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Publicações

Publicações por Carlos Manuel Correia

2020

The multi-object adaptive optics system for the Gemini infra-red multi-object spectrograph

Autores
Chapman S.C.; Conod U.; Turri P.; Jackson K.; Lardiere O.; Sivanandam S.; Andersen D.; Correia C.; Lamb M.; Ross C.; Sivo G.; Veran J.P.;

Publicação
Proceedings of SPIE - The International Society for Optical Engineering

Abstract
The Gemini Infra-Red Multi-Object Spectrograph (GIRMOS) is a four-arm, Multi-Object Adaptive Optics (MOAO) IFU spectrograph being built for Gemini (commissioning in 2024). GIRMOS is being planned to interface with the new Gemini-North Adaptive Optics (GNAO) system, and is base lined with a requirement of 50% EE within a 0.100 spaxel at H-band. We present a design and forecast the error budget and performance of GIRMOS-MOAO working behind GNAO. The MOAO system will patrol the 20 field of regard of GNAO, utilizing closed loop GLAO or MCAO for lower order correction. GIRMOS MOAA will perform tomographic reconstruction of the turbulence using the GNAO WFS, and utilize order 16x16 actuator DMs operating in open loop to perform an additional correction from the Pseudo Open Loop (POL) slopes, achieving close to diffraction limited performance from the combined GNAO+MOAO correction. This high performance AO spectrograph will have the broadest impact in the study of the formation and evolution of galaxies, but will also have broad reach in fields such as star and planet formation within our Milky Way and supermassive black holes in nearby galaxies.

2020

HARMONI - First light spectrograph for the ELT: Instrument final design and quantitative performance predictions

Autores
Thatte N.A.; Bryson I.; Clarke F.; Ferraro-Wood V.; Fusco T.; Le Mignant D.; Melotte D.; Neichel B.; Schnetler H.; Tecza M.; Arribas S.; Crespo A.; Piqueras A.E.; García M.G.; Santaella M.P.; Lopez J.P.; Blaizot J.; Bouché N.; Boudon D.; Chapuis D.; Daguise E.; Disseau K.; Guibert M.; Jarno A.; Jeanneau A.; Laurent F.; Loupias M.; Migniau J.E.; Piqueras L.; Remillieux A.; Richard J.; Pecontal A.; Bardou L.; Close M.; Deshmukh R.; Dimoudi S.; Dubbledam M.; King D.; Morris S.; Morris T.; O'Brien K.; Staykov L.; Swinbank M.; Townson M.; Younger E.; Accardo M.; Mendez D.A.; Conzelmann R.; Egner S.; George E.; Gonté F.; Hopgood J.; Ives D.; Mehrgan L.; Mueller E.; Peroux C.; Vernet J.; Sanchez A.A.; Battaglia G.; Cagigas M.; Delgado J.M.; Izquierdo P.F.; López A.B.F.; Garcia-Lorenzo B.; Suarez E.H.; Herreros J.M.; Joven E.; López R.; Hernando Y.M.; Mediavilla E.; Monreal A.; Castro J.P.; Rasilla J.L.; Rebolo R.; Ramos L.F.R.; Moreno A.V.; Viera T.; Carlotti A.; Correia J.J.; Delboulbe A.; Guieu S.; Hours A.; Hubert Z.; Jocou L.; Magnard Y.; Moulin T.; Pancher F.; Rabou P.; Stadler E.; Contini T.; Larrieu M.; Fantei-Caujolle Y.; Lecron D.; Rousseau S.; Beltramo-Martin O.; Bon W.; Bonnefoi A.; Ceria W.; Choquet E.; Correia C.;

Publicação
Proceedings of SPIE - The International Society for Optical Engineering

Abstract
HARMONI is the adaptive optics assisted, near-infrared and visible light integral field spectrograph for the Extremely Large Telescope (ELT). A first light instrument, it provides the work-horse spectroscopic capability for the ELT. As the project approaches its Final Design Review milestone, the design of the instrument is being finalized, and the plans for assembly, integration and testing are being detailed. We present an overview of the instrument's capabilities from a user perspective, provide a summary of the instrument's design, including plans for operations and calibrations, and provide a brief glimpse of the predicted performance for a specific observing scenario. The paper also provides some details of the consortium composition and its evolution since the project commenced in 2015.

2020

Wind-driven halo in high-contrast images: I. Analysis of the focal-plane images of SPHERE

Autores
Cantalloube, F; Farley, OJD; Milli, J; Bharmal, N; Brandner, W; Correia, C; Dohlen, K; Henning, T; Osborn, J; Por, E; Valles, MS; Vigan, A;

