Download or read book Solo Dwarf Galaxy Survey written by Clare Higgs and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Galaxy evolution depends on a diverse suite of factors, from the environment in which the galaxy exists to the number of supernovae that explode throughout its history. The structure and stellar populations present will also be altered by a galaxy's merger history, stellar mass, star formation rate, among other influences. Some factors, like mergers, are dependent on the environment of the galaxy, while others, like feedback from star formation, are intrinsic to the galaxy themselves. Dwarf galaxies are sensitive to many of these factors due to their smaller masses, hence shallower potential wells. Dwarfs are also interesting in themselves as the least massive structures that can form stars, forming the faint limit of galaxy types. There is some indication that the evolutionary pathway of dwarfs might be different than their more massive counterparts. Indeed, some dwarfs may be the stripped remnants of larger galaxy after a major interaction. Regardless, dwarfs are thought to be the building blocks of larger galaxies via hierarchical galaxy formation and understanding these small dwarfs helps us build a more complete picture of galaxy formation and evolution at all masses. As dwarfs generally have low stellar mass, they are very faint. Our most complete sample of dwarfs is therefore restricted to those that are nearby. These nearby systems are dominated by dwarfs satellite to the Milky Way and M31. However, the evolution of these satellites will be greatly influenced by their massive host. By studying nearby isolated dwarfs, we can try to separate the secular evolutionary processes of dwarfs from the influence of their larger host. Additionally, stellar populations can be resolved in these nearby galaxies, and so their structures can be probed to much fainter regimes than integrated light studies allow.The Sagittarius Dwarf Irregular Galaxy (Sag DIG) is one of the most isolated, low mass galaxies, located at the edge of the Local Group. Its isolation from other galaxies coupled with its relative proximity provide an excellent opportunity to study the intrinsic properties of this low mass system. We preform an in-depth analysis of its resolved stellar populations and its structural properties as the first galaxy in the larger dataset, Solitary Local Dwarfs Survey (Solo). Solo is a wide field photometric study targeting every isolated dwarf galaxy within 3 Mpc of the Milky Way. Solo is based on (u)gi multi-band imaging from CFHT/MegaCam for northern targets, and Magellan/Megacam for southern targets. All galaxies fainter than M ~ -18 (in the V band) situated beyond the nominal virial radius of the Milky Way and M31 (> 300 kpc) are included in this volume-limited sample, for a total of 42 targets. For Sag DIG, we provide updated estimates of its central surface brightness and integrated luminosity, and trace its surface brightness profile to a level fainter than 30 mag./sq.arcsec. Sag DIG is well described by a highly elliptical (disk-like) system following a single component Sersic model. However, a low-level distortion is present at the outer edges of the galaxy that, were Sag DIG not so isolated, would likely be attributed to some kind of previous tidal interaction. Further, we find evidence of an extremely low level, extended distribution of stars beyond ~5 arcmins (> 1.5 kpc) that suggests Sag DIG may be embedded in a very low density stellar halo. We compare the stellar and HI structures of Sag DIG, and discuss results for this galaxy in relation to other isolated, dwarf irregular galaxies in the Local Group. Sag DIG, and the similarly isolated dwarf Aquarius, both have HI distributions that are more circular than their stellar components. In contrast, Wolf - Lundmark - Mellote (WLM), another isolated but slightly more massive dwarf, has stellar and HI components that trace each other well. Sag DIG and Aquarius also differ in that there is no signature of rotation in the HI of Sag DIG, while there is clear rotation in both the HI and stellar component for Aquarius. These preliminary comparisons demonstrate some of the potential analysis which will be possible on a much larger scale with the full Solo Survey.
