3 papers
astro-ph2007
Gravitational Lensing Statistics by Galaxy Clusters with Smoothness Parameter Depending on z
Monica Valencia, Leonardo Castaneda
Using the Eikonal approximation we study the effect of the smoothness parameter in the Dyer-Roeder equation. We calculate the optical depth for dark halos with NFW profile, for the…
astro-ph2007
Radiative Transfer in Special Relativity: Covariance
Mauricio Duque, Leonardo Castaneda, Carlos Duque
The purpose is to introduce in a clear and direct way the students of undergraduate courses in physics and/or astronomy to the subject of radiative transfer. A pedagogical revision…
astro-ph2004
Kinematics in Hickson Compact Group 90
Leonardo Castaneda, Michael Hilker
Using long-slit spectra observed at the VLT (ESO, Paranal) in May 2002, we studied the stellar kinematics in the core of the Hickson Compact Group 90. The line of sight velocity di…