Download or read book Gas Flow from Star Forming Cores Onto Protostellar Disks written by Loraine Sandoval Ascencio and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigating the dynamics in protostellar disks is key to understanding the evolution of protostars, their developing structure, and the formation of planets. The components of a class 0/I Young Stellar Object (YSO) such as L1527 include the protostar, outflowing gas, a protostellar disk, and a gaseous infalling envelope. The protostar accretes mass which initially travels from the envelope and then into the disk. Studies have shown the outer disk regions of young YSO systems may exhibit shocks at the disk-envelope boundary. This causes deviations from simple dynamics such as circular Keplerian motions and can govern the size of the eventual planetary system. RadChemT developed by Flores-Rivera et al. (2021) modeled L1527 to have an infalling rotating envelope and a circular Keplerian disk inside of the disk radius, 75 au. In this work, we model shocks and implement elliptical orbits post-shock to describe C18O (2-1) gas motions inside the disk for the RadChemT model. We generate spectral line cubes and position-velocity diagrams to visualize and interpret our model. The results of the updated modeling method are compared with the prior method and observed data from the Atacama Large Millimeter/submillimeter Array (ALMA). Since L1527 is an approximately edge-on system, we can resolve the kinematics and shock physics in diagrams. Generating a consistent model enables us to constrain the protostar's mass using Doppler velocity techniques, explain similar motions in other YSOs, and potentially provide novel clues on planet formation.
Download or read book Protostars and Planets IV written by Vincent Mannings and published by . This book was released on 2000 with total page 1470 pages. Available in PDF, EPUB and Kindle. Book excerpt: Click here for the online version of this book! This title, out of print in 2008, is now available free of charge, in it's entirety, online through the University of Arizona Press! Both a textbook and a status report for every facet of research into the formation of stars and planets, Protostars and Planets IV brings together 167 authors who report on the most significant advances in the field since the publication of the previous volume in 1993. Protostars and Planets IV reflects improvements in observational techniques and the availability of new facilities such as the Infrared Space Observatory, the refurbished Hubble Space Telescope, and the 10-m Keck telescopes. Advances in computer technology and modeling methods have benefited theoretical studies of molecular clouds, star formation, and jets and disks, while recent analyses of meteorites yield important insights into conditions and processes within our Sun's early protoplanetary disk. The 49 chapters describe context and progress for observational and theoretical studies of the structure, chemistry, and dynamics of molecular clouds; the collapse of cores and the formation of protostars; the formation and properties of young binary stars; the properties of winds, jets, and molecular outflows from young stellar objects; the evolution of circumstellar envelopes and disks; grain growth in disks and the formation of planets; and the properties of the early Solar nebula. Protostars and Planets IV is also the first book to include chapters describing the discoveries of extrasolar planets, brown dwarfs, and Edgeworth-Kuiper Belt objects, and the first to include high-resolution optical and near-infrared images of protoplanetary disks. Protostars and Planets IV is an unsurpassed reference not only for established researchers but also for younger scientists whose imagination and work will lead to tomorrow's discoveries.
Download or read book The Formation of Stars written by Steven W. Stahler and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 865 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Accretion Processes in Star Formation written by Lee Hartmann and published by Cambridge University Press. This book was released on 2000-11-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first comprehensive account of the dynamical processes in the formation of stars and disks from which planets ultimately form.
Download or read book Molecular Clouds And Star Formation Proceedings Of The 7th Guo Shoujing Summer School On Astrophysics written by Yuan Chi and published by World Scientific. This book was released on 1995-11-16 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is composed of four major in-depth yet pedagogic review chapters on the subject of star formation, written by the foremost researchers in the field. Recent infrared and millimeter radio observations are respectively reviewed by Charlie Lada and Phil Myers, both of Harvard-Smithsonian Center for Astrophysics. The theoretical work is reviewed by Frank Shu of UC-Berkeley on the gravitational collapse of dense cores in a giant molecular cloud to form sunlike stars and Bruce Elmegreen of IBM-Watson on the gravitational instability, leading to large-scale star formation. They have written at a level most suitable for graduate students or young researchers who want to develop their research interest in the field, with the most complete literature survey to date. This volume is not an ordinary conference proceedings, but a textbook to be used in graduate study in astrophysics. The volume also includes other short and interesting contributions from Doug Lin of UC-Santa Cruz, Paul Ho of Harvard-Smithsonian, Masa Hayashi of Tokyo University, Debra Elmegreen of Vassar, Jing-Yao Hu of Beijing Observatory, Guo-Xuan Sung of Shanghai Observatory, Chi Yuan of CCNY and ASIAA, and Wen-Ping Chen of Central University, Taiwan.
