论文标题

白矮人光谱分析的计算工具

Computational Tools for the Spectroscopic Analysis of White Dwarfs

论文作者

Chandra, Vedant, Hwang, Hsiang-Chih, Zakamska, Nadia L., Budavári, Tamás

论文摘要

白矮人的光谱特征是在其恒星光球的薄上层中形成的。这些特征带有有关白矮人表面温度,表面重力和化学成分(以下称“标签”)的信息。确定这些标签的现有方法依赖于并非总是公开可用的复杂AB-Initio理论模型。在这里,我们提出了两种技术,以确定白矮谱的大气标签:一种生成拟合管道,该管道使用人工神经网络插值理论光谱,以及使用吸收线特征衍生的参数的随机森林回归模型。我们使用斯隆数字天空调查(SDSS)的大量白色矮人目录来测试和比较我们的方法,与以前的研究相比,实现了相同的准确性和可忽略的偏差。我们将技术包装到开源python模块“ WDTools”中,该模块提供了一种计算廉价的方式,可以从任何设施中观察到的白色矮人光谱中确定出色的标签。随着更多的理论模型公开可用,我们将积极开发和更新我们的工具。我们以目前的形式讨论我们的工具的应用,以识别有趣的异常白矮人系统,包括具有磁场,富含氦气的气氛和双层二进制二进制二元的系统。

The spectroscopic features of white dwarfs are formed in the thin upper layer of their stellar photosphere. These features carry information about the white dwarf's surface temperature, surface gravity, and chemical composition (hereafter 'labels'). Existing methods to determine these labels rely on complex ab-initio theoretical models which are not always publicly available. Here we present two techniques to determine atmospheric labels from white dwarf spectra: a generative fitting pipeline that interpolates theoretical spectra with artificial neural networks, and a random forest regression model using parameters derived from absorption line features. We test and compare our methods using a large catalog of white dwarfs from the Sloan Digital Sky Survey (SDSS), achieving the same accuracy and negligible bias compared to previous studies. We package our techniques into an open-source Python module 'wdtools' that provides a computationally inexpensive way to determine stellar labels from white dwarf spectra observed from any facility. We will actively develop and update our tool as more theoretical models become publicly available. We discuss applications of our tool in its present form to identify interesting outlier white dwarf systems including those with magnetic fields, helium-rich atmospheres, and double-degenerate binaries.

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