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1. Low-temperature optical constants of amorphous silicate dust analogues

Author

Demyk, K., Gromov, V., Meny, C., Ysard, N., Paradis, D., Jones, A. P., Petitprez, D., Hubert, P., Leroux, H., Nayral, C., and Delpech, F.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

Cosmic dust models are key ingredients in advancing our understanding of astronomical environments as diverse as interstellar clouds in galaxies, circumstellar envelopes around evolved and young stars, and protoplanetary disks. Such models consist of several dust populations, each with different compositions and size distributions. They may also consider different grain shapes, although most models assume spherical grains. All include a component of silicate dust. The absorption and emission properties of these dust components are calculated from the optical constants of each dust material which have various experimental, phenomenological, and theoretical origins depending on the model. We aim to provide the community with new sets of optical constants for amorphous silicate dust analogues at low temperatures. The analogues consist of four Mg-rich silicate samples of stoichiometry ranging from enstatite to olivine, and of eight samples of Mg and Fe rich silicates with a pyroxene stoichiometry and differing magnesium and iron content. We calculated the optical constants from transmission measurements using the Kramers-Kronig relations, assuming that the grains are small compared to the wavelength and prolate in shape with axis ratios of 1.5 and 2 for the Mg and Fe rich samples, respectively. New optical constants for silicate dust analogues were calculated over the wavelength range from 5 to 800-1000 microns, depending on the sample, and at temperatures of 10, 30, 100, 200, and 300 K.We determined the uncertainties on the derived optical constants based on the assumptions used to calculate them. To facilitate the use of these data in cosmic dust models, we provide optical constants extrapolated outside the measured spectral range into the UV-NIR and mm-cm wavelength ranges, as well as formulae that can be used to interpolate them at any temperature in the range 10 - 300 K.

Published
2022
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2. Sample return of primitive matter from the outer Solar System

Author

Vernazza, P., Beck, P., Ruesch, O., Bischoff, A., Bonal, L., Brennecka, G., Brunetto, R., Busemann, H., Carter, J., Carli, C., Cartier, C., Ciarniello, M., Debaille, V., Delsanti, A., D’Hendecourt, L., Füri, E., Groussin, O., Guilbert-Lepoutre, A., Helbert, J., Hoppe, P., Jehin, E., Jorda, L., King, A., Kleine, T., Lamy, P., Lasue, J., Le Guillou, C., Leroux, H., Leya, I., Magna, T., Marrocchi, Y., Morlok, A., Mousis, O., Palomba, E., Piani, L., Quirico, E., Remusat, L., Roskosz, M., Rubin, M., Russell, S., Schönbächler, M., Thomas, N., Villeneuve, J., Vinogradoff, V., Wurz, P., and Zanda, B.

Published
2022
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4. Low-temperature MIR to submillimeter mass absorption coefficient of interstellar dust analogues II: Mg and Fe-rich amorphous silicates

Author

Demyk, K., Meny, C., Leroux, H., Depecker, C, Brubach, J. -B., Roy, P., Nayral, C., and Ojo, W. -S.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

To model the cold dust emission observed in the diffuse interstellar medium, in dense molecular clouds or in cold clumps that could eventually form new stars, it is mandatory to know the physical and spectroscopic properties of this dust and to understand its emission. This work is a continuation of previous studies aiming at providing astronomers with spectroscopic data of realistic cosmic dust analogues for the interpretation of observations. Ferromagnesium amorphous silicate dust analogues were produced with a mean composition close to $\mathrm{Mg_{1-x}Fe_{x}SiO_3}$ with x = 0.1, 0.2, 0.3, 0.4. Part of each sample was annealed at 500$^{\circ}$C for two hours in a reducing atmosphere to modify the oxidation state of iron. We have measured the mass absorption coefficient (MAC) of these ferromagnesium amorphous silicate dust analogues in the spectral domain 30 - 1000 $\mu$m for grain temperature in the range 10 - 300 K and at room temperature in the 5 - 40 $\mu$m range. The MAC of ferromagnesium samples behaves in the same way as the MAC of pure Mg-rich amorphous silicate samples. In the 30 - 300 K range, the MAC increases with increasing grain temperature whereas in the range 10 - 30 K, we do not see any change of the MAC. The MAC cannot be described by a single power law in ${\lambda}^{-\beta}$. The MAC of all the samples is much higher than the MAC calculated by dust models. The complex behavior of the MAC of amorphous silicates with wavelength and temperature is observed whatever the exact silicate composition (Mg vs. Fe amount). It is a universal characteristic of amorphous materials, and therefore of amorphous cosmic silicates, that should be taken into account in astronomical modeling. The enhanced MAC of the measured samples compared to the MAC calculated for cosmic dust model implies that dust masses are overestimated by the models.

