The effect of local and large scale environment on the star formation histories of galaxies

• Main Authors: Torres-Ríos, G, Pérez, I, Verley, S, Domínguez-Gómez, J, Argudo-Fernández, M, Puertas, S. Duarte, Jiménez, A, Ruiz-Lara, T, Zurita, A, Bidaran, B, Conrado, A, Espada, D, García-Benito, R, Delgado, R. M. González, Falcón-Barroso, J, Florido, E, Sánchez-Blázquez, P, Sánchez-Menguiano, L
• Format: Journal Article
• Language: English
• Published: 01-10-2024
• Subjects: Physics - Astrophysics of Galaxies
• DOI: 10.48550/arxiv.2410.00959

We aim to investigate how the local environment influences the star formation
history (SFH) of galaxies residing in various large-scale environments. We
categorise a sample of 9384 galaxies into the three primary large scale
structures (voids, walls \& filaments, and clusters) and further classify them
based on their local environment (as either "singlets" or group members),
through a search of companion galaxies within sky-projected distances $\Delta
r_p < 0.45$ Mpc and velocity differences $\Delta v < 160$ $\text{km s}^{-1}$.
Subsequently, we explore these subsamples through SFH data from previous works.
Throughout the study, galaxies are divided into long-timescale SFH galaxies
(LT-SFH), which assemble their mass steadily along cosmic time, and
short-timescale SFH galaxies (ST-SFH), which form their stars early. We then
compare characteristic mass assembly look-back times. The distributions of mass
assembly look-back times in ST-SFH galaxies are statistically different for
singlets and groups. These differences are only found in LT-SFH galaxies when
studying these distributions in stellar mass bins. Our results indicate that
the large-scale environment is related to a delay in mass assembly of up to
$\sim$2 Gyr, while this delay is $<$1 Gyr in the case of local environment. The
effect of both kinds of environment is more significant in less massive
galaxies, and in LT-SFHs. Our results are consistent with galaxies in groups
assembling their stellar mass earlier than singlets, especially in voids and
lower mass galaxies. Local environment plays a relevant role in stellar mass
assembly times, although we find that large-scale structures also cause a delay
in mass assembly, more so in the case of cluster galaxies.