Download or read book FORMATION ET EVOLUTION DES STRUCTURES DANS LE MILIEU INTERSTELLAIRE UNE APPROCHE THEORIQUE NUMERIQUE ET OBSERVATIONNELLE written by PATRICK.. HENNEBELLE and published by . This book was released on 2000 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: LE MILIEU INTERSTELLAIRE, AU SEIN DUQUEL SE FORME LES ETOILES, PRESENTE D'IMPORTANTS CONTRASTES DE DENSITES. CES STRUCTURES SE FORMENT SOUS L'ACTION COUPLEE DE PROCESSUS MAGNETOHYDRODYNAMIQUES, THERMIQUES ET CHIMIQUES. LA PREMIERE PARTIE DE CETTE THESE EST UN TRAVAIL THEORIQUE ET NUMERIQUE SUR LA CONDENSATION INDUITE DYNAMIQUEMENT DE GAZ CHAUD ET DIFFUS EN UNE PHASE FROIDE ET CONDENSEE. NOUS MONTRONS, TOUT D'ABORD DANS LE CAS HYDRODYNAMIQUE, PUIS MHD, COMMENT, DANS UN MILIEU THERMIQUEMENT BISTABLE, UNE FLUCTUATION DE VITESSE TYPIQUEMENT TRANSONIQUE CONDUIT, SI ELLE EST D'AMPLITUDE SUFFISANTE ET DURE UN TEMPS ASSEZ LONG, A LA FORMATION D'UNE STRUCTURE STABLE. L'INFLUENCE DE DIVERS PARAMETRES -AMPLITUDE ET ECHELLE SPATIALE CARACTERISTIQUE DE LA PERTURBATION, PRESSION INITIALE, CONFIGURATION DU CHAMP MAGNETIQUE- SUR LA CONDENSATION EST ETUDIEE NUMERIQUEMENT ET ANALYTIQUEMENT. DES SPECTRES SYNTHETIQUES SONT CALCULES ET QUALITATIVEMENT COMPARES AUX SPECTRES OBSERVATIONNELS. LA SECONDE PARTIE DE LA THESE PORTE SUR L'ETUDE OBSERVATIONNELLE DES PHASES LES PLUS CONDENSEES DU MILIEU INTERSTELLAIRE DETECTEES EN ABSORPTION SUR LE FOND INFRAROUGE GALACTIQUE PAR LE SATELLITE ISO. NOUS EFFECTUONS TOUT D'ABORD UNE EXTRACTION SYSTEMATIQUE DE CES OBJETS A PARTIR D'UNE ANALYSE MULTI-ECHELLE DES DONNEES ISOGAL. L'ETUDE DU RAPPORT DES CONTRASTES A 7 ET 15M PERMET DE MESURER LE RAPPORT DE L'EXTINCTION INTERSTELLAIRE, PEU CONNUE DANS CETTE REGION DU SPECTRE, A CES DEUX LONGUEURS D'ONDE. DES ESTIMATIONS D'OPACITE DE QUELQUES OBJETS SONT EGALEMENT DEDUITES DES DONNEES EN INFRAROUGE. DES OBSERVATIONS COMPLEMENTAIRES SPECTROSCOPIQUES ET BOLOMETRIQUES DANS LE DOMAINE RADIO ONT ETE EFFECTUEES ET PERMETTENT UNE ANALYSE PLUS DETAILLEE DES PARAMETRES PHYSICO-CHIMIQUES DE CES NUAGES.
Download or read book Formation et volution des structures dans le milieu interstellaire une approche th orique num rique et observationnelle written by Patrick Hennebelle and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le milieu interstellaire, au sein duquel se forment les étoiles, présente d'importants contrastes de densités. Ces structures se forment sous l'action couplée de processus magnétohydrodynamiques, thermiques et chimiques. La première partie de cette thèse est un travail théorique et numérique sur la condensation induite dynamiquement de gaz chaud et diffus en une phase froide et condensée. Nous montrons, tout d'abord dans le cas hydrodynamique, puis MHD, comment, dans un milieu thermiquement bistable, une fluctuation de vitesse typiquement transonique conduit, si elle est d'amplitude suffisante et dure un temps assez long, à la formation d'une structure stable. L'influence de divers paramètres -amplitude et échelle spatiale caractéristique de la perturbation, pression initiale, configuration du champ magnétique- sur la condensation est étudiée numériquement et analytiquement. Des spectres synthétiques sont calcules et qualitativement compares aux spectres observationnels. La seconde partie de la thèse porte sur l'étude observationnelle des phases les plus condensées du milieu interstellaire détectées en absorption sur le fond infrarouge galactique par le satellite iso. Nous effectuons tout d'abord une extraction systématique de ces objets à partir d'une analyse multi-échelle des données isogal. L'étude du rapport des contrastes à 7 et 15m permet de mesurer le rapport de l'extinction interstellaire, peu connue dans cette région du spectre, a ces deux longueurs d'onde. Des estimations d'opacité de quelques objets sont également déduites des données en infrarouge. Des observations complémentaires spectroscopiques et bolométriques dans le domaine radio ont été effectuées et permettent une analyse plus détaillée des paramètres physico-chimiques de ces nuages.
