Search results for: mapping-the-galaxy-and-nearby-galaxies

Mapping the Galaxy and Nearby Galaxies

Author : Keiichi Wada
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Readers with any kind of an interest in astronomy will find this work fascinating, detailing as it does the proceedings of the symposium of the same name held in Japan in 2006. The symposium focused on mapping the interstellar media and other components in galactic disks, bulges, halos, and central regions of galaxies. Thanks to recent progress in observations using radio interferometers and optical/infrared telescopes in ground and space, our knowledge on structures of our Galaxy and nearby galaxies has been growing for the last decade.

Novel Phytoplankton Blooms

Author : Elizabeth M. Cosper
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Mapping the Galaxy and the Nearby Galaxies 26th 30th June 2006 at Ishigaki Island Okinawa Japan

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Author : James Geach
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Each night, we are able to gaze up at the night sky and look at the thousands of stars that stretch to the end of our individual horizons. But the stars we see are only those that make up our own Milky Way galaxy—but one of hundreds of billions in the whole of the universe, each separated by inconceivably huge tracts of empty space. In this book, astronomer James Geach tells the rich stories of both the evolution of galaxies and our ability to observe them, offering a fascinating history of how we’ve come to realize humanity’s tiny place in the vast universe. Taking us on a compelling tour of the state-of-the-art science involved in mapping the infinite, Geach offers a first-hand account of both the science itself and how it is done, describing what we currently know as well as that which we still do not. He goes back one hundred years to when scientists first proved the existence of other galaxies, tracking our continued improvement in the ability to collect and interpret the light that stars in faraway galaxies have emitted through space and time. He discusses examples of this rapidly accelerating research, from the initial discovery that the faint “spiral nebulae” were actually separate star systems located far beyond the Milky Way to the latest observations of the nature of galaxies and how they have evolved. He also delves into the theoretical framework and simulations that describe our current “world model” of the universe. With one hundred superb color illustrations, Galaxy is an illuminating guide to the choreography of the cosmos and how we came to know our place within it that will appeal to any stargazer who has wondered what was beyond their sight.

Curly Hare s Shapes

Author : Kathryn Smith
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An excellent interactive early learning series designed to help young readers follow simple visual and textual prompts to discover answers for themselves. They will have great fun helping Curly Hare use his special, non-detachable, Look-It-Up-Book and in doing so, will learn important lessons without having to rely on parents or teachers.

Resolved Properties of Galaxy Mergers from the MaNGA Survey

Author : Mallory D. Thorp
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The complex and diverse populations of galaxies observed today form hierarchically through past galactic mergers. Interactions between galaxies of similar masses will drastically alter the morphology, chemical composition, star-formation activity, and central black-hole accretion of their constituents. Though we can see the components and byproducts of galaxy mergers, these events endure over a timescale of hundreds of millions of years. Thus to understand the merging process from observations, astronomers are reliant on large spectroscopic surveys which will contain galaxy mergers at various stages of interaction, and those which have just experienced coalescence. Until recently, such surveys were limited to the global properties of each galaxy, constraining the global changes in chemical composition and star-formation activity, but overlooking how such changes vary across a galaxy. The advent of Integral Field Unit (IFU) spectroscopy surveys provides spatially resolved spectroscopic properties for thousands of galaxies for the first time. This thesis presents analysis of galaxy mergers from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) IFU spectroscopy survey. Enhancements and deficits in star-formation rate and metallicity, as a result of the interaction, are determined for each spatial pixel containing a spectrum (spaxel) based on well established relationships with stellar mass density. These offsets are then compressed into radial profiles to quantify how the effects of an interaction vary as a function of radius. A sample of 36 post-mergers are, on average, enhanced out to ~2 effective radii, though individual galaxies can be enhanced or suppressed in the outskirts depending on the global star-formation rate of the galaxy. The metallicity is uniformly suppressed in post-merger galaxies, in concordance with the global SFR enhancement. A sample of galaxy pairs is identified with cuts in the projected separation, the line of sight velocity difference, and the mass ratio of the interaction. I develop a method to deblend close galaxy pairs that are on the same IFU observation, and remove contribution from the companion galaxy in the radial profile. Radial profiles of SFR and metallicity offsets for the pairs sample, binned by projected separation, confirm that central enhancements in SFR increase as separation decreases. Behaviour in the outskirts is more varied, and does not appear to correlate with the projected separation or the mass ratio of the interaction. Metallicity offsets display a similar issue, showing no clear correlation with separation or mass ratio. Such ambiguity implies that multiple characteristics of the interaction and its components are required to predict the spatial changes in a galaxy merger. I propose projects that could shed light on these ambiguities. The most recent release of MaNGA will double the sample size of mergers, possibly homogenizing projected separation and mass ratio bins that may be dominated by a particular population. An analysis of interacting galaxies that do not have mass ratio measurements, but very small projected separations and highly disturbed morphologies, could provide understanding of the transition between the very end of an interaction and the state of the galaxy post-coalescence. I also propose a more complex analysis of the asymmetry of IFU spectroscopy data products, which until now have been simplified with radial profiles. Lastly, I emphasize the importance of follow up studies of the resolved molecular gas properties of merging galaxies to discern whether gas reservoir, depletion time, or both are driving the change in star-formation rate.

