15 papers · 1 filter
A positive period derivative in the quasi-periodic eruptions of ZTF19acnskyy
Joheen Chakraborty, Saul A. Rappaport, Riccardo Arcodia +9
We report the first direct measurement of the period derivative in a quasi-periodic eruption (QPE), finding a smoothly increasing period with $\dot{P}\approx (1.7\pm 0.02)\times10^…
X-ray Spectral-Timing Properties of Tidal Disruption Events
Joheen Chakraborty, Megan Masterson, Andrew Mummery +4
We perform the first systematic study of the minute-to-hours-timescale stochastic variability observed in the X-ray luminosity of tidal disruption events (TDEs) using XMM-Newton da…
Disk-to-Corona State Transition and Extreme X-ray Variability in the Tidal Disruption Event AT2019teq
Vera Berger, Erin Kara, Joheen Chakraborty +2
We present a five-year X-ray spectral and timing analysis of the optically selected Tidal Disruption Event (TDE) AT2019teq, which displays extreme variability, including order-of-m…
NICER observations reveal doubled timescales in Ansky's quasi-periodic eruptions (QPEs)
L. Hernández-GarcÃa, P. Sánchez-Sáez, J. Chakraborty +11
Quasi-periodic eruptions (QPEs) are recurring X-ray bursts originating from the vicinity of supermassive black holes, but their driving mechanisms remain under debate. This study a…
Prospects for EMRI/MBH parameter estimation using Quasi-Periodic Eruption timings: short-timescale analysis
Joheen Chakraborty, Lisa V. Drummond, Matteo Bonetti +11
Quasi-Periodic Eruptions (QPEs) are luminous, recurring X-ray outbursts from galactic nuclei, with timescales of hours to days. While their origin remains uncertain, leading models…
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,…