The Hawaii K-Band Galaxy Survey. III. Spectroscopy of K < 20 Galaxies
Abstract
We present spectra and multicolor (B, I, K) data for near-infrared (K) selected spatially complete magnitude limited (K < 20) galaxy samples from the Hawaii Survey. The redshift identification of the sample of 298 galaxies is substantially complete to a B magnitude of 26 and an I magnitude of 22.5, and identification of observed galaxies ranges from nearly 100% completeness at K < 18 to ~70% completeness at K = 19-20. We note that many of the unidentified objects appear to be red (I - K) objects which are flat in the optical and spectroscopically featureless. Strengths of spectral-line features and breaks are tabulated for the 262 galaxies with reasonably secure redshifts. The measured redshift is nearly all fall at z <~ 1, with the exception of a compact absorption- line object at z = 2.35. At K <= 18, the redshift distribution is well fitted by a model with no luminosity evolution, implying that from the K- band Hubble diagram, the Hubble constant can vary at most by 10% over the redshift range from z ~0.025 to 0.25, and that positive luminosity evolution at any significant level between z = 0 and z = 1 is ruled out. However, the evolution of both the emission-line strengths and the 4000 A break indicates that galaxies were undergoing significantly more star formation at z = 1 than at the present time.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- October 1994
- DOI:
- 10.1086/192080
- Bibcode:
- 1994ApJS...94..461S
- Keywords:
-
- Cosmology;
- Extremely High Frequencies;
- Galactic Evolution;
- Sky Surveys (Astronomy);
- Balmer Series;
- Hubble Diagram;
- Red Shift;
- Star Formation Rate;
- Stellar Luminosity;
- Astrophysics;
- COSMOLOGY: OBSERVATIONS;
- GALAXIES: DISTANCES AND REDSHIFTS;
- GALAXIES: EVOLUTION;
- INFRARED: GALAXIES;
- SURVEYS