The ALMaQUEST Survey - II. What drives central starbursts at z ∼ 0?

摘要: Starburst galaxies have elevated star formation rates (SFRs) for their stellar mass. In Ellison et al. (2018) we used integral field unit (IFU) maps of rate surface density (Sigma_SFR) and mass (Sigma_*) to show that starburst in the local universe are driven by SFRs preferentially boosted central regions. Here, present molecular gas obtained with Atacama Large Millimeter Array (ALMA) observatory 12 at z~0 drawn from Mapping Nearby Galaxies Apache Point Observatory (MaNGA) survey. The ALMA MaNGA data well matched spatial resolution, such (Sigma_H2) can be directly compared kpc-scale resolution. combination Sigma_H2, Sigma_* Sigma_SFR same resolution allow us investigate whether starbursts primarily enhancements efficiency (SFE) or increased fractions. By computing offsets resolved Kennicutt-Schmidt relation (Sigma_H2 vs. Sigma_SFR) main sequence (Sigma_* Sigma_H2), conclude primary driver is an SFE. We also enhancement accompanied a dilution O/H, consistent triggering induced metal poor inflow. These observational signatures found both undisturbed (9/12 our sample) recently merged galaxies, indicating interactions secular mechanisms contribute starbursts.