skip to main content

Title: OPTICAL CONSTANTS OF NH{sub 3} AND NH{sub 3}:N{sub 2} AMORPHOUS ICES IN THE NEAR-INFRARED AND MID-INFRARED REGIONS

Ammonia ice has been detected on different astrophysical media ranging from interstellar medium (ISM) particles to the surface of various icy bodies of our solar system, where nitrogen is also present. We have carried out a detailed study of amorphous NH{sub 3} ice and NH{sub 3}:N{sub 2} ice mixtures, based on infrared (IR) spectra in the mid-IR (MIR) and near-IR (NIR) regions, supported by theoretical quantum chemical calculations. Spectra of varying ice thicknesses were obtained and optical constants were calculated for amorphous NH{sub 3} at 15 K and 30 K and for a NH{sub 3}:N{sub 2} mixture at 15 K over a 500-7000 cm{sup –1} spectral range. These spectra have improved accuracy over previous data, where available. Moreover, we also obtained absolute values for the band strengths of the more prominent IR features in both spectral regions. Our results indicate that the estimated NH{sub 3} concentration in ISM ices should be scaled upward by ∼30%.
Authors:
; ; ; ; ;  [1]
  1. Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, E-28006 Madrid (Spain)
Publication Date:
OSTI Identifier:
22270686
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 777; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMMONIA; ASTRONOMY; ASTROPHYSICS; COSMOCHEMISTRY; ICE; INFRARED SPECTRA; INTERMEDIATE INFRARED RADIATION; MIXTURES; NEAR INFRARED RADIATION; PLANETS; SOLAR SYSTEM; SURFACES