Дисертації з теми "Intersteller hydrogen"
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Malawi, Abdulrahman Ali. "Atomic hydrogen associated with high latitude IRAS cirrus clouds." Thesis, University of Manchester, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664465.
Повний текст джерелаIslam, F. "The formation of molecular hydrogen in the interstellar medium." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/19475/.
Повний текст джерелаIrving, Benjamin James. "The formation of molecular hydrogen in the interstellar medium." Thesis, University of Sheffield, 2012. http://etheses.whiterose.ac.uk/3104/.
Повний текст джерелаKreckel, Holger. "Internal excitations of stored triatomic hydrogen molecular ions." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968519563.
Повний текст джерелаBurton, Michael Graham. "The shock-excitation of molecular hydrogen in the interstellar medium." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/855.
Повний текст джерелаWard, M. D. "Reactions of hydrogen and oxygen atoms on interstellar grain analogues." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1355953/.
Повний текст джерелаRichter, Philipp. "FUV absorption spectroscopy of interstellar molecular hydrogen towards the Magellanic clouds /." Aachen : Shaker, 1999. http://catalogue.bnf.fr/ark:/12148/cb37739235j.
Повний текст джерелаFUV = far ultraviolet. Bibliogr. p. 83-85.
Gaylard, Michael John. "Radio studies of ionized hydrogen in the southern Milky Way." Thesis, Rhodes University, 1990. http://hdl.handle.net/10962/d1001993.
Повний текст джерелаGavilan, Lisseth. "The formation of molecular hydrogen on interstellar silicatesé : from experiments to observations." Observatoire de Paris, 2013. https://hal.science/tel-02095146.
Повний текст джерелаThe goal of this thesis is to understand the formation of molecular hydrogen in the interstellar medium (ISM) via laboratory experiments and astronomical observations. The experiments are performed with FORMOLISM, an ultra-high vacuum setup to study the formation of molecules in the ISM. We are interested in the energy disposal during the exhothermic recombination of two H atoms on a cryogenically cooled surface (< 10 K). Resonance Enhanced Multi-Photon Ionization ( REMPI 2 + 1) spectroscopy is used to probe the population of rovibrational levels in the ground electronic state of molecular hydrogen after formation. We have tested different surfaces of astrophysical relevance : amorphous and crystalline silicates, porous amorphous solid water, and a bare silicate pre-dosed with hydrogen molecules. We have confirmed the formation enhancement of molecular hydrogen on a surface pre-dosed with molecules and quantified D₂formation as a non-thermal desorption mechanism. We have also measured the ortho-to-para ratio of newly formed molecular hydrogen on p-ASW, finding that it corresponds to the value expected at statistical equilibrium at high temperature. Silicate analog surfaces (forsterite and fayalite) have been fabricated to test the influence of their morphology and chemical composition on hydrogen formation. We have found that newly formed molecular hydrogen leaves rotationally cooler (with respect to the molecular beam rotational temperature) from crystalline surfaces, and that it is unaffected when it scatters from amorphous surfaces. We have also detected nuclear spin conversion of molecular hydrogen absorbed on bare silicates. Observational predictions from these experiments are tested using long slit near infrared spectroscopy available at the VLT and Keck telescopes. Planetary nebulae with H₂ and X-ray emission were chosen as ideal targets. H₂transitions have been detected throughout our targets. The intensity distribution of these transitions will be compared to models of formation pumping spectra. In addition, part of this thesis addresses the VUV high-resolution spectroscopy of CO and its isotopologues, using the Fourier Transform Spectrometer at the SOLEIL synchroton. This complements the work on hydrogen in the wider context of the astrochemistry of small molecules
Kulesa, Craig A. "Molecular hydrogen and its ions in dark interstellar clouds and star forming regions." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/280192.
Повний текст джерелаMatar, Elie. "Interaction of atomic and molecular hydrogen on amorphous water ice surfaces mimicking interstellar dust." Cergy-Pontoise, 2009. http://biblioweb.u-cergy.fr/theses/09CERG0431.pdf.
