TY - JOUR
T1 - A study of NIR atmospheric properties at Paranal Observatory (Research Note)
AU - Lombardi, G.
AU - Mason, E.
AU - Lidman, C.
AU - Jaunsen, A. O.
AU - Smette, A.
PY - 2011
Y1 - 2011
N2 - Aims: In order to maximize the scientific return of the telescopes located at the Paranal Observatory, we analyse the properties of the atmosphere above Paranal in the near-infrared (NIR). Methods. We estimate atmospheric extinction in the spectral range 1.10-2.30 μm (J, Js, H, and Ks) using standard stars that were observed during photometric and clear nights with ISAAC on the Very Large Telescope UT1 between 2000 and 2004. We have built a database consisting of hundreds of observations, which allows us to examine how extinction varies with airmass and the column density of water vapour. In addition, we use theoretical models of the atmosphere to estimate Rayleigh scattering and molecular absorption in order to quantify their fractional contribution to the total extinction in each filter. Finally, we have observed 8 bright red standard stars to evaluate filter color terms. Results. We find that extinction coefficients are < 0.1 mag airmass-1 in all the considered bands. The extinction coefficient in the J-band strongly depends on the column density of water vapour. Molecular absorption dominates the extinction in J, H and Ks, while Rayleigh scattering contributes most to the extinction in Js. We have found negligible color terms for J, H and Ks and a non-negligible color term for Js.
AB - Aims: In order to maximize the scientific return of the telescopes located at the Paranal Observatory, we analyse the properties of the atmosphere above Paranal in the near-infrared (NIR). Methods. We estimate atmospheric extinction in the spectral range 1.10-2.30 μm (J, Js, H, and Ks) using standard stars that were observed during photometric and clear nights with ISAAC on the Very Large Telescope UT1 between 2000 and 2004. We have built a database consisting of hundreds of observations, which allows us to examine how extinction varies with airmass and the column density of water vapour. In addition, we use theoretical models of the atmosphere to estimate Rayleigh scattering and molecular absorption in order to quantify their fractional contribution to the total extinction in each filter. Finally, we have observed 8 bright red standard stars to evaluate filter color terms. Results. We find that extinction coefficients are < 0.1 mag airmass-1 in all the considered bands. The extinction coefficient in the J-band strongly depends on the column density of water vapour. Molecular absorption dominates the extinction in J, H and Ks, while Rayleigh scattering contributes most to the extinction in Js. We have found negligible color terms for J, H and Ks and a non-negligible color term for Js.
KW - atmospheric effects
KW - Site testing
UR - http://www.scopus.com/inward/record.url?scp=79952179110&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201016404
DO - 10.1051/0004-6361/201016404
M3 - Article
AN - SCOPUS:79952179110
SN - 0004-6361
VL - 528
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A43
ER -