基于多分辨率融合距离的低质量星系光谱红移测量方法
发布时间：2019-06-28 15:02
【摘要】：星系光谱红移测量是大规模天体光谱巡天项目中的一个重要研究内容,其目的是从在光谱中测量出对应星系由于多普勒效应引起的红移。随着银河系外巡天项目的开展,观测目标距离(红移)越来越远,其星等越来越暗,光谱的质量也随之越来越差,如何能够有效准确地从这些低质量的光谱测量出红移是河外巡天面临的一个重要问题。基于此问题,充分考虑到低质量星系光谱的特点及数据特征,新定义了一种针对低质量巡天光谱数据的多分辨率融合距离,以此为基础提出一种针对低质量星系光谱的红移测量方法。该方法充分结合不同分辨率下光谱的特征,计算距离时首先将模板光谱和待测光谱同时降到多个相同分辨率下,该分辨率下所有波长采样点都计算一个偏差进而得到一个距离,然后将多个分辨率下得到的距离通过加权得到一个融合距离。基于多分辨率融合距离提出的星系红移测量方法,能够有效的解决低质量星系光谱的红移无法准确测量的问题。研究了不同信噪比下红移测量的精度,在信噪比大于5之后,该方法测量准确率可以达到90%以上。大量实验表明,提出的方法在星系光谱质量较低的情况可以非常准确地从中测量出红移,测量误差和红移大小无关,可以很好地应用于大规模巡天数据的星系光谱红移测量中。
[Abstract]:The red shift measurement of galaxy spectrum is an important research content in the large-scale celestial spectral survey project, the purpose of which is to measure the red shift of the corresponding galaxy caused by Doppler effect from the spectrum. With the development of the extragalactic survey project, the distance (red shift) of the observation target is getting farther and farther, its magnitude is getting darker and darker, and the quality of the spectrum is getting worse and worse. How to effectively and accurately measure the red shift from these low quality spectra is an important problem facing the extragalactic sky survey. Based on this problem, considering the characteristics and data characteristics of low mass galaxy spectrum, a new multi-resolution fusion distance for low quality sky survey spectral data is defined, and a red shift measurement method for low mass galaxy spectrum is proposed. This method fully combines the characteristics of the spectrum at different resolutions. When calculating the distance, the template spectrum and the spectrum to be measured are reduced to more than one resolution at the same time. At this resolution, all the wavelength sampling points calculate a deviation and get a distance, and then the distance obtained at multiple resolutions is weighted to get a fusion distance. The proposed method based on multi-resolution fusion distance can effectively solve the problem that the redshift of low-mass galaxy spectrum can not be measured accurately. The accuracy of red shift measurement under different signal-to-noise ratios is studied. when the signal-to-noise ratio is greater than 5, the accuracy of the method can reach more than 90%. A large number of experiments show that the proposed method can be used to measure the red shift very accurately in the case of low spectral mass of the galaxy, and the measurement error is independent of the red shift, and can be well applied to the measurement of the red shift of the galaxy spectrum with large-scale sky patrol data.
【作者单位】： 山东大学(威海)机电与信息工程学院;中国科学院光学天文重点实验室国家天文台;烟台大学计算机与控制工程学院;
【基金】：国家自然科学基金项目(U1431102,11473019,11303036)资助
【分类号】：P141.5
，
本文编号：2507388
[Abstract]:The red shift measurement of galaxy spectrum is an important research content in the large-scale celestial spectral survey project, the purpose of which is to measure the red shift of the corresponding galaxy caused by Doppler effect from the spectrum. With the development of the extragalactic survey project, the distance (red shift) of the observation target is getting farther and farther, its magnitude is getting darker and darker, and the quality of the spectrum is getting worse and worse. How to effectively and accurately measure the red shift from these low quality spectra is an important problem facing the extragalactic sky survey. Based on this problem, considering the characteristics and data characteristics of low mass galaxy spectrum, a new multi-resolution fusion distance for low quality sky survey spectral data is defined, and a red shift measurement method for low mass galaxy spectrum is proposed. This method fully combines the characteristics of the spectrum at different resolutions. When calculating the distance, the template spectrum and the spectrum to be measured are reduced to more than one resolution at the same time. At this resolution, all the wavelength sampling points calculate a deviation and get a distance, and then the distance obtained at multiple resolutions is weighted to get a fusion distance. The proposed method based on multi-resolution fusion distance can effectively solve the problem that the redshift of low-mass galaxy spectrum can not be measured accurately. The accuracy of red shift measurement under different signal-to-noise ratios is studied. when the signal-to-noise ratio is greater than 5, the accuracy of the method can reach more than 90%. A large number of experiments show that the proposed method can be used to measure the red shift very accurately in the case of low spectral mass of the galaxy, and the measurement error is independent of the red shift, and can be well applied to the measurement of the red shift of the galaxy spectrum with large-scale sky patrol data.
【作者单位】： 山东大学(威海)机电与信息工程学院;中国科学院光学天文重点实验室国家天文台;烟台大学计算机与控制工程学院;
【基金】：国家自然科学基金项目(U1431102,11473019,11303036)资助
【分类号】：P141.5
，
本文编号：2507388
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