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1

Beletsky, Yuri. "Extragalactic molecular clouds and chemistry of diffuse interstellar clouds." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-105670.

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2

Vichetti, Rafael Mário [UNESP]. "Síntese dos isótopos do monóxido de carbono no meio interestelar." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/91889.

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Made available in DSpace on 2014-06-11T19:25:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-21Bitstream added on 2014-06-13T19:53:20Z : No. of bitstreams: 1 vichietti_rm_me_rcla.pdf: 842604 bytes, checksum: 731ca276a75c1b92840e57bd7497b5e1 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>De acordo com os resultados observacionais de condensações de nuvens moleculares escuras, grandes variações na razão 13CO/C18O são observadas quando se comparam os resultados obtidos nas condensações situadas dentro da mesma nuvem, bem como de nuvem para nuvem. O
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3

Brown, Ian David. "The velocity of molecular clouds." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293612.

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4

Bretherton, Derek. "Star formation in molecular clouds." Thesis, Liverpool John Moores University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402927.

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5

Rowles, Jonathan Henry. "The structure of molecular clouds." Thesis, University of Kent, 2011. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.544095.

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6

Richardson, Kevin John. "Submillimetre molecular line observations and modelling of molecular clouds." Thesis, Queen Mary, University of London, 1985. http://qmro.qmul.ac.uk/xmlui/handle/123456789/1705.

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Submillimetre molecular line observations of molecular clouds in our galaxy are presented, and the data analysed using various alternative cloud models. A critical review is given of the methods commonly used to interpret molecular line data, including both theoretical considerations and issues relating to calibration and comparability of results obtained with different telescopes. A detailed comparison is made between results predicted from large velocity gradient (LVG) models, including the generalisation to non-monotonic velocity flows, and those given by "microturbulent" clouds. An LVG mod
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7

McElroy, Daniel. "Grain surface chemistry in molecular clouds." Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602462.

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This work ia a study of chemistry in molecular clouds. I begin by describing the improvements made to gas phase chemical reaction data in the recent release of the UMIST database for astrochemistry (Rate 12). Improvements to the reaction network include the addition of anions, new reaction rate coefficient and branching rate measurements across all reactions types and newly calculated photodissociation and photoionisation rates.
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8

Morisawa, Yusuke. "Spectroscopic study of some chemically significant molecules in molecular clouds." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144599.

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9

García, Fuentes Pablo Fernando. "Giant Molecular Clouds in the Southern Milky Way." Tesis, Universidad de Chile, 2007. http://www.repositorio.uchile.cl/handle/2250/104575.

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10

Dobbs, Clare Louise. "The formation of molecular clouds in spiral galaxies /." St Andrews, 2007. http://hdl.handle.net/10023/214.

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11

Fiege, Jason D. "Filamentary molecular clouds and their prolate cores." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0032/NQ66208.pdf.

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12

Hobson, Michael Paul. "The small-scale structure of molecular clouds." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282113.

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13

Visser, Anja Eveline. "Star forming cores in dark molecular clouds." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620970.

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14

Penaloza, Cabrera Camilo. "Giant molecular clouds : a view through molecular tracers and synthetic images." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/116132/.

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Line emission is strongly dependent on the local environmental conditions in which the emitting tracers reside. In this work, we focus on modelling the CO emission from simulated giant molecular clouds (GMCs), and study the variations in the resulting line ratios arising from the emission from the J = 1 − 0, J = 2 − 1 and J = 3 − 2 transitions. We first study the ratio (R2−1/1−0) between CO’s first two emission lines and examine what information it provides about the physical properties of the cloud. To study R2−1/1−0 we perform smooth particle hydrodynamic simulations with time dependent chem
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15

Hunt, 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.

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This thesis presents an observational study of molecular abundances in the dense cores of 27 prominent molecular clouds in the southern galactic plane.The molecular abundances and physical conditions in dense condensations have been derived from millimetre-wavelength observations of molecular rotational transitions.The study has produced a comprehensive data set of transition intensities and abundances for 10 different molecules in bright southern molecular clouds, and the general characteristics of emissions from these molecules such as optical depth, excitation and relative abundances are di
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16

Hunt, Maria. "Molecules in southern molecular clouds: a millimetre-wave study of dense cores." Thesis, View thesis View thesis, 2001. http://handle.uws.edu.au:8081/1959.7/116.

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This thesis presents an observational study of molecular abundances in the dense cores of 27 prominent molecular clouds in the southern galactic plane.The molecular abundances and physical conditions in dense condensations have been derived from millimetre-wavelength observations of molecular rotational transitions.The study has produced a comprehensive data set of transition intensities and abundances for 10 different molecules in bright southern molecular clouds, and the general characteristics of emissions from these molecules such as optical depth, excitation and relative abundances are di
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17

Hunt, Maria. "Molecules in southern molecular clouds : a millimetre-wave study of dense cores /." View thesis View thesis, 2001. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030416.160909/index.html.

