We present the primary results from the Dragonfly Edge-on Galaxies Survey (DEGS), an exploration of the stellar halos of twelve nearby (d<25 Mpc) edge-on disc galaxies with the Dragonfly Telephoto Array. The edge-on orientation of these galaxies allows their stellar halos to be explored with minimal obscuration by or confusion with the much brighter disc light. Galaxies in the sample span a range of stellar masses from 109.68−1010.88M⊙. We confirm that the wide range of stellar halo mass fractions previously seen for Milky Way-mass galaxies is also found among less massive spiral galaxies. The scatter in stellar halo mass fraction is large but we do find a significant positive correlation between stellar halo mass fraction and total stellar mass when the former is measured beyond five half-mass radii. Reasonably good agreement is found with predictions from cosmological hydrodynamical simulations, although observed stellar halo fractions appear to be somewhat lower than expected from these simulations.
@article{arxiv.2204.06596,
title = {Stellar halos from The Dragonfly Edge-on Galaxies Survey},
author = {Colleen Gilhuly and Allison Merritt and Roberto Abraham and Shany Danieli and Deborah Lokhorst and Qing Liu and Pieter van Dokkum and Charlie Conroy and Johnny Greco},
journal= {arXiv preprint arXiv:2204.06596},
year = {2022}
}
Comments
35 pages plus 17 appendix pages, 26 figures, accepted for publication in ApJ