A multiwavelength investigation of the relationship between 2CG 135+1 and LSI+61°303

We present the results of a multiwavelength monitoring campaign targeting the gamma-ray source 2CG 135+1 in an attempt to confirm the association of this object with the radio/Be/X-ray binary system LSI +61 degrees 303. The campaign included simultaneous radio, optical, infrared, and hard X-ray/gamma-ray observations carried out with a variety of instruments, covering (not continuously) almost three binary cycles of LSI +61 degrees 303 during the period 1994 April-July. Three separate OSSE observations of the gamma-ray source were carried out, covering different phases of the radio light curve. Hard X-ray/gamma-ray emission was detected from the direction of 2CG 135 + 1 during the first of these OSSE observations. The signal-to-noise ratio of the OSSE observations was insufficient to establish a spectral or intensity correlation of the high-energy emission with simultaneous radio, optical, and infrared emission of LSI +61 degrees 303. We briefly discuss the theoretical implications of our observations.