Published
2017
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5. Low temperature MIR to submillimeter mass absorption coefficient of interstellar dust analogues I: Mg-rich glassy silicates

Author

Demyk, K., Meny, C., Lu, X. -H., Papatheodorou, G., Toplis, M. J., Leroux, H., Depecker, C., Brubach, J. -B., Roy, P., Nayral, C., Ojo, W. -S., Delpech, F., Paradis, D., and Gromov, V.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

A wealth of data from the Herschel and Planck satellites and now from ALMA, revealing cold dust thermal emission, is available for astronomical environments ranging from interstellar clouds, cold clumps, circumstellar envelops, and protoplanetary disks. The interpretation of these observations relies on the understanding and modeling of cold dust emission and on the knowledge of the dust optical properties. The aim of this work is to provide astronomers with a set of spectroscopic data of realistic interstellar dust analogues that can be used to interpret the observations. Glassy silicates of mean composition (1-x)MgO - xSiO2 with x = 0.35, 0.40 and 0.50 were synthesized. The mass absorption coefficient (MAC) of the samples was measured in the spectral domain 30 - 1000 $\mu$m for grain temperature in the range 300 K - 10 K and at room temperature in the 5 - 40 $\mu$m domain. We find that the MAC of all samples varies with the grains temperature. In the FIR/submm, and above 30K, the MAC value at a given wavelength increases with the temperature as thermally activated absorption processes appear. The studied materials exhibit different and complex behaviors at long wavelengths (lambda $\geq$ 200 to 700 $\mu$m depending on the samples) and the MAC cannot be approximated by a single power law in ${\lambda}^{-\beta}$. These behaviors are attributed to the amorphous nature of dust and to the amount and nature of the defects within this amorphous structure. Above 20 $\mu$m, the measured MAC are much higher than the MAC calculated from interstellar silicate dust models indicating that the analogues measured in this study are more emissive than the silicates in cosmic dust models. This has important astrophysical implications because masses are overestimated by the models. Moreover, constraints on elemental abundance of heavy elements in cosmic dust models are relaxed

Published
2017
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10. Low temperature FIR and submm mass absorption coefficient of interstellar silicate dust analogues

Author

Coupeaud, A., Demyk, K., Meny, C., Nayral, C., Delpech, F., Leroux, H., Depecker, C., Creff, G., Brubach, J. B., and Roy, P.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Cold dust grains emission in the FIR/submm is usually expressed as a modified black body law in which the dust mass absorption coefficient (MAC), is described with a temperature- and wavelength-independent emissivity spectral index, beta. However, numerous data from space and balloon-born missions and recently from Herschel and Planck show that dust emission is not well understood, as revealed by the observed anti-correlation of beta with the grain temperature. In order to give astronomers the necessary data to interpret FIR/submm observations, we synthesised analogues of interstellar amorphous and crystalline silicate grains, rich in Mg and Ca, and having stiochiometry of olivine and pyroxene and measured their MAC, in the 100-1000/1500 \mum range for grain temperatures varying from 300 to 10 K. We find that the grain MAC decreases when the grain temperature decreases and that the local spectral index, beta, defined as the slope of the MAC curve, is anti-correlated with the grain temperature. These variations, which are not observed in the crystallised samples, are related to the amorphous nature of the samples. In addition, the spectral shape of the MAC is complex: at short wavelengths (lambda < 500/700 \mum), beta is in the range 1.6 - 2.1 for all grain temperature and grain composition whereas at longer wavelengths (lambda > 500/700 \mum), beta < 2 for samples with a pyroxene stoichiometry and beta > 2 for samples with an olivine stoichiometry. Hence, the simplifying asymptotic expression based on a single temperature- and wavelength-independent spectral index used by astronomers is not appropriate to describe the dust MAC and thus the dust emission, and may induce significant errors on the derived parameters such as the dust mass and the dust physical and chemical properties. Instead, dust emission models should use the dust MAC as a function of wavelength and temperature.

Published
2011
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11. Pervasive shock melting at >65 GPa in a Martian basalt, the shergottite Northwest Africa 14672.

Author

Hewins, R. H., Leroux, H., Jacob, D., Pont, S., Beyssac, O., Malarewicz, V., Lorand, J.‐P., Zanetta, P.‐M., and Zanda, B.

Subjects
*PLAGIOCLASE, *MELTING, *BASALT, *OLIVINE, *PYROXENE, *ILMENITE
Abstract

Shergottites have provided abundant information on the volcanic and impact history of Mars. Northwest Africa (NWA) 14672 contributes to both of these aspects. It is a vesicular ophitic depleted olivine–phyric shergottite, with average plagioclase An61Ab39Or0.2. It is highly ferroan, with pigeonite compositions En49‐25Fs41‐61Wo10‐14 like those of basaltic shergottites, for example, NWA 12335. Olivine (Fo53‐15) has discrete ferroan overgrowths, more ferroan when in contact with plagioclase than when enclosed by pyroxene. The pyroxene (a continuum of augite, subcalcic augite, and pigeonite) is patchy, with ragged "cores" enveloped or invaded by ferroan pyroxene. Magma mixing may be responsible for capture of olivine and formation of pyroxene mantles. The plagioclase is maskelynite‐like in appearance, but the original laths were (congruently) melted and the melt partly crystallized as fine dendrites. Most of the 14% vesicles occur within plagioclase. Olivine, pyroxene, and ilmenite occur in part as fine aggregates crystallized after congruent melting with limited subsequent liquid mixing. There are two fine‐grained melt components, barred plagioclase with interstitial Fe‐bearing phases, and glass with olivine dendrites, derived by melting of mainly plagioclase and mainly pyroxene, respectively. Rare silica particles contain coesite and/or quartz, and silica glass. The rock has experienced >50% melting, compatible with peak pressure >~65 GPa. It is the most highly shocked shergottite so far, at shock stage S6/7. It may belong to the group of depleted shergottites ejected at ~1 Myr from Tooting Crater. [ABSTRACT FROM AUTHOR]

Published
2024
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13. E-flows for the Limpopo River Basin: present ecological state - drivers of ecosystem change

Author

O'Brien, G., primary, Dickens, C., additional, Stassen, R., additional, Erasmus, H., additional, Herselman, S., additional, van der Waal, B., additional, Wepener, V., additional, Pearson, H., additional, LeRoux, H., additional, Villholth, K., additional, Ebrahim, G., additional, Magombeyi, M., additional, Riddell, E., additional, and Petersen, R., additional

Published
2022
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15. The origin of GEMS in IDPs as deduced from microstructural evolution of amorphous silicates with annealing

Author

Davoisne, C., Djouadi, Z., Leroux, H., d'Hendecourt, L., Jones, A., and Deboffle, D.

