Long-term X-ray monitoring of LS I +61 303: analysis of spectral variability and flares
arXiv:1103.4205 · doi:10.1088/0004-637X/733/2/89
Abstract
We report on the full analysis of a Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) monitoring of the γ-ray binary system LS I +61 303. The data set covers 42 contiguous cycles of the system orbital motion. Analyzing this X-ray monitoring dataset, the largest to date for this source, we report on the variability of the orbital profile and the spectral distribution, and provide strong evidence for an anti-correlation between flux and spectral index (the higher the flux, the harder the spectral index). Furthermore, we present the analysis of two newly discovered ks-timescale flares, which present significant variability also on shorter timescales, and tend to occur at orbital phases between 0.6-0.9. However, a detailed timing analysis of the flares does not show any coherent or quasi-coherent (QPO) structure in their power spectra. We also investigated the possible appearance of the radio super-orbital modulation at X-rays energies, but we could not unambiguously detect such modulation in the system flux history, nor in the evolution of its orbital modulation fraction.
26 pages, 10 Figures, 1 Table ; Accepted to ApJ
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- Long-term TeV and X-ray Observations of the Gamma-ray Binary HESS J0632+057
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- Unveiling the super-orbital modulation of LS I +61 303 in X-rays
- Superorbital modulation of X-ray emission from gamma-ray binary LSI +61 303
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- Deep Chandra observations of TeV binaries II: LS 5039
- Detection of VHE γ-rays from HESS J0632+057 during the 2011 February X-ray outburst with the MAGIC Telescopes
- GeV detection of HESS J0632+057
- Simulations of an inhomogeneous stellar wind interacting with a pulsar wind in a binary system
- Discovery of a variable X-ray counterpart to HESS J1832-093: A new gamma-ray binary?
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- Swift observations of 1FGL J1018.6-5856
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- Searches for periodic neutrino emission from binary systems with 22 and 40 strings of IceCube
- The Multi-wavelength Characteristics of the TeV Binary LS I +61 303
- Modelling the correlated keV/TeV light curves of Be/gamma-ray binaries
- Does the gamma-ray binary LS I +61°303 harbor a magnetar?
- A precessing stellar disk model for superorbital modulations of the gamma-ray binary LS I+61 303
- Rapid X-ray variability of the gamma-ray binary LS I+61 303
- Optical microflares in LS I +61 303 and the search for their multiwavelength counterpart
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