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arXiv · 1908.04488

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
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Abstract

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.

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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. 2019-08-13. The CARMA-NRO Orion Survey: Core Emergence and Kinematics in the Orion A Cloud. https://doi.org/10.3847/1538-4357/ab311e

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