Subjects
Astrophysics
Abstract

We present laboratory studies of the micro-structural evolution of an amorphous ferro-magnesian silicate, of olivine composition, following thermal annealing under vacuum. Annealing under vacuum was performed at temperatures ranging from 870 to 1020 K. After annealing spheroidal metallic nano-particles (2-50 nm) are found within the silicate films. We interpret this microstructure in terms of a reduction of the initial amorphous silicate FeO component, because of the carbon-rich partial pressure in the furnace due to pumping mechanism. Annealing in a controlled oxygen-rich atmosphere confirms this interpretation. The observed microstructures closely resemble those of the GEMS (Glass with Embedded Metal and Sulphides) found in chondritic IDPs (Interplanetary Dust Particles). Since IDPs contain abundant carbonaceous matter, a solid-state reduction reaction may have occurred during heating in the hot inner regions of the proto-solar disc. Related to this, the presence of forsterite grains grown from the amorphous precursor material clearly demonstrates that condensation from gaseous species is not required to explain the occurrence of forsterite around young protostars and in comets. Forsterite grains in these environments can be formed directly in the solid phase by thermal annealing of amorphous ferro-magnesian silicates under reducing conditions., Comment: 4 pages, 2 figures. Accepted for publication A&A Letter to the Editor

Published
2006
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19. PERVASIVE SHOCK-MELTING AT >65 GPa IN A MARTIAN BASALT, THE SHERGOTTITE NORTHWEST AFRICA 14672

Author

Hewins, Roger, Leroux, H., Jacob, D., Pont, S., Beyssac, O., Malarewicz, V., Lorand, J.-P., Zanetta, P. -M., Zanda, B., Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), and University of Arizona

Subjects
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars, impact melting, meteorites
Abstract

International audience; Shergottites have provided abundant information on the volcanic and impact history of Mars. Northwest Africa (NWA) 14672 contributes to both of these aspects. It is a vesicular ophitic depleted olivine-phyric shergottite, with average plagioclase An61Ab39Or0.2. It is highly ferroan, with pigeonite compositions En49-25Fs41-61Wo10-14 like those of basaltic shergottites, e.g. NWA 12335. Olivine (Fo53-15) has discrete ferroan overgrowths, more ferroan when in contact with plagioclase than when enclosed by pyroxene. The pyroxene (a continuum of augite, subcalcic augite, and pigeonite) is patchy, with ragged ‘cores’ enveloped or invaded by ferroan pyroxene. Magma mixing may be responsible for capture of olivine and formation of pyroxene mantles. The plagioclase is maskelynite-like in appearance, but the original laths were (congruently) melted and the melt partly crystallized as fine dendrites. Most of the 14% vesicles occur within plagioclase. Olivine, pyroxene, and ilmenite occur in part as fine aggregates crystallized after congruent melting with limited subsequent liquid mixing. There are two fine-grained melt components, barred plagioclase with interstitial Fe-bearing phases, and glass with olivine dendrites, derived by melting of mainly plagioclase and mainly pyroxene, respectively. Rare silica particles contain coesite and/or quartz, and silica glass. The rock has experienced >50% melting, compatible with peak pressure >~65 GPa. It is the most highly shocked shergottite so far, at shock stage S6/7. It may belong to the group of depleted shergottites ejected at ~1 myr from Tooting Crater.

Published
2023

24. Analysis of morphological and physicochemical changes in space-weathered hydrated silicates by visible/IR spectroscopy and electron transmission microscopy

Author

Rubino, S., Leroux, H., Aleon-Toppani, A., Lantz, C., Baklouti, D., Djouadi, Z., Troadec, David, Borondics, F., Brunetto, R., Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Centrale de Micro Nano Fabrication - IEMN (CMNF - IEMN), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), We thank O. Mivumbi, D. Ledu, C.O. Bacri, and P. Benoit-Lamaitrie for help and technical support with SIDONIE and INGMAR. INGMAR is a joint IAS-CSNSM (Orsay, France) facility funded by the P2IO LabEx (ANR-10-LABX-0038) in the framework Investissements d'Avenir (ANR-11-IDEX-0003-01). Finally, we thank A. Fadel for help and technical support with the SEM acquisitions. This work has been funded by the ANR project CLASSY (Grant ANR-17-CE31-0004-02)., Renatech Network, CMNF, ANR-10-LABX-0038,P2IO,Physics of the 2 infinities and the origins(2010), ANR-11-IDEX-0003,IPS,Idex Paris-Saclay(2011), and ANR-17-CE31-0004,CLASSY,Composition des surfaces du Système Solaire de bas albédo(2017)

Subjects
[SPI]Engineering Sciences [physics]
Abstract

International audience

Published
2022

26. Author Correction: Asymmetric thinning of the cerebral cortex across the adult lifespan is accelerated in Alzheimer’s disease (Nature Communications, (2021), 12, 1, (721), 10.1038/s41467-021-21057-y)

