Download or read book The Abundance of Molecular Hydrogen in Interstellar Gas Clouds written by D. A. Mendis and published by . This book was released on 1968* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Hydrogen in Space written by F. Combes and published by Cambridge University Press. This book was released on 2000-11-06 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first multi-disciplinary review of our new understanding of molecular hydrogen in space, and its role in the early Universe.
Download or read book The Formation of Molecular Hydrogen in the Interstellar Medium written by Benjamin James Irving and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics and Chemistry of the Interstellar Medium written by A. G. G. M. Tielens and published by Cambridge University Press. This book was released on 2005-08-25 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work provides a comprehensive overview of our theoretical and observational understanding of the interstellar medium of galaxies. With emphasis on the microscopic physical and chemical processes in space, and their influence on the macroscopic structure of the interstellar medium of galaxies, the book includes developments in this area of molecular astrophysics. The various heating, cooling, and chemical processes relevant for the rarefied gas and submicron-sized dust grains that constitute the interstellar medium are discussed in detail. This provides a firm foundation for an in-depth understanding of the ionized, neutral atomic, and molecular phases of the interstellar medium. The physical and chemical properties of large polycyclic aromatic hydrocarbon molecules and their role in the interstellar medium are highlighted, and the physics and chemistry of warm and dense photodissociation regions are discussed. This is an invaluable reference source for advanced undergraduate and graduate students, and research scientists.
Download or read book Dust and Chemistry in Astronomy written by T.J Millar and published by Routledge. This book was released on 2019-06-06 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dust is widespread in the galaxy. To astronomers studying stars it may be just an irritating fog, but it is becoming widely recognized that cosmic dust plays an active role in astrochemistry. Without dust, the galaxy would have evolved differently, and planetary systems like ours would not have occurred. To explore and consolidate this active area of research, Dust and Chemistry in Astronomy covers the role of dust in the formation of molecules in the interstellar medium, with the exception of dust in the solar system. Each chapter provides thorough coverage of our understanding of interstellar dust, particularly its interaction with interstellar gas. Aimed at postgraduate researchers, the book also serves as a thorough review of this significant area of astrophysics for practicing astronomers and graduate students.
Download or read book Molecular Clouds written by R. A. James and published by Cambridge University Press. This book was released on 1991-06-28 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of molecular clouds has received increasing interest over recent years, particularly in the UK with the advent of powerful new instruments such as MERLIN and the Maxwell millimetre wave telescope. This book is based on the proceedings of the Seventh Manchester International Astronomy Conference which brought together an international list of speakers to discuss important new developments in this field. The book covers a wide range of topics relevant to the general subject of molecular clouds, with review articles and papers from an impressive list of contributors. Much new work in this area is covered, and consequently this book should become an important reference source for workers in this and related fields.
Download or read book The Formation of Molecular Hydrogen in the Interstellar Medium written by F. Islam and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: H2 is the most abundant molecule in the interstellar medium and forms on the surface of interstellar dust grains. Laboratory studies have been conducted of HD formation on a dust grain analogue, which is a highly-oriented pyrolytic graphite surface held at 15 K, under ultra-high vacuum. The molecules desorb from the surface in a distribution of ro-vibrational states, which are probed using Resonance Enhanced Multi-Photon Ionization Spectroscopy. HD in a particular ro-vibrational state is ionized using laser photons detected by a time-of-flight mass spectrometer. The HD+ ion yields are then data processed to obtain the relative rotational populations of HD formed within one vibrational level and an average rotational temperature can be found. In this thesis, HD formed in vibrational states v = 3 - 7 have been studied. This carries on from previous studies of HD and H2 in the v = 1 and 2 states. Within each vibrational level, the most populated rotational state was found to be J = 1 or 2. The most populated vibrational state was found to be v = 4. The HD experimental results were extrapolated to give the relative ro-vibrational population distribution of nascent H2, which provides a new model for the formation pumping of H2. This new formation pumping model has been implemented into a radiative transfer code, written by Casu and Cecchi-Pestellini, which takes into account formation, radiative and collisional pumping mechanisms to calculate the total population distribution of H2 in an interstellar cloud and to generate H2 spectra. The sensitivity of the H2 spectra to the physical conditions of interstellar dark clouds, such as cloud density and temperature, has been investigated. H2 spectra generated using the new experimentally-derived formation pumping model has also been compared to H2 spectra generated using other established, theoretically-derived formation pumping models.
