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Caltech Authors (170.931 recursos)

Repository of works by Caltech published authors.

Group = Thirty Meter Telescope

Mostrando recursos 1 - 20 de 35

  1. The Highly Polarized Dusty Emission Core of Cygnus A

    Lopez-Rodriguez, Enrique; Antonucci, Robert; Chary, Ranga-Ram; Kishimoto, Makoto
    We report the detection of linearly polarized emission at 53 and 89 μm from the radio-loud active galactic nucleus (AGN) Cygnus A using High-resolution Airborne Wideband Camera-plus (HAWC+) on board the Stratospheric Observatory For Infrared Astronomy (SOFIA). We measure a highly polarized core of 11 ± 3% and 9 ± 2% with a position angle (PA) of polarization of 43° ± 8° and 39° ± 7° at 53 and 89 μm, respectively. We find (1) a synchrotron-dominated core with a flat spectrum (+0.21 ± 0.05) and a turnover at 543 ± 120 μm, which implies synchrotron emission is insignificant in...

  2. The Thirty Meter Telescope site testing system

    Skidmore, Warren; Schöck, Matthias; Tokovinin, Andrei; Djorgovski, George; Walker, Alistair; Blum, Robert; Travouillon, Tony; Seguel, Juan; Bustos, Edison; Walker, David; Vasquez, Joselino; Gillett, Paul
    The Thirty Meter Telescope (TMT) site testing team are developing a suite of instruments to measure the atmospheric and optical characteristics of candidate TMT sites. Identical sets of robotically operating instruments will be placed at each candidate site. The fully developed system will comprise of a combined MASS/DIMM. a SODAR, tower mounted thermal probes and a portable DIMM. These instruments have overlapping altitude coverage and provide a measure of the C^2_n profile from the ground up with sufficient resolution to make conclusions about the ground layer and high altitude turbulence characteristics. The overlapping altitude coverage is essential to ensure consistency...

  3. Systems engineering of the Thirty Meter Telescope for the construction phase

    Roberts, Scott; Rogers, John; Thompson, Hugh; Vogiatzis, Konstantinos; MacMartin, Douglas; Wilde, Eric; Troy, Mitchell; Seo, Byoung-Joon; Nissly, Carl
    This paper provides an overview of the system design, architecture, and construction phase system engineering processes of the Thirty Meter Telescope project. We summarize the key challenges and our solutions for managing TMT systems engineering during the construction phase. We provide an overview of system budgets, requirements and interfaces, and the management thereof. The requirements engineering processes, including verification and plans for collection of technical data and testing during the assembly and integration phases, are described. We present configuration, change control and technical review processes, covering all aspects of the system design including performance models, requirements, and CAD databases.

  4. First light adaptive optics systems and components for the Thirty Meter Telescope

    Ellerbroek, Brent; Boyer, Corinne; Gilles, Luc; Wang, Lianqi
    Adaptive optics (AO) is essential for many elements of the science case for the Thirty Meter Telescope (TMT). The initial requirements for the observatory's facility AO system include diffraction-limited performance in the near IR, with 50 per cent sky coverage at the galactic pole. Point spread function uniformity and stability over a 30 arc sec field-ofview are also required for precision photometry and astrometry. These capabilities will be achieved via an order 60×60 multi-conjugate AO system (NFIRAOS) with two deformable mirrors, six laser guide star wavefront sensors, and three low-order, IR, natural guide star wavefront sensors within each client instrument....

  5. GeMS: first on-sky results

    Rigaut, François; Ellerbroek, Brent
    GeMS, the Gemini Laser Guide Star Multi-Conjugate Adaptive Optics facility system, has seen first light in December 2011, and has already produced images with H band Strehl ratio in excess of 35% over fields of view of 85x85 arcsec, fulfilling the MCAO promise. In this paper, we report on these early results, analyze trends in performance, and concentrate on key or novel aspects of the system, like centroid gain estimation, on-sky non­ common path aberration estimation. We also present the first astrometric analysis, showing very encouraging results.

