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Peter Wizinowich - One of the best experts on this subject based on the ideXlab platform.

  • Innovations and advances in instrumentation at the W. M. Keck Observatory
    Ground-based and Airborne Instrumentation for Astronomy VII, 2018
    Co-Authors: M. Kassis, Peter Wizinowich, Scott Lilley, Sylvain Cetre, James E. Lyke, Sam Ragland, Dwight Chan, Shui Kwok, Tomas Krasuski, Hilton Lewis
    Abstract:

    Since the start of operations in 1993, the twin 10 meter W. M. Keck Observatory telescopes have continued to maximize their scientific impact and to produce transformative discoveries that keep the observing community on the frontiers of astronomical research. Upgraded capabilities and new instrumentation are provided though collaborative partnerships with Caltech and UC instrument development teams. The observatory adapts and responds to the observers’ evolving needs as defined in the observatory’s strategic plan, periodically refreshed in collaboration with the science community. This paper summarizes the performance of recently commissioned infrastructure projects, technology upgrades, and new additions to the suite of instrumentation at the observatory. We will also provide a status of projects currently in the design or development phase, and since we need to keep our eye on the future, we mention projects in exploratory phases that originate from our strategic plan. Recently commissioned projects include telescope control system upgrades, OSIRIS spectrometer and imager upgrades, and deployments of the Keck Cosmic Web Imager (KCWI), the Near-Infrared Echellette Spectrometer (NIRES), and the Keck I Deployable Tertiary Mirror (KIDM3). Under development are upgrades to the NIRSPEC instrument and adaptive optics (AO) system. Major instrumentation in design phases include the Keck Cosmic Reionization Mapper and the Keck Planet Finder. Future instrumentation studies and proposals underway include a Ground Layer Adaptive Optics system, NIRC2 upgrades, the energy sensitive instrument KRAKENS, an integral field spectrograph LIGER, and a laser tomography AO upgrade. Last, we briefly discuss recovering MOSFIRE and its return to science operations.

  • a fiber injection unit for the Keck planet imager and characterizer
    Techniques and Instrumentation for Detection of Exoplanets VIII, 2017
    Co-Authors: Dimitri Mawet, Jacquesrobert Delorme, Nemanja Jovanovic, J K Wallace, Randy Bartos, Peter Wizinowich, Michael P Fitzgerald, Scott Lilley, Garreth Ruane
    Abstract:

    Coupling a high-contrast imaging instrument to a high-resolution spectrograph has the potential to enable the most detailed characterization of exoplanet atmospheres, including spin measurements and Doppler mapping. The high-contrast imaging system serves as a spatial filter to separate the light from the star and the planet while the high-resolution spectrograph acts as a spectral filter, which differentiates between features in the stellar and planetary spectra. The Keck Planet Imager and Characterizer (KPIC) located downstream from the current W. M. Keck II adaptive optics (AO) system will contain a fiber injection unit (FIU) combining a high-contrast imaging system and a fiber feed to Keck’s high resolution infrared spectrograph NIRSPEC. Resolved thermal emission from known young giant exoplanets will be injected into a single-mode fiber linked to NIRSPEC, thereby allowing the spectral characterization of their atmospheres. Moreover, the resolution of NIRSPEC (R = 37,500) is high enough to enable spin measurements and Doppler imaging of atmospheric weather phenomenon. The module will be integrated and tested at Caltech before being transferred to Keck in 2018.

  • LIFT on Keck: analysis of performance and first experimental results
    Adaptive Optics Systems V, 2016
    Co-Authors: C. Plantet, Peter Wizinowich, S. Ragland, Thierry Fusco, Benoit Neichel, B. Femenia, Rachel Rampy
    Abstract:

    Wavefront sensing in the near infrared has become an attractive option with the advent of new low-noise infrared detectors, such as the SAPHIRA (Selex) and RAPID (CEA/Sofradir) APD arrays. The performance improvements obtained with the H2RG-based Keck I near-infrared tip-tilt sensor is motivating the implementation of a near-infrared low-order sensor for Keck II. The recently proposed focal plane sensor algorithm LIFT could fulfill this role. We show here an analysis of performance, demonstrating that LIFT would provide a significant gain (∼ 1 magnitude) over the current tip/tilt sensor at low flux, as well as the first experimental validation of LIFT on Keck with a calibration source.