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18

Dobbs, Clare L. "The formation of molecular clouds in spiral galaxies." Thesis, University of St Andrews, 2007. http://hdl.handle.net/10023/214.

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Molecular clouds are imperative to astronomy as the sites of all known star formation. The problem of how molecular clouds are formed in spiral galaxies is approached numerically, by modelling the response of a gas disk to a spiral potential. The importance of spiral shocks is highlighted as a dominant formation mechanism for molecular clouds in grand design galaxies, where a strong density wave is present. The spiral shock both increases the density of the interstellar gas significantly, and produces structure in the spiral arms. The gas evolves into discrete clumps, which are shown to contai
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19

Olofsson, Sven. "Extinction in Molecular Clouds : Case of Barnard 335." Doctoral thesis, Stockholms universitet, Institutionen för astronomi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-72523.

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The Bok globule B335 is a small molecular cloud in the solar neighbourhood near the galactic plane. The aim for this three-paper-study is to construct and analyze the extinction for this globule. The method we apply is to use the light from field stars behind the cloud in broadband filters ranging from UV to the mid-infrared. We have observations performed at the ESO telescopes at La Silla and Paranal as well as at the Nordic 2.5 m telescope at La Palma. Together with images and spectra from 2MASS-, ISO- and Spitzer-archives we are able to cover the wavelength range from 0.35 to 24 μm. An impo
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20

Clark, Paul Campbell. "The onset of gravitational collapse in molecular clouds." Thesis, University of St Andrews, 2005. http://hdl.handle.net/10023/12945.

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We conduct an investigation into the role that turbulence plays in the formation of stars. In small clouds, with masses of ~ 30 Mʘ and where the turbulence is only injected at the start, we find that the turbulence does not trigger star formation. Instead, the dissipation of the kinetic energy allows the mean Jeans mass of the cloud to control the formation of stars. The equipartition of the kinetic and thermal energies in the final stages before star formation, allows the pre-protostellar clumps to fragment. Binary and multiple systems are thus a natural product of star formation in a turbule
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21

McLaughlin, Dean E. "Star formation in molecular clouds and globular clusters." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ30104.pdf.

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22

Parker, Nicholas David. "Studies of star formation in dark molecular clouds." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315051.

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23

Anathpindika, Sumedh V. "Smoothed particle hydrodynamics simulations of colliding molecular clouds." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54779/.

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The galactic disk is largely composed of hot, rarefied gas also called the inter cloud medium (ICM). The cooler regions of the ICM are dominated by molecular species and dust. Immersed in this neutral medium are dense agglomerations of primarily H2, called giant molecular clouds (GMCs). The GMCs have a velocity dispersion of order a few km s_1, superimposed on their orbital motion. A GMC, over a single period of rotation of the galaxy, may undergo a few tens of collisions. In the present work, we investigate this rather violent phenomenon and examine the prospects of star formation in the post
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24

Aguti, Esther D. "A study of dense and translucent molecular clouds." Thesis, University of Bristol, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441649.

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25

Richardson, K. M. "Gamma rays, cosmic rays and local molecular clouds." Thesis, Durham University, 1988. http://etheses.dur.ac.uk/942/.

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26

Karlsson, Roland. "Studies of molecular clouds at the Galactic centre." Doctoral thesis, Stockholms universitet, Institutionen för astronomi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-126752.

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Interstellar molecular clouds play an essential role in the Universe. Such clouds are invoked for the production and destruction of stars, galaxies and gas and also for energy transport in galaxies. The Galaxy, or the Milky Way, is a large spiral galaxy, with a central bar structure, that harbours a few hundred billion stars and large amounts of gas and dust. At the centre of the Galaxy, a 4 million solar mass supermassive black hole resides, surrounded by a dense core of millions of stars, as well as molecular and dust clouds. The Galactic centre (GC) is hidden by gas and dust, such that only
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27

Lee, Ho-Hsin. "Gas-phase chemical models of interstellar molecular clouds /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487948440824473.

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28

Rice, Johnathan Scott. "The Transition From Diffuse to Dense Molecular Clouds." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1534945134382193.

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29

Gritschneder, Matthias. "Ionization and Triggered Star Formation in Turbulent Molecular Clouds." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-104903.

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30

Gong, Hao. "Dense core formation and collapse in giant molecular clouds." Thesis, University of Maryland, College Park, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3587424.

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<p> In this thesis we present a unified model for dense core formation and collapse within post-shock dense layers inside giant molecular clouds. Supersonic converging flows collide to compress low density gas to high density clumps, inside which gravitational collapse can happen. We consider both spherically symmetric and planar converging flows, and run models with inflow Mach number from 1.1-9 to investigate the relation between core properties and the bulk velocity dispersion of the mother cloud. Four stages of protostar formation are identified: core building, core collapse, envelope
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31

Bell, G. S. "HARP-B and wide-field imaging of molecular clouds." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596542.

