The origin and distribution of diffuse HI in the close interacting MHONGOOSE galaxy systems

We present the deepest ̋I observations of two systems with D_ łeq 100,kpc and Δ v_ łeq 200,̨ms in the MHONGOOSE survey. The MeerKAT observations are characterised by 3σ proj sys = 10 17.9 $,̧m over 16,̨ms at 4,kpc scales. The new data have enabled us to detect ̋I in seven galaxies: the interacting NGC,3511/3513 pair in one field and an interacting triplet (NGC,4781, NGC,4790 and UGCA,308), along with two new (2MASX,J1255 and MKT,25413) dwarf satellites in the second field. Six galaxies lie on the star-forming main sequence and their ̋I gas fractions are typical for such systems. In contrast, MKT,25413 exhibits log( . We find more ̋I beyond the tidal radius of the galaxies with the more recent fly-bys and we surmise that the mild environmental interactions in the close systems have the capacity to pull the diffuse ̋I out of the disc and redistribute it. The gas is not in equilibrium, although it remains bound and is in the process of falling back onto the disc. = 5.7, which is the lowest detected of a galaxy that is not a Milky Way satellite. This low-surface-brightness dwarf galaxy shows an anomalously low level of star formation and low ̋I fraction for its stellar mass. We also found a ubiquitous low column density ̋I surrounding the galaxies, which is a likely consequence of mild tidal interactions from fly-bys in the past few hundred megayears. We derive the stellar and ̋a kinematics from VLT/MUSE observations and the H_2 kinematics from ALMA observations. The kinematics of the stellar and multiphase (̋I, H_2 and ̋a) interstellar medium of the interacting galaxies reveal an ordered rotation and the atomic-to-molecular gas ratios are indistinguishable from star-forming field galaxies. The stellar morphology of all the interacting galaxies (apart from the low-mass dwarf UGCA,308) does not show any major disruptions and there is no stellar component associated with the ̋I tails, bridges or clouds in the intra-group mediums, down to μ_g = 29,mag,arcsec$^ -2