The EDGE-CALIFA survey: exploring the star formation law through variable selection

Abstract

<jats:title>ABSTRACT</jats:title> <jats:p>We present a multilinear analysis to determine the significant predictors of star formation in galaxies using the combined EDGE-CALIFA sample of galaxies. We analyse 1845 kpc-scale lines of sight across 39 galaxies with molecular line emission measurements from EDGE combined with optical IFU data drawn from CALIFA. We use the Least Absolute Shrinkage and Selection Operator (LASSO) to identify significant factors in predicting star formation rates. We find that the local star formation rate surface density is increased by higher molecular gas surface densities and stellar surface densities. In contrast, we see lower star formation rates in systems with older stellar populations, higher gas- and stellar-phase metallicities and larger galaxy masses. We also find a significant increase in star formation rate with galactocentric radius normalized by the disc scale length, which suggests additional parameters regulating star formation rate not explored in this study.</jats:p>

The ALMaQUEST survey – III. Scatter in the resolved star-forming main sequence is primarily due to variations in star formation efficiency

“…Dey et al (2019)'s result therefore contrasts with the conclusions of our study, and imply that, at kpc-scales, the rSFMS is more fundamental than the Kennicutt-Schmidt law. The results of Dey et al (2019) are surprising in light of the well-established link between gas and star formation and are also in conflict with Lin et al (2019), who conclude that the rSFMS is largely due to the more fundamental -H 2 and H 2 -SFR relations.…”

“…Secondly, Dey et al (2019) combine IFU data from the Calar Alto Legacy Integral Field Area (CALIFA, Sánchez et al 2012) survey, with interferometric observations of CO, to achieve a data set that is similar in its range of physical variables to the ALMaQUEST sample studied herein. Even with the inclusion of molecular gas maps, Dey et al (2019) agree with the conclusion of Bluck et al (2019b) on the primary importance of in determining SFR , ranking it above H 2 . Dey et al (2019)'s result therefore contrasts with the conclusions of our study, and imply that, at kpc-scales, the rSFMS is more fundamental than the Kennicutt-Schmidt law.…”

“…There is clear evidence that there can be significant internal variations in SFE within a given galaxy (e.g. Leroy et al 2013;Utomo et al 2017;Tomicic et al 2019), and that the regulation of star formation happens on local, not global scales (Bluck et al 2019b;Dey et al 2019). Studies that investigate correlations in global data will average over these internal differences, blurring the underlying physical relationships.…”

The EDGE-CALIFA survey: exploring the role of molecular gas on galaxy star formation quenching

“…On average, τ dep,mol appears to decrease moving from early-to late-type systems (Colombo et al 2018), following the decrease in shear (Davis et al 2014;Colombo et al 2018) as described by the morphological quenching scenario (however, see Koyama et al 2019). The molecular depletion time is also seen to decrease with stellar surface density and increase with molecular gas velocity dispersion (Dey et al 2019). This might indicate that τ dep,mol is longer for bulged systems, and where gas is less gravitationally bound (as the gas boundness is proportional to Σ mol /σ CO , i.e.…”

From Global to Spatially Resolved in Low-Redshift Galaxies

“…Saintonge et al 2011) ; the metal content of the ISM that affects the cooling; or (vi) a combination of all of them (e.g. Dey et al 2019). Fig.…”