The Evolution of the Global Star Formation History as Measured from the Hubble Deep Field

摘要

The Hubble Deep Field (HDF) is the deepest set of multicolor optical photometric observations ever undertaken, and it offers a valuable data set with which to study galaxy evolution. Combining the optical WFPC2 data with ground-based near-infrared photometry, we derive photometrically estimated redshifts for HDF galaxies with J < 23.5. We demonstrate that incorporating the near-infrared data reduces the uncertainty in the estimated redshifts by approximately 40/100 and is required to remove systematic uncertainties within the redshift range 1 < z < 2.