Download or read book Analyse optique tr s haute r solution spectrale de la galaxie NGC 1275 written by Benjamin Vigneron and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les galaxies centrales d'amas de galaxies constituent un environnement particulier pouvant parfois être entouré, dans le domaine optique, d'un système filamentaire complexe et étendu. L'étude de ces structures permet de mieux comprendre le phénomène de rétroaction impliqué au sein de ces galaxies et lié à la présence d'un trou noir supermassif en leur centre. La formation de jets et de bulles remplis d'émission radio conduit à réchauffer et sculpter le milieu intra-amas environnant. Ce réchauffement empêche ainsi le refroidissement du gaz intra-amas et donc la formation stellaire. Les filaments visibles dans le domaine optique ne constituent qu'une partie de la structure multiphasique qui entoure la galaxie centrale d'amas. En effet, plusieurs observations en rayons X du gaz intra-amas et radio du gaz moléculaire montrent clairement des corrélations spatiales entre toutes ces types d'émissions. Néanmoins, plusieurs points restent encore incertains concernant ces nébuleuses filamentaires. Deux modèles principaux s'opposent ainsi pour tenter d'expliquer l'origine de leur formation et le phénomène d'ionisation du gaz n'est toujours pas déterminé avec certitude. Dès lors, l'étude de la nébuleuse filamentaire entourant la galaxie centrale de l'amas de Persée, NGC 1275, au moyen d'observations à très haute résolution spectrale à l'aide de l'instrument SITELLE (Spectromètre imageur à transformée de Fourier pour l'étude en long et en large de raies d'émission), se révèle fondamentale. Ce spectromètre imageur à transformée de Fourier installé au télescope Canada-France-Hawaï dispose de caractéristiques exceptionnelles nous permettant d'étudier la nébuleuse filamentaire de NGC 1275 dans son entièreté. En effet, le champ de vue extrêmement large de SITELLE ($11' \times 11'$) ainsi que sa capacité d'atteindre de très hautes résolutions spectrales en font un atout de choix pour l'étude de telle structure. Dans ce mémoire, nous avons analysé de nouvelles observations de NGC 1275 obtenues avec SITELLE, à une très haute résolution spectrale de $R = \lambda/\Delta\lambda = 7000$. L'analyse de ces observations a permis de renouveler les cartes de vitesse, flux et dispersion en vitesse au sein de la nébuleuse filamentaire, démontrant ainsi que la région centrale semble plus dynamique qu'anticipée auparavant. De plus, grâce à la très haute résolution spectrale atteinte au sein de ces données, une analyse détaillée des raies d'émission de [SII] a pu être menée, révélant dès lors plus d'informations sur la densité du gaz au sein des filaments. L'étude de ratio de raies permet également de mieux cerner le mécanisme d'ionisation ayant lieu au sein de cette structure. Finalement, cette étude de données à très haute résolution spectrale des filaments permettra à terme d'obtenir les diagrammes BPT offrant ainsi une meilleure compréhension du phénomène d'ionisation. Une étude sera également menée sur les multiples composantes en vitesse visible localement dans la région centrale des filaments et pouvant être résolues. Enfin, ces données serviront de base pour les futures observations en rayon X de l'instrument XRISM (\textit{X-Ray Imaging and Spectroscopy Mission}).
Download or read book Active Galactic Nuclei written by R.D. Blandford and published by Springer Science & Business Media. This book was released on 2006-04-18 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Swiss Society for Astrophysics and Astronomy organizes each year in the late winter or early spring an advanced course. The format of the school is always iden tical: three leading lecturers are invited to cover the subject in nine or ten lectures each and to deliver a written version of their lecture notes. Lectures are held in the morning and late afternoon, thus leaving ample time for discussion and skiing. These arrangements prove very convivial and lead to an excellent atmosphere in which to learn exciting new subjects and establish contacts with colleagues. A wide variety of people attend the school, including many young students, mostly from Europe, and some experienced researchers. The 20th Advanced Course of the Swiss Society for Astrophysics and Astronomy took place in Les Diablerets from 1 to 6 April 1990. It was devoted to observational and theoretical aspects of active galactic nuclei. The previous advanced courses of the Swiss Society for Astrophysics and Astronomy have regularly taken place in Saas-Fee, a small resort in the Swiss Alps, hence the name "Saas-Fee" used to de scribe the courses and lecture notes. In the last three years, however, the course was organized in Leysin and in Les Diablerets, both also situated in the Swiss Alps.
Download or read book Observational Astrophysics written by Pierre Lena and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the last twenty years astronomy has been developing dramatically. Until the nineteen-fifties, telescopes, spectrometers, and photographic plates consti tuted a relatively simple set of tools which had been refined to a high degree of perfection by the joint efforts of physicists and astronomers. Indeed these tools helped at the birth of modern astrophysics: the discovery of the expan sion of the Universe. Then came radioastronomy and the advent of electronics; the last thirty years have seen the application to astrophysics of a wealth of new experimental techniques, based on the most advanced fields of physics, and a constant interchange of ideas between physicists and astronomers. Last, but not least, modern computers have sharply reduced the burden of dealing with the information painfully extracted from the skies, whether from ever scarce photons, or from the gigantic data flows provided by satellites and large telescopes. The aim of this book is not to give an extensive overview of all the tech niques currently in use in astronomy, nor to provide detailed instructions for preparing or carrying out an astronomical project. Its purpose is methodologi cal: photons are still the main carriers of information between celestial sources and the observer. How we are to collect, sample, measure, and store this infor mation is the unifying theme of the book. Rather than the diversity of tech niques appropriate for each wavelength range, we emphasize the physical and mathematical bases which are common to all wavelength regimes.
