... ROTATION CURVE: When studying spiral galaxies it is invariably found that the stellar rotational velocity in the disk remains constant, or "flat", with increasing distance away from the galactic center. ... The rotation speed of the stars in galaxies is found NOT to decrease with increasing distance from the galactic center (see emission lines in the spectrum), implying that the overall mass distribution of the galaxy is different from the light distribution. ...

... 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 .. ...