The redshift evolution of the S0 fraction for $z<1$ in COSMOS

Abstract

Lenticular (S0) galaxies are galaxies that exhibit a bulge and disk component, yet lack any clear spiral features. With features considered intermediary between spirals and ellipticals, S0s have been proposed to be a transitional morphology, however their exact origin and nature is still debated. In this work, we study the redshift evolution of the S0 fraction out to $z\sim 1$ using deep learning to classify F814W ($i$-band) HST-ACS images of 85,378 galaxies in the Cosmological Evolution Survey (COSMOS). We classify galaxies into four morphological categories: elliptical (E), S0, spiral (Sp), and irregular/miscellaneous (IrrM). Our deep learning models, initially trained to classify SDSS images with known morphologies, have been successfully adapted to classify high-redshift COSMOS images via transfer learning and data augmentation, enabling us to classify S0s with superior accuracy. We find that there is an increase in the fraction of S0 galaxies with decreasing redshift, along with a corresponding reduction in the fraction of spirals. We find a bimodality in the mass distribution of our classified S0s, from which we find two separate S0s populations: high-mass S0s, which are mostly red and quiescent; and low-mass S0s, which are generally bluer and include both passive and star-forming S0s, the latter of which cannot solely be explained via the faded spiral formation pathway. We also find that the S0 fraction in high-mass galaxies begins rising at higher $z$ than in low-mass galaxies, implying that high-mass S0s evolved earlier.

18 pages, 18 figures, accepted for publication in MNRAS

References in corpus (33)

• Batch Normalization: Accelerating Deep Network Training by Reducing Internal Covariate Shift
• Array Programming with NumPy
• The Cosmic Evolution Survey (COSMOS) -- Overview
• Rotation-invariant convolutional neural networks for galaxy morphology prediction
• The Evolution of Galaxy Structure over Cosmic Time
• COSMOS2020: A panchromatic view of the Universe to $z\sim 10$ from two complementary catalogs
• Weak Gravitational Lensing with COSMOS: Galaxy Selection and Shape Measurements
• A Wide-field Survey of Two Z~0.5 Galaxy Clusters: Identifying the Physical Processes Responsible for the Observed Transformation of Spirals into S0s
• Galaxy Zoo DECaLS: Detailed Visual Morphology Measurements from Volunteers and Deep Learning for 314,000 Galaxies
• Galaxy And Mass Assembly (GAMA): Galaxy close-pairs, mergers, and the future fate of stellar mass
• The Near-infrared S0 Survey III: Morphology of 15 Southern Early-type Disk Galaxies
• The Evolution of the Field and Cluster Morphology-Density Relation for Mass-Selected Samples of Galaxies
• Galaxy morphological classification in deep-wide surveys via unsupervised machine learning
• On the interdependence of galaxy morphology, star formation, and environment in massive galaxies in the nearby Universe
• The Origin of S0s in Clusters: evidence from the bulge and disc star formation histories
• Formation of S0 galaxies through mergers. Bulge-disc structural coupling resulting from major mergers
• Formation of S0 galaxies through mergers. V. Antitruncated stellar discs resulting from major mergers
• Morphological classification of galaxies with deep learning: comparing 3-way and 4-way CNNs
• Galaxy Morphology Network: A Convolutional Neural Network Used to Study Morphology and Quenching in $\sim 100,000$ SDSS and $\sim 20,000$ CANDELS Galaxies
• Formation of S0 galaxies through mergers. Evolution in the Tully-Fisher relation since $z\sim 1$
• The formation of S0 galaxies: evidence from globular clusters
• Pushing automated morphological classifications to their limits with the Dark Energy Survey
• The two formation pathways of S0 galaxies
• The SAMI Galaxy Survey: A Range in S0 Properties Indicating Multiple Formation Pathways
• The SLUGGS survey: Using extended stellar kinematics to disentangle the formation histories of low mass S0 galaxies
• Galaxy properties as revealed by MaNGA. III. Kinematic profiles and stellar population gradients in S0s
• The evolution of barred galaxies in the EAGLE simulations
• Galaxy Zoo: 3D -- Crowd-sourced Bar, Spiral and Foreground Star Masks for MaNGA Target Galaxies
• BUDDI-MaNGA II: The Star-Formation Histories of Bulges and Discs of S0s
• The local universe in the era of large surveys. I. Spectral classification of S0 galaxies
• Formation of S0s in extreme environments III: the role of environment in the formation pathways
• Connecting galaxy structure and star formation: the role of environment in formation of S0 galaxies
• The JWST Hubble Sequence: The Rest-Frame Optical Evolution of Galaxy Structure at $1.5<z<8$

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