CSO and CARMA OBSERVATIONS of L1157. I. A DEEP SEARCH for HYDROXYLAMINE (NH2OH)

Abstract

A deep search for the potential glycine precursor hydroxylamine (NH2OH) using the Caltech Submillimeter Observatory (CSO) at λ = 1.3 mm and the Combined Array for Research in Millimeter-wave Astronomy at λ = 3 mm is presented toward the molecular outflow L1157, targeting the B1 and B2 shocked regions. We report non-detections of NH2OH in both sources. We perform a non-LTE analysis of CH3OH observed in our CSO spectra to derive the kinetic temperatures and densities in the shocked regions. Using these parameters, we derive upper limit column densities of NH2OH of ≤1.4 � 1013 cm-2 and ≤1.5 � 1013 cm-2 toward the B1 and B2 shocks, respectively, and upper limit relative abundances of and ≤1.5 � 10-8, respectively.