Very High Angular Resolution Imaging

Author : J.G. Robertson,W.J. Tango
Publisher : Springer Science & Business Media
Page : 505 pages
File Size : 46,9 Mb
Release : 2013-12-01
Category : Science
ISBN : 9789401108805

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Very High Angular Resolution Imaging by J.G. Robertson,W.J. Tango Pdf

The 1990s are proving to be a very exciting p&iod for high angular resolution astronomy. At radio wavelengths a combination of new array instruments and pow erful imaging algorithms have generated images of unprecedented resolution and quality. In the optical and infrared, the great technical difficulties associated with constructing separated-aperture interferometers have been largely overcome, and many new instruments are now operating or are being developed. As these pro grams start to produce observational results they will be able to draw extensively on the experience gained by the radio-interferometry community. Thus it seemed that the time was ripe for a meeting which would bring together workers from all wavelength ranges to discuss the details of the science and art of "Very High Angular Resolution Imaging" . While the main emphasis of Symposium No. 158 was on high resolution tech niques from the radio, mm-wave, infrared and optical bands, it also provided an opportunity for presentation of astronomical results from these techniques. As well as giving our colleagues from the Northern Hemisphere a break from midwinter, the location of the Symposium in Australia recognised the continuing development of astronomical interferometry in this country, especially the recent completion of the Australia Telescope radio array, and the progress toward com missioning of the Sydney University Stellar Interferometer. A number of the par ticipants visited these instruments during the post-symposium tour.

Author : Henri M. J. Boffin,Gaitee Hussain,Jean-Philippe Berger,Linda Schmidtobreick
Publisher : Springer
Page : 274 pages
File Size : 44,7 Mb
Release : 2016-08-24
Category : Science
ISBN : 9783319397399

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Astronomy at High Angular Resolution by Henri M. J. Boffin,Gaitee Hussain,Jean-Philippe Berger,Linda Schmidtobreick Pdf

This book offers an essential compendium of astronomical high-resolution techniques. Recent years have seen considerable developments in such techniques, which are critical to advances in many areas of astronomy. As reflected in the book, these techniques can be divided into direct methods, interferometry, and reconstruction methods, and can be applied to a huge variety of astrophysical systems, ranging from planets, single stars and binaries to active galactic nuclei, providing angular resolution in the micro- to tens of milliarcsecond scales. Written by experts in their fields, the chapters cover adaptive optics, aperture masking imaging, spectra disentangling, interferometry, lucky imaging, Roche tomography, imaging with interferometry, interferometry of AGN, AGN reverberation mapping, Doppler- and magnetic imaging of stellar surfaces, Doppler tomography, eclipse mapping, Stokes imaging, and stellar tomography. This book is intended to enable a next generation of astronomers to apply high-resolution techniques. It informs readers on how to achieve the best angular resolution in the visible and near-infrared regimes from diffraction-limited to micro-arcsecond scales.

Author : A. Lagrange,Denis Mourard,Pierre Léna
Publisher : Springer Science & Business Media
Page : 404 pages
File Size : 53,8 Mb
Release : 2012-12-06
Category : Science
ISBN : 9789400900417

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High Angular Resolution in Astrophysics by A. Lagrange,Denis Mourard,Pierre Léna Pdf

Over the last decade many efforts have been made to develop high angular resolution techniques in astrophysics. Combined with imaging facilities, they have rapidly proved their efficiency and have already led to major astrophysical results. During the decade to come, astronomers will be offered new, even more sophisticated high angular resolution tools, especially in the IR and optical domains, coupled with much bigger telescopes, either on the ground or in space. In such a context of rapidly evolving techniques and a growing need for higher angular resolution to test theories or discover new objects, the present book reviews both instrumental and scientific aspects. The main questions addressed are: what kind of science will benefit from high angular resolution techniques? How can they best be used? Audience: The book is accessible to students and research workers in both instrumental and astrophysical aspects.

