Open AccessWeyl focusing effects on image magnification due to randomly distributed isothermal objects
Author(s) -
Hamana Takashi
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02170.x
Subject(s) - physics , astrophysics , gravitational lens , galaxy , redshift , universe , weak gravitational lensing , gravitational lensing formalism , strong gravitational lensing , magnification , gravitation , lens (geology) , dark matter , focus (optics) , astronomy , optics
Weyl focusing effects on image magnifications are investigated by using the multiple gravitational lens theory. We focus on the gravitational lensing effects that are a result of small‐scale virialized objects, such as galaxies and clusters of galaxies. We consider a simple model of an inhomogeneous universe. The matter distribution in the universe is modelled by randomly distributed isothermal objects. We found that, for the majority of the random lines of sight, the Weyl focusing has no significant effect and the image magnification of a point‐like source within a redshift of 5 is dominated by Ricci focusing.