54 citations · 153 across the 15 of their papers we have counts for
16 papers
The rise and decline of a transient obscuration event in a moderately distant type-I quasar
A. Akylas, A. Georgakakis, E. Pouliasis +5
Outflows of ionised material, often dubbed warm absorbers (WAs), are common in nearby Seyferts but sparse in distant and more energetic quasars (QSOs). We present multi-epoch X-ray…
X-ray luminosity function of Compton-thick AGN in the early Universe (z > 3). Robustness and biases of the CTK population
Angel Ruiz, Ektoras Pouliasis, Ioannis Georgantopoulos
The population of Compton-thick (CTK) AGN represents a critical yet elusive phase in the growth of supermassive black holes. Constraining their abundance and evolution at high z is…
Harnessing the XMM-Newton data: X-ray spectral modelling of 4XMM-DR11 detections and 4XMM-DR11s sources
A. Viitanen, G. Mountrichas, H. Stiele +13
The XMM-Newton X-ray observatory has played a prominent role in astrophysics, conducting precise and thorough observations of the X-ray sky for the past two decades. The most recen…
The incidence of X-ray AGN and non-AGN galaxies in the far-infrared: insights into host galaxy properties and AGN obscuration
G. Mountrichas, F. J. Carrera, I. Georgantopoulos +3
We investigate the far-infrared (far-IR) incidence of X-ray-selected active galactic nuclei (AGN) and non-AGN galaxies as a function of stellar mass (M), star formation rate (S…
XXL-HSC: Host properties of X-ray detected AGNs in XXL clusters
E. Drigga, E. Koulouridis, E. Pouliasis +10
There is compelling evidence that AGNs are strongly influenced by their environment. Therefore, studying the AGN population of clusters is essential, as both large-scale structures…
Identification of high-redshift X-ray active galactic nuclei in the 4XMM-DR11 serendipitous catalogue using DES data: Comparative analysis with optically-selected QSOs
E. Pouliasis, A. Ruiz, I. Georgantopoulos +8
X-rays provide a robust method in identifying AGN. However, in the high-redshift Universe, their space density is relatively low, and, in combination with the small areas covered b…
The Compton-thick AGN luminosity function in the local Universe: A robust estimate combining BAT detections and NuSTAR spectra
I. Georgantopoulos, E. Pouliasis, A. Ruiz +1
The Compton-thick Active Galactic Nuclei (AGN) arguably constitute the most elusive class of sources as they are absorbed by large column densities above logN_H(cm^-2)=24. These ex…
AGN populations in the local universe: their alignment with the main-sequence, characteristics of their stellar populations, accretion efficiency, and the impact of AGN feedback
G. Mountrichas, A. Ruiz, I. Georgantopoulos +3
In this study, we utilize a sample of 338 galaxies within the redshift range of , drawn from the Sloan Digital Sky Survey (SDSS), for which there are available clas…
Observational Properties of AGN Obscuration During the Peak of Accretion Growth
Bovornpratch Vijarnwannaluk, Masayuki Akiyama, Malte Schramm +11
We investigated the gas obscuration and host galaxy properties of active galactic nuclei (AGN) during the peak of cosmic accretion growth of supermassive black holes (SMBHs) at red…
AGN X-ray luminosity function and absorption function in the Early Universe ()
E. Pouliasis, A. Ruiz, I. Georgantopoulos +15
The XLF of AGN offers a robust tool to study the evolution and the growth of SMBHs over cosmic time. Owing to the limited area probed by X-ray surveys, optical surveys are routinel…
Ensemble X-ray variability of optically selected QSOs: dependence on black hole mass and Eddington ratio
A. Georgakakis, J. Buchner, A. Ruiz +7
Although flux variability is one of the defining properties of accretion flows onto supermassive black holes, its dependence on physical parameters such as the mass of the compact…
The link among X-ray spectral properties, AGN structure and the host galaxy
G. Mountrichas, A. Viitanen, F. J. Carrera +5
In this work, we compare the SMBH and host galaxy properties of X-ray obscured and unobscured AGN. For that purpose, we use X-ray detected AGN in the 4XMM-DR11 catalo…
The STATiX pipeline for the detection of X-ray transients in three dimensions
A. Ruiz, A. Georgakakis, I. Georgantopoulos +3
The recent serendipitous discovery of a new population of short duration X-ray transients, thought to be associated with collisions of compact objects or stellar explosions in dist…
An obscured AGN population hidden in the VIPERS galaxies: identification through spectral energy distribution decomposition
E. Pouliasis, G. Mountrichas, I. Georgantopoulos +3
The detection of X-ray emission constitutes a reliable and efficient tool for the selection of Active Galactic Nuclei (AGNs), although it may be biased against the most heavily abs…
Obscuration properties of mid-IR selected AGN
G. Mountrichas, I. Georgantopoulos, A. Ruiz +1
The goal of this work is to study the obscuration properties of mid-infrared (mid-IR) selected AGN. For that purpose, we use {\it{WISE}} sources in the Stripe 82-XMM area to identi…
Disentangling the AGN and Star-Formation connection using XMM-Newton
V. A. Masoura, G. Mountrichas, I. Georgantopoulos +3
There is growing evidence supporting the coeval growth of galaxies and their resident SMBH. Most studies also claim a correlation between the activity of the SMBH and the star-form…