Download or read book The Interstellar Abundance of the Hydrogen Molecule written by R. J. Gould and published by . This book was released on 1965 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 The Interstellar Abundance of the Hydrogen Molecule written by ROBERT J. GOULD and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interstellar Abundance of the Hydrogen Molecule I Basic Processes written by Robert J. Gould and published by . This book was released on 1963 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis is given of the various processes which determine the molecular concentration in H I cloudshe most important mechanism for forming molecular hydrogen is association on the surface of the interstellar grains, the characteristic time for conversion to molecular form being about 100 million years. It is shown that the range of grain temperatures where this recombination reaction is efficient is coincident with the range 5-20 K which is expected to result from the interaction with the interstellar radiation field. It is estimated that the efficiency (recombination coefficient) of the process is between 0.1 and 1. Regarding dissociative processes, photodissociation through the forbidden transition between the two Heitler London states of the molecule, previously thought to be most important, is shown to be negligible. Ionization and dissociation of a cloud by random encounters with O and B stars occurs about once every 100 million years, so that if the grain recombination process is operative a balance results in which the molecular abundance is roughly comparable to the observed atomic concentration. The cooling properties of molecular hydrogen are discussed. (Author).
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 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 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 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 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 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 The Formation of Molecular Hydrogen in the Interstellar Medium written by Farahjabeen Islam and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interstellar Grains written by Rensselaer Polytechnic Institute and published by . This book was released on 1967 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Collisions in the Interstellar Medium written by David Flower and published by Cambridge University Press. This book was released on 2007-03-22 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the interstellar medium - the space between the stars in galaxies - new stars are born from material that is replenished by the debris ejected by stars when they die. This book is a comprehensive manual for studying the collisional and radiative processes observed in the interstellar medium. This second edition has been thoroughly updated and extended to cover related topics in radiation theory. It considers the chemistry of the interstellar medium both at the present epoch and in the early Universe, and discusses the physics and chemistry of shock waves. The methods of calculation of the rates of collisional excitation of interstellar molecules and atoms are explained, emphasising the quantum mechanical method. This book will be ideal for researchers involved in the interstellar medium and star formation, and physical chemists specialising in collision theory or in the measurement of the rates of collision processes.
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 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 Reactions of Hydrogen and Oxygen Atoms on Interstellar Grain Analogues written by and published by . This book was released on 2012 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
