Related papers: Are galaxies with AGN a transition population?
As a natural consequence of galaxy mergers, binary active galactic nuclei (AGNs) should be commonplace. Nevertheless, observational confirmations are rare, especially for binaries with separations less than ten kpc. Such a system may show…
Active galactic nuclei (AGNs) are the compact, energetic central regions of galaxies, powered by supermassive black holes that accrete surrounding gas and dust. Their optical spectra can be identified by strong emission-line signatures…
SHARDS is an ongoing ESO/GTC large program that is obtaining ultra-deep photometry of the GOODS-North field in 24 medium-band filters (reaching m=26.5 AB in all bands) in the 500-950 nm range with GTC/OSIRIS. It is designed to study the…
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,…
We present a study of the host galaxies of AGN selected from the zCOSMOS survey to establish if accretion onto supermassive black holes and star formation are explicitly linked up to z~1. We identify 152 galaxies that harbor AGN, based on…
We study a combined sample of 264 star-forming, 51 composite, and 73 active galaxies using optical spectra from SDSS and mid-infrared (mid-IR) spectra from the Spitzer Infrared Spectrograph. We examine optical and mid-IR spectroscopic…
It is still a matter of debate whether the properties of galaxies hosting an Active Galactic Nucleus (AGN) are different from the properties of quiescent galaxies. We constructed a sample of ~50 AGN at a mean redshift of <z>~0.6 that lack a…
Many X-ray bright active galactic nuclei (AGN) are predicted to follow an extended stage of obscured black hole growth. In support of this picture we examine the X-ray undetected AGNs in the COSMOS field and compare their host galaxies with…
Active galactic nucleus (AGN) growth in disk-dominated, merger-free galaxies is poorly understood, largely due to the difficulty in disentangling the AGN emission from that of the host galaxy. By carefully separating this emission, we…
We determine the intrinsic shapes and orientations of 27,450 type I and II active galactic nucleus (AGN) galaxies in the spectroscopic sample of the SDSS DR7, by studying the distribution of projected axis ratios of AGN hosts. Our aim is to…
We explore how the local environment is related to the redshift, type, and luminosity of active galactic nuclei (AGN). Recent simulations and observations are converging on the view that the extreme luminosity of quasars is fueled in major…
We analyze a volume-limited sample from the Sloan Digital Sky Survey (SDSS) to compare the spatial clustering and physical properties of active galactic nuclei (AGN) and star-forming galaxies (SFG) at fixed stellar mass. We find no…
We visually and quantitatively determine the host galaxy morphologies of 94 intermediate redshift (0.2 < z < 1.2) active galactic nuclei (AGN), selected using Chandra X-ray and Spitzer mid-infrared data in the Extended Groth Strip. Using…
We present and discuss optical imaging of 76 AGN which represent the 2MASS-selected sample for z<0.3, from a full list of 243. They are found to have dust-obscured nuclei, residing in host galaxies that show a high fraction (>70%) of tidal…
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…
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…
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…
Using a large sample of local galaxies (144,940) with -17.5< Mr <-22 and 0.025< z <0.107, selected from SDSS DR5, we compare AGN host galaxies with non-AGN galaxies at matched luminosity, velocity dispersion, color, color gradient, or…
Using low-redshift (z<0.09) samples of AGNs, normal galaxies and groups of galaxies selected from the Sloan Digital Sky Survey (SDSS), we study the environments of type 1 and type 2 AGNs both on small and large scales. Comparisons are made…
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…