A&A 386, 865-868 (2002)
Dusty haloes of galaxies at intermediate redshiftsP. Teerikorpi
Tuorla Observatory, 21500 Piikkiö, Finland
(Received 10 January 2002 / Accepted 20 February 2002 )
The presence and amount of dust in the halo matter producing narrow metal line absorption systems is still uncertain. We consider the parameter , summed over the detected aborption line system redshifts , and ask whether radio-loud quasars at z < 2 and with a large value of the parameter are redder in the B-V colour than those with a smaller . This is anticipated if the absorption lines originate in sites which contain "normal" dust causing selective extinction. The answer is positive, and a mean intrinsic reddening e0 per halo is consistent with 0.05, or about 0.2 B-mag extinction, roughly as expected.
Key words: quasars: absorption lines -- galaxies: haloes -- ISM: dust
© ESO 2002