Download or read book High Resolution Observations of 36 GHz Class I Methanol Masers at Sites of 6 7 GHz Class II Methanol Masers in Star Forming Regions written by Jared Hennen and published by . This book was released on 2012 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis we present high angular resolution data on 36 GHz Class I methanol masers associated with sites of 6.7 GHz Class II methanol masers. We observed twenty-three 36 GHz Class I methanol masers in seven star forming regions with the Jansky Very Large Array radio telescope. Our observations have made possible the first high angular resolution maps of 36 GHz masers in several star forming regions, and demonstrated cases where the morphology is highly suggestive of arcs and other structures known to be found at shock interfaces in such regions. The two classes of methanol masers are created through different excitation processes, and occur in different parts of star forming regions. We find that strong 6.7 GHz Class II maser sites are likely associated with weak 36 GHz Class I masers, in agreement with a similar anti-correlation between 44 GHz Class I and 6.7 GHz Class II methanol masers in the literature. However, there is a correlation between 95 GHz Class I and 6.7 GHz Class II masers in the literature. This points to the need for a larger set of high angular resolution data and improved theoretical models of methanol maser pumping and propagation. We find that the center velocities (vLSR) of the observed 36 GHz masers are quite close to the vLSR of 6.7 GHz masers, and in some cases may be closer to the systemic velocity of the region than the vLSR of the 6.7 GHz masers. This could be due to such 36 GHz masers being located at the base of outflows close to the location of the protostar. Finally, comparison of spectral profiles indicates that the strongest 36 GHz masers may lie closer to the 6.7 GHz masers. In summary, such high angular resolution observations that allow for the comparison of the two classes of methanol masers provide a powerful tool to study star forming regions.
Download or read book Insights Into High Mass Star Formation from Methanol Maser Observations written by Hontas Freeman Farmer and published by . This book was released on 2013 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present high angular resolution data on Class I and Class II methanol masers, together with other tracers of star formation like H2O masers, ultracompact (UC) ionized hydrogen (H II) regions, and 4.5 μm infrared sources, taken from the literature. The aim is to study what these data tell us about the process of high mass star formation; in particular, whether disk-outflow systems are compatible with the morphology exhibited by Class I and Class II methanol masers. Stars form in the dense cores inside molecular clouds, and while the process of the formation of stars like our Sun is reasonably well understood, details of the formation of stars with masses eight times that of our Sun or greater, the so-called high mass stars, remain a mystery. Being compact and bright sources, masers provide an excellent way to observe high mass star forming regions. In particular, Class II methanol masers are found exclusively in high mass star forming regions. Based on the positions of the Class I and II methanol and H2O masers, UC H II regions and 4.5 μm infrared sources, and the center velocities (vLSR) of the Class I methanol and H2O masers, compared to the vLSR of the Class II methanol masers, we propose three disk-outflow models that may be traced by methanol masers. In all three models, we have located the Class II methanol maser near the protostar, and the Class I methanol maser in the outflow, as is known from observations during the last twenty years. In our first model, the H2O masers trace the linear extent of the outflow. In our second model, the H2O masers are located in a circumstellar disk. In our third model, the H2O masers are located in one or more outflows near the terminating shock where the outflow impacts the ambient interstellar medium. Together, these models reiterate the utility of coordinated high angular resolution observations of high mass star forming regions in maser lines and associated star formation tracers.
Download or read book Astrophysical Masers IAU S336 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2018-09-13 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes state of the art observations and theories pertaining to astrophysical masers and their environments, for graduate students and researchers.
Download or read book Astrophysical Masers and Their Environments IAU S242 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2008-02-14 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astrophysical masers, naturally occurring microwave and radio-wave emissions, provide an important tool to investigate astrophysical environments. Several thousand maser sources have been observed in the interstellar medium and star formation regions, in the expanding winds from evolved stars, in the compressed shells of supernovae remnants, in comets and in the centers of galaxies. Masers are also useful for studying the structure and dynamics of our own galaxy, while masers in other galaxies are now used for cosmological studies and studies of galactic nuclei. This volume contains the latest research on the topic as presented at IAU Symposium 242, only the third international symposium on astrophysical masers. Over 125 astronomers from 18 different countries gathered in Alice Spring, Australia, for discussions on maser research.
