Chandra Probes the X-Ray Variability of M51 ULX-7: Evidence of Propeller Transition and X-Ray Dips on Orbital Periods

@article{Vasilopoulos2021ChandraPT,
  title={Chandra Probes the X-Ray Variability of M51 ULX-7: Evidence of Propeller Transition and X-Ray Dips on Orbital Periods},
  author={Georgios Vasilopoulos and Filippos Koliopanos and Frank Haberl and Helena Treiber and Murray Brightman and Hannah P. Earnshaw and A. Madoz G{\'u}rpide},
  journal={The Astrophysical Journal},
  year={2021},
  volume={909}
}
We report on the temporal properties of the ultraluminous X-ray (ULX) pulsar M51 ULX-7 inferred from the analysis of the 2018–2020 Swift/X-ray Telescope monitoring data and archival Chandra data obtained over a period of 33 days in 2012. We find an extended low flux state, which might be indicative of propeller transition, lending further support to the interpretation that the neutron star is rotating near equilibrium. Alternatively, this off-state could be related to a variable superorbital… 

Evolution of the Spin, Spectrum and Superorbital Period of the Ultraluminous X-Ray Pulsar M51 ULX7

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Long-term X-ray spectral evolution of ultraluminous X-ray sources: implications on the accretion flow geometry and the nature of the accretor

Context. The discovery of pulsations in several ultraluminous X-ray sources (ULXs) has demonstrated that a fraction of them are powered by super-Eddington accretion onto neutron stars (NSs). This has

Quasi-periodic dipping in the ultraluminous X-ray source, NGC 247 ULX-1

Most ultraluminousX-ray sources (ULXs) are believed to be stellar mass black holes or neutron stars accreting beyond the Eddington limit. Determining the nature of the compact object and the

High-mass X-ray binaries with Be donors as ultraluminous X-ray sources

  • S. Karino
  • Physics
    Monthly Notices of the Royal Astronomical Society
  • 2021
Since the detection of X-ray pulses from ultraluminous X-ray sources (ULXs) in 2014, neutron stars have been considered as their central objects. However, it remains unclear how neutron stars can

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