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Articoli di riviste sul tema "Interstellar matter"

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Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 25 maggio 2024

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1

Lequeux, J., J. S. Mathis, K. S. de Boer, S. D’Odorico, B. G. Elmegreen, D. Flower, H. Habing et al. "34. Interstellar Matter (Matiere Interstellaire)". Transactions of the International Astronomical Union 20, n. 01 (1988): 423–71. http://dx.doi.org/10.1017/s0251107x0000732x.

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The previous report started with optimistic remarks about the increasing importance of the study of interstellar matter in astronomy. This trend has largely been confirmed in the 1985-87 period and it is clear that the subject of our Commission is one of the most active fields of astronomical research. This is also shown by the rapidly growing number of members and by the constitution of new working groups. The major new event in the period has undoubtly been the availability of IRAS data.

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2

Habing, H. J., E. Falgarone, D. Flower, P. G. Martin, M. R. Rosa, T. Lozinskaya e M. Dopita. "34 Interstellar Matter: Matiere Interstellaire". Transactions of the International Astronomical Union 22, n. 1 (1994): 367–97. http://dx.doi.org/10.1017/s0251107x00008117.

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3

Dopita, Michael A., Rafael Bachiller, Michael Burton, John Dyson, Debra Elmegreen, Thomas Henning, Sun Kwok et al. "Division VI: Interstellar Matter: (Matière Interstellaire)". Transactions of the International Astronomical Union 24, n. 1 (2000): 277–80. http://dx.doi.org/10.1017/s0251107x00003175.

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Division VI of the International Astronomical Union deals with Interstellar Matter, and incorporates Commission 34. It gathers astronomers studying the diffuse matter in space between the stars, ranging from primordial intergalactic clouds via dust and neutral and ionised gas in galaxies to the densest molecular clouds and the processes by which stars are formed. There are approximately 730 members. The working groups in Planetary Nebulae and Cosmochemistry have served us well in organising periodic seminars in these subject areas. However, the Organising Committee has recognised that other developing areas of the ISM are not properly represented in the current organisation. In January 1997, the Division formed a new ISM working group on Star Forming Regions including cross-divisional representation to monitor progress in their fields and to help develop proposals for future IAU Symposia or Colloquia. In the future, especially in view of the rapid developments in spaceborne X-ray and IR astronomy, Division VI also hopes to form other working groups on the Hot ISM and the Extragalactic ISM.

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4

Reipurth, Bo. "Division VI: Interstellar Matter (Matiere Interstellaire)". Transactions of the International Astronomical Union 25, n. 2 (2007): 157–58. http://dx.doi.org/10.1017/s0251107x00026729.

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5

Reipurth, Bo, Rafael Bachiller, John Dyson, José Franco, Thomas Henning, Trung Hua, Sun Kwok et al. "Division VI: Interstellar Matter: (Matiere Interstellaire)". Transactions of the International Astronomical Union 25, n. 1 (2002): 283–86. http://dx.doi.org/10.1017/s0251107x00001577.

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6

Bochkarev, Nikolai G. "Local interstellar matter and interstellar bubbles". Astronomical & Astrophysical Transactions 3, n. 1 (novembre 1992): 3–16. http://dx.doi.org/10.1080/10556799208230534.

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7

Peimbert, M., J. Lequeux, S. D’Odorico, B. G. Elmegreen, E. B. Kostyakova, J. S. Mathis, U. Mebold et al. "34. Interstellar Matter". Transactions of the International Astronomical Union 19, n. 1 (1985): 437–78. http://dx.doi.org/10.1017/s0251107x00006532.

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It has become more evident during the last three years that the study of interstellar matter is paramount to understand the evolution of the universe and its constituents. From observations of the present state of the interstellar medium, in our galaxy, in other galaxies, and between galaxies, it is possible to test theories of: evolution of the universe, formation and evolution of galaxies, formation and evolution of stars and of the evolution of the interstellar medium itself. The amount of information on the interstellar medium that has been gathered during the 1982-1984 period has been very large and the theoretical models that have been ellaborated to explain these observations have been very numerous, these facts show that the subject of our Commission constitutes a very active field of astronomical research.

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8

Dyson, John, Thomas J. Millar, Bo Reipurth, You-Hua Chu, Gary J. Ferland, José Franco, Chon Trung Hua et al. "DIVISION VI: INTERSTELLAR MATTER". Proceedings of the International Astronomical Union 3, T26B (dicembre 2007): 173. http://dx.doi.org/10.1017/s1743921308023971.

