Download or read book Aperture Synthesis Study of Neutral Hydrogen in the Galaxies NGC 6946 and IC 342 written by and published by . This book was released on 1972 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis observations of netural hydrogen emission in the two spiral galaxies NGC 6946 and IC 342 are presented. The velocity resolution is 21 km/s and the angular resolution is 2 and 4 min of arc for NGC 6946 and IC 342 respectively. Results are presented in the form of contour maps of the integral and mean velocity of the HI profile at each position in the galaxy, as well as a line profile for each galaxy as a whole. Both galaxies evidence a central depression in their HI distributions. The rotation curves have steep central gradients with rather constant velocities once the maximal velocity is reached. The HI mass for NGC 6946 is 21 billion solar mass units and for IC 342 is 15 billion solar mass units, assuming distances of 10.1 and 4.5 Mpc respectively. Other properties are summarized in the table.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973 with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aperture Synthesis Study of Neutral Hydrogen in NGC 2403 and NGC 4236 I Observations II Discussion written by G. S. Shostak and published by . This book was released on 1972 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observational results of an aperture synthesis study of neutral hydrogen in the nearby galaxies NGC 2403 and NGC 4236 are presented. Maps of the integral of the line profile at each position on the galaxies are given, as well as maps showing lines of constant radial velocity determined from the peaks of the profiles. Spatial resolution is 2' of arc; velocity resolution is 21 km/s. In addition, line profiles for the galaxies as a whole and maps of the 1420 MHz continuum radiation from each object are displayed. (Author).
Download or read book Aperture synthesis observations of the neutral hydrogen in the galaxies NGC 4631 NGC 4656 written by I. Weliachew and published by . This book was released on 1977 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Neutral Hydrogen Aperture Synthesis Maps of IC2574 and NGC 7640 written by G. A. Seielstad and published by . This book was released on 1973 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aperture synthesis observations with an angular resolution about 2 arc-min of two late-type galaxies have revealed HI distributions some 1.5 times larger than their photographic images. IC2574, classified as an irregular galaxy, has a well organized velocity field typical of a late spiral galaxy. The major HI concentrations do not correspond with the brightest optical features. A ridge of peculiar velocities of about 10 km/s in the region of the optical 'bar' may indicate streaming motions of gas along the bar. NGC7640 is an SBc galaxy at an inclination of 77 degrees. There is no evidence of any HI halo brighter than 100 degrees K km/s, although there is a suggestion of warping of the plane of the HI layer. (Author).
Download or read book Aperture Synthesis Observations of Neutral Hydrogen in Three Galaxies written by Gerson Seth Shostak and published by . This book was released on 1972 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aperture Synthesis Study of Neutral Hydrogen in the Galaxy M 101 I Observations II Discussion written by D. H. Rogstad and published by . This book was released on 1971 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis observations of neutral hydrogen emission in the spiral galaxy M101 obtained with the Owens Valley twin-element interferometer are presented. The spatial resolution is 4 sec. of arc, and the velocity resolution is 21 km/s. The observations are given in the form of contour maps of the integral and the mean velocity of the HI profile at each position in the galaxy, and a line profile for the galaxy as a whole. A contour map of the 21 cm continuum radiation is also presented. The observations described in another paper (Rogstad and Shostak, 1971) are discussed with the following conclusions: There is a close correspondence between features in the surface density of both light and HI in the galaxy M101. The HI velocity field contains streaming motions which are in agreement with the predictions of the first-order density wave theory of spiral structure. There is evidence for expansion motions of at least 40 km/s in the central region of the galaxy. (Author).
Download or read book The Renaissance of General Relativity in Context written by Alexander S. Blum and published by Springer Nature. This book was released on 2020-11-12 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: This contributed volume explores the renaissance of general relativity after World War II, when it transformed from a marginal theory into a cornerstone of modern physics. Chapters explore key historical processes related to the theory of general relativity, in addition to presenting a thorough treatment of the relevant science behind these episodes. A broad historiographical framework is introduced first, thus providing the broad context in which the given computational approaches and case studies occurred. Written by an international and interdisciplinary group of expert authors, these chapters will bring readers to a more complete understanding of Einstein’s theory. Specific topics include: Social and citation networks The Fock-Infeld dispute Wheeler’s turn to gravitation theory The position of general relativity in theories of fundamental interactions The pursuit of a quantum theory of gravity The emergence of dark matter in relation to cosmological models Institutional frameworks for gravitational wave search in Europe The Renaissance of General Relativity in Context is ideal for historians, philosophers, and sociologists of science. Students and researchers in physics will also be interested in the topics explored.