Download or read book Chemistry Between the Stars written by Richard H. Gammon and published by . This book was released on 1976 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interstellar Medium written by James Lequeux and published by Springer Science & Business Media. This book was released on 2005-08-29 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describing interstellar matter in our galaxy in all of its various forms, this book also considers the physical and chemical processes that are occurring within this matter. The first seven chapters present the various components making up the interstellar matter and detail the ways that we are able to study them. The following seven chapters are devoted to the physical, chemical and dynamical processes that control the behaviour of interstellar matter. These include the instabilities and cloud collapse processes that lead to the formation of stars. The last chapter summarizes the transformations that can occur between the different phases of the interstellar medium. Emphasizing methods over results, The Interstellar Medium is written for graduate students, for young astronomers, and also for any researchers who have developed an interest in the interstellar medium.
Download or read book Giant Molecular Clouds in the Galaxy written by P. M. Solomon and published by Elsevier. This book was released on 2013-10-22 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Giant Molecular Clouds in the Galaxy: Third Gregynog Astrophysics Workshop covers the proceedings of the 1977 Third Gregynog Astrophysics Workshop on Giant Molecular Clouds (GMC), held at the University of Wales. This book is organized into 11 parts encompassing 33 chapters. After a brief introduction to the significant features of GMC, this book goes on examining radio, millimeter, and galactic center observations of GMC, along with their infrared properties and kinematics. Other parts deal with the water sources in GMC; time variation in interstellar water masers; and the relation of HII regions to molecular clouds. The remaining parts discuss the evolution of interstellar molecular clouds and the role of magnetic fields in the collapse of protostellar gas clouds. These parts also cover the chemistry of interstellar molecules containing nitrogen and the search for other planetary systems. This book will prove useful to cloud scientists, physicists, astronomers, and researchers.
Download or read book Physics of the Interstellar and Intergalactic Medium written by Bruce T. Draine and published by Princeton University Press. This book was released on 2011 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential resource for graduate students and astrophysicists This is a comprehensive and richly illustrated textbook on the astrophysics of the interstellar and intergalactic medium—the gas and dust, as well as the electromagnetic radiation, cosmic rays, and magnetic and gravitational fields, present between the stars in a galaxy and also between galaxies themselves. Topics include radiative processes across the electromagnetic spectrum; radiative transfer; ionization; heating and cooling; astrochemistry; interstellar dust; fluid dynamics, including ionization fronts and shock waves; cosmic rays; distribution and evolution of the interstellar medium; and star formation. While it is assumed that the reader has a background in undergraduate-level physics, including some prior exposure to atomic and molecular physics, statistical mechanics, and electromagnetism, the first six chapters of the book include a review of the basic physics that is used in later chapters. This graduate-level textbook includes references for further reading, and serves as an invaluable resource for working astrophysicists. Essential textbook on the physics of the interstellar and intergalactic medium Based on a course taught by the author for more than twenty years at Princeton University Covers radiative processes, fluid dynamics, cosmic rays, astrochemistry, interstellar dust, and more Discusses the physical state and distribution of the ionized, atomic, and molecular phases of the interstellar medium Reviews diagnostics using emission and absorption lines Features color illustrations and detailed reference materials in appendices Instructor's manual with problems and solutions (available only to teachers)
Download or read book The Molecular Astrophysics of Stars and Galaxies written by T. W. Hartquist and published by Oxford University Press. This book was released on 1998 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive survey of modern molecular astrophysics. It includes an introduction to molecular spectroscopy and then addresses the main areas of current molecular astrophysics, including galaxy formation, star forming regions, mass loss from young as well as highlyevolved stars and supernovae, starburst galaxies plus the tori and discs near the central engines of active galactic nuclei. All chapters have been written by invited authors who are acknowledged experts in their fields. The thorough editorial process has ensured a uniformly high standard ofexposition and a coherent style. The book is unique in giving a detailed view of its wide-ranging subject. It will provide the standard introduction for research students in molecular astrophysics. The book will be read by research astronomers and astrophysicists who wish to broaden the basis oftheir knowledge or are moving their activities into this burgeoning field. It will enable chemists to learn the astrophysics most related to chemistry as well as instruct physicists about the molecular processes most important in astronomy.