Author : Nicolas Nardetto,Yveline Lebreton,Eric Lagadec
Publisher : EDP Sciences
Page : 158 pages
File Size : 45,8 Mb
Release : 2019-09-26
Category : Science
ISBN : 9782759823734

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Imaging at High Angular Resolution of Stellar Surfaces and Close Environment by Nicolas Nardetto,Yveline Lebreton,Eric Lagadec Pdf

Imaging at high angular resolution (HRA) is a ?ourishing discipline. High performance instruments like the spectro-polarimeter SPHERE at VLT/ESO has recently been implemented. A harvest of splendid results is continuously coming from interferometry with PIONIER, MATISSE, and now GRAVITY (all at VLTI/ESO), VEGA and JouFlu (CHARA), and at longer wavelengths with ALMA at VLTI/ESO and NOEMA/IRAM. The future is already underway with the very close launch of JWST/NASA, and the development of ELT at ESO. HRA provides a unique way to study regions of stellar formation, proto-planetary discs as well as the surfaces of stars and their environments. This volume offers lectures given by world experts in the ?eld during the EvrySchatzman School on Stellar Physics (EES 2017) held in Roscoff, France. The addressed topics include a course of introduction to optical/IR interferometry covering the history and basic principles, a course on diffraction-dominated observational astronomy, and a course presenting the principles and instrumentation of optical long baseline interferometry. This book will be a valuable reference for researchers and students in the coming years.

Author : Dimitris Metaxas,Leon Axel,Gabor Fichtinger,Gabor Szekely
Publisher : Springer
Page : 1111 pages
File Size : 55,8 Mb
Release : 2008-10-30
Category : Computers
ISBN : 9783540859901

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Medical Image Computing and Computer-Assisted Intervention - MICCAI 2008 by Dimitris Metaxas,Leon Axel,Gabor Fichtinger,Gabor Szekely Pdf

The 11th International Conference on Medical Imaging and Computer Assisted Intervention, MICCAI 2008, was held at the Helen and Martin Kimmel Center of New York University, New York City, USA on September 6–10, 2008. MICCAI is the premier international conference in this domain, with - depth papers on the multidisciplinary ?elds of biomedical image computing and analysis, computer assisted intervention and medical robotics. The conference brings together biological scientists, clinicians, computer scientists, engineers, mathematicians, physicists and other interested researchers and o?ers them a forum to exchange ideas in these exciting and rapidly growing ?elds. The conference is both very selective and very attractive: this year we - ceived a record number of 700 submissions from 34 countries and 6 continents, fromwhich258papers were selectedfor publication,whichcorrespondsto a s- cess rate of approximately 36%. Some interesting facts about the distribution of submitted and accepted papers are shown graphically at the end of this preface. The paper selection process this year was based on the following procedure, which included the introduction of several novelties over previous years. 1. A ProgramCommittee (PC) of 49 members was recruited by the Program Chairs,to getthenecessarybody ofexpertiseandgeographicalcoverage.All PC members agreed in advance to participate in the ?nal paper selection process. 2. Key words grouped in 7 categories were used to describe the content of the submissions and the expertise of the reviewers.

Author : D.M. Alloin,Jean-Marie Mariotti
Publisher : Springer Science & Business Media
Page : 444 pages
File Size : 47,7 Mb
Release : 2012-12-06
Category : Science
ISBN : 9789400923409

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Diffraction-Limited Imaging with Very Large Telescopes by D.M. Alloin,Jean-Marie Mariotti Pdf

A few years ago, a real break-through happened in observational astronomy: the un derstanding of the effect of atmospheric turbulence on the structure of stellar images, and of ways to overcome this dramatic degradation. This opened a route to diffraction-limited observations with large telescopes in the optical domain. Soon, the first applications of this new technique led to some outstanding astrophysical results, both at visible and infrared wavelengths. Yet, the potential of interferometric observations is not fully foreseeable as the first long-baseline arrays of large optical telescopes are being built or cOIIllnissioned right now. In this respect a comparison with the evolution of radio-astronomy is tempting. From a situation where, in spite of the construction of giant antennas, low angular resolution was prevailing, the introduction of long baseline and very long baseline interferometry and the rapid mastering of sophisticated image reconstruction techniques, have brought on a nearly routine basis high dynamic range images with milliarcseconds resolution. This, of course, has completely changed our views of the radio sky.

