%0 Generic %1 yang2017lyalpha %A Yang, Huan %A Malhotra, Sangeeta %A Gronke, Max %A Rhoads, James E. %A Leitherer, Claus %A Wofford, Aida %A Jiang, Tianxing %A Dijkstra, Mark %A Tilvi, V. %A Wang, Junxian %D 2017 %K Lya emission green peas %T Ly$\alpha$ profile, dust, and prediction of Ly$\alpha$ escape fraction in Green Pea Galaxies %U http://arxiv.org/abs/1701.01857 %X We studied Lyman-$\alpha$ (Ly$\alpha$) escape in a statistical sample of 43 Green Peas with HST/COS Ly$\alpha$ spectra. Green Peas are nearby star-forming galaxies with strong OIII$łambda$5007 emission lines. Our sample is four times larger than the previous sample and covers a much more complete range of Green Pea properties. We found that about 2/3 of Green Peas are strong Ly$\alpha$ line emitters with rest-frame Ly$\alpha$ equivalent width $>20$ \AA. The Ly$\alpha$ profiles of Green Peas are diverse. The Ly$\alpha$ escape fraction, defined as the ratio of observed Ly$\alpha$ flux to intrinsic Ly$\alpha$ flux, shows anti-correlations with a few Ly$\alpha$ kinematic features -- both the blue peak and red peak velocities, the peak separations, and FWHM of the red portion of the Ly$\alpha$ profile. Using properties measured from SDSS optical spectra, we found many correlations -- Ly$\alpha$ escape fraction generally increases at lower dust reddening, lower metallicity, lower stellar mass, and higher OIII/OII ratio. We fit their Ly$\alpha$ profiles with the HI shell radiative transfer model and found Ly$\alpha$ escape fraction anti-correlates with the best-fit $N_HI$. Finally, we fit an empirical linear relation to predict Ly$\alpha$ escape fraction from the dust extinction and Ly$\alpha$ red peak velocity. The standard deviation of this relation is about 0.3 dex. This relation can be used to isolate the effect of IGM scatterings from Ly$\alpha$ escape and to probe the IGM optical depth along the line of sight of each $z>7$ Ly$\alpha$ emission line galaxy in the JWST era.

@misc{yang2017lyalpha, abstract = {We studied Lyman-$\alpha$ (Ly$\alpha$) escape in a statistical sample of 43 Green Peas with HST/COS Ly$\alpha$ spectra. Green Peas are nearby star-forming galaxies with strong [OIII]$\lambda$5007 emission lines. Our sample is four times larger than the previous sample and covers a much more complete range of Green Pea properties. We found that about 2/3 of Green Peas are strong Ly$\alpha$ line emitters with rest-frame Ly$\alpha$ equivalent width $>20$ \AA. The Ly$\alpha$ profiles of Green Peas are diverse. The Ly$\alpha$ escape fraction, defined as the ratio of observed Ly$\alpha$ flux to intrinsic Ly$\alpha$ flux, shows anti-correlations with a few Ly$\alpha$ kinematic features -- both the blue peak and red peak velocities, the peak separations, and FWHM of the red portion of the Ly$\alpha$ profile. Using properties measured from SDSS optical spectra, we found many correlations -- Ly$\alpha$ escape fraction generally increases at lower dust reddening, lower metallicity, lower stellar mass, and higher [OIII]/[OII] ratio. We fit their Ly$\alpha$ profiles with the HI shell radiative transfer model and found Ly$\alpha$ escape fraction anti-correlates with the best-fit $N_{HI}$. Finally, we fit an empirical linear relation to predict Ly$\alpha$ escape fraction from the dust extinction and Ly$\alpha$ red peak velocity. The standard deviation of this relation is about 0.3 dex. This relation can be used to isolate the effect of IGM scatterings from Ly$\alpha$ escape and to probe the IGM optical depth along the line of sight of each $z>7$ Ly$\alpha$ emission line galaxy in the JWST era.}, added-at = {2017-01-10T10:03:16.000+0100}, author = {Yang, Huan and Malhotra, Sangeeta and Gronke, Max and Rhoads, James E. and Leitherer, Claus and Wofford, Aida and Jiang, Tianxing and Dijkstra, Mark and Tilvi, V. and Wang, Junxian}, biburl = {https://www.bibsonomy.org/bibtex/2d24a01250d90a5bd929d0d3dc6ab8555/miki}, description = {[1701.01857] Ly$\alpha$ profile, dust, and prediction of Ly$\alpha$ escape fraction in Green Pea Galaxies}, interhash = {18dfda81165a6b100348936957ff9764}, intrahash = {d24a01250d90a5bd929d0d3dc6ab8555}, keywords = {Lya emission green peas}, note = {cite arxiv:1701.01857Comment: 15 pages, 11 figures, 3 tables. Submitted to ApJ. Comments welcome}, timestamp = {2017-01-10T10:03:16.000+0100}, title = {Ly$\alpha$ profile, dust, and prediction of Ly$\alpha$ escape fraction in Green Pea Galaxies}, url = {http://arxiv.org/abs/1701.01857}, year = 2017 }