Astrophysics of Gaseous Nebulae and Active Galactic Nuclei (University Science Books: California
- P. Madau, L. Pozzetti, M. Dickinson
We present a new spectrum extraction technique which employs optimal weights for the spectral extraction, deblends the overlapping spectra, determines the precise sky background, and takes into account correlations between errors correctly for STIS slitless observations. We obtained roughly 250 optimally extracted spectra in a deep STIS field as well as selfconfirming redshift measurements for these objects, including a galaxy at z = 6.68. In addition, we identified five isolated emission-line objects in the dispersed image that were not accounted for by objects detected in the direct image. Assuming that these are Lyα emission line galaxies at high redshifts and adopting a simple δ-function galaxy luminosity function for these objects, we find, based on a likelihood analysis, that Lyα emission line galaxies at 〈z〉 ≈ 4.69 may contribute at most 15% of the star formation rate density measured in Lyman break galaxies at z ≈ 4.