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Publicações

Publicações por CTM

2024

High contrast at short separation with VLTI/GRAVITY: Bringing Gaia companions to light

Autores
Pourré, N; Winterhalder, TO; Le Bouquin, J; Lacour, S; Bidot, A; Nowak, M; Maire, A; Mouillet, D; Babusiaux, C; Woillez, J; Abuter, R; Amorim, A; Asensio Torres, R; Balmer, WO; Benisty, M; Berger, J; Beust, H; Blunt, S; Boccaletti, A; Bonnefoy, M; Bonnet, H; Bordoni, MS; Bourdarot, G; Brandner, W; Cantalloube, F; Caselli, P; Charnay, B; Chauvin, G; Chavez, A; Choquet, E; Christiaens, V; Clénet, Y; Du Foresto, V; Cridland, A; Davies, R; Defrère, D; Dembet, R; Dexter, J; Drescher, A; Duvert, G; Eckart, A; Eisenhauer, F; Schreiber, NM; Garcia, P; Lopez, R; Gendron, E; Genzel, R; Gillessen, S; Girard, JH; Gonte, F; Grant, S; Haubois, X; Heiãà  El, G; Henning, T; Hinkley, S; Hippler, S; Hönig, SF; Houllé, M; Hubert, Z; Jocou, L; Kammerer, J; Kenworthy, M; Keppler, M; Kervella, P; Kreidberg, L; Kurtovic, NT; Lagrange, A; Lapeyrère, V; Lutz, D; Mang, F; Marleau, G; Mérand, A; Millour, F; Mollière, P; Monnier, JD; Mordasini, C; Nasedkin, E; Oberti, S; Ott, T; Otten, GPPL; Paladini, C; Paumard, T; Perraut, K; Perrin, G; Pfuhl, O; Pueyo, L; Ribeiro, DC; Rickman, E; Rustamkulov, Z; Shangguan, J; Shimizu, T; Sing, D; Soulez, F; Stadler, J; Stolker, T; Straub, O; Straubmeier, C; Sturm, E; Sykes, C; Tacconi, LJ; Van Dishoeck, EF; Vigan, A; Vincent, F; Von Fellenberg, SD; Wang, JJ; Widmann, F; Yazici, S; Abad, JA; Aller Carpentie, E; Alonso, J; Andolfato, L; Barriga, P; Beuzit, J; Bourget, P; Brast, R; Caniguante, L; Cottalorda, E; Darré, P; Delabre, B; Delboulbé, A; Delplancke Ströbele, F; Donaldson, R; Dorn, R; Dupuy, C; Egner, S; Fischer, G; Frank, C; Fuenteseca, E; Gitton, P; Guerlet, T; Guieu, S; Gutierrez, P; Haguenauer, P; Haimerl, A; Heritier, CT; Huber, S; Hubin, N; Jolley, P; Kirchbauer, J; Kolb, J; Kosmalski, J; Krempl, P; Le Louarn, M; Lilley, P; Lopez, B; Magnard, Y; McLay, S; Meilland, A; Meister, A; Moulin, T; Pasquini, L; Paufique, J; Percheron, I; Pettazzi, L; Phan, D; Pirani, W; Quentin, J; Rakich, A; Ridings, R; Reyes, J; Rochat, S; Schmid, C; Schuhler, N; Shchekaturov, P; Seidel, M; Soenke, C; Stadler, E; Stephan, C; Suárez, M; Todorovic, M; Valdes, G; Verinaud, C; Zins, G; Zúñiga Fernández, S;

Publicação
ASTRONOMY & ASTROPHYSICS

Abstract
Context. Since 2019, GRAVITY has provided direct observations of giant planets and brown dwarfs at separations of down to 95 mas from the host star. Some of these observations have provided the first direct confirmation of companions previously detected by indirect techniques (astrometry and radial velocities). Aims. We want to improve the observing strategy and data reduction in order to lower the inner working angle of GRAVITY in dual-field on-axis mode. We also want to determine the current limitations of the instrument when observing faint companions with separations in the 30-150 mas range. Methods. To improve the inner working angle, we propose a fiber off-pointing strategy during the observations to maximize the ratio of companion-light-to-star-light coupling in the science fiber. We also tested a lower-order model for speckles to decouple the companion light from the star light. We then evaluated the detection limits of GRAVITY using planet injection and retrieval in representative archival data. We compare our results to theoretical expectations. Results. We validate our observing and data-reduction strategy with on-sky observations; first in the context of brown dwarf follow-up on the auxiliary telescopes with HD 984 B, and second with the first confirmation of a substellar candidate around the star Gaia DR3 2728129004119806464. With synthetic companion injection, we demonstrate that the instrument can detect companions down to a contrast of 8 x 10(-4) (Delta K = 7.7 mag) at a separation of 35 mas, and a contrast of 3 x 10(-5) (Delta K = 11 mag) at 100 mas from a bright primary (K < 6.5), for 30 min exposure time. Conclusions. With its inner working angle and astrometric precision, GRAVITY has a unique reach in direct observation parameter space. This study demonstrates the promising synergies between GRAVITY and Gaia for the confirmation and characterization of substellar companions.

