The Evolution of the Orbital Lightcurve of Hercules X-1 with 35 Day Phase

  title={The Evolution of the Orbital Lightcurve of Hercules X-1 with 35 Day Phase},
  author={Yuyang Wang and Denis A. Leahy},
  journal={The Astrophysical Journal},
Hercules X-1/HZ Hercules (Her X-1/HZ Her) is an X-ray binary monitored by multiple X-ray missions since the last century. With the abundance of long-term observations, we present a complete set of orbital lightcurves of Her X-1/HZ Her during the six states of the 35 day cycle in multiple energy bands. These illustrate in detail the changing lightcurve caused by the rotating twisted-tilted accretion disk surrounding the neutron star. The orbital lightcurves during the main high state are… 

Spectral Evolution of Hercules X-1 over Main High State from RXTE/PCA Observations

We test different X-ray spectrum models to find the one that best represents the observed Rossi X-ray Timing Explore/Proportional Counter Array (RXTE /PCA) spectra of Her X-1 during Main High state



Swift/BAT and RXTE/ASM Observations of the 35 day X-Ray Cycle of Hercules X-1

Swift/BAT and RXTE/ASM observations have monitored the X-ray binary system Her X-1 for approximately 14.5 yr each, and both were monitoring Her X-1 for a period of ∼5.5 yr. Here we study the 35 day

Rossi X-Ray Timing Explorer All-Sky Monitor Observations of the 35 Day Cycle of Hercules X-1

Her X-1 has been monitored nearly continuously in soft X-rays (2-12 keV) since 1996 February by the All-Sky Monitor on board the Rossi X-Ray Timing Explorer. We present an analysis of these

Light‐curve dip production through accretion stream–accretion disc impact in the HZ Her/Her X‐1 binary star system

We discuss the production of Hercules X-1's (Her X-1) light-curve dips through accretion stream impact on the disc. We model the binary system geometry, the position of the line of sight relative to

Observations of Her X-1 in low states during SRG/eROSITA all-sky survey

eROSITA (extended ROentgen Survey with an Imaging Telescope Array) instrument onboard the Russian-German ‘Spectrum-Roentgen-Gamma’ (SRG) mission observed the Her X-1/HZ Her binary system in multiple

Optical clues to the nature of Hercules X-1/HZ Herculis

The 1d/sub ./7 optical light curve of Her X-1/HZ Her varies in a highly systematic fashion over the 35 day X-ray on-off cycle. These variations can be reproduced in some detail by a relatively simple

The optical and X-ray light curves of Hercules X-1

The Galactic neutron star X-ray binary Her X-1 displays a well-known 35-day superorbital modulation in its X-ray and optical light curves. Detected across a broad energy range, the modulation is

The 35-Day Cycle of Hercules X-1 in Multiple Energy Bands from MAXI and Swift/BAT Monitoring

Hercules X-1 (Her X-1) has been monitored by MAXI and by Swift/BAT for over a decade. Those observations are analyzed to measure the shape and energy dependence of the long-term average of the 35-day

Modelling RXTE/ASM observations of the 35-d cycle in Her X-1

Her X-1 exhibits a 35-d cycle in X-ray intensity: 'main high state-low state-short high state-low state', which is caused by a varying obscuration of the neutron star by a tilted-twisted precessing

Analysis of an eclipse ingress during a high state of Hercules X-1