# The star formation history of the Sculptor dwarf spheroidal galaxy

## TL;DR

This study maps the star formation history of the Sculptor dwarf galaxy, revealing a radial age gradient and extended star formation in the center, challenging the idea that it is solely a relic of reionization.

## Contribution

It provides the first detailed radial analysis of Sculptor's star formation history using deep photometry, showing a gradient and extended star formation not previously documented.

## Key findings

- Inner regions have longer star formation periods (~1.5 Gyr).
- Outer regions' star formation is confined to ~0.5 Gyr.
- Sculptor continued forming stars after reionization, not just a reionization relic.

## Abstract

We present the star formation history (SFH) of the Sculptor dwarf spheroidal galaxy based on deep g,r photometry taken with DECam at the Blanco telescope, focusing our analysis on the central region of the galaxy extended up to $\sim 3$ core radii. We have investigated how the SFH changes radially, subdividing the sampled area into four regions, and have detected a clear trend of star formation. All the SFHs show a single episode of star formation, with the innermost region presenting a longer period of star formation of $\sim 1.5$ Gyr and for the outermost region the main period of star formation is confined to $\sim 0.5$ Gyr. We observe a gradient in the mean age which is found to increase going towards the outer regions. These results suggest that Sculptor continued forming stars after the reionization epoch in its central part, while in the peripheral region the majority of stars probably formed during the reionization epoch and soon after its end. From our analysis Sculptor can not be considered strictly as a fossil of the reionization epoch.