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123 results on '"Accolla, M."'

2. Quantum tunneling of oxygen atoms on very cold surfaces

Author

Minissale, M., Congiu, E., Baouche, S., Chaabouni, H., Moudens, A., Dulieu, F., Accolla, M., Cazaux, S., Manico, G., and Pirronello, V.

Subjects
Condensed Matter - Materials Science, Astrophysics - Cosmology and Extragalactic Astrophysics, Physics - Chemical Physics, 85
Abstract

Any evolving system can change of state via thermal mechanisms (hopping a barrier) or via quantum tunneling. Most of the time, efficient classical mechanisms dominate at high temperatures. This is why an increase of the temperature can initiate the chemistry. We present here an experimental investigation of O-atom diffusion and reactivity on water ice. We explore the 6-25 K temperature range at sub-monolayer surface coverages. We derive the diffusion temperature law and observe the transition from quantum to classical diffusion. Despite of the high mass of O, quantum tunneling is efficient even at 6 K. As a consequence, the solid-state astrochemistry of cold regions should be reconsidered and should include the possibility of forming larger organic molecules than previously expected., Comment: 13 pages, 4 figures

Published
2014
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3. Gas temperature dependent sticking of hydrogen on cold amorphous water ice surfaces of interstellar interest

Author

Matar, E., Bergeron, H., Dulieu, F., Chaabouni, H., Accolla, M., and Lemaire, J. L.

Subjects
Physics - Chemical Physics
Abstract

Using the King & Wells method, we present experimental data on the dependence of the sticking of molecular hydrogen and deuterium on the beam temperature onto non- porous amorphous solid water (ASW) ice surfaces of interstellar interest. A statistical model that explains the isotopic effect and the beam temperature behavior of our data is proposed. This model gives an understanding of the discrepancy between all known experimental results on the sticking of molecular hydrogen. Moreover it is able to fit the theoretical results of V. Buch et al. [Astrophys. J. (1991), 379, 647] on atomic hydrogen and deuterium. For astrophysical applications, an analytical formula for the sticking coefficients of H, D, H2, D2 and HD in the case of a gas phase at thermal equilibrium is also provided at the end of the article.

Published
2010
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4. Experimental evidence for water formation via ozone hydrogenation on dust grains at 10 K

Author

Mokrane, H., Chaabouni, H., Accolla, M., Congiu, E., Dulieu, F., Chehrouri, M., and Lemaire, J. L.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

The formation of water molecules from the reaction between ozone (O3) and D-atoms is studied experimentally for the first time. Ozone is deposited on non-porous amorphous solid water ice (H2O), and D-atoms are then sent onto the sample held at 10 K. HDO molecules are detected during the desorption of the whole substrate where isotope mixing takes place, indicating that water synthesis has occurred. The efficiency of water formation via hydrogenation of ozone is of the same order of magnitude of that found for reactions involving O atoms or O2 molecules and exhibits no apparent activation barrier. These experiments validate the assumption made by models using ozone as one of the precursors of water formation via solid-state chemistry on interstellar dust grains., Comment: 16 pages, 2 figures, to be published on ApJL

Published
2009
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7. Dust measurements in the coma of comet 67P/Churyumov-Gerasimenko inbound to the Sun

Author

Rotundi, A., Sierks, H., Corte, V. Della, Fulle, M., Gutierrez, P. J., Lara, L., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Rickman, H., Keller, H. U., López-Moreno, J. J., Accolla, M., Agarwal, J., A'Hearn, M. F., Altobelli, N., Angrilli, F., Barucci, M. A., Bertaux, J.-L., Bertini, I., Bodewits, D., Bussoletti, E., Colangeli, L., Cosi, M., Cremonese, G., Crifo, J.-F., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., Esposito, F., Ferrari, M., Fornasier, S., Giovane, F., Gustafson, B., Green, S. F., Groussin, O., Grün, E., Güttler, C., Herranz, M. L., Hviid, S. F., Ip, W., Ivanovski, S., Jerónimo, J. M., Jorda, L., Knollenberg, J., Kramm, R., Kührt, E., Küppers, M., Lazzarin, M., Leese, M. R., López-Jiménez, A. C., Lucarelli, F., Lowry, S. C., Marzari, F., Epifani, E. Mazzotta, McDonnell, J. A. M., Mennella, V., Michalik, H., Molina, A., Morales, R., Moreno, F., Mottola, S., Naletto, G., Oklay, N., Ortiz, J. L., Palomba, E., Palumbo, P., Perrin, J.-M., Rodríguez, J., Sabau, L., Snodgrass, C., Sordini, R., Thomas, N., Tubiana, C., Vincent, J.-B., Weissman, P., Wenzel, K.-P., Zakharov, V., and Zarnecki, J. C.