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Division VI gathers astronomers studying the diffuse matter in space between stars, ranging from primordial intergalactic clouds, via dust and neutral and ionized gas in galaxies, to the densest molecular clouds and the processes by which stars are formed.

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9

Millar, Thomas J., You Hua Chu, John E. Dyson, Dieter Breitschwerdt, Michael G. Burton, Sylvie Cabrit, Paola Caselli et al. "DIVISION VI: INTERSTELLAR MATTER". Proceedings of the International Astronomical Union 4, T27A (dicembre 2008): 267–72. http://dx.doi.org/10.1017/s1743921308025659.

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10

Dyson, John, Tom Millar, You-Hua Chu, Gary Ferland, Pepe Franco, Trung Hua, Susana Lizano et al. "Division VI: Interstellar Matter". Proceedings of the International Astronomical Union 1, T26A (dicembre 2005): 267–71. http://dx.doi.org/10.1017/s1743921306004662.

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Commission 34 covers diffuse matter in space on scales ranging from the circumstellar to the galactic and intergalactic. As such it has enormous scope and because of this, it alone forms Division VI. Key aspects include star formation, matter around evolved stars, astrochemistry, nebulae, galactic and intergalactic clouds and the multitude of effects of the interaction of stars with their surroundings. Associated with these areas are a huge range of physical and chemical processes including hydrodynamics and magnetohydrodynamics, radiative processes, molecular physics and chemistry, plasma processes and others too numerous to name. These are complemented by an equally huge range of observational studies using practically all space and ground-based instrumentation at nearly all observable wavelengths. A glance at any data-base of publications over the past few years attests to the vigorous state of these studies. The current membership of the Division is around 800. It also has three separate working groups.

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11

Millar, Tom, You-Hua Chu, John Dyson, Dieter Breitschwerdt, Mike Burton, Sylvie Cabrit, Paola Caselli et al. "DIVISION VI: INTERSTELLAR MATTER". Proceedings of the International Astronomical Union 6, T27B (14 maggio 2010): 213–14. http://dx.doi.org/10.1017/s1743921310005132.

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The business meeting of Division VI was held on Monday 10 October 2009. Apologies had been received in advance from D Breitschwerdt, P Caselli, G Ferland, M Juvela, S Lizano, M Rozyczka, V Tóth, M Tsuboi, J Yang and B-C Koo.

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12

Chu, You-Hua, Sun Kwok, Thomas J. Millar, Dieter Breitschwerdt, Michael G. Burton, Sylvie Cabrit, Paola Caselli et al. "DIVISION VI: INTERSTELLAR MATTER". Proceedings of the International Astronomical Union 7, T28A (dicembre 2011): 227–35. http://dx.doi.org/10.1017/s1743921312002864.

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13

LANGER, W. D. "Interstellar Matter: Molecular Astrophysics." Science 232, n. 4757 (20 giugno 1986): 1560. http://dx.doi.org/10.1126/science.232.4757.1560.

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14

Brown, Ronald D. "Prebiotic Matter in Interstellar Molecules". Symposium - International Astronomical Union 112 (1985): 123–37. http://dx.doi.org/10.1017/s0074180900146431.

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With the discovery of the first polyatomic molecules, NH3, H2O and H2CO in 1968/9 there was immediate speculation as to how far biological chemical evolution - from atoms to small carbon compounds of biological significance - could have occurred in the Galaxy. There was also potential conflict with the canonical scientific view of the origin of life, traceable to the production of simple bio-molecules from the influence of energetic atmospheric events on the simple gaseous mixture (CH4, H2, H2O and NH3) presumed to compose the atmosphere of the very young Earth.

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15

Roberts, Morton S. "Interstellar Matter in Globular Clusters". Symposium - International Astronomical Union 126 (1988): 411–22. http://dx.doi.org/10.1017/s0074180900042637.

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“Is there any point to which you would wish to draw my attention?”“To the curious incident of the dog in the night-time.”“The dog did nothing in the night-time.”“That was the curious incident,” remarked Sherlock Holmes.Memoirs of Sherlock HolmesThe source for intracluster matter is seen in various mass loss processes ongoing within clusters and is supported by the theoretical need for mass loss to explain the morphology of cluster colormagnitude diagrams. A variety of techniques ranging from X-ray to radio wavelengths have been employed to search for such matter but with few exceptions has not been found. The amount of material expected to collect between cleansing passages through the galactic plane has variously been estimated at between ∼ 102 and ∼ 103 M⊙. In contrast, observed upper limits for many clusters are well below these values, often > 1 M⊙. The few detections are at levels of ≲10−2 M⊙.