2024

GRAVITY plus Wide: Towards hundreds of z ~ 2 AGN, larger throughput and improved vibrational control

Autores
Fabricius, M; Woillez, J; Abuter, R; Bourdarot, G; Bourget, P; Brandner, W; Brara, A; Defrère, D; Drescher, A; Eisenhauer, F; Feuchtgruber, H; Frahm, R; Genzel, R; Gillessen, S; Gonté, F; Gopinath, V; Graf, J; Hartl, M; Haussmann, F; Hönig, SF; Horrobin, M; Garcia, PJ; Jilg, T; Kreidberg, L; Laugier, R; Le Bouquin, JB; Bolzer, ML; Lutz, D; More, N; Ott, T; Özdemir, H; Paumard, T; Perraut, K; Perrin, G; Rau, C; Rehm, C; Sauter, J; Schuhler, N; Schuppe, D; Shangguan, JY; Shimizu, T; Straubmeier, C; Subroweit, M; Uysal, S; Wessely, P; Widmann, F; Wieprecht, E; Wimmer, L; Yazici, S; Prowatke, H; Böttcher, R;

Publicação
OPTICAL AND INFRARED INTERFEROMETRY AND IMAGING IX

Abstract
In the GRAVITY+ project, GRAVITY is presently undergoing a series of upgrades to enhance its performance, add wide field capability and thereby expand its sky coverage. Some aspects of these improvements have already been implemented and commissioned by the end of 2021, making them accessible to the community. The augmentation of sky coverage involves increasing the maximum angular separation between the celestial science object and the fringe tracking object from the previous 2 arcseconds (limited by the field of view of the VLTI) to 20 - 30 arcseconds (constrained by atmospheric conditions during observation). Phase 1 of GRAVITY+ Wide utilizes the earlier PRIMA Differential Delay Lines to compensate for the optical path length variation between the science and fringe tracking beams throughout an observation. In phase 2, we are upgrading the existing beam compressors (BC) to integrate optical path length difference compensation directly into the BC. This modification eliminates five optical reflections per beam, thereby enhancing the optical throughput of the VLTI-GRAVITY [GRAPHICS] system and the bandwidth of the vibrational control. We will present the implementation of phase 2 and share preliminary results from our testing activities for GRAVITY+ Wide.

2024

Gravity plus Adaptive Optics (GPAO) tests in Europe

Autores
Millour, F; Bourdarot, G; Le Bouquin, JB; Berdeu, A; Houllé, M; Berio, P; Paumard, T; Defrère, D; Garcia, P; Soulez, F; Hoenig, S; Allouche, F; Bachbucher, M; Bailet, C; Blanchard, C; Boebion, O; Bonnet, H; Brara, A; Carbillet, M; Czempiel, S; Delboulbé, A; Dembet, R; Edouard, C; Eisenhauer, F; Feuchtgruber, H; Furchstsam, C; Gillessen, S; Goldbrunner, A; Gomes, T; Gouvvret, C; Guieu, S; Hartl, M; Hartwig, J; Haussmann, F; Huber, D; Ibn Taïeb, I; Kolb, J; Lagarde, S; Lai, O; Leftley, J; Lutz, D; Magnard, Y; Marcotto, A; Nowacki, H; Oberti, S; Ott, T; Rau, C; Robbe-Dubois, S; Scigliuto, J; Soller, F; Shchekaturov, P; Schuppe, D; Stadler, E; Uysal, S; Widmann, F; Wieprecht, E; Woillez, J; Yazici, S;

Publicação
OPTICAL AND INFRARED INTERFEROMETRY AND IMAGING IX

Abstract
We present in this proceeding the results of the test phase of the GRAVITY+ adaptive optics. This extreme AO will enable both high-dynamic range observations of faint companions (including exoplanets) thanks to a 40x40 sub-apertures wavefront control, and sensitive observations (including AGNs) thanks to the addition of a laser guide star to each UT of the VLT. This leap forward is made thanks to a mostly automated setup of the AO, including calibration of the NCPAs, that we tested in Europe on the UT+atmosphere simulator we built in Nice. We managed to reproduce in laboratory the expected performances of all the modes of the AO, including under non-optimal atmospheric or telescope alignment conditions, giving us the green light to proceed with the Assembly, Integration and Verification phase in Paranal.

