Starformation%20at%20z~20%20?

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NICMOS Spectra of z6 Quasars I ESA Press Release
HEIC0306

• Observations
• at z6, the Fe II bands are shifted to ??1.5 to
  1.9 ?m
• NICMOS has unique capability to observe spectra
  in this band
• QSOs at H19 can easily reached with NICMOS
  grism G141
• Technically challenging since pixel-response
  introduces features similar to such a broad band.
  Characterization of this effect and software to
  correct for it (NICMOSlook) has been developed at
  ST-ECF.

• Results
• High Fe II / Mg II ratios detected in all
  spectra, no evolution from local QSOs
• at z6, age of universe lt 900Myrs
• implies that Fe was either created in Population
  III stars or first generation of Population II
  stars.

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NICMOS Spectra of z6 Quasars II
? Wolfram Freudling and European Space Agency
blackNICMOS spectrared local QSO template
Fe II / Mg II flux ratios for QSOs at z5 to 6.28
Freudling, Corbin, Korista 2003 ApJ 587, L67
Solar ratio