A Serendipitous Search for Hy-Redshift Ly$Alpha$ Emission: A Case Study of Two Sources at $z\simeq 3$

Abstract

In the course of our on-going search for serendipitous high-redshift LyA emission in deep archival Keck spectra, we discovered two LyA emission line candidates in a moderate dispersion ($λ/{Δλ} +~ 1200$) spectrogram. Both lines have high equivalent width (EW_{obs}>= 450A), low velocity dispersions ($σ_v ~ 60 km/s), and deconvolved effective radii $r_e ~ 1.0 h_{50}^{-1}$ kpc. Their sizes and luminosities are suggestive of the primeval galaxy model of Lin & Murray (1992), based on the self-similar collapse of an isothermal sphere. We argue that the line emission is LyA, and it is stellar in origin. The sources are consistent with being primeval.