Related papers: AGN in overdense environments at high-$z$ with AXI…
We combine deep X-ray survey data from the Chandra observatory and the wide-area/shallow XMM-XXL field to estimate the AGN X-ray luminosity function in the redshift range z=3-5. The sample consists of nearly 340 sources with either…
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…
The impact of feedback from Active Galactic Nuclei (AGN) on the cosmological evolution of the large scale structure is a long studied problem. However, it is still not well understood how the feedback energy couples to the ambient medium to…
The quenching of star formation is a crucial phase in galaxy evolution. Although active galactic nuclei (AGN) feedback has been proposed as a key driver of this transition, the lack of strong AGN in nearby quenching galaxies raises…
Dense gas in the centre of galaxies feeds massive black holes, but can also become a source of obscuration and limit our ability to find faint Active Galactic Nuclei (AGN). We use a high resolution cosmological radiative hydrodynamics…
We use deep follow-up XMM-Newton observations of 6 clusters discovered in the XXL Survey at $z>1$ to gain robust measurements of their X-ray properties and to investigate the extent to which scaling relations at low redshift are valid at…
We examine whether galaxy environments directly affect triggering nuclear activity in Sloan Digital Sky Survey (SDSS) local spiral galaxies using a volume-limited sample with the $r$-band absolute magnitude $M_{r} < -19.0$ and $0.02 < z <…
We have analyzed the clustering of ~ 90,000 narrow-line AGN drawn from the Data Release 4 (DR4) of the SDSS. We compute the cross-correlation between AGN and a reference sample of galaxies, and compare this to results for control samples of…
We use photometric redshifts derived from new $u$-band through 4.5$\mu$m Spitzer IRAC photometry in the 4.8\,deg$^2$ of the XMM-LSS field to construct surface density maps in the redshift range 0.1-1.5. Our density maps show evidence for…
We investigate the local and line-of-sight overdensities of strong gravitational lens galaxies using wide-area multiband imaging from the Hyper Suprime-Cam Subaru Strategic Program. We present 41 new definite or probable lens candidates…
To understand structure formation in the universe and impose stronger constraints on the cluster mass function and cosmological models, it is important to have large galaxy cluster catalogs. The Swift AGN and Cluster Survey is a…
Protoclusters at $z>2$ are gas-rich regions characterized by high star-formation activity. The same physical properties that enhance star formation in protoclusters are also thought to boost the growth of SMBHs. We aim to test this scenario…
We present a study of Spitzer/IRAC and X-ray active galactic nuclei (AGNs) selection techniques in order to quantify the overlap, uniqueness, contamination, and completeness of each. We investigate how the overlap and possible contamination…
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 examine the contribution of high-redshift (z>6) active galactic nuclei (AGNs) to cosmic hydrogen reionization, by tracing the growth and ionizing output of the first generation of supermassive black holes (SMBHs). Our calculations are…
We study the spatial clustering of 538 X-ray selected AGN in the 2 deg^2 XMM-COSMOS field that are spectroscopically identified to I_{AB}<23 and span the redshift range z=0.2-3.0. The median redshift and luminosity of the sample are z =…
Fast and energetic winds are invoked by galaxy formation models as essential processes in the evolution of galaxies. These outflows can be powered either by star-formation and/or AGN activity, but the relative dominance of the two…
We investigate the effect of AGN feedback associated to the bright QSO phase onto the color distribution of galaxies from z=0 up to z=4. To this aim, we insert a blast-wave model of AGN feedback in our semi-analytic model of galaxy…
We present a sample of $i_{775}$-dropout candidates identified in five Hubble Advanced Camera for Surveys fields centered on Sloan Digital Sky Survey QSOs at redshift $z\sim 6$. Our fields are as deep as the Great Observatory Origins Deep…
We combine results from deep ALMA observations of massive ($M_*>10^{10}\;M_{\odot}$) galaxies at different redshifts to show that the column density of their inter stellar medium (ISM) rapidly increases towards early cosmic epochs. Our…