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16

Charnley, S. B., e S. D. Rodgers. "Interstellar Reservoirs of Cometary Matter". Space Science Reviews 138, n. 1-4 (5 marzo 2008): 59–73. http://dx.doi.org/10.1007/s11214-008-9331-6.

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17

Frisch, Priscilla C. "Characteristics of nearby interstellar matter". Space Science Reviews 72, n. 3-4 (maggio 1995): 499–592. http://dx.doi.org/10.1007/bf00749006.

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18

Mezger, P. G. "The Interstellar Radiation Field and Its Interaction with the Interstellar Matter". Symposium - International Astronomical Union 139 (1990): 63–73. http://dx.doi.org/10.1017/s0074180900240400.

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Most stars emit most of their radiation in the wavelength range between the far ultraviolet (FUV) and near-infrared (IR). Eddington (1926) first estimated for the solar vicinity a mean radiation intensity of the interstellar radiation field (ISRF) equivalent to that of blackbody radiation of ~3 K but with a spectral distribution that can be approximated by ~10,000 K blackbody radiation diluted by a factor ≈ 10−14.

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19

Tomisaka, Kohji. "Cycling of the local interstellar matter". Advances in Space Research 6, n. 2 (gennaio 1986): 109–18. http://dx.doi.org/10.1016/0273-1177(86)90392-3.

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20

Frisch, Priscilla C. "Local Interstellar Matter: The Apex Cloud". Astrophysical Journal 593, n. 2 (20 agosto 2003): 868–73. http://dx.doi.org/10.1086/376684.

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21

Krätschmer, Wolfgang. "Fullerenes, Carbon Chains, and Interstellar Matter". Fullerenes, Nanotubes and Carbon Nanostructures 22, n. 1-3 (1 gennaio 2014): 23–34. http://dx.doi.org/10.1080/1536383x.2013.794347.

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22

Srama, Ralf, Thomas Stephan, Eberhard Grün, Norbert Pailer, Anton Kearsley, Amara Graps, Rene Laufer et al. "Sample return of interstellar matter (SARIM)". Experimental Astronomy 23, n. 1 (3 maggio 2008): 303–28. http://dx.doi.org/10.1007/s10686-008-9088-7.

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23

Ehrenfreund, Pascale, e Oliver Botta. "From Interstellar Matter To Comets: A Laboratory View". Highlights of Astronomy 13 (2005): 488–90. http://dx.doi.org/10.1017/s1539299600016385.

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AbstractComets, formed in the cold outer parts of the solar system, provide a record of pristine material from the parent interstellar cloud. The investigation of outgassing curves from bright comets has provided a relationship to the abundances of interstellar ices and gas phase molecules. However, being porous and stratified in various layers of different densities and temperatures, the out-gassing characteristics of comets can not always be directly reconciled with the interstellar composition. This is due to the structure of the nuclear ice component, which contains different coexisting ice phases, clathrates, and trapped gases. Ices, silicates and carbonaceous compounds – studied through astronomical observations and by laboratory simulations – serve as reference material to obtain information on cometary bulk material. A major fraction of cosmic carbon in the interstellar medium, comets and meteorites seems to be incorporated into complex aromatic networks, which are difficult to observe and to identify spectroscopically. However, recent measurements of the macromolecular structure and soluble organic species in carbonaceous meteorites provide a powerful tool to investigate the link of small bodies in the solar system.

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24

Lafon, J.-P. J., e E. Huguet. "Problems of modelization of circumstellar matter out of equilibrium". Symposium - International Astronomical Union 162 (1994): 431–33. http://dx.doi.org/10.1017/s0074180900215593.

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Circumstellar envelopes of young and evolved stars are responsible for many important phenomena concerning the exchange of matter, angular momentum, energy and maybe magnetic field between the core structure of stars and the interstellar medium. In particular, it is through them that matter enriched in heavy elements flows from evolved stars towards the interstellar gas, submitted to complex ordinary chemistry or photochemistry and condensation into solid particles.

