L. J. Sánchez

Atmospheric turbulence and wind profiles monitoring with generalized scidar

We present a method for simultaneous measurement of the vertical distribution of the optical turbulence strength C N(h) and wind velocity V (h) in the Earth’s atmosphere, based on an analysis of spatio-temporal correlations of stellar scintillation images obtained with generalized scidar. A statistical comparison of V (h) obtained with this method and instrumented balloons supports the use of this method. The algorithm used allows for the identification of dome seeing, which can be subtracted from C N(h), to obtain a turbulence profile free of dome contribution. Examples of simultaneous C N(h) and V (h) monitorings are presented.

Generalized SCIDAR Measurements at San Pedro Martir. I. Turbulence Profile Statistics

We present the results of monitoring optical-turbulence profiles at San Pedro Martir, Mexico, during 11 nights in 1997 March and April, and 16 nights in 2000 May. The data were collected using the generalized scintillation detection and ranging (SCIDAR) technique from Nice University at the 1.5 and 2.1 m telescopes. A total of 6414 turbulence profiles were measured and statistically analyzed. The principal results are as follows: the seeing produced by the turbulence in the first 1.2 km at the 1.5 m and 2.1 m telescopes, not including turbulence inside the domes, have median values of 063 ± 001 and 044 ± 002, respectively. The dome seeing at those telescopes have median values of 064 ± 001 and 031 ± 002. The median values of the seeing produced above 1.2 km and in the whole atmosphere are 039 ± 001 and 071 ± 001. The isoplanatic angle for full-correction adaptive optics has a median value of 187 ± 004. The decorrelation time (defined as the time lag for which the temporal correlation drops to 50%) of the turbulence strength at altitudes below and above 16 km above sea level is approximately equal to 2 and 0.5 hr, respectively. The isoplanatic-angle decorrelation time is estimated to be equal to 2 hr. The turbulence above ~8 km remained notably calm during nine consecutive nights, which is encouraging for adaptive optics observations at the site. The results obtained here places San Pedro Martir among the best suited sites for installing next-generation optical telescopes.

The Faber-Jackson relation for early-type galaxies: dependence on the magnitude range

We take a sample of early-type galaxies from the Sloan Digital Sky Survey (SDSS-DR7,

Turbulence and wind profiling with generalized scidar at Cerro Pachon

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Influence of scintillations on the performance of adaptive astronomical systems with Hartmann-like wavefront sensors

90 000 galaxies) spanning a range of approximately 7

Co-phasing of segmented mirror telescopes with curvature sensing

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Curvature equation for a segmented telescope

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Wavefront outer scale and seeing measurements at San Pedro Mártir Observatory

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Efficiency of the Hartmann test with different subpupil forms for the measurement of turbulence-induced phase distortions.

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The intrinsic dispersion in the Faber-Jackson relation for early-type galaxies as function of the mass and redshift

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