Type II Plateau supernovae as metallicity probes of the Universe
Type II Plateau supernovae as metallicity probes of the Universe
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DOI：
10.1093/mnras/stu417
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发表时间：
2014-03
影响因子：
4.8
通讯作者：
L. Dessart;C. Gutiérrez;M. Hamuy;D. Hillier;T. Lanz;J. Anderson;G. Folatelli;W. Freedman;
中科院分区：
文献类型：
--
作者：
L. Dessart;C. Gutiérrez;M. Hamuy;D. Hillier;T. Lanz;J. Anderson;G. Folatelli;W. Freedman;
我们探索了一种基于ii -高原（II-P）超新星（SNe）定量光谱的金属丰度测定方法。为了保持一致性，我们首先演化出一组15Msun的主序星，它们的金属丰度分别是太阳的0.1、0.4、1和2倍。在地核坍塌开始时，我们触发活塞驱动的爆炸并模拟由此产生的喷出物和辐射。我们对不同金属丰度的红超巨星爆炸的理论模型表明，SNe II-P的合成光谱在复合阶段具有对金属丰度变化敏感的光学特征。这种灵敏度可以量化，金属丰度可以从金属线吸收的强度推断出来。此外，这些特征不仅限于O，还包括Na， Ca, Sc， Ti或Fe。通过与卡内基SN项目和之前的SN后续项目的snii - p样品进行比较，我们发现大多数snii - p事件的金属丰度在0.4 - 2倍太阳之间，而SMC金属丰度的snii - p事件明显稀缺。这很可能反映了本地宇宙中低金属丰度恒星形成区域的缺乏。snii - p具有很高的平台光度，使它们在很远的距离上都能被光谱观测到。因为它们表现出不同金属物种的特征，在未来，它们可能提供一种方法来限制宇宙中成分（例如，O/Fe比）的演化，使其红移达到1或更大。
We explore a method for metallicity determinations based on quantitative spectroscopy of type II-Plateau (II-P) supernovae (SNe). For consistency, we first evolve a set of 15Msun main sequence stars at 0.1, 0.4, 1, and 2 x the solar metallicity. At the onset of core collapse, we trigger a piston-driven explosion and model the resulting ejecta and radiation. Our theoretical models of such red-supergiant-star explosions at different metallicity show that synthetic spectra of SNe II-P possess optical signatures during the recombination phase that are sensitive to metallicity variations. This sensitivity can be quantified and the metallicity inferred from the strength of metal-line absorptions. Furthermore, these signatures are not limited to O, but also include Na, Ca, Sc, Ti, or Fe. When compared to a sample of SNe II-P from the Carnegie SN Project and previous SN followup programs, we find that most events lie at a metallicity between 0.4 and 2 x solar, with a marked scarcity of SN II-P events at SMC metallicity. This most likely reflects the paucity of low metallicity star forming regions in the local Universe. SNe II-P have high plateau luminosities that make them observable spectroscopically at large distances. Because they exhibit signatures of diverse metal species, in the future they may offer a means to constrain the evolution of the composition (e.g., the O/Fe ratio) in the Universe out to a redshift of one and beyond.