Author

Roe, JM, Vidal-Piñeiro, D, Sørensen, Ø, Brandmaier, AM, Düzel, S, Gonzalez, HA, Kievit, RA, Knights, E, Kühn, S, Lindenberger, U, Mowinckel, AM, Nyberg, L, Park, DC, Pudas, S, Rundle, MM, Walhovd, KB, Fjell, AM, Westerhausen, R, Masters, CL, Bush, AI, Fowler, C, Darby, D, Pertile, K, Restrepo, C, Roberts, B, Robertson, J, Rumble, R, Ryan, T, Collins, S, Thai, C, Trounson, B, Lennon, K, Li, QX, Ugarte, FY, Volitakis, I, Vovos, M, Williams, R, Baker, J, Russell, A, Peretti, M, Milicic, L, Lim, L, Rodrigues, M, Taddei, K, Taddei, T, Hone, E, Lim, F, Fernandez, S, Rainey-Smith, S, Pedrini, S, Martins, R, Doecke, J, Bourgeat, P, Fripp, J, Gibson, S, Leroux, H, Hanson, D, Dore, V, Zhang, P, Burnham, S, Rowe, CC, Villemagne, VL, Yates, P, Pejoska, SB, Jones, G, Ames, D, Cyarto, E, Lautenschlager, N, Barnham, K, Cheng, L, Hill, A, Killeen, N, Maruff, P, Silbert, B, Brown, B, Sohrabi, H, Savage, G, Vacher, M, Roe, JM, Vidal-Piñeiro, D, Sørensen, Ø, Brandmaier, AM, Düzel, S, Gonzalez, HA, Kievit, RA, Knights, E, Kühn, S, Lindenberger, U, Mowinckel, AM, Nyberg, L, Park, DC, Pudas, S, Rundle, MM, Walhovd, KB, Fjell, AM, Westerhausen, R, Masters, CL, Bush, AI, Fowler, C, Darby, D, Pertile, K, Restrepo, C, Roberts, B, Robertson, J, Rumble, R, Ryan, T, Collins, S, Thai, C, Trounson, B, Lennon, K, Li, QX, Ugarte, FY, Volitakis, I, Vovos, M, Williams, R, Baker, J, Russell, A, Peretti, M, Milicic, L, Lim, L, Rodrigues, M, Taddei, K, Taddei, T, Hone, E, Lim, F, Fernandez, S, Rainey-Smith, S, Pedrini, S, Martins, R, Doecke, J, Bourgeat, P, Fripp, J, Gibson, S, Leroux, H, Hanson, D, Dore, V, Zhang, P, Burnham, S, Rowe, CC, Villemagne, VL, Yates, P, Pejoska, SB, Jones, G, Ames, D, Cyarto, E, Lautenschlager, N, Barnham, K, Cheng, L, Hill, A, Killeen, N, Maruff, P, Silbert, B, Brown, B, Sohrabi, H, Savage, G, and Vacher, M

Abstract

In this article the affiliation details for Ulman Lindenberger were incorrectly given as ‘Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany’ but should have been ‘Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany’, ‘Max Planck UCL Centre for Computational Psychiatry and Ageing Research, Berlin, Germany’. The original article has been corrected.

Published
2022

28. E-flows for the Limpopo River Basin: present ecological state - drivers of ecosystem change. Project report prepared by the International Water Management Institute (IWMI) for the United States Agency for International Development (USAID)

Author

O'Brien, G., Dickens, Chris, Stassen, R., Erasmus, H., Herselman, S., Van Der Waal, B., Wepener, V., Pearson, H., LeRoux, H., Villholth, Karen, Ebrahim, Girma, Magombeyi, Manuel, Riddell, E., and Petersen, R.

Subjects
Zimbabwe, River basins, Botswana, Agricultural Finance, Ecological factors, Hydraulics, Surface water, Geomorphology, Ecosystems, Environmental flows, South Africa, Water quality, Limpopo River Basin, Agribusiness, Environmental Economics and Policy, Hydrology, Groundwater, Mozambique
Abstract

Colombo, Sri Lanka: International Water Management Institute (IWMI) Washington, DC, USA: USAID

Published
2022
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29. E-flows for the Limpopo River Basin: present ecological state - ecological response to change. Project report prepared by the International Water Management Institute (IWMI) for the United States Agency for International Development (USAID)

Author

O'Brien, G., Dickens, Chris, Diedericks, G., Kaiser, A., Barendze, C., Pearson, H., LeRoux, H., MacKenzie, J., Gerber, S., Petersen, R., and Dlamini, V.

Subjects
Zimbabwe, River basins, Botswana, Macroinvertebrates, Ecological factors, Surface water, Environmental flows, South Africa, Fish, Water quality, Ecosystem services, Limpopo River Basin, Agribusiness, Environmental Economics and Policy, International Development, Riparian vegetation, Livelihoods, Groundwater, Mozambique
Abstract

Colombo, Sri Lanka: International Water Management Institute (IWMI) Washington, DC, USA: USAID

Published
2022
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30. A Conceptual Model for Visualising Concurrent Java Programs Using UML

Author

Leroux, H, Mingins, C, and Requile-Romanczuk, A

Subjects
Other information and computing sciences not elsewhere classified
Abstract

Understanding concurrent object-oriented software execution is not a trivial task. This is mainly due to the interleaving of threads, and multiple flows of control that result in different outputs being produced at successive executions of the program. We believe that visualisation can be of assistance to developers in expediting the comprehension of concurrent object-oriented software. In this paper, we discuss the issues associated with concurrency and the challenges faced when attempting to display these issues visually. We present Jacot, an environment to exemplify the intricacies of concurrency in Java at run-time. This environment is based on the Unified Modeling Language (UML) paradigm and uses the Java Debug Interface (JDI) for event gathering. The visualisation model also defines extensions to be made to the UML to incorporate concurrency constructs. The originality of this research is its aim at completeness of representation of concurrency issues.

