A Morphological Study on Galaxies Hosting Optical Variability-Selected AGNs in the COSMOS Field

Abstract

The morphological study is crucial to investigate the connections between active galactic nuclei (AGN) activities and the evolution of galaxies. Substantial studies have found that radiative-mode AGNs primarily reside in disk galaxies, questioning the merger-driven mechanism of AGN activities. In this study, through S{é}rsic profile fitting and non-parametric morphological parameter measurements, we investigated the morphology of host galaxies of 485 optical variability-selected low luminosity AGNs at $z\lesssim 4.26$ in the COSMOS field. We analyzed high-resolution images of the Hubble Space Telescope to measure these morphological parameters. We only successfully measured the morphological parameters for 76 objects and most AGN hosts ($\sim 70\%$) were visually compact point-like sources. We examined the obtained morphological information as a function of redshift and compared them with literature data. We found that these AGN host galaxies showed no clear morphological preference. However, the merger rate increased with the higher hosts' SFRs and AGN luminosity. Interestingly, we found ongoing star formation consistent with the typical star forming populations in both elliptical and spiral galaxies while these two types of galaxies were more symmetric than normal star forming galaxies. These results suggested that optical variability-selected AGNs have} higher probabilities to reside in elliptical galaxies than infrared-selected AGNs (IR-AGNs), whose host galaxies had a strong disk-dominance, and supported recent studies that the AGN feedback could enhance star forming activities in host galaxies.

Accepted for publication in ApJ

References in corpus (18)

• The Cosmic Evolution Survey (COSMOS) -- Overview
• The Co-Evolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe
• UltraVISTA: a new ultra-deep near-infrared survey in COSMOS
• Galaxy Zoo 1 : Data Release of Morphological Classifications for nearly 900,000 galaxies
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• The Evolution of Galaxy Structure over Cosmic Time
• The bulk of the black hole growth since z~1 occurs in a secular universe: No major merger-AGN connection
• The Cosmic Evolution Survey (COSMOS): Subaru Observations of the HST COSMOS Field
• Bulge Formation by the Coalescence of Giant Clumps in Primordial Disk Galaxies
• X-CIGALE: fitting AGN/galaxy SEDs from X-ray to infrared
• Constraining the properties of AGN host galaxies with Spectral Energy Distribution modeling
• The effects of environment on morphological evolution between 0<z<1.2 in the COSMOS Survey
• AEGIS: Host Galaxy Morphologies of X-ray and Infrared-selected AGN at 0.2 < z < 1.2
• Virial Black Hole Mass Estimates for 280,000 AGNs from the SDSS Broad-Band Photometry and Single Epoch Spectra
• Infrared Selection of Obscured Active Galactic Nuclei in the COSMOS Field
• The Sizes of Quasar Host Galaxies with the Hyper Suprime-Cam Subaru Strategic Program
• Properties of AGN Multiband Optical Variability in the HSC SSP Transient Survey
• The AGN contribution to the UV-FIR luminosities of interacting galaxies and its role in identifying the Main Sequence

Cited by in corpus (1)

• Evidence for non-merger co-evolution of galaxies and their supermassive black holes