N-body simulation of a major merger shows M31's extended rotating stellar disc as a stretched and warped remnant of the progenitor disc extending beyond 40 kpc.
The large-scale structure of the halo of the Andromeda galaxy II. Hierarchical structure in the Pan-Andromeda Archaeological Survey
5 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
The Pan-Andromeda Archaeological Survey is a survey of $>400$ square degrees centered on the Andromeda (M31) and Triangulum (M33) galaxies that has provided the most extensive panorama of a $L_\star$ galaxy group to large projected galactocentric radii. Here, we collate and summarise the current status of our knowledge of the substructures in the stellar halo of M31, and discuss connections between these features. We estimate that the 13 most distinctive substructures were produced by at least 5 different accretion events, all in the last 3 or 4 Gyrs. We suggest that a few of the substructures furthest from M31 may be shells from a single accretion event. We calculate the luminosities of some prominent substructures for which previous estimates were not available, and we estimate the stellar mass budget of the outer halo of M31. We revisit the problem of quantifying the properties of a highly structured dataset; specifically, we use the OPTICS clustering algorithm to quantify the hierarchical structure of M31's stellar halo, and identify three new faint structures. M31's halo, in projection, appears to be dominated by two `mega-structures', that can be considered as the two most significant branches of a merger tree produced by breaking M31's stellar halo into smaller and smaller structures based on the stellar spatial clustering. We conclude that OPTICS is a powerful algorithm that could be used in any astronomical application involving the hierarchical clustering of points. The publication of this article coincides with the public release of all PAndAS data products.
years
2026 5representative citing papers
ARTEMIS and EAGLE simulations classify L* galaxies by central BH-to-stellar-mass ratio and trace how merger history drives divergence in BH growth, star formation, and morphology, offering an explanation for the observed scatter and for MW/M31 differences.
Stellar age analysis of a large Galactic sample gives a cosmic age of 13.73 Gyr, consistent with LambdaCDM but inconsistent with some Hubble tension resolutions implying 12.9 Gyr.
Five of seven modeled M31 dwarf spheroidals show anomalously low central DM densities at 150 pc, with star formation heating disfavored as the sole cause.
citing papers explorer
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The Merger-Driven Origin of the Vast Extended Stellar Disc Around the Andromeda Galaxy
N-body simulation of a major merger shows M31's extended rotating stellar disc as a stretched and warped remnant of the progenitor disc extending beyond 40 kpc.
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Co-evolution of Supermassive Black Holes and their Host L* galaxies: implications for Milky Way and M31
ARTEMIS and EAGLE simulations classify L* galaxies by central BH-to-stellar-mass ratio and trace how merger history drives divergence in BH growth, star formation, and morphology, offering an explanation for the observed scatter and for MW/M31 differences.
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The age of the Universe from a large sample of the oldest Galactic stars
Stellar age analysis of a large Galactic sample gives a cosmic age of 13.73 Gyr, consistent with LambdaCDM but inconsistent with some Hubble tension resolutions implying 12.9 Gyr.
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It's Not Just Star Formation: A trend of low dark matter densities in the Andromeda dwarf galaxy system
Five of seven modeled M31 dwarf spheroidals show anomalously low central DM densities at 150 pc, with star formation heating disfavored as the sole cause.
- Constraints on the gravitational potential from DESI DR2 BAO and its implications for the local void scenario