Regional star-formation histories of low-surface-brightness galaxies

Characterize the star-formation histories of different regions within low-surface-brightness galaxies to determine whether their low specific star-formation rates reflect short intense episodes, continuous low-level activity, or other formation histories.

Background

The paper uses radial specific star-formation-rate profiles to infer inside-out growth in both LSBGs and high-surface-brightness galaxies. Regions below a characteristic specific star-formation rate could have formed through either short intense episodes or continuous low-level star formation, but the present-day radial specific star-formation-rate profile alone cannot distinguish between these alternatives.

The authors therefore identify spatially resolved star-formation histories as necessary for a more detailed interpretation of LSBG formation modes. This question is not resolved by the current analysis, which relies primarily on present-day mass and star-formation-rate distributions.

References

Galaxy regions with a $\mathrm{\Sigma_{sSFR}}$ lower than the characteristic value must have experienced either short intense or continuous low-level star formation activities in the past. However, this cannot be discerned from the radial distribution of $\mathrm{\Sigma_{sSFR}}$ alone, which only tells us that our LSBGs and HSBGs formed from the inside out.

— Inside-out growth and the kiloparsec-scale star formation main sequence for low-surface-brightness disk galaxies in MaNGA  (2609.02378 - Zhang et al., 2 Sep 2026) in Section 3.1, “Radial profiles”