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Part I of this thesis describe HARP-B – a new heterodyne array receiver operating at 345 GHz on the James Clerk Maxwell Telescope. The work described focuses on the optics, interferometer and commissioning of HARP-B. Careful testing and alignment of the optics was necessary to ensure that HARP-B would perform as required. Its Mach-Zehnder interferometer was put under computer control and characterised to allow it to be used as an effective sideband filter. This part concludes with the integration and commissioning of the receiver, leading up to first light. Part II then presents wide-field obs
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32

Rigby, A. J. "Molecular clouds and star formation in the Inner Galaxy." Thesis, Liverpool John Moores University, 2016. http://researchonline.ljmu.ac.uk/4172/.

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A detailed understanding of the process of star formation is crucial for modern astrophysics. Stars form from the gravitational collapse of molecular gas clouds; it is the process by which cold molecular gas is transformed into the stars and planets that make up the many billions of galaxies in the observable Universe. However, there are a number of open questions that have yet to be answered and a comprehensive theory that explains and predicts how, where and why stars and their clusters form proves elusive. One such open question is how does the environment, on both local scales and galactic
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33

van, Dishoeck E. F. "Interstellar C2, CH, and CN in Translucent Molecular Clouds." Steward Observatory, The University of Arizona (Tucson, Arizona), 1988. http://hdl.handle.net/10150/623918.

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Optical absorption line techniques have been applied to the study of a number of translucent molecular clouds in which the total column densities are large enough that substantial molecular abundances can be maintained. Results are presented for a survey of absorption lines of interstellar C2, CH, and CN. Detections of CN through the A2II -X2E+ (1,0) and (2,0) bands of the red system are reported, and are compared with observations of the blue system for one line of sight. The population distributions in C2 provide diagnostic information on temperature and density. The measured column de
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34

Chapman, Nicholas. "Dust structure and composition within molecular clouds and cores." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7613.

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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.<br>Thesis research directed by: Dept. of Astronomy. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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35

Yan, Qingzeng. "Molecular clouds and star formation in the Milky Way." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/75787.

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Using molecular line observations, this thesis studied the molecular clouds of three typical regions of the Milky Way, which are the Galactic centre, high Galactic latitudes, and the Galactic plane. The properties of molecular clouds show remarkable variations among these three regions, which explains why the star formation activities are so different.
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36

Murphy, Brian Timothy. "Isotopomeric carbon compounds in star formation regions." Thesis, University of Kent, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270812.

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37

Park, In Hee. "Dark cloud modeling for the ortho-to-para abundance ratio of the cyclic C3H2." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117125089.

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Thesis (M.S.)--Ohio State University, 2005.<br>Title from first page of PDF file. Document formatted into pages; contains xiii, 107 p.; also includes graphics Includes bibliographical references (p. 103-107). Available online via OhioLINK's ETD Center
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38

Vichetti, Rafael Mário. "Síntese dos isótopos do monóxido de carbono no meio interestelar /." Rio Claro : [s.n.], 2009. http://hdl.handle.net/11449/91889.

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Orientador: Carmen Maria Andreazza<br>Banca: Edson Denis Leonel<br>Banca: José Williams dos Santos Vilas Boas<br>Resumo: De acordo com os resultados observacionais de condensações de nuvens moleculares escuras, grandes variações na razão 13CO/C18O são observadas quando se comparam os resultados obtidos nas condensações situadas dentro da mesma nuvem, bem como de nuvem para nuvem. O valor médio dessa razão na condensação principal de Ophiuchus é inferior a 5. Por outro lado, o valor encontrado nas condensações que estão situadas ao norte de Oph é maior que 10. Grandes diferenças também são enco
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39

Finn, Susanna C. "Molecular line observations of Infrared Dark Clouds in the Galaxy." Thesis, Boston University, 2012. https://hdl.handle.net/2144/32014.

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Thesis (Ph.D.)--Boston University<br>PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.<br>Although massive stars play many important roles in the universe, their formation is poorly understood. Recently, a class of interstellar clouds known as Infrared Dark Clouds (IRDCs) has been identified as li
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40

Greene, T. P., and E. T. Young. "IRAS Observations of Dust Heating and Energy Balance in the FHO Ophiuchi Dark Cloud." Steward Observatory, The University of Arizona (Tucson, Arizona), 1989. http://hdl.handle.net/10150/623887.

