%0 Generic %1 jaskot2015stars %A Jaskot, A. E. %A Oey, M. S. %A Salzer, J. J. %A Van Sistine, A. %A Bell, E. F. %A Haynes, M. P. %D 2015 %K HI alfalfa fraction mass starburst %T From HI to Stars: HI Depletion in Starbursts and Star-Forming Galaxies in the ALFALFA H-alpha Survey %U http://arxiv.org/abs/1506.05081 %X HI in galaxies traces the fuel for future star formation and reveals the effects of feedback on neutral gas. Using a statistically uniform, HI-selected sample of 565 galaxies from the ALFALFA H-alpha survey, we explore HI properties as a function of star formation activity. ALFALFA H-alpha provides R-band and H-alpha imaging for a volume-limited subset of the 21-cm ALFALFA survey. We identify eight starbursts based on H-alpha equivalent width and six with enhanced star formation relative to the main sequence. Both starbursts and non-starbursts have similar HI to stellar mass ratios (MHI/M*), which suggests that feedback is not depleting the starbursts' HI. Consequently, the starbursts do have shorter HI depletion times (t_dep), implying more efficient HI-to-H2 conversion. While major mergers likely drive this enhanced efficiency in some starbursts, the lowest mass starbursts may experience periodic bursts, consistent with enhanced scatter in t_dep at low M*. Two starbursts appear to be pre-coalescence mergers; their elevated MHI/M* suggest that HI-to-H2 conversion is still ongoing at this stage. By comparing with the GASS sample, we find that t_dep anti-correlates with stellar surface density for disks, while spheroids show no such trend. Among early-type galaxies, t_dep does not correlate with bulge-to-disk ratio; instead, the gas distribution may determine the star formation efficiency. Finally, the weak connection between galaxies' specific star formation rates and MHI/M* contrasts with the well-known correlation between MHI/M* and color. We show that dust extinction can explain the HI-color trend, which may arise from the relationship between M*, MHI, and metallicity.

@misc{jaskot2015stars, abstract = {HI in galaxies traces the fuel for future star formation and reveals the effects of feedback on neutral gas. Using a statistically uniform, HI-selected sample of 565 galaxies from the ALFALFA H-alpha survey, we explore HI properties as a function of star formation activity. ALFALFA H-alpha provides R-band and H-alpha imaging for a volume-limited subset of the 21-cm ALFALFA survey. We identify eight starbursts based on H-alpha equivalent width and six with enhanced star formation relative to the main sequence. Both starbursts and non-starbursts have similar HI to stellar mass ratios (MHI/M*), which suggests that feedback is not depleting the starbursts' HI. Consequently, the starbursts do have shorter HI depletion times (t_dep), implying more efficient HI-to-H2 conversion. While major mergers likely drive this enhanced efficiency in some starbursts, the lowest mass starbursts may experience periodic bursts, consistent with enhanced scatter in t_dep at low M*. Two starbursts appear to be pre-coalescence mergers; their elevated MHI/M* suggest that HI-to-H2 conversion is still ongoing at this stage. By comparing with the GASS sample, we find that t_dep anti-correlates with stellar surface density for disks, while spheroids show no such trend. Among early-type galaxies, t_dep does not correlate with bulge-to-disk ratio; instead, the gas distribution may determine the star formation efficiency. Finally, the weak connection between galaxies' specific star formation rates and MHI/M* contrasts with the well-known correlation between MHI/M* and color. We show that dust extinction can explain the HI-color trend, which may arise from the relationship between M*, MHI, and metallicity.}, added-at = {2015-06-17T09:56:07.000+0200}, author = {Jaskot, A. E. and Oey, M. S. and Salzer, J. J. and Van Sistine, A. and Bell, E. F. and Haynes, M. P.}, biburl = {https://www.bibsonomy.org/bibtex/2fb42b482030174e615b330f29d88ecc2/miki}, description = {[1506.05081] From HI to Stars: HI Depletion in Starbursts and Star-Forming Galaxies in the ALFALFA H-alpha Survey}, interhash = {bc367e445d3b95ddf7634fb822cbe0bb}, intrahash = {fb42b482030174e615b330f29d88ecc2}, keywords = {HI alfalfa fraction mass starburst}, note = {cite arxiv:1506.05081Comment: Accepted for publication in ApJ. 27 pages, 22 figures}, timestamp = {2015-06-17T09:56:07.000+0200}, title = {From HI to Stars: HI Depletion in Starbursts and Star-Forming Galaxies in the ALFALFA H-alpha Survey}, url = {http://arxiv.org/abs/1506.05081}, year = 2015 }