Molecular Synthesis in Astrophysical Ices
Lead Research Organisation:
The Open University
Department Name: Physical Sciences
Abstract
The continuous cycle of star formation, evolution and death is driven by a complex interplay between interstellar gas, dust and radiation [1]. The interstellar medium (ISM) is a rich chemical factory, with over 170 molecular species identified to date [2], mostly observed in star-forming regions. Star formation begins in dense molecular clouds, where cold (~10 K) interstellar dust provides the surfaces for atoms and molecules to "freeze-out", forming icy mantles. These icy mantles are the largest molecular reservoirs in the ISM, where chemical reactions, driven by both non-thermal and thermal processes, produce more complex molecules that are subsequently released into the gas phase [3]. At the OU Astrochemistry laboratories, we investigate the physical and chemical properties of astrochemical ices in a controlled laboratory environment using ultra-high vacuum chambers and cryogenically cooled substrates to grow interstellar ice analogues [4-6]. The ices are characterised in situ, using Fourier-Transform Infrared Spectroscopy (FTIR) on-site or Vacuum Ultraviolet spectroscopy via access to synchrotron facilities (ASTRID2 in Aarhus, Denmark; and, in partnership with Dr Bhala Sivaraman at PRL in India, the Taiwan Synchrotron facility). The FTIR and VUV spectra are highly sensitive to the ice morphology and the interaction between the molecular species in the ice, and are also used to monitor any changes as a result of thermal (controlled heating) or non-thermal (UV, electron or ion irradiation) processing. Additionally, mass spectroscopy is used to monitor the species that are released into the gas phase (desorption and sputtering) during processing. Recent advances include the development of more realistic dust grain mimics using nanofabrication techniques to fashion carbonaceous and silicate microstructures to act as a grain template for ice deposition. We are also exploring use of ultrasonic levitation of dust grains as a method for studying astrochemistry on isolated grains.
Organisations
People |
ORCID iD |
Nigel Mason (Primary Supervisor) | |
Rachel James (Student) |
Publications
Ioppolo S
(2021)
Vacuum ultraviolet photoabsorption spectroscopy of space-related ices: formation and destruction of solid carbonic acid upon 1 keV electron irradiation
in Astronomy & Astrophysics
Ioppolo S
(2020)
Vacuum ultraviolet photoabsorption spectroscopy of space-related ices: 1 keV electron irradiation of nitrogen- and oxygen-rich ices
in Astronomy & Astrophysics
Cassidy A
(2020)
Crystallites and Electric Fields in Solid Ammonia.
in ChemistryOpen
Cassidy A
(2020)
Cover Feature: Crystallites and Electric Fields in Solid Ammonia (ChemistryOpen 10/2020)
in ChemistryOpen
Cassidy A
(2019)
The optical absorption spectra of spontaneously electrical solids: the case of nitrous oxide.
in Physical chemistry chemical physics : PCCP
James RL
(2020)
Systematic investigation of CO2 : NH3 ice mixtures using mid-IR and VUV spectroscopy - part 1: thermal processing.
in RSC advances
James RL
(2019)
VUV spectroscopy of an electron irradiated benzene : carbon dioxide interstellar ice analogue.
in RSC advances
Studentship Projects
Project Reference | Relationship | Related To | Start | End | Student Name |
---|---|---|---|---|---|
ST/N50421X/1 | 30/09/2015 | 30/03/2021 | |||
1810630 | Studentship | ST/N50421X/1 | 31/07/2016 | 31/10/2019 | Rachel James |
Description | OU Astronomy Club |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Other audiences |
Results and Impact | Talk given to an amateur astronomy group about astrochemistry which generated questions and discussion afterwards. |
Year(s) Of Engagement Activity | 2020 |