Publications (10)
Characterisation of local halo building blocks: Thamnos and Sequoia
Emma Dodd, Tomás Ruiz-Lara, Amina Helmi +5
A crucial aspect of galaxy evolution is the pace at which galaxies build up their mass. We investigate this hierarchical assembly by uncovering and timing accretion events experien…
High-precision chemical abundances of Galactic building blocks. II. Revisiting the chemical distinctness of the Helmi streams
Tadafumi Matsuno, Emma Dodd, Helmer H. Koppelman +6
Context: The Helmi streams are a kinematic substructure whose progenitor is likely a dwarf galaxy. Although 20 years have passed since their discovery, it is still unclear whether…
The Gaia DR3 view of dynamical substructure in the stellar halo near the Sun
Emma Dodd, Thomas M. Callingham, Amina Helmi +4
The debris from past merger events is expected and, to some extent, known to populate the stellar halo near the Sun. We aim to identify and characterise such merger debris using Ga…
Chronology of our Galaxy from Gaia colour-magnitude diagram fitting (ChronoGal) -- III. Age and metallicity distribution of Gaia-Sausage-Enceladus stars near the Sun
Yllari K. González-Koda, Tomás Ruiz-Lara, Carme Gallart +14
Context. Gaia-Sausage-Enceladus is considered the last major merger that contributed to the formation of the Milky Way. Its remnants dominate the nearby accreted stellar halo of th…
Substructure in the stellar halo near the Sun. II. Characterisation of independent structures
Tomás Ruiz-Lara, Tadafumi Matsuno, S. Sofie Lövdal +3
In Lövdal et al, we presented a data-driven method for clustering in Integrals of Motion space and applied it to a large sample of nearby halo stars with 6D phase-space informatio…
Chemical characterisation of small substructures in the local stellar halo
Emma Dodd, Tadafumi Matsuno, Amina Helmi +5
The local stellar halo of the Milky Way is known to contain the debris from accreted dwarf galaxies and globular clusters, in the form of stellar streams and over-densities in the…
Substructure in the stellar halo near the Sun. I. Data-driven clustering in Integrals of Motion space
S. Sofie Lövdal, Tomás Ruiz-Lara, Helmer H. Koppelman +3
Aims: Develop a data-driven and statistically based method for finding such clumps in Integrals of Motion space for nearby halo stars and evaluating their significance robustly. Me…
Unevolved Li-rich stars at low metallicity: a possible formation pathway through novae
Tadafumi Matsuno, Alex Kemp, Ataru Tanikawa +7
A small fraction of low-mass stars have been found to have anomalously high Li abundances. Although it has been suggested that mixing during the red giant branch phase can lead to…
Substructures, Resonances and debris streams
Emma Dodd, Amina Helmi, Helmer H. Koppelman
The local stellar halo of the Milky Way contains the debris from several past accretion events. Here we study in detail the structure and properties of nearby debris associated wit…
Chronology of our Galaxy from Gaia colour-magnitude diagram fitting (ChronoGal) II. Unveiling the formation and evolution of the kinematically selected Thick and Thin Discs
Emma Fernández-Alvar, Tomás Ruiz-Lara, Carme Gallart +16
Understanding the formation and evolution of the Milky Way's thin and thick discs is crucial to galaxy formation studies. We derive age and metallicity distributions of the kinemat…