Duality in spatially resolved star formation relations in local LIRGs

DOI: 
10.1051/0004-6361/202141963
Publication date: 
08/03/2022
Main author: 
Sánchez-García, M.
IAA authors: 
Cazzoli, S.
Authors: 
Sánchez-García, M.;Pereira-Santaella, M.;García-Burillo, S.;Colina, L.;Alonso-Herrero, A.;Villar-Martín, M.;Saito, T.;Díaz-Santos, T.;Piqueras López, J.;Arribas, S.;Bellocchi, E.;Cazzoli, S.;Labiano, A.
Journal: 
Astronomy and Astrophysics
Refereed: 
Yes
Publication type: 
Article
Volume: 
659
Pages: 
A102
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 Paα HST/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 &lt; 0.85 kpc), shows higher gas and SF 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 ∼ 1 kpc). Despite the scatter, the SF efficiency of the galaxies with dual behaviour increases with increasing boundedness as measured by the b parameter (b≡ Σ<SUB>H2</SUB>/σ<SUP>2</SUP> ∝ α<SUB>vir</SUB><SUP>−1</SUP>). 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.
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2022A&A...659A.102S/abstract
ADS Bibcode: 
2022A&A...659A.102S
Keywords: 
galaxies: star formation;galaxies: ISM;infrared: galaxies;Astrophysics - Astrophysics of Galaxies