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Title: CLEAR: Spatially Resolved Emission Lines and Active Galactic Nuclei at 0.6 < z < 1.3

We investigate spatially resolved emission-line ratios in a sample of 219 galaxies (0.6 <z< 1.3) detected using the G102 grism on the Hubble Space Telescope Wide Field Camera 3 taken as part of the CANDELS LyαEmission at Reionization survey to measure ionization profiles and search for low-luminosity active galactic nuclei (AGN). We analyze [Oiii] and Hβemission-line maps, enabling us to spatially resolve the [Oiii]/Hβemission-line ratio across the galaxies in the sample. We compare the [Oiii]/Hβratio in galaxy centers and outer annular regions to measure ionization differences and investigate the potential of sources with nuclear ionization to host AGN. We investigate some of the individual galaxies that are candidates to host strong nuclear ionization and find that they often have low stellar mass and are undetected in X-rays, as expected for low-luminosity AGN in low-mass galaxies. We do not find evidence for a significant population of off-nuclear AGN or other clumps of off-nuclear ionization. We model the observed distribution of [Oiii]/Hβspatial profiles and find that most galaxies are consistent with a small or zero difference between their nuclear and off-nuclear line ratios, but 6%–16% of galaxies in the sample are likely to host nuclear [Oiii]/Hβthat is ∼0.5 dex higher than more » in their outer regions. This study is limited by large uncertainties in most of the measured [Oiii]/Hβspatial profiles; therefore, deeper data, e.g., from deeper HST/WFC3 programs or from JWST/NIRISS, are needed to more reliably measure the spatially resolved emission-line conditions of individual high-redshift galaxies.

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Publication Date:
Journal Name:
The Astrophysical Journal
Page Range or eLocation-ID:
Article No. 37
DOI PREFIX: 10.3847
Sponsoring Org:
National Science Foundation
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