Download or read book Quantum Mechanics Volume 3 written by Claude Cohen-Tannoudji and published by John Wiley & Sons. This book was released on 2019-12-16 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new, third volume of Cohen-Tannoudji's groundbreaking textbook covers advanced topics of quantum mechanics such as uncorrelated and correlated identical particles, the quantum theory of the electromagnetic field, absorption, emission and scattering of photons by atoms, and quantum entanglement. Written in a didactically unrivalled manner, the textbook explains the fundamental concepts in seven chapters which are elaborated in accompanying complements that provide more detailed discussions, examples and applications. * Completing the success story: the third and final volume of the quantum mechanics textbook written by 1997 Nobel laureate Claude Cohen-Tannoudji and his colleagues Bernard Diu and Franck Laloë * As easily comprehensible as possible: all steps of the physical background and its mathematical representation are spelled out explicitly * Comprehensive: in addition to the fundamentals themselves, the books comes with a wealth of elaborately explained examples and applications Claude Cohen-Tannoudji was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris where he also studied and received his PhD in 1962. In 1973 he became Professor of atomic and molecular physics at the Collège des France. His main research interests were optical pumping, quantum optics and atom-photon interactions. In 1997, Claude Cohen-Tannoudji, together with Steven Chu and William D. Phillips, was awarded the Nobel Prize in Physics for his research on laser cooling and trapping of neutral atoms. Bernard Diu was Professor at the Denis Diderot University (Paris VII). He was engaged in research at the Laboratory of Theoretical Physics and High Energy where his focus was on strong interactions physics and statistical mechanics. Franck Laloë was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris. His first assignment was with the University of Paris VI before he was appointed to the CNRS, the French National Research Center. His research was focused on optical pumping, statistical mechanics of quantum gases, musical acoustics and the foundations of quantum mechanics.
Download or read book The X ray Universe written by Wallace H. Tucker and published by . This book was released on 1985 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beyond the range of optical perception--and of ordinary imaginings--a new and violent universe lay undetected until the advent of space exploration. Supernovae, black holes, quasars and pulsars--these were the secrets of the highenergy world revealed when, for the first time, astronomers attached their instruments to rockets and lofted them beyond the earth's x-ray-absorbing atmosphere. The X-Ray Universe is the story of these explorations and the fantastic new science they brought into being. It is a first-hand account: Riccardo Giacconi is one of the principal pioneers of the field, and Wallace Tucker is a theorist who worked closely with him at many critical periods. The book carries the reader from the early days of the Naval Research Laboratory through the era of V-2 rocketry, Sputnik, and the birth of NASA, to the launching of the Einstein X-Ray Observatory. But this is by no means just a history. Behind the suspenseful, sometimes humorous details of human personality grappling with high technology lies a sophisticated exposition of current cosmology and astrophysics, from the rise and fall of the steady-state theory to the search for the missing mass of the universe.
Download or read book A New Astronomy written by David Peck Todd and published by . This book was released on 1906 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods of Detecting Exoplanets written by Valerio Bozza and published by Springer. This book was released on 2016-04-12 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, renowned scientists describe the various techniques used to detect and characterize extrasolar planets, or exoplanets, with a view to unveiling the “tricks of the trade” of planet detection to a wider community. The radial velocity method, transit method, microlensing method, and direct imaging method are all clearly explained, drawing attention to their advantages and limitations and highlighting the complementary roles that they can play in improving the characterization of exoplanets’ physical and orbital properties. By probing the planetary frequency at different distances and in different conditions, these techniques are helping astrophysicists to reconstruct the scenarios of planetary formation and to give robust scientific answers to questions regarding the frequency of potentially habitable worlds. Twenty years have passed since the discovery of a Jupiter-mass companion to a main sequence star other than the Sun, heralding the birth of extrasolar planetary research; this book fully conveys the exciting progress that has been achieved during the intervening period.
Download or read book Landmarks in Developmental Biology 1883 1924 written by Klaus Sander and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developmental biology took shape between 1880 and the 1920s Basic concepts like the developmental role of chromosomes and the germ plasm (today's genome), self differentiation, embryonic regulation and induction, gradients and organizers hail from that period; indeed, the discipline was defined as a whole by the programmatic writings of Wilhelm Roux as early as 1889. The present essays cover the period up to the Nobel prize-winning work of Hans Spemann and Hilde Mangold. They were originally published in Roux's Archives of Developmental Biology, from Vol. 200 onward to the journal's centennial issues in 1995/96. The essays aim at introducing current adepts of developmental biology to observations and experiments that have lead their predecessors towards basic concepts still influential today.
Download or read book A Treatise on Astronomy written by John Frederick William Herschel and published by . This book was released on 1834 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Astronomical Revolution written by Alexandre Koyre and published by Routledge. This book was released on 2013-04-15 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published in English in 1973. This volume traces the development of the revolution which so drastically altered man’s view of the universe in the sixteenth and seventeenth centuries. The "astronomical revolution" was accomplished in three stages, each linked with the work of one man. With Copernicus, the sun became the centre of the universe. With Kepler, celestial dynamics replaced the kinematics of circles and spheres used by Copernicus. With Borelli the unification of celestial and terrestrial physics was completed by abandonment of the circle in favour the straight line to infinity.
Download or read book Uranometria Nova written by Friedrich Argelander and published by Wentworth Press. This book was released on 2019-02-20 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book Popular Astronomy written by François Arago and published by . This book was released on 1858 with total page 916 pages. Available in PDF, EPUB and Kindle. Book excerpt:
