Interstellar lines in spectra of extragalactic sources. III. Markarian 509, Arakelian 120 and 3C 273.
York, D. G.; Cowie, L. L.; Morton, D. C.; Wu, C. C.; Ratcliff, S.; Blades, J.
United States, Australia
Abstract
Spectra of two Seyfert galaxies, Mrk 509 and Akn 120, show galactic interstellar absorption lines of S II, Si II, and Fe II, while Si IV absorption is seen in the quasar 3C 273. The lines appear at LSR velocity of less than 100 km/s and probably lie within 3 kpc of the galactic disk. Extragalactic absorption lines are found in the spectrum of Mrk 509, with two redshift systems at z = 0.033 and 0.034 identified to have Ly-alpha and both members of the C IV doublet. In one of these systems, (D/H) is less than 0.0001. No metal-poor absorption systems are seen in the narrow redshift ranges sampled in each object, whereas one or two might have been expected.