A serendipitous search for hy-redshift Lyα emission:: A case study of two sources at z ≃ 3
HY-REDSHIFT UNIVERSE: GALAXY FORMATION AND EVOLUTION AT HIGH REDSHIFT 193 (1999) 521-524
Optical spectroscopy of two overlapping, flux-density-limited samples of radio sources in the North Ecliptic Cap, selected at 38 and 151 MHz
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 308:4 (1999) 1096-1116
The deepest spectrum of the universe? Constraints on the Lyman continuum background at high redshift
HY-REDSHIFT UNIVERSE: GALAXY FORMATION AND EVOLUTION AT HIGH REDSHIFT 193 (1999) 262-266
A z = 5.34 galaxy pair in the Hubble Deep Field
Astronomical Journal 116:6 (1998) 2617-2623
Abstract:
We present spectrograms of the faint V-drop (V606 = 28.1, I814 = 25.6) galaxy pair HDF 3-951.1 and HDF 3-951.2 obtained at the Keck II Telescope. In a recent study, Fernández-Soto, Lanzetta, & Yahil derive a photometric redshift of zph = 5.28+0.34-0.41 (2 σ) for these galaxies; our integrated spectrograms show a large and abrupt discontinuity near 7710 ± 5 Å. This break is almost certainly due to the Lyα forest because its amplitude (1 - fshortv/flongv > 0.87, 95% confidence limit) exceeds any discontinuities observed in stellar or galactic rest-frame optical spectra. The resulting absorption break redshift is z = 5.34 ± 0.01. Optical/near-IR photometry from the HDF yields an exceptionally red (V606 - I814) color, consistent with this large break. A more accurate measure of the continuum depression blueward of Lyα utilizing the imaging photometry yields DA = 0.88. The system as a whole is slightly brighter than L*1500 relative to the z ∼ 3 Lyman break population, and the total star formation rate inferred from the UV continuum is ≈22 h-250 M⊙ yr-1 (q0 = 0.5) assuming the absence of dust extinction. The two individual galaxies are quite small (size scales ≲ 1 h-150 kpc). Thus these galaxies superficially resemble the "building blocks" of Pascarelle and coworkers; if they comprise a gravitationally bound system, the pair will likely merge in a timescale ∼100 Myr.Keck spectroscopy and nicmos photometry of a redshift z = 5.60 galaxy
Astrophysical Journal 505:2 PART II (1998)