SIMBAD references

2014ApJ...785...43W - Astrophys. J., 785, 43 (2014/April-2)

The DiskMass survey. VIII. On the relationship between disk stability and star formation.

WESTFALL K.B., ANDERSEN D.R., BERSHADY M.A., MARTINSSON T.P.K., SWATERS R.A. and VERHEIJEN M.A.W.

Abstract (from CDS):

We study the relationship between the stability level of late-type galaxy disks and their star-formation activity using integral-field gaseous and stellar kinematic data. Specifically, we compare the two-component (gas+stars) stability parameter from Romeo & Wiegert (QRW), incorporating stellar kinematic data for the first time, and the star-formation rate estimated from 21 cm continuum emission. We determine the stability level of each disk probabilistically using a Bayesian analysis of our data and a simple dynamical model. Our method incorporates the shape of the stellar velocity ellipsoid (SVE) and yields robust SVE measurements for over 90% of our sample. Averaging over this subsample, we find a meridional shape of σz/σR = 0.51–0.25+0.36 for the SVE and, at 1.5 disk scale lengths, a stability parameter of QRW= 2.0±0.9. We also find that the disk-averaged star-formation-rate surface density (({dot}Σe,*) is correlated with the disk-averaged gas and stellar mass surface densities (Σ_e, g_ and Σ_e, *_) and anti-correlated with QRW. We show that an anti-correlation between {dot}Σe,* and QRW can be predicted using empirical scaling relations, such that this outcome is consistent with well-established statistical properties of star-forming galaxies. Interestingly, {dot}Σe,* is not correlated with the gas-only or star-only Toomre parameters, demonstrating the merit of calculating a multi-component stability parameter when comparing to star-formation activity. Finally, our results are consistent with the Ostriker et al. model of self-regulated star-formation, which predicts {dot}Σe,*/Σ_e, g_ ∝ Σ_e, *_1/2. Based on this and other theoretical expectations, we discuss the possibility of a physical link between disk stability level and star-formation rate in light of our empirical results.

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Journal keyword(s): galaxies: evolution - galaxies: kinematics and dynamics - galaxies: spiral - galaxies: star formation

Simbad objects: 28

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