论文标题
Gaia间隙和低质量恒星的物理学。 I.完全对流的边界
Gaia Gaps and the Physics of Low-Mass Stars. I. The Fully Convective Boundary
论文作者
论文摘要
Gaia M-Dwarf间隙是恒星的显着低密度，在$ m_g = 10.2 $接近$ m_g = 10.2 $中，在太阳200 pc的恒星的颜色数字图中。有人提出，由于非平衡$^{3} $融合，差距是恒星内部内部结构不稳定性的表现。为了检验这一假设，我们使用达特茅斯恒星进化模型，MARCS模型大气和简单的恒星种群合成来创建合成$ m_g $ - （$ g _ {\ rm bp} - g _ {\ rm rp}）$ color-magnitude图。我们确认提出的$^{3} $不稳定性负责M-Dwarf Gap的外观。我们的合成差距与观察到的差距在质量上相似，包括：其垂直范围为$ m_g $，其在颜色数字图中的斜率以及与红色相比，其相对突出的垂直范围及其相对突出。此外，模型在间隙上方的相应的恒星的相应过度密度再现。虽然在定性上相似，但合成间隙约为0.2个幅度，并且考虑到这种颜色偏移，比观察到的间隙更明亮。我们的结果表明，Gaia M矮间隙差距对M矮星的核心内的条件敏感，这使该间隙成为测试M矮星的物理学的强大工具，并有可能使用M DWARFS了解本地恒星形成历史。
The Gaia M-dwarf gap is a significant under-density of stars observed near $M_G = 10.2$ in a color-magnitude diagram for stars within 200 pc of the Sun. It has been proposed that the gap is the manifestation of structural instabilities within stellar interiors due to non-equilibrium $^{3}$He fusion prior to some stars becoming fully convective. To test this hypothesis, we use Dartmouth stellar evolution models, MARCS model atmospheres, and simple stellar population synthesis to create synthetic $M_G$-($G_{\rm BP} - G_{\rm RP})$ color-magnitude diagrams. We confirm that the proposed $^{3}$He instability is responsible for the appearance of the M-dwarf gap. Our synthetic gap shows qualitatively similar features to the observed gap including: its vertical extent in $M_G$, its slope in the color-magnitude diagram, and its relative prominence at bluer colors as compared to redder colors. Furthermore, corresponding over-densities of stars above the gap are reproduced by the models. While qualitatively similar, the synthetic gap is approximately 0.2 magnitudes bluer and, accounting for this color offset, 0.16 magnitudes brighter than the observed gap. Our results reveal that the Gaia M dwarf gap is sensitive to conditions within cores of M dwarf stars, making the gap a powerful tool for testing the physics of M dwarf stars and potentially using M dwarfs to understand the local star formation history.
