[PDF] Structure In The Interstellar Extinction Curve eBook

Author : J. Mayo Greenberg
Publisher : Springer Science & Business Media
Page : 538 pages
File Size : 46,43 MB
Release : 2013-04-17
Category : Science
ISBN : 9401026645

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IAU Symposium Number 52 on Interstellar Dust and Related Topics was held at Albany, N.Y., on the campus of the State University of New York at Albany from May 29 to June 2, 1972. The members of the Organizing Committee were: Dr A. D. Code, University of Wisconsin, Madison, Wis., U.S.A. Dr B. D. Donn, Goddard Space Flight Center, Greenbelt, Md., U.S.A. Dr A. Elvius, Stockholm Observatory, Saltsjobaden, Sweden. Dr T. Gehrels, Lunar and Planetary Laboratory, University of Arizona, Tucson, Ariz., U.S.A. Dr J. M. Greenberg (Chairman), State University of New York at Albany, Albany, N.Y., U.S.A. Dr H. C. van de Hulst, Sterrewacht, Leiden, Holland. Dr S. B. Pikel'ner, Sternberg Astronomical Institute, Moscow, U.S.S.R. Dr E. E. Salpeter, Cornell University, Ithaca, N.Y., U.S.A. Dr B. E. Turner, National Radio Astronomy Observatory, Charlottesville, Va., U.S.A. The suggestion was first made in 1971 that a symposium on interstellar grains would be timely. The response to the first preliminary announcement, which was sent out on November 29, 1971, was well beyond our expectations. The meeting was locally sponsored by the State University and by Dudley Observatory. The National Aeronautics and Space Administration and the National Science Foundation con tributed along with the IAU. There were 158 participants of whom 49 were from 15 countries outside the United States. A total of 92 papers were presented.

Author : Thomas Henning
Publisher : Springer Science & Business Media
Page : 265 pages
File Size : 39,55 MB
Release : 2012-12-06
Category : Science
ISBN : 9400937857

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TH. HENNING and B. STECKLUM University Observatory. Jena This workshop was organized by the University Observatory Jena and devoted to the physics and chemistry of dense regions of interstellar matter. It was especially dealing with the properties of interstellar dust grains and star formation in those regions. This field of research was opened in Jena already in the 1950s and an early fA U Colloquium on the topic of interstellar matter was held here in 1969. Since that time, the subject of interstellar matter has grown into a much more important part of astrophysics than it was in 1969. Now we are beginning to understand the process of star formation in a greater detail. The discovery of many interstellar molecules by radioastronomers opened the new field of interstellar chemistry. In addition, the application of the new techniques of infrared astronomy led to the discovery of several absorption bands, e. g. , the 3. 1 11m ice band, which pointed to the existence of grain mantles. More recently, the detection of infrared emission lines was the first hint to the existence of a new component of interstellar matter. All these things were discussed extensively during the workshop. The very successful IRAS mission, which was also a subject of this workshop, gave us many new insights and unexpected findings, e. g. , the detection of infrared cirrus clouds.

Author : D.C.B Whittet
Publisher : CRC Press
Page : 405 pages
File Size : 44,22 MB
Release : 2018-10-08
Category : Science
ISBN : 1482268647

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Dust is a ubiquitous feature of the cosmos, impinging directly or indirectly on most fields of modern astronomy and astrophysics. Dust in the Galactic Environment, Second Edition provides a thorough overview of the subject, covering general concepts, methods of investigation, important results and their significance, relevant literature, and some suggestions for promising avenues of future research. Since the publication of the first edition of this popular graduate text, major advances have been made in our understanding of astrophysical dust, especially in the light of exciting new results from space- and ground-based telescopes, together with advances in laboratory astrophysics and theoretical modeling. This new, expanded edition highlights the latest results and provides a context for future research opportunities. The first chapter provides a historical perspective for current research and an overview of interstellar environments and the role of dust in astrophysical processes, followed by a discussion of the cosmic history of the chemical elements expected to be present in dust and an examination of the effect of gas-dust interactions on gas phase abundances. The next several chapters describe the observed properties of interstellar grains, such as their extinction, polarization, absorption, and emission characteristics. Then, the book explores the origin and evolution of dust, tracing its life cycle in a succession of environments from circumstellar shells to diffuse interstellar clouds, molecular clouds, protostars, and protoplanetary disks. The final chapter summarizes progress toward a unified model. Dust in other galaxies is discussed as an integral part of the text rather than as a distinct topic requiring separate chapters. Containing extensive references and problems to aid understanding and illustrate basic principles, the book is ideally suited for graduate and advanced undergraduate courses. It will also be an invaluable reference for postgraduate students and researchers working in this important field.

