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SUMMARY:JWST reveals galaxy mergers driving Lyman-alpha emission at z &gt\
 ;7 - Callum Witten
DTSTART:20230215T131500Z
DTEND:20230215T134000Z
UID:TALK197278@talks.cam.ac.uk
CONTACT:Hannah Uebler
DESCRIPTION:One of the key\, unsolved questions in modern-day astronomy re
 gards the sources of the ionizing photons that drove reionization. Recent 
 debates focus on whether a hard radiation field emanating from a single ga
 laxy\, or an enhanced radiation field provided by an overdensity of associ
 ated objects can produce the required ionizing photons to create the ioniz
 ed bubbles that are observed at z >7. Observations of Lyman-alpha emitters
  (LAEs) resident in significant overdensities (protoclusters) have been co
 mplicated by the detection of AGN candidates additionally present within m
 any of these bubbles. However\, we present results from JWST/NIRCam imagin
 g that reveal\, for the first time\, resolved z >7 observations of LAEs\, 
 giving new insights into their intrinsic properties. These new observation
 s indicate all three known LAEs at z >7\, that have been observed by NIRCa
 m\, are undergoing mergers that were previously unresolved by HST. Combini
 ng these results with simulations of interacting systems we postulate a th
 ird solution to this unsolved mystery – Lya emission driven by interacti
 ons with a companion. 
LOCATION:The Hoyle Lecture Theatre + Zoom 
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