Detalles de publicación
PP 024037
Integral field spectroscopy supports atmospheric optics to reveal the finite outer scale of the turbulence
(1) IAC, (2) Departamento de Astrofísica, ULL
Context. The spatial coherence wavefront outer scale (L0) characterizes the size of the largest turbulence eddies in Earth’s atmosphere,
determining low spatial frequency perturbations in the wavefront of the light captured by ground-based telescopes. Advances in
adaptive optics (AO) techniques designed to compensate for atmospheric turbulence emphasize the crucial role of this parameter for
the next generation of large telescopes.
Aims. The motivation of this work is to introduce a novel technique for estimating L0 from seeing-limited integral field spectroscopic
(IFS) data. This approach is based on the impact of a finite L0 on the light collected by the pupil entrance of a ground-based telescope.
Methods. We take advantage of the homogeneity of IFS observations to generate band filter images spanning a wide wavelength
range, enabling the assessment of image quality (IQ) at the telescope’s focal plane. Comparing the measured wavelength-dependent
IQ variation with predictions derived from a first-order analytical approach based on turbulence statistics simplifications using the von
Kármán model provides valuable insights into the prevailing L0 parameter during the observations.We applied the proposed technique
to observations from the Multi-Unit Spectroscopic Explorer (MUSE) in the wide-field mode obtained at the Paranal Observatory.
Results. Our analysis successfully validates the first-order analytical expression, which combines the seeing (ϵ0) and the L0 parameters,
to predict the IQ variations with the wavelength in ground-based astronomical data. However, we observed some discrepancies
between the measured and predictions of the IQ that are analyzed in terms of uncertainties in the estimated ϵ0 and dome-induced
turbulence contributions.
Conclusions. This work constitutes the empirical validation of the analytical expression for estimating IQ at the focal plane of groundbased
telescopes under specific ϵ0 and finite L0 conditions. Additionally, we provide a simple methodology to characterize the L0 and
dome-seeing (ϵdome) as by-products of IFS observations routinely conducted at major ground-based astronomical observatories.
determining low spatial frequency perturbations in the wavefront of the light captured by ground-based telescopes. Advances in
adaptive optics (AO) techniques designed to compensate for atmospheric turbulence emphasize the crucial role of this parameter for
the next generation of large telescopes.
Aims. The motivation of this work is to introduce a novel technique for estimating L0 from seeing-limited integral field spectroscopic
(IFS) data. This approach is based on the impact of a finite L0 on the light collected by the pupil entrance of a ground-based telescope.
Methods. We take advantage of the homogeneity of IFS observations to generate band filter images spanning a wide wavelength
range, enabling the assessment of image quality (IQ) at the telescope’s focal plane. Comparing the measured wavelength-dependent
IQ variation with predictions derived from a first-order analytical approach based on turbulence statistics simplifications using the von
Kármán model provides valuable insights into the prevailing L0 parameter during the observations.We applied the proposed technique
to observations from the Multi-Unit Spectroscopic Explorer (MUSE) in the wide-field mode obtained at the Paranal Observatory.
Results. Our analysis successfully validates the first-order analytical expression, which combines the seeing (ϵ0) and the L0 parameters,
to predict the IQ variations with the wavelength in ground-based astronomical data. However, we observed some discrepancies
between the measured and predictions of the IQ that are analyzed in terms of uncertainties in the estimated ϵ0 and dome-induced
turbulence contributions.
Conclusions. This work constitutes the empirical validation of the analytical expression for estimating IQ at the focal plane of groundbased
telescopes under specific ϵ0 and finite L0 conditions. Additionally, we provide a simple methodology to characterize the L0 and
dome-seeing (ϵdome) as by-products of IFS observations routinely conducted at major ground-based astronomical observatories.