BibTeX

@article{2502.14972v1,
Author        = {Andrea Sante and Daisuke Kawata and Andreea S. Font and Robert J. J. Grand},
Title         = {GalactiKit: reconstructing mergers from $z=0$ debris using
  simulation-based inference in Auriga},
Eprint        = {2502.14972v1},
ArchivePrefix = {arXiv},
PrimaryClass  = {astro-ph.GA},
Abstract      = {We present GalactiKit, a data-driven methodology for estimating the lookback
infall time, stellar mass, halo mass and mass ratio of the disrupted
progenitors of Milky Way-like galaxies at the time of infall. GalactiKit uses
simulation-based inference to extract the information on galaxy formation
processes encoded in the Auriga cosmological MHD simulations of Milky Way-mass
halos to create a model that relates the properties of mergers to those of the
corresponding merger debris at $z=0$. We investigate how well GalactiKit can
reconstruct the merger properties given the dynamical, chemical, and the
combined chemo-dynamical information of debris. For this purpose, three models
were implemented considering the following properties of merger debris: (a)
total energy and angular momentum, (b) iron-to-hydrogen and alpha-to-iron
abundance ratios, and (c) a combination of all of these. We find that the
kinematics of the debris can be used to trace the lookback time at which the
progenitor was first accreted into the main halo. However, chemical information
is necessary for inferring the stellar and halo masses of the progenitors. In
both models (b) and (c), the stellar masses are predicted more accurately than
the halo masses, which could be related to the scatter in the stellar mass-halo
mass relation. Model (c) provides the most accurate predictions for the merger
parameters, which suggests that combining chemical and dynamical data of debris
can significantly improve the reconstruction of the Milky Way's assembly
history.},
Year          = {2025},
Month         = {Feb},
Url           = {http://arxiv.org/abs/2502.14972v1},
File          = {2502.14972v1.pdf}
}