A Search for Extended Line Emission from BALQSOs

Abstract

We have obtained HST NICMOS snapshot images of ten BALQSOs and four radio-quiet non-BALQSOs to search for extended narrow-line regions. For each object we obtained an image in the F160W filter and a narrow-band image in either H-alpha, H-beta, or [O ii]. We find no detections of extended narrow-line emission in the sample. We generate simulated images of QSOs with extended narrow-line regions to place limits on the amount of flux that may be present, and we conclude that BALQSOs cannot be more than several times brighter in extended emission than typical type 2 AGN. Spatially unresolved H-alpha emission is detected in all nine objects observed in this line, which we attribute to broad H-alpha emission. The five detected BALQSOs have derived H-alpha equivalent widths that are larger than those of the four non-BALQSOs by a factor of around 2 on average. This may point to an intrinsic difference between the rest-frame optical spectral properties of BALQSOs and non-BALQSOs.