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Title: Mapping the Morphology and Kinematics of a Lyα-selected Nebula at z = 3.15 with MUSE
Abstract

Recent wide-field integral-field spectroscopy has revealed the detailed properties of high-redshift Lyαnebulae, most often targeted due to the presence of an active galactic nucleus (AGN). Here, we use VLT/MUSE to resolve the morphology and kinematics of a nebula initially identified due to strong Lyαemission atz∼ 3.2 (LABn06). Our observations reveal a two-lobed Lyαnebula, at least ∼173 pkpc in diameter, with a light-weighted centroid near a mid-infrared source (within ≈17.2 pkpc) that appears to host an obscured AGN. The Lyαemission near the AGN is also coincident in velocity with the kinematic center of the nebula, suggesting that the nebula is both morphologically and kinematically centered on the AGN. Compared to AGN-selected Lyαnebulae, the surface-brightness profile of this nebula follows a typical exponential profile at large radii (>25 pkpc), although at small radii, the profile shows an unusual dip at the location of the AGN. The kinematics and asymmetry are similar to, and the Civand Heiiupper limits are consistent with, other AGN-powered Lyαnebulae. Double-peaked and asymmetric line profiles suggest that Lyαresonant scattering may be important in this nebula. These results support the picture of the AGN being responsible for powering a Lyαnebula that is oriented roughly in the plane of the sky. Further observations will explore whether the central surface-brightness depression is indicative of either an unusual gas or dust distribution or variation in the ionizing output of the AGN over time.

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Award ID(s):
1813016
NSF-PAR ID:
10485913
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
923
Issue:
2
ISSN:
0004-637X
Format(s):
Medium: X Size: Article No. 252
Size(s):
["Article No. 252"]
Sponsoring Org:
National Science Foundation
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