The Nature of the Dense Core Population in the Pipe Nebula: A Survey of NH 3 , CCS, and HC 5 N Molecular Line Emission

Abstract

Recent extinction studies of the Pipe Nebula (d = 130 pc) reveal many cores spanning a range in mass from 0.2 to 20.4 M☉. These dense cores were identified via their high extinction and comprise a starless population in a very early stage of development. Here we present a survey of NH3 (1,1), NH3 (2,2), CCS (21-10), and HC5N (9,8) emission toward 46 of these cores. An atlas of the 2MASS extinction maps is also presented. In total, we detect 63% of the cores in NH3 (1,1), 22% in NH3 (2,2), 28% in CCS, and 9% in HC5N emission. We find the cores are associated with dense gas (~104 cm‑3) with 9.5 K