Download or read book Laboratory Astrophysics written by Guillermo M. Muñoz Caro and published by Springer. This book was released on 2018-10-11 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the most recent, relevant, comprehensive and significant aspects in the well-established multidisciplinary field Laboratory Astrophysics. It focuses on astrophysical environments, which include asteroids, comets, the interstellar medium, and circumstellar and circumplanetary regions. Its scope lies between physics and chemistry, since it explores physical properties of the gas, ice, and dust present in those systems, as well as chemical reactions occurring in the gas phase, the bare dust surface, or in the ice bulk and its surface. Each chapter provides the necessary mathematical background to understand the subject, followed by a case study of the corresponding system. The book provides adequate material to help interpret the observations, or the computer models of astrophysical environments. It introduces and describes the use of spectroscopic tools for laboratory astrophysics. This book is mainly addressed to PhD graduates working in this field or observers and modelers searching for information on ice and dust processes.
Download or read book The Interstellar Abundance of the Hydrogen Molecule written by Robert Joseph Gould and published by . This book was released on 1963 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements and Time Evolution of Atomic and Molecular Hydrogen in Interstellar Clouds written by Marko Krco and published by . This book was released on 2015 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: The timescale over which molecular clouds collapse to form stars is of intense scientific interest. It reflects the support mechanisms which slow collapse such as angular momentum, thermal pressure, turbulence, and ambipolar diffusion, and impacts the chemical make up of the resulting stars and surrounding planets. In this doctoral thesis we obtain lower age limits for a set of molecular clouds by studying the ratio between atomic and molecular hydrogen gas. Clouds are initially entirely, or almost entirely composed of atomic hydrogen (HI), but by the time they form stars they are almost entirely composed of molecular hydrogen (H2). We measure H2 column densities using 13 CO and dust extinction as tracers. In the clouds' interiors, the HI gas is sufficiently shielded from the external radiation field that it cools to temperatures of approximately 10K to 50K, at which point it can absorb the background 21 cm emission from the warm galactic ISM. This HI Narrow Self-Absorption (HINSA) is simple to observe, yet difficult to analyze due to the complexity of the background emission. We present a novel new method of analyzing HINSA spectra which for the first time offers sufficient confidence in the derived column densities that a more sophisticated analysis of the HI/H2 ratio in clouds could be undertaken. We have performed the largest survey of HINSA in clouds carried out to date using the Green Bank Telescope (GBT), and the Five College Radio Observatory (FCRAO). We establish HINSA as a useful tool, and with the large body of data acquired, can move to determine the ages of several clouds. We discovered that the observed HINSA column densities were highly dependent on the unknown shape and orientation of each cloud. Thus we developed a geometryindependent method of determining the density distribution function of molecular clouds. A geometry-independent chemical model then allowed us to determine the lower limits to the ages of 23 clumps within 9 molecular clouds.
Download or read book Interaction of Atomic and Molecular Hydrogen on Amorphous Water Ice Surfaces Mimicking Interstellar Dust written by Elie Matar and published by . This book was released on 2009 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among 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).
Download or read book Molecular Astrophysics written by Geerd H.F. Diercksen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 741 pages. Available in PDF, EPUB and Kindle. Book excerpt: and In the IAU Symposium of 1979 devoted to interstellar molecules [8]. Excellent relevant monographs [ 9. 10] . related timely proceedings [ 11] . and recently published elementary textbooks [12. 13] further help to define the pedagogical scope of molecular astrophysics. A significant financial investment has been made in the establishment of ground- and satellite-based observationai facilities for molecuiar astrophysical studies. In the coming years. a wealth of experimental data is bound to accumulate. in which connection close interactions between observers. astrophysical modeliers. and molecular physicists and chemists can play a helpful role in analysis and interpretation. In view of the increasing pace of activity in the field of molecular astrophysics. and in the apparent absence of relevant international meetings since the Liege 1977 and IAU 1979 Symposia. it was deemed appropriate and timely by the organizers to hold a workshop in 1984. Consequently. the NATO Advanced Research Workshop. "Molecular Astrophysics State of the Art and Future Directions". was organized and held at Bad Wlndshelm. West Germany. from 8 to 14 July 1984. The choice of speakers and subject matter of the Workshop was largely subjective. but designed to include most of the generally accepted areas of molecular astrophysical study. Workers from the fields of radio. infrared. and uv-optlcal observations. astrophysical modelling. laboratory spectroscopy. reaction chemistry. collision physics. and theoretical molecular physics and chemistry. were Invited to present survey lectures In their areas of speciality. In addition.