Published
2015

10. Prevalence of non-aromatic carbonaceous molecules in the inner regions of circumstellar envelopes

Author

Martínez L., Santoro G., Merino P., Accolla M., Lauwaet K., Sobrado J., Sabbah H., Pelaez R.J., Herrero V.J., Tanarro I., Agúndez M., Martín-Jimenez A., Otero R., Ellis G.J., Joblin C., Cernicharo J., Martín-Gago J.A. and We thank the European Research Council for funding support under Synergy Grant ERC-2013-SyG, G.A. 610256 (NANOCOSMOS). We also acknowledge partial support from the Spanish Research Agency (AEI) through grants MAT2017-85089-c2-1R, FIS2016-77578-R and FIS2016-77726-C3-1-P. Support from the FotoArt-CM Project (P2018/NMT-4367) through the Program of R&D activities between research groups in Technologies 2013, cofinanced by European Structural Funds, is also recognized.

Published
2020

11. INFRA-ICE: An ultra-high vacuum experimental station for laboratory astrochemistry

Author

Santoro G., Sobrado J.M., Tajuelo-Castilla G., Accolla M., Martínez L., Azpeitia J., Lauwaet K., Cernicharo J., Ellis G.J., Martín-Gago J.Á. and We thank the European Research Council for funding support under Synergy Grant No. ERC-2013-SyG, G.A. 610256 (NANOCOSMOS). In addition, partial support from the Spanish Research Agency (AEI) through Grant Nos. MAT2017-85089-c2-1R and FIS2016-77578-R is acknowledged. Support from the FotoArt-CM Project (No. P2018/NMT 4367) through the Program of R&D activities between research groups in Technologies 2013, co-financed by European Structural Funds, is also acknowledged. G.T.-C. acknowledges funding from the Comunidad Autónoma de Madrid (Grant No. PEJD-2018-PRE/IND-9029). G.S. and G.J.E. would like to thank Stephane Lefrançois for valuable discussions on the mechanical details of the optical coupling.

Published
2020

13. The Chemistry of Cosmic Dust Analogs from C, C2, and C2H2 in C-rich Circumstellar Envelopes

Author

Santoro G., Martínez L., Lauwaet K., Accolla M., Tajuelo-Castilla G., Merino P., Sobrado J.M., Peláez R.J., Herrero V.J., Tanarro I., Mayoral A., Agúndez M., Sabbah H., Joblin C., Cernicharo J., Martín-Gago J.A., Santoro G., Martínez L., Lauwaet K., Accolla M., Tajuelo-Castilla G., Merino P., Sobrado J.M., Peláez R.J., Herrero V.J., Tanarro I., Mayoral A., Agúndez M., Sabbah H., Joblin C., Cernicharo J., and Martín-Gago J.A.

Published
2020

14. Prevalence of non-aromatic carbonaceous molecules in the inner regions of circumstellar envelopes

Author

Martínez L., Santoro G., Merino P., Accolla M., Lauwaet K., Sobrado J., Sabbah H., Pelaez R.J., Herrero V.J., Tanarro I., Agúndez M., Martín-Jimenez A., Otero, Roberto, Ellis G.J., Joblin C., Cernicharo J., Martín-Gago J.A., Martínez L., Santoro G., Merino P., Accolla M., Lauwaet K., Sobrado J., Sabbah H., Pelaez R.J., Herrero V.J., Tanarro I., Agúndez M., Martín-Jimenez A., Otero, Roberto, Ellis G.J., Joblin C., Cernicharo J., and Martín-Gago J.A.

