The CARMA-NRO Orion Survey: Core Emergence and Kinematics in the Orion A Cloud

Shuo Kong, Héctor G. Arce, Anneila I. Sargent, Steve Mairs, Ralf S. Klessen, John Bally, Paolo Padoan, Rowan J. Smith, María José Maureira, John M. Carpenter, Adam Ginsburg, Amelia M. Stutz, Paul Goldsmith, Stefan Meingast, Peregrine McGehee, Álvaro Sánchez-Monge, Sümeyye Suri, Jaime E. Pineda, João Alves, Jesse R. Feddersen, Jens Kauffmann, Peter Schilke

We have investigated the formation and kinematics of sub-mm continuum

cores in the Orion A molecular cloud. A comparison between sub-mm

continuum and near infrared extinction shows a continuum core detection

threshold of $A_V\sim$ 5-10 mag. The threshold is similar to the star

formation extinction threshold of $A_V\sim$ 7 mag proposed by recent

work, suggesting a universal star formation extinction threshold among

clouds within 500 pc to the Sun. A comparison between the Orion A cloud

and a massive infrared dark cloud G28.37+0.07 indicates that Orion A

produces more dense gas within the extinction range 15 mag $\lesssim A_V

\lesssim$ 60 mag. Using data from the CARMA-NRO Orion Survey, we find

that dense cores in the integral-shaped filament (ISF) show sub-sonic

core-to-envelope velocity dispersion that is significantly less than the

local envelope line dispersion, similar to what has been found in nearby

clouds. Dynamical analysis indicates that the cores are bound to the

ISF. An oscillatory core-to-envelope motion is detected along the ISF.

Its origin is to be further explored.

Department of Astrophysics
The Astrophysical Journal
Publication date
Publication status
Peer reviewed
Austrian Fields of Science 2012
103003 Astronomy
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
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