122 citations · 954 across the 47 of their papers we have counts for
11 papers · 1 filter
Energy dependence of the X-ray power spectrum in NGC4051 and NGC4395
V. A. Diamantopoulos, I. E. Papadakis, A. Akylas +3
Active galactic nuclei (AGNs) exhibit strong variability across the electromagnetic spectrum on a wide range of timescales, particularly in X-rays where fluctuations are both rapid…
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…
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…
NuSTAR observations of heavily obscured Swift/BAT AGN: constraints on the Compton-thick AGN fraction
I. Georgantopoulos, A. Akylas
The all-sky hard X-ray survey performed by Swift/BAT allowed the detection of many heavily obscured Compton-thick AGN. In our previous work, we have identified more than 50 candida…