Science.gov

Sample records for 10-m keck telescope

  1. First Resolved Images of a Spacecraft in Geostationary Orbit with the Keck-II 10 m Telescope

    DTIC Science & Technology

    2010-09-01

    2009, with the adaptive optics on the largest telescope on the planet, the 10 m Keck-II on the 14000 foot summit of Mauna Kea . 1. Observations As...part of an engineering run at the Keck-II 10 m telescope on Mauna Kea , several adaptive optics images were obtained of geostationary satellite GE-23, a...largest telescope on the planet, the 10 m Keck-II on the 14000 foot summit of Mauna Kea . 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17

  2. Wavefront control system for the Keck telescope

    SciTech Connect

    Brase, J. M., LLNL

    1998-03-01

    The laser guide star adaptive optics system currently being developed for the Keck 2 telescope consists of several major subsystems: the optical bench, wavefront control, user interface and supervisory control, and the laser system. The paper describes the design and implementation of the wavefront control subsystem that controls a 349 actuator deformable mirror for high order correction and tip-tilt mirrors for stabilizing the image and laser positions.

  3. Keck Telescope Observations of Externally-Polluted White Dwarfs

    NASA Astrophysics Data System (ADS)

    Zuckerman, Ben M.; NASA, Research was Supported in Part by

    2013-01-01

    Beginning in the late 1990s the Keck telescope and HIRES echelle spectrometer have contributed mightily to investigations of white dwarf photospheres that contain elements heavier than helium that have been accreted from surrounding planetary systems. Today we report new Keck measurements of helium atmosphere (DB and DZ) white dwarfs, of Hyades white dwarfs, and of white dwarfs in binary systems.

  4. Neptune and Titan Observed with Keck Telescope Adaptive Optics

    SciTech Connect

    Max, C.E.; Macintosh, B.A.; Gibbard, S.; Gavel, D.T.; Roe, H.; De Pater, I.; Ghez, A.M.; Acton, S.; Wizinowich, P.L.; Lai, O.

    2000-05-05

    The authors report on observations taken during engineering science validation time using the new adaptive optics system at the 10-m Keck II Telescope. They observe Neptune and Titan at near-infrared wavelengths. These objects are ideal for adaptive optics imaging because they are bright and small, yet have many diffraction-limited resolution elements across their disks. In addition Neptune and Titan have prominent physical features, some of which change markedly with time. They have observed infrared-bright storms on Neptune, and very low-albedo surface regions on Titan, Saturn's largest moon, Spatial resolution on Neptune and Titan was 0.05-0.06 and 0.04-0.05 arc sec, respectively.

  5. Neptune and Titan observed with Keck Telescope adaptive optics

    NASA Astrophysics Data System (ADS)

    Max, Claire E.; Macintosh, Bruce A.; Gibbard, Seran; Gavel, Donald T.; Roe, Henry; de Pater, Imke; Ghez, Andrea M.; Acton, Scott; Wizinowich, Peter L.; Lai, Olivier

    2000-07-01

    We report on observations taken during engineering science validation time using the new adaptive optics system at the 10-m Keck II Telescope. We observed Neptune and Titan at near- infrared wavelengths. These objects are ideal for adaptive optics imaging because they are bright and small, yet have many diffraction-limited resolution elements across their disks. In addition Neptune and Titan have prominent physical features, some of which change markedly with time. We have observed infrared-bright 'storms' on Neptune, and very low- albedo surface regions on Titan, Saturn's largest moon. Spatial resolution on Neptune and Titan was 0.05 - 0.06 and 0.04 - 0.05 arc sec, respectively.

  6. Effect of the Keck telescope`s segmented primary on the performance on the Keck adaptive optics system

    SciTech Connect

    Gavel, D.

    1997-06-01

    The 349 degree of freedom Keck adaptive optics system will be mapped on to the 36 segment Keck primary mirror. Each telescope segment is independently controlled in piston and tilt by an active control system and each segment also has its own set of aberrations. This presents a unique set of problems for the Keck adaptive optics system, not encountered with continuous primaries. To a certain extent the low order segment aberrations, beginning with focus, can be corrected statically by the adaptive optic system. However, the discontinuous surface at the segment edges present special problems in sensing and correcting wavefront with laser guide stars or natural guide stars.

  7. Differential Phase Interferometry with the Keck Telescopes

    NASA Technical Reports Server (NTRS)

    Vasisht, Gautam; Colavita, M. Mark

    2004-01-01

    We summarize the Differential Phase (DP) technique as well as the planned implementation at the Keck Interferometer. Multicolor phase measurements are potentially a powerful astrophysical probe - and can allow ground-based direct detection of extrasolar planets. Better than 0.1 mrad phase measurements in the infrared can allow the Keck Interferometer to detect radiation from the so-called hot-Jupiter or 'Roaster' class of planets. At JPL, we are presently developing and testing instrumentation that will enable these extremely sensitive measurements. First on-sky observations are expected to start in mid-2004. In this article we describe DP and other related techniques, provide an outline of the instrument and present results from preliminary laboratory experiments.

  8. First Comet Impacts Captured by Keck Telescope

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A single infrared image (3.5 microns) of Jupiter showing the bright polar caps and a familiar storm system. The brightest spot in the planet's southern hemisphere is the aftermath of comet fragment A, the dimmer spot at the bottom left is the aftermath of fragment C. Credit: James Graham, Imke de Pater, Mike Brown, Mike Liu, Garrett Jernigan, Marina Fomenkova, Andy Ingersoll, Phil Marcus, W. M. Keck Observatory

  9. Cloud Structures on Neptune Observed with Keck Telescope Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Max, C. E.; Macintosh, B. A.; Gibbard, S. G.; Gavel, D. T.; Roe, H. G.; de Pater, I.; Ghez, A. M.; Acton, D. S.; Lai, O.; Stomski, P.; Wizinowich, P. L.

    2003-01-01

    We report on observations obtained with the adaptive optics system at the 10 m Keck II Telescope during engineering validation and early science observing time for the adaptive optics system. We observed Neptune at near-infrared wavelengths. Angular resolution was 0.05"-0.06", corresponding to a spatial scale of approximately 1000 km at Neptune. We discuss the latitudinal structure of circumferential cloud bands and of compact infrared-bright features seen in the southern hemisphere, as well as their variation with wavelength. We determine the values of I/F (proportional to the ratio of reflected intensity to incident solar flux) in the J and H infrared-wavelength bands, including narrowband filters where there is strong methane absorption. We use the I/F values inside and outside of methane bands to estimate the altitude of clouds responsible for the brightest compact features in the infrared. Our data show that, on two of our four observing dates, the brightest region on Neptune contained highly reflective haze layers located below the tropopause but not deeper than a few bars.

  10. Performance predictions for the Keck telescope adaptive optics system

    SciTech Connect

    Gavel, D.T.; Olivier, S.S.

    1995-08-07

    The second Keck ten meter telescope (Keck-11) is slated to have an infrared-optimized adaptive optics system in the 1997--1998 time frame. This system will provide diffraction-limited images in the 1--3 micron region and the ability to use a diffraction-limited spectroscopy slit. The AO system is currently in the preliminary design phase and considerable analysis has been performed in order to predict its performance under various seeing conditions. In particular we have investigated the point-spread function, energy through a spectroscopy slit, crowded field contrast, object limiting magnitude, field of view, and sky coverage with natural and laser guide stars.

  11. Concept design for seismic upgrade of Keck telescopes

    NASA Astrophysics Data System (ADS)

    Kan, Frank W.; Park, Samuel; Sarawit, Andrew T.; Cranston, P. Graham

    2016-08-01

    On 15 October 2006, a large earthquake damaged both telescopes at W. M. Keck Observatory resulting in weeks of observing downtime. A significant portion of the downtime was attributed to recovery efforts repairing damage to telescope bearing journals, radial pad support structures, and encoder subsystems. To reduce the risk of damage and loss of observing time in future seismic events, we developed a conceptual design for the seismic upgrade of the twin Keck Telescopes. The paper covers the design requirements and constraints for the seismic upgrade, the evaluation method used to check the safety of sensitive components, and the trade-off study used to compare different options and to select the best design. Various design options such as base isolating the structure, strengthening seismic restraints, adding dampers, adding break-away mechanisms, and combinations of these design options are considered in this study. Nonlinear time history analyses are performed to evaluate the performance of the design concepts.

  12. High Resolution Imaging of Satellites with Ground-Based 10-m Astronomical Telescopes

    SciTech Connect

    Marois, C

    2007-01-04

    High resolution imaging of artificial satellites can play an important role in current and future space endeavors. One such use is acquiring detailed images that can be used to identify or confirm damage and aid repair plans. It is shown that a 10-m astronomical telescope equipped with an adaptive optics system (AO) to correct for atmospheric turbulence using a natural guide star can acquire high resolution images of satellites in low-orbits using a fast shutter and a near-infrared camera even if the telescope is not capable of tracking satellites. With the telescope pointing towards the satellite projected orbit and less than 30 arcsec away from a guide star, multiple images of the satellite are acquired on the detector using the fast shutter. Images can then be shifted and coadded by post processing to increase the satellite signal to noise ratio. Using the Keck telescope typical Strehl ratio and anisoplanatism angle as well as a simple diffusion/reflection model for a satellite 400 km away observed near Zenith at sunset or sunrise, it is expected that such system will produced > 10{sigma} K-band images at a resolution of 10 cm inside a 60 arcsec diameter field of view. If implemented, such camera could deliver the highest resolution satellite images ever acquired from the ground.

  13. Adaptive Optics Imaging of Neptune with the W.M. Keck Telescope

    NASA Astrophysics Data System (ADS)

    Macintosh, B.; Max, C. E.; Roe, H.; Gibbard, S.; Gavel, D.; Acton, S.; Lai, O.; Wizinowich, P.; de Pater, I.; Ghez, A.; Baines, K.

    1999-09-01

    We present near-IR images of Neptune with a resolution of 0.05 arcseconds obtained with the new adaptive optics (AO) system at the 10-m W.M. Keck II telescope. The resolution and contrast of these images allows us to fit radiative transfer models to Neptune's clear atmosphere, completely uncontaminated by scattered light from bright storms or bands. We can measure for the first time the precise infrared spatial extent of storm features and calculate their reflectance in broad-band and methane-absorption near-IR bandpasses. The images show many bands and cloud features, and detect a bright southern-hemisphere complex that may be associated with a large dark spot similar to that seen by Voyager. These observations demonstrate that AO on an 8-10 meter telescope is a powerful new tool for studying objects in the outer solar system, surpassing the resolution of the NICMOS instrument on the Hubble Space Telescope by a factor of 2-4. This research was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract W-7405-ENG-48. It was supported in part by NASA grant NRA-97-OSS-04-98-053(R3281). The adaptive optics system on the Keck II telescope was funded by the W.M. Keck foundation under a grant to the California Association for Research in Astronomy, and by NASA.

  14. Nearby active galactic nuclei seen via adaptive optics at the Keck Telescope

    NASA Astrophysics Data System (ADS)

    Max, Claire

    2004-02-01

    In recent years it has become increasingly clear that mergers between galaxies play a critical role in galaxy evolution, in the formation of central black holes, and in the phenomena of active galactic nuclei (AGNs) and quasar activity. The advent of adaptive optics on the new generation of 6-10 m telescopes is making it possible to study nearby AGNs and merging galaxies with spatial resolutions of10 - 100 pc. In this talk I will describe and discuss observations of NGC 6240 and Cygnus A, archetypes of merging disk galaxies and of powerful radiogalaxies respectively. I will make use of infrared observations using the adaptive optics system on the 10-m Keck Telescope, as well as visible-light observations from the Hubble Space Telescope.

  15. Wavefront Reconstruction Methods for a Natural Guide Star Adaptive Optics Application to the Keck Telescope

    NASA Technical Reports Server (NTRS)

    Milman, M.; Needels, L.; Redding, D.

    1994-01-01

    Keck telescope is planning to utilize adaptive optics technology to improve the resolution of the instrument. Telescopes operating in the atmosphere are limited by the seeing conditions at the telescope observational site.

  16. Desing of a Laser Guide Star System for the Keck II Telescope

    SciTech Connect

    Friedman, H.W.; Erbert, G.V.; Kuklo, T.; Thompson, G.R.; Wong, N.J.; Gavel, D.T.; Salmon, J.T.; Feldman, M.

