The ALMaQUEST Survey: III. Scatter in the resolved star forming main sequence is primarily due to variations in star formation efficiency

Abstract

Using a sample of 11,478 spaxels in 34 galaxies with molecular gas, star formation and stellar maps taken from the ALMA-MaNGA QUEnching and STar formation (ALMaQUEST) survey, we investigate the parameters that correlate with variations in star formation rates on kpc scales. We use a combination of correlation statistics and an artificial neural network to quantify the parameters that drive both the absolute star formation rate surface density (Sigma_SFR), as well as its scatter around the resolved star forming main sequence (Delta Sigma_SFR). We find that Sigma_SFR is primarily regulated by molecular gas surface density (Sigma_H2) with a secondary dependence on stellar mass surface density (Sigma_*), as expected from an `extended Kennicutt-Schmidt relation'. However, Delta Sigma_SFR is driven primarily by changes in star formation efficiency (SFE), with variations in gas fraction playing a secondary role. Taken together, our results demonstrate that whilst the absolute rate of star formation is primarily set by the amount of molecular gas, the variation of star formation rate above and below the resolved star forming main sequence (on kpc scales) is primarily due to changes in SFE.

Accepted for publication in MNRAS

References in corpus (17)

• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• Overview of the SDSS-IV MaNGA Survey: Mapping Nearby Galaxies at Apache Point Observatory
• UV Star Formation Rates in the Local Universe
• Combined CO & Dust Scaling Relations of Depletion Time and Molecular Gas Fractions with Cosmic Time, Specific Star Formation Rate and Stellar Mass
• COLD GASS, an IRAM Legacy Survey of Molecular Gas in Massive Galaxies: II. The non-universality of the Molecular Gas Depletion Timescale
• Molecular and atomic gas along and across the main sequence of star-forming galaxies
• The impact of interactions, bars, bulges, and AGN on star formation efficiency in local massive galaxies
• Star formation is boosted (and quenched) from the inside out: radial star formation profiles from MaNGA
• The ALMaQUEST Survey: The molecular gas main sequence and the origin of the star forming main sequence
• SDSS-IV MANGA: Spatially Resolved Star Formation Main Sequence and LI(N)ER Sequence
• What shapes a galaxy? - Unraveling the role of mass, environment and star formation in forming galactic structure
• Resolved star formation and molecular gas properties of green valley galaxies: a first look with ALMA and MaNGA
• Towards a deeper understanding of the physics driving galaxy quenching -- inferring trends in the gas content via extinction
• The EDGE-CALIFA Survey: Exploring the Star Formation Law through Variable Selection
• GASP. XX. From the loose spatially-resolved to the tight global SFR-Mass relation in local spiral galaxies
• The Fine Line Between Normal and Starburst Galaxies
• Calibrating star-formation rate prescriptions at different scales (10 pc to 1 kpc) in M31

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