Published
2022
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35. Sample return of primitive matter from the outer Solar System

Author

Vernazza, P., primary, Beck, P., additional, Ruesch, O., additional, Bischoff, A., additional, Bonal, L., additional, Brennecka, G., additional, Brunetto, R., additional, Busemann, H., additional, Carter, J., additional, Carli, C., additional, Cartier, C., additional, Ciarniello, M., additional, Debaille, V., additional, Delsanti, A., additional, D’Hendecourt, L., additional, Füri, E., additional, Groussin, O., additional, Guilbert-Lepoutre, A., additional, Helbert, J., additional, Hoppe, P., additional, Jehin, E., additional, Jorda, L., additional, King, A., additional, Kleine, T., additional, Lamy, P., additional, Lasue, J., additional, Le Guillou, C., additional, Leroux, H., additional, Leya, I., additional, Magna, T., additional, Marrocchi, Y., additional, Morlok, A., additional, Mousis, O., additional, Palomba, E., additional, Piani, L., additional, Quirico, E., additional, Remusat, L., additional, Roskosz, M., additional, Rubin, M., additional, Russell, S., additional, Schönbächler, M., additional, Thomas, N., additional, Villeneuve, J., additional, Vinogradoff, V., additional, Wurz, P., additional, and Zanda, B., additional

Published
2021
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36. Investigation of current models of care for genetic heart disease in Australia: A national clinical audit

Author

Austin, R, Quinn, MCJ, Afoakwah, C, Metke-Jimenez, A, Leroux, H, Atherton, J, Brown, JS, Wornham, LJ, Macciocca, I, de Silva, MG, Thompson, T, Martin, EM, Hilton, D, Devery, S, Wu, KHC, Jackson, MR, Correnti, G, Overkov, A, Elbracht-Leong, S, Ingles, J, Scuffham, P, Semsarian, C, McGaughran, J, Austin, R, Quinn, MCJ, Afoakwah, C, Metke-Jimenez, A, Leroux, H, Atherton, J, Brown, JS, Wornham, LJ, Macciocca, I, de Silva, MG, Thompson, T, Martin, EM, Hilton, D, Devery, S, Wu, KHC, Jackson, MR, Correnti, G, Overkov, A, Elbracht-Leong, S, Ingles, J, Scuffham, P, Semsarian, C, and McGaughran, J

Abstract

BACKGROUND: This sub-study of the Australian Genomics Cardiovascular Genetic Disorders Flagship sought to conduct the first nation-wide audit in Australia to establish the current practices across cardiac genetics clinics. METHOD: An audit of records of patients with a suspected genetic heart disease (cardiomyopathy, primary arrhythmia, autosomal dominant congenital heart disease) who had a cardiac genetics consultation between 1st January 2016 and 31 July 2018 and were offered a diagnostic genetic test. RESULTS: This audit included 536 records at multidisciplinary cardiac genetics clinics from 11 public tertiary hospitals across five Australian states. Most genetic consultations occurred in a clinic setting (90%), followed by inpatient (6%) and Telehealth (4%). Queensland had the highest proportion of Telehealth consultations (9% of state total). Sixty-six percent of patients had a clinical diagnosis of a cardiomyopathy, 28% a primary arrhythmia, and 0.7% congenital heart disease. The reason for diagnosis was most commonly as a result of investigations of symptoms (73%). Most patients were referred by a cardiologist (85%), followed by a general practitioner (9%) and most genetic tests were funded by the state Genetic Health Service (73%). Nationally, 29% of genetic tests identified a pathogenic or likely pathogenic gene variant; 32% of cardiomyopathies, 26% of primary arrhythmia syndromes, and 25% of congenital heart disease. CONCLUSION: We provide important information describing the current models of care for genetic heart diseases throughout Australia. These baseline data will inform the implementation and impact of whole genome sequencing in the Australian healthcare landscape.

Published
2021

37. Mechanical twinning of monazite expels radiogenic lead

Author

Fougerouse, Denis, Reddy, Steven, Seydoux-Guiiiaume, A.M., Kirkland, Chris, Erickson, Timmons, Saxey, David, Rickard, William, Jacob, D., Leroux, H., Clark, Chris, Fougerouse, Denis, Reddy, Steven, Seydoux-Guiiiaume, A.M., Kirkland, Chris, Erickson, Timmons, Saxey, David, Rickard, William, Jacob, D., Leroux, H., and Clark, Chris

Abstract

Mechanical twins form by the simple shear of the crystal lattice during deformation. In order to test the potential of narrow twins in monazite to record the timing of their formation, we investigated a ca. 1700 Ma monazite grain (from the Sandmata Complex, Rajasthan, India) deformed at ca. 980 Ma, by electron backscattered diffraction (EBSD), transmission electron microscopy (TEM), and atom probe tomography (APT). APT 208Pb/232Th ages indicate that the twin was entirely reset by radiogenic Pb loss during its formation at conditions far below the monazite closure temperature. The results are consistent with a model where Pb is liberated during rupture of rare earth element-oxygen (REE-O) bonds in the large [REE]O9 polyhedra during twinning. Liberated Pb likely migrated along fast diffusion pathways such as crystal defects. The combination of a quantitative microstructural investigation and nano-geochronology provides a new approach for understanding the history of accessory phases.