    1997-09-11

    A laser guide star system similar to that deployed at the Lick Observatory has been designed for the Keck II 10 m telescope on Mauna Kea, Hawaii. The subaperature size on the primary is comparable to that at Lick, and at the same observational wavelength centered about the K band, so that the average power requirements of the laser system are also comparable, at about 20 W. One major difference is that the seeing at Mauna Kea is about a factor of two better than at Lick so that the spot diameter requirements are smaller and this can give rise to reduced back scatter resulting from saturation effects in the sodium layer. To reduce the peak flux in the sodium layer and obtain a smaller spot diameter, the output beam diameter has been increased along with the repetition rate of the laser. As with the Lick laser system, a dye laser is pumped by a series of frequency doubled YAG lasers which are remotely located and coupled to the dye laser on the telescope by optical fibers. The laser system has a full set of beam control optics as well as launch telescope and safety systems. A computer system couples the laser system to the User Interface and Supervisory Control system of the main telescope. The laser system is due to be shipped to Keck during the fall of 1997 where it will be integrated with the telescope at Mauna Kea. The Adaptive Optics and Optics Bench systems will be integrated first and be ready for integration with the laser in the summer of 1998. 1 ref., 8 figs.

  17. Remote Observing with the Keck Telescope Using the ACTS Satellite

    NASA Technical Reports Server (NTRS)

    Cohen, Judy; Shopbell, Patrick; Bergman, Larry

    1998-01-01

    As a technical demonstration project for the NASA Advanced Communications Technology Satellite (ACTS), we have implemented remote observing on the 10-meter Keck II telescope on Mauna Kea in Hawaii from the California Institute of Technology campus in Pasadena. The data connection consists of optical fiber networks in Hawaii and California, connecting the end-points to high data rate (HDR) ACTS satellite antennae at JPL in Pasadena and at the Tripler Army Medical Center in Honolulu. The terrestrial fiber networks run the asynchronous transfer mode (ATM) protocol at DS-3 (45 Mbit/sec) speeds, providing ample bandwidth to enable remote observing with a software environment identical to that used for on-site observing in Hawaii. This experiment has explored the data requirements of remote observing with a modern research telescope and large-format detector arrays. While the maximum burst data rates are lower than those required for many other applications (e.g., HDTV), the network reliability and data integrity requirements are critical. As we show in this report, the former issue particularly may be the greatest challenge for satellite networks for this class of application. We have also experimented with the portability of standard TCP/IP applications to satellite networks, demonstrating the need for alternative TCP congestion algorithms and minimization of bit error rates (BER). Reliability issues aside, we have demonstrated that true remote observing over high-speed networks provides several important advantages over standard observing paradigms. Technical advantages of the high-speed network access include more rapid download of data to a user's home institution and the opportunity for alternative communication facilities between members of an observing team, such as audio- and videoconferencing.

  18. Infrared View of Comet Fragment G from W. M. Keck Telescope

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This view of Jupiter shows the plume from the impact of fragment G of Comet Shoemaker-Levy 9. The image was made at infrared wavelenths (2.2 microns) using the 10-meter W. M. Keck Telescope in Hawaii. Credit: Dr. Imke de Pater, Dr. James Graham, Michael Brown, and Michael Liu, University of California, and Dr. Marina Fomenkova, University of California at San Diego, W. M. Keck Observatory.

  19. Speckle interferometric images of (216) Kleopatra from the Keck I Telescope

    NASA Astrophysics Data System (ADS)

    Hammergren, M.; Macintosh, B.; Gibbard, S.; Gavel, D.

    2000-10-01

    We present 0.05-arcsecond resolution near-IR images of the unusual main belt asteroid (216) Kleopatra, obtained via speckle interferometry with the 10-m Keck-I telescope in November 1999. The time series of 22 images cover nearly a full rotation, and clearly resolve the asteroid. The images reveal it to be a single, highly-elongated, dumbbell-shaped body, oriented about 30 degrees from pole-on during the time of our observations. We have performed Hapke photometric modeling of the asteroid's surface, and have constructed a three-dimensional shape model. The shape we have derived for this asteroid is nearly identical to the radar delay-Doppler reconstructions of Ostro et al. (Science 288, 836). While the Ostro et al. observations permit a higher spatial resolution in their modeling, our observations have the virtue of being real spatial images, thus providing independent confirmation of their shape model. Our shape model is also consistent with the stellar occultation results of Dunham (Sky and Telescope 83, 73) and pre-COSTAR HST images reported by Storrs et al. (Icarus 137, 260). Our images also allow us to search for albedo and color variations across the asteroid; no significant heterogeneity is seen. This research was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under contract W-7405-ENG-48.

  20. Adaptive Optics Imaging of Neptune and Titan with the W.M. Keck Telescope

    NASA Astrophysics Data System (ADS)

    Max, C.; Macintosh, B.; Gibbard, S.; Roe, H.; de Pater, I.; Ghez, A.; Acton, S.; Wizinowich, P.; Lai, O.

    1999-12-01

    We present near-IR images of Neptune and Titan with a resolution of 0.05 and 0.04 arc seconds respectively, obtained with the new adaptive optics (AO) system at the 10-m Keck II telescope. The resolution and contrast of these images allows us to fit radiative transfer atmospheric models including latitudinal and longitudinal variations. In the case of Neptune the images show both circumferential bands and bright cloud or storm features. We first model Neptune's clear atmosphere, un- contaminated by scattered light from the bright storms and bands. We can measure for the first time the precise infrared spatial extent of storm features and calculate their reflectance in broad-band and methane-absorption near-IR band-passes. These data allow us to model the changed haze distribution within the storm, relative to the clear atmosphere. In the case of Titan we use a radiative transfer model incorporating fractal haze properties, and are able to separate the contributions of Titan's atmosphere and surface to determine the optical depth of Titan's haze layer and to construct surface albedo maps. We find that Titan's trailing hemisphere is overall very dark, with a surface reflectance <0.05 consistent with the presence of solid or liquid hydrocarbons or perhaps very large-grained ice. The leading hemisphere is brighter, but with dark patches of very low albedo similar to the trailing hemisphere. These observations demonstrate that AO on an 8-10 meter telescope is a powerful new tool for the quantitative study of objects in the outer solar system, surpassing the resolution of the NICMOS instrument on the Hubble Space Telescope by a factor of 2-4. This research was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract W-7405-ENG-48.

  1. First Light Adaptive Optics Images from the Keck II Telescope: A New Era of High Angular Resolution Imagery

    NASA Astrophysics Data System (ADS)

    Wizinowich, P.; Acton, D. S.; Shelton, C.; Stomski, P.; Gathright, J.; Ho, K.; Lupton, W.; Tsubota, K.; Lai, O.; Max, C.; Brase, J.; An, J.; Avicola, K.; Olivier, S.; Gavel, D.; Macintosh, B.; Ghez, A.; Larkin, J.

    2000-03-01

    Adaptive optics (AO) is a technology that corrects in real time for the blurring effects of atmospheric turbulence, in principle allowing Earth-bound telescopes to achieve their diffraction limit and to ``see'' as clearly as if they were in space. The power of AO using natural guide stars has been amply demonstrated in recent years on telescopes up to 3-4 m in diameter. The next breakthrough in astronomical resolution was expected to occur with the implementation of AO on the new generation of large, 8-10 m diameter telescopes. In this paper we report the initial results from the first of these AO systems, now coming on line on the 10 m diameter Keck II Telescope. The results include the highest angular resolution images ever obtained from a single telescope (0.022" and 0.040" at 0.85 and 1.65 μm wavelengths, respectively), as well as tests of system performance on three astronomical targets.

  2. Near-Infrared Spectroscopic Investigation of Neptune's Hazes and Storms at the Keck Telescope

    NASA Astrophysics Data System (ADS)

    Roe, H.; Graham, J. R.; de Pater, I.; Gibbard, S.; Macintosh, B.; Max, C.; Baines, K.; Gilbert, A. M.; McLean, I. S.; Becklin, E. E.; Figer, D. F.; Larkin, J. E.; Levenson, N. A.; Teplitz, H. I.; Wilcox, M. K.; NIRSPEC Team

    1999-09-01

    We present observations of Neptune in the near-infrared (1-5 mu m) obtained with the newly commissioned Near-Infrared Spectrometer (NIRSPEC) at the 10-m W.M. Keck Telescope. The infrared spectrum of Neptune is useful for determining the structure and nature of haze layers and bright 'storm' features in the stratosphere and upper troposphere. Significant variations in atmospheric opacity due to methane and H_2 pressure-induced absorption as a function of wavelength allow selective probing of the atmosphere to different depths. Most infrared filters used in imaging cover too wide a spectral range to precisely determine the vertical distribution of hazes and 'storm' particles. Our observations provide both the spatial resolution necessary to separate infrared bright 'storm' features from Neptune's background hazy atmosphere as well as the spectral resolution (R=2000 low-resolution mode, R=25000 high-resolution mode) to selectively probe the atmosphere as a function of altitude. We compare our observed spectra with radiative transfer models to derive haze and 'storm' particle number density and their vertical distribution.

  3. High-Resolution Infrared Imaging of Neptune from the Keck Telescope

    NASA Astrophysics Data System (ADS)

    Gibbard, S. G.; Roe, H.; de Pater, I.; Macintosh, B.; Gavel, D.; Max, C. E.; Baines, K. H.; Ghez, A.

    2002-03-01

    We present results of infrared observations of Neptune from the 10-m W. M. Keck I Telescope, using both high-resolution (0.04 arcsecond) broadband speckle imaging and conventional imaging with narrowband filters (0.6 arcsec resolution). The speckle data enable us to track the size and shape of infrared-bright features ("storms") as they move across the disk and to determine rotation periods for latitudes -30 and -45°. The narrowband data are input to a model that allows us to make estimates of Neptune's stratospheric haze abundance and the size of storm features. We find a haze column density of ˜10 6 cm -2 for a haze layer located in the stratosphere, and a lower limit of 10 7 cm -2 and an upper limit of 10 9 cm -2 for a layer of 0.2 μm particles in the troposphere. We also calculate a lower limit of 7×10 6 km 2 for the size of a "storm" feature observed on 13 October 1997.

  4. Experimental Verification of Dispersed Fringe Sensing as a Segment Phasing Technique using the Keck Telescope

    NASA Technical Reports Server (NTRS)

    Shi, Fang; Ohara, Catherine M.; Chanan, Gary; Troy, Mitch; Redding, Dave C.

    2004-01-01

    Dispersed Fringe Sensing (DFS) is an efficient and robust method for coarse phasing of segmented primary mirrors (from a quarter of a wavelength up to the depth of focus of a single segment, typically several tens of microns). Unlike phasing techniques currently used for ground-based segmented telescopes; this makes it particularly well-suited to the phasing of space-borne segmented telescopes, such as the James Webb Space Telescopes (JWST). In this work we validate DFS by using it to measure the pistons of the segments of one of the Keck telescopes; the results agree with those of the Shack-Hartmann based phasing scheme currently in use at Keck to within 2% over a range of initial piston errors of +/-16 microns.

  5. Experimental Verification of Dispersed Fringe Sensing as a Segment Phasing Technique using the Keck Telescope

    NASA Technical Reports Server (NTRS)

    Shi, Fang; Chanan, Gary; Ohara, Catherine; Troy, Mitchell; Redding, David C.

    2004-01-01

    Dispersed fringe sensing (DFS) is an efficient and robust method for coarse phasing of segmented primary mirrors (from one quarter of a wavelength to as much as the depth of focus of a single segment, typically several tens of microns). Unlike phasing techniques currently used for ground-based segmented telescopes, DFS does not require the use of edge sensors in order to sense changes in the relative heights of adjacent segments; this makes it particularly well suited for phasing of space-borne segmented telescopes, such as the James Webb Space Telescope. We validate DFS by using it to measure the piston errors of the segments of one of the Keck telescopes. The results agree with those of the Shack-Hartmann-based phasing scheme currently in use at Keck to within 2% over a range of initial piston errors of +/-16 (mu)m.

  6. The First Diffraction-Limited Images from the W. M. Keck Telescope

    NASA Technical Reports Server (NTRS)

    Matthews, K.; Ghez, A. M.; Weinberger, A. J.; Neugebauer, G.

