Reignition of Star Formation in Dwarf Galaxies

Understand

The Local Group hosts a number of star-forming dwarf galaxies that show evidence of periods of little to no star formation.

• We use a suite of cosmological simulations to study how star formation is reignited in such galaxies.
• We focus on isolated galaxies at $z=0$ with halo masses between 9.2$\times$10$^8$ M$_\odot$ and 8.4$\times$10$^9$ M$_\odot$, where star formation is typically shut off by reionization or by supernova feedback.
• Nearly 20% of these simulated galaxies later restart star formation, due to interactions with streams of gas in the intergalactic medium, indicating that this mechanism is relatively common in this mass range and that many isolated dwarfs at $z=0$ may not have been isolated throughout their histories.