The Low-Redshift Lyman Alpha Forest toward 3C 273

We present an analysis of the Lyα forest towards 3C 273 from the Space Telescope Imaging Spectrograph at ∼7 km s−1 resolution, along with reprocessed data from the Far Ultraviolet Spectroscopic Explorer. The high ultraviolet flux of 3C 273 allows us to probe the weak, low-z absorbers. The main sample consists of 21 H i absorbers that we could discriminate to a sensitivity of ${\mathrm {log}}\, N_{...