    1996-01-01

    The first diffraction limited, 0.05s resolution, images on the W. M. Keck Telescope have been obtained at a wavelength of 2.2 micrometers. These images were part of an experiment to test the suitability of the Keck Telescope for speckle imaging. In order to conduct this test, it was necessary to modify the pixel scale of the Keck facility Near Infrared Camera (NIRC) to optimally sample the spatial frequencies made available by the Keck telescope. The design and implementation of the external reimaging optics, which convert the standard fl25 beam from the secondary mirror to fl182, are described here. Techniques for reducing speckle data with field rotation on an alt-az telescope are also described. Three binary stars were observed in this experiment with separations as small as 0.05s. With only 100 frames of data on each, a dynamic range of at least 3.5 mag was achieved in all cases. These observations imply that a companion as faint as 14.5 mag at 2.2 micrometers could be detected around an 11th magnitude point source.

  7. Hubble and Keck Telescope Observations of Active Asteroid 288P/300163 (2006 VW139)

    NASA Astrophysics Data System (ADS)

    Agarwal, Jessica; Jewitt, David; Weaver, Harold; Mutchler, Max; Larson, Stephen

    2016-01-01

    We present Hubble Space Telescope (HST) and Keck 10 m telescope observations of active asteroid 288P/300163 (2006 VW139) taken to examine ejected dust. The nucleus is a C-type object with absolute magnitude HV = 17.0 ± 0.1 and estimated diameter ˜2.6 km (for assumed visual geometric albedo pV = 0.04). Variations in the brightness of the nucleus at the 10%-15% level are significant in both 2011 December and 2012 October but we possess too few data to distinguish variations caused by activity from those caused by rotation. The dust scattering cross-section in 2011 December is ˜40 km2, corresponding to a dust mass ˜9 × 106 kg (88 μm mean particle radius assumed). The FWHM of the debris sheet varies from ˜100 km near the nucleus to ˜1000 km 30″ (40,000 km) east of it. Dust dynamical models indicate ejection speeds between 0.06 and 0.3 m s-1, particle sizes between 10 and 300 μm and an inverse square-root relation between particle size and velocity. Overall, the data are most simply explained by prolonged, low velocity ejection of dust, starting in or before 2011 July and continuing until at least 2011 October. These properties are consistent with the sublimation of near-surface ice aided by centrifugal forces. The high spatial resolution of our HST images (52 km pixel-1) reveals details that remained hidden in previous ground-based observations, such as the extraordinarily small vertical extent of the dust sheet, ejection speeds well below the nucleus escape speed, and the possibility of a binary nucleus.

  8. HUBBLE AND KECK TELESCOPE OBSERVATIONS OF ACTIVE ASTEROID 288P/300163 (2006 VW139)

    SciTech Connect

    Agarwal, Jessica; Jewitt, David; Weaver, Harold; Mutchler, Max; Larson, Stephen

    2016-01-15

    We present Hubble Space Telescope (HST) and Keck 10 m telescope observations of active asteroid 288P/300163 (2006 VW139) taken to examine ejected dust. The nucleus is a C-type object with absolute magnitude H{sub V} = 17.0 ± 0.1 and estimated diameter ∼2.6 km (for assumed visual geometric albedo p{sub V} = 0.04). Variations in the brightness of the nucleus at the 10%–15% level are significant in both 2011 December and 2012 October but we possess too few data to distinguish variations caused by activity from those caused by rotation. The dust scattering cross-section in 2011 December is ∼40 km{sup 2}, corresponding to a dust mass ∼9 × 10{sup 6} kg (88 μm mean particle radius assumed). The FWHM of the debris sheet varies from ∼100 km near the nucleus to ∼1000 km 30″ (40,000 km) east of it. Dust dynamical models indicate ejection speeds between 0.06 and 0.3 m s{sup −1}, particle sizes between 10 and 300 μm and an inverse square-root relation between particle size and velocity. Overall, the data are most simply explained by prolonged, low velocity ejection of dust, starting in or before 2011 July and continuing until at least 2011 October. These properties are consistent with the sublimation of near-surface ice aided by centrifugal forces. The high spatial resolution of our HST images (52 km pixel{sup −1}) reveals details that remained hidden in previous ground-based observations, such as the extraordinarily small vertical extent of the dust sheet, ejection speeds well below the nucleus escape speed, and the possibility of a binary nucleus.

  9. Long wavelength infrared camera (LWIRC): a 10 micron camera for the Keck Telescope

    SciTech Connect

    Wishnow, E.H.; Danchi, W.C.; Tuthill, P.; Wurtz, R.; Jernigan, J.G.; Arens, J.F.

    1998-05-01

    The Long Wavelength Infrared Camera (LWIRC) is a facility instrument for the Keck Observatory designed to operate at the f/25 forward Cassegrain focus of the Keck I telescope. The camera operates over the wavelength band 7-13 {micro}m using ZnSe transmissive optics. A set of filters, a circular variable filter (CVF), and a mid-infrared polarizer are available, as are three plate scales: 0.05``, 0.10``, 0.21`` per pixel. The camera focal plane array and optics are cooled using liquid helium. The system has been refurbished with a 128 x 128 pixel Si:As detector array. The electronics readout system used to clock the array is compatible with both the hardware and software of the other Keck infrared instruments NIRC and LWS. A new pre-amplifier/A-D converter has been designed and constructed which decreases greatly the system susceptibility to noise.

  10. Speckle imaging of volcanic hotspots on Io with the Keck telescope

    NASA Astrophysics Data System (ADS)

    Macintosh, B. A.; Gavel, D.; Gibbard, S. G.; Max, C. E.; Eckart, M.; de Pater, I.; Ghez, A. M.; Spencer, J.

    2003-09-01

    Using speckle imaging techniques on the 10-m W.M. Keck I telescope, we observed near-infrared emission at 2.2 μm from volcanic hotspots on Io in July-August 1998. Using several hundreds of short-exposure images we reconstructed diffraction-limited images of Io on each of three nights. We measured the positions of individual hotspots to ±0.004″ or better, corresponding to a relative positional error of ˜20 km on Io's surface. The sensitivity of normal ground-based images of Io is limited by confusion between overlapping sources; by resolving these multiple points we detected up to 17 distinct hotspots, the largest number ever seen in a single image. During the month-long span of our 1998 observations, several events occurred. Loki was at the end of a long brightening, and we observed it to fade in flux by a factor of 2.8 over the course of one month. At the 3-sigma level we see evidence that Loki's position shifts by ˜100 km. This suggests that the brightening may not have been located at the "primary" Loki emission center but at a different source within the Loki caldera. We also see a bright transient source near Loki. Among many other sources we detect a dim source on the limb of Io at the latitude of Pele; this source is consistent with 2.7% of the thermal emission from the Pele volcano complex being scattered by the Pele plume, which would be the first detection of a plume through scattered infrared hotspot emission.

  11. Tracking Publications Based on Telescope Sharing Among Gemini, Subaru, and Keck

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Tsang, E.; Kamisato, P.

    2012-08-01

    Gemini Observatory, Subaru Telescope and Keck Observatory operate five 8-10 meters telescopes on the summit of Mauna Kea on the Island of Hawaii and Cerro Pachon in Chile. To expand the range of backend instruments available to each observatory, the three institutions began an exchange program in 2005, whereby each observatory provides a fraction of its telescope time to users of the other two observatories in exchange for telescope time on these telescopes for its own user community. Publications resulted from such collaborations would be a good measure of the success of the program. However, identifying these publications can be a challenge as explicit acknowledgement of the exchange programs are often lacking in some publications. We discuss procedures in identifying exchange publications and also perform bibliometric analysis with the resulting publications as a way to measure the productivity and impact of the exchange programs.

  12. Keck Interferometer

    NASA Technical Reports Server (NTRS)

    2003-01-01

    At the summit of Mauna Kea, Hawaii, NASA astronomers have linked the two 10-meter (33-foot) telescopes at the W. M. Keck Observatory. The linked telescopes, which together are called the Keck Interferometer, make up the world's most powerful optical telescope system. The Keck Interferometer will search for planets around nearby stars and study dust clouds around those stars that may hamper future space-based searches for habitable, Earthlike planets. The Keck Interferometer is part of NASA's Origins program, which seeks to answer two fundamental questions: How did we get here? Are we alone?

  13. Tracking Publications Based on Telescope Sharing among Gemini, Subaru, and Keck: An Update

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Tsang, E.; Kamisato, P.

    2015-04-01

    Gemini Observatory, Subaru Telescope, and Keck Observatory collectively operate five 8-10 meters telescopes on the summit of Mauna Kea on the Island of Hawaii and at Cerro Pachon in Chile. The three institutions began a telescope exchange program in 2005 to expand the range of backend instruments available to their respective users. A participating observatory's users can apply for telescope time from the other two observatories through the time exchange program. To measure the success of the program, we collected publications that resulted from the exchange program for the period from 2005 to 2013. Bibliometric analysis was performed on these publications to measure the productivity and impact of the exchange program. This is an enhanced and updated version of the paper presented at the IAU Commission 5 working Group Libraries session in Beijing, 2012.

  14. Interferometric coupling of the Keck telescopes with single-mode fibers.

    PubMed

    Perrin, G; Woillez, J; Lai, O; Guérin, J; Kotani, T; Wizinowich, P L; Le Mignant, D; Hrynevych, M; Gathright, J; Léna, P; Chaffee, F; Vergnole, S; Delage, L; Reynaud, F; Adamson, A J; Berthod, C; Brient, B; Collin, C; Crétenet, J; Dauny, F; Deléglise, C; Fédou, P; Goeltzenlichter, T; Guyon, O; Hulin, R; Marlot, C; Marteaud, M; Melse, B-T; Nishikawa, J; Reess, J-M; Ridgway, S T; Rigaut, F; Roth, K; Tokunaga, A T; Ziegler, D

    2006-01-13

    Here we report successful interferometric coupling of two large telescopes with single-mode fibers. Interference fringes were obtained in the 2- to 2.3-micrometer wavelength range on the star 107 Herculis by using the two Keck 10-meter telescopes, each feeding their common interferometric focus with 300 meters of single-mode fibers. This experiment demonstrates the potential of fibers for future kilometric arrays of telescopes and is the first step toward the 'OHANA (Optical Hawaiian Array for Nanoradian Astronomy) interferometer at the Mauna Kea observatory in Hawaii. It opens the way to sensitive optical imagers with resolutions below 1 milli-arc second. Our experimental setup can be directly extended to large telescopes separated by many hundreds of meters.

  15. Detailed design of a deployable tertiary mirror for the Keck I telescope

    NASA Astrophysics Data System (ADS)

    Prochaska, J. Xavier; Ratliff, Chris; Cabak, Jerry; Tripsas, Alex; Adkins, Sean; Bolte, Michael; Cowley, David; Dahler, Mike; Deich, Will; Lewis, Hilton; Nelson, Jerry; Park, Sam; Peck, Michael; Phillips, Drew; Pollard, Mike; Randolph, Bill; Sandford, Dale; Ward, Jim; Wold, Truman

    2016-07-01

    Motivated by the ever increasing pursuit of science with the transient sky (dubbed Time Domain Astronomy or TDA), we are fabricating and will commission a new deployable tertiary mirror for the Keck I telescope (K1DM3) at the W.M. Keck Observatory. This paper presents the detailed design of K1DM3 with emphasis on the opto- mechanics. This project has presented several design challenges. Foremost are the competing requirements to avoid vignetting the light path when retracted against a sufficiently rigid system for high-precision and repeatable pointing. The design utilizes an actuated swing arm to retract the mirror or deploy it into a kinematic coupling. The K1DM3 project has also required the design and development of custom connections to provide power, communications, and compressed air to the system. This NSF-MRI funded project is planned to be commissioned in Spring 2017.

  16. Long Baseline Nulling Interferometry with the Keck Telescopes: A Progress Report

    NASA Technical Reports Server (NTRS)

    Mennesson, Bertrand; Akeson, R.; Appleby, E.; Bell, J.; Booth, A.; Colavita, M. M.; Crawford, S.; Creech-Eakman, M. J.; Dahl, W.; Fanson, J.; Felizardo, C.; Garcia, J.; Gathright, J.; Herstein, J.; Hovland, E.; Hrynevych, M.; Johansson, E.; Koresko, C.; Mignant, D. Le; Ligon, R.; Millan-Gabet, R.; Moore, J.; Neyman, C.; Palmer, D.; Panteleeva, T.

