Living near filaments: How environment shapes age profiles in low-mass galaxies
Abstract
U-shaped radial age profiles have recently been reported in low-mass galaxies. This type of profile differs from the usually observed positive radial age gradients of the low-mass regime. We aim to characterise the environment in which low-mass galaxies with U-shaped age profiles are more commonly found. We use the IllustrisTNG-50 hydrodynamical simulations to select a sample of galaxies with stellar masses ranging from 109 M⊙ to 1010 M⊙. Based on their radial age profiles, we classify the sample into galaxies with and without a U-shaped feature. We define a U-shaped profile as one where stellar ages decrease towards a local minimum and subsequently increase, requiring an age contrast of at least 0.4 Gyr on either side of the minimum relative to its value. We find 145 galaxies with U-shaped age profiles (∼ 11% of the sample). They are mostly central systems (∼ 72%) and ∼ 82% of them reside within low-mass halos (M200 < 1012 M⊙). We also find that galaxies exhibiting this feature are located at large distances from galaxy groups but close to cosmic filaments, with a median distance of ∼ 265 kpc, whereas those without U-shaped age profiles tend to be located farther away from these structures (∼ 351 kpc).
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BibTeX
@misc{tau2026living,
title = {{Living near filaments: How environment shapes age profiles in low-mass galaxies}},
author = {Elisa A. Tau and Diego Pallero and Rory Smith and Raúl Baier-Soto and Antonela Monachesi and Silvio Varela-Lavin},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.06632},
eprint = {2611.06632},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.06632},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Living near filaments: How environment shapes age profiles in low-mass galaxies
AU - Elisa A. Tau
AU - Diego Pallero
AU - Rory Smith
AU - Raúl Baier-Soto
AU - Antonela Monachesi
AU - Silvio Varela-Lavin
PY - 2026
DA - 2026/11/04
PB - arXiv
DO - 10.48550/arxiv.2611.06632
UR - https://arxiv.org/abs/2611.06632
AB - U-shaped radial age profiles have recently been reported in low-mass galaxies. This type of profile differs from the usually observed positive radial age gradients of the low-mass regime. We aim to characterise the environment in which low-mass galaxies with U-shaped age profiles are more commonly found. We use the IllustrisTNG-50 hydrodynamical simulations to select a sample of galaxies with stellar masses ranging from 10^9 M_⊙ to 10^10 M_⊙. Based on their radial age profiles, we classify the sample into galaxies with and without a U-shaped feature. We define a U-shaped profile as one where stellar ages decrease towards a local minimum and subsequently increase, requiring an age contrast of at least 0.4 Gyr on either side of the minimum relative to its value. We find 145 galaxies with U-shaped age profiles (∼ 11% of the sample). They are mostly central systems (∼ 72%) and ∼ 82% of them reside within low-mass halos (M_200 < 10^12 M_⊙). We also find that galaxies exhibiting this feature are located at large distances from galaxy groups but close to cosmic filaments, with a median distance of ∼ 265 kpc, whereas those without U-shaped age profiles tend to be located farther away from these structures (∼ 351 kpc).
ER -