AstroSurf: A Network in Laboratory Astrophysics

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AstroSurf A Network in Laboratory Astrophysics

• An Overview of Activity in Laboratory Surface
  Science in the UK and Europe as applied to
  Astronomy and Astrophysics

Martin McCoustra
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Cosmic Surface and Solid State Science
Diffuse ISM
Dense Clouds
Star and Planet Formation (Conditions for
Evolution of Life and Sustaining it)
Stellar Evolution and Death
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Cosmic Surface and Solid State Science
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Cosmic Surface and Solid State Science
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Cosmic Surface and Solid State Science

• Dust grains are believed to have several crucial
  roles in the clouds
• Assist in the formation of small hydrogen-rich
  molecules including H2, H2O, CH4, NH3, ... some
  of which will be trapped as icy mantles on the
  grains
• Some molecules including CO, N2, ... can condense
  on the grains from the gas phase
• The icy grain mantle acts as a reservoir of
  molecules used to radiatively cool collapsing
  clouds as they warm
• Reactions induced by UV photons and cosmic rays
  in these icy mantles can create complex organic
  molecules
• Icy grains are the precursors to comets and
  planets

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Cosmic Surface and Solid State Science

• Molecular Identification
• Good database of surface and solid state spectra
  in the mid-IR (2 20 ?m) but effects of
  environment on spectroscopy need to be better
  understood both experimentally and theoretically
• Almost no relevant data in the region beyond 20
  ?m to support observational work in the far-IR
  and beyond with the exception of some work on
  silicate minerals
• Some relevant data in the UV, VUV and XUV regions
  important for understanding surface and solid
  state photoprocesses, but we need quantification

The bottom line is that our database of spectra
needs further fleshing out through a combination
of experiment and theory
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Cosmic Surface and Solid State Science

• Molecular Formation Rates
• H2 is relatively well studied, but there is still
  some disagreement
• For the heavier molecules (H2O, NH3 etc.) almost
  nothing is known but experiments on water
  formation are now underway in Europe and Japan
• Chemical processing on grains through free
  radical and thermal ion interactions with
  surfaces is on the horizon especially in relation
  to the role of polymerisation of small carbon
  species on grains in forming carbonaceous
  materials
• Solid state synthesis in icy matrices using
  photons and low energy secondary electrons from
  cosmic ray passage is increasingly understood but
  UHV studies are essential to fully characterise
  the dynamics and rates of these thin film
  processes
• Synthesis during impacts is an unopened book

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Cosmic Surface and Solid State Science

• Mantle Desorption and Grain Erosion Processes
• Thermal desorption is increasingly well
  understood
• Cosmic ray sputtering is well understood
• Photon and secondary (low energy) electron
  stimulated processes are poorly understood, but
  UHV tools are increasingly being applied
• Role of grain erosion in the carbon cycle in
  linking large carbon molecules and carbonaceous
  grains to small carbon molecules needs exploring
• Grain-Grain collisions and mantle disruption is
  still largely an unexplored territory

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Laboratory Surface Astrophysics in the UK

• Substantial relevant activity in both
  experimental and theoretical aspects of surface
  and solid state science
• Experiment
• Three main centres (Heriot-Watt, UCL, Open
  University) with increasing activity in others
  (Belfast, Glasgow, Leeds, Newcastle, Strathclyde)
• Theory
• Activity increasing outside existing groups in
  UCL, Daresbury and Liverpool
• UK activity is co-ordinated, co-operative and
  collaborative

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Laboratory Surface Astrophysics in the UK

• AstroSurf Network (http//www.chem.ucl.ac.uk/astro
  surf/) acts as a focus for much of the UK
  activity
• Initially funded by EPSRC in 2005
• Support for meetings
• Annual Student Meeting with the RSC Astrophysical
  Chemistry Group
• Biannual AstroSurf Network Meeting (next at the
  end of June 2009 in London)
• Active website
• Brings together astronomers and
  chemists/physicists under a single banner to work
  more closely together on problems of common
  interest

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Laboratory Surface Astrophysics in the UK

• Strong international presence from the outset
• Clearly defined network goal of involving our
  colleagues across Europe and the rest of the
  world in our activities
• Current membership includes most of the leading
  players in this area in Europe
• Involved in developing laboratory astrophysics
  activities on existing and planned UK central
  facilities
• Central Laser Facility
• Alice (ERL-driven THz light source)
• NLS (UK Next Light Source Proposal)

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Laboratory Surface Astrophysics in Europe

• Long tradition of laboratory support for
  astronomy in a number of European observatories
• Catania, Leiden, Paris,
• Increasing interest from the surface science
  community across Europe building on UK success
• Some activities located on central facilities
• Soleil, Flash,
• Addressing European collaboration through
  Framework activities
• Proposed Integrated Training Network LASSIE
  (http//www.chem.ucl.ac.uk/astrosurf/lassie.html)

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Laboratory Surface Astrophysics in Europe

• Funding is a key issue
• Most existing experiments outside observatories
  funded at national level by appropriate Physical
  Sciences funding bodies e.g. EPSRC in the UK
• Some support from Central Facility operators
• Little or no support from astronomy and
  astrophysics funding bodies e.g. PPARC (STFC) in
  the UK
• Increasingly difficult to obtain funding by
  existing routes as these funders re-focus on
  science with deliverables having a direct
  societal impact
• Danger that some of the work necessary to support
  astronomy and astrophysics is viewed as stamp
  collecting

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Laboratory Surface Astrophysics in Europe

• Community welcomes the realisation that our work,
  and that of our colleagues working in the gas
  phase, is an integral part of astronomy and
  astrophysics
• We would very strongly support moves to secure
  funding from appropriate sources for these
  crucial laboratory-based activities (both
  experimental and computational)
• There is a well-established suite of experiments
  across Europe addressing most of the key
  questions but efforts are limited by the lack of
  manpower (ESR and ER)
• Provision of manpower to support these
  experiments could come through support for
  existing (The Molecular Universe - molecular gas
  phase) or proposed (LASSIE - surface and solid
  state) research training networks