The origin of the LMC stellar bar: clues from the SFH of the bar and inner disk

Abstract

We discuss the origin of the LMC stellar bar by comparing the star formation histories (SFH) obtained from deep color-magnitude diagrams (CMDs) in the bar and in a number of fields in different directions within the inner disk. The CMDs, reaching the oldest main sequence turnoffs in these very crowded fields, have been obtained with VIMOS on the VLT in service mode, under very good seeing conditions. We show that the SFHs of all fields share the same patterns, with consistent variations of the star formation rate as a function of time in all of them. We therefore conclude that no specific event of star formation can be identified with the formation of the LMC bar, which instead likely formed from a redistribution of disk material that occurred when the LMC disk became bar unstable, and shared a common SFH with the inner disk thereafter. The strong similarity between the SFH of the center and edge of the bar rules out significant spatial variations of the SFH across the bar, which are predicted by scenarios of classic bar formation through buckling mechanisms.

MNRAS Letters, accepted

References in corpus (4)

• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• Outside-in disk evolution in the LMC
• Stellar Content and Recent Star Formation History of the Local Group Dwarf Irregular Galaxy IC1613
• Observational constraints to boxy/peanut bulge formation time

Cited by in corpus (7)

• APOGEE Chemical Abundance Patterns of the Massive Milky Way Satellites
• The synchronised dance of the Magellanic Clouds' star formation history
• The VMC survey -- XLIII. The spatially resolved star formation history across the Large Magellanic Cloud
• The Large Magellanic Cloud stellar content with SMASH: I. Assessing the stability of the Magellanic spiral arms
• The Second Data Release of the Survey of the MAgellanic Stellar History (SMASH)
• Role of galactic bars in the formation of spiral arms: A study through orbital and escape dynamics -- I
• Peeping into recent star formation history of the Magellanic Clouds