activity
20022026
most citedFalse periodicities in quasar time-domain surveys

298 citations · 1.5k across the 41 of their papers we have counts for

collaborators

42 papers

astro-ph.HE2026

25 Years of Mrk 421 with XMM-Newton: Unveiling Structured Jets and Energy-Dependent Escape

Tek P. Adhikari, Gopal Bhatta, Sangeetha Kizhakkekalam +4

We present a long-term X-ray spectral and timing analysis of the TeV blazar Mrk~421 based on nearly a quarter century of archival \textit{XMM-Newton}/pn observations obtained betwe…

astro-ph.HE2026

The disk luminosity deficit as a tracer of receding disk during Soft-to-Hard transitions in Black Hole X-ray Binaries

Sai-En Xu, Bei You, Yi Long +4

Tracing the evolution of the thin accretion disk during the soft-to-hard state transition in black hole X-ray binaries (BHXRBs) remains difficult because conventional spectral esti…

astro-ph.GA2026

A Changing-Look Seyfert Discovered by eROSITA Reveals a Two-Component Broad-Line Region

Alex Markowitz, Mirko Krumpe, David Homan +12

Extreme sudden changes in the flow of accreting gas onto SMBHs manifest themselves via large-amplitude continuum variability and changes to broad Balmer emission profiles, driving…

astro-ph.HE2026

Large-amplitude modulations and hours-timescale variability in the early X-ray light curve of a tidal disruption flare

A. Malyali, A. Rau, P. Baldini +11

We present new X-ray, optical, and UV observations of the tidal disruption event candidate eRASSt J234402.9-352640, (hereafter J2344). Between 50 and 60 days after peak optical bri…

astro-ph.HE2026

A break in the X-ray loudness of Markarian 590: evidence for an AGN spectral state transition?

B. Palit, A. Rozanska, A. G. Markowitz +8

Using decade-long multi-band {\it Swift} observations of the changing-look AGN Markarian 590, we identify a clear break in the dependence of the X-ray loudness parameter $α_{\rm ox…

astro-ph.HE2025

Optical and cm follow-ups of the Changing-Look event in Mkn 590

Biswaraj Palit, Abhijeet Borkar, Agata Różańska +5

The Changing-Look active galactic nucleus Mkn 590 is currently in a rejuvenated state, exhibiting a contemporaneous flux rise across X-rays, UV, optical and cm wavelengths. In this…