Download Free Early Disk Galaxy Formation From Jwst To The Milky Way Iau S377 Book in PDF and EPUB Free Download. You can read online Early Disk Galaxy Formation From Jwst To The Milky Way Iau S377 and write the review.

Our comprehension of the assembly and evolution of galaxies has witnessed remarkable advancements in recent years. While the Gaia spacecraft has provided unprecedented knowledge of the Milky Way's assembly, the launch of the James Webb Space Telescope (JWST) has propelled the study of galaxy evolution into an exciting new era. Early discoveries of JWST have revealed high-redshift galaxies that defy our expectations. These conundrums must be resolved through multi-wavelength observations, simulations, and theoretical models as emphasized in this volume, which contains a selection of papers presented at IAU Symposium 377, held about two years after the launch of JWST. These papers showcase studies of galaxy formation, evolution, interaction, chemical abundances and stellar populations from cosmic down to the Milky Way. These proceedings offer an updated view of recent advances and current problems and is suitable for both active researchers in the field and graduate students.
The first three billion years of cosmic time were the prime epoch of galaxy formation. Characterising galaxies at this epoch is therefore crucial to achieving a major goal of modern astrophysics: to understand how galaxies such as our Milky Way emerged from the primordial density fluctuations in the early Universe and how they evolved through cosmic time. Recent major international investments in observing facilities such as the Atacama Large Millimetre Array (ALMA) and the James Webb Space Telescope (JWST) promise to provide the next leap in our understanding of this topic. This volume gathers the scientific contributions to the International Astronomical Union Symposium 352, which was devoted to this topic. The community of theoretical and observational experts discuss how we can make the most of ALMA and JWST synergies in advancing our understanding of galaxy evolution in the young Universe.
The paradigm of a dark energy- and dark matter-dominated Universe, with the hierarchical merger scenario for the formation of galaxies, has scored impressive successes in matching the observed Universe. However, the theory fails to explain the difficulty in generating ordinary disk galaxies such as the Milky Way, suggesting that some important physics must be missing in current models. IAU Symposium 254 was organized to address this question, gathering researchers from an unusually broad range of fields, from cosmology to interstellar matter, and the formation and evolution of stars. High-class reviews, lectures and posters combine to define the frontiers in the field and point the way to new avenues of research. This volume presents a unique set of succinct overviews illuminating the full range of topics in this very active field. It also honors Danish astrophysicist Bengt Strömgren (1908-1987), who laid much of the foundation for this entire field.
This volume contains the updated and expanded lecture notes of the 37th Saas-Fee Advanced Course organised by the Swiss Society for Astrophysics and Astronomy. It offers the most comprehensive and up to date review of one of the hottest research topics in astrophysics - how our Milky Way galaxy formed. Joss Bland-Hawthorn & Ken Freeman lectured on Near Field Cosmology - The Origin of the Galaxy and the Local Group. Francesca Matteucci’s chapter is on Chemical evolution of the Milky Way and its Satellites. As designed by the SSAA, books in this series – and this one too – are targeted at graduate and PhD students and young researchers in astronomy, astrophysics and cosmology. Lecturers and researchers entering the field will also benefit from the book.
Scientists in the late twentieth century are not the first to view galaxy formation as a phenomenon worthy of explanation in terms of the known laws of physics. Already in 1754 Kant regarded the problem as essentially solved. In his Univerlal Natural Hutory and Theory 0/ the H eaven$ he wrote; "If in the immesurable space in which all the suns of the Milky Way have formed themselves, we assume a point around which, through some cause or other, the first formation of nature out of chaoo began, there the largest mass and a body of extraordinary attraction will have arisen which has thereby become capable of compelling all the systems in the process of being formed within an enormous sphere around it, to fall towards itself as their centre, and to build up a system around it on the great scale . . . . Observation puts this conjecture almost beyond doubt. " More than 200 years later, a similar note of confidence was voiced by Zel'dovicb at an IAU symposium held in Tallin in 1911; "Extrapolating . . . to the next symposium somewhere in the early eighties one can be pretty sure that the question of the formation of galaxies and clusters will be solved in the next few years. " Perhaps few astronomers today would share Kant's near certainty or feel that Zel'dovich's prophecy has been fulfilled, Many, however, will sympathize with the optimistic olltlook of these two statements.
Abstract: Current and next generation surveys of the Milky Way promise to revolutionize our observational perspective of the Galaxy. My dissertation uses a suite of N-body and SPH simulations of disk galaxies to make testable predictions of the assembly history of the Milky Way and identify observational probes that take advantage of the forthcoming data. APOGEE, an infrared survey of the Galaxy and a component of the SDSS-III, will measure the distance, radial velocity, and multi-element chemistry of 10^5 stars located throughout the Galaxy, making it particularly well suited for comparison with simulations. We first use a fuel-consumption argument to constrain the integrated luminosity of the TP-AGB phase; the energy release in this phase is a major uncertainty in stellar population synthesis models. Our initial numerical investigation explores how the minor mergers expected in Lambda-CDM and inherent properties of stellar disks affect the dynamics of stellar radial migration- an essential ingredient in understanding the evolution of the Milky Way and disk galaxies in general. We discover that the resonances and mechanisms responsible for migration are different in isolated and satellite-bombarded galaxies, resulting in distinct migration patterns and potential observational signatures of accretion events. Continuing our development of tools to describe the chemo-dynamics of the disk, we construct statistics to measure overdensities and characterize outliers in the distance, radial velocity projection of phase space. I discuss mock APOGEE observations of our numerical simulations and demonstrate that our statistics can begin to discriminate between significant galaxy formation mechanisms given the data available in the near term. Finally, we use a state of the art cosmological simulation to describe the evolution of mono-age stellar populations and their eventual assembly into a galaxy resembling the Milky Way. Galaxy formation theory faces the exciting challenge of an unprecedented level of statistical scrutiny: imminent and ongoing surveys such as SEGUE, RAVE, APOGEE, LAMOST, and HERMES offer an extraordinary opportunity to unravel the formation history of the Milky Way.
