The Gaia DR3 view of dynamical substructure in the stellar halo near the Sun. (arXiv:2206.11248v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Dodd_E/0/1/0/all/0/1">Emma Dodd</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Callingham_T/0/1/0/all/0/1">Thomas M. Callingham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Helmi_A/0/1/0/all/0/1">Amina Helmi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Matsuno_T/0/1/0/all/0/1">Tadafumi Matsuno</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ruiz_Lara_T/0/1/0/all/0/1">Tomas Ruiz-Lara</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Balbinot_E/0/1/0/all/0/1">Eduardo Balbinot</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lovdal_S/0/1/0/all/0/1">Sofie Lovdal</a>

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 Gaia DR3 data supplemented by metallicity and chemical
abundance information from LAMOST LRS and APOGEE for halo stars within 2.5 kpc
from the Sun. We utilise a single linkage-based clustering algorithm to
identify over-densities in Integrals of Motion space that could be due to
merger debris. Combined with metallicity information and chemical abundances,
we characterise these statistically significant over-densities. We find that
the local stellar halo contains 8 main dynamical groups, some of in-situ and
some of accreted origin, most of which are already known. We report the
discovery of a new substructure, which we name ED-1. In addition, we find
evidence for 9 independent smaller clumps, 4 of which are new: ED-2, 3, 4 and 5
are typically rather tight dynamically, depict a small range of metallicities,
and their abundances when available, as well as their location in Integrals of
Motion space suggest an accreted origin.

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 Gaia DR3 data supplemented by metallicity and chemical
abundance information from LAMOST LRS and APOGEE for halo stars within 2.5 kpc
from the Sun. We utilise a single linkage-based clustering algorithm to
identify over-densities in Integrals of Motion space that could be due to
merger debris. Combined with metallicity information and chemical abundances,
we characterise these statistically significant over-densities. We find that
the local stellar halo contains 8 main dynamical groups, some of in-situ and
some of accreted origin, most of which are already known. We report the
discovery of a new substructure, which we name ED-1. In addition, we find
evidence for 9 independent smaller clumps, 4 of which are new: ED-2, 3, 4 and 5
are typically rather tight dynamically, depict a small range of metallicities,
and their abundances when available, as well as their location in Integrals of
Motion space suggest an accreted origin.

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