CAJ | 학술논문

恒星的视向速度对于研究银河系的演化结构和动力学有很重要的意义，同时也是寻找变源和特殊天体的一种手段。不同的研究对其测量精度有不一样的要求。使用模板匹配的方法计算不同类型的低分辨率可见光波段恒星光谱的视向速度精度，从而为不同方面的科学研究提供有效可靠的参考。分别选取不同光谱型高信噪比的美国斯隆巡天恒星光谱，并加以噪声来模拟不同信噪比条件下的恒星光谱。通过分别计算这些恒星样本的视向速度，定量分析了各种类型的恒星在不同信噪比条件下能达到的视向速度测量精度。同时，还就白矮星的视向速度测量精度进行了分析。结果显示，对于相同信噪比的早型恒星的视向速度测量精度远没有晚型恒星的测量精度高，尤其是A型星的视向速度测量标准误差是K型星和M型星的5～8倍。分析其原因，主要是由于不同类型恒星的具有不同宽度的谱线所导致的。因此对于具有更宽谱线的白矮星光谱的视向速度测量误差更大，可达50 km · s-1。以上结论将为恒星科学研究提供很好的参考。
항성적시향속도대우연구은하계적연화결구화동역학유흔중요적의의，동시야시심조변원화특수천체적일충수단。불동적연구대기측량정도유불일양적요구。사용모판필배적방법계산불동류형적저분변솔가견광파단항성광보적시향속도정도，종이위불동방면적과학연구제공유효가고적삼고。분별선취불동광보형고신조비적미국사륭순천항성광보，병가이조성래모의불동신조비조건하적항성광보。통과분별계산저사항성양본적시향속도，정량분석료각충류형적항성재불동신조비조건하능체도적시향속도측량정도。동시，환취백왜성적시향속도측량정도진행료분석。결과현시，대우상동신조비적조형항성적시향속도측량정도원몰유만형항성적측량정도고，우기시A형성적시향속도측량표준오차시K형성화M형성적5～8배。분석기원인，주요시유우불동류형항성적구유불동관도적보선소도치적。인차대우구유경관보선적백왜성광보적시향속도측량오차경대，가체50 km · s-1。이상결론장위항성과학연구제공흔호적삼고。
The radial velocity of the star is very important for the study of the dynamics structure and chemistry evolution of the Milky Way ,is also an useful tool for looking for variable or special objects .In the present work ,we focus on calculating the ra-dial velocity of different spectral types of low-resolution stellar spectra by adopting a template matching method ,so as to provide effective and reliable reference to the different aspects of scientific research .We choose high signal-to-noise ratio (SNR) spectra of different spectral type stellar from the Sloan Digital Sky Survey (SDSS) ,and add different noise to simulate the stellar spectra with different SNR .Then we obtain the radial velocity measurement accuracy of different spectral type stellar spectra at different SNR by employing a template matching method .Meanwhile ,the radial velocity measurement accuracy of white dwarf stars is an-alyzed as well .We concluded that the accuracy of radial velocity measurements of early-type stars is much higher than late-type ones .For example ,the 1-sigma standard error of radial velocity measurements of A-type stars is 5~8 times as large as K-type and M-type stars .We discuss the reason and suggest that the very narrow lines of late-type stars ensure the accuracy of measure-ment of radial velocities ,while the early-type stars with very wide Balmer lines ,such as A-type stars ,become sensitive to noise and obtain low accuracy of radial velocities .For the spectra of white dwarfs stars ,the standard error of radial velocity measure-ment could be over 50 km · s-1 because of their extremely wide Balmer lines .The above conclusion will provide a good reference for stellar scientific study .