Lyman Alpha Galaxies in the Epoch of Reionization (LAGER): Spectroscopic Confirmation of Two Redshift ~ 7.0 Galaxies

Huan Yang; Leopoldo Infante; James E. Rhoads; Weida Hu; Zhenya Zheng; Sangeeta Malhotra; Junxian Wang; Felipe Barrientos; Wenyong Kang; Chunyan Jiang

arXiv · 1903.09047

Lyman Alpha Galaxies in the Epoch of Reionization (LAGER): Spectroscopic Confirmation of Two Redshift ~ 7.0 Galaxies

Huan Yang·Leopoldo Infante·James E. Rhoads·Weida Hu·Zhenya Zheng·Sangeeta Malhotra·Junxian Wang·Felipe Barrientos·Wenyong Kang·Chunyan Jiang

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Abstract

We spectroscopically confirmed two narrow-band selected redshift 7.0 Ly$\alpha$ galaxies and studied their restframe UV spectra. The Ly$\alpha$ and other UV nebular lines are very useful to confirm the galactic redshifts and diagnose the different mechanisms driving the ionizing emission. We observed two narrowband-selected $z$=7.0 Ly$\alpha$ candidates in the LAGER Chandra Deep Field South (CDFS) field with IMACS at Magellan telescope and confirmed they are Ly$\alpha$ emitters at $z$=6.924 and 6.931. In one galaxy, we also obtained deep NIR spectroscopy, which yields non-detections of the high-ionization UV nebular lines. We measured upper-limits of the ratios of CIV$\lambda$1548/Ly$\alpha$, HeII$\lambda$1640/Ly$\alpha$, OIII]$\lambda$1660/Ly$\alpha$, and CIII]$\lambda$1909/Ly$\alpha$ from the NIR spectra. These upper-limits imply that the ionizing emission in this galaxy is dominated by normal star formation instead of AGN.

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Huan Yang, Leopoldo Infante, James E. Rhoads, Weida Hu, Zhenya Zheng, Sangeeta Malhotra, Junxian Wang, Felipe Barrientos, Wenyong Kang, Chunyan Jiang. 2019-03-21. Lyman Alpha Galaxies in the Epoch of Reionization (LAGER): Spectroscopic Confirmation of Two Redshift ~ 7.0 Galaxies. https://arxiv.org/abs/1903.09047

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