Download or read book Protostars and Planets VI written by Henrik Beuther and published by University of Arizona Press. This book was released on 2014-12-18 with total page 945 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of a conference held in Heidelberg, Germany, July 15-20, 2013.
Download or read book Star Forming Regions written by International Astronomical Union. Symposium and published by Springer. This book was released on 1987 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 115th Symposium of the International Astronomical Union held in Tokyo, Japan, November 11-15, 1985
Download or read book Protostars and Planets V written by Bo Reipurth and published by University of Arizona Press. This book was released on 2007 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt: '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.
Download or read book A Decade of Hubble Space Telescope Science written by Space Telescope Science Institute (U.S.). Symposium and published by Cambridge University Press. This book was released on 2003-06-26 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hubble Space Telescope has made some of the most dramatic discoveries in the history of astronomy. From its vantage point 600km above the Earth, Hubble is able to capture images and spectra that would be difficult or impossible to obtain from the ground. This volume represents some of the most important scientific achievements of the Hubble Space Telescope in its first decade of operation. Written by world experts, this is an indispensable collection of review articles for researchers and graduate students.
Download or read book Physical Processes in Circumstellar Disks around Young Stars written by Paulo J. V. Garcia and published by University of Chicago Press. This book was released on 2011-04-15 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Circumstellar disks are vast expanses of dust that form around new stars in the earliest stages of their birth. Predicted by astronomers as early as the eighteenth century, they weren’t observed until the late twentieth century, when interstellar imaging technology enabled us to see nascent stars hundreds of light years away. Since then, circumstellar disks have become an area of intense study among astrophysicists, largely because they are thought to be the forerunners of planetary systems like our own—the possible birthplaces of planets. This volume brings together a team of leading experts to distill the most up-to-date knowledge of circumstellar disks into a clear introductory volume. Understanding circumstellar disks requires a broad range of scientific knowledge, including chemical processes, the properties of dust and gases, hydrodynamics and magnetohydrodynamics, radiation transfer, and stellar evolution—all of which are covered in this comprehensive work, which will be indispensable for graduate students, seasoned researchers, or even advanced undergrads setting out on the study of planetary evolution.
Download or read book Physical Processes in Fragmentation and Star Formation written by Roberto Capuzzo-Dolcetta and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent years have witnessed the expansion and multiplication of the observations of star formation and fragmentation accompanied by a consequent growth in the study of the underlying physical processes, the chemistry, the sites, the times, etc. Moreover, recent studies have shown that the formation of stars is likely to share many features with the formation of other self-gravitating objects. The present volume, therefore, discusses the formation of such objects in a systematic and comparative manner.
Download or read book Cores to Clusters written by M.S. Nanda Kumar and published by Springer Science & Business Media. This book was released on 2008-04-07 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was with pleasure that CAUP became for three days the core to the cloud of star formation experts all over the world. Close to the celebration of its 15th anniversary – therefore still in the early stages of institutional evolution – we are proud of our multiple activities in Astronomy: a productive research centre, classi?ed as “Institution of excellence” within the Portuguese research units, but also an “Institution of Public Utility” as recognised by the Government. Fifteen years ago we choose to play a role not only in research, as expected from any research centre but also in the training of the future astronomers and the promotion of science and scienti?c culture. This choice is clearly stated in our by-laws and also in the multiple activities we have carried out since. Along the years we have organized on a regular basis international Workshops similar to “Cores to Clusters”. Sometimes we have chosen to organize int- national conferences of a larger size. On other occasions the choice has been for smaller and more informal discussion meetings. Or even doctoral schools with very different objectives. In common all those meetings have always had, besides the formal registered participants, a group of informal participants, our undergraduate students of Astronomy, so eager to be in touch with the real world.
Download or read book Heat Transport and Energetics of the Earth and Rocky Planets written by Anne Hofmeister and published by Elsevier. This book was released on 2019-11-22 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat Transport and Energetics of the Earth and Rocky Planets provides a better understanding of the interior of the Earth by addressing the processes related to the motion of heat in large bodies. By addressing issues such as the effect of self-gravitation on the thermal state of the Earth, the effect of length-scales on heat transport, important observations of Earth, and a comparison to the behavior of other rocky bodies, readers will find clearly delineated discussions on the thermal state and evolution of the Earth. Using a combination of fundamentals, new developments and scientific and mathematical principles, the book summarizes the state-of-the-art. This timely reference is an important resource for geophysicists, planetary scientists, geologists, geochemists, and seismologists to gain a better understanding of the interior, formation and evolution of planetary bodies.
