Examinando por Autor "Joblin, Christine"

Mostrando 1 - 5 de 5

Acceso Abierto
PDRs4All VIII: Mid-IR emission line inventory of the Orion Bar
(EDP Sciences, 2024-04-04) Van De Putte, Dries; Meshaka, Raphael; Trahin, Boris; Habart, Emilie; Peeters, Els; Berné, Olivier; Alarcón, Felipe; Canin, Amélie; Chown, Ryan; Schroetter, Llane; Sidhu, Ameek; Boersma, Christiaan; Bron, Emeric; Dartois, Emmanuel; Goicoechea, Javier R.; Gordon, Karl D.; Onaka, Takashi; Tielens, Alexander G. G. M.; Verstraete, Laurent; Wolfire, Mark G.; Abergel, Alain; Bergin, Edwin A.; Bernard-Salas, Jeronimo; Cami, Jan; Cuadrado, Sara; Dicken, Daniel; Elyajouri, Meriem; Fuente, Asuncion; Joblin, Christine; Baria, Khan; Lacinbala, Ozan; Languignon, David; Le Gal, Romane; Maragkoudakis, Alexandros; Okada, Yoko; Pasquini, Sofia; Pound, Marc W.; Robberto, Massimo; Röllig, Markus; Schefter, Bethany; Schirmer, Thiébaut; Tabone, Benoit; Vicente, Sílvia; Zannese, Marion; Colgan, Sean W. J.; He, Jinhua; Rouillé, Gaël; Togi, Aditya; Aleman, Isabel; Auchettl, Rebecca; Baratta, Giuseppe Antonio; Bejaoui, Salma; Bera, Partha P.; Black, John H.; Boulanger, Francois; Bouwman, Jordy; Brandl, Bernhard; Brechignac, Philippe; Brünken, Sandra; Buragohain, Mridusmita; Burkhardt, Andrew; Candian, Alessandra; Cazaux, Stéphanie; Cernicharo, J.; Chabot, Marin; Chakraborty, Shubhadip; Champion, Jason; Cooke, Ilsa R.; Coutens, Audrey; Cox, Nick L. J.; Demyk, Karine; Donovan Meyer, Jennifer; Foschino, Sacha; García-Lario, Pedro; Gerin, Maryvonne; Gottlieb, Carl A.; Guillard, Pierre; Gusdorf, Antoine; Hartigan, Patrick; Herbst, Eric; Hornekaer, Liv; Issa, Lina; Jäger, Cornelia; Janot-Pacheco, Eduardo; Kannavou, Olga; Kaufman, Michael; Kemper, Francisca ; Kendrew, Sarah; Kirsanova, Maria S. ; Klaassen, Pamela; Kwok, Sun; Labiano, Alvaro; Lai, Thomas S.-Y.; Le Floch, Bertrand; Le Petit, Franck; Li, Aigen; Linz, Hendrik; Mackie, Cameron J.; Madden, Suzanne C.; Mascetti, Joëlle; McGuire, Brett A.; Merino, Pablo; Micelotta, Elisabetta R.; MorseJon A. ,; Mulas, Giacomo; Neelamkodan, Naslim; Ohsawa, Ryou; Omont, Alain; Paladini, Roberta; Palumbo, Maria Elisabetta; Pathak, Amit; Pendleton, Yvonne J.; Petrignani, Annemieke; Pino, Thomas; Puga, Elena; Rangwala, Naseem; Rapacioli, Mathias; Rho, Jeonghee; Ricca, Alessandra; Roman-Duval, Julia; Roser, Joseph; Roueff, Evelyne; Salama, Farid; Sales, Dinalva A.; Sandstrom, Karin; Sarre, Peter; Sciamma-O’Brien, Ella; Sellgren, Kris; Shenoy, Sachindev S.; Teyssier, David; Thomas, Richard D.; Witt, Adolf N.; Wootten, Alwyn; Ysard, Nathalie; Zettergren, Henning; Zhang, Yong; Zhang, Ziwei E.; Zhen, Junfeng; Chinese Academy of Sciences (CAS); Space Telescope Science Institute (STScI); Science and Engineering Research Board (SERB); Ministerio de Ciencia e Innovación (MICINN); Japan Society for the Promotion of Science (JSPS); European Commission (EC); Deutsche Forschungsgemeinschaft (DFG); Ames Research Center, NASA (ARC); Banaras Hindu University (BHU)
Context. Mid-infrared emission features are important probes of the properties of ionized gas and hot or warm molecular gas, which are difficult to probe at other wavelengths. The Orion Bar photodissociation region (PDR) is a bright, nearby, and frequently studied target containing large amounts of gas under these conditions. Under the “PDRs4All” Early Release Science Program for JWST, a part of the Orion Bar was observed with MIRI integral field unit (IFU) spectroscopy, and these high-sensitivity IR spectroscopic images of very high angular resolution (0.2″) provide a rich observational inventory of the mid-infrared (MIR) emission lines, while resolving the H II region, the ionization front, and multiple dissociation fronts. Aims. We list, identify, and measure the most prominent gas emission lines in the Orion Bar using the new MIRI IFU data. An initial analysis summarizes the physical conditions of the gas and demonstrates the potential of these new data and future IFU observations with JWST. Methods. The MIRI IFU mosaic spatially resolves the substructure of the PDR, its footprint cutting perpendicularly across the ionization front and three dissociation fronts. We performed an up-to-date data reduction, and extracted five spectra that represent the ionized, atomic, and molecular gas layers. We identified the observed lines through a comparison with theoretical line lists derived from atomic data and simulated PDR models. The identified species and transitions are summarized in the main table of this work, with measurements of the line intensities and central wavelengths. Results. We identified around 100 lines and report an additional 18 lines that remain unidentified. The majority consists of H I recombination lines arising from the ionized gas layer bordering the