Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-02-03
Astronomy and Astrophysics
Astrophysics
Accepted for publication in A&A
Scientific paper
10.1051/0004-6361:20054634
Lada et al. recently presented a detailed near-infrared extinction map of Globule G2 in the Coalsack molecular cloud complex, showing that this starless core has a well-defined central extinction minimum. We propose a model for G2 in which a rapid increase in external pressure is driving an approximately symmetric compression wave into the core. The rapid increase in external pressure could arise because the core has recently been assimilated by the Coalsack cloud complex, or because the Coalsack has recently been created by two large-scale converging flows. The resulting compression wave has not yet converged on the centre of the core, so there is a central rarefaction. The compression wave has increased the density in the swept-up gas by about a factor of ten, and accelerated it inwards to speeds of order $0.4 {\rm km} {\rm s}^{-1}$. It is shown that even small levels of initial turbulence destroy the ring seen in projection almost completely. In the scenario of strong external compression that we are proposing this implies that the initial turbulent energy in this globule is such that $E_{{\rm turb}} / E_{{\rm grav}} \le 2 %$. Protostar formation should occur in about $40,000 {\rm years}$.
Goodwin Simon P.
Hennebelle Patrick
Whitworth Anthony P.
No associations
LandOfFree
A dynamical model for the dusty ring in the Coalsack does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A dynamical model for the dusty ring in the Coalsack, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A dynamical model for the dusty ring in the Coalsack will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-484307