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25

Kimura, Hiroshi, Frank Postberg, Nicolas Altobelli e Mario Trieloff. "Organic matter in interstellar dust lost at the approach to the heliosphere". Astronomy & Astrophysics 643 (novembre 2020): A50. http://dx.doi.org/10.1051/0004-6361/201526964.

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Aims. We tackle the conundrums of organic materials missing from interstellar dust when measured inside the Solar System, while undoubtedly existing in the local interstellar cloud (LIC), which surrounds the Solar System. Methods. We present a theoretical argument that organic compounds sublimate almost instantaneously by exothermic reactions, when solar insolation triggers the recombination of free radicals or the rearrangement of carbon bonds in the compounds. Results. It turns out that the triggering temperature lies in the range of 20–50 K by considering that sublimation of organic materials takes place beyond the so-called filtration region of interstellar neutral atoms. We find that in-situ measurements of LIC dust in the Solar System result in an overestimate for the gas-to-dust mass ratio of the LIC, unless the sublimation of organic materials is taken into account. We also find that previous measurements of interstellar pickup ions have determined the total elemental abundances of gas and organic materials, instead of interstellar gas alone. Conclusions. We conclude that LIC organic matter suffers from sublimation en route to the heliosphere, implying that our understanding of LIC dust from space missions is incomplete. Since space missions inside the orbit of Saturn cannot give any information on the organic substances of LIC dust, one must await a future exploration mission to the inner edge of the Oort cloud for a thorough understanding of organic substances in the LIC. Once our model for the sublimation of interstellar organic matter by exothermic chemical reactions of free radicals is confirmed, the hypothesis of panspermia from the diffuse interstellar medium is ruled out.

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26

Boulanger, F. "Physical Processes in the Large Scale ISM from Dust Observations". Symposium - International Astronomical Union 179 (1998): 153–64. http://dx.doi.org/10.1017/s0074180900128475.

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Over the last two decades observations of dust emission in the infrared have played an important role in the development of research on the interstellar medium. The study of the spectral energy distribution has led to the discovery of small dust particles including the large aromatic molecules (PAHs). Infrared sky images have been used to study the structure of interstellar matter, the evolution of dust within the interstellar medium and the star formation efficiency of interstellar clouds.

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27

White, Richard E. "Interstellar Matter near the Pleiades. VI. Evidence for an Interstellar Three‐Body Encounter". Astrophysical Journal Supplement Series 148, n. 2 (ottobre 2003): 487–517. http://dx.doi.org/10.1086/377095.

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28

Mennella, Vito. "Laboratory simulation of the evolution of organic matter in dense interstellar clouds". Proceedings of the International Astronomical Union 4, S251 (febbraio 2008): 459–64. http://dx.doi.org/10.1017/s1743921308022187.

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AbstractLaboratory simulation of interstellar grain processing is a unique tool to better understand the nature and evolution of cosmic dust. In recent years this approach has been crucial to outline a new model of evolution of the aliphatic component of organic matter in the interstellar medium. Here, the results of a recent laboratory research on processing of nano-sized carbon particles by H atoms under simulated dense medium conditions are discussed. The experiments show that the formation of C-H bonds in the aliphatic CH2 and CH3 functional groups does not take place, while the activation of a band at 3.47 μm, due to the C-H stretching vibration of tertiary sp3 carbon atoms, is observed. These results indicate that the assumption about inhibition of aliphatic C-H bond formation in interstellar dense clouds is correct. Moreover, they suggest that carbon grains responsible for the interstellar aliphatic band at 3.4 μm in diffuse regions can contribute to the absorption observed at 3.47 μm in dense clouds.

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29

Carter, D., R. M. Johnstone e A. C. Fabian. "Interstellar matter in the core of M87". Monthly Notices of the Royal Astronomical Society 285, n. 3 (1 marzo 1997): L20—L24. http://dx.doi.org/10.1093/mnras/285.3.l20.

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30

Kim, Dong-Woo, e Silvia Pellegrini. "JD8 - Hot Interstellar Matter in Elliptical Galaxies". Proceedings of the International Astronomical Union 5, H15 (novembre 2009): 269–70. http://dx.doi.org/10.1017/s1743921310009154.

