We present the deepest medium-resolution JWST/NIRSpec spectroscopy to date of a bright Little Red Dot (LRD) AGN, Irony at z=6. 68. The data reveal broad Balmer emission from Hα-Hδ and Balmer absorption in Hα-Hε. The absorption lines are kinematically split: Hα is blueshifted while higher-order lines are redshifted suggesting complex gas kinematics; their relative ratios are inconsistent with a single, passive absorbing screen. The line depths require absorption of both the BLR and the continuum, ruling out a stellar origin, consistent with the smooth Balmer break. We fit the broad Hγ-Hα lines and find the data favor a double-Gaussian effective profile, although exponential wings are evident. Depending on the adopted profile, single-epoch virial estimates give log (M_/M_) =7. 86-8. 39 and λ ₄₃₃=1. 7-0. 4. The dynamical mass implied by the narrow lines is low log (Mdyn/M_) =9. 1, suggesting an overmassive black hole. The narrow lines display little attenuation, AV<0. 5 mag; while broad Hα/Hβ9 and the broad Balmer decrements are inconsistent with standard dust attenuation curves, suggesting collisional processes. The forbidden-line spectrum includes auroral S II and N II, and a forest of Fe II lines. Line ratios and kinematics indicate a stratified narrow-line region with both low (n ₄=420 cm^-3) and high densities (n ₄ 6. 310⁵ cm^-3). We detect metal absorption lines in both the optical (Ca II and Na I) and UV range (Fe II UV1-UV3). Our results support a picture of a compact AGN embedded in a dense, high covering-factor and stratified cocoon, with complex neutral-gas kinematics. While the choice of broad-line profile affects the virial estimates of M_, we find the effect to be of order 0. 6 dex between the different approaches.
D’Eugenio et al. (Tue,) studied this question.