Download or read book The Interplay Between Massive Star Formation the ISM and Galaxy Evolution written by D. Kunth and published by Atlantica Séguier Frontières. This book was released on 1996 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book From Gas and Dust to Protostars written by Steve Mairs and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Though there has been a considerable amount of work investigating the early stages of low-mass star formation in recent years, the general theory is only broadly understood and several open questions remain. Specifically, the dominant physical mechanisms which connect large-scale molecular cloud structures, intermediate-scale filamentary gas flows, and small-scale collapsing prestellar envelopes in the interstellar medium are poorly constrained. Even for an individual forming protostar, the evolution of the mass accretion rate from the envelope onto the central object is debated with little observational evidence to help guide the theoretical framework. In addition, with the development of new technology such as the continuum imaging instrument in operation at the James Clerk Maxwell Telescope (JCMT), the Submillimetre Common User Bolometer Array 2 (SCUBA-2), the best practices for data reduction and image calibration for ground-based, submillimetre wavelength observations are still being investigated. In this dissertation, I address facets of these open questions in five main projects with an overarching focus on the flow of material from the largest to the smallest scales in a molecular cloud. By performing synthetic observations of a numerical simulation of a turbulent molecular cloud, I investigate the nature of prestellar envelopes and find evidence of larger mass reservoirs that form filamentary structures and feed cluster formation. Then, after robustly investigating and suggesting improvements for ground-based, submillimetre data reduction techniques, I continue to probe the connection between larger and smaller scales by characterising structure fragmentation in the Southern Orion A Molecular Cloud from the perspective of 850 m continuum data. Finally, I follow star forming material to even smaller scales by exploring the evolution of the mass accretion rate onto individual protostars. This examination has required designing and implementing unprecedented spatial alignment and flux calibration techniques at 850 m. Using these newly calibrated images, I am able to identify several candidate sources that show evidence for submillimetre variability, suggesting changes in protostellar accretion rates over several year timescales.
Download or read book Galactic and Extragalactic Star Formation written by Ralph E. Pudritz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in the instrumentation used to observe star forming regions in both our own Milky Way and in external galaxies have transformed the subject from a phenomenological pursuit into an increasingly unified, physical science. High resolution centimetre, millimetre, infrared, and optical studies of local star forming clouds have allowed us to probe the physics of star formation down to spatial scales approaching those of the solar system. These developments make it possible to better constrain the basic physical processes underlying star formation itself. At the same time, these new instruments have placed extragalactic studies on a footing detailed enough to allow comparison with star forming regions within our own galaxy. This revolution means that we will soon be able to link the physics of local star forming regions to the global star forming properties of galaxies. The entire structure of this NATO Advanced Study Institute was designed to explore this new view of the subject. This Institute on "Galactic and Extragalactic Star Formation" was held from June 21 -July 4, 1987 at the Conference Centre in the village of Whistler, British Columbia, Canada. The informal atmosphere of this lovely mountain resort stim ulated many valuable scientific exchanges. The Institute was funded by a major grant from NATO Scientific Affairs. Additional financial and I.I1oral assistance was provided by the Canadian Institute for Theoretical Astrophysics (CITA) and Mc Master University.
Download or read book Frontiers Of Space And Ground Based Astronomy written by Willem Wamsteker and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 721 pages. Available in PDF, EPUB and Kindle. Book excerpt: ROSAT Observations G. HASINGER Max-Planck-Institut flir extraterrestrische Physik, D-85740 Garching, Germany Abstract. This review describes the most recent advances in the study of the extragalactic soft X-ray background and what we can learn about its constituents. The deepest pointed observations with the ROSAT PSPC are discussed. The logN-logS relation is presented, which reaches to the faintest X-ray fluxes and to the highest AGN surface densities ever achieved. The N(>S) relation shows a 2 density in excess of 400 deg- at the faintest fluxes and a flattening below the Einstein Deep Survey limit. About 60% of the extragalactic background has been resolved in the deepest field. Detailed source spectra and first optical and radio identifications will be discussed. The results are put into perspective of the higher energy X -ray background. Key words: X-rays, background radiations, active galactic nuclei. 1. Introduction The extragalactic X-ray background (XRB), discovered about 30 years ago, has been studied extensively with many X-ray experiments, in particular with the satel lites HEAO I and II (see ego Boldt 1987) and with ROSAT (e. g. Hasinger et aI. , 1993). Figure 1 shows a compilation of some of the most recent spectral measure ments for the X-ray background. Over the energy range from 3 to about 100 keY its spectrum can be well approximated by an optically thin thermal bremsstrahlung model with kT ~ 40 keY, while at lower X-ray energies a steepening into a new component has been observed observed (e. g.
