Merging history of massive galaxies at 3<z<6

Abstract

The observational data of high redshift galaxies become increasingly abundant, especially since the operation of the James Webb Space Telescope (JWST), which allows us to verify and optimize the galaxy formation model at high redshifts. In this work, we investigate the merging history of massive galaxies at $3<z<6$ using a well-developed semi-analytic galaxy formation catalogue. We find that the major merger rate increases with redshift up to 3 and then flattens. The fraction of wet mergers, during which the sum of the cold gas mass is higher than the sum of the stellar mass in two merging galaxies, also increases from $\sim$ 34\% at $z=0$ to 96\% at $z=3$. Interestingly, almost all major mergers are wet at $z>3$ . This can be attributed to the high fraction ($>50\%$) of cold gas at $z>3$. In addition, we study some special systems of massive merging galaxies at $3<z<6$, including the massive gas-rich major merging systems and extreme dense proto-clusters, and investigate the supermassive black hole-dark matter halo mass relation and dual AGNs. We find that the galaxy formation model reproduces the incidence of those observed massive galaxies, but fails to reproduce the relation between the supermassive black hole mass and the dark matter halo mass at $z\sim 6$. The latter requires more careful estimates of the supermassive black hole masses observationally. Otherwise, it could suggest modifications of the modeling of the supermassive black hole growth at high redshifts.

9 pages,8figures

References in corpus (13)

• The hierarchical formation of the brightest cluster galaxies
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• Galaxy Merger Morphologies and Time-Scales from Simulations of Equal-Mass Gas-Rich Disc Mergers
• Galaxy pairs in the Sloan Digital Sky Survey - IX: Merger-induced AGN activity as traced by the Wide-field Infrared Survey Explorer
• Galaxy growth in a massive halo in the first billion years of cosmic history
• Galaxy growth in the concordance $\Lambda$CDM cosmology
• A chronicle of galaxy mass assembly in the EAGLE simulation
• Major Merging History in CANDELS. I. Evolution of the Incidence of Massive Galaxy-Galaxy Pairs from z=3 to z~0
• The MUSE Hubble Ultra Deep Field Survey. IX. Evolution of galaxy merger fraction since z~6
• The redshift evolution of major merger triggering of luminous AGN: a slight enhancement at z$\sim$2
• Merger induced clump formation in distant infrared luminous starburst galaxies
• The Illustris Simulation: Supermassive Black Hole - Galaxy Connection Beyond the Bulge
• Black versus Dark: Rapid Growth of Supermassive Black Holes in Dark Matter Halos at z ~ 6

Cited by in corpus (1)

• Evolved galaxies in high-density environments across $2.0\le z<4.2$ using the ZFOURGE survey