A Detailed Study of 2S 0114+650 with the RXTE

Abstract

We present the results of a detailed study of the high mass X-ray binary 2S 0114+650 made with the pointed instruments onboard the Rossi X-ray Timing Explorer. The spectral and temporal behaviour of this source was examined over the pulse, orbital, and super-orbital timescales, covering $\sim$2 cycles of the 30.7 d super-orbital modulation. Marginal evidence for variability of the power law photon index over the pulse period was identified, similar to that observed from other X-ray pulsars. If this variability is real it can be attributed to a varying viewing geometry of the accretion region with the spin of the neutron star. Variability of the neutral hydrogen column density over the orbital period was observed, which we attribute to the line of sight motion of the neutron star through the dense circumstellar environment. A reduction in the power law photon index was observed during the orbital maximum, which we speculate is due to absorption effects as the neutron star passes behind a heavily absorbing region near the base of the supergiant companion's wind. No significant variability of the column density was observed over the super-orbital period, indicating that variable obscuration by a precessing warp in an accretion disc is not the mechanism behind the super-orbital modulation. In contrast, a significant increase in the power law photon index was observed during the super-orbital minimum. We conclude that the observed super-orbital modulation is tied to variability in the mass accretion rate due to some as yet unidentified mechanism.

22 pages, 27 figures, accepted for publication in MNRAS after moderate revision

References in corpus (16)

• Physics of Strongly Magnetized Neutron Stars
• Physical Parameters and Wind Properties of Galactic Early B Supergiants
• A model for cyclotron resonance scattering features
• A long-period, violently-variable X-ray source in a young SNR
• A Systematic Search for Periodicities in RXTE/ASM Data
• INTEGRAL survey of the Cassiopeia region in hard X rays
• Hard Spectra of X-Ray Pulsars from INTEGRAL Data
• The origin of long-period X-ray pulsars
• The X-ray binary 2S0114+650=LSI+65 010:A slow pulsar or tidally-induced pulsations?
• Superorbital Period in the High Mass X-ray Binary 2S 0114+650
• The Orbit of the Eclipsing X-ray Pulsar EXO 1722-363
• Joint H-alpha and X-ray Observations of Massive X-ray Binaries. I. The B-Supergiant System LS I +65 010 = 2S 0114+650
• INTEGRAL High Energy Observations of 2S 0114+65
• A new symbiotic low mass X-ray binary system: 4U 1954+319
• Evolution of the periodicities in 2S 0114+650
• Luminosity dependent study of the High Mass X-ray Binary Pulsar 4U~0114+65 with ASCA

Cited by in corpus (34)

• Cyclotron lines in highly magnetized neutron stars
• High-Mass X-ray Binaries in the Milky Way: A closer look with INTEGRAL
• Towards a unified view of inhomogeneous stellar winds in isolated supergiant stars and supergiant high mass X-ray binaries
• Clustering between high-mass X-ray binaries and OB associations in the Milky Way
• Superorbital Periodic Modulation in Wind-Accretion High-Mass X-ray Binaries from Swift BAT Observations
• Spectral and Timing Nature of the Symbiotic X-ray Binary 4U 1954+319: The Slowest Rotating Neutron Star in an X-ray Binary System
• X-ray irradiation of the winds in binaries with massive components
• Finding a 24-day orbital period for the X-ray binary 1A 1118-616
• Long-term X-ray monitoring of LS I +61 303: analysis of spectral variability and flares
• Evolution of Spin, Orbital, and Superorbital Modulations of 4U 0114+650
• Super-Orbital Variability in Hard X-rays
• Correlated optical/X-ray variability in the high-mass X-ray binary SAX J2103.5+4545
• The 5 hr pulse period and broadband spectrum of the Symbiotic X-ray Binary 3A 1954+319
• An XMM-Newton Spectral and Timing Study of IGR J16207-5129: An Obscured and Non-Pulsating HMXB
• An XMM-Newton and NuSTAR study of IGR J18214-1318: a non-pulsating high-mass X-ray binary with a neutron star
• Is superorbital modulation in SMC X-1 caused by absorption in warped precessing accretion disc?
• XMM-Newton spectroscopy of the accreting magnetar candidate 4U0114+65
• Long-term Hard X-ray Monitoring of 2S 0114+65 with INTEGRAL/IBIS
• Spin and Spectral Variations of Peculiar High-Mass X-ray Binary 4U 2206+54
• On the super-orbital modulation of supergiant high mass X-ray binaries
• The VLT-FLAMES Tarantula survey XX. The nature of the X-ray bright emission line star VFTS 399
• Understanding the coexistence of spin-up and spin-down behaviors in long period X-ray pulsars
• Superorbital Modulation in the High-Mass X-ray Binary 4U 1538-52, and Possible Modulation in IGR J16393-4643
• Is 4U 0114+65 an eclipsing HMXB?
• A Study of the 20 Day Superorbital Modulation in the High-Mass X-ray Binary IGR J16493-4348
• Discovery of a magnetic neutron star in X-ray transient IGR J01583+6713
• Investigating the superorbital modulations in 4U 1909+07, IGR J16418-4532 and IGR J16479-4514 with Swift XRT, BAT and NuSTAR observations
• The Orbital Parameters of the Eclipsing High-Mass X-ray Binary Pulsar IGR J16493-4348 from Pulsar Timing
• X-ray irradiation of the stellar wind in HMXBs with B supergiants: Implications for ULXs
• Probing the Mysteries of the X-Ray Binary 4U 1210-64 with ASM, PCA, MAXI, BAT and Suzaku
• Clumpy jets from black hole-massive star binaries as engines of Fast Radio Bursts
• Nustar observation of the binary system 4U 0114+65
• The superslow pulsation X-ray pulsars in high mass X-ray binaries
• Astrophysical parameters of LS 437 and the nature of X0726-260