论文标题
附近金属贫困矮星系中的OBE星星的人口普查揭示了很大的极端旋转器
A census of OBe stars in nearby metal-poor dwarf galaxies reveals a high fraction of extreme rotators
论文作者
论文摘要
早期的宇宙以及附近的许多矮星系中都缺乏沉重的元素。在这种环境中，巨大恒星的演变被认为受旋转影响。它们之间的极端旋转器倾向于形成决策磁盘，并表现为OBE星星。我们使用U B，Gaia，Spitzer和Hubble空间望远镜光度法的组合来识别附近的五个矮人星系中的巨大OBE恒星的完整种群（数量一百千万）。这使我们能够得出OBE恒星（F_OBE）的主要序列星的星系范围范围，以及它如何取决于绝对幅度，质量和金属度（Z）。我们在大型麦哲伦云（0.5 Z_SUN）中发现F_OBE = 0.22，在小麦哲伦云（0.2 Z_SUN）中增加到F_OBE = 0.31。在霍姆伯格I，霍尔姆伯格II和塞克斯坦A的迄今未探索的金属性态度下，我们也分别获得0.27、0.27、0.27和0.27的高obe星级。这些高OBE恒星的分数以及在恒星质量范围内的强大贡献，它主导了超新星的产生，在OBE恒星的形成通道以及长期持续性伽马射线爆发和超浮肿超新星的偏好上为金属poor星系中出现。
The Early Universe, together with many nearby dwarf galaxies, is deficient in heavy elements. The evolution of massive stars in such environments is thought to be affected by rotation. Extreme rotators amongst them tend to form decretion disks and manifest themselves as OBe stars. We use a combination of U B, GAIA, Spitzer, and Hubble Space Telescope photometry to identify the complete populations of massive OBe stars - one hundred to thousands in number - in five nearby dwarf galaxies. This allows us to derive the galaxy-wide fractions of main sequence stars that are OBe stars (f_OBe), and how it depends on absolute magnitude, mass, and metallicity (Z). We find f_OBe = 0.22 in the Large Magellanic Cloud (0.5 Z_Sun), increasing to f_OBe = 0.31 in the Small Magellanic Cloud (0.2 Z_Sun). In the so far unexplored metallicity regime below 0.2 Z_Sun, in Holmberg I, Holmberg II, and Sextans A, we also obtain high OBe star fractions of 0.27, 0.27, and 0.27, respectively. These high OBe star fractions, and the strong contribution in the stellar mass range which dominates the production of supernovae, shed new light on the formation channel of OBe stars, as well as on the preference of long-duration gamma-ray bursts and superluminous supernovae to occur in metal-poor galaxies.