Повний текст джерелаAmong the different structures of the universe exists what we call the interstellar medium (ISM). It is a place where gas and dust coexist and interact in perfect harmony. In this medium, molecular hydrogen is the most abundant gaseous species and by far the most important one. It is the principal constituent of three of four molecules essential to the existence of life: water, methane, amine and carbon monoxide. The physico-chemistry of the ISM that leads to the formation of new molecules is divided in two: the gas-phase reactions and the gas-dust reactions. The second one being the most efficient route of molecular hydrogen in space. This thesis work is an experimental contribution to study the interaction and the formation of molecular hydrogen on the surface of amorphous water ice surfaces covering dust grains in dark clouds. For this, by uniting ultra-high vacuum techniques, cryogenic systems, atomic and molecular beams, mass spectroscopy and modelling, several experiments have been conducted by using the FOMOLISM experimental set-up (FORmation of MOLecules in the InterStellar Medium)
Wong, Oiwei Ivy. "Star formation and galaxy evolution of the local universe based on HIPASS /." Connect to thesis, 2007. http://eprints.unimelb.edu.au/archive/00004069.
Повний текст джерелаBagetakos, Ioannis. "Shells, bubbles and holes : the porosity of the interstellar medium in galaxies." Thesis, University of Hertfordshire, 2012. http://hdl.handle.net/2299/9085.
Повний текст джерелаHunt, Maria, University of Western Sydney, of Science Technology and Environment College, and School of Engineering and Industrial Design. "Molecules in southern molecular clouds: a millimetre-wave study of dense cores." THESIS_CSTE_EID_Hunt_M.xml, 2001. http://handle.uws.edu.au:8081/1959.7/116.
Повний текст джерелаDoctor of Philosophy (PhD)
Navarro, Ruiz Javier. "Theoretical investigations of H2 Formation on interstellar silicates surfaces." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/377749.
Повний текст джерелаAmong the molecules in space, H2 is one of the most relevant of the universe. It is the most abundant one in the interstellar medium and is a key intermediate for the formation of bigger molecules. Its formation is complex, but due to its inherent relevance understanding its interaction and its formation can be considered as a paradigm of the astrophysical process. The present thesis introduces in Chapter 1 the astrochemical framework in which the thesis is located, pointing out the presence of interstellar hydrogen in the interstellar medium and where it takes place, in the interstellar dust grains around. After presenting the goals this thesis aims, Chapter 2 overviews the general theoretical aspects behind it, such as electronic structure, density functional methods, solids modelling and tunnelling effects, providing finally the computational details entailed. Chapter 3 corresponds to results and discussion and is divided into different sections. Section 3.1 presents some physicochemical properties of the crystalline bulk structure and the corresponding surfaces of Mg2SiO4 forsterite and of the Fe-containing Mg1.5Fe0.5SiO4 olivine systems. Section 3.2 reports the adsorption of H atoms and their recombination to form a H2 molecule on the crystalline Mg2SiO4 forsterite (010) surface and Section 3.3 analyses the relevance of surface morphology by considering the H2 formation on the crystalline Mg2SiO4 forsterite (001) and (110) surfaces. Finally, Section 3.4 investigates the influence of Fe2+ atoms by modelling the physisorption/chemisorption of H atom on the Fe-containing (010) surface, subsequently taking place the formation of H2. Chapter 4 addresses the general conclusions of the present thesis and possible future perspectives, Chapter 5 includes the references cited and Appendix A and B supports the information given in Chapter 3.
Wang, Xiang. "PROBING PHYSICAL CONDITIONS IN THE CRAB NEBULA WITH EMISSION LINE ANALYSIS." UKnowledge, 2016. http://uknowledge.uky.edu/physastron_etds/36.
Повний текст джерелаValdivia, Valeska. "Impact of radiative transfer and chemistry on the formation of molecular clouds." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066709/document.
