MeerKAT imaging of nearby galaxies

Star formation is one of the dominant internal processes that drive galaxy evolution. We investigate the environmental effects on star formation activity in three nearby galaxy groups: NGC 6221, NGC 3263 and NGC 2434. These groups were chosen to represent an evolutionary sequence ranging from the early stages to the late stages: from an interacting pair with tidal debris to a loose pre-processing group and finally to a more evolved system dominated by an elliptical galaxy.

We use a combination of high-resolution MeerKAT radio continuum data and WISE infrared observations to locate and measure the star formation rate in all group members. We use PAH emission as a tracer of gas heated by young stars to achieve this. In-band spectral index maps constrain the physical mechanisms driving the radio emission, while SED fitting yields the ages and masses of a subset of the galaxies.

Depending on the evolutionary stage of their group, we find that galaxies occupy distinct regions of the WISE colour–colour diagram. All systems except ESO 059–G012 follow the radio–W3PAH correlation; the latter’s deviation may indicate that it has already exhausted its gas reservoir. The data also support the idea that the Vela Cloud originated from an interaction, likely involving NGC 3263, NGC 3256B and NGC 3256C. Finally, our results are consistent with the presence of low-luminosity active galactic nuclei (AGN) in NGC 6221 and NGC 3256, as previously suggested in the literature.

Fecha y lugar: 02/12/2025 – 12:30 | Sala de Juntas
Juliana Saponara
Instituto Argentino de Radioastronomia (IAR)