Secular Evolution of Galaxies

Author : Jesús Falcón-Barroso
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Graduate-level text on galaxy evolution, one of the most popular research topics in astrophysics, with chapters contributed by leading astronomers.

Principles of Physical Cosmology

Author : P. J. E. Peebles
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The classic introduction to physical cosmology from Nobel Prize–winning physicist P. J. E. Peebles Principles of Physical Cosmology is the essential introduction to this critical area of modern physics, written by a leading pioneer who has shaped the course of the field for decades. P. J. E. Peebles provides an authoritative overview of the field, showing how observation has combined with theory to establish the science of physical cosmology. He presents the elements of physical cosmology, including the history of the discovery of the expanding universe; surveys the cosmological tests that measure the geometry of space-time, with a discussion of general relativity as the basis for these tests; and reviews the origin of galaxies and the large-scale structure of the universe. Now featuring Peebles's 2019 Nobel lecture, Principles of Physical Cosmology remains an indispensable reference for students and researchers alike.

Literature 1981

Author : Siegfried Böhme
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From the Realm of the Nebulae to Populations of Galaxies

Author : Mauro D'Onofrio
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In order to outline possible future directions in galaxy research, this book wants to be a short stopover, a moment of self-reflection of the past century of achievements in this area. Since the pioneering years of galaxy research in the early 20th century, the research on galaxies has seen a relentless advance directly connected to the parallel exponential growth of new technologies. Through a series of interviews with distinguished astronomers the editors provide a snapshot of the achievements obtained in understanding galaxies. While many initial questions about their nature have been addressed, many are still open and require new efforts to achieve a solution. The discussions may reveal paradigms worthwhile revisiting. With the help of some of those scientists who have contributed to it, the editors sketch the history of this scientific journey and ask them for inspirations for future directions of galaxy research.

Astronomy and Astrophysics Abstracts

Author : S. Böhme
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Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documenta tion of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, compared to which our system of accumu lating abstracts for about six months offers the advantage of greater convenience for the user. Volume 31 contains literature published in 1982 and received before July 15, 1982; some older literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bouska, Prague, who surveyed journals and publications in Czech and supplied us with abstracts in English .

Triggered Star Formation in a Turbulent Interstellar Medium IAU S237

Author : International Astronomical Union. Symposium
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New stars form in the dense turbulent gas clouds of galaxies, and the formation of these clouds is the subject of the IAU S237. This book is the most up-to-date review of all aspects of cloud and star formation, and one of the few compendiums available on ISM turbulence.

The Central Regions of the Galaxy and Galaxies

Author : Yoshiaki Sofue
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Proceedings of the 184th Symposium of the International Astronomical Union, held in Tokyo, Japan, 18-22 August 1997

On the Shores of the Unknown

Author : Joseph Silk
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Resolving Black Hole and Star Formation Activity in Nearby Galaxies

Author : Mallory Elyse Molina
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Black hole accretion and star formation exhibit different properties with observed spatial scale. To fully understand them, we must consider the local environment's impact on measured global properties. My dissertation focuses on the spatially resolved excitation mechanisms that power observed emission, and the dust that obscures it. Low ionization nuclear emission regions (LINERs) are common in nearby galaxies, and are often explained by photoionization by low luminosity active galactic nuclei (AGNs). But this energy source is not sufficient to power the observed emission lines that define LINERs on 100 pc scales. Using the Hubble Space Telescope, I resolved the nuclear regions of three nearby LINERs on the 10 pc scale to track the dominant power source with distance from the nucleus. The resulting physical model involved photoionization from the AGN within the central 20 pc, and shock excitation at larger distances. I conclude that integrated LINER-like emission can be explained by a combination of photoionization by the AGN and shocks on different spatial scales.The advancement and cessation of star formation within a galaxy is vital for understanding galaxy evolution. Furthermore, the rest-frame ultra violet (UV) and optical bands are crucial for disentangling the star formation history, metallicity and age of systems. To that end, I construct a data set of 150 galaxies with Swift Ultra Violet Optical Telescope (UVOT) UV photometry and Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory (SDSS-IV/MaNGA) optical IFU spectroscopy. I present properties of the data set, and use it to quantify relations between the UV and H-alpha star formation rate proxies.Unfortunately, our understanding of star formation is highly dependent on dust attenuation, which itself depends on the spatial scales and properties on which it is observed. This is especially true in the UV band, where the attenuation laws from literature differ dramatically. Therefore, any attempts to understand star formation histories in using the Swift+MaNGA data catalog will be subject to this systematic. To address this, I studied the attenuation law of kiloparsec-sized star forming regions using a subset of 29 galaxies. I compared the attenuation from the individual regions with that of the parent galaxy, and find the attenuation of the optical nebular emission is similar between the two physical scales, but that of the UV stellar continuum is not. I attribute this difference to sightline-dependencies of the stellar continuum attenuation and dilution of the UV light by older stars.Through spatially resolved studies of black hole accretion and star formation activity in nearby galaxies, my dissertation work provides context for the integrated properties of nearby galaxies, and provides context for future statistical surveys.

