Related papers: Do AGN suppress star formation in early-type galax…
We present a general picture of the ongoing formation and evolution of early-type galaxies via a specific evolutionary sequence starting in the blue cloud and ending in the low-mass end of the red sequence. This evolutionary sequence…
The growth of supermassive black holes and their host galaxies are thought to be linked, but the precise nature of this symbiotic relationship is still poorly understood. Both observations and simulations of galaxy formation suggest that…
We present an analysis of 109 moderate-luminosity (41.9 < Log L{0.5-8.0 keV} < 43.7) AGN in the Extended Chandra Deep Field-South survey, which is drawn from 5,549 galaxies from the COMBO-17 and GEMS surveys having 0.4 < z < 1.1. These…
We use data from the Sloan Digital Sky Survey and visual classifications of morphology from the Galaxy Zoo project to study black hole growth in the nearby Universe (z < 0.05) and to break down the AGN host galaxy population by color,…
Feedback, in particular from active galactic nuclei (AGN), is believed to play a crucial role in the evolution of galaxies. In the local Universe, many galaxies with an AGN are indeed observed to reside in the so-called green valley,…
Models of galaxy formation invoke the major merger of gas-rich progenitor galaxies as the trigger for significant phases of black hole growth and the associated feedback that suppresses star formation to create red spheroidal remnants.…
The distribution of galaxies has been studied to show the difference between the blue cloud and red sequence and to define the green valley region. However, there are still many open questions regarding the importance of the green valley…
The coevolution between supermassive black holes (SMBHs) and their host galaxies has been proposed for more than a decade, albeit with little direct evidence about black hole accretion activities regulating galaxy star formation at $z>1$.…
We use SDSS+\textit{GALEX}+Galaxy Zoo data to study the quenching of star formation in low-redshift galaxies. We show that the green valley between the blue cloud of star-forming galaxies and the red sequence of quiescent galaxies in the…
We discuss the relationship between rest-frame color and optical luminosity for X-ray sources in the range 0.6<z<1.4 selected from the Chandra survey of the Extended Groth Strip (EGS). These objects are almost exclusively active galactic…
We explore the role of AGN in establishing and/or maintaining the bimodal colour distribution of galaxies by quenching their star-formation and hence, causing their transition from the blue to the red cloud. Important tests for this…
The old, red stars which constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone…
A major amendment in recent models of hierarchical galaxy formation is the inclusion of so-called AGN feedback. The energy input from an active central massive black hole is invoked to suppress star formation in early-type galaxies at later…
We study the properties of the host galaxies of Changing-Look Active Galactic Nuclei (CL AGNs) with the aim of understanding the conditions responsible for triggering CL activity. We find that CL AGN hosts primarily reside in the so-called…
We describe the effect of AGN light on host galaxy optical and UV-optical colours, as determined from X-ray-selected AGN host galaxies at z~1, and compare the AGN host galaxy colours to those of a control sample matched to the AGN sample in…
We explore the evolution with redshift of the rest-frame colours and space densities of AGN hosts (relative to normal galaxies) to shed light on the dominant mechanism that triggers accretion onto supermassive black holes as a function of…
Using new, highly accurate photometric redshifts from the MUSYC medium-band survey in the Extended Chandra Deep Field South (ECDF-S), we fit synthetic stellar population models to compare AGN host galaxies to inactive galaxies at 0.8 < z <…
We explore the question of whether low and moderate luminosity Active Galactic Nuclei (AGNs) are preferentially found in galaxies that are undergoing a transition from active star formation to quiescence. This notion has been suggested by…
We investigate the effect of environment on the presence and fuelling of Active Galactic Nuclei (AGN) by identifying galaxies hosting AGN in massive galaxy clusters and the fields around them. We have identified AGN candidates via optical…
We examine the relationship between galaxies, supermassive black holes and AGN using a sample of 22,000 narrow-emission-line AGN drawn from a a sample of 122,000 galaxies from the Sloan Digital Sky Survey. We have studied how AGN host…