Cold Dark Clouds: The Initial Conditions for Star Formation

Cold dark clouds are nearby members of the densest and coldest phase in the Galactic interstellar medium, and represent the most accessible sites where stars like our Sun are currently being born. In this review we discuss recent progress in their study, including the newly discovered IR dark clouds that are likely precursors to stellar clusters. At large scales, dark clouds present filamentary mass distributions with motions dominated by supersonic turbulence. At small, subparsec scales, a population of subsonic starless cores provides a unique glimpse of the conditions prior to stellar birth. Recent studies of starless cores reveal a combination of simple physical properties together with a complex chemical…