Timing properties of the X-ray accreting pulsar 1A 0535+262 studied with Insight-HXMT

Abstract

We report results on the timing analysis of the 2020 giant outburst of 1A 0535+262, using broadband data from Insight-HXMT. The analysis of the pulse profile evolution from the sub-critical luminosity to super-critical luminosity regime is presented for the first time. We found that the observed pulse profile exhibits a complex dependence on both energy and luminosity.A dip structure at the energy of the cyclotron resonant scattering features (CRSFs) is found for the first time in the pulse fraction-energy relation of 1A 0535+262, when the outburst evolves in a luminosity range from 4.8 $\times 10^{37}$ erg s${}^{-1}$ to 1.0 $\times 10^{38}$ erg s${}^{-1}$. The observed structure is luminosity dependent and appears around the source critical luminosity ($\sim$ 6.7 $\times 10^{37}$ erg s${}^{-1}$).

References in corpus (31)

• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite
• Spectral Formation in Accreting X-Ray Pulsars: Bimodal Variation of the Cyclotron Energy with Luminosity
• Stingray: A Modern Python Library For Spectral Timing
• Cyclotron lines in highly magnetized neutron stars
• V0332+53 in the outburst of 2004--2005: luminosity dependence of the cyclotron line and pulse profile
• The Medium Energy (ME) X-ray telescope onboard the Insight-HXMT astronomy satellite
• NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-ray Pulsar Swift J0243.6+6124
• Discovery of oscillations above 200 keV in a black hole X-ray binary with Insight-HXMT
• Timing Characteristics of the Hard X-ray Emission from Bright X-ray Pulsars Based on INTEGRAL Data
• Completing the puzzle of the 2004-2005 outburst in V0332+53: the brightening phase included
• 4U 0115+63 from RXTE and INTEGRAL Data: Pulse Profile and Cyclotron Line Energy
• Luminosity dependence of the cyclotron line and evidence for the accretion regime transition in V 0332+53
• Insight-HXMT observations of jet-like corona in a black hole X-ray binary MAXI J1820+070
• A 0535+26 in the August/September 2005 outburst observed by RXTE and INTEGRAL
• Positive correlation between the cyclotron line energy and luminosity in sub-critical X-ray pulsars: Doppler effect in the accretion channel
• 4U 0115+63: phase lags and cyclotron resonant scattering
• Transient X-ray pulsar V0332+53: pulse phase-resolved spectroscopy and the reflection model
• X-Ray and Optical Observations of A 0535+26
• Hot disk of the Swift J0243.6+6124 revealed by Insight-HXMT
• The pre-outburst flare of the A 0535+26 August/September 2005 outburst
• Analyzing X-ray pulsar profiles: geometry and beam pattern of A 0535+26
• Formation of phase lags at the cyclotron energies in the pulse profiles of magnetized, accreting neutron stars
• Changes in the cyclotron line energy on short and long timescales in V 0332+53
• Her X-1: the positive cyclotron line energy / luminosity correlation
• Study of timing and spectral properties of the X-ray pulsar 1A 0535+262 during the giant outburst in 2020 November-December
• A Puzzling Paucity of Double Peaked X-ray Pulsars
• Constraining compactness and magnetic field geometry of X-ray pulsars from the statistics of their pulse profiles
• Insight-HXMT observations of Swift J0243.6+6124: the evolution of RMS pulse fractions at super-Eddington luminosity
• Switches between accretion structures during flares in 4U 1901+03
• Pulsating iron spectral features in the emission of X-ray pulsar V0332+53

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• X-ray Polarimetry of the accreting pulsar 1A~0535+262 in the supercritical state with PolarLight
• X-Ray Views of Galactic Accreting Pulsars in High-Mass X-Ray Binaries
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• The unaltered pulsar: GRO J1750-27, a super-critical X-ray neutron star that does not blink an eye
• Broadband study of the Be X-ray binary RX J0520.5-6932 during its outburst in 2024
• Deep search for gamma-ray emission from the accreting X-ray pulsar 1A 0535+262
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