The Supernova Remnant G106.3+2.7 and Its Pulsar-Wind Nebula: Relics of Triggered Star Formation in a Complex Environment

We propose that the pulsar nebula associated with the pulsar J2229+6114 and the supernova remnant (SNR) G106.3+2.7 are the result of the same supernova explosion. The whole structure is located at the edge of an H I bubble with extended regions of molecular gas inside. The radial velocities of both the atomic hydrogen and the molecular material suggest a distance of 800 pc. At this distance, the SNR is 14 pc long and 6 pc wide. Apparently, the bubble was created by the stellar wind and supernova explosions of a group of stars in its center, which also triggered the formation of the progenitor star of G106.3+2.7. The progenitor star exploded at or close to the current position of the pulsar, which is at one end of the SNR rather than at its center. The expanding shock wave of the supernova explosion created a comet-shaped supernova remnant by running into dense material and then breaking out into the inner part of the H I bubble. A synchrotron nebula with a shell-like structure (the "Boomerang") of length 0.8 pc was created by the pulsar wind interacting with the dense ambient medium. The expanding shock wave created an H I shell of mass 0.4 M☉ around this nebula by ionizing the atomic hydrogen in its vicinity.