论文标题
低阶$Δν$ - $ {\ barρ} $中等旋转$δ$Δ$ scuti星的关系及其对其特征的影响
Study of the low-order $Δν$-${\bar ρ}$ relation for moderately-rotating $δ$ Scuti stars and its impact on their characterisation
论文作者
论文摘要
由于其独立性，因此在低径向阶制度中的大分离被认为是$δ$ scuti恒星的平均密度的高度有价值。到目前为止，该$Δν$ - $ {\barρ} $关系的理论研究仅限于1D非旋转模型和2D伪进化模型。目前的工作旨在通过定量研究旋转对$δ$ Scuti星的一维星号模型的大网格的旋转影响来完成这种情况。这些包括对恒星进化的旋转影响以及与脉动的相互作用。这使我们能够计算出恒星变形，获得极性和赤道半径，并校正恒星平均密度。我们发现，用于旋转模型的新的$Δν$ - $ {\ barρ} $与以前的作品兼容。我们解释了线性拟合周围点的分散，这主要是由于恒星质量的分布而部分由进化阶段引起的。发现新的拟合度与以前的较低群众的理论研究接近（$ 1.3-1.81 \，\ Mathrm {m} _ {\ odot} $）。但是，相反的观察结果是：对于更高的质量（$ 1.81-3 \，\ mathrm {m} _ {\ odot} $），拟合与经验关系更兼容。我们应用了这些结果来表征Corot，HD174936和HD174966观察到的两个众所周知的$δ$ SCUTI星，并将物理参数与以前的作品进行了比较。在建模中包含旋转会导致倾向更大的质量，半径，亮度和较低的密度值。 $Δν$和GAIA的亮度之间的比较也使我们能够限制这两颗恒星的倾斜角度和旋转速度。目前的结果铺平了系统地约束$Δ$ scuti星的倾斜角度的方式
The large separation in the low radial order regime is considered as a highly valuable observable to derive mean densities of $δ$ Scuti stars, due to its independence with rotation. Up to now, theoretical studies of this $Δν$-${\bar ρ}$ relation have been limited to 1D non-rotating models, and 2D pseudo-evolutionary models. The present work aims at completing this scenario by investigating quantitatively the impact of rotation in this relation on a large grid of 1D asteroseismic models representative of $δ$ Scuti stars. These include rotation effects on both the stellar evolution and the interaction with pulsation. This allowed us to compute the stellar deformation, get the polar and equatorial radii, and correct the stellar mean densities. We found that the new $Δν$-${\bar ρ}$ relation for rotating models is compatible with previous works. We explained the dispersion of the points around the linear fits as caused mainly by the distribution of the stellar mass, and partially by the evolutionary stage. The new fit is found to be close to the previous theoretical studies for lower masses ($1.3-1.81\,\mathrm{M}_{\odot}$). However, the opposite holds for the observations: for the higher masses ($1.81-3\,\mathrm{M}_{\odot}$) the fit is more compatible with the empirical relation. We applied these results to characterise the two well-known $δ$ Scuti stars observed by CoRoT, HD174936 and HD174966, and compared the physical parameters with those of previous works. Inclusion of rotation in the modelling causes a tendency towards greater masses, radii, luminosities and lower density values. Comparison between $Δν$ and Gaia's luminosities also allowed us to constraint the inclination angles and rotational velocities of both stars. The present results pave the way to systematically constrain the angle of inclination of $δ$ Scuti stars
