%0 Generic %1 maseda2020elevated %A Maseda, Michael V. %A Bacon, Roland %A Lam, Daniel %A Matthee, Jorryt %A Brinchmann, Jarle %A Schaye, Joop %A Labbe, Ivo %A Schmidt, Kasper B. %A Boogaard, Leindert %A Bouwens, Rychard %A Cantalupo, Sebastiano %A Franx, Marijn %A Hashimoto, Takuya %A Inami, Hanae %A Kusakabe, Haruka %A Mahler, Guillaume %A Nanayakkara, Themiya %A Richard, Johan %A Wisotzki, Lutz %D 2020 %K library %T Elevated ionizing photon production efficiency in faint high-equivalent-width Lyman-alpha emitters %U http://arxiv.org/abs/2002.11117 %X While low-luminosity galaxies dominate number counts at all redshifts, their contribution to cosmic Reionization is poorly understood due to a lack of knowledge of their physical properties. We isolate a sample of 35 z~4-5 continuum-faint Lyman-alpha emitters from deep VLT/MUSE spectroscopy and directly measure their Halpha emission using stacked Spitzer/IRAC Ch. 1 photometry. Based on Hubble Space Telescope imaging, we determine that the average UV continuum magnitude is fainter than -16 (~0.01 L_star), implying a median Lyman-alpha equivalent width of 249 Angstroms. By combining the Halpha measurement with the UV magnitude we determine the ionizing photon production efficiency, xi_ion, a first for such faint galaxies. The measurement of log (xi_ion Hz/erg) = 26.28 (+0.28; -0.40) is in excess of literature measurements of both continuum- and emission line-selected samples, implying a more efficient production of ionizing photons in these lower-luminosity, Lyman-alpha-selected systems. We conclude that this elevated efficiency can be explained by stellar populations with metallicities between 4e-4 and 0.008, with light-weighted ages less than 3 Myr.

@misc{maseda2020elevated, abstract = {While low-luminosity galaxies dominate number counts at all redshifts, their contribution to cosmic Reionization is poorly understood due to a lack of knowledge of their physical properties. We isolate a sample of 35 z~4-5 continuum-faint Lyman-alpha emitters from deep VLT/MUSE spectroscopy and directly measure their Halpha emission using stacked Spitzer/IRAC Ch. 1 photometry. Based on Hubble Space Telescope imaging, we determine that the average UV continuum magnitude is fainter than -16 (~0.01 L_star), implying a median Lyman-alpha equivalent width of 249 Angstroms. By combining the Halpha measurement with the UV magnitude we determine the ionizing photon production efficiency, xi_ion, a first for such faint galaxies. The measurement of log (xi_ion [Hz/erg]) = 26.28 (+0.28; -0.40) is in excess of literature measurements of both continuum- and emission line-selected samples, implying a more efficient production of ionizing photons in these lower-luminosity, Lyman-alpha-selected systems. We conclude that this elevated efficiency can be explained by stellar populations with metallicities between 4e-4 and 0.008, with light-weighted ages less than 3 Myr.}, added-at = {2020-02-27T12:33:20.000+0100}, author = {Maseda, Michael V. and Bacon, Roland and Lam, Daniel and Matthee, Jorryt and Brinchmann, Jarle and Schaye, Joop and Labbe, Ivo and Schmidt, Kasper B. and Boogaard, Leindert and Bouwens, Rychard and Cantalupo, Sebastiano and Franx, Marijn and Hashimoto, Takuya and Inami, Hanae and Kusakabe, Haruka and Mahler, Guillaume and Nanayakkara, Themiya and Richard, Johan and Wisotzki, Lutz}, biburl = {https://www.bibsonomy.org/bibtex/2fae1fdc707aabddd5fdde56c7c7721cd/gpkulkarni}, description = {Elevated ionizing photon production efficiency in faint high-equivalent-width Lyman-alpha emitters}, interhash = {1f62a8955f5334df81fff77d61831802}, intrahash = {fae1fdc707aabddd5fdde56c7c7721cd}, keywords = {library}, note = {cite arxiv:2002.11117Comment: 12 Pages, 6 Figures; Accepted for publication in MNRAS}, timestamp = {2020-02-27T12:33:20.000+0100}, title = {Elevated ionizing photon production efficiency in faint high-equivalent-width Lyman-alpha emitters}, url = {http://arxiv.org/abs/2002.11117}, year = 2020 }