%0 Generic %1 tang2020lymanalpha %A Tang, Mengtao %A Stark, Daniel %A Chevallard, Jacopo %A Charlot, Stephane %A Endsley, Ryan %A Congiu, Enrico %D 2020 %K library %T Lyman-alpha spectroscopy of extreme OIII emitting galaxies at $z\simeq2-3$: Implications for Ly$\alpha$ visibility and LyC leakage at $z>6$ %U http://arxiv.org/abs/2012.04697 %X Spectroscopic observations of massive $z>7$ galaxies selected to have extremely large OIII+H$\beta$ equivalent width (EW $\sim1500$ A) have recently revealed large Ly$\alpha$ detection rates, in contrast to the weak emission seen in the general population. Why these systems are uniquely visible in Ly$\alpha$ at redshifts where the IGM is likely significantly neutral is not clear. With the goal of better understanding these results, we have begun a campaign with MMT and Magellan to measure Ly$\alpha$ in galaxies with similar OIII+H$\beta$ EWs at $z\simeq2-3$. At these redshifts, the IGM is highly ionized, allowing us to clearly disentangle how the Ly$\alpha$ properties depend on the OIII+H$\beta$ EW. Here we present Ly$\alpha$ EWs of $49$ galaxies at $z=2.2-3.7$ with intense OIII+H$\beta$ line emission (EW $=300-3000$ A). Our results demonstrate that strong Ly$\alpha$ emission (EW $>20$ A) becomes more common in galaxies with larger OIII+H$\beta$ EW, reflecting a combination of increasingly efficient ionizing photon production and enhanced transmission of Ly$\alpha$. Among the galaxies with the most extreme OIII+H$\beta$ emission (EW $\sim1500$ A), we find that strong Ly$\alpha$ emission is not ubiquitous, with only $50\%$ of our population showing Ly$\alpha$ EW $>20$ A. Our data suggest that the range of Ly$\alpha$ strengths is related to the observed ellipticity, with those systems that appear edge-on or elongated having weaker Ly$\alpha$ emission. We use these results to interpret the anomalous Ly$\alpha$ properties seen in $z>7$ galaxies with extreme OIII+H$\beta$ emission and discuss implications for the escape of ionizing radiation from these extreme line emitting galaxies.

@misc{tang2020lymanalpha, abstract = {Spectroscopic observations of massive $z>7$ galaxies selected to have extremely large [OIII]+H$\beta$ equivalent width (EW $\sim1500$ \r{A}) have recently revealed large Ly$\alpha$ detection rates, in contrast to the weak emission seen in the general population. Why these systems are uniquely visible in Ly$\alpha$ at redshifts where the IGM is likely significantly neutral is not clear. With the goal of better understanding these results, we have begun a campaign with MMT and Magellan to measure Ly$\alpha$ in galaxies with similar [OIII]+H$\beta$ EWs at $z\simeq2-3$. At these redshifts, the IGM is highly ionized, allowing us to clearly disentangle how the Ly$\alpha$ properties depend on the [OIII]+H$\beta$ EW. Here we present Ly$\alpha$ EWs of $49$ galaxies at $z=2.2-3.7$ with intense [OIII]+H$\beta$ line emission (EW $=300-3000$ \r{A}). Our results demonstrate that strong Ly$\alpha$ emission (EW $>20$ \r{A}) becomes more common in galaxies with larger [OIII]+H$\beta$ EW, reflecting a combination of increasingly efficient ionizing photon production and enhanced transmission of Ly$\alpha$. Among the galaxies with the most extreme [OIII]+H$\beta$ emission (EW $\sim1500$ \r{A}), we find that strong Ly$\alpha$ emission is not ubiquitous, with only $50\%$ of our population showing Ly$\alpha$ EW $>20$ \r{A}. Our data suggest that the range of Ly$\alpha$ strengths is related to the observed ellipticity, with those systems that appear edge-on or elongated having weaker Ly$\alpha$ emission. We use these results to interpret the anomalous Ly$\alpha$ properties seen in $z>7$ galaxies with extreme [OIII]+H$\beta$ emission and discuss implications for the escape of ionizing radiation from these extreme line emitting galaxies.}, added-at = {2020-12-10T07:23:16.000+0100}, author = {Tang, Mengtao and Stark, Daniel and Chevallard, Jacopo and Charlot, Stephane and Endsley, Ryan and Congiu, Enrico}, biburl = {https://www.bibsonomy.org/bibtex/2964a0fd7bfe5669e3bd2a07f181a6df0/gpkulkarni}, description = {Lyman-alpha spectroscopy of extreme [OIII] emitting galaxies at $z\simeq2-3$: Implications for Ly$\alpha$ visibility and LyC leakage at $z>6$}, interhash = {ce1dbe2eb8853434989a4b8f72f7bc77}, intrahash = {964a0fd7bfe5669e3bd2a07f181a6df0}, keywords = {library}, note = {cite arxiv:2012.04697Comment: 13 pages, 8 figure, submitted to MNRAS}, timestamp = {2020-12-10T07:23:16.000+0100}, title = {Lyman-alpha spectroscopy of extreme [OIII] emitting galaxies at $z\simeq2-3$: Implications for Ly$\alpha$ visibility and LyC leakage at $z>6$}, url = {http://arxiv.org/abs/2012.04697}, year = 2020 }