Published
2020

16. Electrical properties of Itokawa grains returned by Hayabusa

Author

Cipriani, F., Drozdovski, N., Koschny, D., Colangeli, L., Ferrari, M., Della Corte, V., Accolla, M., Butler, B., Rotundi, A., Shortt, B., Sanders, S., C.v.d. Luijt, D., and Breeveld, D.

Abstract

第8回極域科学シンポジウム/個別セッション：[OA] 南極隕石 / はやぶさ12月5日（火）国語研究所 2階講堂The Eighth Symposium on Polar Science/Ordinary sessions: [OA] Antarctic meteorites / HayabusaTue. 5 Dec./2F Auditorium, National Institute for Japanese Language and Linguistics

Published
2017

18. Water formation through O2 + D pathway on cold silicate and amorphous water ice surfaces of interstellar interest.

Author

Chaabouni, H., Minissale, M., Manicò, G., Congiu, E., Noble, J. A., Baouche, S., Accolla, M., Lemaire, J. L., Pirronello, V., and Dulieu, F.

Subjects
WATER, SILICATES, MONOMOLECULAR films, SURFACES (Physics), POROUS materials, CHEMICAL reactions
Abstract

The formation of the first monolayer of water molecules on bare dust grains is of primary importance to understand the growth of the icy mantles that cover dust in the interstellar medium. In this work, we explore experimentally the formation of water molecules from O2 + D reaction on bare silicate surfaces that simulates the grains present in the diffuse interstellar clouds at visual extinctions (AV < 3 mag). For comparison, we also study the formation of water molecules on surfaces covered with amorphous water ice representing the dense clouds (AV >= 3 mag). Our studies focus on the formation of water molecules in the sub-monolayer and monolayer regimes using reflection absorption infrared spectroscopy and temperature-programmed desorption techniques. We provide the fractions of the products, such as D2O and D2O2 molecules formed on three astrophysically relevant surfaces held at 10 K (amorphous olivine-type silicate, porous amorphous water ice, and nonporous amorphous water ice). Our results showed that the formation of D2O molecules occurs with an efficiency of about 55%-60% on nonporous amorphous water ice and about 18% on bare silicate grains surfaces. We explain the low efficiency of D2O water formation on the silicate surfaces by the desorption upon formation of certain products once the reaction occurs between O2 and D atoms on the surface. A kinetic model taking into account the chemical desorption of newly formed water supports our conclusions. [ABSTRACT FROM AUTHOR]

Published
2012
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19. GIADA performance during Rosetta mission scientific operations at comet 67P

Author

Agenzia Spaziale Italiana, Sordini, R., Della Corte, V., Rotundi, A., Rotunno, S., Ferrari, M., Ivanovski, S.L., Colangeli, L., Palumbo, P., López-Moreno, José Juan, Rodríguez Gómez, Julio, Fulle, M., Green, S. F., Mazzotta-Epifani, E., Morales, Rafael, Accolla, M., Palomba, E., Cosi, M., Herranz, Miguel, Liuzzi, V., Agenzia Spaziale Italiana, Sordini, R., Della Corte, V., Rotundi, A., Rotunno, S., Ferrari, M., Ivanovski, S.L., Colangeli, L., Palumbo, P., López-Moreno, José Juan, Rodríguez Gómez, Julio, Fulle, M., Green, S. F., Mazzotta-Epifani, E., Morales, Rafael, Accolla, M., Palomba, E., Cosi, M., Herranz, Miguel, and Liuzzi, V.

