papers

Publications (13)

astro-ph.GA2023

The intrinsic X-ray luminosity distribution of an optically-selected SDSS quasar population

Amy L. Rankine, James Aird, Angel Ruiz +1

In active galactic nuclei, the relationship between UV and X-ray luminosity is well studied (often characterised by ) but often with heterogeneous samples. We have pa…

astro-ph.HE2025

Characterising the X-ray variability of QSOs to the highest Eddington ratios and black hole masses with eROSITA light curves

Antonis Georgakakis, Angel Ruiz, Johannes Buchner +9

An important diagnostic of the inner structure of accretion flows onto supermassive black holes are the stochastic flux variations at X-ray wavelengths. Despite its significance, a…

astro-ph.CO2013

The Chandra Multi-Wavelength Project: Optical Spectroscopy and the Broadband Spectral Energy Distributions of X-ray Selected AGN

Markos Trichas, Paul J. Green, John D. Silverman +20

From optical spectroscopy of X-ray sources observed as part of ChaMP, we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic f…

astro-ph.CO2011

A Multiwavelength Study of Binary Quasars and Their Environments

Paul J. Green, Adam D. Myers, Wayne A. Barkhouse +5

We present Chandra X-ray imaging and spectroscopy for 14 quasars in spatially resolved pairs, part of a complete sample of binary quasars with small transverse separations drawn fr…

astro-ph.GA2012

Simultaneous X-ray and optical observations of true Type 2 Seyfert galaxies

Stefano Bianchi, Francesca Panessa, Xavier Barcons +9

We present the results of a campaign of simultaneous X-ray and optical observations of `true' Type 2 Seyfert galaxies candidates, i.e. AGN without a Broad Line Region (BLR). Out of…

astro-ph.GA2024

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…

astro-ph.IM2023

XMM2ATHENA, the H2020 project to improve XMM-Newton analysis software and prepare for Athena

Natalie A. Webb, Francisco J. Carrera, Axel Schwope +31

XMM-Newton, a European Space Agency observatory, has been observing the X-ray, ultra-violet and optical sky for 23 years. During this time, astronomy has evolved from mainly studyi…

astro-ph.CO2013

A tale of two feedbacks: star-formation in the host galaxies of radio-AGN

Marios Karouzos, Myungshin Im, Markos Trichas +19

Several lines of argument support the existence of a link between activity at the nuclei of galaxies, in the form of an accreting supermassive black hole, and star-formation activi…

astro-ph.GA2025

Revisiting the X-ray-to-UV relation of Quasars in the era of all-sky surveys

Maria Chira, Antonis Georgakakis, Angel Ruiz +8

The X-ray--to--UV relation of active galactic nuclei (AGNs), commonly parametrized via the monochromatic luminosities at and , reflects the energetic i…

astro-ph.IM2015

Status of the Silicon Photomultiplier Telescope FAMOUS for the Fluorescence Detection of UHECRs

Tim Niggemann, Pedro Assis, Pedro Brogueira +13

An established technique for the measurement of ultra-high-energy-cosmic-rays is the detection of the fluorescence light induced in the atmosphere of the Earth, by means of telesco…

astro-ph.HE2020

Forward modeling the multiwavelength properties of Active Galactic Nuclei: application to X-ray and WISE mid-infrared samples

Antonis Georgakakis, Angel Ruiz, Stephanie M. LaMassa

An empirical forward-modeling framework is developed to interpret the multiwavelength properties of Active Galactic Nuclei (AGN) and provide insights into the overlap and incomplet…

astro-ph.GA2026

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…

astro-ph.GA2022

The demographics of obscured AGN from X-ray spectroscopy guided by multiwavelength information

Brivael Laloux, Antonis Georgakakis, Carolina Andonie +10

A complete census of Active Galactic Nuclei (AGN) is a prerequisite for understanding the growth of supermassive black holes across cosmic time. A significant challenge toward this…