  • Estimating phase errors from pupil discontinuities from simulated on sky data: examples with VLT and Keck
    2016
    Co-Authors: Masen Lamb, Peter Wizinowich, Carlos Correia, Jean-françois Sauvage, Jean-pierre Véran, David Andersen, Arthur Vigan, Marcos Van Dam, Laurent Mugnier, Charlotte Bond
    Abstract:

    We propose and apply two methods for estimating phase discontinuities for two realistic scenarios on VLT and Keck. The methods use both phase diversity and a form of image sharpening. For the case of VLT, we simulate the `low wind effect' (LWE) which is responsible for focal plane errors in low wind and good seeing conditions. We successfully estimate the LWE using both methods, and show that using both methods both independently and together yields promising results. We also show the use of single image phase diversity in the LWE estimation, and show that it too yields promising results. Finally, we simulate segmented piston effects on Keck/NIRC2 images and successfully recover the induced phase errors using single image phase diversity. We also show that on Keck we can estimate both the segmented piston errors and any Zernike modes affiliated with the non-common path.

  • Laser guide star facility developments at W. M. Keck Observatory
    Adaptive Optics Systems IV, 2014
    Co-Authors: Jason C. Y. Chin, Peter Wizinowich, Scott Lilley, Sylvain Cetre, D. Medeiros, Randy Campbell, James E. Lyke, E. Wetherell, Sam Ragland, Rachel Rampy
    Abstract:

    Laser Guide Star (LGS) facilities for adaptive optics (AO) have been in routine scientific operation on the Keck II and Keck I telescopes since 2004 and 2012, respectively. Two upgrades are currently in process for the Keck II LGS facility: moving the launch of the laser from the side of the Keck telescope to behind the secondary mirror and replacing the existing dye laser with a Raman-fiber amplifier (RFA) laser. Both of these upgrades are on the path to a multi-LGS facility for Keck’s next generation AO (NGAO) system. We will discuss the performance and operations experience with the existing LGS facilities with an emphasis on the newer Keck I LGS facility, the recently implemented Keck II center launch system and its initial on-sky results, the progress on the design and implementation of the new fiber laser, and the plans for a multi-LGS facility for NGAO.

M. Mark Colavita - One of the best experts on this subject based on the ideXlab platform.

  • Interferometric characterization of Keck segment edge errors
    Ground-based and Airborne Telescopes VII, 2018
    Co-Authors: Mitchell Troy, M. Mark Colavita, Gary Chanan, Stephen J. Martinek
    Abstract:

    The Keck telescope segments were manufactured by stressed mirror polishing of large circular pieces of Zerodur that were then cut into hexagons and finished by Ion Beam Figuring (IBF). It has long been believed that this process results in segments with little or no edge effects. As a result, this same general approach is planned for segment manufacturing for the Thirty Meter Telescope (TMT) and the European Extremely Large Telescope (E-ELT). However, recent measurements at the Keck telescope suggest that at least some of the Keck segments have significant aberrations within 60 mm of the edge. These aberrations impact the telescope phasing and the overall telescope image quality. We present interferometric measurements of multiple Keck segments, characterizing the surface errors near the edges over spatial periods from ~5 cm down to ~1 mm. We show that the largest phasing and image quality effects are due to plateaus of unremoved material, left behind after IBF as a result of obscuration by the IBF supports. Apart from these plateaus, the edge quality is relatively good, though not as good as in the segment interiors. Some residual phasing and image quality effects remain, and these are not currently understood.

  • The Keck Interferometer Nuller
    The Astrophysical Journal, 2012
    Co-Authors: Eugene Serabyn, M. Mark Colavita, B. L. Mennesson, Chris D. Koresko, Marc J. Kuchner
    Abstract:

    The Keck Interferometer Nuller (KIN), the first operational separated-aperture infrared nulling interferometer, was designed to null the mid-infrared emission from nearby stars so as to ease the measurement of faint circumstellar emission. This paper describes the basis of the KIN's four-beam, two-stage measurement approach and compares it to the simpler case of a two-beam nuller. In the four-beam KIN system, the starlight is first nulled in a pair of nullers operating on parallel 85 m Keck-Keck baselines, after which cross-combination on 4 m baselines across the Keck apertures is used to modulate and detect residual coherent off-axis emission. Comparison to the constructive stellar fringe provides calibration. The response to an extended source is similar in the two cases, except that the four-beam response includes a term due to the visibility of the source on the cross-combiner baseline?a small effect for relatively compact sources. The characteristics of the dominant null depth errors are also compared for the two cases. In the two-beam nuller, instrumental imperfections and asymmetries lead to a series of quadratic, positive-definite null leakage terms. For the four-beam nuller, the leakage is instead a series of correlation cross-terms combining corresponding errors in each of the two nullers, which contribute offsets only to the extent that these errors are correlated on the timescale of the measurement. This four-beam architecture has allowed a significant (~order of magnitude) improvement in mid-infrared long-baseline fringe-visibility accuracies.