  6. Analysis of Normalized Point Source Sensitivity as a performance metric for the Thirty Meter Telescope

    Seo, Byoung-Joon; Nissly, Carl; Angeli, George; Ellerbroek, Brent; Nelson, Jerry; Sigrist, Norbert; Troy, Mitchell
    We investigate a new metric, Normalized Point Source Sensitivity (PSSN), for characterizing the seeing limited performance of the Thirty Meter Telescope. As the PSSN metric is directly related to the photometric error of background limited observations, it truly represents the efficiency loss in telescope observing time. The PSSN metric properly accounts for the optical consequences of wavefront spatial frequency distributions due to different error sources, which makes it superior to traditional metrics such as the 80% encircled energy diameter. We analytically show that multiplication of individual PSSN values due to individual errors is a good approximation for the total PSSN...

  7. TMT adaptive optics program status report

    Ellerbroek, Brent; Boyer, Corinne; Gilles, Luc; Schoeck, Matthias; Wang, Lianqi
    We provide an update on the development of the first light adaptive optics systems for the Thirty Meter Telescope (TMT) over the past two years. The first light AO facility for TMT consists of the Narrow Field Infra-Red AO System (NFIRAOS) and the associated Laser Guide Star Facility (LGSF). This order 60 × 60 laser guide star (LGS) multi-conjugate AO (MCAO) architecture will provide uniform, diffraction-limited performance in the J, H, and K bands over 17-30 arc sec diameter fields with 50 per cent sky coverage at the galactic pole, as is required to support TMT science cases. Both NFIRAOS...

  8. The Infrared Imaging Spectrograph (IRIS) for TMT: on-instrument wavefront sensors (OIWFS) and NFIRAOS interface

    Loop, David; Reshetov, Vlad; Fletcher, Murray; Wooff, Robert; Dunn, Jennifer; Moore, Anna; Smith, Roger; Hale, David; Dekany, Richard; Wang, Lianqi; Ellerbroek, Brent; Simard, Luc; Crampton, David
    The InfraRed Imaging Spectrograph (IRIS) is a first light client science instrument for the TMT observatory that operates as a client of the NFIRAOS facility multi-conjugate adaptive optics system. This paper reports on the concept study and baseline concept design of the On-Instrument WaveFront Sensors (OIWFS) and NFIRAOS interface subsystems of the IRIS science instrument, a collaborative effort by NRC-HIA, Caltech, and TMT AO and Instrument teams. This includes work on system engineering, structural and thermal design, sky coverage modeling, patrol geometry, probe optics and mechanics design, camera design, and controls design.

  9. TMT NFIRAOS: adaptive optics system for the Thirty Meter Telescope

    Herriot, Glen; Andersen, David; Atwood, Jenny; Byrnes, Peter; Boucher, Marc-Andre; Boyer, Corrine; Caputa, Kris; Correia, Carlos; Dunn, Jennifer; Ellerbroek, Brent; Fitzsimmons, Joeleff; Gilles, Luc; Hickson, Paul; Hill, Alexis; Kerley, Dan; Pazder, John; Reshetov, Vlad; Roberts, Scott; Smith, Malcolm; Véran, Jean-Pierre; Wang, Lianqi; Wevers, Ivan
    NFIRAOS is the first-light adaptive optics system planned for the Thirty Meter Telescope, and is being designed at the National Research Council of Canada's Herzberg Institute of Astrophysics. NFIRAOS is a laser guide star multiconjugate adaptive optics system - a practical approach to providing diffraction limited image quality in the NIR over a 30" field of view, with high sky coverage. This will enable a wide range of TMT science that depends upon the large corrected field of view and high precision astrometry and photometry. We review recent progress developing the design and conducting performance estimates for NFIRAOS.

  10. High fidelity optical modeling for the TMT

    Nissly, Carl; Seo, Byoung-Joon; Troy, Mitchell; Angeli, George; Cho, Myung; Ellerbroek, Brent; Piatrou, Piotr; Roberts, Lewis C., Jr.; Shelton, J. Chris; Wang, Lianqi
    The Thirty Meter Telescope (TMT) is a Ritchey-Chritien optical telescope with a 30-meter diameter primary mirror made up of 492 hexagonal segments. Such a large and complex optical system requires detailed modeling of the optical performance during the design phase. An optical modeling computational framework has been developed to support activities related to wavefront & image performance prediction. The model includes effects related to mirror shape sensing & control, mirror alignment & phasing, M1 segment control, low order wavefront correction, adaptive optics simulation for high order wavefront correction, and high contrast imaging. Here we give an overview of this optical...

