Download or read book Aperture Synthesis of Neutral Hydrogen in the Galaxy M33 written by David H. Rogstad and published by . This book was released on 1975 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations of the neutral hydrogen in the galaxy M33 with resolutions of 2' and 10 km/s are described. Detailed modeling has revealed weak evidence for spiral density waves with an arm-interarm contrast of 3 to 2 and a corotation radius in the range 7' to 12'. There is substantial evidence for large-scale warping of the plane of this galaxy in its outer extremities similar to that found in M83.
Download or read book Aperture Synthesis Observations of Neutral Hydrogen in Three Galaxies written by G. Seth Shostak and published by . This book was released on 1974 with total page 228 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 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 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 of Interstellar Neutral Hydrogen in Absorption written by Eric Winslow Greisen and published by . This book was released on 1973 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 of Interstellar Neutral Hydrogen in Absorption II Cygnus A the Crab Nebula and Other Sources written by Eric W. Greisen and published by . This book was released on 1973 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Owens Valley Radio Observatory interferometer has been used to carry out a program of aperture synthesis in the interstellar neutral hydrogen line. The results of synthesis observations of Cygnus A, the Crab Nebula and 3C353 and single-spacing observations of W12 and 3C147 are presented. Considerable spatial structure in the absorbing medium is found with scale lengths about 1 pc (and perhaps even as small as 0.14 pc) being common. Some of the small-scale features are seen as condensations within much larger clouds. The hydrogen densities appear to be mostly on the order of 100/cc. Upper limits to the temperatures lower than 50K are found for some spectral components, but upper limits between 80 and 160K are more common. The implications of these results for the two-phase model of the interstellar medium are discussed. (Author Modified Abstract).
Download or read book Aperture Synthesis Observations of HI in the Galaxy M83 written by D. H. Rogstad and published by . This book was released on 1974 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: High resolution observations of neutral hydrogen in the spiral galaxy M83 reveal a very extended HI distribution and a peculiar velocity field. An interpretation is presented in terms of substantial warping of the plane of the galaxy for the material outside the optical image. The time scale for persistence of this bending is estimated to be longer than two billion years. (AuthoR).
Download or read book The New Astronomy Opening the Electromagnetic Window and Expanding our View of Planet Earth written by Wayne Orchiston and published by Springer Science & Business Media. This book was released on 2005-10-18 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an unusual book, combining as it does papers on astrobiology, history of astronomy and sundials, but—after all—Woody Sullivan is an unusual man. In late 2003 I spent two fruitful and enjoyable months in the Astronomy Department at the University of Washington (UW) working on archival material accumulated over the decades by Woody, for a book we will co-author with Jessica Chapman on the early development of Australian astronomy. The only serious intellectual distraction I faced during this period was planning for an IAU colloquium on transits of Venus scheduled for June 2004 in England, where I was down to present the ‘Cook’ paper. I knew Woody was also interested in transits (and, indeed, anything remotely connected with shadows—see his paper on page 3), and in discussing the Preston meeting with him it transpired that his 60th birthday was timed to occur just one week later. This was where the seed of ‘Woodfest’ began to germinate. Why not invite friends and colleagues to join Woody in Seattle and celebrate this proud event? I put the idea to Woody and others at UW, they liked it, and ‘Woodfest’ was born.
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 756 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 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973 with total page 1734 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vera Rubin written by Jacqueline Mitton and published by Harvard University Press. This book was released on 2021-02-11 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first biography of a pioneering scientist who made significant contributions to our understanding of dark matter and championed the advancement of women in science. One of the great lingering mysteries of the universe is dark matter. Scientists are not sure what it is, but most believe it’s out there, and in abundance. The astronomer who finally convinced many of them was Vera Rubin. When Rubin died in 2016, she was regarded as one of the most influential astronomers of her era. Her research on the rotation of spiral galaxies was groundbreaking, and her observations contributed significantly to the confirmation of dark matter, a most notable achievement. In Vera Rubin: A Life, prolific science writers Jacqueline Mitton and Simon Mitton provide a detailed, accessible overview of Rubin’s work, showing how she leveraged immense curiosity, profound intelligence, and novel technologies to help transform our understanding of the cosmos. But Rubin’s impact was not limited to her contributions to scientific knowledge. She also helped to transform scientific practice by promoting the careers of women researchers. Not content to be an inspiration, Rubin was a mentor and a champion. She advocated for hiring women faculty, inviting women speakers to major conferences, and honoring women with awards that were historically the exclusive province of men. Rubin’s papers and correspondence yield vivid insights into her life and work, as she faced down gender discrimination and met the demands of family and research throughout a long and influential career. Deftly written, with both scientific experts and general readers in mind, Vera Rubin is a portrait of a woman with insatiable curiosity about the universe who never stopped asking questions and encouraging other women to do the same.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1993 with total page 1146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Formation and Dynamics of Galaxies written by J.R. Shakeshaft and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of IAU Symposium No. 58 held in Canberra, Australia, August 12-15, 1973
Download or read book ERDA Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