Author : Nicolas Nardetto,Yveline Lebreton,Eric Lagadec
Publisher : Unknown
Page : 156 pages
File Size : 54,6 Mb
Release : 2019
Category : Electronic
ISBN : 2759823725

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Imaging at High Angular Resolution of Stellar Surfaces and Close Environment by Nicolas Nardetto,Yveline Lebreton,Eric Lagadec Pdf

Author : Susumu Mori,J-Donald Tournier
Publisher : Academic Press
Page : 141 pages
File Size : 53,8 Mb
Release : 2013-08-02
Category : Medical
ISBN : 9780123984074

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Introduction to Diffusion Tensor Imaging by Susumu Mori,J-Donald Tournier Pdf

The concepts behind diffusion tensor imaging (DTI) are commonly difficult to grasp, even for magnetic resonance physicists. To make matters worse, a many more complex higher-order methods have been proposed over the last few years to overcome the now well-known deficiencies of DTI. In Introduction to Diffusion Tensor Imaging: And Higher Order Models, these concepts are explained through extensive use of illustrations rather than equations to help readers gain a more intuitive understanding of the inner workings of these techniques. Emphasis is placed on the interpretation of DTI images and tractography results, the design of experiments, and the types of application studies that can be undertaken. Diffusion MRI is a very active field of research, and theories and techniques are constantly evolving. To make sense of this constantly shifting landscape, there is a need for a textbook that explains the concepts behind how these techniques work in a way that is easy and intuitive to understand—Introduction to Diffusion Tensor Imaging fills this gap. Extensive use of illustrations to explain the concepts of diffusion tensor imaging and related methods Easy to understand, even without a background in physics Includes sections on image interpretation, experimental design, and applications Up-to-date information on more recent higher-order models, which are increasingly being used for clinical applications

Author : Joshua Eisner
Publisher : Universal-Publishers
Page : 240 pages
File Size : 43,6 Mb
Release : 2005
Category : Science
ISBN : 9781581122800

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High Angular Resolution Studies of the Structure and Evolution of Protoplanetary Disks by Joshua Eisner Pdf

Young stars are surrounded by massive, rotating disks of dust and gas, which supply a reservoir of material that may be incorporated into planets or accreted onto the central star. In this dissertation, I use high angular resolution observations at a range of wavelengths to understand the structure, ubiquity, and evolutionary timescales of protoplanetary disks. First, I describe a study of Class I protostars, objects believed to be at an evolutionary stage between collapsing spherical clouds and fully-assembled young stars surrounded by protoplanetary disks. I use a Monte Carlo radiative transfer code to model new 0.9 micron scattered light images, 1.3 mm continuum images, and broadband spectral energy distributions. This modeling shows that Class I sources are probably surrounded by massive protoplanetary disks embedded in massive infalling envelopes. For the best-fitting models of the circumstellar dust distributions, I determine several important properties, including envelope and disk masses, mass infall rates, and system inclinations, and I use these results to constrain the evolutionary stage of these objects. Second, I discuss observations of the innermost regions of more evolved disks around T Tauri and Herbig Ae/Be stars, obtained with the Palomar Testbed and Keck Interferometers. I constrain the spatial and temperature structure of the circumstellar material at sub-AU radii, and demonstrate that lower-mass stars are surrounded by inclined disks with puffed-up inner edges 0.1-1 AU from the star. In contrast, the truncated inner disks around more massive stars may not puff-up, indicating that disk structure depends on stellar properties. I discuss the implications of these results for disk accretion, terrestrial planet formation and giant planet migration. Finally, I put these detailed studies of disk structure into a broader context by constraining the mass distribution and evolutionary timescales of circumstellar disks. Using the Owens Valley Millimeter Array, I mapped the millimeter continuum emission toward >300 low-mass stars in the NGC 2024 and Orion Nebula clusters. These observations demonstrate that the average disk mass in each cluster is comparable to the "minimum-mass protosolar nebula," and that there may be disk evolution on one million year timescales.

