29^th Seminar

A Dynamically Collapsing Cloud Core and a Precursor of a Core in a Filament Supported by Turbulent and Magnetic Pressures

Rei Furuya

Tokushima University

Abstract

To understand the formation of molecular cores, the eventual sites of star formation, it is not enough to know only the physical state of the star-forming high-density gas. One must also determine the velocity field and density structure of the more diffuse medium surrounding the dense gas. One can go as far as saying that understanding the origin of molecular cores is equivalent to knowing the initial and boundary conditions of the gravitational collapse. In this talk, I will describe how, as a result of local turbulent disspation over approximately a free-fall time, in filamentary molecular clouds supported by magnetic and turbulent pressure, (i) a gravitationally unstable core is formed, and how (ii) that core undergoes a runaway collapse. I will report on observations of proto-star formation regions. Furthermore, I will present a possible serendipitous discovery of a protocore and discuss its implications on the formation mechanisms of molecular cores.