  • Keck Interferometer nuller instrument performance
    Optical and Infrared Interferometry II, 2010
    Co-Authors: M. Mark Colavita, S. Ragland, Eugene Serabyn, R. Millan-gabet, Rachel Akeson
    Abstract:

    The Keck Interferometer combines the two 10 m Keck telescopes as a long baseline interferometer. It is funded by NASA as a joint development among the Jet Propulsion Laboratory, the W. M. Keck Observatory, and the NASA Exoplanet Science Institute. In February 2008, the 10 um nulling mode began a 32 night observing program with three key science teams to perform a survey of nearby stars for exozodiacal dust. This program has recently concluded, and has been followed by nuller observing on a variety of science topics through the standard proposal process. We provide a review and update of the nuller implementation, and describe the data reduction process, including the calibration approach. We then review the technical performance of the instrument based on the full key science data set, including sensitivity and systematic errors. We also provide some summary data on atmospheric effects applicable to the cophasing approach.

  • Keck Interferometer nuller update
    Optical and Infrared Interferometry, 2008
    Co-Authors: M. Mark Colavita, Peter Wizinowich, Andrew J. Booth, E. R. Ligon, Eugene Serabyn, S. Crawford, J. I. Garcia-gathright, B. L. Mennesson, Christopher G. Paine, S. Ragland
    Abstract:

    The Keck Interferometer combines the two 10 m Keck telescopes as a long baseline interferometer, funded by NASA, as a joint development among the Jet Propulsion Laboratory, the W. M. Keck Observatory, and the Michelson Science Center. Since 2004, it has offered an H- and K-band fringe visibility mode through the Keck TAC process. Recently this mode has been upgraded with the addition of a grism for higher spectral resolution. The 10 um nulling mode, for which first nulling data were collected in 2005, completed the bulk of its engineering development in 2007. At the end of 2007, three teams were chosen in response to a nuller key science call to perform a survey of nearby stars for exozodiacal dust. This key science observation program began in Feb. 2008. Under NSF funding, Keck Observatory is leading development of ASTRA, a project to add dual-star capability for high sensitivity observations and dual-star astrometry. We review recent activity at the Keck Interferometer, with an emphasis on the nuller development.

  • Design and Performance of the Keck Angle Tracker
    Advances in Stellar Interferometry, 2006
    Co-Authors: Samuel L. Crawford, M. Mark Colavita, Andrew J. Booth, S. Ragland, E. Hovland
    Abstract:

    The Keck Angle Tracker (KAT) is a key subsystem in the NASA-funded Keck Interferometer at the Keck Observatory on the summit of Mauna Kea in Hawaii. KAT, which has been in operation since the achievement of first fringes in March 2001, senses the tilt of the stellar wavefront for each of the beams from the interferometer telescopes and provides tilt error signals to fast tip/tilt mirrors for high-bandwidth, wavefront tilt correction. In addition, KAT passes low-bandwidth, desaturation offsets to the adaptive optics system of the Keck telescopes to correct for slow pointing drifts. We present an overview of the instrument design and recent performance of KAT in support of the V2 science and nulling observing modes of the Keck Interferometer.

Andrew J. Booth - One of the best experts on this subject based on the ideXlab platform.

  • Keck Interferometer nuller update
    Optical and Infrared Interferometry, 2008
    Co-Authors: M. Mark Colavita, Peter Wizinowich, Andrew J. Booth, E. R. Ligon, Eugene Serabyn, S. Crawford, J. I. Garcia-gathright, B. L. Mennesson, Christopher G. Paine, S. Ragland
    Abstract:

    The Keck Interferometer combines the two 10 m Keck telescopes as a long baseline interferometer, funded by NASA, as a joint development among the Jet Propulsion Laboratory, the W. M. Keck Observatory, and the Michelson Science Center. Since 2004, it has offered an H- and K-band fringe visibility mode through the Keck TAC process. Recently this mode has been upgraded with the addition of a grism for higher spectral resolution. The 10 um nulling mode, for which first nulling data were collected in 2005, completed the bulk of its engineering development in 2007. At the end of 2007, three teams were chosen in response to a nuller key science call to perform a survey of nearby stars for exozodiacal dust. This key science observation program began in Feb. 2008. Under NSF funding, Keck Observatory is leading development of ASTRA, a project to add dual-star capability for high sensitivity observations and dual-star astrometry. We review recent activity at the Keck Interferometer, with an emphasis on the nuller development.

