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4 th Annual LEIF Meeting, Belfast. Ion Irradiation of Astrophysical Ice Analogues. Anita Dawes. Introduction. Not much is known about the mechanisms involved in solid state chemistry in astrophysical environments. Over 120 molecular species have been detected in space - PowerPoint PPT Presentation
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Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
Ion Irradiation of Ion Irradiation of Astrophysical Ice Astrophysical Ice
AnaloguesAnalogues
4th Annual LEIF Meeting, Belfast
Anita DawesAnita Dawes
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
IntroductionIntroduction Not much is known about the mechanisms involved in Not much is known about the mechanisms involved in
solid state chemistry in astrophysical environments.solid state chemistry in astrophysical environments.
Over 120 molecular species have been detected Over 120 molecular species have been detected in spacein space Abundances and formation cannot be explained by gas Abundances and formation cannot be explained by gas
phase chemistryphase chemistry
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
2 3 4 5 6 7 8 9 10 11H2 C3 c-C3H C5 C5H C6H CH3C3N CH3C4H CH3C5N? HC9N
AlF C2H l-C3H C4H l-H2C4 CH2CHCN HCOOCH3 CH3CH2CN (CH3)2CO
AlCl C2O C3N C4Si C2H4 CH3C2H CH3COOH (CH3)2O NH2CH2COOH ? 12C2 C2S C3O l-C3H2 CH3CN HC5N C7H CH3CH2OH C6H6
CH CH2 C3S c-C3H2 CH3NC NH2CH3 H2C6 HC7N
CH+ HCN C2H2 CH2CN CH3OH HCOCH3 CH2OHCHO C8H 13+CN HCO CH2D
+ ? CH4 CH3SH c-C2H4O HC11N
CO HCO+ HCCN HC3N HC3NH+ CH2CHOH PAHs
CO+ HCS+ HCNH+ HC2NC HC2CHO C60C60++
CP HOC+ HNCO HCOOH NH2CHO
CSi H2O HNCS H2CHN C5N
HCl H2S HOCO+ H2C2O
KCl HNC H2CO H2NCN
NH HNO H2CN HNC3
NO MgCN H2CS SiH4
NS MgNC H3O+ H2COH+
NaCl N2H+ NH3
OH N2O SiC3
PN NaCNSO OCSSO+ SO2
SiN c-SiC2SiO CO2
SiS NH2
CS H3+
HF SiCNSHFeO AlNCAlNC
>120 Interstellar and Circumstellar Molecules>120 Interstellar and Circumstellar Molecules
National Radio Astronomy Observatory
Formic Acid
Acetic Acid
Glycolaldehyde
Benzene
Cyanopolyynes
Glycine ?
http://www.cv.nrao.edu/~awootten/allmols.html
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
Whittet et.al.A&A 315, L357-L360 (1996)Whittet et.al.A&A 315, L357-L360 (1996)
Ices in Space...Ices in Space...Gibb et.al. ApJ 536, 347-356 (2000)Gibb et.al. ApJ 536, 347-356 (2000)
W33A
SpeciesSpecies EliasElias1616
NGC 7538 NGC 7538 IRS 9IRS 9 GL 7009SGL 7009S W33AW33A GL 2136GL 2136 Sgr A*Sgr A* CometsComets
HH22OO 100 100 100 100 100 100 100
CO CO (total)(total) 25 16 15 8 2 <12 5-30CO CO (polar)(polar) 3 2 - 6 2 - -CO CO (nonpolar)(nonpolar) 22 14 - 2 - - -COCO22 (total)(total) 18 22 21 13 16 14 3-20
COCO22 (polar)(polar) 18 14 - 11 13 14 -
COCO22 (nonpolar)(nonpolar)
<1 8 - 2 3 <1 -
CHCH44 - 2 4 1.5 - 2 1
CHCH33OHOH <3 5 30 18 6 <4 0.3-5
HH22COCO - 4 3 6 3 <3 0.2-1
HCOOHHCOOH - 3 - 7 - 3 0.05OCSOCS <0.2 - 0.2 0.2 - - 0.5NHNH33 9 13 - 15 - 20-30 0.1-1.8
XCNXCN <0.5 1 1.5 3.5 0.3 - 0.01-0.4
Gibb et.al. ApJ 536, Gibb et.al. ApJ 536, 347-356 (2000)347-356 (2000)
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
PlanetSatellite
Ices
JupiterJupiter IoIo SO2, SO3, H2S?, H2O?
