Electron impact dissociation of amorphous cis-methyl acetate ice analogs

Exposed amorphous water ice on comet 49P/Arend-Rigaux

“…Laboratory simulation to obtain water ice spectra at 85 K was carried out at the laboratory for low temperature astrochemistry at the Physical Research Laboratory (PRL) (Sivaraman, Mukherjee et al 2014). The experimental chamber is pumped to <10 -9 mbar containing a cold head holding zinc selenide (ZnSe) window cooled down to 85 K. Water molecules are introduced into the vacuum chamber condensed on to the cold surface at 85 K. Fourier Transform InfraRed (FTIR) spectrometer operating at mid-infrared region was used to record the InfraRed (IR) spectra.…”

Electron irradiation of carbon dioxide-carbon disulphide ice analog and its implication on the identification of carbon disulphide on Moon

“…As the number of oxygen atoms that are available for reaction is larger than the given amount of S atoms, other reactions involving O atoms do take place synthesizing CO 3 , O 3 and OCS. Synthesizing CO 3 could be via O atom addition to CO 2 , as given in equation 7, whereas for making O 3 , O atoms have to undergo a series of two-step reaction in synthesizing O 2 first and an addition of O atom to make O 3 , as given in equation (8). However, synthesizing OCS could occur via an addition of O to CS or S to CO (equation 10) with a third possibility of C, S, O atoms combining first to make either CS or CO first and then adding O or S, respectively, to synthesize OCS.…”

“…Details of the experimental chamber can be found in our very recent publication. 8 Chemically inert and mid-Infrared (IR) transparent Zinc Selenide (ZnSe) window was used as the substrate, which upon cooling down to 85 K is an analogue of a dust surface for icy mantles.…”

Infrared spectra and chemical abundance of methyl propionate in icy astrochemical conditions

“…Experiments were carried out in the low temperature astrochemistry apparatus housed in the Physical Research Laboratory (PRL); a detailed description of the experimental apparatus can be found elsewhere (Sivaraman, et al 2014). Upon achieving UltraHigh Vacuum (UHV) of the order of 10 -9 mbar and low temperature (85 K) at the zinc selenide (ZnSe) substrate, methyl propionate molecules in the gas phase, extracted from the liquid sample that was freeze pump thawed three times to eliminate any impurity, was let into the chamber to form icy layers of methyl propionate at 85 K. Sample deposition was monitored by Fourier Transform InfraRed (FTIR) spectrometer operated in the mid-infrared wavelength, 4000 cm -1 -400 cm -1 .…”

“…Methyl acetate dissociation carried out experimentally simulating the interstellar cold conditions also pointed out the formation of alcohol, methyl alcohol (CH3OH), along with other products to form from acetate (Sivaraman et al 2014). In Interstellar chemistry, methyl alcohol is among the most dominant molecule influencing various chemical reactions that takes place on cold dust grains.…”