PDR. The H I line ratios are well matched by emissivity coefficients from H recombination theory, but deviate by up to 10% because of contamination by He I lines. We report the observed emission lines of various ionization stages of Ne, P, S, Cl, Ar, Fe, and Ni. We show how the Ne III/Ne II, S IV/S III, and Ar III/Ar II ratios trace the conditions in the ionized layer bordering the PDR, while Fe III/Fe II and Ni III/Ni II exhibit a different behavior, as there are significant contributions to Fe II and Ni II from the neutral PDR gas. We observe the pure-rotational H2 lines in the vibrational ground state from 0–0 S(1) to 0–0 S (8), and in the first vibrationally excited state from 1–1 S (5) to 1–1 S(9). We derive H2 excitation diagrams, and for the three observed dissociation fronts, the rotational excitation can be approximated with one thermal (~700 K) component representative of an average gas temperature, and one nonthermal component (~2700 K) probing the effect of UV pumping. We compare these results to an existing model of the Orion Bar PDR, and find that the predicted excitation matches the data qualitatively, while adjustments to the parameters of the PDR model are required to reproduce the intensity of the 0–0 S (6) to S (8) lines.
Acceso Abierto
Precisely controlled fabrication, manipulation and in-situ analysis of Cu based nanoparticles
(Nature, 2018-05-08) Martínez, Lidia; Lauwaet, K.; Santoro, G.; Sobrado, J. M.; Peláez, R. J.; Herrero, V. J.; Tanarro, I.; Ellis, G. J.; Cernicharo, J.; Joblin, Christine; Huttel, Y.; Martín Gago, J. A.; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Economía y Competitividad (MINECO); European Commission (EC); Agencia Estatal de Investigación (AEI)
The increasing demand for nanostructured materials is mainly motivated by their key role in a wide variety of technologically relevant fields such as biomedicine, green sustainable energy or catalysis. We have succeeded to scale-up a type of gas aggregation source, called a multiple ion cluster source, for the generation of complex, ultra-pure nanoparticles made of different materials. The high production rates achieved (tens of g/day) for this kind of gas aggregation sources, and the inherent ability to control the structure of the nanoparticles in a controlled environment, make this equipment appealing for industrial purposes, a highly coveted aspect since the introduction of this type of sources. Furthermore, our innovative UHV experimental station also includes in-flight manipulation and processing capabilities by annealing, acceleration, or interaction with background gases along with in-situ characterization of the clusters and nanoparticles fabricated. As an example to demonstrate some of the capabilities of this new equipment, herein we present the fabrication of copper nanoparticles and their processing, including the controlled oxidation (from Cu0 to CuO through Cu2O, and their mixtures) at different stages in the machine.
Restringido
Prevalence of non-aromatic carbonaceous molecules in the inner regions of circumstellar envelopes
(Nature, 2019-10-21) Martínez, Lidia; Santoro, G.; Merino, P.; Accolla, M.; Lauwaet, K.; Sobrado, J. M.; Sabbah, H.; Peláez, R. J.; Herrero, V. J.; Tanarro, I.; Agúndez, Marcelino; Martín Jiménez, Alberto; Otero, Roberto; Ellis, G. J.; Joblin, Christine; Cernicharo, J.; Martín Gago, J. A.; Instituto Nacional de Técnica Aeroespacial (INTA); European Commission (EC); Agencia Estatal de Investigación (AEI)
Evolved stars are foundries of chemical complexity, gas and dust that provide the building blocks of planets and life, and dust nucleation first occurs in their photosphere. The circumstellar regions enveloping these stars, despite their importance, remain hidden to many observations, and dust formation processes are therefore still poorly understood. Laboratory astrophysics provides complementary routes to unveil these chemical processes, but most experiments rely on combustion or plasma decomposition of molecular precursors under physical conditions far removed from those in space. To reproduce and characterize the bottom-up dust formation process, we have built an ultra-high vacuum machine combining atomic gas aggregation with advanced in situ characterization techniques. We show that carbonaceous dust analogues that formed from low-pressure gas-phase condensation of carbon atoms in a hydrogen atmosphere, in a ratio of carbon to molecular hydrogen similar to that reported for evolved stars, lead to the formation of amorphous carbon nanograins and aliphatic carbon clusters. Aromatic species and fullerenes do not form effectively under these conditions, raising implications for a revision of the chemical mechanisms taking place in circumstellar envelopes.