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The physical properties of the hot interstellar matter in elliptical galaxies are directly related with the formation and evolution of elliptical galaxies via star formation episodes, environmental effects such as stripping, infall, and mergers, and growth of super-massive black holes. The recent successful Chandra and XMM-Newton X-ray space missions have provided a large amount of high spatial/spectral resolution observational data on the hot ISM in elliptical galaxies. At the same time, theoretical studies with numerical simulations and analytical modeling of the dynamical and chemical evolution of elliptical galaxies have made a significant progress and start to predict various observable quantities.

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31

Messenger, S. "Interstellar Matter in Meteorites and Interplanetary Dust". Symposium - International Astronomical Union 197 (2000): 527–36. http://dx.doi.org/10.1017/s0074180900165088.

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Meteorites and interplanetary dust particles (IDPs) are primitive solar system materials which contain preserved nebular condensates, circumstellar dust grains and partially preserved molecular cloud matter. The circumstellar dust grains found in meteorites are direct samples of a variety of stars, and provide detailed constraints on models of stellar nucleosynthesis. Hydrogen and nitrogen isotopic anomalies in organic matter in meteorites and IDPs are thought to originate from chemical processes in a presolar molecular cloud. This material is better preserved, but less well characterized among IDPs.

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32

Jura, M. "Cool interstellar matter in early-type galaxies". Astrophysical Journal 306 (luglio 1986): 483. http://dx.doi.org/10.1086/164358.

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33

Kurchakov, A. V. "Research on diffuse nebulae and interstellar matter". Astronomical & Astrophysical Transactions 22, n. 2 (aprile 2003): 117–23. http://dx.doi.org/10.1080/1055679031000080339b.

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ZIMMERMANN, THOMAS, e JÜRGEN STUTZKI. "FRACTAL ASPECTS OF INTERSTELLAR CLOUDS". Fractals 01, n. 04 (dicembre 1993): 930–38. http://dx.doi.org/10.1142/s0218348x93000988.

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Interstellar matter consisting of gas and dust shows structures which appear to have self-similar projected shapes, similar to the properties of terrestrial clouds. Moreover, the completely different physics in these interstellar clouds reveals several additional self-similar/fractal aspects which are investigated by extensive astronomical observations, aiming especially at a better understanding of the processes of star formation which take place in interstellar molecular clouds.

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35

Dartois, Emmanuel, Ivan Alata, Cécile Engrand, Rosario Brunetto, Jean Duprat, Thomas Pino, Eric Quirico et al. "Interstellar and interplanetary solids in the laboratory". Proceedings of the International Astronomical Union 11, A29B (agosto 2015): 416–19. http://dx.doi.org/10.1017/s1743921316005688.

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AbstractThe composition of interstellar matter is driven by environmental parameters and results from extreme interstellar medium physico-chemical conditions. Astrochemists must rely on remote observations to monitor and analyze the interstellar solids composition. They bring additional information from the study of analogues produced in the laboratory, placed in simulated space environments. Planetologists and cosmochemists access and spectroscopically examine collected extraterrestrial material in the laboratory. Diffuse interstellar medium and molecular clouds observations set constraints on the composition of organic solids that can then be compared with collected extraterrestrial materials analyses, to shed light on their possible links.

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36

Pettini, M. "AAT Observations of the Interstellar Medium towards SN 1987A". Publications of the Astronomical Society of Australia 7, n. 4 (1988): 527–34. http://dx.doi.org/10.1017/s1323358000022736.

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AbstractThe exceptional brightness of SN 1987A has provided a unique opportunity to probe intervening gas clouds in the disk and halo of our Galaxy and in the Large Magellanic Cloud, as well as intergalactic matter between the two. At the AAO we have exploited this opportunity in two ways: in searches for very weak interstellar features requiring exceptionally high signal-to-noise ratio spectra, and in recording known interstellar lines with unprecedentedly high spectral resolution. We are also monitoring photographically the evolution of the light-echoes to map the three-dimensional distribution of interstellar matter near the supernova. Surprisingly high column densities of million-degree gas have been found in the LMC through the first detection of [Fe X] in absorption. The hot gas may fill the interior of a ‘superbubble’, created by the combined effects of previous supernovae in this active region of star-formation; this cavity may be related to the shells of interstellar matter giving rise to the light-echoes. The ultra-high resolution observations, which required the rapid construction of a dedicated new spectrograph, were successful in resolving the hyperfine structure of the sodium D lines in several interstellar clouds. This implies that the clouds are at temperatures of at most 170 K and have internal turbulent velocities of no more than 0.3 km s−1, even though some are moving with high velocities relative to the Sun.