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The total luminosity of the Rho Ophiuchi molecular cloud is derived from IRAS data and is found to match the luminosity of known embedded sources very closely. High resolution 60 and 100 micron band IRAS images have been reduced to yield equilibrium color temperature maps and 60 micron band dust optical depth maps for the region. These data along with optically thin C18O column density data are used to evaluate dust grain sizes and compositions via competing grain models. Radiative modeling shows that a standard power law distribution of graphite and silicate grains is responsible for I
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41

Matthews, Brenda Christine. "A polarimetric study of magnetic fields in star-forming molecular clouds /." *McMaster only, 2001.

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42

Walker, Christopher Kidd. "An observational study of the dynamics of molecular cloud cores." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184585.

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How are stars formed? This is one of the most fundamental questions in astronomy. It is therefore ironic that to date, no object has been unambiguously identified as a true protostar; an object which derives the bulk of its luminosity from accretion. While this may be ironic, it is not surprising. Stars are believed to form as a result of the gravitational collapse of a portion of a molecular cloud. Theory predicts that the cloud core in which the star is formed will be cold, dense and possess hundreds of magnitudes of extinction, rendering it opaque at visible and near-infrared wavelengths. C
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43

Rey, Raposo Ramon. "The interplay between stellar feedback and galactic environment in molecular clouds." Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/21022.

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In this thesis we address the problem of understanding the star formation process in giant molecular clouds in a galactic context. Most simulations of molecular clouds to date use an oversimplified set of initial conditions (turbulent spheres/boxes or colliding flows). Full galactic scale models are able to generate molecular clouds with complex morphologies and velocity fields but they fail to reproduce in detail the effects that occur at sub-pc scales (e.g. stellar feedback). Our goal is to build the bridge between these two scenarios, and to model the star formation process in molecular clo
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44

Lang, William Jonathan. "Molecular clouds in the #lambda#-orionis ring : a new CO survey." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389119.

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45

Zakri, Wafa. "A Search for Large Amplitude Variability in the Orion Molecular Clouds." University of Toledo / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1596736274108871.

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46

Richter, Philipp. "FUV absorption spectroscopy of interstellar molecular hydrogen towards the Magellanic clouds /." Aachen : Shaker, 1999. http://catalogue.bnf.fr/ark:/12148/cb37739235j.

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Dissertation--Mathematisch-Naturwissenschaftliche Fakultät--Bonn--Rheinische Friedrich-Wilhelms-Universität, 1999. Titre de soutenance : FUV spectroscopy of interstellar molecular hydrogen towards the Magellanic clouds.<br>FUV = far ultraviolet. Bibliogr. p. 83-85.
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47

Maloney, Philip Richard. "Global properties of molecular clouds and the interstellar medium in galaxies." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184271.

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Molecular gas in other galaxies is generally studied by observations of CO emission; a conversion from CO integrated intensity to H₂ column density must be made. Modelling of the emission from an ensemble of molecular clouds shows that these conversion factors are sensitive to temperature, so that molecular gas masses in galaxies with high star formation rates have probably been overestimated. Conversely, models of molecular clouds in low metallicity systems (such as irregular galaxies) demonstrate that the use of CO as a tracer can severely underestimate the molecular gas abundance. The obser
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48

Moorhouse, Alan. "Molecular hydrogen line ratios as probes of shocks in dense clouds." Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/28656.

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This thesis is concerned with the structure of shocks occurring in dense regions of molec?ular clouds. These shocks are associated with the outflows from young stars, Herbig-Haro objects, expanding HII regions and the interaction of supernovae remnants with molecu?lar clouds. Momentum, mass and energy are imparted to the cloud. A full understanding of the shock process is thus needed if we are to understand the structure of molecular clouds and the impact on star formation. Emission from the near-infrared transitions of molecular hydrogen is commonly excited in these shocks. A major puzzle is
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49

Valdivia, Valeska. "Impact of radiative transfer and chemistry on the formation of molecular clouds." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066709/document.

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Le milieu interstellaire (MIS) est un système extrêmement complexe. Il correspond à une échelle intermédiaire entre les étoiles et les galaxies. Le gaz interstellaire est présent dans toute la galaxie, remplissant l’espace entre les étoiles. Une grande diversité de processus couplés, comme la gravité, le champs magnétiques, la turbulence et la chimie, participe à son évolution, faisant de la modélisation du MIS un problème ardu. Une description correcte du MIS nécessite un bon traitement des équations de la magnetohydrodynamique (MHD), de la gravité, du bilan thermique et de
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50

Smith, Rowan Johnston. "The earliest fragmentation in molecular clouds : and its connection to star formation." Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/929.

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Stars are born from dense cores of gas within molecular clouds. The exact nature of the connection between these gas cores and the stars they form is an important issue in the field of star formation. In this thesis I use numerical simulations of molecular clouds to trace the evolution of cores into stars. The CLUMPFIND method, commonly used to identify gas structures is tested. I find that the core boundaries it yields are unreliable, but in spite of this, the same profile is universally found for the mass function. To facilitate a more robust definition of a core, a modified clumpfind algori
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