Water Snowline in Protoplanetary Disks


Book Description

This book presents pioneering work on a critical observational test of the planet formation theory based on the theoretical study of the water snowline, beyond which water takes the form of ice, in the protoplanetary disks – the place where planets are formed. Since the water snowline is thought to divide the regions of rocky and gas-giant planet formation, the location of the snowline is essential for the planet formation process. The book proposes a novel method to locate the snowlines using high-dispersion spectroscopic observations of water vapor lines, which is based on in sophisticated chemical modeling and line radiative transfer calculations. The author obtained the water vapor distribution in the disks using the chemical reaction network, which includes photoreactions and gas–grain interactions. The simulated transition lines of water vapor in the disks demonstrate that relatively weak transition lines with moderate excitation energies are the best tracers of water snowline. Furthermore, the author observed submillimeter lines of water vapor in a disk using ALMA (Atacama Large Millimeter/submillimeter Array) to obtain the upper limit of the line fluxes with the highest sensitivity to date. These unprecedented findings are important in locating the snowlines in the disks, and the method goes a long way toward achieving a comprehensive understanding of the planet formation processes as well as of the origin of water on rocky planets, including our Earth, based on future observations using ALMA and SPICA (Space Infrared Telescope for Cosmology and Astrophysics).




Protostars and Planets VI


Book Description

Proceedings of a conference held in Heidelberg, Germany, July 15-20, 2013.




Astrophysics of Planet Formation


Book Description

Concise and self-contained, this textbook gives a graduate-level introduction to the physical processes that shape planetary systems, covering all stages of planet formation. Writing for readers with undergraduate backgrounds in physics, astronomy, and planetary science, Armitage begins with a description of the structure and evolution of protoplanetary disks, moves on to the formation of planetesimals, rocky, and giant planets, and concludes by describing the gravitational and gas dynamical evolution of planetary systems. He provides a self-contained account of the modern theory of planet formation and, for more advanced readers, carefully selected references to the research literature, noting areas where research is ongoing. The second edition has been thoroughly revised to include observational results from NASA's Kepler mission, ALMA observations and the JUNO mission to Jupiter, new theoretical ideas including pebble accretion, and an up-to-date understanding in areas such as disk evolution and planet migration.




The Formation of Stars


Book Description

This book is a comprehensive treatment of star formation, one of the most active fields of modern astronomy. The reader is guided through the subject in a logically compelling manner. Starting from a general description of stars and interstellar clouds, the authors delineate the earliest phases of stellar evolution. They discuss formation activity not only in the Milky Way, but also in other galaxies, both now and in the remote past. Theory and observation are thoroughly integrated, with the aid of numerous figures and images. In summary, this volume is an invaluable resource, both as a text for physics and astronomy graduate students, and as a reference for professional scientists.




Protoplanetary Dust


Book Description

The first comprehensive overview of planet formation for students and researchers in astronomy, cosmochemistry, laboratory astrophysics and planetary sciences.




Accretion Power in Astrophysics


Book Description

Accretion Power in Astrophysics examines accretion as a source of energy in both binary star systems containing compact objects, and in active galactic nuclei. Assuming a basic knowledge of physics, the authors describe the physical processes at work in accretion discs and other accretion flows. The first three chapters explain why accretion is a source of energy, and then present the gas dynamics and plasma concepts necessary for astrophysical applications. The next three chapters then develop accretion in stellar systems, including accretion onto compact objects. Further chapters give extensive treatment of accretion in active galactic nuclei, and describe thick accretion discs. A new chapter discusses recently discovered accretion flow solutions. The third edition is greatly expanded and thoroughly updated. New material includes a detailed treatment of disc instabilities, irradiated discs, disc warping, and general accretion flows. The treatment is suitable for advanced undergraduates, graduate students and researchers.




Encyclopedia of Astrobiology


Book Description

The interdisciplinary field of Astrobiology constitutes a joint arena where provocative discoveries are coalescing concerning, e.g. the prevalence of exoplanets, the diversity and hardiness of life, and its increasingly likely chances for its emergence. Biologists, astrophysicists, biochemists, geoscientists and space scientists share this exciting mission of revealing the origin and commonality of life in the Universe. The members of the different disciplines are used to their own terminology and technical language. In the interdisciplinary environment many terms either have redundant meanings or are completely unfamiliar to members of other disciplines. The Encyclopedia of Astrobiology serves as the key to a common understanding. Each new or experienced researcher and graduate student in adjacent fields of astrobiology will appreciate this reference work in the quest to understand the big picture. The carefully selected group of active researchers contributing to this work and the expert field editors intend for their contributions, from an internationally comprehensive perspective, to accelerate the interdisciplinary advance of astrobiology.




The Planet Factory


Book Description

Forget about rockets to Mars – the future of space science lies with the search for exoplanets Twenty years ago, the search for planets outside the Solar System was the preserve of science-fiction writers. Now it's one of the fastest-growing fields in astronomy, with thousands of exoplanets discovered to date, and the number rising fast. These new-found worlds are more alien than anything in fiction. Planets larger than Jupiter with years lasting a week; others with two suns lighting their skies, or with no sun at all. Planets with diamond mantles supporting oceans of tar; possible Earth-sized worlds with split hemispheres of perpetual day and night; waterworlds drowning under global oceans and volcanic lava planets awash with seas of magma. The discovery of this diversity is just the beginning. There is a whole galaxy of possibilities. The Planet Factory tells the story of these exoplanets. What can we learn about these faraway surface environments and planetary atmospheres? And do the results hint at the tantalising possibility of alien life?




Planet Formation and Panspermia


Book Description

An in-depth view of the panspermia hypothesis examined against the latest knowledge of planetary formation and related processes. Panspermia is the concept that life can be passively transported through space on various bodies and seed, habitable planets and moons, which we are beginning to learn may exist in large numbers. It is an old idea, but not popular with those who prefer that life on Earth started on Earth, an alternative, also unproven hypothesis. This book updates the concept of panspermia in the light of new evidence on planet formation, molecular clouds, solar system motions, supernovae ejection mechanisms, etc. Thus, it is to be a book about newly understood prospects for the movement of life through space. The novel approach presented in this book gives new insights into the panspermia theory and its connection with planetary formation and the evolution of galaxies. This offers a good starting point for future research proposals about exolife and a better perspective for empirical scrutiny of panspermia theory. Also, the key to understanding life in the universe is to understand that the planetary formation process is convolved with the evolution of stellar systems in their galactic environment. The book provides the synthesis of all these elements and gives the readers an up-to-date insight on how panspermia might fit into the big picture. Audience Given the intrinsic interdisciplinary nature of the panspermia hypothesis the book will have a wide audience across various scientific disciplines covering astronomy, biology, physics and chemistry. Apart from scientists, the book will appeal to engineers who are involved in planning and realization of future space missions.




Protostars and Planets V


Book Description

'Protostars and Planets V' builds on the latest results from recent advances in ground and space-based astronomy and in numerical computing techniques to offer the most detailed and up-to-date picture of star and planet formation - including the formation and early evolution of our own solar system.