Abstract

The Grain Impact Analyser and Dust Accumulator (GIADA) instrument onboard Rosetta studied the dust environment of comet 67P/Churyumov–Gerasimenko from 3.7 au inbound, through perihelion, to 3.8 au outbound, measuring the dust flow and the dynamic properties of individual particles. GIADA is composed of three subsystems: (1) Grain Detection System (GDS); (2) Impact Sensor (IS); and (3) Micro-Balances System (MBS). Monitoring the subsystems’ performance during operations is an important element for the correct calibration of scientific measurements. In this paper, we analyse the GIADA inflight calibration data obtained by internal calibration devices for the three subsystems during the period from 1 August 2014 to 31 October 2015. The calibration data testify a nominal behaviour of the instrument during these fifteen months of mission; the only exception is a minor loss of sensitivity for one of the two GDS receivers, attributed to dust contamination.© 2017 COSPAR

Published
2018

20. Electrical properties of Itokawa grains returned by the Hayabusa mission

Author

Cipriani, F., Drozdovski, N., Koschny, D., Ferrari, M., Della Corte, V., Accolla, M., Butler, B., Rotundi, A., Sanders, S., Luijt, C.v.d., and Duvet, L.

Abstract

第7回極域科学シンポジウム:[OA] 南極隕石/はやぶさ11月29日（火）国立極地研究所 1階交流アトリウム

Published
2016

21. Improvements in the calibration of GIADA's measurement subsystems

Author

Sordini, R., Della Corte, V., Rotundi, A., Accolla, M., Marco Ferrari, Ivanovski, S., Lucarelli, F., Mazzotta Epifani, E., Palumbo, P., and ITA

Abstract

The Grain Impact Analyzer and Dust Accumulator (GIADA) is an in-situ instrument devoted to measure the dynamical properties of the dust grains emitted by the comet. Using the GIADA Proto Flight Model (PFM), installed in a clean room in our laboratory, an extended calibration activity \citep{Sordini14} has been carried out taking into account the knowledge gained through the analyses of IDPs and cometary samples returned from comet 81P/Wild 2 \citep{Brownlee et al. 2006, Rotundi et al. 2014}. GIADA consists of three measurement subsystems: the Grain Detection System, an optical device measuring the optical cross-section of single grain without affecting its dynamical properties; the Impact Sensor that measures the momentum released from each grain that impacts its sensitive surface, and the Micro Balance System, a network of five Quartz Micro Balances measuring the cumulative dust deposition from different space directions \citep{DellaCorte14}. The results of the analyses on data acquired with the GIADA PFM and the comparison with calibration data acquired during the pre-launch campaign allowed us to improve GIADA performances and capabilities. We report the results of the following main activities: - definition of a correlation between the two GIADA Models, i.e. PFM and In-Flight Model on-board Rosetta; - characterization of the sub-systems performances (signal elaboration, sensitivities, space environment effects); - new calibration measurements and related curves by means of the GIADA PFM using realistic cometary dust analogues \citep{Ferrari14}. All the analyses performed during this extended calibration activity are allowing to fully characterize the dynamic parameters of the dust particles ejected by the comet 67P/Churyumov-Gerasimenko \citep{Rotundi et al. 2015, Fulle et al. 2015, Della Corte et al. 2015}.

Published
2016

22. The dust-to-ices ratio in comets and Kuiper belt objects

Author

Fulle, M., primary, Della Corte, V., additional, Rotundi, A., additional, Green, S. F., additional, Accolla, M., additional, Colangeli, L., additional, Ferrari, M., additional, Ivanovski, S., additional, Sordini, R., additional, and Zakharov, V., additional

Published
2017
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24. Evolution Of The Dust Size Distribution Of Comet 67P/Churyumov-Gerasimenko From 2.2 Au To Perihelion

