English
Related papers

Related papers: Ground Layer Adaptive Optics: PSF effects on ELT s…

200 papers

This project is focused on evaluating the slowly-varying ground layer seeing component at the optical telescopes of ARIES. To achieve this, we assembled the instrument, consisting of a filter wheel, a CCD camera, and a tip-tilt enabled…

Instrumentation and Methods for Astrophysics · Physics 2024-01-22 Purvi Udhwani , Amitesh Omar , Krishna Reddy

The advent of Extremely Large Telescopes ELTs, ground-based optical or infrared observatories with primary mirrors exceeding 20 m heralds a transformative epoch in observational astronomy. This article examines the dawn of this new era and…

Popular Physics · Physics 2026-05-22 Priya Hasan

We show that the errors due to atmospheric refraction are present in the magnitudes determined with the Difference Images Analysis method. In case of single, unblended stars the size of the effect agrees with the theoretical prediction. But…

Astrophysics · Physics 2007-05-23 A. Kruszewski , I. Semeniuk

The complete 10-year survey from the Large Synoptic Survey Telescope (LSST) will image $\sim$ 20,000 square degrees of sky in six filter bands every few nights, bringing the final survey depth to $r\sim27.5$, with over 4 billion well…

Here we describe a simple, efficient, and most importantly fully operational point-spread-function(PSF)-reconstruction approach for laser-assisted ground layer adaptive optics (GLAO) in the frame of the Multi Unit Spectroscopic Explorer…

Instrumentation and Methods for Astrophysics · Physics 2020-04-08 Thierry Fusco , R. Bacon , S. Kamann , S. Conseil , Benoit Neichel , Carlos Correia , Olivier Beltramo-Martin , Joel Vernet , Johann Kolb , Pierre-Yves Madec

Light scattering and aberrations limit optical microscopy in biological tissue, which motivates the development of adaptive optics techniques. Here, we develop a method for adaptive optics with reflected light and deep neural networks…

Optics · Physics 2020-07-28 Ivan Vishniakou , Johannes D. Seelig

Several recent studies show that bright, intermediate and high redshift optically and radio selected QSOs are positively correlated with nearby galaxies on a range of angular scales up to a degree. Obscuration by unevenly distributed…

Astrophysics · Physics 2009-10-31 Liliya L. R. Williams

Extreme adaptive optics systems are now in operation across the globe. These systems, capable of high order wavefront correction, deliver Strehl ratios of 90% in the near-infrared. Originally intended for the direct imaging of exoplanets,…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 Nemanja Jovanovic , Christian Schwab , Nick Cvetojevic , Olivier Guyon , Frantz Martinache

Monitoring the evolution of the anthropogenic light emissions is a priority task in light pollution research. Among the complementary approaches that can be adopted to achieve this goal stand out those based on measuring the direct radiance…

Instrumentation and Methods for Astrophysics · Physics 2024-10-31 Salvador Bará

Fluorescence Correlation Spectroscopy (FCS) yields measurement parameters (number of molecules, diffusion time) that characterize the concentration and kinetics of fluorescent molecules within a supposedly known observation volume. Absolute…

Biological Physics · Physics 2011-12-23 Charles Edouard Leroux , Irène Wang , Jacques Derouard , Antoine Delon

We compare coronagraph concepts and investigate their behavior and suitability for planet finder projects with Extremely Large Telescopes (ELTs, 30-42 meters class telescopes). For this task, we analyze the impact of major error sources…

Astrophysics · Physics 2009-11-13 P. Martinez , A. Boccaletti , M. Kasper , C. Cavarroc , N. Yaitskova , T. Fusco , C. Verinaud

The reconstruction of a smooth field onto a fixed grid is a necessary step for direct comparisons to various real-world observations. Projecting SPH data onto a fixed grid becomes challenging in adaptive environments, where some particles…

Astrophysics of Galaxies · Physics 2021-06-14 Josh Borrow , Ashley J. Kelly

At low redshift, it is possible to combine spectroscopic information of galaxies with their luminosity or angular diameter distance to directly measure the projection of peculiar velocities (PV) along the line-of-sight. A PV survey probing…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-02 Mattia Pantiri , Matteo Foglieni , Enea Di Dio , Emanuele Castorina

Adaptive optics (AO) instruments for the future extremely large telescopes (ELTs) are characterized by advanced optical systems with diffraction-limited optical quality. Low geometric distortion is also crucial for high accuracy astrometric…

Instrumentation and Methods for Astrophysics · Physics 2019-04-02 Mauro Patti , Matteo Lombini , Edoardo Maria Alberto Redaelli , Emiliano Diolaiti

Atmospheric regions below a refractive boundary are hidden in limb observations. Refraction thus creates a gray continuum in the planet's transmission spectrum which can hide spectral features associated with sources of atmospheric opacity.…

Earth and Planetary Astrophysics · Physics 2018-09-19 Yan Bétrémieux , Mark R. Swain

Telescope pupil fragmentation from spiders generates specific aberrations observed at various telescopes and expected on the large telescopes under construction. This so-called island effect induces differential pistons, tips and tilts on…

The high-speed variability of the local water vapor content in the Earth atmosphere is a significant contributor to ground-based wavefront quality throughout the infrared domain. Unlike dry air, water vapor is highly chromatic, especially…

We calculate corrections to the power spectrum predictions of weak lensing by large scale structure due to higher order effects in the gravitational potential. Using a perturbative approach to third order in transverse displacements, we…

Astrophysics · Physics 2011-05-12 Asantha Cooray , Wayne Hu

A new generation of telescopes with mirror diameters of 20 m or more, called extremely large telescopes (ELTs) has the potential to provide unprecedented imaging and spectroscopy of exo-planetary systems, if the difficulties in achieving…

Instrumentation and Methods for Astrophysics · Physics 2016-04-20 Richard A. Frazin

The Galactic center offers us a unique opportunity to test General Relativity (GR) with the orbits of stars around a supermassive black hole. Observations of these stars have been one of the great successes of adaptive optics on 8-10 m…

Astrophysics of Galaxies · Physics 2017-11-20 Tuan Do , Aurelien Hees , Arezu Dehghanfar , Andrea Ghez , Shelley Wright
‹ Prev 1 4 5 6 7 8 10 Next ›