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Knacke, R. F. "Comet Dust: Connections with Interstellar Dust". Symposium - International Astronomical Union 135 (1989): 415–28. http://dx.doi.org/10.1017/s0074180900125422.

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The Comet Halley campaigns resulted in an enormously better understanding of the composition of comets. Silicates, organic compounds, and volatile ices comprised of H2O, CO, CO2, S2, CN, and possibly CH4 and OCS occur in comet grains. These are all known or suspected constituents of interstellar dust. We review the chemical, elemental, and isotopic compositions of comet dust and compare this with interstellar matter. The many intriguing parallels suggest, but do not yet establish, a direct connection between comet dust and interstellar dust.

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PELTONIEMI, J. T. "SINGLET NEUTRINOS AS HOT DARK MATTER". Modern Physics Letters A 08, n. 38 (14 dicembre 1993): 3593–601. http://dx.doi.org/10.1142/s0217732393002336.

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A model is presented that generates mass and magnetic moment matrices for singlet neutrinos radiatively at one-loop level. It allows the singlet neutrinos to account for the hot dark matter and the anomalous ionization of interstellar hydrogen.

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Boulanger, François. "Dust in the Magellanic Clouds". Proceedings of the International Astronomical Union 4, S256 (luglio 2008): 137–47. http://dx.doi.org/10.1017/s1743921308028378.

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AbstractThe Magellanic Clouds are important templates for studying the role interstellar dust plays as actor and tracer of galaxy evolution. Due to their proximity, the Large and Small Magellanic clouds are uniquely suited to put detailed Galactic dust studies in a global context. With a metal abundance lower than that of the Sun, the Magellanic Clouds also permit to characterize interstellar matter composition and structure as a function of metallicity. The presentation of spectacular results from the AKARI and Spitzer surveys was one of the highlights of this Magellanic Clouds meeting. This paper puts these results in context. I discuss UV extinction and IR emission signatures of carbon and silicate dust. I present diverse evidence of dust processing in the ISM. I illustrate the correlation between the mm emission of dust, and gas column density using Milky Way surveys. I conclude with three main results. Dust in the SMC is not carbon poor. The composition of interstellar dust reflects its processing in interstellar space and thereby depends on local conditions and its past history. In the Magellanic Clouds, far-IR and sub-mm observations are indicating that there may be significantly more cold interstellar matter, cold H i and H2 gas, than estimated from H i and CO observations.

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Reynolds, R. J. "Ionized Disk/Halo Gas: Insight from Optical Emission Lines and Pulsar Dispersion Measures". Symposium - International Astronomical Union 144 (1991): 67–76. http://dx.doi.org/10.1017/s0074180900088914.

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Warm (≈ 104 K), diffuse H+ is a significant component of the interstellar medium within the Galactic disk and lower halo. This gas accounts for about one quarter of the interstellar atomic hydrogen, consumes a large fraction of the interstellar power budget, and appears to be the dominant state of interstellar matter 1 kpc above the midplane. The origin of this ionized gas is not yet established; however, of the known sources of ionization only 0 stars and perhaps supernovae produce enough power to balance the “cooling” rate of the gas. If 0 stars are the source of the ionization, then the interstellar HI, including the extended “Lockman layer”, must have a morphology that allows about 14% of the Lyman continuum photons emitted by the stars to travel hundreds of parsecs within the Galactic disk and up into the lower halo.

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Deharveng, L., A. Zavagno, L. D. Anderson, F. Motte, A. Abergel, Ph André, S. Bontemps, G. Leleu, H. Roussel e D. Russeil. "Interstellar matter and star formation in W5-E". Astronomy & Astrophysics 546 (ottobre 2012): A74. http://dx.doi.org/10.1051/0004-6361/201219131.

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42

Ehrenfreund, P., F. Robert, L. d'Hendecourt e F. Behar. "Interstellar and Meteoritic Organic Matter at 3.4 μm". Symposium - International Astronomical Union 150 (1992): 423–24. http://dx.doi.org/10.1017/s0074180900090574.

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Abstract (sommario):

The 3 micron spectrum of the galactic center source IRS 7 is compared to a spectrum obtained on the deuterium-rich organic polymer extracted from the Orgueil carbonaceous meteorite. The almost perfect match between the two spectra in the 3.4 μm region suggests that the chemical composition of the interstellar organic matter resembles that of the meteoritic macromolecule.

