EHIG · Evolution of Highly Ionized Gas Over Cosmic Time
6РП — Действия „Мария Кюри“
- Период
- 2006-02-01 → 2006-10-31
- Финансиране от ЕС
- 154 816 €
- Участници
- 1
- Схема
- SCF
Линиите свързват координатора с партньорите.
Накратко на български
Горещият йонизиран газ около далечни галактики се анализира чрез светлината от квазари, за да се открият елементи като кислород и азот. Това помага да се разбере как се разпространяват тежките елементи и галактическите ветрове в ранната Вселена.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - EHIG (Evolution of highly ionised gas over cosmic time)
As galaxy formation has proceeded across cosmic time, the collapse of matter into galactic potential wells together with supernova-driven galactic outflows has led to the generation of large volumes of interstellar plasma in and around galaxies. In this project, the observational properties of these plasma halos were studied using optical absorption line spectroscopy of background quasars. The spectra were obtained using the UVES spectrograph mounted on the Very Large Telescope at Cerro Paranal, Chile. Absorption features from five-times-ionised oxygen atoms, four-times-ionised nitrogen atoms, and three-times-ionised carbon atoms were observed at the precise redshift where galactic structures where known to reside, based on prior analysis of the lines of neutral hydrogen. Analysis of the absorption line profiles has led to quantitative measurements of the properties of highly ionised gas: its mass, phase structure, and kinematics. In this dataset we found evidence for galactic winds, in the form of ionised outflows driven at speeds of up to 1000 km/s. The most important scientific achievement is the first detection of hot interstellar gas (at temperatures above 100 000 Kelvin) in high-redshift galaxies. This plasma phase may harbour a significant fraction of all the metals produced by star formation in the early Universe.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
I propose to study the properties of the highly ionized gas in the intergalactic medium using ground-based spectroscopy of high-redshift quasars. Observations of absorption lines of the highly ionized species O VI, N V, and C IV provide a way to measure th e properties of this highly ionized gas, which is thought to harbour a significant fraction of all baryons. Using data from the UVES spectrograph on the Very Large Telescope Chile (a European facility), I aim to look for evolution in the properties of O VI absorption systems with redshift. Specifically, I will: (a) determine whether highly ionized intergalactic absorbers contain multiple gaseous phases; (b) seek an understanding of the differences between highly ionized gas at low redshift and high redshift ; c) test the predictions of cosmological simulations; and (d) investigate the origin of hot gas in Damped Lyman alpha systems (DLAs), that may represent the high-redshift precursors of galaxies like the Milky Way. This project will make use of new spectr al analysis techniques pioneered at the Institut d'Astrophysique de Paris (the host institution), which correlate the absorption in spectra separated by small angular scales on the sky. This technique will enable the spatial distribution of highly ionized gas in the high-redshift Universe to be studied for the first time.
Оригинален текст от CORDIS (на английски).
Участници
- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE · PARISКоординаторФранция
Връзки
Данни: CORDIS, © Европейски съюз