Publicação
ASTRONOMY & ASTROPHYSICS

Abstract
Context. The wind-driven halo is a feature that is observed in images that were delivered by the latest generation of ground-based instruments that are equipped with an extreme adaptive optics system and a coronagraphic device, such as SPHERE at the Very Large Telescope (VLT). This signature appears when the atmospheric turbulence conditions vary faster than the adaptive optics loop can correct for. The wind-driven halo is observed as a radial extension of the point spread function along a distinct direction (this is sometimes referred to as the butterfly pattern). When this is present, it significantly limits the contrast capabilities of the instrument and prevents the extraction of signals at close separation or extended signals such as circumstellar disks. This limitation is consequential because it contaminates the data for a substantial fraction of the time: about 30% of the data produced by the VLT/SPHERE instrument are affected by the wind-driven halo. Aims. This paper reviews the causes of the wind-driven halo and presents a method for analyzing its contribution directly from the scientific images. Its effect on the raw contrast and on the final contrast after post-processing is demonstrated. Methods. We used simulations and on-sky SPHERE data to verify that the parameters extracted with our method can describe the wind-driven halo in the images. We studied the temporal, spatial, and spectral variation of these parameters to point out its deleterious effect on the final contrast. Results. The data-driven analysis we propose provides information to accurately describe the wind-driven halo contribution in the images. This analysis confirms that this is a fundamental limitation of the finally reached contrast performance. Conclusions. With the established procedure, we will analyze a large sample of data delivered by SPHERE in order to propose post-processing techniques that are tailored to removing the wind-driven halo.

2020

GNAO: An MCAO facility for Gemini North

Autores
Sivo G.; Palmer D.; Scahrwächter J.; Andersen M.; Provost N.; Marin E.; Van Dam M.; Chinn B.; Chirre E.; Cavedoni C.; Schneider T.; Kang S.; Hirst P.; Rambold W.; Ebbers A.; Gigoux P.; Catala L.; Hayward T.; Blakeslee J.; Roe H.; Lotz J.; Kleinman S.; Sivanandam S.; Krause A.; Ammons M.; Trujillo C.; Packham C.; Marchis F.; Christou J.; Jee J.; Bally J.; Pierce M.; Puzia T.; Turri P.; Kim H.; Schwamb M.; Dupuy T.; Diaz R.; Carrasco R.; Neichel B.; Correia C.; Steinbring E.; Rigaut F.; Véran J.P.; Chun M.; Lamb M.; Chapman S.; Esposito S.; Fusco T.;

Publicação
Proceedings of SPIE - The International Society for Optical Engineering

Abstract
Gemini Observatory has been awarded a major funding from the National Science Foundation to build a complete new state of the art multi-conjugate adaptive optics system for Gemini North. The system will be designed to provide an MCAO facility delivering close to diffraction limit correction in the near-infrared over a 2 arcminutes field of view and feed imaging and spectroscopic instruments. We present in this paper the results of the conceptual design phase with details on the new proposed laser guide star facilities and adaptive optics bench. We will present results on the performance simulation assessments as well as the developed selected science cases.

2020

Reconstruction of the ground-layer adaptive-optics point spread function for MUSE wide field mode observations

Autores
Fusco, T; Bacon, R; Kamann, S; Conseil, S; Neichel, B; Correia, C; Beltramo Martin, O; Vernet, J; Kolb, J; Madec, PY;

Publicação
ASTRONOMY & ASTROPHYSICS

Abstract
Context. 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 (MUSE) wide field mode. Aims. Based on clear astrophysical requirements derived by the MUSE team and using the functionality of the current ESO Adaptive Optics Facility we aim to develop an operational PSF-reconstruction (PSFR) algorithm and test it both in simulations and using on-sky data. Methods. The PSFR approach is based on a Fourier description of the GLAO correction to which the specific instrumental effects of MUSE wide field mode (pixel size, internal aberrations, etc.) have been added. It was first thoroughly validated with full end-to-end simulations. Sensitivity to the main atmospheric and AO system parameters was analysed and the code was re-optimised to account for the sensitivity found. Finally, the optimised algorithm was tested and commissioned using more than one year of on-sky MUSE data. Results. We demonstrate with an on-sky data analysis that our algorithm meets all the requirements imposed by the MUSE scientists, namely an accuracy better than a few percent on the critical PSF parameters including full width at half maximum and global PSF shape through the kurtosis parameter of a Moffat function. Conclusions. The PSFR algorithm is publicly available and is used routinely to assess the MUSE image quality for each observation. It can be included in any post-processing activity which requires knowledge of the PSF.

2020

Limitations imposed by optical turbulence profile structure and evolution on tomographic reconstruction for the ELT

Autores
Farley, OJD; Osborn, J; Morris, T; Fusco, T; Neichel, B; Correia, C; Wilson, RW;

Publicação
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

Abstract
The performance of tomographic adaptive optics (AO) systems is intrinsically linked to the vertical profile of optical turbulence. First, a sufficient number of discrete turbulent layers must be reconstructed to model the true continuous turbulence profile. Secondly over the course of an observation, the profile as seen by the telescope changes and the tomographic reconstructor must be updated. These changes can be due to the unpredictable evolution of turbulent layers on meteorological time-scales as short as minutes. Here, we investigate the effect of changing atmospheric conditions on the quality of tomographic reconstruction by coupling fast analyticalAOsimulation to a large data base of 10 691 high-resolution turbulence profiles measured over two years by the Stereo-SCIDAR instrument at ESO Paranal, Chile. This work represents the first investigation of these effects with a large, statistically significant sample of turbulence profiles. The statistical nature of the study allows us to assess not only the degradation and variability in tomographic error with a set of system parameters (e.g. number of layers and temporal update period), but also the required parameters to meet some error threshold. In the most challenging conditions where the profile is rapidly changing, these parameters must be far more tightly constrained in order to meet this threshold. By providing estimates of these constraints for a wide range of system geometries as well as the impact of different temporal optimization strategies we may assist the designers of tomographic AO for the extremely large telescope to dimension their systems.

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