    2005-01-01

    The Keck Interferometer Nuller (KIN) is one of the major scientific and technical precursors to the Terrestrial Planet Finder Interferometer (TPF-I) mission. KIN's primary objective is to measure the level of exo-zodiacal mid-infrared emission around nearby main sequence stars, which requires deep broad-band nulling of astronomical sources of a few Janskys at 10 microns. A number of new capabilities are needed in order to reach that goal with the Keck telescopes: mid-infrared coherent recombination, interferometric operation in 'split pupil' mode, N-band optical path stabilization using K-band fringe tracking and internal metrology, and eventually, active atmospheric dispersion correction. We report here on the progress made implementing these new functionalities, and discuss the initial levels of extinction achieved on the sky.

  17. Long Baseline Nulling Interferometry with the Keck Telescopes: a Progress Report

    NASA Astrophysics Data System (ADS)

    Mennesson, B.; Akeson, R.; Appleby, E.; Bell, J.; Booth, A.; Colavita, M. M.; Crawford, S.; Creech-Eakman, M. J.; Dahl, W.; Fanson, J.; Felizardo, C.; Garcia, J.; Gathright, J.; Herstein, J.; Hovland, E.; Hrynevych, M.; Johansson, E.; Koresko, C.; Le Mignant, D.; Ligon, R.; Millan-Gabet, R.; Moore, J.; Neyman, C.; Palmer, D.; Panteleeva, T.; Paine, C.; Ragland, S.; Reder, L.; Rudeen, A.; Saloga, T.; Serabyn, E.; Shao, M.; Smythe, R.; Summers, K.; Swain, M.; Tsubota, K.; Tyau, C.; Vasisht, G.; Wizinowich, P.; Woillez, J.

    The Keck Interferometer Nuller (KIN) is one of the major scientific and technical precursors to the Terrestrial Planet Finder Interferometer (TPF-I) mission. KIN's primary objective is to measure the level of exo-zodiacal mid-infrared emission around nearby main sequence stars, which requires deep broad-band nulling of astronomical sources of a few Janskys at 10 microns. A number of new capabilitites are needed in order to reach that goal with the Keck telescopes: mid-infrared coherent recombination, interferometric operation in "split pupil" mode, N-band optical path stabilization using K-band fringe tracking and internal metrology, and eventually, active atmospheric dispersion correction. We report here on the progress made implementing these new functionalities, and discuss the initial levels of extinction achieved on the sky.

  18. Near Infrared Imaging of the Hubble Deep Field with Keck Telescope

    NASA Technical Reports Server (NTRS)

    Hogg, David W.; Neugebauer, G.; Armus, Lee; Matthews, K.; Pahre, Michael A.; Soifer, B. T.; Weinberger, A. J.

    1997-01-01

    Two deep K-band (2.2 micrometer) images, with point-source detection limits of K=25.2 mag (one sigma), taken with the Keck Telescope in subfields of the Hubble Deep Field, are presented and analyzed. A sample of objects to K=24 mag is constructed and V(sub 606)- I(sub 814) and I(sub 814)-K colors are measured. By stacking visually selected objects, mean I(sub 814)-K colors can be measured to very faint levels, the mean I(sub 814)-K color is constant with apparent magnitude down to V(sub 606)=28 mag.

  19. MOSFIRE: First Light and Early Performance on the Keck I Telescope

    NASA Astrophysics Data System (ADS)

    McLean, Ian S.; Steidel, C. C.; Epps, H. W.; Matthews, K.; Konidaris, N.; Kulas, K.; Mace, G. N.; Rudie, G. C.; Trainor, R.

    2013-01-01

    On April 4, 2012 a new instrument obtained “first light” on the Keck I telescope at the W. M. Keck Observatory on Mauna Kea, Hawaii. Known as MOSFIRE, for Multi-Object Spectrometer For Infra-Red Exploration, this much-anticipated machine provides an enormous boost in efficiency and sensitivity for studies of very faint objects, especially when those objects have a high density on the sky, such as faint, distant galaxies. MOSFIRE was designed and developed by a team involving UCLA, Caltech, UC Santa Cruz, the Keck Observatory and several industrial partners. What makes this large vacuum-cryogenic infrared spectrograph (and camera) unique is the ability to select up to 46 individual objects in a field of view of about 6 x 6 minutes of arc on the sky and then record the infrared spectrum of all 46 simultaneously. When a new field is selected, a robotic mechanism inside the instrument reconfigures the distribution of slits in the focal plane in less than 6 minutes. Performance will be illustrated with results from commissioning, which is now complete.

  20. Spatially-resolved K-band Spectra of Neptune from the W.M. Keck Telescope

    NASA Astrophysics Data System (ADS)

    Gibbard, S. G.; de Pater, I.; Martin, S. C.; Roe, H. G.; Macintosh, B. A.; Max, C. E.

    2002-09-01

    We have obtained 2-micron spectra of Neptune using adaptive optics coupled to the NIRSPEC and NIRC2 spectrographs at the 10-meter W.M. Keck 2 Telescope. Spectra were obtained in June 2000 (NIRSPEC) and in August 2002 (NIRC2). The spatial resolving power of adaptive optics allows us to obtain spectra of individual features on the disk of Neptune at a spatial resolution of approximately 1000 km (0.05-0.06 arcseconds). These features include the north polar haze and bright features near the north pole as well as bright features in the southern hemisphere and small bright features in the solar polar region. Radiative transfer modeling allows us to determine the altitude of the various features and thus to obtain a 3-dimensional picture of the structure of Neptune's atmosphere. This research was supported in part under the auspices of the US Department of Energy at Lawrence Livermore National Laboratory, Univ. of Calif. under contract No. W-7405-Eng-48. Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  1. The W. M. Keck Telescope segmented primary mirror active control system

    SciTech Connect

    Jared, R.C.; Arthur, A.A.; Andreae, S.; Biocca, A.; Cohen, R.W.; Fuertes, J.M.; Franck, J.; Gabor, G.; Llacer, J.; Mast, T.; Meng, J.; Merrick, T.; Minor, R.; Nelson, J.; Orayani, M.; Salz, P.; Schaefer, B.; Witebsky, C.

    1989-07-01

    The ten meter diameter primary mirror of the W. M. Keck Telescope is a mosaic of thirty-six hexagonal mirrors. An active control system stabilizes the primary mirror. The active control system uses 168 measurements of the relative positions of adjacent mirror segments and 3 measurements of the primary mirror position in the telescope structure to control the 108 degrees of freedom needed to stabilize the figure and position of the primary mirror. The components of the active control system are relative position sensors, electronics, computers, actuators that position the mirrors, and software. The software algorithms control the primary mirror, perform star image stacking, emulate the segments, store and fit calibration data, and locate hardware defects. We give an overview of the active control system, its functional requirements and test measurements. 12 refs.

  2. Phasing the mirror segments of the Keck telescopes: the broadband phasing algorithm.

    PubMed

    Chanan, G; Troy, M; Dekens, F; Michaels, S; Nelson, J; Mast, T; Kirkman, D

    1998-01-01

    To achieve its full diffraction limit in the infrared, the primary mirror of the Keck telescope (now telescopes) must be properly phased: The steps or piston errors between the individual mirror segments must be reduced to less than 100 nm. We accomplish this with a wave optics variation of the Shack-Hartmann test, in which the signal is not the centroid but rather the degree of coherence of the individual subimages. Using filters with a variety of coherence lengths, we can capture segments with initial piston errors as large as +/-30 microm and reduce these to 30 nm--a dynamic range of 3 orders of magnitude. Segment aberrations contribute substantially to the residual errors of approximately 75 nm.

  3. Spatially-Resolved 2 micron Spectroscopy of Titan from the W.M. Keck Telescope

    NASA Astrophysics Data System (ADS)

    Gibbard, S. G.; de Pater, I.; Macintosh, B. A.; Grossman, A.; Adamkovics, M.

    2003-05-01

    We obtained spectra and images of Titan using the NIRC2 camera and spectrograph at the 10-meter W.M. Keck II Telescope on March 7-8, 2003. The spectra were obtained at K band (1.95-2.92 microns), a region that probes Titan's surface (< 2.10 microns), troposphere (2.11-2.17 microns), and stratosphere (2.17-2.24 microns). Both north/south and east/west slices through Titan at a slit size of 0.04 arcseconds were obtained. The results clearly show Titan's surface heterogeneity as well as considerable differences across the disk in the troposphere. The stratosphere appears quite uniform with latitude except for a distinct enhancement in brightness in the northern hemisphere compared to the rest of the disk; this appears to be due to the presence of northern high-level haze. Although cloud features have recently been detected in the southern hemisphere of Titan by several observers, our images in the broadband K filter as well as a narrowband filter at 2.108 microns that selectively probes Titan's troposphere showed no sign of clouds on March 7-8 2003. Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. This research was supported in part by the STC Program of the National Science Foundation under Agreement No. AST-9876783. This research was supported in part under the auspices of the US Department of Energy at Lawrence Livermore National Laboratory, Univ. of Calif. under contract No. W-7405-Eng-48.

  4. A computer simulation for evaluating the array performance of the 10-m/phi/ 5-element super-synthesis telescope

    NASA Astrophysics Data System (ADS)

    Morita, K.-I.; Ishiguro, M.

    1980-03-01

    The array performance in several successive configurations was examined for the 10-m(phi) 5-element super-synthesis telescope. The number of (u, v) samples was used as a criterion of optimum (u, v) coverages. The optimum solution for a given declination was obtained by a random trial method. The performance was evaluated by computer simulation using model brightness distributions.

  5. Phasing the mirror segments of the Keck telescopes II: the narrow-band phasing algorithm.

    PubMed

    Chanan, G; Ohara, C; Troy, M

    2000-09-01

    In a previous paper, we described a successful technique, the broadband algorithm, for phasing the primary mirror segments of the Keck telescopes to an accuracy of 30 nm. Here we describe a complementary narrow-band algorithm. Although it has a limited dynamic range, it is much faster than the broadband algorithm and can achieve an unprecedented phasing accuracy of approximately 6 nm. Cross checks between these two independent techniques validate both methods to a high degree of confidence. Both algorithms converge to the edge-minimizing configuration of the segmented primary mirror, which is not the same as the overall wave-front-error-minimizing configuration, but we demonstrate that this distinction disappears as the segment aberrations are reduced to zero.

  6. The dusty AGB star RS CrB: first mid-infrared interferometric observations with the Keck telescopes

    NASA Technical Reports Server (NTRS)

    Mennesson, B.; Koresko, C.; Creech-Eakman, M. J.; Serabyn, E.; Colavita, M. M; Akeson, R.; Appleby, E.; Bell, J.; Booth, A.; Crawford, S.; Dahl, W.; Fanson, J.; Felizardo, C.; Garcia, J.; Gathright, J.; Herstein, J.; Hovland, E.; Hrynevych, M.; Johansson, E.; Le Mignant, D.; Ligon, R.; Millan-Gabet, R.; Moore, J.; Neyman, C.; Palmer, D.

    2005-01-01

    We report interferometric observations of the semiregular variable star RS CrB, a red giant with strong silicate emission features. The data were among the first long-baseline mid-infrared stellar fringes obtained between the Keck telescopes, using parts of the new nulling beam combiner.

  7. Plans for a 10-m submillimeter-wave telescope at the South Pole

    NASA Astrophysics Data System (ADS)

    Stark, Antony A.; Carlstrom, John E.; Israel, Frank P.; Menten, Karl M.; Peterson, Jeffrey B.; Phillips, Thomas G.; Sironi, Giorgio; Walker, Christopher K.

    1998-07-01

    A 10 meter diameter submillimeter-wave telescope has been proposed for installation and scientific use at the NSF Amundsen-Scott South Pole Station. Current evidence indicates that the South Pole is the best submillimeter-wave telescope site among all existing or proposed ground-based observatories. Proposed scientific programs place stringent requirements on the optical quality of the telescope design. In particular, reduction of the thermal background and offsets requires an off-axis, unblocked aperture, and the large field of view needed for survey observations requires shaped optics. This mix of design elements is well-suited for large-scale (square degree) mapping of line and continuum radiation from submillimeter-wave sources at moderate spatial resolutions (4 to 60 arcsecond beam size) and high sensitivity (milliJansky flux density levels). The telescope will make arcminute angular scale, high frequency Cosmic Microwave Background measurements from the best possible ground-based site, using an aperture which is larger than is currently possible on orbital or airborne platforms. The telescope design is homologous. Gravitational changes in pointing and focal length will be accommodated by active repositioning of the secondary mirror. The secondary support, consisting of a large, enclosed beam, permits mounting of either a standard set of Gregorian optics, or prime focus instrumentation packages for CMBR studies. A tertiary chopper is located at the exit pupil of the instrument. An optical design with a hyperboloidal primary mirror and a concave secondary mirror provides a flat focal surface. The relatively large classical aberrations present in such an optical arrangement can be small compared to diffraction at submillimeter wavelengths. Effective use of this telescope will require development of large (1000 element) arrays of submillimeter detectors which are background-limited when illuminated by antenna temperatures near 50 K.

