Evolution of the galaxy merger fraction in the CLAUDS+HSC-SSP deep fields

Abstract

We estimate the evolution of the galaxy-galaxy merger fraction for $M_{\star }>10^{10.5}{M}_{\odot }$ galaxies over $0.25<z<1$ in the $\sim$18.6 deg${}^2$ deep CLAUDS+HSC-SSP surveys. We do this by training a Random Forest Classifier to identify merger candidates from a host of parametric morphological features, and then visually follow-up likely merger candidates to reach a high-purity, high-completeness merger sample. Correcting for redshift-dependent detection bias, we find that the merger fraction at $z=0$ is 1.0$\pm$0.2%, that the merger fraction evolves as $(1+z{)}^{2.3\pm 0.4}$, and that a typical massive galaxy has undergone $\sim$0.3 major mergers since $z=1$. This pilot study illustrates the power of very deep ground-based imaging surveys combined with machine learning to detect and study mergers through the presence of faint, low surface brightness merger features out to at least $z\sim 1$.

To appear in RNAAS

References in corpus (4)

• The Evolution of Galaxy Structure over Cosmic Time
• The Structures of Distant Galaxies I: Galaxy Structures and the Merger Rate to z~3 in the Hubble Ultra-Deep Field
• Galaxy Interactions Trigger Rapid Black Hole Growth: an unprecedented view from the Hyper Suprime-Cam Survey
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Cited by in corpus (3)

• Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• The Relation between Morphological Asymmetry and Nuclear Activity in Low-redshift Galaxies
• SDSS-IV MaNGA: The Incidence of Major Mergers in type I and II AGN Host Galaxies in the DR15 sample