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⋆ > 1010.5M⊙ galaxies over 0.25 < z < 1 in the ∼18.6 deg2 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% ± 0.2%, that the merger fraction evolves as (1 + z)2.3 ± 0.4, and that a typical massive galaxy has undergone ∼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 ∼ 1.
- Publication:
-
Research Notes of the American Astronomical Society
- Pub Date:
- June 2021
- DOI:
- 10.3847/2515-5172/ac0911
- arXiv:
- arXiv:2106.04266
- Bibcode:
- 2021RNAAS...5..144T
- Keywords:
-
- Galaxy mergers;
- Galaxy evolution;
- Galaxy interactions;
- 608;
- 594;
- 600;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- To appear in RNAAS