Esther M. Hu

High-z Lyα Emitters. I. A Blank-Field Search for Objects near Redshift z = 3.4 in and around the Hubble Deep Field and the Hawaii Deep Field SSA 22

We present deep narrowband (λ = 5390 A, Δλ = 77 A) and multicolor observations of the Hubble Deep Field and the Hawaii Deep Field SSA 22 obtained with the LRIS instrument at the 10 m Keck II Telescope. It is shown that there is a substantial population of galaxies at z ~ 3.4 that can be selected by Lyα emission. Comparison with color-selected samples shows that the samples selected with these different criteria have substantial, but not complete, overlap and that there is a comparable surface density in the two selected populations. The emission-line–selected samples include objects with strong Lyα, and which are significant contributers to the integrated star formation at these epochs. For a Salpeter initial mass function, we estimate a minimum star formation rate of 0.01 M⊙ Mpc-3 yr-1 at z = 3.4 for H0 = 65 km s-1 Mpc-1 and q0 = 0.5 in the Lyα-selected objects, though the value could be substantially higher if there is significant extinction.We present deep narrowband (j \ 5390 *j \ 77 and multicolor observations of the Hubble Ae ,A e ) Deep Field and the Hawaii Deep Field SSA 22 obtained with the LRIS instrument at the 10 m Keck II Telescope. It is shown that there is a substantial population of galaxies at z D 3.4 that can be selected by Lya emission. Comparison with color-selected samples shows that the samples selected with these di†er- ent criteria have substantial, but not complete, overlap and that there is a comparable surface density in the two selected populations. The emission-lineEselected samples include objects with strong Lya, and which are signi-cant contributers to the integrated star formation at these epochs. For a Salpeter initial mass function, we estimate a minimum star formation rate of 0.01 Mpc~3 yr~1 at z \ 3.4 for M _ H 0 \ 65 km s~1 Mpc~1 and in the Lya-selected objects, though the value could be substantially q 0 \ 0.5 higher if there is signi-cant extinction.

THE TEAM KECK TREASURY REDSHIFT SURVEY OF THE GOODS-NORTH FIELD

We report the results of an extensive imaging and spectroscopic survey in the Great Observatories Origins Deep Survey (GOODS)-North field completed using DEIMOS on the Keck II telescope. Observations of 2018 targets in a magnitude-limited sample of 2911 objects to RAB = 24.4 yield secure redshifts for a sample of 1440 galaxies and active galactic nuclei (AGNs) plus 96 stars. In addition to redshifts and associated quality assessments, our catalog also includes photometric and astrometric measurements for all targets detected in our R-band imaging survey of the GOODS-North region. We investigate various sources of incompleteness and find the redshift catalog to be 53% complete at its limiting magnitude. The median redshift of z = 0.65 is lower than in similar deep surveys because we did not select against low-redshift targets. Comparison with other redshift surveys in the same field, including a complementary Hawaii-led DEIMOS survey, establishes that our velocity uncertainties are as low as σ ≈ 40 km s-1 for red galaxies and that our redshift confidence assessments are accurate. The distributions of rest-frame magnitudes and colors among the sample agree well with model predictions out to and beyond z = 1. We will release all survey data, including extracted one-dimensional and sky-subtracted two-dimensional spectra, thus providing a sizable and homogeneous database for the GOODS-North field, which will enable studies of large-scale structure, spectral indices, internal galaxy kinematics, and the predictive capabilities of photometric redshifts.

The Distribution of column densities and b values in the Lyman-alpha forest

We describe the properties of the Ly

An atlas of z = 5.7 and z = 6.5 Lyα emitters

\alpha

The Hawaii K-band galaxy survey. 1: Deep K-band imaging

forest in the column density range

The Redshift evolution of the Ly-alpha forest

\nhi \geq 2\times10^{12}

Two extremely red galaxies

cm

The Hawaii K-Band Galaxy Survey. II. Bright K-Band Imaging

^{-2}

Detection of Lyman-α-emitting galaxies at redshift 4.55

based on 1056 lines in the wavelength range 4300--5100\AA measured in extremely high S/N,

An extremely luminous galaxy at z=5.74

R=36,000