The stellar populations of the M31 halo substructure
We present the first results from our survey of stellar substructure in the outskirts of M31 using the Advanced Camera for Surveys on board the Hubble Space Telescope. We discuss the stellar populations associated with five prominent stellar overdensities discovered during the course of our panorami...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
Institute of Physics Publishing
2005
|
| _version_ | 1797099695903866880 |
|---|---|
| author | Ferguson, AMN Johnson, R Faria, D Irwin, M Ibata, R Johnston, K Lewis, G Tanvir, N |
| author_facet | Ferguson, AMN Johnson, R Faria, D Irwin, M Ibata, R Johnston, K Lewis, G Tanvir, N |
| author_sort | Ferguson, AMN |
| collection | OXFORD |
| description | We present the first results from our survey of stellar substructure in the outskirts of M31 using the Advanced Camera for Surveys on board the Hubble Space Telescope. We discuss the stellar populations associated with five prominent stellar overdensities discovered during the course of our panoramic ground-based imaging survey with the Isaac Newton Telescope Wide-Field Camera; a sixth pointing targets a region of "clean" halo. The color-magnitude diagrams, which contain between ≈10,000 and 90,000 stars and reach 4 mag below the horizontal branch, reveal clear variations in morphology between most fields, indicating that the age and/or metallicity mix of stars is not constant at large radius. This directly confirms the existence of large-scale population inhomogeneities within the halo of M31 and lends further support to the notion that M31 has formed, at least in part, through satellite accretions. We find a striking similarity between the populations of the giant stellar stream and those of another overdensity, the NE shelf, which lies northeast of the galaxy center. If these overdensities are associated with the same population, then the difference in their red clump magnitudes implies that the NE shelf lies in front of the stream by several tens of kiloparsecs, in good agreement with recent orbit calculations for the stream progenitor. © 2005. The American Astronomical Society. All rights reserved. |
| first_indexed | 2024-03-07T05:27:15Z |
| format | Journal article |
| id | oxford-uuid:e0fd5380-1450-4489-a964-5db981b87f11 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:27:15Z |
| publishDate | 2005 |
| publisher | Institute of Physics Publishing |
| record_format | dspace |
| spelling | oxford-uuid:e0fd5380-1450-4489-a964-5db981b87f112022-03-27T09:51:14ZThe stellar populations of the M31 halo substructureJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e0fd5380-1450-4489-a964-5db981b87f11EnglishSymplectic Elements at OxfordInstitute of Physics Publishing2005Ferguson, AMNJohnson, RFaria, DIrwin, MIbata, RJohnston, KLewis, GTanvir, NWe present the first results from our survey of stellar substructure in the outskirts of M31 using the Advanced Camera for Surveys on board the Hubble Space Telescope. We discuss the stellar populations associated with five prominent stellar overdensities discovered during the course of our panoramic ground-based imaging survey with the Isaac Newton Telescope Wide-Field Camera; a sixth pointing targets a region of "clean" halo. The color-magnitude diagrams, which contain between ≈10,000 and 90,000 stars and reach 4 mag below the horizontal branch, reveal clear variations in morphology between most fields, indicating that the age and/or metallicity mix of stars is not constant at large radius. This directly confirms the existence of large-scale population inhomogeneities within the halo of M31 and lends further support to the notion that M31 has formed, at least in part, through satellite accretions. We find a striking similarity between the populations of the giant stellar stream and those of another overdensity, the NE shelf, which lies northeast of the galaxy center. If these overdensities are associated with the same population, then the difference in their red clump magnitudes implies that the NE shelf lies in front of the stream by several tens of kiloparsecs, in good agreement with recent orbit calculations for the stream progenitor. © 2005. The American Astronomical Society. All rights reserved. |
| spellingShingle | Ferguson, AMN Johnson, R Faria, D Irwin, M Ibata, R Johnston, K Lewis, G Tanvir, N The stellar populations of the M31 halo substructure |
| title | The stellar populations of the M31 halo substructure |
| title_full | The stellar populations of the M31 halo substructure |
| title_fullStr | The stellar populations of the M31 halo substructure |
| title_full_unstemmed | The stellar populations of the M31 halo substructure |
| title_short | The stellar populations of the M31 halo substructure |
| title_sort | stellar populations of the m31 halo substructure |
| work_keys_str_mv | AT fergusonamn thestellarpopulationsofthem31halosubstructure AT johnsonr thestellarpopulationsofthem31halosubstructure AT fariad thestellarpopulationsofthem31halosubstructure AT irwinm thestellarpopulationsofthem31halosubstructure AT ibatar thestellarpopulationsofthem31halosubstructure AT johnstonk thestellarpopulationsofthem31halosubstructure AT lewisg thestellarpopulationsofthem31halosubstructure AT tanvirn thestellarpopulationsofthem31halosubstructure AT fergusonamn stellarpopulationsofthem31halosubstructure AT johnsonr stellarpopulationsofthem31halosubstructure AT fariad stellarpopulationsofthem31halosubstructure AT irwinm stellarpopulationsofthem31halosubstructure AT ibatar stellarpopulationsofthem31halosubstructure AT johnstonk stellarpopulationsofthem31halosubstructure AT lewisg stellarpopulationsofthem31halosubstructure AT tanvirn stellarpopulationsofthem31halosubstructure |