Gravitational Macrolensing And Quasar Spectra
Gravitational microlensing, i. e. lensing by stars in a foreground galaxy, can affect not only the radiation flux observed from quasars (Chang and Refsdal, 1979) but also the spectral line profiles (NemirofF, 1988; Schneider and Wambsganss, 1990). As a rule, in contrast to it, gravitational macrolensing, i. e. lensing by a whole galaxy or a cluster of galaxies, affects only the radiation flux; differences in image spectra arise mainly from source variability and travel time delays between images. However, if the source, the lens, and the observer are in motion relative to one another, then an additional shift in the source’s image spectrum occurs due to the aberration of light (Birkinshaw and Gull, 1983; Khmil, 1988 and references therein). Here we consider the special case of intrinsic motions in the source and study their influence on spectra of macroimages.
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