  • Design and Performance of the Keck Angle Tracker
    Advances in Stellar Interferometry, 2006
    Co-Authors: Samuel L. Crawford, M. Mark Colavita, Andrew J. Booth, S. Ragland, E. Hovland
    Abstract:

    The Keck Angle Tracker (KAT) is a key subsystem in the NASA-funded Keck Interferometer at the Keck Observatory on the summit of Mauna Kea in Hawaii. KAT, which has been in operation since the achievement of first fringes in March 2001, senses the tilt of the stellar wavefront for each of the beams from the interferometer telescopes and provides tilt error signals to fast tip/tilt mirrors for high-bandwidth, wavefront tilt correction. In addition, KAT passes low-bandwidth, desaturation offsets to the adaptive optics system of the Keck telescopes to correct for slow pointing drifts. We present an overview of the instrument design and recent performance of KAT in support of the V2 science and nulling observing modes of the Keck Interferometer.

  • The control system for the Keck Interferometer Nuller
    Advances in Stellar Interferometry, 2006
    Co-Authors: Andrew J. Booth, M. Mark Colavita, Jean I. Garcia, Chris D. Koresko
    Abstract:

    The Keck Interferometer links the two 10m Keck Telescopes located atop Mauna Kea in Hawaii. It was the first 10m class, fully AO equipped interferometer to enter operation. Further, it is the first large interferometer to implement a nuller, whereby the on axis light from a bright point source (e.g. a star) can be removed interferometrically, allowing study of light from nearby, low contrast sources (e.g. exo-zodiacal dust). This paper describes the control system we have implemented to enable operation of the Keck interferometer nuller. We give a general overview of the control system, plus details of how control differs from the already implemented and operational, standard visibility science mode of the interferometer. The nuller is challenging in its requirements for control because of the necessary control precision and the complexity of the number of points of control. We have implemented some novel control methods to meet these requirements and we describe those here.

  • The Keck Interferometer Nuller: System Architecture and Laboratory Performance
    New Frontiers in Stellar Interferometry, 2004
    Co-Authors: Eugene Serabyn, M. Mark Colavita, Andrew J. Booth, Richard L. Johnson, Samuel L. Crawford, E. Hovland, Michelle Creech-eakman, Jean I. Garcia, Chris D. Koresko, E. R. Ligon
    Abstract:

    The first high-dynamic-range interferometric mode planned to come on line at the Keck Observatory is mid-infrared nulling. This observational mode, which is based on the cancellation of the on-axis starlight arriving at the twin Keck telescopes, will be used to examine nearby stellar systems for the presence of circumstellar exozodiacal emission. This paper describes the system level layout of the Keck Interferometer Nuller (KIN), as well as the final performance levels demonstrated in the laboratory integration and test phase at the Jet Propulsion Laboratory prior to shipment of the nuller hardware to the Keck Observatory in mid-June 2004. On-sky testing and observation with the mid-infrared nuller are slated to begin in August 2004.

  • Observations of DG tauri with the Keck interferometer
    The Astrophysical Journal, 2003
    Co-Authors: M. Mark Colavita, Peter Wizinowich, Rachel Akeson, M. Shao, S. Acton, J. Beletic, J. Bell, J. Berlin, A. F. Boden, Andrew J. Booth
    Abstract:

    We present the first science results from the Keck Interferometer, a direct-detection infrared interferometer utilizing the two 10 m Keck telescopes. The instrument and system components are briefly described. We then present observations of the T Tauri object DG Tau, which is resolved by the interferometer. The resolved component has a radius of 0.12-0.24 AU, depending on the assumed stellar and extended component fluxes and the model geometry used. Possible origins and implications of the resolved emission are discussed.

William Lupton - One of the best experts on this subject based on the ideXlab platform.