Download or read book Maser Sources in Astrophysics written by Malcolm Gray and published by Cambridge University Press. This book was released on 2012-04-26 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written for postgraduates and researchers, this is an up-to-date survey of astrophysical maser sources and their use as astronomical tools.
Download or read book Astronomy Reports written by and published by . This book was released on 1999 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book VLBI Observations of 6 7 and 12 2 GHz Methanol Masers Toward High Mass Star forming Regions written by V. Minier and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alcohols Advances in Research and Application 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alcohols: Advances in Research and Application: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Alcohols. The editors have built Alcohols: Advances in Research and Application: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Alcohols in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Alcohols: Advances in Research and Application: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1995 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interferometry and Synthesis in Radio Astronomy written by A. Richard Thompson and published by Wiley-Interscience. This book was released on 1986-04-28 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unified description of the theory and practice of radio interferometry and synthesis mapping techniques as they apply to astronomy and geology. Beginning with an historical review, it goes on to provide a detailed description of all aspects of radio inferometry, from basic principles through instrumental design to data reduction. Over 450 original papers and monographs are cited.
Download or read book Astrophysics in a Nutshell written by Dan Maoz and published by Princeton University Press. This book was released on 2016-02-23 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ideal one-semester astrophysics introduction for science undergraduates—now expanded and fully updated Winner of the American Astronomical Society's Chambliss Award, Astrophysics in a Nutshell has become the text of choice in astrophysics courses for science majors at top universities in North America and beyond. In this expanded and fully updated second edition, the book gets even better, with a new chapter on extrasolar planets; a greatly expanded chapter on the interstellar medium; fully updated facts and figures on all subjects, from the observed properties of white dwarfs to the latest results from precision cosmology; and additional instructive problem sets. Throughout, the text features the same focused, concise style and emphasis on physics intuition that have made the book a favorite of students and teachers. Written by Dan Maoz, a leading active researcher, and designed for advanced undergraduate science majors, Astrophysics in a Nutshell is a brief but thorough introduction to the observational data and theoretical concepts underlying modern astronomy. Generously illustrated, it covers the essentials of modern astrophysics, emphasizing the common physical principles that govern astronomical phenomena, and the interplay between theory and observation, while also introducing subjects at the forefront of modern research, including black holes, dark matter, dark energy, and gravitational lensing. In addition to serving as a course textbook, Astrophysics in a Nutshell is an ideal review for a qualifying exam and a handy reference for teachers and researchers. The most concise and current astrophysics textbook for science majors—now expanded and fully updated with the latest research results Contains a broad and well-balanced selection of traditional and current topics Uses simple, short, and clear derivations of physical results Trains students in the essential skills of order-of-magnitude analysis Features a new chapter on extrasolar planets, including discovery techniques Includes new and expanded sections and problems on the physics of shocks, supernova remnants, cosmic-ray acceleration, white dwarf properties, baryon acoustic oscillations, and more Contains instructive problem sets at the end of each chapter Solutions manual (available only to professors)
Download or read book Cosmic Magnetic Fields written by Richard Wielebinski and published by Springer Science & Business Media. This book was released on 2005-09-13 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: While magnetic fields permeate the universe on all scales, the present book is dedicated to their investigation on the largest scales and affords a balanced account of both theoretical and observational aspects. Written as a set of advanced lectures and tutorial reviews that lead up to the forefront of research, this book offers both a modern source of reference for the experienced researchers as well as a high-level introductory text for postgraduate students and nonspecialist researchers working in related areas.
Download or read book NgVLA written by Eric James Murphy and published by . This book was released on 2018 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Literature 1997 Part 1 written by Astronomisches Rechen-InstitutARI and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1746 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book But it was Fun written by Felix J. Lockman and published by . This book was released on 2007 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
