Overview
- The peer-reviewed Nature Astronomy paper published Monday reports JWST measurements showing XMM-VID1-2075, seen as it was 12 billion years ago, lacks any ordered rotation.
- XMM-VID1-2075 sits at redshift 3.449 and is already massive and quiescent, with several times the Milky Way’s stars and no ongoing star formation.
- Using Webb’s NIRSpec integral-field spectrograph to map motion in three similar galaxies, the team found one clear rotator, one irregular system, and this galaxy dominated by random stellar speeds.
- The authors propose a collision of two counter-rotating galaxies as a plausible cause for the lost spin, citing a patch of extra light beside the system that hints at a recent interaction.
- Because theory expects such slow rotators to form much later through many mergers, the team will search for more early examples and compare the counts with simulations to test galaxy-formation models.