Spatially Extended Low Ionization Emission Regions (LIERs) at $z\sim0.9
We present spatially resolved emission diagnostics for eight $z\sim0.9$ galaxies that demonstrate extended low ionization emission-line regions (LIERs) over kpc scales. Eight candidates are selected based on their spatial extent and emission line fluxes from slitless spectroscopic observations with...
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Main Authors | , , , , , , , , , , , |
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Format | Journal Article |
Language | English |
Published |
05.10.2018
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Subjects | |
Online Access | Get full text |
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Summary: | We present spatially resolved emission diagnostics for eight $z\sim0.9$
galaxies that demonstrate extended low ionization emission-line regions (LIERs)
over kpc scales. Eight candidates are selected based on their spatial extent
and emission line fluxes from slitless spectroscopic observations with the
HST/WFC3 G141 and G800L grisms in the well-studied GOODS survey fields. Five of
the candidates (62.5%) are matched to X-ray counterparts in the \textit{Chandra
X-Ray Observatory} Deep Fields. We modify the traditional
Baldwin-Philips-Terlevich (BPT) emission line diagnostic diagram to use
[SII]/(H$\alpha$+[NII]) instead of [NII]/H$\alpha$ to overcome the blending of
[NII] and H$\alpha$+[NII] in the low resolution slitless grism spectra. We
construct emission line ratio maps and place the individual pixels in the
modified BPT. The extended LINER-like emission present in all of our
candidates, coupled with X-Ray properties consistent with star-forming galaxies
and weak [OIII]$\lambda$5007\AA\ detections, is inconsistent with purely
nuclear sources (LINERs) driven by active galactic nuclei. While recent
ground-based integral field unit spectroscopic surveys have revealed
significant evidence for diffuse LINER-like emission in galaxies within the
local universe $(z\sim0.04)$, this work provides the first evidence for the
non-AGN origin of LINER-like emission out to high redshifts. |
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DOI: | 10.48550/arxiv.1810.02819 |