K–H₂ quasi-molecular absorption detected in the T-dwarf $\mathsf{\varepsilon}$ Indi Ba

Abstract

Context.T-type dwarfs present a broad and shallow absorption feature centred around 6950 Å in the blue wing of the K doublet at 0.77 μm which resembles in depth and shape the satellite absorption predicted by detailed collisional broadening profiles. In our previous work, the position of the predicted line satellite was however somewhat too blue compared to the observed feature.