Download or read book Transactions of the International Astronomical Union Reports on Astronomy written by C. de Jager and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the fifteenth tri-annual reports of the Presidents of the forty Commissions of the International Astronomical Union; it refers to the progress in our discipline during the three years 1970, 1971 and 1972. As compared to earlier volumes a gradual change in character is unmistakable. The ever increasing flow of publications, combined with the obvious necessity to keep the Reports at a reasonable size and price level has gradually forced the Commission Presidents to be more selective than before in drafting their Reports. I have certainly stimulated them into that direction - in order that Reports like these be valuable and lasting, it seems imperative that the individual contributions have the character of a critical overall review, where a fairly complete summary is given of the major develop ments and discoveries of the past three years, and in which the broad developments and new trends be clearly outlined, while at the same time essential problems for future research are identified. With respect to the latter item I have suggested the Commission Presidents to add to their reports a brief section on scientific priorities for future research in the field of their Commissions. In order to save space I have suggested to Commission Presidents that references to published papers are given on the basis of their number in the published issues of Astronomy and Astrophysics Abstracts. For instance, the indication (06. 078. 019) or (AAA 06. 078.
Download or read book Government Reports Announcements written by and published by . This book was released on 1972-08-25 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Literature 1985 Part 1 written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-12-11 with total page 1157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts aims to present a comprehensive documen tation of the literature concerning all aspects of astronomy, astrophysics, and their border fields. It is devoted to the recording, summarizing, and indexing of the relevant publications throughout the world. Astronomy and Astrophysics Abstracts is prepared by a special department of the Astronomisches Rechen-Institut under the auspices of the International Astronomical Union. Volume 39 records literature published in 1985 and received before August 15, 1985. Some older documents which we received late and which are not surveyed in earlier volumes are included too. We acknowledge with thanks contributions of our colleagues all over the world. We also express our gratitude to all organiza tions, observatories, and publishers which provide us with complimentary copies of their publications. On account of the introduction of an object index the scope of index information will be considerably enlarged beginning with this volume. In connection with the subject index an additional source to satisfy the needs of retrieval is opened up. Starting with Volume 33, all the recording, correction, and data processing work was done by means of computers. The recording was done by our technical staff members Ms. Helga Ballmann, Ms. Mona El-Choura, Ms. Monika Kohl, Ms. Sylvia Matyssek. Ms. Karin Burkhardt, Ms. Susanne Schlotelburg, and Mr. Stefan Wagner supported our task by careful proofreading. It is a pleasure to thank them all for their encouragement. Heidelberg, September 1985 The Editors Contents Introduction . . . . . . . . . . . .
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1991-05 with total page 1396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Neutral Hydrogen Study of Close and Wide Galaxy Pairs written by Tyler Eugene Nordgren and published by . This book was released on 1997 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Fields of Galaxies written by A.A. Ruzmaikin and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetism, when extended beyond normal frameworks into cosmic space is characterized by an enormous spatial scale. Because of their large sizes the nature of magnets such as the Earth and the Sun is entirely different from the nature of a horseshoe magnet. The source of cosmic magnetism is associated with the hydrodynamic motions of a highly conductive medium. In this aspect, cosmic magnets resemble a dynamo. However, currents in the dynamo flow along properly ordered wires, while chaotic, turbulent motions are dominant inside stars and liquid planetary cores. This makes more intriguing and surprising the fact that these motions maintain a regular magnetic field. Maintenance of magnetic fields is even more impressive in huge magnets, i.e. galaxies. In fact, we are living inside a giant dynamo machine, the Milky Way galaxy. Although the idea of the global magnetic field of our Galaxy was clearly proposed almost 40 years ago, firm observational evidence and definite theoretical concepts of galactic magnetism have been developed only in the last decade. This book is the first attempt at a full and consistent presentation of this problem. We discuss both theoretical views on the origin of galactic magnetism and the methods of observational study. Previous discussions were on the level of review articles or separate chapters in monographs devoted to cosmic magnetic fields (see, e.g., H. K. Moffatt, 1978, E. N. Parker, 1979 and Zeldovich et aI., 1983).
Download or read book Astronomy and Astrophysics written by and published by . This book was released on 1973 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reprints National Radio Astronomy Observatory Green Bank W Va written by National Radio Astronomy Observatory (U.S.) and published by . This book was released on 1972 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
