| Title: |
The outer halo globular cluster system of M31 – III. Relationship to the stellar halo |
| Authors: |
Mackey, AD; Ferguson, AMN; Huxor, AP; Veljanoski, J; Lewis, GF; McConnachie, AW; Martin, NF; Ibata, RA; Irwin, MJ; Côté, P; Collins, MLM; Tanvir, NR; Bate, NF |
| Publisher Information: |
//doi.org/10.1093/mnras/stz072; Oxford University Press (OUP) |
| Publication Year: |
2019 |
| Collection: |
Apollo - University of Cambridge Repository |
| Subject Terms: |
5109 Space Sciences; 5107 Particle and High Energy Physics; 5101 Astronomical Sciences; 51 Physical Sciences |
| Description: |
We utilize the final catalogue from the Pan-Andromeda Archaeological Survey to investigate the links between the globular cluster system and field halo in M31 at projected radii Rproj = 25–150 kpc. In this region the cluster radial density profile exhibits a power-law decline with index Γ = −2.37 ± 0.17, matching that for the stellar halo component with [Fe/H] < −1.1. Spatial density maps reveal a striking correspondence between the most luminous substructures in the metal-poor field halo and the positions of many globular clusters. By comparing the density of metal-poor halo stars local to each cluster with the azimuthal distribution at commensurate radius, we reject the possibility of no correlation between clusters and field overdensities at $99.95{{\ \rm per\ cent}}$ significance. We use our stellar density measurements and previous kinematic data to demonstrate that ${\approx }35\hbox{--}60{{\ \rm per\ cent}}$ of clusters exhibit properties consistent with having been accreted into the outskirts of M31 at late times with their parent dwarfs. Conversely, at least ${\sim }40{{\ \rm per\ cent}}$ of remote clusters show no evidence for a link with halo substructure. The radial density profile for this subgroup is featureless and closely mirrors that observed for the apparently smooth component of the metal-poor stellar halo. We speculate that these clusters are associated with the smooth halo; if so, their properties appear consistent with a scenario where the smooth halo was built up at early times via the destruction of primitive satellites. In this picture the entire M31 globular cluster system outside Rproj = 25 kpc comprises objects accumulated from external galaxies over a Hubble time of growth. |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
https://www.repository.cam.ac.uk/handle/1810/291994 |
| DOI: |
10.17863/CAM.39147 |
| Availability: |
https://www.repository.cam.ac.uk/handle/1810/291994; https://doi.org/10.17863/CAM.39147 |
| Rights: |
All rights reserved ; http://purl.org/NET/rdflicense/allrightsreserved |
| Accession Number: |
edsbas.7CB72B07 |
| Database: |
BASE |