Повний текст джерелаThe interstellar medium (ISM) is a highly complex system. It corresponds to an intermediate scale between stars and galaxies. The interstellar gas is present throughout the galaxy, filling the volume between stars. A wide variety of coupled processes, such as gravity, magnetic fields, turbulence and chemistry, participate in its evolution, making the modeling of the ISM a challenging problem. A correct description of the ISM requires a good treatment of the magnetohydrodynamics (MHD) equations, gravity, thermal balance, and chemical evolution within the molecular clouds.This thesis work aims at a better understanding of the formation and evolution of molecular clouds, specially how they become "molecular", paying particular attention to the transition HI-to-H2. We have performed ideal MHD simulations of the formation of molecular clouds and the formation of molecular hydrogen under the influence of gravity and turbulence, using accurate estimates for the shielding effects from dust and the self-shielding for H2, calculated with a Tree-based method, able to provide fast estimates of column densities.We find that H2 is formed faster than predicted by the usual estimates due to local density enhancements created by the gas turbulent motions. Molecular hydrogen, formed at higher densities, could then migrate toward low density warmer regions.Total H2 column densities show that the HI-to-H2 transition occurs at total column densities of a few 10^20 cm−2. We have calculated the populations of rotational levels of H2 at thermal equilibrium, and integrated along several lines of sight. These two results reproduce quite well the values observed by Copernicus and FUSE, suggesting that the observed transition and the excited populations could arise as a consequence of the multi-phase structure of molecular clouds. As H2 formation is prior to further molecule formation, warm H2 could possibly allow the development of a warm chemistry, and eventually explain some aspects of the molecular richness observed in the ISM
Pawson, Trevor G. "Harmonic vibrational effects on isotropic hyperfine coupling constants molecular hydrogen in interstellar ice and atomic relaxation in doped silicon." Thesis, University of Leicester, 1998. http://hdl.handle.net/2381/30015.
Повний текст джерелаSaury, Eléonore. "Turbulence et instabilité thermique du milieu interstellaire atomique neutre : une approche numérique." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00784196.
Повний текст джерелаBorodi, Gheorghe. "On the combination of a low energy hydrogen atom beam with a cold multipole ion trap." Doctoral thesis, Universitätsbibliothek Chemnitz, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200900932.
Повний текст джерелаThe first part of the activities of this thesis was to develop a sophisticated ion storage apparatus dedicated to study chemical processes with atomic hydrogen. The integration of a differentially pumped radical beam source into an existing temperature variable 22-pole trapping machine has required major modifications. Since astrophysical questions have been in the center of our interest, the introduction first gives a short overview of astrophysics and -chemistry. The basics of ion trapping in temperature variable rf traps is well-documented in the literature; therefore, the description of the basic instrument (Chapter 2) is kept rather short. Much effort has been put into the development of an intense and stable source for hydrogen atoms the kinetic energy of which can be changed. Chapter 3 describes this module in detail with emphasis on the integration of magnetic hexapoles for guiding the atoms and special treatments of the surfaces for reducing H-H recombination. Due to the unique sensitivity of the rf ion trapping technique, this instrument allows one to study a variety of reactions of astrochemical and fundamental interest. The results of this work are summarized in Chapter 4, some reprints and drafts are reproduced in the appendix. Reactions of CO2+ with hydrogen atoms and molecules have been established as calibration standard for in situ determination of H and H2 densities over the full temperature range of the apparatus (10 K - 300 K). For the first time, reactions of H- and D-atoms with the ionic hydrocarbons CH+, CH2+, and CH4+ have been studied at temperatures of interstellar space. A very interesting, not yet fully understood collision system is the interaction of protonated methane with H. The outlook presents some ideas, how to improve the new instrument and a few reaction systems are mentioned which may be studied next. This thesis is a contribution to the project 5 of the research unit Laboratory Astrophysics: Structure, Dynamics and Properties of Molecules and Grains in Space which has been supported by the DFG from 2000 to 2006
Ratajczak, Alexandre. "Echanges hydrogène/deutérium dans les glaces interstellaires : une origine de la deutération sélective." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00767169.
Повний текст джерелаReynaud, Denis. "Dynamique du gaz interstellaire dans les galaxies spirales barrées : une étude en interférométrie millimétrique de NGC 1530." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10044.
Повний текст джерелаLin, Zhou. "Theoretical Studies on the Spectroscopy and Dynamics of Astrochemically Significant Species." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429633299.
Повний текст джерелаJacq, Thierry. "Le survey radiomillimetrique de l'observatoire de bordeaux : le gaz moleculaire interstellaire dans le plan galactique entre l=38 et l=67.5, structure spirale, nuages moleculaires, comparaison entre hi et **(13)co. ch dans le nuage sombre lynds 134." Paris 6, 1987. http://www.theses.fr/1987PA066440.
