Credit: Gilhuly et al. 2022
Studying galaxy halos is key to understanding how galaxies form and
evolve. These diffuse, extended regions contain clues to a galaxy’s past
interactions, such as elongated streams of stars that mark the capture
of globular clusters or satellite galaxies. However, because halos are
faint and can spread a great distance beyond the luminous disk of a
galaxy, observing them can be challenging. A team led by Colleen Gilhuly
(University of Toronto, Canada) used the Dragonfly Telephoto Array to
survey a dozen nearby edge-on galaxies, pictured above and to the right,
and measure the starlight coming from each galaxy’s halo — and, by
extension, estimate the mass of the halo stars. Gilhuly
and collaborators found that the stellar halo mass fractions (the mass
of stars in the halo compared to the mass of stars in the galaxy as a
whole) varied widely among the galaxies in their sample, but the overall
mass of stars in these galaxies was correlated with the masses of their
stellar halos. To learn more about this survey of nearby galaxies, be
sure to check out the full article below!
By Kerry HensleyCitation
“Stellar Halos from the Dragonfly Edge-on Galaxies Survey,” Colleen Gilhuly et al 2022 ApJ 932 44. doi:10.3847/1538-4357/ac6750
