Weak gravitational lensing of distant galaxies
May 20, 199131 pages
Published in:
- Astrophys.J. 388 (1992) 272
DOI:
Report number:
- CITA-91-14
View in:
Citations per year
Abstract: (ADS)
The two-point statistics of the gravitationally induced ellipticities of distant galaxy images which provide a direct probe of the mass fluctuation spectrum P(k) is analyzed. The relation between the ellipticity pattern of the background galaxies and the projected density of foreground matter is explored. This yields both useful statistical correlations and also an approximate method for directly imaging foreground mass concentrations. Angular power spectra are calculated using the analogue of Limber's equation in the Fourier domain, as well as angular correlation functions. It is found that there are some characteristic features of the ellipticity correlations that appear most clearly in the Fourier representation. The analysis is valid for arbitrary evolution of P(k) and for an arbitrary distance distribution for the galaxies. It is shown that the size of the effect on very large scales is tightly constrained by microwave anisotropy limits, but that the density fluctuations inferred from observed peculiar motions suggest interestingly large effects at angular scales below about a degree.References(6)
Figures(0)