Kinematic decomposition of IllustrisTNG disk galaxies: morphology and relation with morphological structures

摘要: We recently developed an automated method, auto-GMM to decompose simulated galaxies. It extracts kinematic structures in accurate, efficient, and unsupervised way. use study the stellar of disk galaxies from TNG100 run IllustrisTNG. identify four five that are commonly present among diverse galaxy population. Structures having strong moderate rotation defined as cold warm disks, respectively. Spheroidal dominated by random motions classified bulges or halos, depending on how tightly bound they are. Disky have but compact morphology. Across all disky accounting for mass within 3 half-mass radii, spheroidal structures, obtained summing up stars contribute ~45% total mass, while constitute 55%. This also provides important insights about relationship between kinematically morphologically derived galactic structures. Comparing morphology with traditional bulge+disk decomposition, we conclude: (1) decomposed composite comprised a slowly rotating bulge, inner halo, bulge; (2) bulges, akin what called pseudo observations, disk-like components similar disks; (3) halos almost 30% surface density outer part morphological disks when viewed face-on; (4) both often truncated central regions.