Solitary dwarf galaxy groups as tracers of dark matter halos in the local Universe
Abstract
In ΛCDM cosmology, galaxies and clusters form within dark matter halos and merge in the hierarchical assembly paradigm to form massive systems. Using the released optical survey data, we searched for groups composed solely of dwarf galaxies, each with a stellar mass M*<109.5 M⊙. We identified 14 dwarf galaxy groups with at least 5 dwarf galaxies, all located within a projected radius of 200 kpc and with a line-of-sight velocity of ±300 km s−1. We checked photometric and imaging data and found that these 14 dwarf galaxy groups are solitary, with no neighboring massive galaxies with M*>1010 M⊙ within 500 kpc and within ±1200 km s−1. These dwarf galaxies are gravitationally bound within halos with a dynamical mass of around Mdyn ∼ 1012 M⊙ and a virial radius of less than 400 kpc. The stellar mass fractions of these dwarf galaxy groups with Mdyn>1012 M⊙ are one magnitude lower than predicted by the canonical stellar mass and halo mass relation. These dwarf galaxy groups, therefore, are indications of dark matter halos in the local Universe that host only a few newly formed dwarf galaxies.
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BibTeX
@misc{yuan2026solitary,
title = {{Solitary dwarf galaxy groups as tracers of dark matter halos in the local Universe}},
author = {Z. S. Yuan and Z. L. Wen and J. L. Han},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2606.19193},
eprint = {2606.19193},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.19193},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Solitary dwarf galaxy groups as tracers of dark matter halos in the local Universe
AU - Z. S. Yuan
AU - Z. L. Wen
AU - J. L. Han
PY - 2026
DA - 2026/08/30
PB - arXiv
DO - 10.48550/arxiv.2606.19193
UR - https://arxiv.org/abs/2606.19193
AB - In ΛCDM cosmology, galaxies and clusters form within dark matter halos and merge in the hierarchical assembly paradigm to form massive systems. Using the released optical survey data, we searched for groups composed solely of dwarf galaxies, each with a stellar mass M_*<10^9.5 M_⊙. We identified 14 dwarf galaxy groups with at least 5 dwarf galaxies, all located within a projected radius of 200 kpc and with a line-of-sight velocity of ±300 km s^−1. We checked photometric and imaging data and found that these 14 dwarf galaxy groups are solitary, with no neighboring massive galaxies with M_*>10^10 M_⊙ within 500 kpc and within ±1200 km s^−1. These dwarf galaxies are gravitationally bound within halos with a dynamical mass of around M_dyn ∼ 10^12 M_⊙ and a virial radius of less than 400 kpc. The stellar mass fractions of these dwarf galaxy groups with M_dyn>10^12 M_⊙ are one magnitude lower than predicted by the canonical stellar mass and halo mass relation. These dwarf galaxy groups, therefore, are indications of dark matter halos in the local Universe that host only a few newly formed dwarf galaxies.
ER -