Testing Feedback Regulated Star Formation in Gas Rich, Turbulent Disk Galaxies. (arXiv:1811.03108v1 [astro-ph.GA])

Testing Feedback Regulated Star Formation in Gas Rich, Turbulent Disk Galaxies. (arXiv:1811.03108v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Fisher_D/0/1/0/all/0/1">Deanne B Fisher</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bolatto_A/0/1/0/all/0/1">Alberto D. Bolatto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+White_H/0/1/0/all/0/1">Heidi White</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Glazebrook_K/0/1/0/all/0/1">Karl Glazebrook</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Abraham_R/0/1/0/all/0/1">Roberto G. Abraham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Obreschkow_D/0/1/0/all/0/1">Danail Obreschkow</a>

In this paper we compare the molecular gas depletion times and mid-plane
hydrostatic pressure in turbulent, star forming disk galaxies to internal
properties of these galaxies. For this analysis we use 17 galaxies from the
DYNAMO sample of nearby ($zsim0.1$) turbulent disks. We find a strong
correlation, such that galaxies with lower molecular gas depletion time
(t_{dep}) have higher gas velocity dispersion ($sigma$). Within the scatter of
our data, our observations are consistent with the prediction that depletion
time is inversely proportionate to velocity dispersion made in theories of
feedback-regulated star formation. We also show a strong, single power-law
correlation between mid-plane pressure (P) and star formation rate surface
density (Sigma_{SFR}), which extends for 6 orders of magnitude in pressure.
Disk galaxies with lower pressure are found to be roughly in agreement with
theoretical predictions. However, in galaxies with high pressure we find
P/Sigma_{SFR} values that are significantly larger than theoretical
predictions. Our observations could be explained with any of the following: (1)
the correlation of Sigma_{SFR}-P is significantly sub-linear; (2) the momentum
injected from star formation feedback (so-called p*/m*) is not a single,
universal value; or (3) alternate sources of pressure support are important in
gas-rich disk galaxies. Finally using published survey results, we find that
our results are consistent with the cosmic evolution of t_{dep}(z) and velocity
dispersion. Our interpretation of these results is that the cosmic evolution of
t_{dep} may be regulated not just by the supply of gas, but also the internal
regulation of star formation via feedback.

In this paper we compare the molecular gas depletion times and mid-plane
hydrostatic pressure in turbulent, star forming disk galaxies to internal
properties of these galaxies. For this analysis we use 17 galaxies from the
DYNAMO sample of nearby ($zsim0.1$) turbulent disks. We find a strong
correlation, such that galaxies with lower molecular gas depletion time
(t_{dep}) have higher gas velocity dispersion ($sigma$). Within the scatter of
our data, our observations are consistent with the prediction that depletion
time is inversely proportionate to velocity dispersion made in theories of
feedback-regulated star formation. We also show a strong, single power-law
correlation between mid-plane pressure (P) and star formation rate surface
density (Sigma_{SFR}), which extends for 6 orders of magnitude in pressure.
Disk galaxies with lower pressure are found to be roughly in agreement with
theoretical predictions. However, in galaxies with high pressure we find
P/Sigma_{SFR} values that are significantly larger than theoretical
predictions. Our observations could be explained with any of the following: (1)
the correlation of Sigma_{SFR}-P is significantly sub-linear; (2) the momentum
injected from star formation feedback (so-called p*/m*) is not a single,
universal value; or (3) alternate sources of pressure support are important in
gas-rich disk galaxies. Finally using published survey results, we find that
our results are consistent with the cosmic evolution of t_{dep}(z) and velocity
dispersion. Our interpretation of these results is that the cosmic evolution of
t_{dep} may be regulated not just by the supply of gas, but also the internal
regulation of star formation via feedback.

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