Upper Limits to Balmer-Line Emission in Three Z approximately 2 Damped Lyman- alpha Systems
Abstract
We have searched for Hα and Hβ emission in the high-z damped Lyα systems toward the quasars PHL 957, Q0528-250, and Q0836+ 113. We failed to detect the Balmer lines with 2 σ upper limits on Hα of around 2 x 10^-16^ ergs cm^2^ s^-1^, with similar limits on [O III] and Hβ for the first two systems. The results suggest that the weak or undetectable Lyα emission in these systems is not simply a consequence of dust destruction, but reflects a relatively low star-formation rate. For the Lyα emitting companion to PKL 957 we report an Hα flux of 3.6 +/- 1.5 x 10^-16^ ergs cm^2^ s^-1^, implying f(Lyα)/f(Hα) >= 1.6 and suggesting that Lyα cannot be reduced by more than a factor of 10 in this object.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1993
- DOI:
- 10.1086/187125
- Bibcode:
- 1993ApJ...419L..13H
- Keywords:
-
- COSMOLOGY: OBSERVATIONS;
- GALAXIES: QUASARS: ABSORPTION LINES;
- GALAXIES: QUASARS: INDIVIDUAL ALPHANUMERIC: PHL 957;
- GALAXIES: QUASARS: INDIVIDUAL ALPHANUMERIC: 0528-250;
- GALAXIES: QUASARS: INDIVIDUAL ALPHANUMERIC: 0836+113