恒星参数的系统不确定性对恒星星族积分谱的影响
The impact of systematic uncertainties in stellar parameters on integrated spectra of stellar populations
摘要：
在本文中，我们调查了迄今为止尚未探索的来源潜在的显着误差的恒星星族合成（SPS）模型，所造成的系统不确定性与三个基本的恒星大气参数：有效温度T_eff，表面重力g，和铁丰度[Fe/H]。所有SPS模型都依赖于T_eff、logg和[Fe/H]标度的校准，这些标度在恒星模型、等时线和合成光谱中是隐含的，并且被明确地用于经验光谱库。我们评估了等时线和光谱库（SPS模型的两个关键组成部分）之间的尺度不匹配的影响，并量化了对23个常用诊断线指数的影响。我们发现，典型的系统偏移100 K的T_eff，0.15 dex的[Fe/H]和/或0.25 dex的logg显着改变推断的绝对年龄的简单恒星星族（SSP），在某些情况下，相对年龄也发生变化。尺度太阳SSP的T_eff、logg和[Fe/H]尺度的偏移产生了与模型的偏差，这可以模拟改变丰度比对非尺度太阳化学成分的影响，也可以被错误地解释为更复杂人口的证据，特别是当使用多指数或全SED拟合方法时。我们强调，我们发现的行为可能会影响任何SPS模型，无论是使用完整的集成光谱或拟合函数来确定线强度。我们目前测量的偏移量在23个诊断线指数，并敦促谨慎过度解释线指数数据的恒星星族。
英文摘要：
In this paper we investigate a hitherto unexplored source of potentially significant error in stellar population synthesis (SPS) models, caused by systematic uncertainties associated with the three fundamental stellar atmospheric parameters; effective temperature T_eff, surface gravity g, and iron abundance [Fe/H]. All SPS models rely on calibrations of T_eff, logg and [Fe/H] scales, which are implicit in stellar models, isochrones and synthetic spectra, and are explicitly adopted for empirical spectral libraries. We assess the effect of a mismatch in scales between isochrones and spectral libraries (the two key components of SPS models) and quantify the effects on 23 commonly used diagnostic line indices. We find that typical systematic offsets of 100K in T_eff, 0.15 dex in [Fe/H] and/or 0.25 dex in logg significantly alter inferred absolute ages of simple stellar populations (SSPs) and that in some circumstances, relative ages also change. Offsets in T_eff, logg and [Fe/H] scales for a scaled-solar SSP produce deviations from the model which can mimic the effects of altering abundance ratios to non-scaled-solar chemical compositions, and could also be spuriously interpreted as evidence for a more complex population, especially when multiple-index or full-SED fitting methods are used. We stress that the behavior we find can potentially affect any SPS models, whether using full integrated spectra or fitting functions to determine line strengths. We present measured offsets in 23 diagnostic line indices and urge caution in the over-interpretation of line-index data for stellar populations.
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。