  8. Bright features in Neptune on 2013-2015 from ground-based observations with small (40 cm) and large telescopes (10 m)

    NASA Astrophysics Data System (ADS)

    Hueso, Ricardo; Delcroix, Marc; Baranec, Christoph; Sánchez-Lavega, Agustín; María Gómez-Forrellad, Josep; Félix Rojas, Jose; Luszcz-Cook, Statia; de Pater, Imke; de Kleer, Katherine; Colas, François; Guarro, Joan; Goczynski, Peter; Jones, Paul; Kivits, Willem; Maxson, Paul; Phillips, Michael; Sussenbach, John; Wesley, Anthony; Hammel, Heidi B.; Pérez-Hoyos, Santiago; Mendikoa, Iñigo; Riddle, Reed; Law, Nicholas M.; Sayanagi, Kunio

    2015-11-01

    Observations of Neptune over the last few years obtained with small telescopes (30-50 cm) have resulted in several detections of bright features on the planet. In 2013, 2014 and 2015, different observers have repeatedly observed features of high contrast at Neptune’s mid-latitudes using long-pass red filters. This success at observing Neptune clouds with such small telescopes is due to the presence of strong methane absorption bands in Neptune’s spectra at red and near infrared wavelengths; these bands provide good contrast for elevated cloud structures. In each case, the atmospheric features identified in the images survived at least a few weeks, but were essentially much more variable and apparently shorter-lived, than the large convective system recently reported on Uranus [de Pater et al. 2015]. The latest and brightest spot on Neptune was first detected on July 13th 2015 with the 2.2m telescope at Calar Alto observatory with the PlanetCam UPV/EHU instrument. The range of wavelengths covered by PlanetCam (from 350 nm to the H band including narrow-band and wide-band filters in and out of methane bands) allows the study of the vertical cloud structure of this bright spot. In particular, the spot is particularly well contrasted at the H band where it accounted to a 40% of the total planet brightness. Observations obtained with small telescopes a few days later provide a good comparison that can be used to scale similar structures in 2013 and 2014 that were observed with 30-50 cm telescopes and the Robo-AO instrument at Palomar observatory. Further high-resolution observations of the 2015 event were obtained in July 25th with the NIRC2 camera in the Keck 2 10-m telescope. These images show the bright spot as a compact bright feature in H band with a longitudinal size of 8,300 km and a latitudinal extension of 5,300 km, well separated from a nearby bright band. The ensemble of observations locate the structure at -41º latitude drifting at about +24.27º/day or

  9. Near-infrared imaging of FSC 10214+4724 with the W. M. Keck Telescope

    NASA Technical Reports Server (NTRS)

    Matthews, K.; Soifer, B. T.; Nelson, J.; Boesgaard, H.; Graham, J. R.; Harrison, W.; Irace, W.; Jernigan, G.; Larkin, J. E.; Lewis, H.

    1994-01-01

    Near-infrared observations of the z = 2.286 IRAS source FSC 10214+4724, made with the near-infrared camera on the W. M. Keck Telescope, are reported. Deep broad-band images at 2.15 and 1.27 micrometers, and narrow-band images at 2.165 and 2.125 micrometers with 0.6 sec to 0.9 sec seeing show that FSC 10214+4724 consists of at least three distinct components in a compact group of galaxies. The source of the infrared luminosity appears to be in a strongly interacting galaxy that has a luminosity of approximately 100 times that of a present-day L* galaxy. The interaction suggests and 'age' of this galaxy of approximately equal to 10(exp 9) yr. The H-alpha emission is resolved as a source of diameter approximately equal to 5 kpc, suggesting that a starburst contributes to the observed H-alpha emission. There is an excess of objects in the FSC 10214+4724 field that could represent galaxies in an associated cluster.

  10. Mid-Infrared Imaging of Orion BN/KL With Keck I Telescope

    NASA Technical Reports Server (NTRS)

    Gezari, Daniel Y.; Danchi, William C.; Greenhill, Lincoln J.; Varosi, Frank

    2003-01-01

    We present new images of the Orion BN/KL infrared complex at 4.8, 8.0, 8.9,9.9, 10.4, 11.7, 12.5, 17.6, 18.1,20.0 and 22.0 um obtained with the 10-meter Keck I telescope, with typically 0.3 arcsec resolution at 12.5 um. The multi-wavelength observational image data is registered in a stack and a dust emission/extinction model is fitted to the resulting spectrum of each pixel to create a diffraction-limited "image" of the temperature, opacity and luminosity of the emitting dust, as well as the circumstellar and line-of-sight dust extinction. New source structure, temperature, opacity and luminosity detail is seen in the vicinity of IRc2-IRc7. The model results are used to develop a more complete picture of the structure and energetics of the BN/KL, infrared complex.

  11. Mid-Infrared Imaging of Orion BN/KL With Keck I Telescope

    NASA Technical Reports Server (NTRS)

    Oegerle, William (Technical Monitor); Gezari, Daniel; Danchi, William

    2003-01-01

    We present new images of the Orion BN/KL infrared complex at 4.8, 8.0, 8.9, 9.9, 10.4, 11.7, 12.5, 17.6, 18.1, 20.0 and 22.0 microns obtained with the 10-meter Keck I telescope, with typically 0.3 arcsec resolution at 12.5 microns. The multi-wavelength observational image data is registered in a stack and a dust emission/extinction model is fitted to the resulting spectrum of each pixel to create a diffraction-limited "image" of the temperature, opacity and luminosity of the emitting dust, as well as the circumstellar and line-of-sight dust extinction. New source structure, temperature, opacity and luminosity detail is seen in the vicinity of IRc2-IRc7. The model results are used to develop a more complete picture of the structure and energetics of the BN/KL infrared complex.

  12. Adaptive Optics Observations of Titan from the W.M. Keck Telescope

    NASA Astrophysics Data System (ADS)

    Gibbard, S. G.; Macintosh, B.; Max, C. E.; Roe, H.; de Pater, I.; Young, E. F.; McKay, C. P.

    2000-10-01

    Saturn's largest moon Titan is the only satellite in the solar system with a substantial atmosphere. Photolysis of methane creates a hydrocarbon haze in Titan's atmosphere that is opaque to visible light. The new adaptive optics system on the 10-meter W.M. Keck Telescope enables us to observe Titan with a resolution of 0.04 arcseconds, or 20 resolution elements across the disk. By observing at near-infrared wavelengths that are methane band windows, we can see through Titan's hydrocarbon haze to the surface beneath. We will report on adaptive optics images of Titan taken in 1999, including broadband engineering images taken in February, August, and September, and broadband K and narrowband J and H band images taken in October. The narrowband filters have been chosen to selectively probe Titan's surface or atmosphere. Using this data combined with atmospheric modeling, we are able to determine surface Titan's surface albedo and properties of its hydrocarbon haze layer. This research was supported in part by the STC Program of the National Science Foundation under Agreement No. AST-9876783, and in part under the auspices of the US Department of Energy at Lawrence Livermore National Laboratory, Univ. of Calif. under contract No. W-7405-Eng-48.

  13. 2-micron Adaptive Optics Images of Titan from the W.M. Keck Telescope

    NASA Astrophysics Data System (ADS)

    Gibbard, S. G.; Macintosh, B. A.; Max, C. E.; de Pater, I.; Roe, H. G.; Marchis, F.

    2001-12-01

    Saturn's largest moon Titan is the only satellite in the solar system with a substantial atmosphere, which consists mainly of nitrogen and a few percent methane. Photolysis of methane creates a hydrocarbon haze in Titan's atmosphere that is opaque to visible light. However, in the infrared there are `windows' between methane absorption bands in which the surface of Titan can be imaged. We have observed Titan over the period of 1999-2001 using the adaptive optics system on the 10-meter W.M. Keck Telescope. Using adaptive optics allows us to observe Titan with a resolution of 0.04 arcseconds, or approximately 20 resolution elements across the satellite's disk. We will report on adaptive optics images of Titan taken in 1999-2001 at K band (1.95-2.29 microns). The images are enhanced by application of the MISTRAL iterative image deconvolution routine. Using this data combined with atmospheric modeling, we are able to determine Titan's surface albedo at this wavelength and properties of its hydrocarbon haze layer. This research was supported in part by the STC Program of the National Science Foundation under Agreement No. AST-9876783, and in part under the auspices of the US Department of Energy at Lawrence Livermore National Laboratory, Univ. of Calif. under contract No. W-7405-Eng-48.

  14. The 0.9 and 1.3 THz Superconducting HEB Mixer Receiver for the ASTE 10 m Telescope

    NASA Astrophysics Data System (ADS)

    Shiino, T.; Furuya, R.; Soma, T.; Sakai, T.; Watanabe, Y.; Sakai, N.; Jiang, L.; Ohguchi, O.; Maezawa, H.; Yamakura, T.; Yamamoto, S.

    2013-10-01

    We have developed low-noise waveguide-type superconducting hot electron bolometer (HEB) mixers for astronomical observations in the 0.8-1.0 and 1.3-1.5 THz bands, by using a relatively thick NbTiN superconducting film (10.8 nm). The receiver noise temperature of 350 K (DSB) at 0.81 THz and 490 K at 1.475 THz has been achieved. We have built the 0.8-1.0/1.3-1.5 THz dual band heterodyne receiver using these low noise HEB mixers, and have installed it on the ASTE (Atacama Submillimeter Telescope Experiment) 10 m telescope in Chile in 2011. The 13CO emission (J = 8-7 : 0.8813 THz) has successfully been detected toward the Orion A molecular cloud with our HEB mixer receiver.

  15. Issues in the design and optimization of adaptive optics and laser guide stars for the Keck Telescopes

    SciTech Connect

    Max, C.E.; Gavel, D.T.; Olivier, S.S.

    1994-03-01

    We discuss issues in optimizing the design of adaptive optics and laser guide star systems for the Keck Telescope. The initial tip-tilt system will use Keck`s chopping secondary mirror. We describe design constraints, choice of detector, and expected performance of this tip-tilt system as well as its sky coverage. The adaptive optics system is being optimized for wavelengths of I-2.2{mu}m. We are studying adaptive optics concepts which use a wavefront sensor with varying numbers of subapertures, so as to respond to changing turbulence conditions. The goal is to be able to ``gang together`` groups of deformable mirror subapertures under software control, when conditions call for larger subapertures. We present performance predictions as a function of sky coverage and the number of deformable mirror degrees of freedom. We analyze the predicted brightness several candidate laser guide star systems, as a function of laser power and pulse format. These predictions are used to examine the resulting Strehl as a function of observing wavelength and laser type. We discuss laser waste heat and thermal management issues, and conclude with an overview of instruments under design to take advantage of the Keck adaptive optics system.

  16. The Intrinsic Absorber in QSO 2359-1241: Keck and HUBBLE SPACE TELESCOPE Observations

    NASA Astrophysics Data System (ADS)

    Arav, Nahum; Brotherton, Michael S.; Becker, Robert H.; Gregg, Michael D.; White, Richard L.; Price, Trevor; Hack, Warren

    2001-01-01

    We present detailed analyses of the absorption spectrum seen in QSO 2359-1241 (NVSS J235953-124148). Keck HIRES data reveal absorption from 20 transitions arising from He I, Mg I, Mg II, Ca II, and Fe II. Hubble Space Telescope data show broad absorption lines (BALs) from Al III λ1857, C IV λ1549, Si IV λ1397, and N V λ1240. Absorption from excited Fe II states constrains the temperature of the absorber to 2000<~T<~10,000 K and puts a lower limit of 105 cm-3 on the electron number density. Saturation diagnostics show that the real column densities of He I and Fe II can be determined, allowing us to derive meaningful constraints on the ionization equilibrium and abundances in the flow. The ionization parameter is constrained by the iron, helium, and magnesium data to -3.0<~log(U)<~-2.5, and the observed column densities can be reproduced without assuming departure from solar abundances. From comparison of the He I and Fe II absorption features, we infer that the outflow seen in QSO 2359-1241 is not shielded by a hydrogen ionization front and therefore that the existence of low-ionization species in the outflow (e.g., Mg II, Al III, Fe II) does not necessitate the existence of such a front. We find that the velocity width of the absorption systematically increases as a function of ionization and to a lesser extent with abundance. Complementary analyses of the radio and polarization properties of the object are discussed in a companion paper (Brotherton et al.).