Acceso Abierto
The Chemistry of Cosmic Dust Analogs from C, C2, and C2H2 in C-rich Circumstellar Envelopes
(The Institute of Physics (IOP), 2020-06-02) Santoro, G.; Martínez, Lidia; Lauwaet, K.; Accolla, M.; Tajuelo Castilla, G.; Merino, Pablo; Sobrado, J. M.; Peláez, R. J.; Herrero, V. J.; Tanarro, I.; Mayoral, Á.; Agúndez, Marcelino; Sabbah, H.; Joblin, Christine; Cernicharo, J.; Martín Gago, J. A.; European Commission (EC); Comunidad de Madrid; Ministerio de Economía y Competitividad (MINECO); Santorio, G. [0000-0003-4751-2209]; Accolla, M. [0000-0002-9509-5967]; Agúndez, M. [0000-0003-3248-3564]; Sabbah, H. [0000-0001-5722-4388]; Joblin, C. [0000-0003-1561-6118]; Cernicharo, J. [0000-0002-3518-2524]; Martín Gago, J. M. [0000-0003-2663-491X]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Interstellar carbonaceous dust is mainly formed in the innermost regions of circumstellar envelopes around carbon-rich asymptotic giant branch stars (AGBs). In these highly chemically stratified regions, atomic and diatomic carbon, along with acetylene, are the most abundant species after H and CO. In a previous study, we addressed the chemistry of carbon (C and C) with H showing that acetylene and aliphatic species form efficiently in the dust formation region of carbon-rich AGBs whereas aromatics do not. Still, acetylene is known to be a key ingredient in the formation of linear polyacetylenic chains, benzene, and polycyclic aromatic hydrocarbons (PAHs), as shown by previous experiments. However, these experiments have not considered the chemistry of carbon (C and C) with CH. In this work, by employing a sufficient amount of acetylene, we investigate its gas-phase interaction with atomic and diatomic carbon. We show that the chemistry involved produces linear polyacetylenic chains, benzene, and other PAHs, which are observed with high abundances in the early evolutionary phase of planetary nebulae. More importantly, we have found a nonnegligible amount of pure and hydrogenated carbon clusters as well as aromatics with aliphatic substitutions, both being a direct consequence of the addition of atomic carbon. The incorporation of alkyl substituents into aromatics can be rationalized by a mechanism involving hydrogen abstraction followed by methyl addition. All the species detected in the gas phase are incorporated into nanometric-sized dust analogs, which consist of a complex mixture of sp, sp, and sp hydrocarbons with amorphous morphology.
Acceso Abierto
Using radio astronomical receivers for molecular spectroscopic characterization in astrochemical laboratory simulations: A proof of concept
(EDP Science, 2017-12-22) Tanarro, I.; Alemán, Belén; De Vicente, P.; Gallego, J. D.; Pardo, Juan R.; Santoro, G.; Lauwaet, K.; Tercero, Felix; Díaz Pulido, A.; Moreno, E.; Agúndez, Marcelino; Goicoechea, Javier R.; Sobrado, J. M.; López, J. A.; Martínez, Lidia; Doménech, Jose Luis; Herrero, V. J.; Hernández, J. M.; Peláez, R. J.; López Pérez, Jose A.; Gómez González, J.; Alonso, J. L.; Jiménez, Elena; Teyssier, D.; Makasheva, Kremena; Castellanos, Marcelo; Joblin, Christine; Martín Gago, J. A.; Cernicharo, J.; Ministerio de Economía y Competitividad (MINECO)
We present a proof of concept on the coupling of radio astronomical receivers and spectrometers with chemical reactors and the performances of the resulting setup for spectroscopy and chemical simulations in laboratory astrophysics. Several experiments including cold plasma generation and UV photochemistry were performed in a 40 cm long gas cell placed in the beam path of the Aries 40 m radio telescope receivers operating in the 41–49 GHz frequency range interfaced with fast Fourier transform spectrometers providing 2 GHz bandwidth and 38 kHz resolution. The impedance matching of the cell windows has been studied using different materials. The choice of the material and its thickness was critical to obtain a sensitivity identical to that of standard radio astronomical observations. Spectroscopic signals arising from very low partial pressures of CH3OH, CH3CH2OH, HCOOH, OCS, CS, SO2 (<10-3 mbar) were detected in a few seconds. Fast data acquisition was achieved allowing for kinetic measurements in fragmentation experiments using electron impact or UV irradiation. Time evolution of chemical reactions involving OCS, O2 and CS2 was also observed demonstrating that reactive species, such as CS, can be maintained with high abundance in the gas phase during these experiments.