Published
2021

39. STEM and STXM-XANES analysis of FIB sections of Ultracarbonaceous Antarctic Micrometeorites (UCAMMs)

Author

Guérin, B, Engrand, C, Le Guillou, C, Leroux, H, Duprat, J, Dartois, E, Bernard, S, Ben- Zerara, K, Rojas, J, Godard, M, Delauche, L, Troadec, David, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Centrale de Micro Nano Fabrication - IEMN (CMNF-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Renatech Network, and Centrale de Micro Nano Fabrication - IEMN (CMNF - IEMN)

Subjects
[SDU]Sciences of the Universe [physics], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract

International audience; Introduction: Ultracarbonaceous Antarctic Micrometeorites (UCAMMS) are extraterrestrial dust particles containing large amount of carbonaceous material with elevated D/H ratios [1] and high N/C atomic ratio (up to 0.2)[2]. UCAMMS are rare (~ 1% of the particles in the Concordia meteorite collection) but they have been identified in several collection of interplanetary dust [3, 4]. They are most probably of cometary origin. Here, we studied the association of organic matter and minerals by scanning transmission X-ray microscopy (STXM-XANES) coupled with scanning transmission electronic microscopy (TEM/STEM). Samples and Methods: The UCAMMs studied here were collected in the Antarctic snow, close to the Concordia station at Dome C [3]. FIB sections of 8 UCAMMs (DC06-18, DC06-41, DC06-43, DC06-65, DC06-308, DC06-139, DC16-30, DC16-309) were analyzed using synchrotron based STXM-XANES at the carbon, nitrogen and oxygen K-edges. The FIB sections were subsequently analyzed with transmission electron microscopy (TEM/STEM) using a FEI Tecnai G2 20 and a FEI TITAN Themis 300 [5, 6]. Peak identification of STXM-XANES spectra are based on [7]. XANES spectra are processed and quantified using Quantorxs method [8] and quantification of STEM EDS spectra has been realized using Hyperspy software [9]. Here, we mainly present results obtained on two recently identified UCAMMs (DC06-308 and DC16-309) and compare them with previous observations [1, 5, 6]. Results: The STXM-XANES analysis reveals 3 types of organic matter (OM) characterized by different carbon speciation. Figure 1 shows type I OM in blue and type II OM in green, both having spectra close to that of chondritic insoluble organic matter (IOM). The main peaks of type I and II OMs are found around 284.8 eV (aromatic and olefinic groups (C=C)), 286.4 eV (ketone and phenol C=O) and 288.4 eV (carboxyl O=C-O). Type II OM exhibits similar functional groups as type I OM but the first peak position is shifted to 285 eV, indicating a stronger contribution of the aromatic groups. The atomic N/C ratio of types I/II OMs range between 0.01 and 0.05 (1σ=0.02) similar to those of chondritic IOM. The type III, in red on Figure 1 exhibits larger differences. The main peak is at 286.4 eV (C≡N nitrile), a small peak at 284.8 eV (alkene

Published
2020

40. Risk prediction of late-onset Alzheimer’s disease implies an oligogenic architecture

Author

Zhang, Q, Sidorenko, J, Couvy-Duchesne, B, Marioni, RE, Wright, MJ, Goate, AM, Marcora, E, Huang, KL, Porter, T, Laws, SM, Masters, CL, Bush, AI, Fowler, C, Darby, D, Pertile, K, Restrepo, C, Roberts, B, Robertson, J, Rumble, R, Ryan, T, Collins, S, Thai, C, Trounson, B, Lennon, K, Li, QX, Ugarte, FY, Volitakis, I, Vovos, M, Williams, R, Baker, J, Russell, A, Peretti, M, Milicic, L, Lim, L, Rodrigues, M, Taddei, K, Taddei, T, Hone, E, Lim, F, Fernandez, S, Rainey-Smith, S, Pedrini, S, Martins, R, Doecke, J, Bourgeat, P, Fripp, J, Gibson, S, Leroux, H, Hanson, D, Dore, V, Zhang, P, Burnham, S, Rowe, CC, Villemagne, VL, Yates, P, Pejoska, SB, Jones, G, Ames, D, Cyarto, E, Lautenschlager, N, Barnham, K, Cheng, L, Hill, A, Killeen, N, Maruff, P, Silbert, B, Brown, B, Sohrabi, H, Savage, G, Vacher, M, Sachdev, PS, Mather, KA, Armstrong, NJ, Thalamuthu, A, Brodaty, H, Yengo, L, Yang, J, Wray, NR, McRae, AF, Visscher, PM, Zhang, Q, Sidorenko, J, Couvy-Duchesne, B, Marioni, RE, Wright, MJ, Goate, AM, Marcora, E, Huang, KL, Porter, T, Laws, SM, Masters, CL, Bush, AI, Fowler, C, Darby, D, Pertile, K, Restrepo, C, Roberts, B, Robertson, J, Rumble, R, Ryan, T, Collins, S, Thai, C, Trounson, B, Lennon, K, Li, QX, Ugarte, FY, Volitakis, I, Vovos, M, Williams, R, Baker, J, Russell, A, Peretti, M, Milicic, L, Lim, L, Rodrigues, M, Taddei, K, Taddei, T, Hone, E, Lim, F, Fernandez, S, Rainey-Smith, S, Pedrini, S, Martins, R, Doecke, J, Bourgeat, P, Fripp, J, Gibson, S, Leroux, H, Hanson, D, Dore, V, Zhang, P, Burnham, S, Rowe, CC, Villemagne, VL, Yates, P, Pejoska, SB, Jones, G, Ames, D, Cyarto, E, Lautenschlager, N, Barnham, K, Cheng, L, Hill, A, Killeen, N, Maruff, P, Silbert, B, Brown, B, Sohrabi, H, Savage, G, Vacher, M, Sachdev, PS, Mather, KA, Armstrong, NJ, Thalamuthu, A, Brodaty, H, Yengo, L, Yang, J, Wray, NR, McRae, AF, and Visscher, PM

