CSO and Carma Observations of L1157. I. A Deep Search for Hydroxylamine (NH_2OH)

A deep search for the potential glycine precursor hydroxylamine (NH_2OH) 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 NH_2OH in both sources. We perform a non-LTE analysis of CH_3OH 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 NH_2OH of ≤1.4 × 10^(13) cm^(−2) and ≤1.5 × 10^(13) cm^(−2) toward the B1 and B2 shocks, respectively, and upper limit relative abundances of N_(NH_2OH)/N_H_2 ≤ 1.4 x 10^(-8) and ≤1.5 × 10^(−8), respectively