标题： 法布里-珀罗干涉仪的波长自校准和天空减除：OSIRIS的应用 显示英文标题

标题： Wavelength Self-Calibration and Sky Subtraction for Fabry-Perot Interferometers: Applications to OSIRIS

摘要： 我们描述了有关波长校准和天空减除的技术，以最大化可调滤光仪仪器数据的科学效用。 虽然我们特别关注来自光学成像和低分辨率积分光谱仪（OSIRIS）的数据，该仪器安装在10.4米的Gran Telescopio Canarias望远镜上，但我们的讨论可以推广到其他可调滤光仪仪器的数据。 我们方法的一个关键方面是对极坐标变换的使用，当可调滤光仪数据在光学中心周围呈现圆形对称时，这会简化问题。 首先，我们提出了一种利用OH天空发射环来校正波长校准误差的方法。使用此技术，我们将绝对波长校准的精度从5埃提高到1埃，相当于我们仪器分辨率的大约7%，适用于95%的数据。 然后，我们讨论了一种通过极坐标中值滤波来估计背景天空发射的新方法。这种方法抑制了来自遥远星系外晕的背景贡献，从而最大化了在相应天空减除图像中测量源的流量。 我们展示了针对中央波长为7615$\rm\AA$的数据，新生成的天空减除图像中的星系流量比现有OSIRIS可调滤光仪数据的天空减除图像中的星系流量高约37%。 显示英文摘要

摘要： We describe techniques concerning wavelength calibration and sky subtraction to maximise the scientific utility of data from tunable filter instruments. While we specifically address data from the Optical System for Imaging and low Resolution Integrated Spectroscopy instrument (OSIRIS) on the 10.4~m Gran Telescopio Canarias telescope, our discussion is generalisable to data from other tunable filter instruments. A key aspect of our methodology is a coordinate transformation to polar coordinates, which simplifies matters when the tunable filter data is circularly symmetric around the optical centre. First, we present a method for rectifying inaccuracies in the wavelength calibration using OH sky emission rings. Using this technique, we improve the absolute wavelength calibration from an accuracy of 5 Angstroms to 1 Angstrom, equivalent to ~7% of our instrumental resolution, for 95% of our data. Then, we discuss a new way to estimate the background sky emission by median filtering in polar coordinates. This method suppresses contributions to the sky background from the outer envelopes of distant galaxies, maximising the fluxes of sources measured in the corresponding sky-subtracted images. We demonstrate for data tuned to a central wavelength of 7615~$\rm\AA$ that galaxy fluxes in the new sky-subtracted image are ~37% higher, versus a sky-subtracted image from existing methods for OSIRIS tunable filter data.