标题： M31和M33的超新星前身星质量分布：上限质量限制的进一步证据 显示英文标题

标题： The Supernova Progenitor Mass Distributions of M31 and M33: Further Evidence for an Upper Mass Limit

摘要： 利用哈勃太空望远镜（HST）测光来测量恒星形成历史，我们对M31和M33中超新星遗迹（SNRs）周围的恒星群体进行了年龄测定。然后，我们将恒星演化模型应用于这些年龄，以推断相应超新星前身星的质量。在这项工作中，我们分析了33个M33 SNR前身星和29个M31 SNR前身星。随后，我们将这些测量结果与之前发表的53个M31 SNR前身星测量结果相结合，使我们的前身星质量估算总数达到115个。为了量化质量分布，我们拟合了形式为$dN/dM \propto M^{-\alpha}$的幂律。我们的新样本——更大的M31前身星样本遵循一个具有$\alpha = 4.4\pm 0.4$的分布，而M33样本则遵循一个具有$\alpha = 3.8^{+0.4}_{-0.5}$的分布。因此，这两个样本在不确定性范围内是一致的，并且两个星系的完整样本给出了$\alpha = 4.2\pm 0.3$。与萨尔皮特初始质量函数（IMF）相比，无论是单独还是整体分布都显示出大质量恒星的匮乏，这正是我们预期的，如果所有大质量恒星都会爆炸成为留下可观察到的SNR的超新星的话。如果我们反过来固定$\alpha = 2.35$并将最大质量作为自由参数，我们发现$M_{max} \sim 35-45M_{sun}$，表明可能存在一个超新星产生的最大质量截断值。我们的结果表明，要么超新星遗迹调查对在最年轻（<10百万年）区域找到目标存在偏见，要么最高质量的恒星不会产生超新星。 显示英文摘要

摘要： Using Hubble Space Telescope (HST) photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitors in this work. We then combine these measurements with 53 previously published M31 SNR progenitor measurements to bring our total number of progenitor mass estimates to 115. To quantify the mass distributions, we fit power laws of the form $dN/dM \propto M^{-\alpha}$. Our new, larger sample of M31 progenitors follows a distribution with $\alpha = 4.4\pm 0.4$, and the M33 sample follows a distribution with $\alpha = 3.8^{+0.4}_{-0.5}$. Thus both samples are consistent within the uncertainties, and the full sample across both galaxies gives $\alpha = 4.2\pm 0.3$. Both the individual and full distributions display a paucity of massive stars when compared to a Salpeter initial mass function (IMF), which we would expect to observe if all massive stars exploded as SN that leave behind observable SNR. If we instead fix $\alpha = 2.35$ and treat the maximum mass as a free parameter, we find $M_{max} \sim 35-45M_{sun}$, indicative of a potential maximum cutoff mass for SN production. Our results suggest that either SNR surveys are biased against finding objects in the youngest (<10 Myr old) regions, or the highest mass stars do not produce SNe.