We report the detection of a z _ { abs } =0.3654 associated absorption-line system in the UV spectrum of the CSS quasar 3C48 .
The absorbing material is blue shifted with respect to the quasar emission-line redshift , z _ { em } =0.3700 , suggesting an outflow velocity of \sim 1000 km s ^ { -1 } .
We detect absorption lines over a range of ionization states from Ly \beta , Ly \gamma , C iv , N iv , S vi to O vi and possibly O iv and Ne viii .
The kinematical properties of the absorption-line system are similar to the blue-shifted emission line gas seen in [ O iii ] \lambda 5007 ( Chatzichristou , Vanderriest & Jaffe 1999 ) , which is believed to have interacted with the radio jet .
We study the properties of the absorbing material using CLOUDY and find that photoionization models with Solar abundance ratios ( with overall metallicity in the range 0.1 \leq Z/Z _ { \odot } \leq 1.3 ) are enough to explain the observed column densities of all the species except Ne viii , detection of which requires confirmation .
Since the cooling and recombination time for the gas is \sim 10 ^ { 5 } yr , the consistency with the photoionization models suggests that any possible interaction of absorbing material with the jet must have taken place before \sim 10 ^ { 5 } yr .
The abundance ratio of nitrogen to carbon is close to Solar values , unlike in the case of most quasars , especially at high-redshifts , which have super-Solar values .
We observed 3C48 with the Giant Metrewave Radio Telescope ( GMRT ) to search for redshifted 21cm H i absorption .
However , we did not detect any significant feature in our spectra and estimate the 3 \sigma upper limit to the optical depth to be in the range 0.001 to 0.003 .
However , due to the diffuse nature of the radio source , optical depths as high as 0.1 towards individual knots or compact components can not be ruled out .