arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1201.0910astro-ph.SR
收藏

模拟GK星的近紫外波段，论文II：NLTE模型

Modeling the near-UV band of GK stars, Paper II: NLTE models

C. Ian Short, Eamonn A. Campbell, Heather Pickup, Peter H. Hauschildt

备注：
Submitted to The Astrophysical Journal. Observed spectrophotometric library, and grids of NLTE and LTE) synthetic spectra for GK stars available at http://www.ap.smu.ca/~ishort/PHOENIX
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

我们提出了一个网格的大气模型和合成光谱能量分布（SED）的晚型矮星和巨星的太阳和1/3太阳的金属丰度与许多不透明度来源计算的自洽非本地热力学平衡（NLTE），并比较他们的LTE网格肖特和Hauschildt（2010）（论文I）。我们描述，第一次，如何NLTE治疗影响大气结构（T（τ）关系）和SED的热平衡作为一个精细采样的功能Teff，日志g，和[A/H]之间的太阳金属丰度和轻度金属贫红巨星。我们将计算的SED与论文I中描述的整个可见光谱带以及光谱的蓝色和红色区域中的观测分光光度法库进行比较。我们发现，对于这两个金属丰度的巨人，NLTE模型产生最佳拟合Teff值是~30至90 K比LTE模型提供的低，同时提供更大的一致性之间的\log g值，并为大角星，Teff值，分别拟合到蓝色和红色光谱区域。有边际的证据表明，NLTE模型给出了更一致的最佳拟合Teff值之间的红色和蓝色波段的早期光谱类的太阳金属量GK巨人比他们做的后期类，但没有模型适合的蓝色波段光谱以及任何类。对于我们能够研究的两个矮光谱类，NLTE对导出参数的影响不太显著。

英文摘要：

We present a grid of atmospheric models and synthetic spectral energy distributions (SEDs) for late-type dwarfs and giants of solar and 1/3 solar metallicity with many opacity sources computed in self-consistent Non-Local Thermodynamic Equilibrium (NLTE), and compare them to the LTE grid of Short & Hauschildt (2010) (Paper I). We describe, for the first time, how the NLTE treatment affects the thermal equilibrium of the atmospheric structure (T(tau) relation) and the SED as a finely sampled function of Teff, log g, and [A/H] among solar metallicity and mildly metal poor red giants. We compare the computed SEDs to the library of observed spectrophotometry described in Paper I across the entire visible band, and in the blue and red regions of the spectrum separately. We find that for the giants of both metallicities, the NLTE models yield best fit Teff values that are ~30 to 90 K lower than those provided by LTE models, while providing greater consistency between \log g values, and, for Arcturus, Teff values, fitted separately to the blue and red spectral regions. There is marginal evidence that NLTE models give more consistent best fit Teff values between the red and blue bands for earlier spectral classes among the solar metallicity GK giants than they do for the later classes, but no model fits the blue band spectrum well for any class. For the two dwarf spectral classes that we are able to study, the effect of NLTE on derived parameters is less significant.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