Author : Anonim
Publisher : Unknown
Page : 490 pages
File Size : 54,7 Mb
Release : 1990
Category : Astronautics
ISBN : UOM:39015023291621

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NASA Reference Publication by Anonim Pdf

Author : T. Kogure,A.T. Tokunaga
Publisher : Springer Science & Business Media
Page : 392 pages
File Size : 45,5 Mb
Release : 2013-06-29
Category : Science
ISBN : 9789401720038

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Japanese National Large Telescope and Related Engineering Developments by T. Kogure,A.T. Tokunaga Pdf

Proceedings of the International Symposium on Large Telescopes, held in Tokyo, Japan, November 29-December 2, 1988

Author : H.M.J. Boffin,D. Steeghs,J. Cuypers
Publisher : Springer
Page : 434 pages
File Size : 48,7 Mb
Release : 2008-01-11
Category : Science
ISBN : 9783540453390

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Astrotomography by H.M.J. Boffin,D. Steeghs,J. Cuypers Pdf

This comprehensive and unique reference work on astro-tomography is based on expanded and suitably edited contributions to the 1st International Workshop on Astro-tomography. The focus is on studying indirect imaging and subsequent reconstruction techniques with applications in all areas of observational astronomy, astrophysics and cosmology. Detailed subject and object indexes, together with a list of useful resources on the Internet, will help the reader to use this book in a most efficient way.

Author : Anonim
Publisher : Unknown
Page : 824 pages
File Size : 42,9 Mb
Release : 1977
Category : Astronautics
ISBN : MINN:31951P00141907T

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NASA Reference Publication by Anonim Pdf

Author : Derek McNally
Publisher : Springer Science & Business Media
Page : 663 pages
File Size : 45,9 Mb
Release : 2012-12-06
Category : Science
ISBN : 9789400909779

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Highlights of Astronomy by Derek McNally Pdf

It is the customary practice to report the major events of a General Assembly -the Invited Discourses, Joint Discussions and Joint Commission Meetings in Highlights of Astronomy. Vol. 8 reports the highlights of the XXth General Assembly of the International Astronomical Union, 1988 August 2-11, Baltimore, USA. The present volume contains the 3 Invited Discourses and papers presented at 7 Joint Discussion Meetings and 6 Joint Commission Meetings. Two Joint Commission Meetings will be reported elsewhere -JCM5 Spectroscopy of Individual Stars in Globular Clusters and the Early Chemical Evolution of our Galaxy (in summary only here, published by the Imprimerie de l'Observatoire de Paris) and JCM7 Star Clusters in the Magellanic Clouds (see Transactions of the IAU, Vol.XXB, report of Commission 37). I am most grateful to the authors of the invited discourses R.M. West and V.I. Moroz, M. Schmidt and M. Rees for sending me the manuscripts so promptly. I am also indebted to the Chairmen of the Joint Discussion and Joint Commission Meetings for their organisation of the meetings and for the assembly of their material for publication. Unfortunately the deadline for receipt of manuscripts coincided with an extended postal strike in France which seriously hindered the preparation of the volume for publication.

Author : Alvaro Gimenez,Edward Guinan,Panagiotis Niarchos,Slavek Rucinski
Publisher : Springer Science & Business Media
Page : 349 pages
File Size : 45,7 Mb
Release : 2007-04-05
Category : Science
ISBN : 9781402050275

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Close Binaries in the 21st Century: New Opportunities and Challenges by Alvaro Gimenez,Edward Guinan,Panagiotis Niarchos,Slavek Rucinski Pdf

This book is the proceedings of an international conference entitled "Close Binaries in the 21st Century: New Opportunities and Challenges", held in Syros island, Greece, June 27-30, 2005. The papers collected in this volume detail the latest achievements in the field and reflect the state of the art of the dynamically evolving area of binary star research.