Optical-turbulence and wind profiles at San Pedro mártir with G-SCIDAR
Por:
Avila R., Sánchez L.J., Ibañez F., Vernin J., Masciadri E., Azouit M., Agabi A., Cuevas S.
Publicada:
1 ene 2007
Resumen:
We present the results of monitoring optical-turbulence profiles at the Observatorio Astronómico Nacional de San Pedro Mártir, Mexico, during 11 nights in March and April 1997 and 16 nights in May 2000. The speed of turbulent layers was also monitored, but only for the 2000 period. 6414 turbulence profiles and 3016 wind profiles were measured and statistically analyzed. The main results concerning the turbulence profiles are: (i) the seeing produced by the turbulence in the first 1.2 km at the 1.5-m and the 2.1-m telescopes, not including turbulence inside the domes, has median values of 0.?63 and 0.?44, respectively. (ii) The median values of the seeing produced above 1.2 km and in the whole atmosphere are 0.?38 and 0.?71. (iii) The isoplanatic angle for full correction adaptive optics has a median value of 1.?87. (iv) 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 hours, respectively. (v) The isoplanatic-angle decorrelation-time is estimated to be equal to 2 hours. The results concerning the wind profiles are: (vi) No significant correlation is found between the turbulence intensity (CN 2) and the speed of the turbulent layers V. (vii) Layers in the first 5 km and higher up than 16 km, above sea level, are similarly slow, with median speeds of 8.6 and 9.6 m s-1. (viii) Between 9 and 16 km, where the jet stream takes place in some of the nights, the median wind speed is 26.0 m s-1. (ix) From the simultaneous measurements of CN 2(h) and V(h), we compute the temporal coherence of the turbulence layer by layer. The results obtained here places San Pedro Mártir among the best suited sites for installing next generation optical telescopes.
Filiaciones:
Avila R.:
Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia, Mexico
Sánchez L.J.:
Instituto de Astronomía, Universidad Nacional Autónoma de México, México, 04510 D. F., Mexico
Ibañez F.:
Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia, Mexico
Vernin J.:
U.M.R. 6525 Astrophysique, UNSA, CNRS, France
Masciadri E.:
Instituto de Astronomía, Universidad Nacional Autónoma de México, México, 04510 D. F., Mexico
INAF, Osservatorio Astrofisico di Arcetri, Firenze, Italy
Azouit M.:
Instituto de Astronomía, Universidad Nacional Autónoma de México, México, 04510 D. F., Mexico
U.M.R. 6525 Astrophysique, UNSA, CNRS, France
Agabi A.:
U.M.R. 6525 Astrophysique, UNSA, CNRS, France
Cuevas S.:
Instituto de Astronomía, Universidad Nacional Autónoma de México, México, 04510 D. F., Mexico
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