The dynamical evolution of substructure within dark matter halos is of central importance in determining many aspects of galaxy formation and galaxy evolution in cold dark matter cosmologies. The overall sequence in which the different stellar components of galaxies are assembled, the survival of galactic disks, the number of dwarf satellites orbiting giant galaxies, and the nature of stellar material in galactic halos all depend on the dynamics of halo substructure. In this thesis, I develop an analytic description of the evolution of substructure within a dark matter halo, and use it to construct a semi-analytic model of the formation and evolution of disk galaxies. Substructure within an individual halo is modelled as a set of distinct subhalos, orbiting in a smooth background. These subhalos evolve through three main processes: dynamical friction, tidal mass loss, and tidal heating. By including analytic descriptions of these three processes explicitly in a simple orbital integration scheme, it is possible to reproduce the results of high-resolution numerical simulations at a fraction of the computational expense. The properties of a subhalo can be estimated with an accuracy of 20%, until it has lost most of its mass or been disrupted. Using this description of satellite dynamics, I construct a semi-analytic model for the evolution of a galaxy or cluster halo. I show that this model reproduces the basic features of numerical simulations, and use it to investigate two major problems in current galaxy formation scenarios: the prediction of excessive substructure in galaxy halos, and the survival of galactic disks in halos filled with substructure. I show that the small number of dwarf galaxies observed in the Local Group can be explained by considering the effects of reionisation on star formation in small halos. The stellar luminosities predicted in this case match the observed luminosities of local satellites. The predicted spatial distribution, sizes and characteristic velocities of dwarf galaxies are also consistent with those observed locally. Many of these satellite galaxies are disrupted by tidal stripping or encounters. I investigate the properties of their debris, and show that its total mass and spatial distribution are similar to those of the stellar halo of the Milky Way. Furthermore, the stars in this debris are mainly old, satisfying another observational constraint on models of galaxy formation. Some satellites have been disrupted fairly recently, however, suggesting that coherent tidal streams may still be visible at the present day. Finally, I investigate the effects of encounters on the central disk within the main halo. I find that the rate of disruptive encounters drops off sharply after the galaxy is assembled, such that the typical disk has remained undisturbed for the past 8-10 billion years. Less disruptive encounters are more common, and disks are often heated as they re-form after their last disruption, producing components like the thick disk of the Milky Way. These results may resolve the long-standing uncertainty about disk ages in hierarchical, cold dark matter cosmologies. It is less clear whether the bulge-to-disk mass ratios predicted by the model, for the currently favoured LCDM cosmology, are consistent with observations. The relative mass of the bulge in typical disk galaxies may place an upper limit on the age of their stellar contents.
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.
The oldest stars in our Galaxy contain crucial information about its formation and the early Universe. Simulations predict that the oldest stars are likely to be located in the central regions of galaxies. Furthermore, nucleosynthetic predictions for the first stars indicate large yields of carbon, suggesting that the oldest stars may be Carbon-Enhanced Metal-Poor (CEMP) stars. Studying the chemo-dynamical properties of metal-poor inner Galaxy stars and CEMP stars can illuminate their origins and, in turn, inform our models of first star formation and galaxy evolution. In this dissertation, I complete a three-part survey entitled Chemical Origins of Metal-poor Bulge Stars (COMBS). COMBS I and COMBS III focused on the chemical abundance analysis of ~600 metal-poor stars using VLT/FLAMES spectra, while COMBS II focused on the dynamics of these stars. These studies show evidence that the population that enriched the old metal-poor inner Galaxy stars had a more top-heavy IMF than the typical Milky Way population. Furthermore, my results indicate that secular disk evolution may be more important in early galaxy evolution than previously thought. However, the COMBS survey did not detect any CEMP stars in the inner Galaxy. To investigate this further, I used machine learning to identify an all-sky sample of millions of CEMP stars using Gaia DR3. In addition, my dissertation puts new constraints on the length and pattern speed of the Milky Way's bar by developing a novel orbit integration method which, in turn, improves the precision and accuracy of inner Galaxy dynamical analysis. In total, my dissertation brings new insights into the formation of the Galaxy, especially the bulge, and provided constraints on the formation of the first stars through the chemo-dynamics of ancient stars
The most comprehensive and up-to-date survey available on stellar structure and evolution, with a special emphasis on currently unsolved problems.