EuropaEuropa H2O, SO2, SH, CO2, CH, XCN, H2O2, H2SO4
GanymedGanymedee
H2O, SO2, SH, CO2, CH, XCN, O2, O3
CallistoCallisto H2O, SO2, SH, CO2, CH, XCN
SaturnSaturn MimasMimas H2O
EnceladusEnceladus H2O
TethysTethys H2O
DioneDione H2O, C, HC, O3
RheaRhea H2O, HC?, O3
HyperionHyperion H2O
IapetusIapetus H2O, C, HC, H2S?
PhoebePhoebe H2O
RingsRings H2O
UranusUranus MirandaMiranda H2O, NH3
ArielAriel H2O, OH?
UmbrielUmbriel H2O
TitaniaTitania H2O, C, HC, OH?
OberonOberon H2O, C, HC, OH?
NeptunNeptunee
TritonTriton N2, CH4, CO, CO2, H2O
PlutoPluto CharonCharon H2O, NH3, NH3 hydrate
N2, CH4, CO, H2O
KBO’sKBO’s H2O, HC-ices (CH4, CH3OH), HC, silicates
Ices in the outer Solar SystemIces in the outer Solar System
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
IntroductionIntroduction Not much is known about the mechanisms involved in Not much is known about the mechanisms involved in
solid state chemistry in astrophysical environments.solid state chemistry in astrophysical environments.
Over 120 molecular species have been detected Over 120 molecular species have been detected in spacein space Abundances and formation cannot be explained by gas Abundances and formation cannot be explained by gas
phase chemistryphase chemistry
Require laboratory data to understand the Require laboratory data to understand the mechanisms involved in condensed phase mechanisms involved in condensed phase molecular formation/destruction.molecular formation/destruction.
The nature of ices and their processing depends The nature of ices and their processing depends on the environment in which they are found...on the environment in which they are found...
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
Radiation EnvironmentsRadiation Environments The astrophysical ices can be The astrophysical ices can be broadlybroadly divided into 3 divided into 3
environments:environments: Icy grain mantles in the ISMIcy grain mantles in the ISM
Dense clouds: Dense clouds: Lyman-Lyman-, cosmic rays, cosmic rays Cold diffuse clouds: Cold diffuse clouds: UV dominatedUV dominated
Cometary ices Cometary ices Oort cloud: Oort cloud: cosmic ray dominatedcosmic ray dominated
Icy solar system bodiesIcy solar system bodies e.g. Mars polar caps: e.g. Mars polar caps: solar wind, solar UVsolar wind, solar UV Galilean satellites: Galilean satellites: magnetospheric ions (dominant) & solar magnetospheric ions (dominant) & solar
wind – wind – OO++, O, O2+2+, O, O3+3+, O, O4+4+, O, O6+6+, , SS++, S, S2+2+, S, S3+3+, S, S4+4+, S, S5+5+, S, S22++, SO, SO22
++, , NaNa++, K, K2+2+, C, C6+6+, H, H22OO++, H, H33OO++, OH, OH++, H, H++, He, He++, H, H22
++ and H and H33++
The ices can be physically characterised by the:The ices can be physically characterised by the: Thickness, temperature & compositionThickness, temperature & composition Energy, flux & type of processing radiationEnergy, flux & type of processing radiation
In our laboratory regime:In our laboratory regime: Ices are already present, i.e. not concerned with ice Ices are already present, i.e. not concerned with ice
accretion / formation accretion / formation thick ice layers (to ignore the effect of the substrate)thick ice layers (to ignore the effect of the substrate) Ion, photon and electron irradiationIon, photon and electron irradiation
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
To pumping station
Electrical feed-through Rotary feed-
through
