ZSIM1GALDYN · Merging, outflows, or rotation? Early galaxy evolution in the context of dark matter assembly
6РП — Действия „Мария Кюри“
- Период
- 2006-11-01 → 2008-10-31
- Финансиране от ЕС
- 142 866 €
- Участници
- 1
- Схема
- EIF
Линиите свързват координатора с партньорите.
Накратко на български
Процесите по формиране на ранните галактики се изследват чрез анализ на газовите потоци и влиянието на свръхмасивните черни дупки. Това помага да се разбере как се регулира раждането на звездите и защо някои масивни галактики спират да се развиват.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - ZSIM1GALDYN (Merging, Outflows, or Rotation? Early galaxy evolution in the context of dark matter assembly)
Unlike many other scientists, astronomers are in a lucky position of directly witnessing most of the evolutionary history of their prime research target: the Universe. For example, we know that galaxies evolved primarily in the early universe, and that most of the star formation and galaxy assembly was already completed when the universe was about half its present age. Since we covered different cosmic epochs with our project, we were able to witness this decline in activity directly. Thanks to modern technology, and in particular the recently developed 'integral-field spectroscopy', we are now able to not only study the 'When?' but also the 'How?' of galaxy formation in the early universe. Which physical processes shaped the galaxies we see today? As part of this project, we found that gas physics plays a major role that cannot be neglected, altering the physical gas conditions, and often even leading to galaxy-scaled 'winds' of outflowing gas. The active star formation in galaxies in the early universe may well be self-regulated, through the enormous energy output of supernovae and young stars, which may balance the further collapse of gas into giant molecular clouds and then into stars. However, in the most massive galaxies such processes are not sufficient. In these galaxies, we could show that a yet more powerful process is at work, namely winds triggered by the activity of the central supermassive black hole. These appear to be able to quench star formation in the most extreme starbursts in the universe, by removing most of the available gas, and hence the 'fuel' available to star formation. Thus, we witnessed the 'final fireworks' in the history of the most massive galaxies in the universe, which at low redshift appear 'old, red, and dead'.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
What are the fundamental mechanisms of large-scale structure formation and galaxy evolution in the universe? While dark-matter halo collapse dominates on the largest scales, matter assembly becomes non-linear at mass scales of individual galaxies, where baryons play a non-negligible role.As baryons accumulate near the centre of the dark matter potential through gas infall and merging of dark-matter haloes, they cause hydrodynamic 'feedback', i.e. outflows triggered by intense star-formation ('starburst-driven winds') and by powerful active galactic nuclei (AGN). Each process will influence the large-scale gas dynamics in the galaxy.To elucidate the relative importance of these mechanisms and their impact on galaxy evolution in the early universe (when structure assembly proceeded most rapidly), we propose to study the spatially resolved emission line gas kinematics and chemical properties in a moderately large sample of galaxies at redshifts z=0.5-1.25. This range corresp onds to look-back times of 5 to 8 Gyr, about half the age of the universe, where the tails of high-redshift and low-redshift galaxy populations overlap.The German fellow will carry out this project at the Paris-Meudon observatory and within a Franco-Italian-German collaboration with participation of Swedish and US experts, and a novel observational approach: By combining data obtained with the VLT integral-field spectrographs GIRAFFE in the optical and SINFONI in the near-infrared, we will for the first time map the two-dimensional distribution of gas kinematics, metallicity, extinction, star-formation rates, and electron densities in galaxies in the early universe.We will thus be able to robustly distinguish virialized rotation from galaxy mergers and winds, and test various cosmological models of galaxy formation. Most importantly, we will probe the fundamental structural parameters of dark matter halos as predicted by dark-matter cosmogonies, specifically
Оригинален текст от CORDIS (на английски).
Участници
- OBSERVATOIRE DE PARIS-MEUDON · PARISКоординаторФранция
Връзки
Данни: CORDIS, © Европейски съюз