A Narrow-Band IR Survey for Hα -Emitting Galaxies at z>= 1
Abstract
We present the preliminary results of a narrow-band IR survey of QSO and metal absorption-line fields for redshifted Hα /[NII] emission from starforming galaxies at z>= 1. As we reported in BAAS 188.21.02 this survey has already lead to the discovery of several possible clusters. To date, in fields targetted for objects at z>2, we have observed more than 8 sqaure arcminutes using 1% filters in the Near IR Camera on the Keck 10m telescope. The observations reach a limiting magnitude of K=22, and would detect a limiting Hα flux of 3x 10(-17) ergs/s/cm(2) (H0=50, q0=0.5). In these fields we have detected 10--12 Hα candidates, down to an inferred continuum luminosity of L* or below. In all but one object, the detections have been in fields containing metal-absorption line systems. The detected objects have shown compact, but resolved morphologies, not exceeding FWHM=1({') '} (8kpc). The inferred Star Formation Rate of objects is typically 20 Msun/year, but some objects exceed 100 Msun/year. Spectroscopic followup with the Low Resolution Imaging Spectrometer has confirmed the redshift of our first detection. The high surface density of detections ( ~ 1.5/sq.arcminute) and high SFR suggests clustering in fields containing metal-absorption line systems. In fields targetted to z ~ 1, we have surveyed 50 square arcmintues down to limiting magnitude of K=19, using the UCLA 2-channel IR Camera on the Shane 3m telescope at Lick Observatory. To date, few emission line galaxies have been detected. In some fields a 2--3sigma excess of galaxies is observed.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1996
- Bibcode:
- 1996AAS...18911204T