Gonzalo Diaz
Connecting star formation and its products in the early universe.
The production of metals by the first stars in the universe is closely related to the emission of Lyman continuum photons responsible for the cosmic reionization of hydrogen which could have started at z > 15 and continued until z ~ 6. Recent observation of high resolution spectroscopy had revealed the presence of metals in the most distant IGM trough the detection of absorption systems in spectra of background QSOs. The most common and easiest to recognize is the CIV doublet. Even though these absorption systems are associated with star forming galaxies, whether this enrichment of the IGM occurs from super galactic winds or the dynamical disruption of small mass galaxies is still a matter of debate.
We will use FORS2 multi-object spectroscopy (VLT) to measure the redshift of two candidate z > 5.5 galaxies which are close enough to the line of sight towards the QSO SDSS J1030+0524 to be responsible of the CIV absorption detected in the spectrum of the QSO. If they could have produced the absorption or not will support different scenarios and provide constraints on the physical extend of the enriched, ionizing outflow of the galaxies.
Furthermore, cosmic reionization is expect to be a patchy process. A highly variable ionization state is detected at 5 < z < 6 but there is no agreement in whether or not the largest overdensities should be the first or last to be permanently ionized. Then, we will use the Supreme Cam/Subaru to image field with highly ionized absorption line systems at z ~ 5-6. Studying the density of galaxies at z ~ 5-6 will help us to discriminate between theoretical models that predict regions of ionized IGM should correspond an under/over-density of galaxies.
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