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1998) and Abraham et al. (1999a) have shown that the redshifting of UV wavelengths into the optical is not sufficient to explain the preponderance of irregular morphologies. Further confirmation that the rapid rise with redshift in the fraction of galaxies with irregular/peculiar morphologies is real, came from the Near Infrared Camera and Multi Object Spectrograph (NICMOS) observations. , 1999) have demonstrated that with very few (interesting by themselves) exceptions, the irregularities seen in the optical (WFPC2) image persist in the infrared image (Fig.

Supernovae at relatively high redshift are then monitored photometrically to construct their light curves. An image of the host galaxy is obtained at a later time (after a year or more), and subtracted to obtain an accurate measurement of the SN brightness. The Hubble Space Telescope has proved to be crucial especially for the highest-redshift 51 supernovae. There, the ability to resolve and pinpoint the SN location on the host (including in cases in which the SN was found close to the galactic nucleus) was essential for a correct determination of the SN magnitudes.

2003, in preparation; GO 7817) reobserved the field with NICMOS. , 2000), making SN 1997ff the farthest known supernova to date. , 2001, for a full description). The importance of detecting a SN Ia at such a high redshift cannot be overemphasized. 7, at z ∼ gravity would still have dominated over the cosmic repulsion, resulting in a decelerated expansion. Consequently, SNe Ia in the redshift range z ∼ 1–2 should appear brighter relative to SNe in a coasting universe. On the other hand, any effect that increases monotonically with redshift, as would be expected from dust extinction and simple evolutionary effects, would predict that the SNe Ia would be dimmer with increasing redshift.