Detectors (Spectroscopy):UV-VIS / FTIR spectrometerPMT
Sources (Spectroscopy):UV-VIS / FTIR spectrometerSynchrotron
Liquid Helium / Liquid Nitrogen Cryostat
Resistive heaterRhodium-iron RTD
CaF2 substrateCopper sample mount
Ion gauge
50.15
Liquid nitrogen exhaust
Cryogen inlet via transfer line
Temperature controller
HV (UHV) chamber:HV (UHV) chamber: P~10P~10-7-7-10-10-10-10 mbar mbar
CaFCaF22 substrate for substrate for transmission spectroscopytransmission spectroscopy
120 nm – 10 120 nm – 10 mm Temperature:Temperature:
LN2 / LHe cryostatLN2 / LHe cryostat >30 K>30 K Rh-Fe sensorRh-Fe sensor Resistive coax. HeaterResistive coax. Heater
4 ports4 ports Sample depositionSample deposition SpectroscopySpectroscopy IrradiationIrradiation
Transmission spectra Transmission spectra recorded vs. wavelength / recorded vs. wavelength / frequencyfrequency
Portable ApparatusPortable Apparatus
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
Sample PreparationSample Preparation
• Ice layers are vapour deposited directly onto a cold substrate.
• The gases are prepared in a reservoir prior to dosing
• Pure gases or mixtures
• Sample thickness is determined from the pressure of gas deposited.
• Ice thickness is calibrated by measuring the absorption through the sample (column densities) or analysing interference fringes
TurboPump
To rotary Feed-through
To RotaryPump for roughing
Liquid sample Gas from
Lecture bottle
UHV
Gas reservoir
Baratron
ON/OFF Valve
PrecisionLeak Valve
ON/OFF valve
Needle valve
Gas regulator
Pirani Gauge
~10m thick CO2 ice (left)
~3 m thick H2O ice (right)
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
RadiationRadiation SourceSource EnergyEnergy
PhotonPhoton
Hydrogen LampHydrogen Lamp(on-site not yet in operation)(on-site not yet in operation)
Synchrotron RadiationSynchrotron Radiation(Daresbury SRS & (Daresbury SRS & ÅÅrhus ASTRID)rhus ASTRID)
Limited WavelengthsLimited Wavelengths(Lyman-(Lyman- dominated) dominated)
Tuneable: (3-10eV)Tuneable: (3-10eV)(grating monochromator)(grating monochromator)
ElectronElectron Electron Gun Electron Gun (on-site not yet in operation)(on-site not yet in operation)
< 20 eV< 20 eV
Ion:Ion:
singly and singly and multiply chargedmultiply charged
Van de Graff AcceleratorVan de Graff Accelerator (QUB)(QUB)
ECR Ion sourceECR Ion source (QUB)(QUB)
keV – MeVkeV – MeV
Low keVLow keV
Sample IrradiationSample Irradiation
1 hour of irradiation in the lab is equivalent to 1000 years 1 hour of irradiation in the lab is equivalent to 1000 years irradiation in space!irradiation in space!
Once deposited, the samples are irradiated with either photons, ions or Once deposited, the samples are irradiated with either photons, ions or electronselectrons
• The products may be probed at regular intervals by The products may be probed at regular intervals by
spspecectrtrososcocopypy• UV-UV-VVIISS & VUV & VUV : Electronic Structure: Electronic Structure• FTIR FTIR : Vibrational Structure: Vibrational Structure
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
What are we currently looking at?What are we currently looking at?
Study of HStudy of H22O, COO, CO22 and H and H22O:COO:CO22 ices ices These are two of the most abundant moleculesThese are two of the most abundant molecules Present in all astrophysical environments (grain mantles, Present in all astrophysical environments (grain mantles,
comets, Galilean satellites, Mars & Triton.comets, Galilean satellites, Mars & Triton.
