21 citations · 61 across the 14 of their papers we have counts for
15 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…
Towards a complete census of luminous Compton-thick Active Galactic Nuclei in the local Universe
A. Akylas, I. Georgantopoulos, P. Gandhi +2
X-ray surveys provide the most efficient means for the detection of Active Galactic Nuclei (AGN). However, they face difficulties in detecting the most heavily obscured Compton-thi…
STONKS: Quasi-real time XMM-Newton transient detection system
E. Quintin, N. A. Webb, I. Georgantopoulos +6
Over recent decades, astronomy has entered the era of massive data and real-time surveys. This is improving the study of transient objects - although they still contain some of the…
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…
The Hubble Catalog of Variables (HCV)
A. Z. Bonanos, M. Yang, K. V. Sokolovsky +33
The Hubble Space Telescope (HST) has obtained multi-epoch observations providing the opportunity for a comprehensive variability search aiming to uncover new variables. We have the…
The Hubble Catalog of Variables (HCV)
K. V. Sokolovsky, A. Z. Bonanos, P. Gavras +22
The Hubble Source Catalog (HSC) combines lists of sources detected on images obtained with the WFPC2, ACS and WFC3 instruments aboard the Hubble Space Telescope (HST) available in…
The Hubble Catalog of Variables
P. Gavras, A. Z. Bonanos, I. Bellas-Velidis +14
The Hubble Catalog of Variables (HCV) is a 3 year ESA funded project that aims to develop a set of algorithms to identify variables among the sources included in the Hubble Source…