Author : Petia Yanchulova
Publisher :
Page : 126 pages
File Size : 15,17 MB
Release : 2020
Category :
ISBN :

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Interstellar dust is a ubiquitous component of galaxies, but some of its most fundamental properties are still poorly understood. This work analyzes the average extinction properties of dust in the Small Magellanic Cloud (SMC) through color-magnitude diagrams (CMDs) of resolved stars observed with the Hubble Space Telescope (HST). It also investigates the three-dimensional structure of the SMC, since the galaxy's proximity and dynamic interaction history provide a unique way to simultaneously study both dust extinction and galactic geometry. The observations are taken as part of the Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE) program examining a 200 x 100 parsec region in the SW bar of the SMC. SMC-like dust extinction is frequently used to correct observations of high-redshift or low-metallicity galaxies due to SMC's own low metallicity. The dust extinction law or curve describing the stellar extinction in magnitudes as a function wavelength is the quantity used for this purpose. Fundamentally, the extinction law holds information about the dust grain size and composition. The SMIDGE survey has made it possible to find the average dust extinction properties in the SMC and build upon the handful of measurements in existence prior to the survey. Chapter 1 is an introduction to the importance of SMC dust extinction curve and galactic geometry measurements, and to the approach taken here to answer questions about these two measurements. Chapter 2 explores the average SMC dust extinction curve through multiband HST photometric observations of evolved red clump stars. The study focuses on the measurement of the slope of the red clump reddening vector from the CMD relying on a simple model which takes into account the extinction curve shape, a log-normal distribution of extinctions, and the distance distribution of the stellar component along the line of sight. The results for the shape of the average SMC extinction curve are consistent with prior measurements, and also point to a significant galactic depth along the line-of-sight, in line with recent studies. Chapter 3describes work on a more complex model for the SMC, using red clump and red giant branch stars on a CMD. The model simulates the dust-stars offset and the stellar distance distribution, yielding the reddened fraction of stars. It also simulates a dust layer with a log-normal extinction distribution $A_V$ - the extinction in magnitudes in the optical $V$ photometric band--with width [sigma]_{A_V}$. This work results in the first detailed dust extinction and 3D geometry properties in a key region in the SMC. It also produces a photometry-based $A_V$ result allowing for a measurement of the dust mass content of the galaxy which is independent from infrared dust emission observations. This is one of a few measurements of $A_V$ at low metallicity which can be compared to gas and dust content measured from infrared emission. Similarly to other photometry-based extinction results in Andromeda and the Milky Way, it points to a potential overestimation of the dust mass derived from dust grain models relying on IR dust emission data. Chapter 4 summarizes this dissertation and describes future work on SMC's dust extinction properties. This future study relies on the results derived in Chapter 3 to obtain a refined SMC average dust extinction curve. It also aims to obtain spatially-resolved maps of the extinction curve and $A_V$ in order to answer questions about the true distribution of SMC extinction curves.

Author : A.G.G.M. Tielens
Publisher : Springer Science & Business Media
Page : 402 pages
File Size : 21,9 MB
Release : 2012-12-06
Category : Science
ISBN : 9401103739

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The mystery of the diffuse interstellar bands has been variously a curiosity, a co nundrum, and a nuisance for astronomers in the seven decades since the features were first noticed, but recently they have become a forefront issue in astrophysics. Ever since Paul Merrill, in a series of papers starting in 1934, pointed out the interstellar and unidentified nature of the bands, a Who's Who of twentieth century astronomers have tried their hands at solving the problem of identifying the carriers. Henry Norris Russell, Pol Swings, Otto Struve, Paul Ledoux, W. W. Morgan, Walter Adams, Jesse Greenstein, Lawrence Aller, and Gerhard Herzberg all briefly entered the stage, only to move on quickly to other problems where the chances for progress appeared more realistic. In more recent times a number of equally prominent scientists have pursued the bands, but generally only as a sideline to their real astronomical research. But in the past decade, and particularly in the past three years, the view of the search for the diffuse band absorbers as an interesting but perhaps quixotic quest has changed. Today there are several astronomers, as well as laboratory chemists, who are devoting substantial research time and resources to the problem and, as perhaps the most reliable indicator of the newly elevated status of research in this field, some research grants have now been awarded for the study of the bands.

Author : Bruce T. Draine
Publisher : Princeton University Press
Page : 560 pages
File Size : 26,49 MB
Release : 2010-12-20
Category : Science
ISBN : 1400839084

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This is a comprehensive and richly illustrated textbook on the astrophysics of the interstellar and intergalactic medium--the gas and dust, as well as the electromagnetic radiation, cosmic rays, and magnetic and gravitational fields, present between the stars in a galaxy and also between galaxies themselves. Topics include radiative processes across the electromagnetic spectrum; radiative transfer; ionization; heating and cooling; astrochemistry; interstellar dust; fluid dynamics, including ionization fronts and shock waves; cosmic rays; distribution and evolution of the interstellar medium; and star formation. While it is assumed that the reader has a background in undergraduate-level physics, including some prior exposure to atomic and molecular physics, statistical mechanics, and electromagnetism, the first six chapters of the book include a review of the basic physics that is used in later chapters. This graduate-level textbook includes references for further reading, and serves as an invaluable resource for working astrophysicists. Essential textbook on the physics of the interstellar and intergalactic medium Based on a course taught by the author for more than twenty years at Princeton University Covers radiative processes, fluid dynamics, cosmic rays, astrochemistry, interstellar dust, and more Discusses the physical state and distribution of the ionized, atomic, and molecular phases of the interstellar medium Reviews diagnostics using emission and absorption lines Features color illustrations and detailed reference materials in appendices Instructor's manual with problems and solutions (available only to teachers)

Author : Endrik Krugel
Publisher : CRC Press
Page : 560 pages
File Size : 50,15 MB
Release : 2002-12-02
Category : Science
ISBN : 1420033336

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Interstellar dust grains catalyse chemical reactions, absorb, scatter, polarise and re-radiate starlight and constitute the building blocks for the formation of planets. Understanding this interstellar component is therefore of primary importance in many areas of astronomy & astrophysics. For example, observers need to understand how dust effects l