Download or read book Dwarfs Among Giants written by Clare Higgs and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis attempts to untangle, as best as possible, the importance of internally-driven evolutionary mechanisms relative to externally-driven effects, in shaping the structure and properties of the smallest observable galaxies. All galaxies are influenced by internal processes, such as feedback from star formation and the infall of gas or lack thereof, as well as environmental processes, like tides and ram pressure stripping. The smallest galaxies - dwarfs - are highly susceptible to all such processes, and their resulting structure is the summation of all prior events. I use nearby dwarf galaxies of the Local Group as test cases, focusing on those which are separated from the massive galaxies (like the Milky Way) and can be considered as "isolated''. These dwarfs are observed as part of the Solitary Local (Solo) Dwarf Galaxy Survey. Solo dwarfs will have spent the majority of their time as isolated systems, hence their properties should generally reflect their "intrinsic nature", unperturbed and unaffected by interactions with other systems. This survey was designed to focus on the old stellar populations present in these galaxies, in order to characterize their faint and extended structures. These old stellar populations should carry the hallmarks of the dwarfs' histories. By comparing the observed properties of Solo dwarfs with dwarfs currently in close proximity to a large host galaxy (i.e., the M 31 and Milky Way satellites), it should be possible to determine what aspects of the properties of dwarfs are most affected by environmentally-driven processes. The Local Group is the ideal regime in which to study these faint features, as the dwarfs' close proximity to us presents an opportunity to fully characterize these galaxies. However, the number of dwarfs in the Local Group is limited, with several galaxies (e.g. IC 10 or Sag dSph) being the unique example of their "type" locally observable. This limited sample emphasizes the need for careful, homogeneous observations and analysis, such that comparisons between this small, yet highly diverse, snapshot of galaxies accurately reflects the true nature of these dwarfs. I have homogeneously analyzed the 12 closest Solo dwarfs observable from the northern hemisphere, resulting in a consistently derived dataset. I determine fundamental properties, like distances, and characterize the structure of the dwarfs. I explore the possibility that the dwarfs may be more consistent with a two component profile, rather than one, finding that they are largely well characterized by a single Sérsic profile. I then compare these isolated dwarfs with the well-studied satellites of the Milky Way and M 31, primarily using two other homogeneous surveys; the MegaCam Survey of Outer Halo Objects and the Pan-Andromeda Archaeological Survey respectively. Examining each property (e.g. ellipticity, central surface brightness, or Sérsic radius) individually, we find no statistically significant differences between each group. However, when considering parameters in combination (e.g. absolute magnitude as a function of Sérsic radius), we see increased scatter in the satellite population, indicative of the impact of a massive host galaxy on the dwarfs, likely via tidal effects. The comparison between satellites and isolated dwarfs hones in on the impact of a massive galaxy in close proximity. Of course, processes within and surrounding the dwarf itself can also alter the dwarf. I look at the star formation histories and gas content of the dwarfs to explore the connection between internal and external processes in these small galaxies. Finally, I search for substructure in the form of satellites of dwarf galaxies, globular clusters and extended tidal features, all which inform about the dwarf's isolation, environment and history. Collectively, I generate comprehensive and detailed inspections of Local Group dwarfs and aim to understand them as products of their environment.
Download or read book Outskirts of Galaxies written by Johan H. Knapen and published by Springer. This book was released on 2017-07-09 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of invited reviews written by world-renowned experts on the subject of the outskirts of galaxies, an upcoming field which has been understudied so far. These regions are faint and hard to observe, yet hide a tremendous amount of information on the origin and early evolution of galaxies. They thus allow astronomers to address some of the most topical problems, such as gaseous and satellite accretion, radial migration, and merging. The book is published in conjunction with the celebration of the end of the four-year DAGAL project, an EU-funded initial training network, and with a major international conference on the topic held in March 2016 in Toledo. It thus reflects not only the views of the experts, but also the scientific discussions and progress achieved during the project and the meeting. The reviews in the book describe the most modern observations of the outer regions of our own Galaxy, and of galaxies in the local and high-redshift Universe. They tackle disks, haloes, streams, and accretion as observed through deep imaging and spectroscopy, and guide the reader through the various formation and evolution scenarios for galaxies. The reviews focus on the major open questions in the field, and explore how they can be tackled in the future. This book provides a unique entry point into the field for graduate students and non-specialists, and serves as a reference work for researchers in this exciting new field.
Download or read book Star forming Dwarf Galaxies and Related Objects written by D. Kunth and published by Atlantica Séguier Frontières. This book was released on 1985 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Survey for Resolved Milky Way Dwarf Galaxy Satellites written by Beth Willman and published by . This book was released on 2003 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dust at Low metallicity written by Dale Clayton Jackson and published by . This book was released on 2007 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science and Faith in Dialogue written by Frederik van Niekerk and published by AOSIS. This book was released on 2023-03-01 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Science and Faith in Dialogue presents a cogent, compelling case for concordance between science and theism. The term theism refers, in this book, to the belief in God's existence. Within theology, the term theism is often used to convey a range of presuppositions about the nature and attributes of God. Based on scientific and natural theological perspectives, two pillars of natural theology are revisited: the Cosmological Argument and the Argument from Design. The book argues that modern science provides undeniable evidence and a scientific basis for these classical arguments to infer a rationally justifiable endorsement of theism as being concordant with reason and science – nature is seen as operating orderly on comprehensible, rational, consistent laws, in line with the conviction that God is Creator.