  11. Adaptive optics program update at TMT

    Boyer, C.; Ellerbroek, B.
    The TMT first light AO facility consists of the Narrow Field Infra-Red AO System (NFIRAOS), the associated Laser Guide Star Facility (LGSF) and the AO Executive Software (AOESW). Design, fabrication and prototyping activities of the TMT first light AO systems and their components have significantly ramped up in Canada, China, France, and in the US. NFIRAOS is an order 60 x 60 laser guide star (LGS) multi-conjugate AO (MCAO) system, which provides uniform, diffraction-limited performance in the J, H, and K bands over 34 x 34 arc sec fields with 50 per cent sky coverage at the galactic pole, as...

  12. NFIRAOS: TMT's facility adaptive optics system

    Herriot, Glen; Andersen, David; Atwood, Jennifer; Boyer, Corrine; Beauvillier, Annie; Byrnes, Peter; Conan, Rod; Ellerbroek, Brent; Fitzsimmons, Joeleff; Gilles, Luc; Hickson, Paul; Hill, Alexis; Jackson, Kate; Lardière, Olivier; Pazder, John; Pfrommer, Thomas; Reshetov, Vlad; Roberts, Scott; Véran, Jean-Pierre; Wang, Lianqi; Wevers, Ivan
    NFIRAOS, the TMT Observatory's initial facility AO system is a multi-conjugate AO system feeding science light from 0.8 to 2.5 microns wavelength to several near-IR client instruments. NFIRAOS has two deformable mirrors optically conjugated to 0 and 11.2 km, and will correct atmospheric turbulence with 50 per cent sky coverage at the galactic pole. An important requirement is to have very low background: the plan is to cool the optics; and one DM is on a tip/tilt stage to reduce surface count. NFIRAOS' real time control uses multiple sodium laser wavefront sensors and up to three IR natural guide star...

  13. TMT DMs final design and advanced prototyping results at Cilas

    Sinquin, Jean-Christophe; Bastard, Arnaud; Boyer, Corinne; Cornette, Sébastien; Cousty, Raphaël; Ellerbroek, Brent; Gilbert, Xavier; Gourdet, Benoit; Grasser, Régis; Groeninck, Denis; Guillemard, Claude; Herriot, Glen; Iannacone, Albert; Jeulin, Antoine; Moreau, Aurélein; Pagès, Hubert; Wang, Lianqi
    In order to prepare for the construction phase of the two Deformable Mirrors (DMs), which will be used in the Thirty Meter Telescope (TMT) first light Adaptive Optics (AO) system, Cilas has advanced the design of these two large size piezo DMs and has manufactured and tested a scaled demonstration prototype. The work done allowed significant reduction of the risks related to the demanding specifications of the TMT DMs; the main issues were: (i) Large pupil (up to 370 mm) and high order (up to 74x74); (ii) Relatively low operational temperature (DMs working at -30°C); (iii) New piezo material. It...

  14. Aero-thermal simulations of the TMT Laser Guide Star Facility

    Vogiatzis, Konstantinos; Boyer, Corrine; Wei, Kai; Tang, Jinlong; Ellerbroek, Brent
    The Laser Guide Star Facility (LGSF) system of the Thirty Meter Telescope (TMT) will generate the artificial laser guide stars required by the TMT Adaptive Optics (AO) systems. The LGSF uses multiple sodium lasers to generate and project several asterisms from a laser launch telescope located behind the TMT secondary mirror. The laser beams are transported from a location below the primary mirror to the launch telescope using conventional optics to relay the beams along the telescope structure. The beams and relay optics are enclosed into hermetic ducts for safety reasons and to protect the optics against the environment. A...

  15. Thirty Meter Telescope astrometry error budget

    Schöck, Matthias; Do, Tuan; Ellerbroek, Brent; Gilles, Luc; Herriot, Glen; Meyer, Leo; Suzuki, Ryuji; Wang, Lianqi; Yelda, Sylvana
    The Thirty Meter Telescope (TMT) with its first-light multi-conjugate adaptive optics system, NFIRAOS, and high-resolution imager, IRIS, is expected to take differential astrometric measurements with an accuracy on the order of tens of micro arcsec. This requires the control, correction, characterization and calibration of a large number of error sources and uncertainties, many of which have magnitudes much in excess of this level of accuracy. In addition to designing the observatory such that very high precision and accuracy astrometric observations are enabled, satisfying the TMT requirements can only be achieved by a careful calibration, observation and data reduction strategy. In...

