论文标题

Sami Galaxy调查:星系凸起和磁盘分解的恒星运动学

The SAMI Galaxy Survey: Decomposed Stellar Kinematics of Galaxy Bulges and Disks

论文作者

Oh, Sree, Colless, Matthew, Barsanti, Stefania, Casura, Sarah, Cortese, Luca, van de Sande, Jesse, Owers, Matt S., Scott, Nicholas, D'Eugenio, Francesco, Bland-Hawthorn, Joss, Brough, Sarah, Bryant, Julia J., Croom, Scott M., Foster, Caroline, Groves, Brent, Lawrence, Jon S., Richards, Samuel N., Sweet, Sarah M.

论文摘要

我们研究了826个星系中的隆起和磁盘成分的恒星运动学,并从Sydney-AAAO多对象整合体光谱(SAMI)星系调查中具有广泛的形态。使用惩罚的像素拟合(PPXF)方法同时估算了带有光图定义的权重的两个组件的加权(PPXF)方法,同时估算了凸起和磁盘成分的空间分辨旋转速度(V)和速度分散($σ$)。我们引入了一个新的PPXF子例程,用于处理解决方案中的退化。我们表明,可以使用凸起和磁盘组件的运动学和权重重建每个星系中的V和$σ$分布。两个不同组成部分的组合提供了对广泛形态类型的星系的主要运动学特征的一致描述。我们提出了Tully-Fisher和Faber-Jackson的关系,表明所有星系类型的两个组件的Galaxy Stellar质量尺度均具有V和$σ$。即使对于磁盘组件,我们也会发现紧密的Faber-Jackson关系。我们表明,凸起和磁盘成分在运动学上是不同的:(1)两个组件显示出与相似斜率但截距不同的缩放关系; (2)旋转参数$λ_r$表示凸起是压力为主导的系统,并且旋转支持磁盘; (3)凸起和磁盘成分分别具有内在椭圆度的低和高值。我们的发现表明,这两个组成部分的相对贡献至少解释了一阶星系的复杂运动学行为。

We investigate the stellar kinematics of the bulge and disk components in 826 galaxies with a wide range of morphology from the Sydney-AAO Multi-object Integral-field spectroscopy (SAMI) Galaxy Survey. The spatially-resolved rotation velocity (V) and velocity dispersion ($σ$) of bulge and disk components have been simultaneously estimated using the penalized pixel fitting (pPXF) method with photometrically defined weights for the two components. We introduce a new subroutine of pPXF for dealing with degeneracy in the solutions. We show that the V and $σ$ distributions in each galaxy can be reconstructed using the kinematics and weights of the bulge and disk components. The combination of two distinct components provides a consistent description of the major kinematic features of galaxies over a wide range of morphological types. We present Tully-Fisher and Faber-Jackson relations showing that the galaxy stellar mass scales with both V and $σ$ for both components of all galaxy types. We find a tight Faber-Jackson relation even for the disk component. We show that the bulge and disk components are kinematically distinct: (1) the two components show scaling relations with similar slopes, but different intercepts; (2) the spin parameter $λ_R$ indicates bulges are pressure-dominated systems and disks are supported by rotation; (3) the bulge and disk components have, respectively, low and high values in intrinsic ellipticity. Our findings suggest that the relative contributions of the two components explain, at least to first order, the complex kinematic behaviour of galaxies.

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