The system of molecular clouds in the Gould Belt

Abstract

Based on high-latitude molecular clouds with highly accurate distance estimates taken from the literature, we have redetermined the parameters of their spatial orientation. This systemcan be approximated by a 350 × 235 × 140 pc ellipsoid inclined by the angle i = 17° ± 2° to the Galactic plane with the longitude of the ascending node l_Ω = 337° ± 1°. Based on the radial velocities of the clouds, we have found their group velocity relative to the Sun to be (u₀, v₀, w₀) = (10.6, 18.2, 6.8) ± (0.9, 1.7, 1.5) km s⁻¹. The trajectory of the center of the molecular cloud system in the past in a time interval of ~60 Myr has been constructed. Using data on masers associated with low-mass protostars, we have calculated the space velocities of the molecular complexes in Orion, Taurus, Perseus, and Ophiuchus. Their motion in the past is shown to be not random.