CSO and CARMA Observations of L1157. I. A Deep Search for Hydroxylamine (NH2OH)

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 {N}_{{NH}₂{OH}}/{N}_{{{H}}₂}≤slant 1.4× {10}^-8 and ≤1.5 × 10^-8, respectively.