Download or read book Dwarf Galaxies and Their Environment written by Klaas Sjoerds Boer and published by . This book was released on 2001 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dwarf Galaxies written by European Southern Observatory and published by . This book was released on 1994 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dwarf Galaxies and Their Environment written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Ultraviolet Survey of the DA White Dwarf Population of the Galaxy written by Renae E. Wall and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Very Low Mass Stars and Brown Dwarfs written by Rafael Rebolo and published by Cambridge University Press. This book was released on 2000-11-27 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a state-of-the-art review of our current knowledge of brown dwarfs and very low-mass stars. The hunt for and study of these elusive objects is currently one of the most dynamic areas of research in astronomy for two reasons. Brown dwarfs bridge the gap between stars and planets, and they may constitute an important part of the 'dark matter' of the Universe. This volume presents review articles from a team of international authorities who gathered at a conference in La Palma to assess the spectacular progress that has been made in this field in the last few years.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1991 with total page 1530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Universe written by DK and published by Penguin. This book was released on 2020-09-08 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marvel at the wonders of the universe, from stars and planets to black holes and nebulae, in this exploration of our solar system and beyond. Universe opens with a look at astronomy and the history of the Universe, using 3D artworks to provide a comprehensive grounding in the fundamental concepts of astronomy, including the basic techniques of practical astronomy. The core of the book is a tour of the cosmos covering the Solar System, the Milky Way, and galaxies beyond our own. Explanatory pages introduce different celestial phenomena, such as galaxies, and are followed by catalogs that profile the most interesting and important examples. A comprehensive star atlas completes the picture, with entries on each of the 88 constellations and a monthly sky guide showing the night sky as it appears throughout the year as viewed from both the northern and southern hemispheres.
Download or read book A Fortunate Universe written by Geraint F. Lewis and published by Cambridge University Press. This book was released on 2016-10-06 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last forty years, scientists have uncovered evidence that if the Universe had been forged with even slightly different properties, life as we know it - and life as we can imagine it - would be impossible. Join us on a journey through how we understand the Universe, from its most basic particles and forces, to planets, stars and galaxies, and back through cosmic history to the birth of the cosmos. Conflicting notions about our place in the Universe are defined, defended and critiqued from scientific, philosophical and religious viewpoints. The authors' engaging and witty style addresses what fine-tuning might mean for the future of physics and the search for the ultimate laws of nature. Tackling difficult questions and providing thought-provoking answers, this volumes challenges us to consider our place in the cosmos, regardless of our initial convictions.
Download or read book The Andromeda Galaxy written by Paul Hodge and published by Springer Science & Business Media. This book was released on 1992-06-30 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Andromeda Galaxy, or M31, is an attractive galaxy for astronomers. It is close to us, it is of about the size of our galaxy, it provides some intriguing observational puzzles because the galaxy is nearly edge-on, and many objects can be studied in detail, because they are still sufficiently bright. With the current developments in instrumentation with which increasingly detailed studies of the Andromeda Galaxy can be made, this book provides a solid foundation for the start of new observations. This book is a mine of information about M31. It can be used as a reference by insiders, and at the same time it provides easy access for newcomers to the field.
Download or read book Formation and Evolution of Galaxy Outskirts IAU S321 written by Armando Gil de Paz and published by Cambridge University Press. This book was released on 2017-02-28 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The borders between galaxies and the almost empty intergalactic medium are ill-defined regions where gas struggles to form stars. The proceedings of IAU Symposium 321 summarize our current understanding of the rarefied universe and prepare for the optimal exploitation of upcoming astronomical instruments. They discuss the most recent advances in the study of the stellar, dust and gas content of galaxy outskirts, going from resolved stellar populations in the Milky Way and in the Local Group to the study of high-redshift systems. Such a broad approach, both in terms of galaxy components and evolutionary epochs, is necessary to take full advantage of the recent discoveries made by facilities at all wavelengths, to deepen our knowledge of the assembly and evolution of these elusive regions and to establish their role within the evolution of galaxies as a whole and their interactions with the surrounding intergalactic medium.