Author

Fulle, M., Marzari, F., Della Corte, V., Fornasier, S., Sierks, H., Rotundi, A., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Rickman, Hans, Keller, H. U., Lopez-Moreno, J. J., Accolla, M., Agarwal, J., A'Hearn, M. F., Altobelli, N., Barucci, M. A., Bertaux, J. -L, Bertini, I., Bodewits, D., Bussoletti, E., Colangeli, L., Cosi, M., Cremonese, G., Crifo, J. -F, Da Deppo, V., Davidsson, Björn, Debei, S., De Cecco, M., Esposito, F., Ferrari, M., Giovane, F., Gustafson, B., Green, S. F., Groussin, O., Gruen, E., Gutierrez, P., Guettler, C., Herranz, M. L., Hviid, S. F., Ip, W., Ivanovski, S. L., Jeronimo, J. M., Jorda, L., Knollenberg, J., Kramm, R., Kuehrt, E., Kueppers, M., Lara, L., Lazzarin, M., Leese, M. R., Lopez-Jimenez, A. C., Lucarelli, F., Epifani, E. Mazzotta, McDonnell, J. A. M., Mennella, V., Molina, A., Morales, R., Moreno, F., Mottola, S., Naletto, G., Oklay, N., Ortiz, J. L., Palomba, E., Palumbo, P., Perrin, J. -M, Rietmeijer, F. J. M., Rodriguez, J., Sordini, R., Thomas, N., Tubiana, C., Vincent, J. -B, Weissman, P., Wenzel, K. -P, Zakharov, V., Zarnecki, J. C., Fulle, M., Marzari, F., Della Corte, V., Fornasier, S., Sierks, H., Rotundi, A., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Rickman, Hans, Keller, H. U., Lopez-Moreno, J. J., Accolla, M., Agarwal, J., A'Hearn, M. F., Altobelli, N., Barucci, M. A., Bertaux, J. -L, Bertini, I., Bodewits, D., Bussoletti, E., Colangeli, L., Cosi, M., Cremonese, G., Crifo, J. -F, Da Deppo, V., Davidsson, Björn, Debei, S., De Cecco, M., Esposito, F., Ferrari, M., Giovane, F., Gustafson, B., Green, S. F., Groussin, O., Gruen, E., Gutierrez, P., Guettler, C., Herranz, M. L., Hviid, S. F., Ip, W., Ivanovski, S. L., Jeronimo, J. M., Jorda, L., Knollenberg, J., Kramm, R., Kuehrt, E., Kueppers, M., Lara, L., Lazzarin, M., Leese, M. R., Lopez-Jimenez, A. C., Lucarelli, F., Epifani, E. Mazzotta, McDonnell, J. A. M., Mennella, V., Molina, A., Morales, R., Moreno, F., Mottola, S., Naletto, G., Oklay, N., Ortiz, J. L., Palomba, E., Palumbo, P., Perrin, J. -M, Rietmeijer, F. J. M., Rodriguez, J., Sordini, R., Thomas, N., Tubiana, C., Vincent, J. -B, Weissman, P., Wenzel, K. -P, Zakharov, V., and Zarnecki, J. C.

Abstract

The Rosetta probe, orbiting Jupiter-family comet 67P/Churyumov-Gerasimenko, has been detecting individual dust particles of mass larger than 10(-10) kg by means of the GIADA dust collector and the OSIRIS Wide Angle Camera and Narrow Angle Camera since 2014 August and will continue until 2016 September. Detections of single dust particles allow us to estimate the anisotropic dust flux from 67P, infer the dust loss rate and size distribution at the surface of the sunlit nucleus, and see whether the dust size distribution of 67P evolves in time. The velocity of the Rosetta orbiter, relative to 67P, is much lower than the dust velocity measured by GIADA, thus dust counts when GIADA is nadir-pointing will directly provide the dust flux. In OSIRIS observations, the dust flux is derived from the measurement of the dust space density close to the spacecraft. Under the assumption of radial expansion of the dust, observations in the nadir direction provide the distance of the particles by measuring their trail length, with a parallax baseline determined by the motion of the spacecraft. The dust size distribution at sizes > 1 mm observed by OSIRIS is consistent with a differential power index of -4, which was derived from models of 67P's trail. At sizes <1 mm, the size distribution observed by GIADA shows a strong time evolution, with a differential power index drifting from -2 beyond 2 au to -3.7 at perihelion, in agreement with the evolution derived from coma and tail models based on ground-based data. The refractory-to-water mass ratio of the nucleus is close to six during the entire inbound orbit and at perihelion.

