NOAO >   Observing Info >   Approved Programs >   2003B-0033

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Proposal Information for 2003B-0033


PI: Patrick Hartigan, Rice University, hartigan@sparky.rice.edu
Address: Physics Department, 6100 S Main, Houston, TX 77005, USA

Title: The Anatomy of Magnetic Precursors and C-Shocks

Abstract: This proposal to use NIRI in spectroscopic mode follows up on the recent HST discovery of a magnetic precursor located along the leading edge of a molecular outflow from a region of massive star formation. Magnetic precursors and C-shocks arise when magnetic waves accelerate ions ahead of the front and a layer of warm gas forms there when the ions collide with neutrals and with dust. Precursors and C-shocks are important to understand because they provide the means by which high velocity flows from young stars transfer energy and momentum to their parent molecular clouds. The physics that governs precursor heating is complex, and poorly-constrained observationally and theoretically. The proposed long slit observations will follow the intensities of [Fe II], Br-(gamma), and 1 - 0, 2 - 1, and 3 - 2 transitions of H_2 as gas moves through the precursor and into the jump shock. These observations will provide the first clues as to how the physics operates in these shocks that dominate the dynamics and generate much of the observed morphology within molecular clouds. This is a resubmission of a proposal granted Gemini queue time in 2002B - no observations were performed during that cycle owing to mechanical difficulties with NIRI.


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NOAO >   Observing Info >   Approved Programs >   2003B-0033

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