The puzzling origin of massive compact galaxies in MaNGA

• Autor(a) principal: Müller, Allan Schnorr
• Data de Publicação: 2021
• Outros Autores: Trevisan, Marina, Riffel, Rogério, Chies-Santos, Ana Leonor, Furlanetto, Cristina, Ricci, Tiago Vecchi, Lohmann, Felipe Schmidt, Freitas, Rodrigo Flores de, Mallmann, Nícolas Dullius, Alamo-Martínez, Karla A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/235089
• topic: Evolucao galatica; Galaxias elipticas; Galaxias lenticulares; Cinemática; Galaxies : Elliptical and lenticular, cD; Galaxies : Evolution; Galaxies : Kinematics and dynamics; Galaxies : Statistics; Galaxies : Stellar content

We characterized the kinematics, morphology, and stellar population (SP) properties of a sample of massive compact quiescent galaxies (MCGs, 10 log M /M 11 and re ∼ 1–3 kpc) in the MaNGA Survey, with the goal of constraining their formation, assembly history, and assessing their relation with non-compact quiescent galaxies. We compared their properties with those of a control sample of median-sized quiescent galaxies (re ∼ 4–8 kpc) with similar effective velocity dispersions. MCGs have elevated rotational support, as evidenced by a strong anticorrelation between the Gauss–Hermite moment h3 and V/σ. In contrast, 30 per cent of control sample galaxies (CSGs) are slow rotators, and fast-rotating CSGs generally show a weak h3–V/σ anticorrelation. MCGs and CSGs have similar ages, but MCGs are more metal-rich and α-enhanced. Both MCGs and CSGs have shallow negative metallicity gradients and flat [α/Fe] gradients. On average, MCGs and CSGs have flat age gradients, but CSGs have a significantly larger dispersion of gradient values. The kinematics and SP properties of MCGs suggest that they experienced highly dissipative gas-rich events, such as mergers, followed by an intense, short, and centrally concentrated burst of star formation, between 4 and 10 Gyr ago (z ∼ 0.4–2), and had a quiet accretion history since then. This sequence of events might be analogous to, although less extreme than, the compaction events that formed compact quiescent galaxies at z ∼ 2. The small sizes of MCGs, and the high efficiency and short duration of their last star formation episode suggest that they are descendants of compact post-starburst galaxies.