%0 Generic %1 song2014hetdex %A Song, Mimi %A Finkelstein, Steven L. %A Gebhardt, Karl %A Hill, Gary J. %A Drory, Niv %A Ashby, Matthew L. N. %A Blanc, Guillermo A. %A Bridge, Joanna %A Chonis, Taylor %A Ciardullo, Robin %A Fabricius, Maximilian %A Fazio, Giovanni G. %A Gawiser, Eric %A Gronwall, Caryl %A Hagen, Alex %A Huang, Jia-Sheng %A Jogee, Shardha %A Livermore, Rachael %A Salmon, Brett %A Schneider, Donald P. %A Willner, S. P. %A Zeimann, Gregory R. %D 2014 %K emission lya nir %T The HETDEX Pilot Survey V: The Physical Origin of Lyman-alpha Emitters Probed by Near-infrared Spectroscopy %U http://arxiv.org/abs/1406.4503 %X We present the results from a VLT/SINFONI and Keck/NIRSPEC near-infrared spectroscopic survey of 16 Lyman-alpha emitters (LAEs) at $z$ = 2.1 - 2.5 in the COSMOS and GOODS-N fields discovered from the HETDEX Pilot Survey. We detect rest-frame optical nebular lines (H$\alpha$ and/or OIII$łambda$5007) for 10 of the LAEs and measure physical properties, including the star formation rate (SFR), gas-phase metallicity, gas-mass fraction, and Ly$\alpha$ velocity offset. We find that LAEs may lie below the mass-metallicity relation for continuum-selected star-forming galaxies at the same redshift. The LAEs all show velocity shifts of Ly$\alpha$ relative to the systemic redshift ranging between +85 and +296 km s$^-1$ with a mean of +180 km s$^-1$. This value is smaller than measured for continuum-selected star-forming galaxies at similar redshifts. The Ly$\alpha$ velocity offsets show a moderate correlation with the measured star formation rate (2.5$\sigma$), but no significant correlations are seen with the SFR surface density, specific SFR, stellar mass, or dynamical mass ($łesssim$ 1.5$\sigma$). Exploring the role of dust, kinematics of the interstellar medium (ISM), and geometry on the escape of Ly$\alpha$ photons, we find no signature of selective quenching of resonantly scattered Ly$\alpha$ photons. However, we also find no evidence that a clumpy ISM is enhancing the Ly$\alpha$ equivalent width. Our results suggest that the low metallicity in LAEs may be responsible for yielding an environment with a low neutral hydrogen column density as well as less dust, easing the escape of Ly$\alpha$ photons over that in continuum-selected star-forming galaxies.

@misc{song2014hetdex, abstract = {We present the results from a VLT/SINFONI and Keck/NIRSPEC near-infrared spectroscopic survey of 16 Lyman-alpha emitters (LAEs) at $z$ = 2.1 - 2.5 in the COSMOS and GOODS-N fields discovered from the HETDEX Pilot Survey. We detect rest-frame optical nebular lines (H$\alpha$ and/or [OIII]$\lambda$5007) for 10 of the LAEs and measure physical properties, including the star formation rate (SFR), gas-phase metallicity, gas-mass fraction, and Ly$\alpha$ velocity offset. We find that LAEs may lie below the mass-metallicity relation for continuum-selected star-forming galaxies at the same redshift. The LAEs all show velocity shifts of Ly$\alpha$ relative to the systemic redshift ranging between +85 and +296 km s$^{-1}$ with a mean of +180 km s$^{-1}$. This value is smaller than measured for continuum-selected star-forming galaxies at similar redshifts. The Ly$\alpha$ velocity offsets show a moderate correlation with the measured star formation rate (2.5$\sigma$), but no significant correlations are seen with the SFR surface density, specific SFR, stellar mass, or dynamical mass ($\lesssim$ 1.5$\sigma$). Exploring the role of dust, kinematics of the interstellar medium (ISM), and geometry on the escape of Ly$\alpha$ photons, we find no signature of selective quenching of resonantly scattered Ly$\alpha$ photons. However, we also find no evidence that a clumpy ISM is enhancing the Ly$\alpha$ equivalent width. Our results suggest that the low metallicity in LAEs may be responsible for yielding an environment with a low neutral hydrogen column density as well as less dust, easing the escape of Ly$\alpha$ photons over that in continuum-selected star-forming galaxies.}, added-at = {2014-06-19T08:03:06.000+0200}, author = {Song, Mimi and Finkelstein, Steven L. and Gebhardt, Karl and Hill, Gary J. and Drory, Niv and Ashby, Matthew L. N. and Blanc, Guillermo A. and Bridge, Joanna and Chonis, Taylor and Ciardullo, Robin and Fabricius, Maximilian and Fazio, Giovanni G. and Gawiser, Eric and Gronwall, Caryl and Hagen, Alex and Huang, Jia-Sheng and Jogee, Shardha and Livermore, Rachael and Salmon, Brett and Schneider, Donald P. and Willner, S. P. and Zeimann, Gregory R.}, biburl = {https://www.bibsonomy.org/bibtex/2951c289cfdbb962be8db3a381e8805fe/miki}, description = {[1406.4503] The HETDEX Pilot Survey V: The Physical Origin of Lyman-alpha Emitters Probed by Near-infrared Spectroscopy}, interhash = {e5414844ccc2e657cbfdc6867b78de73}, intrahash = {951c289cfdbb962be8db3a381e8805fe}, keywords = {emission lya nir}, note = {cite arxiv:1406.4503Comment: 26 pages, accepted for publication in ApJ}, timestamp = {2014-06-19T08:03:06.000+0200}, title = {The HETDEX Pilot Survey V: The Physical Origin of Lyman-alpha Emitters Probed by Near-infrared Spectroscopy}, url = {http://arxiv.org/abs/1406.4503}, year = 2014 }