Direct observation of a sharp transition to coherence in Dense Cores

Details Direct observation of a sharp transition to coherence in Dense Cores Direct observation of a sharp transition to coherence in Dense Cores

2010-02-15

arxiv.org/abs/1002.2946v1

Astronomy and Astrophysics

Astrophysics

Galaxy Astrophysics

Accepted for publication in ApJ Letters. 6 pages, 5 figures

Scientific paper

We present NH3 observations of the B5 region in Perseus obtained with the Green Bank Telescope (GBT). The map covers a region large enough (~11'x14') that it contains the entire dense core observed in previous dust continuum surveys. The dense gas traced by NH3(1,1) covers a much larger area than the dust continuum features found in bolometer observations. The velocity dispersion in the central region of the core is small, presenting subsonic non-thermal motions which are independent of scale. However, it is thanks to the coverage and high sensitivity of the observations that we present the detection, for the first time, of the transition between the coherent core and the dense but more turbulent gas surrounding it. This transition is sharp, increasing the velocity dispersion by a factor of 2 in less than 0.04 pc (the 31" beam size at the distance of Perseus, ~250 pc). The change in velocity dispersion at the transition is ~3 km/s/pc. The existence of the transition provides a natural definition of dense core: the region with nearly-constant subsonic non-thermal velocity dispersion. From the analysis presented here we can not confirm nor rule out a corresponding sharp density transition.

Affiliated with

Also associated with

No associations

Rating

Direct observation of a sharp transition to coherence in Dense Cores 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 Direct observation of a sharp transition to coherence in Dense Cores, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Direct observation of a sharp transition to coherence in Dense Cores will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-597466