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43

Kim, Dong-Woo. "Interstellar matter in early-type galaxies - Optical observations". Astrophysical Journal 346 (novembre 1989): 653. http://dx.doi.org/10.1086/168048.

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44

Genzel, R. "The Circum-nuclear Disk". Symposium - International Astronomical Union 136 (1989): 393–405. http://dx.doi.org/10.1017/s0074180900186802.

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Abstract (sommario):

This review summarizes our current knowledge about the interstellar matter between about 1.7 and 10 pc(a) from IRS16/SGR A∗, a region which now commonly is referred to as the circum-nuclear disk (CND). I will discuss first the spatial distribution of the neutral and partially ionized, interstellar matter, then its physical parameters and excitation and, finally its dynamics. For other recent reviews of the subject I refer to the articles by Güsten (1987), Genzel (1987), Genzel and Townes (1987) and Jaffe (1987).

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45

Chekulaev M. S. e Yastrebov S. G. "Spectrum of a hybrid C-=SUB=-73-=/SUB=-H-=SUB=-90-=/SUB=- molecule containing the Stone-Wallace defect". Technical Physics Letters 48, n. 15 (2022): 71. http://dx.doi.org/10.21883/tpl.2022.15.54272.18951.

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The spectral characteristics of hybtid cluster C73H90 were calculated using the time-dependent Density Functional Theory method. The calculated spectrum demonstrates two maxima: at 5.7 and 3.8 eV, which are close to those in interstellar medium and laboretory experiments. Keywords: interaction of light with matter, new forms of carbon, interstellar medium, Stone-Wales defect.

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46

L. Frantsman, Ju. "Radioactive Isotope 26Al in the Interstellar Matter (Resulting From a Mass Loss by AGB Stars)". Symposium - International Astronomical Union 150 (1992): 411–12. http://dx.doi.org/10.1017/s0074180900090537.

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Abstract (sommario):

Several calculations of the Asymptotic Giant Branch star evolution have been performed with the aim of explaining the synthesis of interstellar 26Al in these stars. The agreement of theoretically calculated mass of interstellar 26Al and observations is rather satisfactory, the best for the abrupt tenfold jump in the mass-loss rate for the stars reaching the luminosity log(L/L⊙) ⋍ 4.0.

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47

Holmlid, Leif. "Nuclear Processes in Dark Interstellar Matter of H(0) Decrease the Hope of Migrating to Exoplanets". Space: Science & Technology 2021 (3 settembre 2021): 1–6. http://dx.doi.org/10.34133/2021/9846852.

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Abstract (sommario):

It is still generally assumed that interstellar travel will be possible after purely technical development and thus that mankind can move to some suitable exoplanet when needed. However, recent research indicates this not to be the case, since interstellar space is filled with enough ultradense hydrogen H(0) as stable condensed dark matter (Holmlid, Astrophysical Journal 2018) to make interstellar space travel at the required and technically feasible relativistic velocities (Holmlid et al, Acta Astronautica 2020) almost impossible. H(0) can be observed to exist in space from the so-called extended red emission (ERE) features observed in space. A recent review (Holmlid et al., Physica Scripta 2019) describes the properties of H(0). H(0) gives nuclear processes emitting kaons and other particles, with kinetic energies even above 100 MeV after induction for example by fast particle (spaceship) impact. These high particle energies give radiative temperatures of 12000 K in collisions against a solid surface and will rapidly destroy any spaceship structure moving into the H(0) clouds at relativistic velocity. The importance of preserving our ecosystem is pointed out, since travel to suitable exoplanets may be impossible. The possibilities of instead clearing interstellar space from H(0) are discussed, eventually providing tunnels suitable for relativistic interstellar transport. Finding regions with low intensity of ERE could even be a way to identify space-cleaning activities and thus to locate earlier space-travelling civilizations.

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48

Krełowski, Jacek. "Diffuse Interstellar Bands – The Unidentified Part of the Interstellar Absorption Spectrum". Symposium - International Astronomical Union 135 (1989): 67–86. http://dx.doi.org/10.1017/s0074180900125112.