  • Overview of the control system for the Keck Interferometer
    Advanced Telescope and Instrumentation Control Software II, 2002
    Co-Authors: Andrew J. Booth, Richard L. Johnson, Dean L. Palmer, E. Hovland, William Lupton, Leonard J. Reder, Glenn Eychaner, Al Niessner, Andy C. Rudeen, Robert F. Smythe
    Abstract:

    The Keck Interferometer links the two 10m Keck Telescopes located atop Mauna Kea in Hawaii. It is the first 10m class, fully AO equipped interferometer to enter operation. Further, it is the first large interferometer designed to be handed over from a design and implementation team to a separate operations team, and be used by astronomers who are not interferometer specialists. As such it offers unique challenges in reducing an extremely complex and powerful system to an apparently simple user interface, and providing a well engineered system that can be maintained by people who did not develop it. This paper gives an overview of the control system that has been implemented for the single baseline operation of the instrument, and indicates how this will be extended to allow control of the future modes of the instrument (nulling, differential phase and astrometry). The control system has several parts. One is for control of "slow" sub-systems, which is based in the EPICS architecture, already ubiquitous at the Keck Observatory. Another, used to control hard real time sub-systems, is based on a new infrastructure developed at JPL, programmed in C++, Java, and using CORBA for communication. This infrastructure has been developed specifically with the problems of interferometric control in mind and is used in JPL's flight testbeds as well as the Keck Interferometer. Finally, a user interface and high level control layer is in development using a variety of tools including UML based modeling in the Rhapsody tool (using C++ and CORBA), Java, and Tcl/Tk for prototyping.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

  • Chopping secondary mirror control systems for the W. M. Keck Telescopes
    Telescope Control Systems II, 1997
    Co-Authors: William Lupton
    Abstract:

    The Keck 1 chopping secondary was built by the Palo Alto Research Laboratories of the Lockheed (now Lockheed Martin) Missiles and Space Company. The only software component of the delivered system is a proprietary error correction algorithm; Keck wrote software to generate acceleration-limited azimuth and elevation demands, to rotate these demands as a function of telescope position, to interact with the error correction system, and to mange hardware start-up and shutdown. The Keck 2 chopping secondary, also built by Lockheed, was originally conceived as an infrared fast steering mechanism (IFSM) and is simpler than the Keck 1 system, with lower power and acceleration limits and, therefore, lower chop amplitude and frequency specifications. As far as possible, it provides the same external interfaces as the Keck 1 system. A new EPICS- based telescope control system has been written for Keck 2 and was retrofitted on Keck 1 in March 1997. The Keck 1 chopper control software has been converted to the EPICS environment and, at the same time, altered so that the same software supports both choppers. This conversion has retained as much as possible of the complex real-time code of the old system while at the same time fully utilizing EPICS facilities. The paper presents more details of both the old and the new systems and illustrates how the new system is simpler than the old as well as being much better integrated into the overall telescope control system. Operational experience is presented.

  • Keck II Telescope Control System
    Optical Telescopes of Today and Tomorrow, 1997
    Co-Authors: William Lupton, Hilton Lewis, Kevin Tsubota, Allan Honey, Sarah Quady
    Abstract:

    The experimental physics and industrial control system (EPICS) originated in the high energy physics community and has been used for several years to control accelerators. It is now in use or soon to be in use at several observatories around the world. In 1995, it was decided that Keck II telescope would have a new EPICS-based control system rather than use a copy of the Keck I system. This decision was made because it was felt that EPICS provided a superior software infrastructure to that developed for Keck I, and that it would scale well to encompass adaptive optics and eventual use of the two telescopes for interferometry. The new control system was developed throughout 1995 and the early part of 1996, leading to first light in January 1996, making it the first fully EPICS-controlled telescope control system in the world. This paper describes how EPICS has been used to implement the control system, including a detailed discussion of the axes control, pointing and timing system, and of how they interact with each other.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

  • Software infrastructure for the Keck II telescope
    Telescope Control Systems, 1995
    Co-Authors: William Lupton
    Abstract:

    Many diverse software systems are in use on the Keck I telescope. This is mostly because software standards were low-level (e.g., choice of programming language, computer or operating system) and did not specify use of a particular software environment. Selection of directory structures, messaging systems, tasking environments and support packages was largely left up to individual development groups, although there were some successful instances of group collaborations. For the Keck II telescope, a common set of standards and tools has been agreed on, and the provision and maintenance of these tools is regarded as a group effort. These standards and tools are known as the Keck II Software Infrastructure and include EPICS (Experimental Physics and Industrial Control System), the successful Keck I concept of making all system control available via keyword/value pairs, the Tcl command language, standard logging and error reporting, and common programing standards. This paper discusses some of the successes and failures of the Keck I approach and describes how the Keck II system is evolving from the Keck I system. Some examples of the use of EPICS for telescope control are given, and EPICS as a vehicle for future collaboration is considered.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Randy Campbell - One of the best experts on this subject based on the ideXlab platform.

