collaborators

12 papers

astro-ph.HE2026

Model dependence of XRISM black-hole spin constraints in Cyg X-1

Andrzej A. Zdziarski, Swadesh Chand, Michal Szanecki +2

We study the persistent black hole X-ray binary Cyg X-1, recently observed by XRISM Resolve and simultaneously by NICER and NuSTAR in its hard spectral state. We confirm the result…

astro-ph.HE2026

On the assessment of the disk truncation and detection of type-II bursts from the accreting millisecond X-ray Pulsar IGR J17062-6143

Aditya Sow Mondal, Mahasweta Bhattacharya, Swarnendu Jana +2

We present a spectral analysis of the NuSTAR and NICER observations of the accreting millisecond X-ray pulsar IGR J17062-6143, performed in 2022. The source remained in the hard sp…

astro-ph.HE2026

Probing the accretion geometry of the transient accreting millisecond pulsar SAX J1808.4-3658: transitions to the propeller regime

Mahasweta Bhattacharya, Aditya S. Mondal, Gulab C. Dewangan

We analyze three NuSTAR observations and two NICER observations of the transient accreting millisecond pulsar SAX J1808.4-3658 in the hard spectral state during its most recent out…

astro-ph.HE2026

X-ray spectral and temporal evolution of atoll source 4U 1820-30 with AstroSat: detection of high frequency quasi-periodic oscillation

Subhasish Das, Vivek Kumar Agrawal, Parijat Thakur +4

AstroSat/LAXPC and SXT observed the persistent neutron star low-mass X-ray binary 4U 1820-30 between 2016 and 2022. During these observations, the hardness-intensity diagram (HID)…

astro-ph.HE2026

Understanding coronal geometry in NGC 4593 using Fourier frequency-resolved covariance and time-lag spectral analysis

Shree Suman, Mayukh Pahari, Gulab Dewangan +1

Understanding disc-corona geometry through X-ray reverberation variability studies in Seyfert galaxies is crucial, yet our knowledge mostly relies on flux-averaged mean spectral an…

astro-ph.HE2026

Evolution of the Inner Accretion Flow in Swift J1727.81613 across Intermediate States: Insights from Broadband Spectral and Timing Analysis

Swadesh Chand, Andrzej A. Zdziarski, Gulab C. Dewangan +1

We present a comprehensive broadband spectral and variability study of the newly detected black hole X-ray binary Swift~J1727.8--1613 in the intermediate states during its 2023 out…