Periodic Reporting for period 5 - LEGA-C (The Physics of Galaxies 7 Gyr Ago)
Periodo di rendicontazione: 2021-02-01 al 2022-09-30
The questions addressed through this project may not be of immediate practical use to society, but do contribute to satisfying the general desire to understand the Universe, how it took its current form, and our place in it. These largest of questions start with an examination of how a Universe consisting of a featureless plasma evolved into a Universe teeming with structure in the form of galaxies, planetary systems and, perhaps, life. Understanding the formation and evolution galaxies holds key answers to these questions.
In reality projects often don't start when funding arrives and finish when the funding runs out. We are actively continuing the project and expanding the international collaboration to include prominent researchers across the world. Its scope is expanding to further comparisons with simulations, and follow-up observational programs, notably with the James Webb Space Telescope. The nature of the LEGA-C spectroscopic dataset is such that it cannot be superseded on the timescale of at least a decade, and probably more, as no further surveys of this kind are being (or indeed can be) planned. Even the newly launched James Webb Space Telescope and giant Earth-based telescopes (e.g. ESO's E-ELT) will not be able to deliver similar data for such a large sample. its legacy is assured and its impact will continue to grow over time.
The main scientific highlights are 1) the revelation of a very complex interdependency between the ages and structures of galaxies that cannot yet be reproduced by even the most advanced simulations of galaxy formation; 2) the establishment of a consistent mass scale of galaxies across half of cosmic time with a precision and accuracy of 20%; 3) the finding that galaxies of all types obey the same fundamental scaling relation between structure and velocity dispersion (a measure of mass); and 4) the first assessment of the stellar dynamical structure of galaxies in the early Universe.