2024

Overcoming Obstacles to the Assembly, Integration and Testing of the WSS/METIS

Autores
Filho, M; Amorim, A; Carvalho, F; Garcia, P;

Publicação
MODELING, SYSTEMS ENGINEERING, AND PROJECT MANAGEMENT FOR ASTRONOMY XI, PT 1

Abstract
The WSS is a subsystem being designed and manufactured by the CENTRA team ( Portugal) for the ESO ELT first light instrument METIS. The WSS consists of three substructures - the support system (ELP), the alignment system (CAS), and the access and maintenance system (RIG). In total, the WSS dimensions are approximately 6 x 6 x 6 meters. In order to fully assemble, integrate, and test such a large structure, an integration hall of at least 2.5 times the WSS volume would be required to accommodate the necessary lateral and vertical clearance around WSS. Such integration halls are not readily available or accessible. In order to overcome this challenge, we have devised a 3-step strategy to assemble, integrate, and test the WSS at three different locations in three different configurations.

2024

Opto-mechanical design of GRAVITY plus Wavefront Sensor

Autores
More, N; Genzel, R; Eisenhauer, F; Lutz, D; Gillessen, S; Schubert, J; Hartl, M; Haussmann, F; Rehm, C; Weisz, H; Yazici, S; Feuchtgruber, H; Rau, C; Uysal, S; Bourdarot, G; Wieprecht, E; Ott, T; Fabricius, M; Widmann, F; Drescher, A; Shangguan, J; Shimizu, T; Gonté, F; Woillez, J; Schuhler, N; Bourget, P; Oberti, S; Le Bouquin, JB; Paumard, T; Millour, F; Straubmeier, C; Kreidberg, L; Garcia, P; Gomes, T; Hoenig, S; Defrére, D;

Publicação
OPTICAL AND INFRARED INTERFEROMETRY AND IMAGING IX

Abstract
The GRAVITY+ project consists of instrumental upgrades to the Very Large Telescope Interferometer (VLTI) for faint-science, high-contrast, milliarcsecond interferometric imaging. As an integral part of the GRAVITY+ Adaptive Optics (AO) architecture, the Wavefront Sensor (WFS) subsystem corrects image distortions caused by the turbulence of Earth's atmosphere. We present the opto-mechanical design of the WFS subsystem and the design strategies used to implement two payloads positioned diagonally opposite each other - Natural Guide Star (NGS) and Laser Guide Star (LGS) - within a single compact design structure. We discuss the implementation of relative motions of the two payloads covering their respective patrol fields and a nested motion within the LGS Payload covering the complete Sodium layer profile in the Earth's atmosphere.

2024

Open loop calibration and closed loop non perturbative estimation of the lateral errors of an adaptive optics system: examples with GRAVITY plus and CHARA experimental data

Autores
Berdeu, A; Bonnet, H; Le Bouquin, JB; Kolb, I; Bourdarot, G; Berio, P; Paumard, T; Eisenhauer, F; Straubmeier, C; Garcia, P; Hönig, S; Millour, F; Kreidberg, L; Defrère, D; Soulez, F; Mourard, D; Schaefer, G; Anugum, N;

Publicação
ADAPTIVE OPTICS SYSTEMS IX

Abstract
Performances of an adaptive optics (AO) system are directly linked with the quality of its alignment. During the instrument calibration, having open loop fast tools with a large capture range are necessary to quickly assess the system misalignment and to drive it towards a state allowing to close the AO loop. During operation, complex systems are prone to misalignments (mechanical flexions, rotation of optical elements,...) that potentially degrade the AO performances, creating a need for a monitoring tool to tackle their driftage. In this work, we first present an improved perturbative method to quickly assess large lateral errors in open loop. It uses the spatial correlation of the measured interaction matrix of a limited number of 2D spatial modes with a synthetic model. Then, we introduce a novel solution to finely measure and correct these lateral errors via the closed loop telemetry. Non-perturbative, this method consequently does not impact the science output of the instrument. It is based on the temporal correlation of 2D spatial frequencies in the deformable mirror commands. It is model-free (no need of an interaction matrix model) and sparse in the Fourier space, making it fast and easily scalable to complex systems such as future extremely large telescopes. Finally, we present some results obtained on the development bench of the GRAVITY+ extreme AO system (Cartesian grid, 1432 actuators). In addition, we show with on-sky results gathered with CHARA and GRAVITY/CIAO that the method is adaptable to non-conventional AO geometries (hexagonal grids, 60 actuators).

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