  16. Results of the NFIRAOS RTC trade study

    Véran, Jean-Pierre; Boyer, Corrine; Ellerbroek, Brent L.; Gilles, Luc; Herriot, Glen; Kerley, Daniel A.; Ljusic, Zoran; McVeigh, Eric A.; Prior, Robert; Smith, Malcolm; Wang, Lianqi
    With two large deformable mirrors with a total of more than 7000 actuators that need to be driven from the measurements of six 60x60 LGS WFSs (total 1.23Mpixels) at 800Hz with a latency of less than one frame, NFIRAOS presents an interesting real-time computing challenge. This paper reports on a recent trade study to evaluate which current technology could meet this challenge, with the plan to select a baseline architecture by the beginning of NFIRAOS construction in 2014. We have evaluated a number of architectures, ranging from very specialized layouts with custom boards to more generic architectures made from commercial...

  17. Strategies to cope with sodium layer profile variations in laser guide star AO systems

    Ellerbroek, Brent L.
    The vertical profile of the mesospheric sodium layer varies significantly on a time scale of one minute. These variations can impact the random and systematic measurement errors of laser guide star Shack-Hartmann wave front sensors, particularly on extremely large telescopes. Sensor performance can be improved by selecting pixel processing weights matched to the sodium layer profile, assuming that the shape of the profile can be measured or estimated in real time. In this paper we describe the magnitude of these effects for the Thirty Meter Telescope AO system NFIRAOS. We review several existing approaches for measuring or estimating the sodium...

  18. Physical, spectral, and dynamical properties of asteroid (107) Camilla and its satellites

    Pajuelo, M.; Dumas, C.
    The population of large 100+ km asteroids is thought to be primordial. As such, they are the most direct witnesses of the early history of our Solar System available. Those among them with satellites allow study of the mass, and hence density and internal structure. We study here the dynamical, physical, and spectral properties of the triple asteroid (107) Camilla from lightcurves, stellar occultations, optical spectroscopy, and high-contrast and high-angular-resolution images and spectro-images. Using 80 positions measured over 15 years, we determine the orbit of its larger satellite, S/2001 (107) 1, to be circular, equatorial, and prograde, with root-mean-square residuals of...

  19. Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

    Anche, Ramya Manjunath; Sen, Asoke Kumar; Anupama, Gadiyara Chakrapani; Sankarasubramanian, Kasiviswanathan; Skidmore, Warren
    An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated for the unvignetted field-of-view and the wavelengths of interest. The model estimates an IP of 1.26% and a CT of 44% at the Nasmyth focus of the telescope at the wavelength of 0.6 μm at field angle zero with the telescope pointing to zenith. Mueller matrices have been estimated for the primary, secondary, and Nasmyth mirrors. It is found that some of the Mueller matrix elements of the...

  20. Optomechanical design of TMT NFIRAOS Subsystems at INO

    Lamontagne, Frédéric; Desnoyers, Nichola; Grenier, Martin; Cottin, Pierre; Leclerc, Mélanie; Martin, Olivier; Buteau-Vaillancourt, Louis; Boucher, Marc-André; Nash, Reston; Lardiére, Olivier; Andersen, David; Atwood, Jenny; Hill, Alexis; Byrnes, Peter W. G.; Herriot, Glen; Fitzsimmons, Joeleff; Véran, Jean-Pierre
    The adaptive optics system for the Thirty Meter Telescope (TMT) is the Narrow-Field InfraRed Adaptive Optics System (NFIRAOS). Recently, INO has been involved in the optomechanical design of several subsystems of NFIRAOS, including the Instrument Selection Mirror (ISM), the NFIRAOS Beamsplitters (NBS), and the NFIRAOS Source Simulator system (NSS) comprising the Focal Plane Mask (FPM), the Laser Guide Star (LGS) sources, and the Natural Guide Star (NGS) sources. This paper presents an overview of these subsystems and the optomechanical design approaches used to meet the optical performance requirements under environmental constraints.

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