Irradiation with ionsIrradiation with ions 100 keV H100 keV H++
Low energy (1-5 keV) Low energy (1-5 keV) singlysingly charged ions charged ions Low energy (1-5*q keV) Low energy (1-5*q keV) multiplymultiply charged ions charged ions implantation – implantation – reactivereactive ions: ions: CC++ on H on H22O and HO and H++ on CO on CO22
Irradiation with photonsIrradiation with photons Zero order Synchrotron radiationZero order Synchrotron radiation Discrete wavelengths (synchrotron grating monochromator)Discrete wavelengths (synchrotron grating monochromator)
Products we are looking for in HProducts we are looking for in H22O:COO:CO22 ices: ices: Carbonic acid (HCarbonic acid (H22COCO33)) CO, COCO, CO33, H, H22O:COO:CO22 complex, HCO, O complex, HCO, O33(?) and others (?)(?) and others (?)
FTIR spectraFTIR spectra
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
Irradiation of HIrradiation of H22O:COO:CO22 ice at 90 K with ice at 90 K with100 keV H100 keV H++
H2O
H2OH2O
CO2
13CO2
CO2
H2O:CO2
H2O
H2OH2O
CO2
13CO2
CO2
H2O:CO2
H2CO3
(2850) H2CO3
(2580)
CO(2140)
CO3
(2044)
H2CO3
(1703)
H2CO3
(1488)H2CO3
(1295)
After 1 hour irradiationAfter 1 hour irradiation
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
H2O
H2OH2O
CO2
13CO2
H2O:CO2
H2O
H2OH2O
CO2
13CO2
H2O:CO2
H2CO3
(2850) H2CO3
(2580)
CO(2140)
H2CO3
(1703)
H2CO3
(1488)H2CO3
(1295)NO CO3!
After 0.5 hour irradiationAfter 0.5 hour irradiation
Irradiation of HIrradiation of H22O:COO:CO22 ice at 50 K with ice at 50 K with5 keV H5 keV H++
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
Warm-up after Warm-up after HH++ Irradiation Irradiation of Hof H22O:COO:CO22 ice ice
50 K100 K120 K140 K
CO2
H2O
H2O
160 K
CO2
H2OH2O
H2O
CO
Crystalline
H2O
CO2
H2O180 K
CO2
H2OH2O
H2O
CO
200 K
H2O
H2O H2O
CO2
220 K
H2OCO2
Temp:
H2CO3
H2CO3
250 K
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
HH22COCO33 yield after irradiation with yield after irradiation with
HH++,, HeHe++,, OO++ andand NeNe++ (all at 5 keV)(all at 5 keV)
Yield depends on:Yield depends on: Ion range?Ion range? Reactive, Reactive,
unreactive ion?unreactive ion?
Low or no yield Low or no yield with multiply with multiply charged ions (Ncharged ions (N3+3+, , NN5+5+, N, N6+6+) – ) – not not shown hereshown here::
Lack of secondary Lack of secondary electrons?electrons?
Small penetration Small penetration depth?depth?
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
The CO profileThe CO profile
The 2152 cmThe 2152 cm-1-1 CO CO feature possible feature possible origin:origin:
formation at formation at different sites in different sites in the ice matrix the ice matrix (substitutional / (substitutional / interstitial)interstitial)
(Sandford et.al. ApJ 329, 498-(Sandford et.al. ApJ 329, 498-510, 1998)510, 1998)
CO diffusion into CO diffusion into unirradiated ice unirradiated ice and interaction and interaction with the dangling with the dangling OH bondsOH bonds
(Palumbo, J Phys Chem A, (Palumbo, J Phys Chem A, 101, 4298-4301, 1997)101, 4298-4301, 1997)
(Sandford et.al. ApJ 329, 498-510, 1998)
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
0.012
0.017
0.022
0.027
0.032
0.037
0.042
0.047
212021302140215021602170
Wavenumber (cm-1)
ABS
0.012
0.017
0.022
0.027
0.032
0.037
0.042
0.047
212021302140215021602170
0.012
0.017
0.022
0.027
0.032
0.037
0.042
0.047
212021302140215021602170
0.012
0.017
0.022
0.027
0.032
0.037
0.042
0.047
212021302140215021602170
0.012
0.017
0.022
0.027
0.032
0.037
0.042
0.047
212021302140215021602170
CO formation by irradiation of HCO formation by irradiation of H22O:COO:CO22=1 with different =1 with different ions (5*q keV) at 50Kions (5*q keV) at 50K
The 2152 cmThe 2152 cm-1-1 CO CO feature :feature :
Increases with mass Increases with mass of ionof ion
interstitial ?interstitial ?