  17. NOTE: Titan's Atmosphere in Late Southern Spring Observed with Adaptive Optics on the W. M. Keck II 10-Meter Telescope

    NASA Astrophysics Data System (ADS)

    Roe, Henry G.; de Pater, Imke; Macintosh, Bruce A.; Gibbard, Seran G.; Max, Claire E.; McKay, Chris P.

    2002-05-01

    Using adaptive optics on the W. M. Keck II telescope, we imaged Titan several times during 1999 to 2001 in narrowband near-infrared filters selected to probe Titan's stratosphere and upper troposphere. We observed a bright feature around the south pole, possibly a collar of haze or clouds. Further, we find that solar phase angle explains most of the observed east-west brightness asymmetry of Titan's atmosphere, although the data do not preclude the presence of a "morning fog" effect at small solar phase angle.

  18. Design and performance of a laser guide star system for the Keck II telescope

    SciTech Connect

    Friedman, H. W., LLNL

    1998-05-18

    A laser system to generate sodium-layer guide stars has been designed, built and delivered to the Keck Observatory in Hawaii. The system uses frequency doubled YAG lasers to pump liquid dye lasers and produces 20 W of average power. The design and performance results of this laser system are presented.

  19. Search for the CO-dark Mass in the Central Molecular Zone by using the ASTE 10-m Telescope

    NASA Astrophysics Data System (ADS)

    Tanaka, Kunihiko

    2017-01-01

    Atomic carbon (C0) is one of the most abundant carbon-bearing species in the interstellar molecular gas, and its submillimeter lines are good tracers of low-density molecular clouds which are often dark in CO rotational lines. We present a new map of the central 150 pc region of the Milky Way in the 500 GHz [CI] line, which has been recently obtained with the ASTE 10-m telescope. The [CI] emission is brightest toward the central 5-pc region, where massive GMCs are absent. This [CI]-bright region is approximately centered toward Sgr A*, covering the entire circum-nuclear ring (CND) and the western part of the 50-km/s cloud. The C0/CO abundance ratio is 0.5-2 there, and the highest ratio is observed toward the CND but just outside of the 2-pc ring of dense gas. This discovery may suggest that the CO-dark component occupies a significant fraction of the molecular gas in the circumnuclear region.

  20. Keck interferometer autoaligner

    NASA Astrophysics Data System (ADS)

    van Belle, Gerard T.; Colavita, M. Mark; Ligon, Edgar R., III; Moore, James D.; Palmer, Dean L.; Reder, Leonard J.; Smythe, Robert F.

    2003-02-01

    A key thrust of NASA's Origins program is the development of astronomical interferometers. Pursuing this goal in a cost-effective and expedient manner from the ground has led NASA to develop the Keck Interferometer, which saw first fringes between the twin 10m Keck telescopes in March of 2001. In order to enhance the imaging potential of this facility, and to add astrometric capabilities for the detection of giant planets about nearby stars, four 1.8 m 'outrigger' telescopes may be added to the interferometer. Robust performance of the multi-aperture instrument will require precise alignment of the large number of optical elements found in the six optical beamtrains spread about the observatory site. The requirement for timely and reliable alignments dictated the development of an automatic alignment system for the Keck Interferometer. The autoaligner consists of swing-arm actuators that insert light-emitting diodes on the optical axis at the location of each optical element, which are viewed by a simple fixed-focus CCD camera at the end of the beamtrain. Sub-pixel centroiding is performed upon the slightly out-of-focus target spots using images provided by a frame grabber, providing steering information to the two-axis actuated optical elements. Resulting mirror-to-mirror alignments are good to within 2 arcseconds, and trimming the alignment of a full beamtrain is designed to take place between observations, within a telescope repointing time. The interactions of the autoaligner with the interferometer delay lines and coude trains are discussed in detail. The overall design of the interferometer's autoaligner system is presented, examining the design philosophy, system sequencing, optical element actuation, and subsystem co-alignment, within the context of satisfying performance requirements and cost constraints.

  1. An Adaptive Optics Survey of the Trapezium with the Keck Telescope

    NASA Astrophysics Data System (ADS)

    Patience, J.; Macintosh, B.; Ghez, A. M.

    2000-12-01

    With the Keck adaptive optics system we are constructing the highest angular resolution map of the dense Trapezium region in Orion. These Keck images can resolve binaries down to ~20 AU, covering the critical separation range associated with the peak of the binary distribution. As of October 2000, our survey with 293 overlapping KCam images encompassed an area of 1300 square arcseconds and covered 53 Orion targets. Additional planned observations should increase the Trapezium sample size. Initial results reveal a number of subarcsecond binaries and suggest a companion star fraction that is more similar to the field G-dwarfs and several open clusters rather than the high value measured in the nearest dark cloud star forming regions. These AO images also resolve several proplyds. This research was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract W-7405-ENG-48, and also supported in part by the Center for Adaptive Optics under the STC Program of the National Science Foundation.

  2. Near-infrared images of MG 1131+0456 with the W. M. Keck telescope: Another dusty gravitational lens?

    NASA Technical Reports Server (NTRS)

    Larkin, J. E.; Matthews, K.; Lawrence, C. R.; Graham, J. R.; Harrison, W.; Jernigan, G.; Lin, S.; Nelson, J.; Neugebauer, G.; Smith, G.

    1994-01-01

    Images of the gravitational lens system MG 1131+0456 taken with the near-infrared camera on the W. M. Keck telescope in the J and K(sub s) bands show that the infrared counterparts of the compact radio structure are exceedingly red, with J - K greater than 4.2 mag. The J image reveals only the lensing galaxy, while the K(sub s) image shows both the lens and the infrared counterparts of the compact radio components. After subtracting the lensing galaxy from the K(sub s) image, the position and orientation of the compact components agree with their radio counterparts. The broad-band spectrum and observed brightness of the lens suggest a giant galaxy at a redshift of approximately 0.75, while the color of the quasar images suggests significant extinction by dust in the lens. There is a significant excess of faint objects within 20 sec of MG 1131+0456. Depending on their mass and redshifts, these objects could complicate the lensing potential considerably.

  3. Bispectrum speckle interferometry of the Red Rectangle: Diffraction-limited near-infrared images reconstructed from Keck telescope speckle data

    NASA Astrophysics Data System (ADS)

    Tuthill, P. G.; Men'shchikov, A. B.; Schertl, D.; Monnier, J. D.; Danchi, W. C.; Weigelt, G.

    2002-07-01

    We present new near-infrared (2.1-3.3 mu m) images of the Red Rectangle with unprecedented diffraction-limited angular resolutions of 46-68 mas; 4 times higher than that of the Hubble space telescope and almost a factor of two improvement over the previous 6 m SAO telecope speckle images presented by Men'shchikov et al. (\\cite{Men'shchikov_etal1998}). The new images, which were reconstructed from Keck telescope speckle data using the bispectrum speckle interferometry method, clearly show two bright lobes above and below the optically thick dark lane obscuring the central binary. X-shaped spikes, thought to trace the surface of a biconical flow, change the intensity distribution of the bright lobes, making them appear broadened or with an east-west double-peak in images with the highest resolution. The striking biconical appearance of the Red Rectangle is preserved on scales from 50 mas to 1 arcmin and from the visible (red) to at least 10 mu m, implying that large grains of at least several microns in size dominate scattering. The new images supplement previous 76 mas resolution speckle reconstructions at shorter wavelengths of 0.6-0.8 mu m (Osterbart et al. \\cite{Osterbart_etal1997}) and 0.7-2.2 mu m (Men'shchikov et al. \\cite{Men'shchikov_etal1998}), allowing a more detailed analysis of the famous bipolar nebula. The intensity distribution of the images is inconsistent with a flat disk geometry frequently used to model the bipolar nebulae. Instead, a geometrically thick torus-like density distribution with bipolar conical cavities is preferred. The extent of the bright lobes indicates that the dense torus has a diameter of >~ 100 AU, for an assumed distance of 330 pc. This torus may be the outer reaches of a flared thick disk tapering inwards to the central star, however such a density enhancement on the midplane is not strictly required to explain the narrow dark lane obscuring the central stars.

  4. Keck Interferometer Science: Present and Future

    NASA Technical Reports Server (NTRS)

    Akeson, Rachel L.

    2004-01-01

    The Keck Interferometer is a NASA funded project developed by the Jet Propulsion Laboratory, the William M. Keck Observatory and the Michelson Science Center at the California Institute of Technology. A technical description of the interferometer is given elsewhere in this volume. This paper will discuss the science topics and goals of the Keck Interferometer project, including a brief description of the Key Science projects, the science projects executed to date and the current availability of the interferometer for new projects. The Keck Interferometer Project consists of the Keck-Keck Interferometer, which combines the two Keck lo-meter telescopes on an 85-meter baseline, and the Outrigger Telescopes Project, a proposal to add four to six 1.8-meter telescopes that would work in conjunction with the two Kecks.

  5. VizieR Online Data Catalog: Keck+Magellan survey for LLSs. III. (Prochaska+, 2015)

    NASA Astrophysics Data System (ADS)

    Prochaska, J. X.; O'Meara, J. M.; Fumagalli, M.; Bernstein, R. A.; Burles, S. M.

    2016-01-01

    The sample presented in this manuscript is intended to be a nearly all-inclusive set of Lyman Limit Systems (LLSs) discovered in the high-dispersion (echelle or echellette; R>5000) spectra that we have gathered at the Keck and Magellan telescopes. Regarding Keck, we have examined all of the data obtained by Principal Investigators (PIs) A. M. Wolfe and J. X. Prochaska at the W. M. Keck Observatory through 2012 April, and from PIs Burles, O'Meara, Bernstein, and Fumagalli at Magellan through 2012 July. We also include the Keck spectra analyzed by Penprase et al. (2010, J/ApJ/721/1). We present data obtained at the W. M. Keck and Las Campanas Observatories using the twin 10m Keck I and Keck II telescopes and the twin 6.5m Baade and Clay telescopes. Altogether, we used four spectrometers: (1) the High Resolution Echelle Spectrometer (HIRES); (2) the Echellette Spectrograph and Imager (ESI); (3) the Magellan Inamori Kyocera Echelle (MIKE); and (4) the Magellan Echellette Spectrograph (MagE). Observing logs for the HIRES and MIKE spectra are provided in Tables 1 and 2. (5 data files).

  6. Phasing the segments of the Keck and Thirty Meter Telescopes via the narrowband phasing algorithm: chromatic effects

    NASA Astrophysics Data System (ADS)

    Chanan, Gary; Troy, Mitchell; Raouf, Nasrat

    2016-07-01

    The narrowband phasing algorithm that was originally developed at Keck has largely been replaced by a broad- band algorithm that, although it is slower and less accurate than the former, has proved to be much more robust. A systematic investigation into the lack of robustness of the narrowband algorithm has shown that it results from systematic errors (of order 20 nm) that are wavelength-dependent. These errors are not well-understood at present, but they do not appear to arise from instrumental effects in the Keck phasing cameras, or from the segment coatings. This leaves high spatial frequency aberrations or scattering within 60 mm of the segment edges as the most likely origin of the effect.

