论文标题
关于使用硫作为星系丰度的示踪剂
On the use of Sulphur as a tracer for abundances in galaxies
论文作者
论文摘要
我们提出了一种在星系中使用硫作为全局金属示踪剂的方法，仅使用红色到新的红外光谱区域进行完整的丰度分析。我们已将其应用于高质量数据的汇编中，分为两个样本：螺旋和不规则星系中的HII区域（DHR），以及由强烈的Starburst（Hiigal）主导的矮星系。硫的丰度已通过直接方法得出，在一个由两个区域组成的电离结构的假设下：一个中间体，其中S {++}起源于S {++}，而在其中形成了S {+}的低电离。电离校正因子（ICF）已从AR {2+}/ar {3+}比率计算出来，并显示与辐射场的硬度相关。只有大约10％的对象显示S {3+}对总丰度大于30％的贡献。硫丰度与电离温度之间存在良好的相关性，而较低的恒星电离对象则存在电离温度。电离参数和总S/H丰度之间没有发现相关性。大多数Hiigal对象显示出低于太阳值的S/O比，并且随着硫丰度的增加而增加了S/O比的趋势，而DHR对象显示S/O比的S/O比大于太阳能，并且具有较低金属金属比率的S/O比率较低。最后，我们通过s {23}参数对硫丰度进行了校准，该参数保持单个价值超出太阳值以外的硫丰度。 S {23}独立于电离参数，仅弱依赖于电离温度。
We present a methodology for the use of sulphur as global metallicity tracer in galaxies, allowing performing a complete abundance analysis using only the red-to-near infrared spectral region. We have applied it to a compilation of high-quality data split into two samples: HII regions (DHR) in spiral and irregular galaxies, and dwarf galaxies dominated by a strong starburst (HIIGal). Sulphur abundances have been derived by direct methods under the assumption of an ionisation structure composed of two zones: an intermediate one where S{++} is originated and a low ionisation one where S{+} is formed. Ionisation correction factors (ICF) have been calculated from the Ar{2+}/Ar{3+} ratio and are shown to correlate with the hardness of the radiation field. Only about 10% of the objects show S{3+} contributions to the total abundance larger than 30%. A good correlation exists between sulphur abundance and ionising temperature with low metallicity objects being ionised by hotter stars. No correlation is found between ionisation parameter and total S/H abundance. Most of the HIIGal objects show S/O ratios below the solar value and a trend for increasing S/O ratios with increasing sulphur abundances while DHR objects show S/O ratios larger than solar and a tendency for lower S/O ratios for higher metallicities. Finally, we present a calibration of the sulphur abundance through the S{23} parameter that remains single valued up to sulphur abundances well beyond the solar value. S{23} is independent of the ionisation parameter and only weakly dependent on ionising temperature.
