论文标题
Z = 7.54的最遥远的类星体的BLR气体中，人口III配对超稳定性超新星弹出的潜在特征
Potential signature of Population III pair-instability supernova ejecta in the BLR gas of the most distant quasar at z = 7.54
论文作者
论文摘要
数十年来，寻找人口III（流行III）的明星已经着迷并躲避了天体物理学家。捕获其存在证据的一个有前途的地方必须是高红移对象。签名应记录在其特征化学丰度中。我们从Ukidss大面积调查（ULAS）J1342+0928 $ Z = 7.54 $中的紫外线MG II和Fe II排放线的强度从紫外线MG II和Fe II发射线的强度中推断出Fe和Mg的丰度，该新型Flux-to-to-quas $ quas sim $ qu qus sim 1 $ qu qus nim nim $ qu qus。我们发现，相对于太阳能丰度，该类星体的BLR非常丰富，同时相对于太阳能丰度，以及非常低的mg/fe丰度比：$ [\ MATHRM {fe/h}] =+1.36 \ pm0.19 $ and $ [\ pm0.19 $ and $ [\ mathrm {mg/fe/fe/fe {mg/fe}]我们得出的结论是，这种异常丰度的特征无法通过仅考虑规范超新星的贡献的化学演化标准观点来解释。尽管流行III IMF的高质量端仍存在不确定性，但在这里我们提出，Ulas J1342+0928中的铁量大量是由配对不稳定的超新星（PISN）提供的，这是由于大型流行音乐巨星在150-300 $ m_ $ m_ \ osot of 150-300 $ m_ $ m_ \ odot造成的巨大流行星端爆炸引起的。基于初始PISN富集的化学进化模型很好地解释了[fe/mg] - $ z $的趋势，从$ z <3 $到$ z = 7.54 $。我们预测，所有金属性的恒星都隐藏在银河系中，并且将通过正在进行的新一代光度测量有效地发现它们。
The search for Population III (Pop III) stars has fascinated and eluded astrophysicists for decades. One promising place for capturing evidence of their presence must be high-redshift objects; signatures should be recorded in their characteristic chemical abundances. We deduce the Fe and Mg abundances of the broad-line region (BLR) from the intensities of ultraviolet Mg II and Fe II emission lines in the near-infrared spectrum of UKIDSS Large Area Survey (ULAS) J1342+0928 at $z = 7.54$, by advancing our novel flux-to-abundance conversion method developed for $z\sim 1$ quasars. We find that the BLR of this quasar is extremely enriched, by a factor of 20 relative to the solar Fe abundance, together with a very low Mg/Fe abundance ratio: $[\mathrm{Fe/H}]=+1.36\pm0.19$ and $[\mathrm{Mg/Fe}]=-1.11\pm0.12$, only 700 million years after the Big Bang. We conclude that such an unusual abundance feature cannot be explained by the standard view of chemical evolution that considers only the contributions from canonical supernovae. While there remains uncertainty in the high-mass end of the Pop III IMF, here we propose that the larger amount of iron in ULAS J1342+0928 was supplied by a pair-instability supernova (PISN) caused by the explosion of a massive Pop III star in the high-mass end of the possible range of 150-300 $M_\odot$. Chemical-evolution models based on initial PISN enrichment well explain the trend in [Fe/Mg]-$z$ all the way from $z < 3$ to $z = 7.54$. We predict that stars with very low [Mg/Fe] at all metallicities are hidden in the Galaxy, and they will be efficiently discovered by ongoing new-generation photometric surveys.
