Flux calibration of medium-resolution spectra from 300 nm to 2500 nm: Model reference spectra and telluric correction
Flux calibration of medium-resolution spectra from 300 nm to 2500 nm: Model reference spectra and telluric correction
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DOI：
10.1051/0004-6361/201423790
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发表时间：
2014-08
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影响因子：
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通讯作者：
S. Moehler;A. Modigliani;W. Freudling;Noemi Giammichele;Alexandros Gianninas;A. Gonneau;W. Kausch;Ariane Lançon;Stefan Noll;Thomas Rauch;J. Vinther
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文献类型：
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作者：
S. Moehler;A. Modigliani;W. Freudling;Noemi Giammichele;Alexandros Gianninas;A. Gonneau;W. Kausch;Ariane Lançon;Stefan Noll;Thomas Rauch;J. Vinther
虽然近红外波长范围对天体物理学越来越重要，但明显缺乏分光光度标准星星数据，无法对这些数据进行通量校准。此外，即使在光学波长范围内，通量校准中高分辨率中阶梯光栅光谱数据也具有挑战性，因为可用的通量标准数据通常过于粗糙。我们将提供标准的星星参考数据，使用户能够获得从300 nm到2500 nm的响应曲线，用于中高分辨率的光谱数据，包括使用中阶梯光栅光谱仪拍摄的光谱数据。此外，我们描述了一种方法来纠正中等的大地吸收，而不需要观察大地标准星。作为通量标准星的参考数据，我们使用来自恒星模型大气的理论光谱。我们验证，他们提供了一个适当的描述所观察到的标准星星光谱检查残差线核心和线重叠区域的比率观察到的（X-射手）光谱模型光谱。最后选择的模型光谱，然后校正剩余的失配和光度校准使用独立的观察。我们提供了六颗南方通量标准星的新的、精细采样的参考光谱，允许用户对300 ~ 2500 nm的数据进行通量校准，并提出了一种利用大气模型校正碲吸收的方法。
While the near-infrared wavelength regime is becoming more and more important for astrophysics there is a marked lack of spectrophotometric standard star data that would allow the flux calibration of such data. Furthermore, flux calibrating medium- to high-resolution \'echelle spectroscopy data is challenging even in the optical wavelength range, because the available flux standard data are often too coarsely sampled. We will provide standard star reference data that allow users to derive response curves from 300nm to 2500nm for spectroscopic data of medium to high resolution, including those taken with \'echelle spectrographs. In addition we describe a method to correct for moderate telluric absorption without the need of observing telluric standard stars. As reference data for the flux standard stars we use theoretical spectra derived from stellar model atmospheres. We verify that they provide an appropriate description of the observed standard star spectra by checking for residuals in line cores and line overlap regions in the ratios of observed (X-shooter) spectra to model spectra. The finally selected model spectra are then corrected for remaining mismatches and photometrically calibrated using independent observations. The correction of telluric absorption is performed with the help of telluric model spectra.We provide new, finely sampled reference spectra without telluric absorption for six southern flux standard stars that allow the users to flux calibrate their data from 300 nm to 2500 nm, and a method to correct for telluric absorption using atmospheric models.