Increases with Increases with decreasing decreasing penetration depth of penetration depth of ionion
diffusion ?diffusion ? Repeated Repeated
experiment at ~ 100 experiment at ~ 100 K with heavier K with heavier ions.....ions..... No 2152 No 2152 feature!feature!
diffusion ?diffusion ?
(CO partially sublimes >27 (CO partially sublimes >27 K)K)
CO
H+
He+
N3+
O+
Ne+
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
97.8
97.9
98.0
98.1
98.2
98.3
98.4
98.5
98.6
98.7
98.8
21202125213021352140214521502155216021652170
Wavenmber (cm-1)
%Tra
nsm
issi
on
Irradiation of pure HIrradiation of pure H22O with 2 keV CO with 2 keV C++
Irradiation time 00:00
97.8
97.9
98.0
98.1
98.2
98.3
98.4
98.5
98.6
98.7
98.8
21202125213021352140214521502155216021652170
Wavenmber (cm-1)
%Tra
nsm
issi
on
00:15
97.8
97.9
98.0
98.1
98.2
98.3
98.4
98.5
98.6
98.7
98.8
21202125213021352140214521502155216021652170
Wavenmber (cm-1)
%Tra
nsm
issi
on
00:30
97.8
97.9
98.0
98.1
98.2
98.3
98.4
98.5
98.6
98.7
98.8
21202125213021352140214521502155216021652170
Wavenmber (cm-1)
%Tra
nsm
issi
on
00:45
97.8
97.9
98.0
98.1
98.2
98.3
98.4
98.5
98.6
98.7
98.8
21202125213021352140214521502155216021652170
Wavenmber (cm-1)
%Tra
nsm
issi
on
01:00
97.8
97.9
98.0
98.1
98.2
98.3
98.4
98.5
98.6
98.7
98.8
21202125213021352140214521502155216021652170
Wavenmber (cm-1)
%Tra
nsm
issi
on
01:15
97.8
97.9
98.0
98.1
98.2
98.3
98.4
98.5
98.6
98.7
98.8
21202125213021352140214521502155216021652170
Wavenmber (cm-1)
%Tra
nsm
issi
on
COApolar Component Polar Component
2152 cm-1 feature
01:15
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
Summary of Results... Summary of Results... More questions...?More questions...?
CO, COCO, CO33 and H and H22COCO33 were seen after irradiation of H were seen after irradiation of H22O:COO:CO22 with 100 keV H with 100 keV H++
But...But...
No HNo H22COCO33 seen with highly charged ions (or signal too weak?) seen with highly charged ions (or signal too weak?) Low penetration depth?Low penetration depth? Lack of secondary electrons?Lack of secondary electrons? PE vs KE effect?PE vs KE effect?
No CONo CO33 seen after irradiation of H seen after irradiation of H22O:COO:CO33 with low (<5*q keV) with low (<5*q keV) energy/multiply charged ions!energy/multiply charged ions!
KE vs PE effect?KE vs PE effect? Nuclear vs electronic stopping?Nuclear vs electronic stopping?
2152 cm2152 cm-1-1 feature of CO was seen in H feature of CO was seen in H22O:COO:CO22 irradiated ice with heavier irradiated ice with heavier ions at T<60 Kions at T<60 K
But...But...