Published
2016
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25. 67P/C-G inner coma dust properties from 2.2 au inbound to 2.0 au outbound to the Sun

Author

Della Corte, V., primary, Rotundi, A., additional, Fulle, M., additional, Ivanovski, S., additional, Green, S. F., additional, Rietmeijer, F. J. M., additional, Colangeli, L., additional, Palumbo, P., additional, Sordini, R., additional, Ferrari, M., additional, Accolla, M., additional, Zakharov, V., additional, Mazzotta Epifani, E., additional, Weissman, P., additional, Gruen, E., additional, Lopez-Moreno, J. J., additional, Rodriguez, J., additional, Bussoletti, E., additional, Crifo, J. F., additional, Esposito, F., additional, Lamy, P. L., additional, McDonnell, J. A. M., additional, Mennella, V., additional, Molina, A., additional, Morales, R., additional, Moreno, F., additional, Palomba, E., additional, Perrin, J. M., additional, Rodrigo, R., additional, Zarnecki, J. C., additional, Cosi, M., additional, Giovane, F., additional, Gustafson, B., additional, Ortiz, J. L., additional, Jeronimo, J. M., additional, Leese, M. R., additional, Herranz, M., additional, Liuzzi, V., additional, and Lopez-Jimenez, A. C., additional

Published
2016
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26. Comet 67P/Churyumov–Gerasimenko preserved the pebbles that formed planetesimals

Author

Fulle, Marco, primary, Della Corte, V., additional, Rotundi, A., additional, Rietmeijer, F. J. M., additional, Green, S. F., additional, Weissman, P., additional, Accolla, M., additional, Colangeli, L., additional, Ferrari, M., additional, Ivanovski, S., additional, Lopez-Moreno, J. J., additional, Epifani, E. Mazzotta, additional, Morales, R., additional, Ortiz, J. L., additional, Palomba, E., additional, Palumbo, P., additional, Rodriguez, J., additional, Sordini, R., additional, and Zakharov, V., additional

Published
2016
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27. EVOLUTION OF THE DUST SIZE DISTRIBUTION OF COMET 67P/CHURYUMOV–GERASIMENKO FROM 2.2 au TO PERIHELION

Author

Fulle, M., primary, Marzari, F., additional, Della Corte, V., additional, Fornasier, S., additional, Sierks, H., additional, Rotundi, A., additional, Barbieri, C., additional, Lamy, P. L., additional, Rodrigo, R., additional, Koschny, D., additional, Rickman, H., additional, Keller, H. U., additional, López-Moreno, J. J., additional, Accolla, M., additional, Agarwal, J., additional, A’Hearn, M. F., additional, Altobelli, N., additional, Barucci, M. A., additional, Bertaux, J.-L., additional, Bertini, I., additional, Bodewits, D., additional, Bussoletti, E., additional, Colangeli, L., additional, Cosi, M., additional, Cremonese, G., additional, Crifo, J.-F., additional, Da Deppo, V., additional, Davidsson, B., additional, Debei, S., additional, De Cecco, M., additional, Esposito, F., additional, Ferrari, M., additional, Giovane, F., additional, Gustafson, B., additional, Green, S. F., additional, Groussin, O., additional, Grün, E., additional, Gutierrez, P., additional, Güttler, C., additional, Herranz, M. L., additional, Hviid, S. F., additional, Ip, W., additional, Ivanovski, S. L., additional, Jerónimo, J. M., additional, Jorda, L., additional, Knollenberg, J., additional, Kramm, R., additional, Kührt, E., additional, Küppers, M., additional, Lara, L., additional, Lazzarin, M., additional, Leese, M. R., additional, López-Jiménez, A. C., additional, Lucarelli, F., additional, Mazzotta Epifani, E., additional, McDonnell, J. A. M., additional, Mennella, V., additional, Molina, A., additional, Morales, R., additional, Moreno, F., additional, Mottola, S., additional, Naletto, G., additional, Oklay, N., additional, Ortiz, J. L., additional, Palomba, E., additional, Palumbo, P., additional, Perrin, J.-M., additional, Rietmeijer, F. J. M., additional, Rodríguez, J., additional, Sordini, R., additional, Thomas, N., additional, Tubiana, C., additional, Vincent, J.-B., additional, Weissman, P., additional, Wenzel, K.-P., additional, Zakharov, V., additional, and Zarnecki, J. C., additional