Повний текст джерелаGodard, Marie. "Les carbones amorphes hydrogénés : observations, synthèse et caractérisation en laboratoire de poussières interstellaires." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00635907.
Повний текст джерелаPutman, Mary Elaine. "Mapping the galaxy's neutral hydrogen halo." Phd thesis, 2000. http://hdl.handle.net/1885/147934.
Повний текст джерелаKim, Sungeun. "An HI aperture synthesis mosaic and H[alpha] survey of the Large Magellanic Cloud." Phd thesis, 1998. http://hdl.handle.net/1885/144477.
Повний текст джерелаCazaux, Stéphanie Michelle. "Grain surface chemistry in astrophysical objects : from H₂ to complex molecules /." 2004. http://dissertations.ub.rug.nl/faculties/science/2004/s.m.cazaux/.
Повний текст джерелаDePoy, Darren Lee. "The nature of luminous IRAS galaxies." Thesis, 1987. http://hdl.handle.net/10125/9343.
Повний текст джерелаEnglish, Jayanne. "Gas dynamics and globular cluster formation in interacting galaxies." Phd thesis, 1994. http://hdl.handle.net/1885/138288.
Повний текст джерелаKornbleuth, Marc Zachary. "Using hydrogen energetic neutral atoms to study the heliosphere." Thesis, 2020. https://hdl.handle.net/2144/42001.
Повний текст джерелаLah, Philip. "The evolution of gas in galaxies." Phd thesis, 2009. http://hdl.handle.net/1885/151694.
Повний текст джерелаEtim, Emmanuel Edet. "Computational Studies on Interstellar Molecular Species : From Formation to Detection." Thesis, 2016. http://hdl.handle.net/2005/3216.
Повний текст джерелаSicking, Floris Jan. "The thickness of the HI gas layer in spiral galaxies." 1997. http://catalog.hathitrust.org/api/volumes/oclc/37547343.html.
Повний текст джерелаMichael, Adam Thomas. "The influence of the solar magnetic field on the heliosphere, with a kinetic description of neutral hydrogen." Thesis, 2019. https://hdl.handle.net/2144/38401.
Повний текст джерелаBorodi, Gheorghe. "On the combination of a low energy hydrogen atom beam with a cold multipole ion trap." Doctoral thesis, 2008. https://monarch.qucosa.de/id/qucosa%3A19141.
Повний текст джерелаThe first part of the activities of this thesis was to develop a sophisticated ion storage apparatus dedicated to study chemical processes with atomic hydrogen. The integration of a differentially pumped radical beam source into an existing temperature variable 22-pole trapping machine has required major modifications. Since astrophysical questions have been in the center of our interest, the introduction first gives a short overview of astrophysics and -chemistry. The basics of ion trapping in temperature variable rf traps is well-documented in the literature; therefore, the description of the basic instrument (Chapter 2) is kept rather short. Much effort has been put into the development of an intense and stable source for hydrogen atoms the kinetic energy of which can be changed. Chapter 3 describes this module in detail with emphasis on the integration of magnetic hexapoles for guiding the atoms and special treatments of the surfaces for reducing H-H recombination. Due to the unique sensitivity of the rf ion trapping technique, this instrument allows one to study a variety of reactions of astrochemical and fundamental interest. The results of this work are summarized in Chapter 4, some reprints and drafts are reproduced in the appendix. Reactions of CO2+ with hydrogen atoms and molecules have been established as calibration standard for in situ determination of H and H2 densities over the full temperature range of the apparatus (10 K - 300 K). For the first time, reactions of H- and D-atoms with the ionic hydrocarbons CH+, CH2+, and CH4+ have been studied at temperatures of interstellar space. A very interesting, not yet fully understood collision system is the interaction of protonated methane with H. The outlook presents some ideas, how to improve the new instrument and a few reaction systems are mentioned which may be studied next. This thesis is a contribution to the project 5 of the research unit Laboratory Astrophysics: Structure, Dynamics and Properties of Molecules and Grains in Space which has been supported by the DFG from 2000 to 2006.
Roy, Arpita. "A Study of Superbubbles in the ISM : Break-Out, Escape of LYC Photons and Molecule Formation." Thesis, 2016. http://hdl.handle.net/2005/3120.
Повний текст джерела