to be 2.44+0.13-0.08 By using the model to calculate the non radial vibration modes of three m=0, F11, F22, and f29 and a radial fundamental frequency mode F4, we determine the basic parameters of HD 50844: M=1.81 + 0.01 M, Z=0.008 + 0.001, Teff=7508 + 125 K, log 0.004, + 0.023. The frequency of the measurement is a mixed mode. The non radial vibration modes F11, F22, and f29 have the propagation characteristics of the P mode in the stellar cladding, and they have a significant G mode characteristic in the helium nucleus of the star. The radial fundamental frequency mode F4 is mainly propagating in the stellar cladding and carrying the structural information of the stellar cladding. These characteristics require the stellar cladding of the theoretical model. And the helium core should be matched with the true condition. Finally, we got the HD 50844 helium core size MHe=0.173 + 0.004 M and RHe=0.068 + 0.001R.2013 years. Papar & O and others published their analysis results to CoRoT 102749568. We got 52 independent vibrational frequencies. We present 4 groups of l=1 modes of the split multiple lines, 9 l=2. The split multiple lines of the mode, and the 8 groups of l=3 modes of the split multiple lines. In particular, there are three sets of complete three lines in these split multiple lines, they are (F10, F12, F14), (f31, F34, F35), and (F41, F43, f44). According to these rotation splitting values, we determine the rotation of CoRoT 102749568 for the cycle of Prot=1.34+0.04-0.05 days. The fitting results show that CoRoT 102749568 is a star after main sequence, and its basic parameters are M=1.54 + 0.03 M, Z=0.006, fov=0.004 + 0.002, log g=3.696 + 0.003, Teff=6886 + 70 K, R=2.916 + 0.039 R. Similar to 50844, the large part of the observed frequency of 102749568 is based on the non radial vibration. The vibration characteristics of the mode (F12, F34, F43) and radial mode f13, we have obtained the pulsation phenomenon of the CoRoT102749568 helium size MHe=0.148 + 0.003 M and RHe=0.0581 + 0.0007 R.EE Cam, which were found in 1997 from 2006 to 2010. In the evening photometry data, Breger and others extracted 37 independent vibrational frequencies. We found 5 groups of l=1 mode rotation splitting and 10 groups of l=2 mode spin splitting. The frequency spectrum of EE Cam can be explained by only l=0,1,2 mode, which is very different from HD 50844 and CoRoT 102749568. Based on these spin splitting, we calculate The rotation period of EE Cam is Prot=1.84+0.07-0.05 days. By fitting the calculated frequency with the observed frequency, we find a best matching star model. The physical parameters are M=2.04 M, Z=0.028, Teff=6433 K, log L/L, =1.416, and based on the best fitting model, we find non radial. The vibration modes F11 and F32 belong to the mixed mode, which have the propagation characteristics of the P pattern in the stellar cladding, and they have a significant g pattern in the helium nucleus of the star. And the radial fundamental frequency mode F1 is propagating mainly in the stellar cladding, which carries the structural information of the stellar cladding. Finally, we get the EE Cam's helium core size MHe=0.181 M M And RHe=0.0796 R.

【学位授予单位】：中国科学院大学(中国科学院云南天文台)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P15

【相似文献】