The luminosities of cool supergiants in the Magellanic Clouds, and the Humphreys-Davidson limit revisited
The luminosities of cool supergiants in the Magellanic Clouds, and the Humphreys-Davidson limit revisited
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麦哲伦云中冷超巨星的光度和汉弗莱斯-戴维森极限的重新审视
DOI：
10.1093/mnras/sty1302
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发表时间：
2018
影响因子：
4.8
通讯作者：
Davies B
中科院分区：
文献类型：
--
作者：
Davies B
冷超巨星（SG）的经验光度上限Lmax，通常被称为汉弗莱-戴维森极限，被认为编码了大质量恒星一般质量损失行为的信息。此外，它还描绘出了单颗恒星将在剥离富氢外壳后结束生命的边界，这反过来又是单颗星星通道中II型到Ibc型超新星相对速率的关键因素。本文通过对大、小麦哲伦云（LMC/SMC）中冷星系团光度分布的研究，重新讨论了Lmax的问题。我们收集了每个星系中高度完整且logL/L⊙= 5.0以上的冷SG样本，并使用现代多波长测量数据确定了它们从光学到中红外的光谱能量分布。我们表明，在这两种情况下，Lmax似乎是低于以前引用的，是在该地区的logL/L = 5.5。没有证据表明Lmax在SMC中比在LMC中更高，如果金属性相关风是剥离恒星包层的主导因素，那么这将是预期的。我们还表明，Lmax与单个富氮沃尔夫-拉叶星的最低光度一致，表明临界质量以上的恒星演化序列发生了变化。从人口合成分析，我们表明，日内瓦进化模型大大高估了在SMC的冷SG的数量。我们还认为，在较低的金属丰度环境中，较早的平均光谱类型的冷SG的趋势代表了一个真正的转变到更热的温度。最后，我们使用我们的新的热光度测量提供更新的热校正冷SG。
The empirical upper luminosity boundaryLmaxof cool supergiants (SGs), often referred to as the Humphreys-Davidson limit, is thought to encode information on the general mass-loss behaviour of massive stars. Further, it delineates the boundary at which single stars will end their lives stripped of their hydrogen-rich envelope, which in turn is a key factor in the relative rates of Type-II to Type-Ibc supernovae from single star channels. In this paper we have revisited the issue ofLmaxby studying the luminosity distributions of cool SGs in the Large and Small Magellanic Clouds (LMC/SMC). We assemble samples of cool SGs in each galaxy which are highly complete above logL/L⊙= 5.0, and determine their spectral energy distributions from the optical to the mid-infrared using modern multiwavelength survey data. We show that in both casesLmaxappears to be lower than previously quoted, and is in the region of logL/L⊙= 5.5. There is no evidence forLmaxbeing higher in the SMC than in the LMC, as would be expected if metallicity-dependent winds were the dominant factor in the stripping of stellar envelopes. We also show thatLmaxaligns with the lowest luminosity of single nitrogen-rich Wolf-Rayet stars, indicating of a change in evolutionary sequence for stars above a critical mass. From population synthesis analysis we show that the Geneva evolutionary models greatly overpredict the numbers of cool SGs in the SMC. We also argue that the trend of earlier average spectral types of cool SGs in lower metallicity environments represents a genuine shift to hotter temperatures. Finally, we use our new bolometric luminosity measurements to provide updated bolometric corrections for cool SGs.
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影响因子：
4.8
作者：
S. Goldman;J. V. Loon;A. Zijlstra;J. Green;P. Wood;A. Nanni;H. Imai;P. Whitelock;M. Matsuura-M.-Ma
通讯作者：
S. Goldman;J. V. Loon;A. Zijlstra;J. Green;P. Wood;A. Nanni;H. Imai;P. Whitelock;M. Matsuura-M.-Ma
对麦哲伦云中冷超巨星的新调查
DOI：
--
发表时间：
2015
期刊：
影响因子：
--
作者：
C. Gonz'alez;R. Dorda;I. Negueruela;A. M. I. O. Astronomy;U. Cambridge;Dfists;U. Alicante
通讯作者：
U. Alicante
影响因子：
6.5
作者：
M. R. Mokiem;A. D. Koter;J. Vink;J. Puls;C. Evans;S. Smartt;P. Crowther;A. Herrero;A. Herrero;N. Langer;D. Lennon;F. Najarro;M. R. Villamariz
通讯作者：
M. R. Mokiem;A. D. Koter;J. Vink;J. Puls;C. Evans;S. Smartt;P. Crowther;A. Herrero;A. Herrero;N. Langer;D. Lennon;F. Najarro;M. R. Villamariz
发光蓝色变量 R71 的 S Doradus 爆发期间的光谱和光度振荡包络变化
影响因子：
6.5
作者：
A. Mehner;D. Baade;J. Groh;T. Rivinius;F. Hambsch;E. Bartlett;D. Asmus;C. Agliozzo;T. Szeifert;O. Stahl
通讯作者：
O. Stahl
DOI：
10.1086/157388
发表时间：
1979
期刊：
The Astrophysical Journal
影响因子：
--
作者：
R. Stothers;C. Chin
通讯作者：
C. Chin