Small and Complex. I. The Three-component Structure of z ∼ 0 Massive Compact Quiescent Galaxies
4 affiliations
- 1Universidade Federal do Rio Grande do Sul
- 2European Southern Observatory
- 3Universidade Federal da Fronteira Sul
- 4Instituto de Matemática, Estatística e Física
Abstract
We investigate the morphology and structural properties of 246 massive compact quiescent galaxies (MCGs; log M ⋆ ∼ 10 –11, σ e ∼ 150–350 km s ⁻¹ , R e ∼ 0.7–2.5 kpc) at z ∼ 0, selected as outliers in the stellar mass–velocity dispersion and velocity dispersion–size relations, using g -, r -, and i -band Hyper Suprime-Cam images. We compare them to a control sample of average-sized quiescent galaxies (CSGs) matched in stellar mass, star formation rate, redshift, and g − i color. Both samples are dominated by S0 galaxies, comprising 93% of MCGs and 71% of CSGs, while ellipticals account for 4% and 11%, respectively. The fraction of interacting or morphologically disturbed systems is low in both samples (13% for MCGs and 16% for CSGs). Multicomponent decompositions of the g - and r -band images show that 75% of MCGs require a three-component model (bulge, disk, and envelope), while 21% are best fit by two components and 4% by a single Sérsic profile. Two-component MCGs are preferentially low-inclination systems, suggesting that the three-component fraction represents a lower limit. In contrast, only 7% of CSGs exhibit a comparable three-component structure. Bars are present in 29% of CSGs but are absent in MCGs. For three-component systems, MCGs and CSGs have similar bulge ( R e = 0.39 versus 0.45 kpc) and envelope ( R e = 6.4 versus 5.8 kpc) sizes, while MCG disks are significantly more compact ( R e = 1.9 versus 3.3 kpc). The envelope component shows a broad ellipticity distribution ( ϵ Envelope ∼ 0.0–0.6), which we interpret as corresponding to either a stellar halo or a thick disk.
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BibTeX
@article{clerici2026small,
title = {{Small and Complex. I. The Three-component Structure of z ∼ 0 Massive Compact Quiescent Galaxies}},
author = {Katia Slodkowski Clerici and Allan Schnorr-Müller and Ana Carolina Santiago-Menezes and Marina Trevisan and Tiago Vecchi Ricci and Rafael Merib-Dias and Felícia Palacios and Weslley Linck Becker and Fabricio Ferrari},
journal = {The Astrophysical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-4357/ae9e25},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/ae9e25},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Small and Complex. I. The Three-component Structure of z ∼ 0 Massive Compact Quiescent Galaxies
AU - Katia Slodkowski Clerici
AU - Allan Schnorr-Müller
AU - Ana Carolina Santiago-Menezes
AU - Marina Trevisan
AU - Tiago Vecchi Ricci
AU - Rafael Merib-Dias
AU - Felícia Palacios
AU - Weslley Linck Becker
AU - Fabricio Ferrari
PY - 2026
DA - 2026/10/05
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/ae9e25
UR - https://iopscience.iop.org/article/10.3847/1538-4357/ae9e25
AB - We investigate the morphology and structural properties of 246 massive compact quiescent galaxies (MCGs; log M ⋆ ∼ 10 –11, σ e ∼ 150–350 km s ⁻¹ , R e ∼ 0.7–2.5 kpc) at z ∼ 0, selected as outliers in the stellar mass–velocity dispersion and velocity dispersion–size relations, using g -, r -, and i -band Hyper Suprime-Cam images. We compare them to a control sample of average-sized quiescent galaxies (CSGs) matched in stellar mass, star formation rate, redshift, and g − i color. Both samples are dominated by S0 galaxies, comprising 93% of MCGs and 71% of CSGs, while ellipticals account for 4% and 11%, respectively. The fraction of interacting or morphologically disturbed systems is low in both samples (13% for MCGs and 16% for CSGs). Multicomponent decompositions of the g - and r -band images show that 75% of MCGs require a three-component model (bulge, disk, and envelope), while 21% are best fit by two components and 4% by a single Sérsic profile. Two-component MCGs are preferentially low-inclination systems, suggesting that the three-component fraction represents a lower limit. In contrast, only 7% of CSGs exhibit a comparable three-component structure. Bars are present in 29% of CSGs but are absent in MCGs. For three-component systems, MCGs and CSGs have similar bulge ( R e = 0.39 versus 0.45 kpc) and envelope ( R e = 6.4 versus 5.8 kpc) sizes, while MCG disks are significantly more compact ( R e = 1.9 versus 3.3 kpc). The envelope component shows a broad ellipticity distribution ( ϵ Envelope ∼ 0.0–0.6), which we interpret as corresponding to either a stellar halo or a thick disk.
SN - 0004-637X
SN - 1538-4357
ER -