Program: GN-2021B-Q-114

HATLAS J084933 (Ivison et al. 2013) at z=2.41 is the most luminous starbursting galaxy known in the Universe. We propose NIFS IFU deep AO follow-up to understand the internal dynamics in Halpha/NII, complementing ALMA and PdBI data, to probe the triggering mechanisms. A fortuitous nearby guide star (R~14.5 at 10" offset) allows LGS mapping of bright Halpha/[NII] lines. These observations will allow us to probe merger versus disk by: 1) studying the distribution and kinematics of ionized gas through resolved Hα/[OIII] emission lines, 2) deriving metallicity gradients, and to 3) search for AGN and/or star formation driven outflows and measure their energetics. The observations will also serve as a pathfinder for TMT. (This proposal was thrice awarded Grade-2 and 1 time in 16a, 17a, 19b semesters, but has failed to gain useful data due to laser/ALTAIR problems. Two hours of data was taken in the last program, right before ALTAIR failed, and data had FWHM ranging 0.2"-0.4").