Magnetic Fields and Carbon Chemistry in Star Forming Regions

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This proposal focusses on two timely and important questions in modern astrophysics: 1) Which star & planet forming environments form biologically important molecules, and what kinds of chemistries dominate in different regions? 2) How do magnetic fields affect the shape and structure of star forming molecular clouds, and how does this influence the subsequent formation of stars and planets? To address these questions, I request funding to support two long-term research projects. 1) A study of Complex Organic Molecules (COM) vs Carbon Chain Molecules (CCM) in High Mass Star Forming (HMSF) regions Complex molecules have been identified in many different environments in space. While much attention has been given to the astrobiological importance of COMs, CCMs are also biologically important because even simple ring species like c-C3H2 may be key to producing larger biomolecules; such as carbohydrates. While most studies to date have focussed on a few isolated, low mass cores, most stars (including low mass stars) form in HMSF regions. COMs are known to be abundant in hot cores in HMSF regions. CCMs, however, are thought to be deficient in these regions. Therefore, in this project we will embark upon an observational campaign to detect and map a variety of CCMs in a sample of HMSF regions. Modeling of the observations will help us understand the time scales and physical conditions (i.e. density, UV field strength, temperature, etc) that are important in setting the observed abundances in HMSF regions and directly compare this to similar observational and theoretical work for low mass cores. 2) A study of the 3D morphology and strength of large-scale magnetic fields associated with star forming molecular clouds. Studies have shown that magnetic fields can be important in the formation and evolution of molecular clouds. In particular, it has been proposed that a helical magnetic field wrapping around a cloud could stabilize it against gravitational collapse. The existence of such helical fields, however, has lacked observational confirmation. This is mainly because the traditional methods to measure magnetic field strengths in clouds have a number of inherent difficulties. Over the past few years we have created a new and novel technique to measure the line-of-sight magnetic field (Blos) in molecular clouds. Using this technique, we found that Blos was consistent helical fields wrapping around the clouds but, due to limitations in the data, we could not rule out other geometries. In this project we propose to refine our technique and have embarked on a project at the VLA telescope to survey a sample of molecular clouds with greater sensitivity. The goal is to produce highly sensitive, high resolution maps of the 3D magnetic field geometry in molecular clouds with small enough errors that we can confidently determine the magnetic field geometry.