Author: Jonathan Barnes
Publisher:
ISBN: 9781369846409
Category : Astronomy
Languages : en
Pages : 33
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Book Description
Protostars are stars in their earliest stages of development. They are born in giant molecular clouds of gas that can be as dense as 104 solar masses and as cool as 10K. When the gravity is strong enough, the gas collapses in on itself creating the star. The envelope of gas that surrounds the protostar in its development also plays a role in creating a solar system. Some physical properties such as the mass of the protostar can be gathered by modeling the infalling and rotational motion of the gas of the envelope. [can determine the mass of the growing protostar]. We developed a method to measure protostar masses quickly and conveniently by data-mining the ALMA archive and using automated processing tools. ADMIT is a processing tool that automatically models, via spectral line identification, the infalling and rotational motion, of the gas, with a PV diagram and moment maps including the 2nd moment. We validate our method by modeling the motion of the gas in the L1527 protostar's envelope and comparing to and already known model. This same method should work on other protostar's with ALMA data to determine its mass.
Author: Yoko Oya
Publisher: Springer Nature
ISBN: 9811917086
Category : Science
Languages : en
Pages : 219
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Book Description
This book characterizes the kinematic and chemical structures of disk-forming regions around low-mass protostellar sources and their interplay based on Atacama Large Millimeter/submillimeter Array (ALMA) observations. It describes the chemical evolution of molecules formed in an interstellar gas using the ALMA observations of 5 Sun-like protostars at a spatial resolution of a few tens au scale, which unveils the physical mechanism of star and planetary formation. The book reviews the author’s successful works, focusing on two key findings: (i) A drastic change in the chemical composition of the gas around the centrifugal barrier of the infalling-rotating envelopes, and (ii) the chemical composition in the disk-forming regions, which varies from source to source depending on the chemical characteristics of the parent molecular cloud. These findings are based on the fine characterization of physical structures based on careful kinematic analyses. An additional attraction is the inclusion of the skillful reviews of ALMA observatory and its observation and physical models to describe the observed gas structure.
Author: Loraine Sandoval Ascencio
Publisher:
ISBN:
Category : Astronomy
Languages : en
Pages : 0
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Book Description
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.
Author: Henrik Beuther
Publisher: University of Arizona Press
ISBN: 0816531242
Category : Science
Languages : en
Pages : 945
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Book Description
Proceedings of a conference held in Heidelberg, Germany, July 15-20, 2013.
Author: Vincent Mannings
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1470
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Book Description
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.
Author: Ashraf - Ali
Publisher: Frontiers Media SA
ISBN: 2832500730
Category : Science
Languages : en
Pages : 170
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Book Description
Author: T. W. Hartquist
Publisher: Oxford University Press
ISBN: 9780198501589
Category : Galaxies
Languages : en
Pages : 562
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Book Description
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.
Author: Astronomisches Rechen-InstitutARI
Publisher: Springer Science & Business Media
ISBN: 3642517587
Category : Science
Languages : en
Pages : 1746
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Book Description
Astronomy and Astrophysics Abstracts is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. Two volumes are scheduled to appear per year. Volume 67 records 10,903 papers covering besides the classical fields of astronomy and astrophysics such matters as space flights related to astronomy, lunar and planetary probes and satellites, meteorites and interplanetary matter, X rays and cosmic rays, quasars and pulsars. The abstracts are classified under more than one hundred subject categories thus permitting quick surveying of the bulk of material published on the same topic within six months. For instance, this volume records 119 papers on minor planets, 155 papers on supernovae, and 554 papers on cosmology.
Author:
Publisher:
ISBN:
Category : Astronomy
Languages : en
Pages : 630
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Book Description
Author: Lee Hartmann
Publisher: Cambridge University Press
ISBN: 9780521785204
Category : Science
Languages : en
Pages : 260
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Book Description
This first comprehensive account of the dynamical processes in the formation of stars and disks from which planets ultimately form.
