collaborators

7 papers

astro-ph.HE2026

The strength of Type-C quasi-periodic oscillations in black hole X-ray binaries correlates with the jet inclination

F. M. Vincentelli, N. Bollemeijer, A. Veledina +10

X-ray quasi-periodic oscillations (QPOs) are a characteristic feature of low-mass X-ray binaries (LMXBs). These oscillations have been studied for decades and revealed a rich and c…

astro-ph.HE2026

Systematic assessment of disk truncation in the black hole X-ray binary Swift J1727.8-1613 using NICER

Ole König, James F. Steiner, Niek Bollemeijer +20

The 2023/24 NICER monitoring campaign of the 7 Crab bright black hole X-ray binary Swift J1727.8-1613 covered the outburst in almost all accretion states. High-quality data are ava…

astro-ph.HE2026

Covariance spectrum of MAXI J1820+070: On the nature of the Comptonizing flow

Shuai-Kang Yang, Bei You, Niek Bollemeijer +8

We present an analysis of the covariance spectrum of the black hole X-ray binary MAXI J1820+070 during its hard state. For the first time, we extend coherence and covariance studie…

astro-ph.HE2025

Recovery of the X-ray polarisation of Swift J1727.81613 after the soft-to-hard spectral transition

J. Podgorný, J. Svoboda, M. Dovčiak +34

We report on the detection of X-ray polarisation in the black-hole X-ray binary Swift J1727.81613 during its dim hard spectral state by the Imaging X-ray Polarimetry Explorer (I…

astro-ph.HE2025

Long term variability of Cygnus X-1. IX. A spectral-timing comparison of Cygnus X-1 and MAXI J1820+070 in the hard state

Arkadip Basak, Phil Uttley, Niek Bollemeijer +11

Cygnus X-1 is a persistent, high-mass black hole X-ray binary (BHXRB) which in the hard state shows many similar properties to transient BHXRBs, along with intriguing differences,…

astro-ph.HE2025

Variable QPO lags and reduced coherence between the disc and corona in MAXI J1820+070

Niek Bollemeijer, Phil Uttley

Quasi-periodic oscillations (QPOs) are observed in the hard state of many black hole X-ray binaries. Although their origin is unknown, they are strongly associated with the corona,…