Understanding galaxies and the origin of the golden mass through the study of scaling relations across cosmic history
Abstract
The total mass distribution in galaxies strongly influences star formation (SF), both directly via gas availability and feedback, and indirectly via the dark matter (DM) potential well. Star formation efficiency peaks at a characteristic stellar mass of 5 × 1010 M⊙, often termed the "golden mass", where feedback mechanisms minimally affect SF. This scale also appears in other scaling relations: correlations between stellar population gradients, DM fraction, and total mass density slope versus stellar mass all show pronounced minima at the golden mass. How, why, and when does this golden mass emerge during galaxy evolution? Early cosmic epochs (z > 1.5) remain largely unexplored, yet they probe the formative stages of galaxy mass assembly. They provide the full redshift baseline needed to constrain the buildup of stellar mass and the efficiency of gas-to-star conversion. By combining high resolution, multiplexing, and a wide field of view, SHARP on the ELT will address these questions, delivering sharper and deeper data than JWST. In this SHARP White Paper contribution, we present a scientific case exploiting these unique characteristics. SHARP will enable precise measurements of stellar population gradients, DM fractions, and total mass density slopes. Using the mIFU mode, SHARP will obtain spatially-resolved stellar population and dynamical maps for galaxies at z > 1.5. Reconstructing these observables for early- and late-type systems will allow us to trace the emergence of the golden mass across cosmic time, and to decode the impact of galaxy processes (mergers, SN, and AGN feedback) by comparing observations with cosmological simulations. (abridged)
Related
- From Scaling Relations to Physical Laws: Constraining the Physics of Star Formation Across Local Galaxies
- Inflow-driven galaxy evolution - II: A hierarchy in the scaling relations of star-forming galaxies
- Euclid. Predicting scaling relations for emission-line galaxies using simulated data
- Evolution of the morphology-density and morphology-mass relations of quiescent galaxies at 0.5 {2}lt;z<$ 2.5 in the COSMOS-Web survey
- Link between the properties of circumgalactic outflows and the recent star formation history of their host galaxies
BibTeX
@misc{tortora2026understanding,
title = {{Understanding galaxies and the origin of the golden mass through the study of scaling relations across cosmic history}},
author = {C. Tortora and A. Gallazzi and A. Gargiulo and F. La Barbera and N. R. Napolitano and R. Ragusa and S. Zibetti},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.06333},
eprint = {2611.06333},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.06333},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Understanding galaxies and the origin of the golden mass through the study of scaling relations across cosmic history
AU - C. Tortora
AU - A. Gallazzi
AU - A. Gargiulo
AU - F. La Barbera
AU - N. R. Napolitano
AU - R. Ragusa
AU - S. Zibetti
PY - 2026
DA - 2026/11/04
PB - arXiv
DO - 10.48550/arxiv.2611.06333
UR - https://arxiv.org/abs/2611.06333
AB - The total mass distribution in galaxies strongly influences star formation (SF), both directly via gas availability and feedback, and indirectly via the dark matter (DM) potential well. Star formation efficiency peaks at a characteristic stellar mass of 5 × 10^10 M_⊙, often termed the "golden mass", where feedback mechanisms minimally affect SF. This scale also appears in other scaling relations: correlations between stellar population gradients, DM fraction, and total mass density slope versus stellar mass all show pronounced minima at the golden mass. How, why, and when does this golden mass emerge during galaxy evolution? Early cosmic epochs (z > 1.5) remain largely unexplored, yet they probe the formative stages of galaxy mass assembly. They provide the full redshift baseline needed to constrain the buildup of stellar mass and the efficiency of gas-to-star conversion. By combining high resolution, multiplexing, and a wide field of view, SHARP on the ELT will address these questions, delivering sharper and deeper data than JWST. In this SHARP White Paper contribution, we present a scientific case exploiting these unique characteristics. SHARP will enable precise measurements of stellar population gradients, DM fractions, and total mass density slopes. Using the mIFU mode, SHARP will obtain spatially-resolved stellar population and dynamical maps for galaxies at z > 1.5. Reconstructing these observables for early- and late-type systems will allow us to trace the emergence of the golden mass across cosmic time, and to decode the impact of galaxy processes (mergers, SN, and AGN feedback) by comparing observations with cosmological simulations. (abridged)
ER -