  7. Performance results on the laser portion of the Keck laser guide star system

    SciTech Connect

    Cooke, J B; Danforth, P M; Erbert, G V; Feldman, M; Friedman, H W; Gavel, D T; Jenkins, S L; Jones, H E; Kanz, V K; Kuklo, T; Newman, M J; Pierce, E L; Presta, R W; Salmon, J T; Thompson, G R; Wong, N J

    1998-09-29

    The Laser Guide Star (LGS) system for the Keck II, 10 m telescope consists of two separate but interconnected systems, the laser and the adaptive optics bench. The laser portion of the LGSl is a set of five frequency doubled YAG lasers pumping a master oscillator-power amplifier dye chain to produce up to 30 W of 589 p at 26 kHz of tuned light. Presently the laser system has been set up at the Keck facility in Waimea, HI and is undergoing test and evaluation. When it will be set up on the Keck II telescope, the pump lasers, dye master oscillator and associated control equipment will be located on the dome floor and the dye laser amplifiers, beam control system and diagnostics will be mounted directly on the telescope as shown in Fig. 1, Extensive use of fiber optics for both transmission of the oscillator pulse and the pump laser light has been used.

  8. Deep imaging of the field of the z = 4.9 quasar PC 1247+3406, and faint galaxy counts in the K band with the Keck telescope

    NASA Technical Reports Server (NTRS)

    Soifer, B. T.; Matthews, K.; Djorgovski, S.; Larkin, J.; Graham, J. R.; Harrison, W.; Jernigan, G.; Lin, S.; Nelson, J.; Neugebauer, G.

    1994-01-01

    We present deep images in the K(sub s) band of the field of the quasar PC 1247+3406 at z = 4.897, obtained using the near-infrared camera on the W. M. Keck telescope. A number of faint sources have been detected, some of which appear to be quite red. Their nature and redshifts remain uncertain at this time. These data are combined with deep Keck infrared images of five additional fields and present galaxy counts reaching down to K(sub s) = 22 mag, comparable to the deepest K-band surveys to date. The data presented here are in good agreement with the Hawaii Deep Survey and represent the first independent verification of those results. The slope of the log N-log S relation derived from these data agrees well with the Hawaii Deep Survey, while the counts are slightly higher, especially at the faintest levels probed here. This may be due to a presence of groups or clusters around the target objects at high redshifts.

  9. Overview of the Keck Interferometer

    NASA Technical Reports Server (NTRS)

    vanBelle, Gerard

    1999-01-01

    This is a presentation about the Keck Interferometer which is being constructed on top of Mauna Kea, Hawaii. This includes using the world's largest telescopes for optical and near-infrared astronomy, the twin 10 meter Keck telescopes. The two Keck telescopes, in conjunction with four proposed outrigger telescopes, will be used as an interferometer to conduct observations as part of NASA's Origins Program. These observations will address a variety of topics, including the origin and evolution of planetary systems. This presentation reviews the key features of the interferometer, and the specifications of the telescopes that will be used. It shows diagrams of the site, and the basement layout. It also reviews the science for which the interferometer will be used.

  10. Configurable slit-mask unit of the Multi-Object Spectrometer for Infra-Red Exploration for the Keck telescope: integration and tests

    NASA Astrophysics Data System (ADS)

    Spanoudakis, Peter; Giriens, Laurent; Henein, Simon; Lisowski, Leszek; O'Hare, Aidan; Onillon, Emmanuel; Schwab, Philippe; Theurillat, Patrick

    2008-07-01

    A Configurable Slit Unit (CSU) has been developed for the Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) instrument to be installed on the Keck 1 Telescope on Mauna Kea, Hawaii. MOSFIRE will provide NIR multi-object spectroscopy over a field of view of 6.1' x 6.1'. The reconfigurable mask allows the formation of 46 optical slits in a 267 x 267 mm2 field of view. The mechanism is an evolution of a former prototype designed by CSEM and qualified for the European Space Agency (ESA) as a candidate for the slit mask on NIRSpec for the James Webb Space Telescope (JWST). The CSU is designed to simultaneously displace masking bars across the field-of-view (FOV) to mask unwanted light. A set of 46 bar pairs are used to form the MOSFIRE focal plane mask. The sides of the bars are convoluted so that light is prevented from passing between adjacent bars. The slit length is fixed (5.1 mm) but the width is variable down to 200 μm with a slit positioning accuracy of +/- 18 μm. A two-bar prototype mechanism was designed, manufactured and cryogenically tested to validate the modifications from the JWST prototype. The working principle of the mechanism is based on an improved "inch-worm" stepping motion of 92 masking bars forming the optical mask. Original voice coil actuators are used to drive the various clutches. The design makes significant use of flexure structures.

  11. W. M. KECK TELESCOPE CAPTURES THE IMPACT OF COMET SHOEMAKER-LEVY 9 FRAGMENT-R ON JUPITER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    MAUNA KEA, HAWAII Astronomers: Imke de Pater, James R. Graham, Garrett Jernigan University of California, Berkeley with support from Wendy Harrison, Joel Aycock, David Vezie and the staff of the Keck Observatory The movie shows the impact of Fragment-R of Comet Shoemaker-Levy 9 with Jupiter. The impact was observed at near-infrared wavelengths, 2.3 microns. In the beginning of the movie, only part of the Southern hemisphere is visible with two former impact sites. The former impact site of Fragments P and Q appears on the left side. R hits this same spot. The movie covers a timespan of approximately half an hour. At 5:33 UT a first flash is detected just above the impact site, lasting for approximately 20 seconds. A second flash is detected about 20 seconds later, lasting for about a minute. Several minutes later the fireball becomes visible as a bright spot, increasing rapidly in intensity. Within a few minutes it is outshining the entire planet. The rise and fall in intensity takes about 8 minutes.

  12. Keck adaptive optics: control subsystem

    SciTech Connect

    Brase, J.M.; An, J.; Avicola, K.

    1996-03-08

    Adaptive optics on the Keck 10 meter telescope will provide an unprecedented level of capability in high resolution ground based astronomical imaging. The system is designed to provide near diffraction limited imaging performance with Strehl {gt} 0.3 n median Keck seeing of r0 = 25 cm, T =10 msec at 500 nm wavelength. The system will be equipped with a 20 watt sodium laser guide star to provide nearly full sky coverage. The wavefront control subsystem is responsible for wavefront sensing and the control of the tip-tilt and deformable mirrors which actively correct atmospheric turbulence. The spatial sampling interval for the wavefront sensor and deformable mirror is de=0.56 m which gives us 349 actuators and 244 subapertures. This paper summarizes the wavefront control system and discusses particular issues in designing a wavefront controller for the Keck telescope.

  13. Overview of the control system for the Keck Interferometer

    NASA Astrophysics Data System (ADS)

    Booth, Andrew J.; Eychaner, Glenn; Hovland, Erik; Johnson, Richard L., Jr.; Lupton, William; Niessner, Al; Palmer, Dean L.; Reder, Leonard J.; Rudeen, Andy C.; Smythe, Robert F.; Tsubota, Kevin

    2002-12-01

    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.

  14. New developments in instrumentation at the W. M. Keck Observatory

    NASA Astrophysics Data System (ADS)

    Adkins, Sean M.; McLean, Ian S.; Fitzgerald, Michael P.; Larkin, James E.; Lewis, Hilton A.; Martin, Christopher; Mawet, Dimitri; Prochaska, J. X.; Wizinowich, Peter

    2016-08-01

    The W. M. Keck Observatory is committed to maintaining the scientific leadership of our observing community by matching our observers' skills and passions in their fields of astronomical science with a continuing dedication by the Observatory and its collaborators to the development of state of the art instrumentation and systems. Our science driven strategic plan guides these developments and informs our plans for the future. In this paper we describe the performance of recently completed new instruments, instrument upgrades, and infrastructure upgrade projects. We also describe the expected performance of projects currently in the development or construction phases. Projects recently completed include a new laser for the Keck II AO system, the upgrade of the spectrograph detector in the OSIRIS instrument, and the upgrade to the telescope control system on the Keck II telescope. Projects in development include an upgrade to the telescope control system on the Keck I telescope, the blue channel of the Keck Cosmic Web Imager, the red channel of the Keck Cosmic Web Imager, the Keck Planet Finder, a deployable tertiary mirror for the Keck I telescope, an upgrade to the imager of OSIRIS, a major upgrade to the NIRSPEC instrument, and a fiber feed from the Keck II AO system to NIRSPEC.

  15. Paper Productivity of Ground-based Large Optical Telescopes from 2000 to 2009

    NASA Astrophysics Data System (ADS)

    Kim, Sang Chul

    2011-08-01

    We present an analysis of the scientific (refereed) paper productivity of the current largest (diameter>8m) ground-based optical (and infrared) telescopes during the ten-year period from 2000 to 2009. The telescopes for which we have gathered and analysed the scientific publication data are the two 10-m Keck telescopes, the four 8.2-m Very Large Telescopes (VLT), the two 8.1-m Gemini telescopes, the 8.2-m Subaru telescope, and the 9.2-m Hobby-Eberly Telescope (HET). We have analysed the numbers of papers published in various astronomical journals produced by using these telescopes. While the total numbers of papers from these observatories are largest for the VLT, followed by Keck, Gemini, Subaru, and HET, the number of papers produced by each component of the telescopes is largest for Keck, followed by VLT, Subaru, Gemini, and HET. In 2009, each telescope of the Keck, VLT, Gemini, Subaru, and HET observatories produced 135, 109, 93, 107, and 5 refereed papers, respectively. We have shown that each telescope of the Keck, VLT, Gemini, and Subaru observatories is producing 2.1+/-0.9 Nature and Science papers annually and these papers make up 1.7+/-0.8% of all refereed papers produced by using each of those telescopes. Extending this relation, we propose that this ratio of the number of Nature and Science papers to the total number of refereed papers that will be produced by future extremely large telescopes (ELTs) will remain similar. From a comparison of the publication trends of the above telescopes, we suggest that (i) having more than one telescope of the same kind at the same location and (ii) increasing the number of instruments available at the telescope are good ways to maximize the paper productivity.

  16. Every Member of the U.S. Astronomical Community Can Apply for NASA Keck Time

    NASA Astrophysics Data System (ADS)

    Gelino, Dawn M.

    2017-01-01

    NASA time on the W. M. Keck telescopes is open to every member of the U.S. astronomical community. In fact, it is the only way for PIs from non Keck partner institutions to gain access to these two 10 meter telescopes. I will provide information and tips on how to apply for NASA Keck time through the NASA Exoplanet Science Institute (NExScI), as well as how to access public Keck data through the NASA-Keck joint Keck Observatory Archive (KOA).

  17. The Keck Task Library (KTL)

    NASA Technical Reports Server (NTRS)

    Lupton, W. F.; Conrad, A. R.

    1992-01-01

    KTL is a set of routines which eases the job of writing applications which must interact with a variety of underlying sub-systems (known as services). A typical application is an X Window user interface coordinating telescope and instruments. In order to connect to a service, application code specifies a service name--typically an instrument name--and a style, which defines the way in which the application will interact with the service. Two styles are currently supported: keyword, where the application reads and writes named keywords and the resulting inter-task message traffic is hidden; and message, where the application deals directly with messages. The keyword style is intended mainly for user interfaces, and the message style is intended mainly for lower-level applications. KTL applications are event driven: a typical application first connects to all its desired services, then expresses interest in specified events. The application then enters an event dispatch loop in which it waits for events and calls the appropriate service's event-handling routine. Each event is associated with a call-back routine which is invoked when the event occurs. Call-back routines may (and typically do) interact with other sub-systems and KTL provides the means of doing so without blocking the application (vital for X Window user interfaces). This approach is a marriage of ideas culled from the X window, ADAM, Keck instrument, and Keck telescope control systems. A novel feature of KTL is that it knows nothing about any services or styles. Instead it defines a generic set of routines which must be implemented by all services and styles (essentially open(), ioctl(), read(), write(), event(), and close()) and activates sharable libraries at run-time. Services have been implemented (in both keyword and message styles) for HIRES (the Keck high resolution echelle spectrograph built by Lick Observatory), LWS (the Keck long wavelength spectrometer built by UC San Diego), and the Keck

  18. Nulling at the Keck Interferometer

    NASA Technical Reports Server (NTRS)

    Colavita, M. Mark; Serabyn, Gene; Wizinowich, Peter L.; Akeson, Rachel L.

    2006-01-01

    The nulling mode of the Keck Interferometer is being commissioned at the Mauna Kea summit. The nuller combines the two Keck telescope apertures in a split-pupil mode to both cancel the on-axis starlight and to coherently detect the residual signal. The nuller, working at 10 um, is tightly integrated with the other interferometer subsystems including the fringe and angle trackers, the delay lines and laser metrology, and the real-time control system. Since first 10 um light in August 2004, the system integration is proceeding with increasing functionality and performance, leading to demonstration of a 100:1 on-sky null in 2005. That level of performance has now been extended to observations with longer coherent integration times. An overview of the overall system is presented, with emphasis on the observing sequence, phasing system, and differences with respect to the V2 system, along with a presentation of some recent engineering data.

