text:   cosmological simulation",8,"['A quick summary of thoughts on our new FIRE et al. paper showing that dark-matter-free low-mass galaxies  arise naturally and fairly frequently around massive galaxies in a cosmological-volume simulation. Paper led by @jorgito__moreno using FIREbox sim\n<LINK> <LINK>', 'van Dokkum and @DanieliShany discovery of low-mass dm-poor galaxies DF2 and DF4 (red bars) v. surprising, since low-mass galaxies are usually DM-dominated.  Remarkably we find several low-mass galaxies (yellow) in these sim have less DM than stars within their stellar radii. https://t.co/h0FF88if6W', 'Every one of them is a satellite of a massive (~1.e11 Mstar) host that is on an orbit that brought it within the core of the galaxy (~10 kpc from the center).  Much more DM lost than stars. https://t.co/P6vyzZsBxy', 'Most of them have very faint tidal features https://t.co/8zlzdGkiKX', 'This work follows a long line of work that has shown that close encounters between low-mass galaxies and massive hosts could do this kind of thing:  Haslbauer et al., Carleton et al., Sales et al., etc.', 'Our sims do a very good job reproducing many properties of DF2 and DF4: velocity dispersion, sizes, etc.  We predict that ~30% of massive hosts should have a satellite that is DM deficient.', 'One thing that still concerns me about our work is that we find our objects are still fairly metal rich compared to DF2 and DF4.  Could be scatter in Fe/H vs. Mstar -- will need to discover more DM-def. galaxies to test these things!', '@azifattahi @jorgito__moreno Yes, basically.  Here is relevant section of table. https://t.co/1TLuruwFFc']",22,02,1505