The evolution of Red Supergiant mass-loss rates
The evolution of Red Supergiant mass-loss rates
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DOI：
10.1093/mnras/stx3174
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发表时间：
2017-12
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影响因子：
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通讯作者：
Emma R. Beasor;B. Davies
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文献类型：
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作者：
Emma R. Beasor;B. Davies
初始质量为b> 8M $_\odot$的大质量恒星的命运在很大程度上取决于它们生命最后阶段的质量损失率（\mdot）。红超巨星（RSGs）是II-P型核心坍缩超新星（SN）的直接祖先，但在这一阶段，任何质量损失的规模和影响都是不确定的。在这里，我们使用近红外和中红外光度法和辐射传输代码DUSTY来确定两个星系团（NGC 7419和$\chi$ Per）中rsg的光度和\mdot值，其中rsg都具有相似的初始质量（$M_{\rm initial}$$\sim$ 16M $_\odot$），使我们能够研究\mdot如何随时间沿着进化序列变化。我们发现亮度和\mdot之间有一个清晰而紧密的联系，这表明在野外恒星研究中看到的散射是由相似亮度的恒星具有不同的初始质量造成的。根据我们的结果，我们估计一颗16M的$_\odot$恒星在RSG阶段会损失多少质量，找到一颗这样质量的恒星总共会损失0.61 $^{+0.92}_{-0.31}$ M $_\odot$。这比目前在进化模型中使用的\mdot处方的预期要少得多。
The fate of massive stars with initial masses >8M$_\odot$ depends largely on the mass-loss rate (\mdot ) in the end stages of their lives. Red supergiants (RSGs) are the direct progenitors to Type II-P core collapse supernovae (SN), but there is uncertainty regarding the scale and impact of any mass-loss during this phase. Here we used near and mid-IR photometry and the radiative transfer code DUSTY to determine luminosity and \mdot\ values for the RSGs in two Galactic clusters (NGC 7419 and $\chi$ Per) where the RSGs are all of similar initial mass ($M_{\rm initial}$$\sim$16M$_\odot$), allowing us to study how \mdot\ changes with time along an evolutionary sequence. We find a clear, tight correlation between luminosity and \mdot\ suggesting the scatter seen in studies of field stars is caused by stars of similar luminosity being of different initial masses. From our results we estimate how much mass a 16M$_\odot$ star would lose during the RSG phase, finding a star of this mass would lose a total of 0.61$^{+0.92}_{-0.31}$M$_\odot$. This is much less than expected for \mdot\ prescriptions currently used in evolutionary models.