Covariance-regularized Reconstruction of Data Cubes in Integral Field Spectroscopy and Application to MaNGA Data
Covariance-regularized Reconstruction of Data Cubes in Integral Field Spectroscopy and Application to MaNGA Data
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DOI：
10.3847/1538-3881/ab5aeb
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发表时间：
2019-06
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通讯作者：
Donglai Liu;M. Blanton;D. Law
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作者：
Donglai Liu;M. Blanton;D. Law
积分场光谱学可以在空间和光谱上绘制天体。由于仪器和大气的影响，积分场仪器通常会产生不规则的和波长相关的天空图像采样。大多数后续分析程序需要定期的、与波长无关的采样（例如固定的矩形网格），因此至关重要的初始步骤是将数据重新采样到新的网格上。最好的可能的重采样将产生一个良好的采样图像，其分辨率等于仪器，望远镜和大气的固有空间分辨率，并且相邻像素之间没有统计相关性。本领域中从不规则样本集合产生规则样本集合的标准方法是谢泼德的方法，但是谢泼德的方法通常产生分辨率降低且像素之间具有大的统计相关性的图像。本文介绍一种新的方法，它在这两个方面都对谢泼德的方法作了改进。我们应用这种方法的数据从映射附近的Galerkin在阿帕奇点天文台的调查，斯隆数字巡天IV的一部分，展示了一个完整的半高宽接近的内在空间分辨率（和1016%优于谢泼德的方法）和像素之间的统计相关性低。这些结果几乎达到了理想的效果。该方法对其他积分场数据集和其他不规则采样的天文数据集（如抖动图像）具有更广泛的应用。
Integral field spectroscopy can map astronomical objects spatially and spectroscopically. Due to instrumental and atmospheric effects, it is common for integral field instruments to yield a sampling of the sky image that is both irregular and wavelength dependent. Most subsequent analysis procedures require a regular, wavelength-independent sampling (for example a fixed rectangular grid), and thus an initial step of fundamental importance is to resample the data onto a new grid. The best possible resampling would produce a well-sampled image, with a resolution equal to that imposed by the intrinsic spatial resolution of the instrument, telescope, and atmosphere, and with no statistical correlations between neighboring pixels. A standard method in the field to produce a regular set of samples from an irregular set of samples is Shepard’s method, but Shepard’s method typically yields images with a degraded resolution and large statistical correlations between pixels. Here we introduce a new method, which improves on Shepard’s method in both these respects. We apply this method to data from the Mapping Nearby Galaxies at Apache Point Observatory survey, part of Sloan Digital Sky Survey IV, demonstrating a full width at half maximum close to that of the intrinsic spatial resolution (and ∼16% better than Shepard’s method) and low statistical correlations between pixels. These results nearly achieve the ideal resampling. This method can have broader applications to other integral field data sets and to other astronomical data sets (such as dithered images) with irregular sampling.