• DOI:10.3847/1538-4357/aba434
• Corpus ID: 220646855

Dark Matter Deficient Galaxies Produced via High-velocity Galaxy Collisions in High-resolution Numerical Simulations

@article{Shin2020DarkMD,
  title={Dark Matter Deficient Galaxies Produced via High-velocity Galaxy Collisions in High-resolution Numerical Simulations},
  author={Eunjee Shin and Mi Ok Jung and Go Eun Kwon and Ji-hoon Kim and Joohyun Lee and Yongseok Jo and Boon Kiat Oh},
  journal={arXiv: Astrophysics of Galaxies},
  year={2020}
}

• Eunjee Shin, M. Jung, +4 authors Boon Kiat Oh
• Published 20 July 2020
• Physics
• arXiv: Astrophysics of Galaxies

The recent discovery of diffuse dwarf galaxies that are deficient in dark matter appears to challenge the current paradigm of structure formation in our Universe. We describe the numerical experiments to determine if the so-called dark matter deficient galaxies (DMDGs) could be produced when two gas-rich, dwarf-sized galaxies collide with a high relative velocity of $\sim 300\,{\rm kms^{-1}}$. Using idealized high-resolution simulations with both mesh-based and particle-based gravito-hydrodynamics codes, we find that DMDGs can form as high-velocity galaxy collisions separate dark matter from the warm disk gas which subsequently is compressed by shock and tidal interaction to form stars. Then using a large simulated universe IllustrisTNG, we discover a number of high-velocity galaxy collision events in which DMDGs are expected to form. However, we did not find evidence that these types of collisions actually produced DMDGs in the TNG100-1 run. We argue that the resolution of the numerical experiment is critical to realize the "collision-induced" DMDG formation scenario. Our results demonstrate one of many routes in which galaxies could form with unconventional dark matter fractions.