  • Laser guide star facility developments at W. M. Keck Observatory
    Adaptive Optics Systems IV, 2014
    Co-Authors: Jason C. Y. Chin, Peter Wizinowich, Scott Lilley, Sylvain Cetre, D. Medeiros, Randy Campbell, James E. Lyke, E. Wetherell, Sam Ragland, Rachel Rampy
    Abstract:

    Laser Guide Star (LGS) facilities for adaptive optics (AO) have been in routine scientific operation on the Keck II and Keck I telescopes since 2004 and 2012, respectively. Two upgrades are currently in process for the Keck II LGS facility: moving the launch of the laser from the side of the Keck telescope to behind the secondary mirror and replacing the existing dye laser with a Raman-fiber amplifier (RFA) laser. Both of these upgrades are on the path to a multi-LGS facility for Keck’s next generation AO (NGAO) system. We will discuss the performance and operations experience with the existing LGS facilities with an emphasis on the newer Keck I LGS facility, the recently implemented Keck II center launch system and its initial on-sky results, the progress on the design and implementation of the new fiber laser, and the plans for a multi-LGS facility for NGAO.

  • Keck I laser guide star adaptive optics system
    Adaptive Optics Systems III, 2012
    Co-Authors: Jason C. Y. Chin, Peter Wizinowich, Randy Campbell, Liz Chock, Andrew Cooper, Ean James, James E. Lyke, Joe Mastromarino, O. A. Martin, D. Medeiros
    Abstract:

    With the commencement of shared-risk science observations in May 2012, the Keck I laser guide star (LGS) adaptive optics (AO) system is the second LGS AO system to be commissioned at the W. M. Keck Observatory. This paper reports on the Keck I LGS AO system itself and some of the initial performance results. The Keck I system differs from the Keck II system primarily with regards to the laser and a beam transport system which projects the laser from behind the telescope’s secondary mirror. The existing OSIRIS science instrument has been integrated with the Keck I system.

  • osiris a diffraction limited integral field spectrograph for Keck
    New Astronomy Reviews, 2006
    Co-Authors: James E. Larkin, Randy Campbell, Sean M. Adkins, Paola Amico, Matthew Barczys, A Krabbe, Ted Aliado, George Brims, John Canfield, Thomas M Gasaway
    Abstract:

    Abstract We present an overview of the OSIRIS integral field spectrograph which was recently commissioned on the Keck II Telescope. OSIRIS works with the Keck Adaptive Optics system and utilizes an infrared transmissive lenslet array to sample a rectangular field of view at close to the Keck diffraction limit. By packing the spectra very closely together (2 pixel rows per spectrum) and using the Rockwell Hawaii-2 detector (wavelengths between 1 and 2.5 μm), we achieve a relatively large field of view (up to 6.4″) while maintaining full broad-band spectral coverage at a resolution of 3800. Among the challenges of the instrument are: a fully cryogenic design (approximately 250 kg are brought down to 55 K); four spatial scales from 0.02 to 0.10″; extremely low wavefront error (approximately 25 nm of non-common path error); large all aluminum optics for the spectrograph; extremely repeatable spectral formats; and a sophisticated data reduction pipeline.

  • the w m Keck observatory laser guide star adaptive optics system overview
    Publications of the Astronomical Society of the Pacific, 2006
    Co-Authors: Peter Wizinowich, Jason C. Y. Chin, Randy Campbell, Marcos A. Van Dam, A. H. Bouchez, Adam R. Contos, Scott K. Hartman, Erik M. Johansson, David Le Mignant, R. Lafon
    Abstract:

    The Keck Observatory began science observations with a laser guide star adaptive optics system, the first such system on an 8-10 m class telescope, in late 2004. This new capability greatly extends the scientific potential of the Keck II Telescope, allowing near-diffraction-limited observations in the near-infrared using natural guide stars as faint as 19th magnitude. This paper describes the conceptual approach and technical implementation followed for this system, including lessons learned, and provides an overview of the early science capabilities.