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Wide field-of-view study of the Eagle Nebula with the Fourier transform imaging spectrograph SITELLE at CFHT

We present the very first wide-field, 11 by 11 arcmin, optical spectral mapping of M16, one of the most famous star-forming regions in the Galaxy. The data were acquired with the new imaging Fourier transform spectrograph SITELLE mounted on the Canada-France-Hawaii Telescope (CFHT). We obtained three spectral cubes with R=10'000 (SN1 filter), 1500 (SN2 filter) and 600 (SN3 filter), centered on the Pillars of Creation and the HH216 flow, covering the main optical nebular emission lines: [O II]3726,29 (SN1), Hb, [O III]4959,5007 (SN2), [N II]6548,84, Ha, and [S II]6717,31 (SN3). We validate the performance, calibration, and data reduction of SITELLE, and analyze the structures in the large field-of-view in terms of their kinematics and nebular emission. We compared the SITELLE data to MUSE integral field observations and other spectroscopic and narrow-band imaging data to validate the performance of SITELLE. We computed gas-phase metallicities via the strong-line method, performed a pixel-by-pixel fit to the main emission lines to derive kinematics of the ionized gas, computed the mass-loss rate of the Eastern pillar (the Spire), and combined the SITELLE data with near-infrared narrow-band imaging to characterize the HH216 flow. The comparison with previously published fluxes demonstrates very good agreement. We disentangle the dependence of the gas-phase metallicities (derived via abundance-tracing line ratios) on the degree of ionization and obtain metallicities that are in excellent agreement with the literature. We confirm the bipolar structure of HH216, find evidence for episodic accretion from the source of the flow, and identify its likely driving source. We compute the mass-loss rate of the Spire pillar on the East side of the H II region and find excellent agreement with the correlation between the mass-loss rate and the ionizing photon flux from the nearby cluster NGC6611.