The material for galaxy halos
detected by the CU-Boulder team originally was ejected from galaxies by exploding stars known as supernovae, a product of the star formation process, Stocke of CU-Boulder's astrophysical and planetary sciences department said.
To complement holistic views of galaxy halos
, another team, led by de Jong, employs the Hubble Space Telescope to zoom in on the streams around 18 galaxies for the "Galaxy Halos
, Outer disks, Substructure, Thick disks, and Star clusters" (GHOSTS) survey.
Cosmologists believe these orphaned stars produce the diffuse, blotchy smatterings of light that make up galaxy halos
extending well beyond the outer reaches of galaxies.
This longevity suggests that tidal streams should still be observable in galaxy halos
With the new spectrograph we can see galaxy halos
out to at least 150,000 parsecs.
This indicates to astronomers how the surrounding environment influenced the formation of galaxy halos
in the early Universe.
The blue arc adds to the now widely accepted belief that small, infalling galaxies are important contributors to galaxy halos
, including the Milky Way's (S&T: May 2001, page 22).