Abstract

Genetic association studies have identified 44 common genome-wide significant risk loci for late-onset Alzheimer’s disease (LOAD). However, LOAD genetic architecture and prediction are unclear. Here we estimate the optimal P-threshold (Poptimal) of a genetic risk score (GRS) for prediction of LOAD in three independent datasets comprising 676 cases and 35,675 family history proxy cases. We show that the discriminative ability of GRS in LOAD prediction is maximised when selecting a small number of SNPs. Both simulation results and direct estimation indicate that the number of causal common SNPs for LOAD may be less than 100, suggesting LOAD is more oligogenic than polygenic. The best GRS explains approximately 75% of SNP-heritability, and individuals in the top decile of GRS have ten-fold increased odds when compared to those in the bottom decile. In addition, 14 variants are identified that contribute to both LOAD risk and age at onset of LOAD.

Published
2020

42. Mechanical twinning of monazite expels radiogenic lead

Author

Fougerouse, D., primary, Reddy, S.M., additional, Seydoux-Guillaume, A.-M., additional, Kirkland, C.L., additional, Erickson, T.M., additional, Saxey, D.W., additional, Rickard, W.D.A., additional, Jacob, D., additional, Leroux, H., additional, and Clark, C., additional

Published
2020
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43. Finding Interstellar Particle Impacts on Stardust Aluminium Foils: The Safe Handling, Imaging, and Analysis of Samples Containing Femtogram Residues

Author

Kearsley, A. T, Westphal, A. J, Stadermann, F. J, Armes, S. P, Ball, A. D, Borg, J, Bridges, J. C, Brownlee, D. E, Burchell, M. J, Chater, R. J, Davis, A. M, Floss, C, Flynn, G, Gainsforth, Z, Gruen, E, Heck, P, Hoppe, P, Hoerz, F, Howard, L. E, Howe, G, Huss, G. R, Huth, J, Landgraf, M, Leitner, J, and Leroux, H

Subjects
Space Sciences (General)
Abstract

Impact ionisation detectors on a suite of spacecraft have shown the direction, velocity, flux and mass distribution of smaller ISP entering the Solar System. During the aphelion segments of the Stardust flight, a dedicated collector surface was oriented to intercept ISP of beta = 1, and returned to Earth in January 2006. In this paper we describe the probable appeareance and size of IS particle craters from initial results of experimental impacts and numerical simulation, explain how foils are being prepared and mounted for crater searching by automated acquisition of high magnification electron images (whilst avoiding contamination of the foils) and comment on appropriate analytical techniques for Preliminary Examination (PE).

Published
2010

44. Spectral and Microstructural Modifications of Olivine Under Ion Irradiation

Author

Leroux, H., de la Peña, F., Le Guillou, C., Lantz, C., Brunetto, R., Unité Matériaux et Transformations - UMR 8207 (UMET), Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL), Department of Materials Science and Metallurgy [Cambridge University] (DMSM), University of Cambridge [UK] (CAM), GMG Institute, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract

International audience; We present new results of ion irradiation experiments on Fe-rich olivine. We focus on the relationships between the spectral properties in the VIS-NIR and in the MIR and nanostructures studied by TEM and associated spectroscopies EELS and EDX.

Published
2019

45. Northwest africa 12563 cm2-an, and the different alteration styles in c2 chondrites

Author

Hewins, K. H., Zanetta, P. -M, Zanda, B., Le Guillou, C., Jerome Gattacceca, Sognzoni, C., Pont, S., Piani, L., Rigaudier, T., Leroux, H., Bernard, S., Deldicque, D., Marrocchi, Y., Rutgers University [Camden], Rutgers University System (Rutgers), Université Pierre et Marie Curie - Paris 6 (UPMC), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Cachan (ENS Cachan), Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), and ProdInra, Migration

Subjects
[SDV] Life Sciences [q-bio], [SDV]Life Sciences [q-bio], cm, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

46. Preparing sample return from Ryugu and Bennu asteroids with micrometeorites from the Concordia collection

Author

Duprat, J, Engrand, C, Dartois, E, Mathurin, J, Bernard, S, Le Guillou, C, Leroux, H, Vuitton, V, Orthous-Daunay, F.-R, Auge, B, Guerin, B, Rojas, J, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique D'Orsay (LCPO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)

Subjects
asteroid, interplanetary organic matter, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], micrometeorites, Solar System, space sample return mission
Abstract

International audience; Hayabusa 2 and OSIRIS-REx space missions will give a unique access to study the composition of carbonaceous asteroids. A key issue will be the comparison of the organic and mineral compounds from these near-Earth active carbonaceous asteroids with that of carbonaceous chondrites, carbon-rich interplanetary dust particles and cometary samples (81P/Wild2 or in-situ analyses from 67P/CG). The comparison of Ryugu and Bennu samples with chondritic micrometeorites and with extremely carbon-rich interplanetary dust particles such as the Ultra-Carbonaceous MicroMeteorites (UCAMMs) will provide a unique tool to assess their possible links with cometary organics. Analytical methods applied to study micrometeorites from Concordia collection (Antarctica) and the most recent results obtained will be summarised. A particular emphasis will be put on the dedicated experimental protocols that we developed to analyse such micrometeorite fragments and study their mineral-organic association at scales relevant to their intimate association, ranging from tens of nanometers to a few microns.

