Astrophysical Applications of Gravitational Micro-Lensing /
Abstract
Gravitational micro-lensing due to stars in the deflecting galaxy influences the brightness and the spectra of the macro-images. Furthermore changes in the spectra due to micro-lensing may give informations on the quasar structure. From high amplification events the brightness profile of the source may be obtained. The time scale of the high amplification event is proportional to the source radius and inverse proportional to the transversal velocity. Due to the large brightness gradient by a high amplification event, a "parallax-effect" occurs, from which the transversal velocity may be obtained, and thereby the source radius (R = ΔtmVT). The authors roughly estimate 0.3 high amplication events per year for all gravitationally lensed quasars.
- Publication:
-
Observational Cosmology
- Pub Date:
- 1987
- Bibcode:
- 1987IAUS..124..767K