1. Diffraction from 2d Lenses in the ISM
Dan Stinebring, John Matters, Dan Hemberger, T. Joseph Lazio*
Oberlin College, * Naval Research Lab
The parameters of the lenses shown below are the following. All widths are expressed in units in which the entire observer plane (not just the zoomed-in version) extends from –1 to +1 along each axis. The Gaussian has sx = sy = The filled ellipse has sx = 0.05 and sy = The shell-like lens has sx = 0.05, sy = and Dr =
1The secondary spectrum is the squared modulus of the 2d Fourier transform of the basic observable (flux density as a function of frequency and time).
Gaussian Lens
Elliptical Lens
Shell-like Lens
Figure Labeling. We use the following convention: columns are labeled 1 – 6 (left to right) and rows are labeled a – d (top to bottom). Odd numbered columns are depictions of the intensity modulation at the observer plane. Even numbered columns are horizontal cross-sectional cuts through the intensity pattern.