Clusters and Groups of Galaxies

Author : F. Mardirossian
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The large-scale structure of the Universe and systems Clusters, and Groups of galaxies are topics like Superclusters, They fully justify the meeting on "Clusters of great interest. and Groups of Galaxies". The topics covered included the spatial distribution and the clustering of galaxies; the properties of Superclusters, Clusters and Groups of galaxies; radio and X-ray observations; the problem of unseen matter; theories concerning hierarchical clustering, pancakes, cluster and galaxy formation and evolution. The meeting was held at the International Center for Theoretical Physics in Trieste (Italy) from September 13 to September 16, 1983. It was attended by about 150 participants from 22 nations who presented 67 invited lectures (il) and contributed papers (cp), and 45 poster papers (pp). The Scientific Organizing Committee consisted of F. Bertola, P. Biermann, A. Cavaliere, N. Dallaporta, D. Gerba1, M. Hack, J . V . Peach, D. Sciama (Chairman), G. Setti, M. Tarenghi. We are particularly indebted to D. Sciama, A. Cavaliere and F. Bertola for their work of coordination. We were acting as the three members of the Local Organizing Committee. Moreover, we are pleased to thank the Chairmen of the Sessions (M. Hack, N. Da11aporta, G. Burbidge, B. Mills, M. Rees, P. Biermann, L.Z. Fang, L. Gouguenheim) for their valuable help.

Galaxies and the Cosmic Frontier

Author : William Howard Waller
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For the past twelve billion years, galaxies have governed the Universe, bringing form to the firmament, light to the void. Each one a giant system of as many as hundreds of billions of stars, the galaxies are the building blocks of the cosmos, and through new data from modern telescopes—including the Hubble Space Telescope—we are discovering dizzying new facts about how they formed, how they evolve, and what they are made of. This book acquaints readers with these facts and findings--and with what they can tell us about the lives of galaxies over cosmic time, from their emergence shortly after the Hot Big Bang to their ongoing gyrations and transmutations.

3 D Atlas of Stars and Galaxies

Author : Richard Monkhouse
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This astronomical atlas features not only conventional star and galaxy maps, but also spectacular three-dimensional stereographs (glasses provided). The book contains three sets of comprehensive full-sky maps that cover local space, regional space, and distant space -- with over 20,000 galaxies. All the stereographs have been derived from the most accurate data available, including results from the Hipparcos satellite, and can be used to measure the approximate distances between the objects depicted. The distant space maps represent one of the most complete mappings of the galaxies available to amateur astronomers, and their accompanying three-dimensional views provide tantalising glimpses of structure at the largest scale of the universe.

The Nine Numbers of the Cosmos

Author : Michael Rowan-Robinson
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How old is the universe? How far away are the galaxies and how fast are they travelling away from us? What is dark matter and why do astronomers think it pervades the universe? How heavy is the vacuum? How do galaxies form? Michael Rowan-Robinson answers these and many more questions in a highly original and intriguing way. He encapsulates our current knowledge (both what we do and don't know) of the origin and the nature of the universe into nine numbers. These cosmic numbers appear to be independent characteristics of our universe and include its age, the Hubble constant (a measure of its rate of expression), and the density of matter in the universe. Only one of the nine numbers is known with real precision, and four of them only poorly known. The complex ideas that underpin modern cosmology such as the origin of the elements and quantum theory are explained clearly and accessibly, and more speculative ideas like inflation and superstrings are also covered, but with a refreshing scepticism. While most of what we know has been learnt during the 20th century, Rowan-Robinson provides a historical perspective, paying homage to the achievements of the Greeks, Renaissance astronomers, and the age of Newton. He ends the book with a look to the future, predicting that with the further space missions we will accurately know the nine numbers described in this book by the year 2015, but concludes that the origin of the Big Bang itself will still be a mystery by the end of the twenty-first century, and perhaps even in the year 3000.

Astronomy in India A Historical Perspective

Author : Thanu Padmanabhan
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India has a strong and ancient tradition of astronomy, which seamlessly merges with the current activities in Astronomy and Astrophysics in the country. While the younger generation of astronomers and students are reasonably familiar with the current facilities and the astronomical research, they might not have an equally good knowledge of the rich history of Indian astronomy. This particular volume, brought out as a part of the Platinum Jubilee Celebrations of Indian National Science Academy, concentrates on selected aspects of historical development of Indian astronomy in the form of six invited chapters. Two of the chapters – by Balachandra Rao and M.S. Sriram – cover ancient astronomy and the development of calculus in the ancient Kerela text Yuktibhasa. The other four chapters by B.V. Sreekantan, Siraj Hasan, Govind Swarup and Jayant Narlikar deal with the contemporary history of Indian astronomy covering space astronomy, optical astronomy, radio astronomy and developments in relativistic astrophysics. These chapters, written by experts in the field, provide an in-depth study of the subject and make this volume quite unique.