Published
2019

47. Inner Solar System Irradiation History of Minerals in an Ultracarbonaceous Antarctic Micrometeorite (UCAMM)

Author

Engrand, Cecile, Charon, E., Leroux, H., Le Guillou, C., Duprat, J., Dartois, E., Bernard, S, Guérin, Baptiste, Delauche, L., Godard, M., Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Edifices Nanométriques (LEDNA), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL), Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM AS), Université Paris-Saclay-Univ. Paris-Sud-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Univ. Paris-Sud, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA), Laboratoire de géologie de l'ENS (LGE), and École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)

Subjects
[SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

48. Preliminary Examination of the Interstellar Collector of Stardust

Author

Westphal, A. J, Allen, C, Bastien, R, Borg, J, Brenker, F, Bridges, J, Brownlee, D. E, Butterworth, A. L, Floss, C, Flynn, G, Frank, D, Gainsforth, Z, Gruen, E, Hoppe, P, Kearsley, A, Leroux, H, Nittler, L. R, Sandford, S. A, Simionovici, A, Stadermann, F, Stroud, M, Tsou, P, Tyliczszak, T, Warren, J, and Zolensky, M. E

Subjects
Lunar And Planetary Science And Exploration
Abstract

The findings of the Stardust spacecraft mission returned to earth in January 2006 are discussed. The spacecraft returned two unprecedented and independent extraterrestrial samples: the first sample of a comet and the first samples of contemporary interstellar dust. An important lesson from the cometary Preliminary Examination (PE) was that the Stardust cometary samples in aerogel presented a technical challenge. Captured particles often separate into multiple fragments, intimately mix with aerogel and are typically buried hundreds of microns to millimeters deep in the aerogel collectors. The interstellar dust samples are likely much more challenging since they are expected to be orders of magnitudes smaller in mass, and their fluence is two orders of magnitude smaller than that of the cometary particles. The goal of the Stardust Interstellar Preliminary Examination (ISPE) is to answer several broad questions, including: which features in the interstellar collector aerogel were generated by hypervelocity impact and how much morphological and trajectory information may be gained?; how well resolved are the trajectories of probable interstellar particles from those of interplanetary origin?; and, by comparison to impacts by known particle dimensions in laboratory experiments, what was the mass distribution of the impacting particles? To answer these questions, and others, non-destructive, sequential, non-invasive analyses of interstellar dust candidates extracted from the Stardust interstellar tray will be performed. The total duration of the ISPE will be three years and will differ from the Stardust cometary PE in that data acquisition for the initial characterization stage will be prolonged and will continue simultaneously and parallel with data publications and release of the first samples for further investigation.

Published
2008

49. Carbonate in Comets: A Comparison of Comets 1P/Halley, 9P/Temple 1, and 81P/Wild 2

Author

Flynn, G. J, Leroux, H, Tomeoka, K, Tomioka, N, Ohnishi, I, Mikouchi, T, Wirick, S, Keller, L. P, Jacobsen, C, and Sanford, S. A

Subjects
Astrophysics
Abstract

Comets are generally believed to have formed in a cold region, trapping in the cometary ices the original low-temperature condensate grains of our Solar System. These grains would have been preserved in cold-storage, at a temperature below the freezing point of CO2, for the last 4.5+ billion years. Carbonates are common in hydrous meteorites and hydrous interplanetary dust particles (IDPs), where they are believed to have formed by parent-body aqueous processing. Since simple models of cometary evolution involve no aqueous processing, carbonates were generally presumed not to occur in comets. However, Toppani et al. [1] have performed experiments that indicate carbonate can be formed by non-equilibrium condensation in circumstellar environments where water is present as a vapor, not as a liquid. This suggests carbonate might have condensed in cold regions of the Solar Nebula, and might be present in comets.

Published
2008

50. SEM-EDS Analyses of Small Craters in Stardust Aluminum Foils: Implications for the Wild-2 Dust Distribution

Author

Borg, J, Horz, F, Bridges, J. C, Burchell, M. J, Djouadi, Z, Floss, C, Graham, G. A, Green, S. F, Heck, P. R, Hoppe, P, Huth, J, Kearsley, A, Leroux, H, Marhas, K, Stadermann, F. J, and Teslich, N

Subjects
Lunar And Planetary Science And Exploration
Abstract

Aluminium foils were used on Stardust to stabilize the aerogel specimens in the modular collector tray. Part of these foils were fully exposed to the flux of cometary grains emanating from Wild 2. Because the exposed part of these foils had to be harvested before extraction of the aerogel, numerous foil strips some 1.7 mm wide and 13 or 33 mm long were generated during Stardusts's Preliminary Examination (PE). These strips are readily accommodated in their entirety in the sample chambers of modern SEMs, thus providing the opportunity to characterize in situ the size distribution and residue composition - employing EDS methods - of statistically more significant numbers of cometary dust particles compared to aerogel, the latter mandating extensive sample preparation. We describe here the analysis of nearly 300 impact craters and their implications for Wild 2 dust.

Published
2007

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