Abstract:The relations between star formation and properties of molecular clouds are studied based on a sample of star forming regions in the Galactic Plane. Sources were selected by having radio recombination lines to provide identification of associated molecular clouds and dense clumps. Radio continuum and mid-infrared emission were used to determine star formation rates, while 13CO and submillimeter dust continuum emission were used to obtain masses of molecular and dense gas, respectively. We test whether total molecular gas or dense gas provides the best predictor of star formation rate. We also test two specific theoretical models, one relying on the molecular mass divided by the free-fall time, the other using the free-fall time divided by the crossing time. Neither is supported by the data. The data are also compared to those from nearby star forming regions and extragalactic data. The star formation "efficiency" , defined as star formation rate divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all the molecular gas. 

 Prof. Neal J. Evans II is Edward Randall, Jr. Centennial Professorship and chair of the Astronomy department of University of Texas at Austin, Texas, USA. He joined The University of Texas faculty in 1975, He has 500 refereed publications and conference contributions.

Awards and recognition: Prof. Evans is the author of two review articles (1999 and 2012) in the Annual Reviews of Astronomy and Astrophysics (ARA&A). He is a past member of the National Research Council's Committee on A&A, Past Chair of the NRAO's Program Advisory Committee and the Scientific Advisory Committee for ALMA, the principle investigator for “Cores to Disks” with Spitzer Space Telescope. In addition to leading a team executing a large key project on the ESA Herschel Space Observatory, he was the APRC Chair for three years (Cycles 0,1 and 2 of ALMA Science Operations. )