Duality in spatially resolved star-formation relations in local LIRGs

Abstract

We analyse the star formation (SF) relations in a sample of 16 nearby luminous infrared galaxies (LIRGs) with more than 2800 regions defined on scales of 90 to 500 pc. We used ALMA to map the distribution of the cold molecular gas traced by the J = 2-1 line of CO and archival PaαHST/NICMOS imaging to trace the recent SF. In four objects, we find two different branches in the Kennicutt-Schmidt relation at 90 pc scales, suggesting the existence of a duality in this relation. The two branches correspond to two different dynamical environments within each galaxy. One branch, which corresponds to the central region of these galaxies 90% of the regions are located at radii < 0.85 kpc), shows higher gas and star formation rate surface densities with higher velocity dispersion. The other branch, which shows lower molecular gas and SF rate surface densities, corresponds to the more external disk regions (r $\sim$ 1 kpc). Despite the scatter, the SF efficiency of the galaxies with a dual behaviour increases with increasing boundedness as measured by the b parameter (b $\equiv$ ${\Sigma }_{H_2}$/${\sigma }^2$ $\propto$ ${\alpha }_{vir}^{-1}$). At larger spatial scales (250 and 500 pc), the duality disappears. The rest of the sample does not show evidence of this dual behaviour at any scale.

Accepted for publication in A&A, 28 pages, 10 figures, 5 tables

References in corpus (8)

• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• Near-Infrared and Star-forming properties of Local Luminous Infrared Galaxies
• Cloud Scale ISM Structure and Star Formation in M51
• Turbulence and star formation efficiency in molecular clouds: solenoidal versus compressive motions in Orion B
• Star formation scaling relations at ~100 pc from PHANGS: Impact of completeness and spatial scale
• The resolved star-formation relation in nearby active galactic nuclei
• High-velocity extended molecular outflow in the star-formation dominated luminous infrared galaxy ESO 320-G030
• Are local ULIRGs powered by AGN? The sub-kpc view of the 220 GHz continuum. PUMA II

Cited by in corpus (12)

• A high angular resolution view of the PAH emission in Seyfert galaxies using JWST/MRS data
• Insight into the Starburst Nature of Galaxy GN-z11 with JWST MIRI Spectroscopy
• Characterizing Compact 15-33 GHz Radio Continuum Sources in Local U/LIRGs
• Enhanced Star Formation Efficiency in the Central Regions of Nearby Quasars Hosts
• High-resolution ALMA study of CO (2-1) line and dust continuum emissions in cluster galaxies at z = 1.46
• Compact molecular gas emission in local LIRGs among low- and high-z galaxies
• Molecular gas and star formation in nearby starburst galaxy mergers
• Clumpy star formation and an obscured nuclear starburst in the luminous dusty z=4 galaxy GN20 seen by MIRI/JWST
• Extended high-ionization [MgIV] emission tracing widespread shocks in starbursts seen by JWST /NIRSpec
• A spectacular galactic scale magnetohydrodynamic powered wind in ESO 320-G030
• The Arp 240 Galaxy Merger: A Detailed Look at the Molecular Kennicutt-Schmidt Star Formation Law on Sub-kpc Scales
• Spatially Resolved Star Formation relations in local LIRGs along the complete merger sequence