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20242026
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14 papers · 1 filter

astro-ph.GA2026

Accretion-disk sizes in two quasars with interferometrically resolved broad-line regions at and

Francisco Pozo Nuñez, Eduardo Bañados, Swayamtrupta Panda +3

We present the first direct comparison between accretion-disk (AD) and broad-line region (BLR) sizes in quasars at z > 2, combining continuum reverberation mapping with interferome…

astro-ph.GA2026

HALO II: Constraining Hubble constant through continuum delay fitting of Fairall 9

Amit Kumar Mandal, Francisco Pozo Nuñez, Vikram Kumar Jaiswal +28

The Hubble tension remains one of the most significant unresolved problems in modern cosmology. A key question is whether it may arise from underestimated systematic uncertainties…

astro-ph.GA2026

Consistency between X-ray and UV-Optical reverberation measurements in NGC 5548

Amit Kumar Mandal, Bożena Czerny, Michal Dovčiak +2

The hard X-rayemitting hot corona is a key component of active galaxies. Constraints on the hot corona height can be derived from reverberation studies in both the X-ray and opt…

astro-ph.GA2026

Ultraviolet variability in Radio-Loud Active Galactic Nuclei observed by UVIT onboard AstroSat

M. Reshma, C. S. Stalin, Amit Kumar Mandal +3

Radio-loud active galactic nuclei (AGN) are among the most luminous objects in the Universe, emitting radiation from low-energy radio waves to high energy -rays. They are well k…

astro-ph.GA2025

HALO I: Photometric continuum reverberation mapping of Fairall 9

Amit Kumar Mandal, Francisco Pozo Nuñez, Vikram Kumar Jaiswal +23

We investigate the origin of inter-band continuum time delays in active galactic nuclei (AGNs) to study the structure and properties of their accretion disks. We aim to measure the…

astro-ph.GA2025

Standardizing reverberation-mapped H active galactic nuclei using time-averaged radiusluminosity relations with 5100\,Å\,, broad H, and narrow \OIII\ luminosities

Shulei Cao, Amit Kumar Mandal, Michal Zajaček +1

Active galactic nuclei (AGN) have been studied as alternate probes in cosmology due to their large and stable luminosities and broad redshift range. Previously it was shown that hi…