Gravitational collapse of the OMC-1 region

Abstract

We have investigated the global dynamical state of the integral shaped filament in the Orion A cloud using new N2H+ (1−0) large-scale, IRAM 30 m observations. Our analysis of its internal gas dynamics reveals the presence of accelerated motions towards the Orion Nebula Cluster, showing a characteristic blue-shifted profile centred at the position of the OMC-1 South region. The properties of these observed gas motions (profile, extension, and magnitude) are consistent with the expected accelerations for the gravitational collapse of the OMC-1 region and explain both the physical and kinematic structure of this cloud.