Evolution of submillimeter galaxies in cosmic web environments

Le résumé fourni par la source

Submillimeter galaxies (SMGs) are among the most intriguing and luminous objects in the high-redshift universe. These highly dusty star-forming systems provide valuable insights into galaxy formation and evolution and are likely affected by their cosmic environment. However, it is challenging to obtain large-area surveys with resolved SMGs and their spectroscopic redshifts. We quantify the environmental dependence of SMGs from z=4 to z=1 by assessing their preferential association with cosmic web structures (cluster-halo, filaments, and voids/walls) and evolution using the FLAMINGO simulation. We used the cosmic web finder DisPerSE to identify filamentary structures at redshifts z=4, 3, 2, 1.5, and 1 in the highest-resolution FLAMINGO simulation using galaxies with M_ * ≥ 10^ 9 as tracers of large-scale structure. We defined five cosmic environments (inner cluster-halo, outer cluster-halo, inner filament, outer filament, and void/wall) at each redshift considering mass evolution of cluster-halos and density evolution of filaments. The fraction of SMGs in the inner cluster-halo environment declines from sim30% at z=4 to sim3% by z=1, and similar trends are observed in other environments. The abundance of SMGs within a cluster-halo increases with halo mass and mirrors the increase in the total galaxy population. Consequently, the ratio of the SMG halo occupation to that of all galaxies is largely insensitive to halo mass, but varies with redshift. In contrast, the ratio of the halo occupation of non-SMGs to that of all galaxies declines with halo mass and shows little redshift evolution because star formation is suppressed in massive halos. We further show that SMGs tend to contribute less to the massive end of the stellar mass function in low-density environments, with central and satellite SMGs forming two distinct populations in the inner cluster-halos. SMGs occupy the metal-rich side of the star-forming gas metallicity distribution, but rarely attain the very highest metallicities because ongoing enrichment is limited by gas depletion. Interestingly, the brightest SMGs (S_ 850 > 10 mJy) are found exclusively in inner cluster-halos, highlighting a strong connection between SMG luminosity and environmental density. Our results show that SMGs dominate star formation in dense environments, contributing up to 80% of the star formation rate in inner cluster-halos at z=4, but less than 50% in low-density regions. Taken together, these results demonstrate that SMGs dominate the buildup of stellar mass and metals in dense environments, while their relative importance declines toward lower-redshift and lower-density regions.

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