collaborators

5 papers

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.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.HE2025

A UV to X-Ray View of Soft Excess in Type 1 Active Galactic Nuclei. II. Broadband Correlations

Shi-Jiang Chen, Jun-Xian Wang, Jia-Lai Kang +5

The physical origin of soft X-ray excess (SE) is a long lasting question, with two prevailing theories -- ``warm corona'' and ``ionized reflection'' -- dominating the discussion. I…

astro-ph.HE2025

The Average Soft X-ray Spectra of eROSITA Active Galactic Nuclei

Shi-Jiang Chen, Johannes Buchner, Teng Liu +16

Context. AGNs are strong X-ray emitters shaped by disk-corona interactions. The soft excess (0.5-2.0 keV) reveals key information about the "warm corona" bridging the disk and hot…

astro-ph.HE2024

A UV to X-ray view of soft excess in type 1 AGNs: I. sample selection and spectral profile

Shi-Jiang Chen, Jun-Xian Wang, Jia-Lai Kang +5

A core sample of 59 unobscured type 1 AGNs with simultaneous XMM-Newton X-ray and UV observations is compiled from archive to probe the nature of soft X-ray excess (SE). In the fir…