2152 cm2152 cm-1-1 feature was not seen in H feature was not seen in H22O:COO:CO22 irradiated ice with any ion at T > irradiated ice with any ion at T > 90 K90 K Many more...Many more...
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
To do... To do... Search for Answers!Search for Answers!
Changing the beam...Changing the beam... Singly vs. multiply charged ionsSingly vs. multiply charged ions
kinetic vs. potential effects?kinetic vs. potential effects? Secondary electrons...Secondary electrons...
Different energiesDifferent energies nuclear vs. electronic stopping nuclear vs. electronic stopping
effect of ions (latter dominates effect of ions (latter dominates as energy increases)as energy increases)
Different ions Different ions Effect of ion Effect of ion
mass/momentum/velocitymass/momentum/velocity Reactive / unreactive ionsReactive / unreactive ions Implantation – chemical vs. Implantation – chemical vs.
physical effectsphysical effects Low energy electron irradiationLow energy electron irradiation
Secondary electron effect Secondary electron effect following ion irradiationfollowing ion irradiation
Ion vs. Photon irradiationIon vs. Photon irradiation Systematic comparisonSystematic comparison
Changing the sample...Changing the sample... TemperatureTemperature
Diffusion (e.g. CO)Diffusion (e.g. CO) Activation energyActivation energy Crystalline vs. amorphous iceCrystalline vs. amorphous ice Get down to 10K!!Get down to 10K!!
CompositionComposition Isotopic substitution to identify Isotopic substitution to identify
reaction pathwaysreaction pathways Ratio of componentsRatio of components
StructureStructure PorosityPorosity Crystalline vs. amorphous iceCrystalline vs. amorphous ice
ThicknessThickness Ion / photon penetration depthIon / photon penetration depth ImplantationImplantation
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
GeneralGeneral SummarySummaryGeneralGeneral SummarySummary More experimental work is needed to fully understand the mechanisms More experimental work is needed to fully understand the mechanisms
involved in synthesis of molecules under astrophysical environments...involved in synthesis of molecules under astrophysical environments...
The design of the new apparatus allows flexibility to perform a wide The design of the new apparatus allows flexibility to perform a wide variety of experiments, using different sources to irradiate samples and variety of experiments, using different sources to irradiate samples and implement a variety of spectroscopic techniques using different implement a variety of spectroscopic techniques using different instruments.instruments. Ion accelerators – Belfast (singly & multiply charged ions)Ion accelerators – Belfast (singly & multiply charged ions) Synchrotron Sources – Synchrotron Sources – ÅÅrhus & Daresbury (irradiation & rhus & Daresbury (irradiation &
spectroscopy... Circular dichroism)spectroscopy... Circular dichroism)
Electron and photon sources Electron and photon sources
These experiments will enable us to better understand the processes These experiments will enable us to better understand the processes behind chemical processing if ices in the ISM and the planets, satellites, behind chemical processing if ices in the ISM and the planets, satellites, comets and meteorites within our solar system.comets and meteorites within our solar system. (The apparatus can also (The apparatus can also be adapted to study atmospheric ices e.g. polar stratospheric clouds)be adapted to study atmospheric ices e.g. polar stratospheric clouds)
A systematic experimental approach is required to identify reaction A systematic experimental approach is required to identify reaction pathways and intermediates whilst pinning down the different variables pathways and intermediates whilst pinning down the different variables (both sample and irradiation parameters).(both sample and irradiation parameters).
Many more experiments to come...Many more experiments to come...
Sun 29Sun 29thth June 2003 June 2003 [email protected]@ucl.ac.uk
AcknowledgementsAcknowledgements
Nigel MasonNigel Mason
Stephen BrottonStephen BrottonMike DavisMike DavisPhilip HoltomPhilip Holtom
Bob McCulloughBob McCulloughand Ian Williams and Ian Williams (QUB)(QUB)
Roland TrasslRoland Trassl(Geissen University)(Geissen University)
SSøøren Vrønning ren Vrønning HoffmannHoffmann(ASTRID, (ASTRID, Århus)Århus)