The Multi-wavelength Characteristics of the TeV Binary LS I +61°303
Abstract
We study the characteristics of the TeV binary LS I+61°303 in radio, soft X-ray, hard X-ray, and gamma-ray (GeV and TeV) energies. The long-term variability characteristics are examined as a function of the phase of the binary period of 26.496 days as well as the phase of the superorbital period of 1626 days, dividing the observations into a matrix of 10 × 10 phases of these two periods. We find that the long-term variability can be described by a sine function of the superorbital period, with the phase and amplitude systematically varying with the binary period phase. We also find a definite wavelength-dependent change in this variability description. To understand the radiation mechanism, we define three states in the orbital/superorbital phase matrix and examine the wideband spectral energy distribution. The derived source parameters indicate that the emission geometry is dominated by a jet structure showing a systematic variation with the orbital/superorbital period. We suggest that LS I+61°303 is likely a microquasar with a steady jet.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2016
- DOI:
- 10.3847/0004-637X/823/2/134
- arXiv:
- arXiv:1603.09109
- Bibcode:
- 2016ApJ...823..134S
- Keywords:
-
- gamma rays: general;
- radiation mechanisms: non-thermal;
- stars: emission-line;
- Be;
- stars: individual: LS I +61°303;
- X-rays: binaries;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 10 pages, 7 figures, accepted for publication in ApJ