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The unidentified (since 1921) diffuse interstellar bands (DIBs) are discussed together with their relations to other interstellar absorptions sucn as: continuous extinction, polarization and atomic or molecular absorption lines. It is shown that DIBs do not form the absorption spectrum of one agent, but probably of several (3 or more). DIBs as well as other interstellar absorptions are usually formed in several clouds along a line-of-sight. Thus, they suffer Doppler splitting; the first high resolution profiles free of the latter effect are described. Since single interstellar clouds may differ not only in radial velocities but also in many physical (optical) parameters, the observed interstellar absorptions are ill-defined averages over all clouds situated along any line-of-sight. It is of basic importance to determine not only the single cloud profiles of diffuse bands, but also their relations to other interstellar absorptions in the same clouds. Intensity ratios of DIBs are shown to be sensitive to the shapes of extinction curves, depletion patterns of elements and molecular abundances in the considered clouds. The sensitivity of the DIBs to the variation in polarization is less documented but probably also present. Thus the diffuse lines are presented as the unidentified part of the absorption spectrum of interstellar matter. Their identification depends on the determination of their relations to other interstellar absorptions which must be determined precisely.

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49

Busemann, Henner, Conel M. O'D Alexander, Larry R. Nittler, Rhonda M. Stroud, Tom J. Zega, George D. Cody, Hikaru Yabuta e A. L. David Kilcoyne. "Structural, chemical and isotopic examinations of interstellar organic matter extracted from meteorites and interstellar dust particles". Proceedings of the International Astronomical Union 4, S251 (febbraio 2008): 333–34. http://dx.doi.org/10.1017/s1743921308021881.

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Abstract (sommario):

AbstractMeteorites and Interplanetary Dust Particles (IDPs) are supposed to originate from asteroids and comets, sampling the most primitive bodies in the Solar System. They contain abundant carbonaceous material. Some of this, mostly insoluble organic matter (IOM), likely originated in the protosolar molecular cloud, based on spectral properties and H and N isotope characteristics. Together with cometary material returned with the Stardust mission, these samples provide a benchmark for models aiming to understand organic chemistry in the interstellar medium, as well as for mechanisms that secured the survival of these fragile molecules during Solar System formation. The carrier molecules of the isotope anomalies are largely unknown, although amorphous carbonaceous spheres, so-called nanoglobules, have been identified as carriers. We are using Secondary Ion Mass Spectrometry to identify isotopically anomalous material in meteoritic IOM and IDPs at a ~100-200 nm scale. Organics of most likely interstellar origin are then extracted with the Focused-Ion-Beam technique and prepared for synchrotron X-ray and Transmission Electron Microscopy. These experiments yield information on the character of the H- and N-bearing interstellar molecules: While the association of H and N isotope anomalies with nanoglobules could be confirmed, we have also identified amorphous, micron-sized monolithic grains. D-enrichments in meteoritic IOM appear not to be systematically associated with any specific functional groups, whereas 15N-rich material can be related to imine and nitrile functionality. The large 15N- enrichments observed here (δ15N > 1000 ‰) cannot be reconciled with models using interstellar ammonia ice reactions, and hence, provide new constraints for understanding the chemistry in cold interstellar clouds.

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50

Flynn, G. J., L. P. Keller, S. Wirick e C. Jacobsen. "Organic matter in interplanetary dust particles". Proceedings of the International Astronomical Union 4, S251 (febbraio 2008): 267–76. http://dx.doi.org/10.1017/s174392130802173x.

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Abstract (sommario):

AbstractAnhydrous interplanetary dust particles (IDPs), which are the most mineralogically primitive extraterrestrial materials available for laboratory analysis, contain several percent organic matter. The high O:C and N:C ratios suggest the organic matter in the anhydrous IDPs is significantly less altered by thermal processing than the organic matter in meteorites. X-ray Absorption Near-Edge Structure (XANES) spectroscopy and infrared spectroscopy demonstrate the presence of C=C, most likely as C-rings, C=O, and aliphatic C-H2and C-H3in all the IDPs examined. A D-rich spot, containing material that is believed to have formed in a cold molecular cloud, has C-XANES and infrared spectra very similar to the organic matter in the anhydrous IDPs, possibly indicating a common formation mechanism. However the primitive organic matter in the IDPs differs from the interstellar/circumstellar organic matter characterized by astronomical infrared spectroscopy in the relative strengths of the asymmetric aliphatic C-H2and C-H3absorptions, with the IDP organic having a longer mean chain length. If both types of organic matter originated by the same process, this may indicate the interstellar organic matter has experienced more severe radiation processing than the organic matter in the primitive IDPs.

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