【摘要】：星系光譜紅移測量是大規(guī)模天體光譜巡天項目中的一個重要研究內(nèi)容,其目的是從在光譜中測量出對應(yīng)星系由于多普勒效應(yīng)引起的紅移。隨著銀河系外巡天項目的開展,觀測目標距離(紅移)越來越遠,其星等越來越暗,光譜的質(zhì)量也隨之越來越差,如何能夠有效準確地從這些低質(zhì)量的光譜測量出紅移是河外巡天面臨的一個重要問題�；诖藛栴},充分考慮到低質(zhì)量星系光譜的特點及數(shù)據(jù)特征,新定義了一種針對低質(zhì)量巡天光譜數(shù)據(jù)的多分辨率融合距離,以此為基礎(chǔ)提出一種針對低質(zhì)量星系光譜的紅移測量方法。該方法充分結(jié)合不同分辨率下光譜的特征,計算距離時首先將模板光譜和待測光譜同時降到多個相同分辨率下,該分辨率下所有波長采樣點都計算一個偏差進而得到一個距離,然后將多個分辨率下得到的距離通過加權(quán)得到一個融合距離。基于多分辨率融合距離提出的星系紅移測量方法,能夠有效的解決低質(zhì)量星系光譜的紅移無法準確測量的問題。研究了不同信噪比下紅移測量的精度,在信噪比大于5之后,該方法測量準確率可以達到90%以上。大量實驗表明,提出的方法在星系光譜質(zhì)量較低的情況可以非常準確地從中測量出紅移,測量誤差和紅移大小無關(guān),可以很好地應(yīng)用于大規(guī)模巡天數(shù)據(jù)的星系光譜紅移測量中。
[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.
【作者單位】： 山東大學(xué)(威海)機電與信息工程學(xué)院;中國科學(xué)院光學(xué)天文重點實驗室國家天文臺;煙臺大學(xué)計算機與控制工程學(xué)院;
【基金】：國家自然科學(xué)基金項目(U1431102,11473019,11303036)資助
【分類號】：P141.5
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本文編號：2507388