The pattern speeds of M51, M83 and NGC 6946 using carbon monoxide and the Tremaine-Weinberg method, and, Novel techniques for the characterization of optical turbulence in the surface layer

In spiral galaxies where the molecular phase dominates the interstellar medium, the molecular gas as traced by CO emission will approximately obey the continuity equation on orbital timescales. The Tremaine-Weinberg method can then be used to determine the pattern speed of such galaxies. We have applied the method to single-dish CO maps of three nearby spirals, M51, M83 and NGC 6946 to obtain estimates of their pattern speeds: 38 +/- 7 km/s/kpc, 45 +/- 8 km/s/kpc and 39 +/- 8 km/s/kpc, respectively, and we compare these results to previous measurements. We also analyze the major sources of systematic errors in applying the Tremaine-Weinberg method to maps of CO emission.; Characterization the atmospheric surface layer is an important and often overlooked step in site selection for small telescopes. Turbulence in the surface layer can contribute half or more of the total atmospheric image degradation encountered at a typical astronomical site. The overall image quality of the site feeds back into the design of both the optical system and instruments of telescopes in significant ways, both scientific and financial. Existing methods of characterizing turbulence in the surface layer measure non-optical quantities and rely heavily on turbulence theory that is unlikely to apply in surface layer conditions at astronomical sites. Therefore, it was undertaken to develop new optical methods to focus specifically on characterizing turbulence in the first thirty meters of the surface layer.; The Two Source Differential Image Motion Monitor (2SDIMM) measures the apparent separation of a pair of transmitters suspended from the top of a tower, extending the traditional Differential Image Motion Monitor concept to surface layer studies. The Structure Function Monitor (SFM) adapts the Gerchberg-Saxton phase retrieval algorithm to the recovery of the phase of the incoming wavefront from an artifical source across the aperture of a small telescope. From the wavefront phase, all relevant atmospheric turbulence parameters can be obtained on all spatial scales available to the aperture.