Astrochemistry

Publication Abstract

Evidence for Spectral Linewidth Change with Telescope Beamwidth: Support for the Identification Of Interstellar Urea

H.-L. Kuo, A. J. Remijan, L. E. Snyder, L. W. Looney, D. N. Friedel, F. J. Lovas, Benjamin J. McCall, and J. M. Hollis

High angular resolution observations of urea (NH2)2O and other complex molecules in the Sgr B2 (N-LMH) hot core utilizing CARMA (Combined Array for Research in Millimeter-wave Astronomy) have shown that the observed spectral linewidths are a function of the array beamwidths (full width at half maximum or FWHM). A comparison between the SEST 15 m data (Nummelin et al. 1998), BIMA array data, and CARMA data demonstrates that the measured spectral linewidths decrease with telescope beamwidths. The small synthesized beam of CARMA (2.6" x 2") not does not detect (resolves out) the ux from extended structures but does detect the narrow individual lines that are blended within the extended structure. This simplifies the line fitting process and spectral analysis, which reduces the uncertainty of the calculated beam-averaged column density of urea.

Presented at the Midwest Astrochemistry Meeting 2011



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© 2015, D. N. Friedel