Propiedades de discos y esferoides en galaxias simuladas

CRISTIANI, V. A; ABADI, M. G.

Boletín de la Asociación Argentina de Astronomía

Asociación Argentina de Astronomía

Año: 2024 vol. 64 p. 250 - 252

1669-9521

Galaxies are complex stellar systems formed by several overlapping stellar components (bulge, disk, bar, etc.) whose formation and evolution process is inherently related to the individual processes undergone by each of them. We study the properties of discs and spheroids by applying two dynamical decomposition methods to a sample of galaxies with stellar masses > 1010 M⊙ identified in the EAGLE and ILLUSTRISTNG cosmological numerical simulations. In agreement with observational results, we find that the stellar mass fraction in the spheroidal component fsph increases systematically with galaxy stellar mass M* from fractions of 50% for galaxies of M*∼1010 M⊙ to 90% for M*∼ 1012 M⊙, although with a fair amount of scatter. For galaxies with stellar masses similar to that of the Milky Way (M*∼1010.6 M⊙) and applying isolation criteria we find fsph∼0.2 at best which is only slightly higher than the lowest values estimated observationally for local galaxies fsph∼0.15. This would indicate that the cosmological volume simulations are capable of reproducing a population of disk galaxies comparable to those observed. In addition, the scaling relations between mass, specific angular momentum and characteristic velocity of disks and spheroids are shown and how they compare with those of full galaxies and those obtained observationally, such as the Tully-Fisher and Faber-Jackson relations.