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arXiv · 2105.11497

First HETDEX Spectroscopic Determinations of Ly$\alpha$ and UV Luminosity Functions at $z=2-3$: Bridging a Gap Between Faint AGN and Bright Galaxies

Yechi Zhang·Masami Ouchi·Karl Gebhardt·Erin Mentuch Cooper·Chenxu Liu·Dustin Davis·Donghui Jeong·Daniel J. Farrow·Steven L. Finkelstein·Eric Gawiser·Gary J. Hill·Yuichi Harikane·Ryota Kakuma·Viviana Acquaviva·Caitlin M. Casey·Maximilian Fabricius·Ulrich Hopp·Matt J. Jarvis·Martin Landriau·Ken Mawatari·Shiro Mukae·Yoshiaki Ono·Nao Sakai·Donald P. Schneider
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Abstract

We present Ly$\alpha$ and ultraviolet-continuum (UV) luminosity functions (LFs) of galaxies and active galactic nuclei (AGN) at $z=2.0-3.5$ determined by the un-targetted optical spectroscopic survey of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). We combine deep Subaru imaging with HETDEX spectra resulting in $11.4$ deg$^2$ of fiber-spectra sky coverage, obtaining $18320$ galaxies spectroscopically identified with Ly$\alpha$ emission, $2126$ of which host type 1 AGN showing broad (FWHM$~>1000$ km s$^{-1}$) Ly$\alpha$ emission lines. We derive the Ly$\alpha$ (UV) LF over 2 orders of magnitude covering bright galaxies and AGN in $\log L_\mathrm{Ly\alpha}/\mathrm{[erg~s^{-1}]}=43.3-45.5$ ($-27 -21$) type 1 AGN increases from $z\sim2$ to $z\sim0$ as opposed to the evolution of bright ($M_\mathrm{UV}<-21$) type 1 AGN, suggesting the AGN downsizing in the rest-frame UV luminosity.

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Yechi Zhang, Masami Ouchi, Karl Gebhardt, Erin Mentuch Cooper, Chenxu Liu, Dustin Davis, Donghui Jeong, Daniel J. Farrow, Steven L. Finkelstein, Eric Gawiser, Gary J. Hill, Yuichi Harikane, Ryota Kakuma, Viviana Acquaviva, Caitlin M. Casey, Maximilian Fabricius, Ulrich Hopp, Matt J. Jarvis, Martin Landriau, Ken Mawatari, Shiro Mukae, Yoshiaki Ono, Nao Sakai, Donald P. Schneider. 2021-05-24. First HETDEX Spectroscopic Determinations of Ly$\alpha$ and UV Luminosity Functions at $z=2-3$: Bridging a Gap Between Faint AGN and Bright Galaxies. https://doi.org/10.3847/1538-4357%2Fac1e97

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