Simple Waves Reference: Landau & Lifshitz, Fluid Mechanics 1 Nonlinear waves 1.1 Small amplitude waves When we considered sound waves we considered small amplitude perturbations to the fluid equations. In 1D 2 1 2 ------------ ­ ----- ------------ = 0 2 x 2 cs t 2 (1) Astrophysical Gas Dynamics: Simple Waves 1/33 The solution to this equation, of course, is: = f 1 x ­ c s t + f 2 x + c s t (2) where f 1 and f 2 are arbitrary functions. ... Astrophysical Gas Dynamics: Simple Waves 14/33 NB. ...

... Printed in U.S.A. THE STELLAR DISK THICKNESS OF LOW SURFACE BRIGHTNESS GALAXIES D. Bizyaev 1,2,3 and S. Kajsin 4 Received 2003 October 23; accepted 2004 June 9 ABSTRACT We present surface photometry results for a sample of 11 edge-on galaxies observed with the 6 m telescope at the Special Astrophysical Observatory, Russia. ... We find from a comparison of photometric scales that the stellar disks of LSB galaxies are thinner than those of high surface brightness ( HSB) galaxies. ... UGC 11301 .. ...