Are ring galaxies the ancestors of giant low surface brightness galaxies?

TL;DR

This study uses simulations to propose that giant low surface brightness galaxies (GLSBs) may originate from collisional ring galaxies, providing insights into their formation within the cold dark matter framework.

Contribution

It demonstrates through simulations that ring galaxies can evolve into GLSBs, offering a new formation pathway consistent with observations and the CDM model.

Findings

Simulated galaxies resemble observed ring galaxies 100-200 Myr after collision.

Extended, flat discs (~100 kpc) form 0.5-1 Gyr post-collision, matching GLSB properties.

Simulations align well with observed properties of specific GLSBs.

Abstract

We simulate the collisional formation of a ring galaxy and we integrate its evolution up to 1.5 Gyr after the interaction. About 100-200 Myr after the collision, the simulated galaxy is very similar to observed ring galaxies (e.g. Cartwheel). After this stage, the ring keeps expanding and fades. Approximately 0.5-1 Gyr after the interaction, the disc becomes very large (~100 kpc) and flat. Such extended discs have been observed only in giant low surface brightness galaxies (GLSBs). We compare various properties of our simulated galaxies (surface brightness profile, morphology, HI spectrum and rotation curve) with the observations of four well-known GLSBs (UGC6614, Malin 1, Malin 2 and NGC7589). The simulations match quite well the observations, suggesting that ring galaxies could be the progenitors of GLSBs. This result is crucial for the cold dark matter (CDM) model, as it was very difficult, so far, to explain the formation of GLSBs within the CDM scenario.