Discrete star formation events in the central Bar of the Small Magellanic Cloud

TL;DR

This study analyzes deep photometric data of the Small Magellanic Cloud, revealing at least two distinct star formation events in the last 4 billion years and identifying periods of enhanced star formation activity.

Contribution

It provides new detailed star formation history of the SMC using deep imaging and luminosity functions, highlighting discrete star formation episodes over the past several billion years.

Findings

Identification of at least two discrete star formation events 2.7-4 Gyr ago.

Detection of star formation rate enhancements at 4-6 Gyr and more recent times.

Deep photometry of over a million stars in the SMC's main body.

Abstract

We present the results of the photometric analysis of a large part of the main body of the Small Magellanic Cloud. Using the 6.5m Magellan Telescope at the Las Campanas Observatory in Chile, we have acquired deep B and I images in four fields (0.44 degree each in diameter), yielding accurate photometry for 1,068,893 stars down to 24th magnitude, with a spatial resolution of 0.20 arcsec per pixel. Colour-magnitude diagrams and (completeness corrected) luminosity functions have been constructed, yielding significant new results that indicate at least two discrete star formation events over a period from 2.7 to 4 Gyr ago. Also, we have derived star formation rates as a function of look back time and have found enhancements of SF between 4-6 Gyr and at younger ages.