arXiv subjects

C. Artale

Publications and source records attributed to C. Artale.

3 recordsLinked to original sources

arXiv2026

The new era of Lyman alpha emitters (LAEs): Typical star formation histories of LAEs in the ILLUSTRIS simulation

This work seeks to understand the nature of Lyman-alpha emitting galaxies in a cosmological context by analyzing their star-formation histories in the IllustrisTNG100 simulation, applying a recent selection criterion. The sample at z = 2.0 includes 6051 Lyman-alpha emitters, classified into four classes (35%, 33%, 21%, and 11%) using KMeans, an unsupervised machine-learning clustering method. The first class reproduces the typical star-formation history, characterized by the most intense star formation at the time of observation. The remaining classes exhibit atypical star-formation histories, with bursts occurring 0.3, 0.7, and 1.3 Gyr before the time of observation. The first class corresponds to galaxies with lower mass, Lyman-alpha luminosity, and total star-formation rate. We conclude that the classical definition of Lyman-alpha emitting galaxies-low mass, low dust content, and a single dominant burst-remains the most representative population (35% of the total sample), although other classes account for the remaining 65% of the cosmological sample.

astro-ph.GA↗

arXiv2026

The new era of Lyman alpha emitters (LAEs): Efficiency in the selection criteria

The ODIN survey has detected thousands of Lyman-alpha emitting galaxies across seven sky fields, covering nearly one hundred square degrees. One of these regions is the SHELA field, observed with DECam on the Blanco Telescope, reaching depths of approximately 25.3 AB mag in the N501 and N419 narrowbands and approximately 26.3 AB mag in the g and r broadbands over fifteen square degrees. In this work, we analyze the efficiency of the dual-continuum selection criterion as a function of broadband depth. Applied to the N501/N419 observations, we find that when the broadband data are roughly one magnitude deeper than the narrowband, nearly 80% of the LAEs are recovered, compared to only approximately 20% when both reach the same depth. This result shows that, for a fixed observing budget, the optimal strategy is to obtain broadband images approximately one magnitude deeper than the narrowband, since deeper exposures yield progressively smaller gains in the recovery fraction.

astro-ph.GA↗

arXiv2021

Baryons Shaping Dark Matter Haloes

In this work we aim at investigating the effects of baryons on the dark matter (DM) haloes structure, focusing on the correlation between the presence and importance of stellar discs and the halo shapes. We study the properties of a subsample of DM haloes from Fenix and EAGLE cosmological simulations. We inspect the central regions of haloes in the mass range [10.9 - 992.3] x 10^{10} Msun at z=0, comparing the hydrodynamic runs and their dark matter only (DMo) counterparts. Our results indicate that baryons have a significant impact on the shape of the inner halo, mainly within ~ 20 percent of the virial radius. We find haloes to be more spherical when hosting baryons. While the impact of baryons depends on the mass of the haloes, we also find a trend with morphology which suggests that the way baryons are assembled is also relevant in agreement with previous works. Our findings also indicate that disc galaxies preferentially form in haloes whose DMo counterparts were originally more spherical and with stronger velocity anisotropy. The presence of baryons alter the orbital structure of the DM particles of the haloes, which show a decrease in their velocity anisotropy, towards more tangentially biased orbits. This relative decrease is weaker in the case of disc-dominated galaxies. Our results point out to a cosmological connection between the final morphology of galaxies and the intrinsic properties of their DM haloes, which gets reinforce by the growth of the discs.

astro-ph.GA↗