Evidence for Quasar Activity Triggered by Galaxy Mergers in HST Observations of Dust-reddened Quasars

TL;DR: In this paper, the importance of galaxy-galaxy major mergers (1:4) in growing supermassive black holes (BHs) was investigated using mid-infrared observations in the WISE All-Sky survey.

Abstract: The question of whether galaxy mergers are linked to the triggering of active galactic nuclei (AGN) continues to be a topic of considerable debate. The issue can be broken down into two distinct questions: 1) Can galaxy mergers trigger AGN? 2) Are galaxy mergers the dominant AGN triggering mechanism? A complete picture of the AGN-merger connection requires that both of these questions are addressed with the same dataset. In previous work, we have shown that galaxy mergers selected from the Sloan Digital Sky Survey (SDSS) show an excess of both optically-selected, and mid-IR colour-selected AGN, demonstrating that the answer to the first of the above questions is affirmative. Here, we use the same optical and mid-IR AGN selection to address the second question, by quantifying the frequency of morphological disturbances in low surface brightness r-band images from the Canada France Imaging Survey (CFIS). Only ~30 per cent of optical AGN host galaxies are morphologically disturbed, indicating that recent interactions are not the dominant trigger. However, almost 60 per cent of mid-IR AGN hosts show signs of visual disturbance, indicating that interactions play a more significant role in nuclear feeding. Both mid-IR and optically selected AGN have interacting fractions that are a factor of two greater than a mass and redshift matched non-AGN control sample, an excess that increases with both AGN luminosity and host galaxy stellar mass.

TL;DR: In this paper, the importance of galaxy-galaxy major mergers (1:4) in growing supermassive black holes (BHs) was investigated using mid-infrared observations in the WISE All-Sky survey.

TL;DR: In this article, the authors examined the host morphologies of heavily obscured active galactic nuclei (AGN) at z = 1 to test whether obscured supermassive black hole growth at this epoch is preferentially linked to galaxy mergers.

TL;DR: In this article, the spectral evolution of stellar populations at ages between 100,000 yr and 20 Gyr at a resolution of 3 A across the whole wavelength range from 3200 to 9500 A for a wide range of metallicities.

TL;DR: The mass of supermassive black holes correlate almost perfectly with the velocity dispersions of their host bulges, Mbh ∝ σα, where α = 48 ± 05.

TL;DR: In this article, the authors constructed dynamical models for a sample of 36 nearby galaxies with Hubble Space Telescope (HST) photometry and ground-based kinematics, assuming that each galaxy is axisymmetric, with a two-integral distribution function, arbitrary inclination angle, a position-independent stellar mass-to-light ratio, and a central massive dark object of arbitrary mass M•.

TL;DR: The straw person model (SPM) as mentioned in this paper has been proposed to explain the orientation effects of active galactic nuclei (AGN) and quasars in the line of sight (LOS) images.