Download or read book Fifty Years of Quasars written by Mauro D'Onofrio and published by Springer. This book was released on 2014-10-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 50th anniversary of the discovery of quasars in 1963 presents an interesting opportunity to ask questions about the current state of quasar research. Formatted as a series of interviews with noted researchers in the field, each of them asked to address a specific set of questions covering topics selected by the editors, this book deals with the historical development of quasar research and discusses how advances in instrumentation and computational capabilities have benefitted quasar astronomy and have changed our basic understanding of quasars. In the last part of the book the interviews address the current topic of the role of quasars in galaxy evolution. They summarise open issues in understanding active galactic nuclei and quasars and present an outlook regarding what future observational facilities both on the ground and in space might reveal. Its interview format, the fascinating topic of quasars and black holes, and the lively recollections and at times controversial views of the contributors make this book both rewarding and a pleasure to read!
Download or read book Starbursts and Galaxy Evolution written by Xuan Thuan Trinh and published by Atlantica Séguier Frontières. This book was released on 1987 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamical Evolution of Star Clusters Confrontation of Theory and Observations written by Piet Hut and published by Springer. This book was released on 1996-06-30 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews recent progress in the study of dynamics of star clusters. The meeting focused on the enormous progress of both the observation and the theoretical modeling of star clusters. New results from the refurbished Hubble Space Telescope (HST) include the mass function down to the hydrogen burning limits, white dwarf sequence, and central density profiles of `post-collapse' clusters by star counts. On the theoretical side, this symposium saw the first direct evidence of gravothermal oscillation through N-body simulation, which was made possible by GRAPE-4, the dedicated special-purpose computer for N-body simulation. Numerical techniques to combine stellar evolution and dynamical evolution of the cluster were presented. The book will be of primary interest to astrophysicists.
Download or read book The Physics of the Early Universe written by Eleftherios Papantonopoulos and published by Springer Science & Business Media. This book was released on 2005-01-07 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Physics of the Early Universe is an edited and expanded version of the lectures given at a recent summer school of the same name. Its aim is to present an advanced multi-authored textbook that meets the needs of both postgraduate students and young researchers interested in, or already working on, problems in cosmology and general relativity, with emphasis on the early universe. A particularly strong feature of the present work is the constructive-critical approach to the present mainstream theories, the careful assessment of some alternative approaches, and the overall balance between theoretical and observational considerations. As such, this book will also benefit experienced scientists and nonspecialists from related areas of research.
Download or read book The Nearest Active Galaxies written by J. E. Beckman and published by Editorial CSIC - CSIC Press. This book was released on 1993 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exoplanets written by John Mason and published by Springer Science & Business Media. This book was released on 2008-08-29 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first collection of review articles in one volume covering the very latest developments in exoplanet research. This edited, multi-author volume will be an invaluable introduction and reference to all key aspects in the field this field. The reviews cover topics such as the properties of known exoplanets and searching for exoplanets in the stellar graveyard. The book provides an easily accessible point of reference in a fast moving and exciting field.
Download or read book The X ray Background written by Xavier Barcons and published by Cambridge University Press. This book was released on 1992-07-31 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the current observational knowledge and understanding of the cosmic X-ray background.
Download or read book Cosmic Discovery written by Martin Harwit and published by Cambridge University Press. This book was released on 2019-03-21 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: The search -- Discoveries -- Observation -- Detection, recognition, and classification of cosmic phenomena -- The fringes of legitimacy : the need for enlightened planning.
Download or read book Lecture Notes on Introductory Theoretical Astrophysics written by R. J. Weymann and published by . This book was released on 1976 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hearings Reports and Prints of the Senate Select Committee on Small Business written by United States. Congress. Senate. Select Committee on Small Business and published by . This book was released on 1980 with total page 1104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heredity and the Aetiology of the Neuroses written by Sigmund Freud and published by Read Books Ltd. This book was released on 2014-11-11 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: This early work by Sigmund Freud was originally published in 1896 and we are now republishing it with a brand new introductory biography. 'Heredity and the Aetiology of the Neuroses' is a psychological essay on the causes of neuroses. Sigismund Schlomo Freud was born on 6th May 1856, in the Moravian town of Príbor, now part of the Czech Republic. He studied a variety of subjects, including philosophy, physiology, and zoology, graduating with an MD in 1881. Freud made a huge and lasting contribution to the field of psychology with many of his methods still being used in modern psychoanalysis. He inspired much discussion on the wealth of theories he produced and the reactions to his works began a century of great psychological investigation.
Download or read book Heart life in Song written by Frances Harrison Marr and published by . This book was released on 1883 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fresh from the Farm 6pk written by Rigby and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book History of the IAU written by Adriaan Blaauw and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: This History has its origin in a suggestion, made in September 1990 by former IAU General Secretary Derek McNally, who felt "that a 75 year history of the Union was needed before the col lective memory of those who knew the Union before the Second World War vanished. It would then be a preparatory volume to a centennial history in 2019. " Indeed, of those who knew the Union that long ago, few are still with us. Six years ago, at Baltimore on August 2, 1988, listening and reminiscing at the Inaugural Ceremonies of the Union's 20th General Assembly, I realized that it was almost exactly half a century ago that, at the age of 24, I attended the Inaugurations at my "first" Assembly: on August 3, 1938 in Stockholm. Now, in 1994, this is almost 56 years ago, three quarters of the Union's age. Only vague recollections - no better than that -lead me back to this event, just before World War II. And so, this is not a history based on recollection, far from it. Recollection was helpful in that it allowed me, better perhaps than a younger author, to appreciate circumstances under which the letters and reports which form the basis for this History were written. The account is largely based on archival documents, collected from a wide variety of sources.
