text: 111,37,1255768143596830721,135150782,Michele Ginolfi,"My new paper is out! ""CGM pollution and gas mixing by tidal stripping in a merging system at z~4.57"" <LINK> Here we show ALMA/HST+ observations of an interesting major merging system at z~4.5 (observed in ALPINE), close to a density peak of a protocluster. 1/ <LINK> ALMA reveals [CII] arising from an extended structure (~30 kpc) surrounding the system, and about 50% of the total flux resides *between* the individual galaxy components, in a sort of metal-enriched gaseous envelope with a disturbed morphology and complex kinematics. 2/ Similarly to shock-excited [CII] observed in tidal tails in local groups, we interpret our results as a possible signature of ISM stripped by strong gravitational interactions, with some contribution from material ejected by outflows and SF in small faint satellites. 3/ Our findings suggest that strong dynamical interactions in major merging systems at high-z can be an efficient mechanism for extracting gas out of galaxies and mixing the CGM with metals. This might also represent a natural channel to feed and enrich the nascent proto-ICM. 4/4 PS: the paper is submitted to A&A. Any comments are welcome! PPS: stay tuned for future ALPINE papers on the morpho-kinematical characterisation of high-z galaxies.",http://arxiv.org/abs/2004.13737,"We present ALMA observations of a merging system at z ~ 4.57, observed as a part of the ALMA Large Program to INvestigate [CII] at Early times (ALPINE) survey. Combining ALMA [CII] 158 micron and far-infrared continuum data with multi-wavelength ancillary data we find that the system is composed of two massive (Mstar >~ 10^10 Msun) star-forming galaxies experiencing a major merger (stellar mass ratio r_mass ~ 0.9) at close spatial (~13 kpc; projected) and velocity (delta_v < 300 km/s) separations, and two additional faint narrow [CII]-emitting satellites. The overall system belongs to a larger-scale protocluster environment and is coincident to one of its overdensity peaks. ALMA reveals also the presence of [CII] emission arising from a circumgalactic gas structure, extending up to a diameter-scale of ~30 kpc. Our morpho-spectral decomposition analysis shows that about 50% of the total flux resides between the individual galaxy components, in a metal-enriched gaseous envelope characterized by a disturbed morphology and complex kinematics. Similarly to observations of shock-excited [CII] emitted from tidal tails in local groups, our results can be interpreted as a possible signature of interstellar gas stripped by strong gravitational interactions, with a possible contribution from material ejected by galactic outflows and emission triggered by star formation in small faint satellites. Our findings suggest that mergers could be an efficient mechanism of gas mixing in the circumgalactic medium around high-z galaxies, and thus play a key role in the galaxy baryon cycle at early epochs. ","The ALPINE-ALMA [CII] Survey: CGM pollution and gas mixing by tidal