Eighteen candidates for emission line galaxies were discovered in a
narrow-band infrared survey that targeted the redshifts of damped Lyman-alpha
or metal lines in the spectra of quasars. The presence of emission lines is
inferred from the photometric magnitudes in narrow and broad band interference
filters, corresponding to H-alpha at redshifts of 0.89 (6 objects) and 2.4 (10
objects), and [OII] at a redshift of 2.3 (2 objects). Most of the candidates
are small resolved objects, compatible with galaxies at the redshifts of the
absorbers. Because a similar survey targeted at the redshifts of quasars
themselves uncovered only one emission-line galaxy in a larger volume, the
results imply substantial clustering of young galaxies or formation within
filaments or sheets whose locations are indicated by the redshifts of strong
absorption along the lines of sight to more distant quasars.Comment: 12 pages including 3 figures, accepted for publication in ApJ Let