MAGNUS I: A MUSE-DEEP sample of early-type galaxies at intermediate redshift

TL;DR

This study analyzes a sample of 212 early-type galaxies at intermediate redshift, revealing that their structural, kinematic, and stellar population properties are similar to local galaxies, indicating little evolution over the past 7 billion years.

Contribution

The paper provides a detailed analysis of early-type galaxies at $0.25<z<0.75$ using MUSE-DEEP and HST data, demonstrating the stability of their fundamental properties over time.

Findings

Slow rotator fraction is consistent with local samples.

Kinematic and photometric axes are generally aligned.

Stellar population properties correlate with velocity dispersion.

Abstract

We present a sample of 212 early-type galaxies (ETGs) at redshifts $0.25 < z < 0.75$. We combine deep integral-field spectroscopy from the MUSE-DEEP survey with high-resolution HST imaging to study the structure, kinematics, and stellar populations of these galaxies. We measure spatially resolved stellar kinematics and use the specific angular momentum proxy, $\lambda_R$, to classify galaxies into fast and slow rotators. We find a slow rotator fraction consistent with local Universe samples, suggesting little evolution in the massive ETG population since $z \sim 1$. The kinematic and photometric axes of fast rotators are generally well-aligned, similar to their local counterparts. We find that global stellar population properties, such as age, metallicity, and mass-to-light ratio ($M_*/L$), correlate strongly with the central velocity dispersion ($\sigma_\mathrm{e}$), following trends established for local ETGs. Slow rotators are typically more massive, have higher $\sigma_\mathrm{e}$, and are more metal-rich than fast rotators. Our findings indicate that the fundamental structural, kinematic, and stellar population scaling relations of massive ETGs were already in place by $z \sim 0.75$, suggesting their evolutionary pathways have remained stable over the last $\sim 7$ Gyr.