Showing papers by "Maria Elisabetta Palumbo published in 2022"
TL;DR: In this article , the Orion Bar image was used to identify key photo-dissociation regions (PDRs) characteristics in the James Webb Space Telescope (JWST) observations, which will serve to benchmark PDR models and extend them into the JWST era.
Abstract: Massive stars disrupt their natal molecular cloud material through radiative and mechanical feedback processes. These processes have profound effects on the evolution of interstellar matter in our Galaxy and throughout the universe, from the era of vigorous star formation at redshifts of 1–3 to the present day. The dominant feedback processes can be probed by observations of the Photo-Dissociation Regions (PDRs) where the far-ultraviolet photons of massive stars create warm regions of gas and dust in the neutral atomic and molecular gas. PDR emission provides a unique tool to study in detail the physical and chemical processes that are relevant for most of the mass in inter- and circumstellar media including diffuse clouds, proto-planetary disks, and molecular cloud surfaces, globules, planetary nebulae, and star-forming regions. PDR emission dominates the infrared (IR) spectra of star-forming galaxies. Most of the Galactic and extragalactic observations obtained with the James Webb Space Telescope (JWST) will therefore arise in PDR emission. In this paper we present an Early Release Science program using the MIRI, NIRSpec, and NIRCam instruments dedicated to the observations of an emblematic and nearby PDR: the Orion Bar. These early JWST observations will provide template data sets designed to identify key PDR characteristics in JWST observations. These data will serve to benchmark PDR models and extend them into the JWST era. We also present the Science-Enabling products that we will provide to the community. These template data sets and Science-Enabling products will guide the preparation of future proposals on star-forming regions in our Galaxy and beyond and will facilitate data analysis and interpretation of forthcoming JWST observations.
17 citations
TL;DR: Galiano et al. as discussed by the authors performed an investigation as part of SIMULATION OF SPACE WEATHERING on AIRLESS BODIES OF SOLAR Systems. But their work was limited to the simulation of space weather.
Abstract: INVESTIGATION AS PART OF SIMULATION OF SPACE WEATHERING ON AIRLESS BODIES OF SOLAR SYSTEM. A. Galiano, F. Dirri, M. Ferrari, S. Stefani, G. Piccioni, M.E. Palumbo, C. Scirè Scappuzzo, G. Baratta, C. Carli, A. Musolino, INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy (anna.galiano@inaf.it), OACT-INAF, Osservatorio Astrofisico di Catania, Italy, Università di Napoli “Parthenope”, DIST, Centro Direzionale Isola C4, I-80143 Naples, Italy.
TL;DR: In this article , the authors compared the infrared spectra of laboratory-made refractory organic residues to spectra from meteorites and interplanetary dust particles, and confirmed the detection of water, nitriles, hydrocarbons, and carbonates in extraterrestrial particles and link the formation location of the particles in the outer regions of the solar nebula.
Abstract: The origin of organic compounds detected in meteorites and comets, some of which could have served as precursors of life on Earth, remains an open question. The aim of the present study is to make one more step in revealing the nature and composition of organic materials of extraterrestrial particles by comparing infrared spectra of laboratory-made refractory organic residues to spectra of cometary particles returned by the Stardust mission, interplanetary dust particles, and meteorites. Our results reinforce the idea of a pathway for the formation of refractory organics through energetic and thermal processing of molecular ices in the solar nebula. There is also the possibility that some of the organic material had formed already in the parental molecular cloud before it entered the solar nebula. The majority of the IR “organic” bands of the studied extraterrestrial particles can be reproduced in the spectra of the laboratory organic residues. We confirm the detection of water, nitriles, hydrocarbons, and carbonates in extraterrestrial particles and link it to the formation location of the particles in the outer regions of the solar nebula. To clarify the genesis of the species, high-sensitivity observations in combination with laboratory measurements like those presented in this paper are needed. Thus, this study presents one more piece of the puzzle of the origin of water and organic compounds on Earth and motivation for future collaborative laboratory and observational projects.
TL;DR: In this article , the effects of simulated solar wind on a polymeric material, polymethyl methacrylate (PMMA), was produced through radical bulk polymerization, and the PMMA was subjected to proton beam bombardment at different fluences and in a high vacuum environment, with structural changes monitored through real-time FT-IR analysis.
Abstract: Space exploration missions are currently becoming more frequent, due to the ambition for space colonization in sight of strengthening terrestrial technologies and extracting new raw materials and/or resources. In this field, the study of the materials’ behaviour when exposed to space conditions is fundamental for enabling the use of currently existing materials or the development of new materials suitable for application in extra-terrestrial environments. In particular, the versatility of polymers renders them suitable for advanced applications, but the effects of space radiation on these materials are not yet fully understood. Here, to shed light on the effects of simulated solar wind on a polymeric material, polymethyl methacrylate (PMMA) was produced through radical bulk polymerization. The PMMA in the form of a thin film was subjected to proton beam bombardment at different fluences and in a high vacuum environment, with structural changes monitored through real-time FT-IR analysis. The structure of the residual material was investigated through MALDI-TOF mass spectrometry and 1H-NMR spectroscopy. The collected data allowed us to hypothesize the structural modifications of the PMMA and the related mechanisms.
TL;DR: In this paper , the role of ion bombardment in the formation of formaldehyde (H 2 CO) and acetaldehyde (CH 3 CHO), which are observed in the interstellar medium and in comets, and which are thought to be the precursors of more complex compounds such as hexamethylenetetramine (HMT), was investigated.
Abstract: Context. Cosmic rays and solar energetic particles induce changes in the composition of compounds frozen onto dust grains in the interstellar medium (ISM), in comets, and on the surfaces of atmosphere-less small bodies in the outer Solar System. This induces the destruction of pristine compounds and triggers the formation of various species, including the precursors of complex organics. Aims. We investigate the role of energetic ions in the formation of formaldehyde (H 2 CO) and acetaldehyde (CH 3 CHO), which are observed in the ISM and in comets, and which are thought to be the precursors of more complex compounds such as hexamethylenetetramine (HMT), which is found in carbonaceous chondrites and in laboratory samples produced after the irradiation and warm-up of astrophysical ices. Methods. We performed ion irradiation of water, methanol, and ammonia mixtures at 14–18 K. We bombarded frozen films with 40–200 keV H + that simulate solar energetic particles and low-energy cosmic rays. Samples were analysed by infrared transmission spectroscopy. Results. Among other molecules, we observe the formation of H 2 CO and CH 3 CHO, and we find that their abundance depends on the dose and on the stoichiometry of the mixtures. We find that the H 2 CO abundance reaches the highest value after a dose of 10 eV/16u and then it decreases as the dose increases. Conclusions. The data suggest that surfaces exposed to high doses are depleted in H 2 CO. This explains why the amount of HMT in organic residues and that formed after irradiation of ices depends on the dose deposited in the ice. Because the H 2 CO abundance decreases at doses higher than 10 eV/16u, a lower quantity of H 2 CO is available to form HMT during the subsequent warm-up. The H 2 CO abundances caused by ion bombardment are insufficient to explain the ISM abundances, but ion bombardment can account for the abundance of CH 3 CHO towards the ISM and comets.