The dense molecular cores in the IRAS 21391+5802 region

¹ Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, 50125 Firenze, Italy e-mail: mbeltran@arcetri.astro.it
² Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
³ Departament d'Astronomia i Meteorologia, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona, Catalunya, Spain
⁴ Institut de Ciències de l'Espai (CSIC)-IEEC, Gran Capità 2, 08034 Barcelona, Catalunya, Spain

Received: 26 April 2004
Accepted: 2 July 2004

Abstract

We present a detailed kinematical study and modeling of the emission of the molecular cores at ambient velocities surrounding IRAS 21391+5802, an intermediate-mass protostar embedded in IC 1396N. The high-density gas emission is found in association with three dense cores associated with the YSOs BIMA 1, BIMA 2, and BIMA 3. The CS () and CH₃OH () emission around BIMA 1 has been modeled by considering a spatially infinitely thin ring seen edge-on by the observer. From the model we find that CS is detected over a wider radii range than CH₃OH. A bipolar outflow is detected in the CS () line centered near BIMA 1. This outflow could be powered by a yet undetected YSO, BIMA 1W, or alternatively could be part of the BIMA 1 molecular outflow. The CS and CH₃OH emission associated with the intermediate-mass protostar BIMA 2 is highly perturbed by the bipolar outflow even at cloud velocities, confirming that the protostar is in a very active stage of mass loss. For YSO BIMA 3 the lack of outflow and of clear evidence of infall suggests that both outflow and infall are weaker than in BIMA 1, and that BIMA 3 is probably a more evolved object.