Connection between orbital modulation of H-alpha and gamma-rays in the Be/X-ray binary LSI+61303

Abstract

We studied the average orbital modulation of various parameters (gamma-ray flux, H-alpha emission line, optical V band brightness) of the radio- and gamma-ray emitting Be/X-ray binary LSI+61303. Using the Spearman rank correlation test, we found highly significant correlations between the orbital variability of the equivalent width of the blue hump of the H-alpha and Fermi-LAT flux with a Spearman p-value 2e-5, and the equivalent widths ratio EW_B/EW_R and Fermi-LAT flux with p-value 9e-5. We also found a significant anti-correlation between Fermi-LAT flux and V band magnitude with p-value 7.10^{-4}. All these correlations refer to the average orbital variability, and we conclude that the H-alpha and gamma-ray emission processes in LSI+61303 are connected. The possible physical scenario is briefly discussed.

accepted as a Letter in Astronomy and Astrophysics

References in corpus (10)

• Gamma-ray binaries and related systems
• Accretion vs colliding wind models for the gamma-ray binary LS I +61 303: an assessment
• Periodic very high energy gamma-ray emission from LS I +61 303 observed with the MAGIC telescope
• Joint H-alpha and X-Ray Observations of Massive X-Ray Binaries. II. The Be X-ray Binary and Microquasar LS I +61 303
• Associating long-term gamma-ray variability with the superorbital period of LS I 61 303
• VLBA images of the precessing jet of LSI+61303
• Superorbital modulation of X-ray emission from gamma-ray binary LSI +61 303
• Long-term periodicity in LSI+61303 as beat frequency between orbital and precessional rate
• H-alpha observations of the gamma-ray-emitting Be/X-ray binary LSI+61303: orbital modulation, disk truncation, and long-term variability
• H-alpha Emission Variability in the gamma-ray Binary LS I +61 303

Cited by in corpus (6)

• Orbital variability of the optical linear polarization of the $\gamma$-ray binary LS I +61 303 and new constraints on the orbital parameters
• Evidence of coupling between the thermal and nonthermal emission in the gamma-ray binary LS I +61 303
• Superorbital modulation at GeV energies in the gamma-ray binary LS I +61 303
• Optical and Near-Infrared Monitoring of Gamma-ray Binaries Hosting Be Stars
• Achromatic rapid flares in hard X-rays in the $\gamma$-ray binary LS I +61-303
• Optical microflares in LS I +61 303 and the search for their multiwavelength counterpart