Published
2016
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28. Chemical desorption and diffusive dust chemistry

Author

Dulieu, F, Pirronello, Valerio, Minissale, M, Congiu, E, Baouche, S, Chaabouni, H, Moudens, A, Accolla, M, Cazaux, S, Manico', Giulio, and Kapteyn Astronomical Institute

Abstract

In molecular clouds, gaseous species can accrete efficiently on the cold surfaces of dust grains. As for radical-radical reactions, the surface of the grains acts as a third body, and changes dramatically the efficiency of the reactions (i.e., H2 formation), or lowers considerably the barrier to formation (i.e., H2O synthesis) in comparison with gas phase reaction processes. These properties make dust grains efficient catalytic templates. However, the chemical role of dust grains depends on the diffusive properties of the reactive partners. Over the last years, we have developed experimental tools and methods to explore the chemistry occurring on cold (6-50K) surfaces. We have obtained some hints about the diffusivity of H on amorphous ice, and studied in detail the diffusion of O atoms. The latter species appears to have a hopping rate in the range 0.01-100 hops/sec. The diffusion rate of O atoms is dependent on the surface morphology and on the surface temperature. The diffusion law is compatible with a diffusion dominated by quantum tunnelling rather than classical thermal hopping. Using H, O, N atoms and, indirectly, OH and HCO radicals, we have begun to explore many chemical reactive networks. In this presentation, I will focus on the formation of H2O and CO2, and will propose many possible formation routes to obtain these chemical traps. The molecules formed on surfaces have a certain probability of desorbing upon their formation. This non-thermal desorption mechanism, or chemical desorption, has been proposed to explain why some molecules can be detected in the gas phase of those region where they were believed to be part of the icy mantles covering dust grains. We have shown that this process can be very efficient, but is very sensitive to the substrate and the surroundings of the reaction site, is dependent on the kind of molecule formed and its chemical pathway. In my presentation I will present how the surface coverage and the type of reaction can play a major role in the chemical desorption process. I will discuss of possible key parameters that rule this process.

Published
2014

35. GIADA: State of Health during the Seven Years of Rosetta Cruise

Author

Rotundi, Alessandra, Corte, V. Della, Bussoletti, Ezio, Colangeli, L., Palumbo, Pasquale, Lopez–moreno, J. J., Rodriguez, J., Accolla, M., Aronica, A., Esposito, F., Ferrari, M., Ivanovski, M. Fulle S., Jeronimo, J. M., Jimenez, A. Lopez, Lucarelli, F., Epifani, E. Mazzotta, Mennella, V., Morales, R., Moreno, F., Palomba, E., and Sordini, R.

Published
2012

36. Exploring cometary dust. In laboratory: Stardust/NASA and DUSTER/ASI. In situ: Rosetta/ESA

Author

Rotundi, Alessandra, DELLA CORTE, Vincenzo, Accolla, M., Baratta, G. A., Borg, J., Brucato, J. R., Brunetto, R., Dartois, E., D’Hendecourt, L., Djouadi, Z., Ferrari, M., Fulle, M., Galluzzi, V., Ivanovski, S., Lucarelli, F., Mazzotta Epifani, E., Merouane, S., Mennella, V., Palumbo, M. E., Palumbo, Pasquale, Rietmeijer, F. J. M., and Sordini, R.

