Pulse frequency variations and timing noise of MXB 0656-072 during the 2007-2008 type I outbursts and implications for its magnetic field

Abstract

We aim to explore the properties of the Be/X-ray binary system MXB 0656-072 from a timing analysis perspective through an investigation of the RXTE/PCA and Fermi/GBM data during its 2007-2008 type I outbursts. We applied two new techniques, for the first time, along with the conventional Deeter method to produce higher-resolution power density spectra (PDS) of the torque fluctuations. We also investigated the spin frequency evolution of the source by utilising a pulse timing technique. The PDSs show a red noise pattern, with a steepness of $\Gamma \sim -2$ and a saturation timescale of $\sim$150 d, indicating that MXB 0656-072 is a disc-fed source. With the obtained long term spin frequency evolution, we reveal the torque-luminosity correlation of MXB 0656-072 for the first time. We also demonstrate that the frequency evolution is largely consistent with the Ghosh-Lamb model. In the RXTE/PCA observations, the pulsed emission disappears below $\sim$5$\times 10^{35}$ erg s${}^{-1}$, while the profiles remain stable above this value in our analysis time frame. We show that the magnetic field strength deduced from the torque model is compatible with the field strength of the pulsar derived from the cyclotron resonance scattering feature. Utilising the new distance of MXB 0656-072 measured by Gaia, we show that the spectral transition of MXB 0656-072 occurs at a luminosity that matches the expected theoretical transition from the subcritical to supercritical accretion regime.

arXiv comment7 pages, 5 figures. Accepted for publication in A&A

References in corpus (39)

• The Gaia mission
• Observations of Accreting Pulsars
• Be/X-ray binaries
• An analysis of the timing irregularities for 366 pulsars
• Spectral Formation in Accreting X-Ray Pulsars: Bimodal Variation of the Cyclotron Energy with Luminosity
• Spin-Up/Spin-Down of Magnetized Stars with Accretion Disks and Outflows
• Assessing the Role of Spin Noise in the Precision Timing of Millisecond Pulsars
• Cyclotron lines in highly magnetized neutron stars
• The critical accretion luminosity for magnetized neutron stars
• Magnetically Torqued Thin Accretion Disks
• NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-ray Pulsar Swift J0243.6+6124
• Searches for Continuous-Wave Gravitational Radiation
• The Ups & Downs of Accreting X-Ray Pulsars: Decade-long observations with the Fermi Gamma-Ray Burst Monitor
• The UTMOST pulsar timing programme II: Timing noise across the pulsar population
• A Frequency Glitch in an Accreting Pulsar
• The X-ray properties of Be/X-ray pulsars in quiescence
• The Effect of Quantized Magnetic Flux Lines on the Dynamics of Superfluid Neutron Star Cores
• Can disk-magnetosphere interaction models and beat frequency models for quasi-periodic oscillation in accreting X-ray pulsars be reconciled?
• Magnetic fields of neutron stars in X-ray binaries
• Spectrum formation in X-ray pulsars at very low mass accretion rate: Monte-Carlo approach
• Decade long RXTE monitoring observations of Be/X-ray binary pulsar EXO 2030+375
• Study of the cyclotron feature in MXB 0656-072
• Timing Studies on RXTE Observations of SAX J2103.5+4545
• Neutron star dynamics under time dependent external torques
• Stochastic processes for pulsar timing noise: fluctuations in the internal and external torques
• Timing properties of the X-ray accreting pulsar 1A 0535+262 studied with Insight-HXMT
• Parameter estimation of a two-component neutron star model with spin wandering
• Multi-wavelength study of the Be/X-ray binary MXB 0656-072
• New pulse profile variability associated with a glitch of PSR J0738-4042
• Pulse Frequency Fluctuations of Magnetars
• New insights into the Be/X-ray binary system MXB 0656-072
• Apparent dispersion in pulsar braking index measurements caused by timing noise
• Viscous timescale in high mass X-ray binaries
• Pulse Frequency Fluctuations of Persistent Accretion Powered Pulsars
• Comprehensive Timing and X-ray Spectral Analysis of GX 1+4
• Constraints on Undetected Long-Period Binaries in the Known Pulsar Population
• Timing analysis of Swift J0243.6+6124 with NICER and Fermi/GBM during the decay phase of the 2017-2018 outburst
• Spectral properties of the Be/X-ray pulsar 2S 1553-542 during Type II outbursts
• Temporal and spectral study of the X-ray pulsar 2S 1553-542 during the 2021 outburst