Detailed ultraviolet observations of the quasar 3C 273 with the IUE.
Tarenghi, M.; Perola, G. C.; Boksenberg, A.; Penston, M. V.; Snijders, M. A. J.; Elvius, A.; Ulrich, M. H.; Wilson, R.; Lindegren, L.; Perryman, M. A. C.; Gondhalekar, P. M.; Pettini, M.; Gabriel, A.; Longair, M. S.; Carswell, R.; Bromage, G.; Lind, J.; Rees, M.; Sciama, D.; Tanzi, E.
Switzerland, United Kingdom, Sweden
Abstract
The paper analyzes the nine spectra of the quasar 3C 273 obtained with the International Ultraviolet Explorer in order to combine them and to obtain a high signal-to-noise spectrum between 1100 and 3300 A. An analysis was then made of the emission line intensity ratios and of the continuous energy distribution; evidence was found for thermal contribution to the ultraviolet continuum. The ultraviolet spectrum of 3C 273 shows eight absorption lines at zero redshift due to the intervening material of our galaxy; the C IV lambda absorption is much stronger in the spectrum of 3C 273 than in the spectra of halo stars, showing that a hot gaseous component exists in the outer regions of the halo of the galaxy.