Published
2012

39. GIADA: shining a light on the monitoring of the comet dust production from the nucleus of 67P/Churyumov-Gerasimenko

Author

Della Corte, V., primary, Rotundi, A., additional, Fulle, M., additional, Gruen, E., additional, Weissman, P., additional, Sordini, R., additional, Ferrari, M., additional, Ivanovski, S., additional, Lucarelli, F., additional, Accolla, M., additional, Zakharov, V., additional, Mazzotta Epifani, E., additional, Lopez-Moreno, J. J., additional, Rodriguez, J., additional, Colangeli, L., additional, Palumbo, P., additional, Bussoletti, E., additional, Crifo, J. F., additional, Esposito, F., additional, Green, S. F., additional, Lamy, P. L., additional, McDonnell, J. A. M., additional, Mennella, V., additional, Molina, A., additional, Morales, R., additional, Moreno, F., additional, Ortiz, J. L., additional, Palomba, E., additional, Perrin, J. M., additional, Rietmeijer, F. J. M., additional, Rodrigo, R., additional, Zarnecki, J. C., additional, Cosi, M., additional, Giovane, F., additional, Gustafson, B., additional, Herranz, M. L., additional, Jeronimo, J. M., additional, Leese, M. R., additional, Lopez-Jimenez, A. C., additional, and Altobelli, N., additional

Published
2015
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40. DENSITY AND CHARGE OF PRISTINE FLUFFY PARTICLES FROM COMET 67P/CHURYUMOV–GERASIMENKO

Author

Fulle, M., primary, Corte, V. Della, additional, Rotundi, A., additional, Weissman, P., additional, Juhasz, A., additional, Szego, K., additional, Sordini, R., additional, Ferrari, M., additional, Ivanovski, S., additional, Lucarelli, F., additional, Accolla, M., additional, Merouane, S., additional, Zakharov, V., additional, Epifani, E. Mazzotta, additional, Moreno, J. J. López-, additional, Rodríguez, J., additional, Colangeli, L., additional, Palumbo, P., additional, Grün, E., additional, Hilchenbach, M., additional, Bussoletti, E., additional, Esposito, F., additional, Green, S. F., additional, Lamy, P. L., additional, McDonnell, J. A. M., additional, Mennella, V., additional, Molina, A., additional, Morales, R., additional, Moreno, F., additional, Ortiz, J. L., additional, Palomba, E., additional, Rodrigo, R., additional, Zarnecki, J. C., additional, Cosi, M., additional, Giovane, F., additional, Gustafson, B., additional, Herranz, M. L., additional, Jerónimo, J. M., additional, Leese, M. R., additional, Jiménez, A. C. López-, additional, and Altobelli, N., additional

Published
2015
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43. GIADA: ITS STATUS AFTER THE ROSETTA CRUISE PHASE AND ON-GROUND ACTIVITY IN SUPPORT OF THE ENCOUNTER WITH COMET 67P/CHURYUMOV-GERASIMENKO

Author

DELLA CORTE, V., primary, ROTUNDI, A., additional, ACCOLLA, M., additional, SORDINI, R., additional, PALUMBO, P., additional, COLANGELI, L., additional, LOPEZ–MORENO, J. J., additional, RODRIGUEZ, J., additional, RIETMEIJER, F. J. M., additional, FERRARI, M., additional, LUCARELLI, F., additional, MAZZOTTA EPIFANI, E., additional, IVANOVSKI, S., additional, ARONICA, A., additional, COSI, M., additional, BUSSOLETTI, E., additional, CRIFO, J. F., additional, ESPOSITO, F., additional, FULLE, M., additional, GREEN, S. F., additional, GRUEN, E., additional, HERRANZ, M. L., additional, JERONIMO, J. M., additional, LAMY, P., additional, LOPEZ JIMENEZ, A., additional, McDONNELL, J. A. M., additional, MENNELLA, V., additional, MOLINA, A., additional, MORALES, R., additional, MORENO, F., additional, PALOMBA, E., additional, PERRIN, J. M., additional, RODRIGO, R., additional, WEISSMAN, P., additional, ZAKHAROV, V., additional, and ZARNECKI, J. C., additional

Published
2014
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44. Quantum Tunneling of Oxygen Atoms on Very Cold Surfaces

Author

Minissale, M., primary, Congiu, E., additional, Baouche, S., additional, Chaabouni, H., additional, Moudens, A., additional, Dulieu, F., additional, Accolla, M., additional, Cazaux, S., additional, Manicó, G., additional, and Pirronello, V., additional

Published
2013
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