Metallicities of high redshift GRB hosts: The case of GRB 100219A
Résumé
GRB 100219A at z=4.667 has been the highest redshift gamma-ray burst observed with the X-shooter spectrograph up to now. The spectrum covering the range from 5000 to 24 000 Åand a large number of absorption lines allows to make a detailed study of the interstellar medium in a high redshift galaxy. The ISM in the low ionisation state and the kinematics of the absorption line components reveal a complex velocity field. The metallicity measured from different absorption lines is around 0.1 solar. Other GRB hosts at redshift beyond ˜3 have similar metallicities albeit with a large scatter in the metallicity distribution. X-shooter will allow us to determine metallicities of a larger number of GRB hosts beyond redshift 5, to probe the early chemical enrichment of the Universe and to study its evolution from redshift 2 to beyond 10.