  19. The Control System for the Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Booth, Andrew; Colavita, Mark; Garcia, Jean; Koresko, Chris

    2006-01-01

    This viewgraph presentation reviews the control system for the interferometer nuller for the two Keck 10 meter telescopes. This reviews the control system that was implemented to enable operation of the Keck interferometer nuller. An overview of the control system is included.

  20. The Keck keyword layer

    NASA Technical Reports Server (NTRS)

    Conrad, A. R.; Lupton, W. F.

    1992-01-01

    Each Keck instrument presents a consistent software view to the user interface programmer. The view consists of a small library of functions, which are identical for all instruments, and a large set of keywords, that vary from instrument to instrument. All knowledge of the underlying task structure is hidden from the application programmer by the keyword layer. Image capture software uses the same function library to collect data for the image header. Because the image capture software and the instrument control software are built on top of the same keyword layer, a given observation can be 'replayed' by extracting keyword-value pairs from the image header and passing them back to the control system. The keyword layer features non-blocking as well as blocking I/O. A non-blocking keyword write operation (such as setting a filter position) specifies a callback to be invoked when the operation is complete. A non-blocking keyword read operation specifies a callback to be invoked whenever the keyword changes state. The keyword-callback style meshes well with the widget-callback style commonly used in X window programs. The first keyword library was built for the two Keck optical instruments. More recently, keyword libraries have been developed for the infrared instruments and for telescope control. Although the underlying mechanisms used for inter-process communication by each of these systems vary widely (Lick MUSIC, Sun RPC, and direct socket I/O, respectively), a basic user interface has been written that can be used with any of these systems. Since the keyword libraries are bound to user interface programs dynamically at run time, only a single set of user interface executables is needed. For example, the same program, 'xshow', can be used to display continuously the telescope's position, the time left in an instrument's exposure, or both values simultaneously. Less generic tools that operate on specific keywords, for example an X display that controls optical

  1. Design and Performance of the Keck Angle Tracker

    NASA Technical Reports Server (NTRS)

    Crawford, Samuel L.; Ragland, S.; Booth, A.; Colavita, M. M.; Hovland, E.

    2006-01-01

    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.

  2. Cats: Optical to Near-Infrared Colors of the Bulge and Disk of Two z = 0.7 Galaxies Using Hubble Space Telescope and Keck Laser Adaptive Optics Imaging

    NASA Astrophysics Data System (ADS)

    Steinbring, E.; Melbourne, J.; Metevier, A. J.; Koo, D. C.; Chun, M. R.; Simard, L.; Larkin, J. E.; Max, C. E.

    2008-10-01

    We have employed laser guide star (LGS) adaptive optics (AO) on the Keck II telescope to obtain near-infrared (NIR) images in the Extended Groth Strip deep galaxy survey field. This is a continuation of our Center for Adaptive Optics Treasury Survey program of targeting 0.5 < z < 1 galaxies where existing images with the Hubble Space Telescope (HST) are already in hand. Our AO field has already been imaged by the Advanced Camera for Surveys and the Near Infrared Camera and Multiobject Spectrograph (NICMOS). Our AO images at 2.2 μm (K') are comparable in depth to those from the HST, have Strehl ratios up to 0.4, and full width at half-maximum resolutions superior to that from NICMOS. By sampling the field with the LGS at different positions, we obtain better quality AO images than with an immovable natural guide star. As examples of the power of adding LGS AO to HST data, we study the optical to NIR colors and color gradients of the bulge and disk of two galaxies in the field with z = 0.7. All authors except L.S. are affiliated with the Center for Adaptive Optics.

  3. Two Decades (almost) of Keck Observations of Io

    NASA Astrophysics Data System (ADS)

    De Pater, I.; Davies, A. G.; de Kleer, K.

    2015-12-01

    We have regularly observed Io with the 10-m Keck Telescope since 1998, initially using the speckle imaging technique, and switching to Adaptive Optics techniques when this became available in 2001. In this talk we will discuss several eruptions that we witnessed, and present 20-30 year timelines of thermal emission from Pele, Pillan, Janus Patera, Kanehekili Fluctus, and Loki Patera, updating timelines in recent publications [1, 2] with additional Keck adaptive optics data obtained between 2002 and 2015. These new timelines are the most comprehensive plots ever produced of the volcanic thermal emission variability for these or any other locations on Io, utilizing data from multiple ground- and space-based assets. Our continuing multi-decadal observing program forms the basis for charting the variability of Io's volcanic activity, of great importance for understanding the evolution of the Galilean satellite system, and with the expectation of new missions to the jovian system in the next decade. Acknowledgements: This research is in part supported by NSF grant AST-1313485 to UC Berkeley. AGD is supported by a grant from the NASA OPR Program. References: [1] Davies et al. (2012) Icarus, 221, 466-470. [2] Rathbun and Spencer (2010) Icarus, 209, 625-630.

  4. Keck Adaptive Optics Images of Uranus and Its Rings

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Gibbard, S. G.; Macintosh, B. A.; Roe, H. G.; Gavel, D. T.; Max, C. E.

    2002-12-01

    We present adaptive optic images of Uranus obtained with the 10-m W. M. Keck II telescope in June 2000, at wavelengths between 1 and 2.4 μm. The angular resolution of the images is ˜0.06-0.09″. We identified eight small cloud features on Uranus's disk, four of which were in the northern hemisphere. The latter features are ˜1000-2000 km in extent and located in the upper troposphere, above the methane cloud, at pressures between 0.5 and 1 bar. Our data have been combined with HST data by Hammel et al. (2001, Icarus153, 229-235); the combination of Keck and HST data allowed derivation of an accurate wind velocity profile. Our images further show Uranus's entire ring system: the asymmetric ɛ ring, as well as the three groups of inner rings (outward from Uranus): the rings 6+5+4, α+β, and the η+γ+δ rings. We derived the equivalent I/ F width and ring particle reflectivity for each group of rings. Typical particle albedos are ˜0.04-0.05, in good agreement with HST data at 0.9 μm.

  5. Keck Adaptive Optics Observations of TW Hydrae Association Members

    NASA Astrophysics Data System (ADS)

    Macintosh, B.; Max, C.; Zuckerman, B.; Becklin, E. E.; Kaisler, D.; Lowrance, P.; Weinberger, A.; Christou, J.; Schneider, G.; Acton, S.

    Adaptive optics (AO) on 8-10 m telescopes is an enormously powerful tool for studying young nearby stars. It is especially useful for searching for companions. Using AO on the 10-m W.M. Keck II telescope we have measured the position of the brown dwarf companion to TWA5 and resolved the primary into an 0.055 arcsecond double. Over the next several years follow-up astrometry should permit an accurate determination of the masses of these young stars. We have also re-observed the candidate extrasolar planet TWA6B, but measurements of its motion relative to TWA6A are inconclusive. We are carrying out a search for new planetary or brown dwarf companions to TWA stars and, if current giant planet models are correct, are currently capable of detecting a 1 Jupiter-mass companion at ~1 arcsecond and a 5 Jupiter-mass companion at ~0.5 arcsecon around a typical TWA member.

  6. HST and Keck AO Images of Vortices on Jupiter

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Wong, M.; Luszcz-Cook, S.; Adamkovics, M.; Marcus, P.; Asay-Davis, X.; Conrad, A.; Go, C.

    2009-09-01

    Observations of Jupiter were conducted in April 2006 and May 2008 with both HST (250-890 nm) and the 10-m Keck telescope. On Keck we used the near-infrared camera NIRC2, coupled to the AO system, at 1.2 to 5 micrometers. At 5 um we are sensitive to Jupiter's thermal emission in cloud-free regions of the atmosphere, while at 1.2 um we see reflected sunlight from hazes and clouds in the troposphere-stratosphere. All small ovals (i.e., all except for Oval BA and the GRS) appear to be surrounded by bright rings at 5 mu, with typical brightness temperatures of 225-250 K, and hence probing depths to 2.5-4 bar. We argue that the small vortices are columnar structures, extending down into the water cloud. Air is rising along the center of these vortices, and descending around the outer periphery; the storm systems are likely fueled by the latent heat released from the water cloud. The descending part of the vertical circulation in the larger ovals is within the ovals, likely at the location of the red ring in Oval BA, which may indicate the maximum radial distance where such return flows can take place. On 19 July 2009, amateur observer Anthony Wesley (Australia) reported a dark spot/streak on Jupiter, near a southern latitude of 56 deg, which he attributed to an impact (analogous to the SL9 impact on Jupiter). We are scheduled to observe Jupiter with the Keck AO system on 24 July 2009 UT; if observations are successful, we will report preliminary results.

  7. Keck Infrared Observations of Jupiter's Ring System

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Graham, J. R.; Liu, M. C.; Showalter, M. R.; Burns, J. A.; Nicholson, P. D.; Hamilton, D. P.

    1998-09-01

    We imaged the Jovian ring system at a wavelength of 2.27 mu m with the 10-m W.M. Keck telescope in August and October 1997, when the ring plane was almost edge-on. We obtained the first images of the Jovian halo and gossamer ring in back-scattered light, and the best ground-based images to date of Jupiter's main ring. The main ring is radially confined between 1.70 -- 1.82 R_J, with a maximum (after inversion) at 1.79 R_J, in agreement with the Voyager findings (1 R_J=71398 km). The halo extends inwards from the main ring (at 1.71 R_J) down to 1.40 R_J, bounded by the locations of Lorentz resonances. Roughly 50% of the halo's intensity originates from a region within ~ 700 km from the equatorial plane, while the halo is visible up to ~ 10,000 km above and below the plane. Although the vertical extent agrees with Voyager findings, the halo's intensity relative to that of the main ring in the Keck images is much less than in Voyager images, which is attributed to the fact that the halo contains fewer macroscopic particles, which preferentially backscatter visible light. The gossamer ring is found to have two components, with steep dropoffs in brightness at the orbits of Amalthea and Thebe. The first, Amalthea's gossamer ring, is visible between the main ring's periphery and ~ 2.5 R_J; it is relatively uniform in brightness and has a vertical thickness (FWHM) of 0.06 R_J, clearly broader than the FWHM of the main ring (0.045 R_J) and image resolution of 0.6('') =0.025;R_J. The other component, a factor of five fainter than Amalthea's ring and about twice as broad vertically (FWHM ~ 0.12 ; R_J), is seen inwards from 3.11 R_J, i.e., inwards of Thebe's orbit. Additional material still seems present, albeit barely, at larger distances, until ~ 3.6 R_J, near the edge of our images. Our data are consistent with the Galileo results, and suggest the ring material originates at the bounding satellites Thebe, Amalthea, Adrastea and Metis (see abstracts by Burns et al., and

  8. The Confirmation and Characterization of the Highest Redshift Galaxies: The Power of Complementary Observations by Keck, Spitzer and Hubble.

    NASA Astrophysics Data System (ADS)

    Illingworth, Garth D.

    2017-01-01

    Extraordinary numbers of high-redshift galaxies have been detected in deep Hubble imaging over the last ~20-yrs. While much is learned from the images, spectroscopy holds the key to both confirming their redshifts and to characterizing their astrophysical properties. The faintness of the galaxies requires our biggest telescopes and high-throughput instruments to do such spectroscopy, and many such combinations are now available on 8-10 m class telescopes. This talk will largely concentrate on Keck's role given the focus of this special session. Since the HDF in 1995 and the HUDF and GOODS in 2003-4, Keck and its powerful optical instruments such as LRIS and DEIMOS have played a major role in spectroscopic studies. With the advent of the WFC3/IR in 2009 and near-IR imaging of fields such as HUDF09, CANDELS and HUDF12 between 2009-and 2012, not only were greater insights for z~1-6 galaxies enabled, but whole new opportunities were opened up for the detection of large samples of galaxies in the first billion years at z>6. The recognition that Spitzer could measure galaxies in the IR well into the confusion-limited regime also resulted in much enhanced datasets on the most distant galaxies. Keck soon was positioned to take advantage of these new higher redshift sources with instruments such as MOSFIRE. The result was a series of detections of the highest redshift galaxies. I will discuss the role that Keck spectroscopy has played in pushing the spectroscopic frontiers for high-redshift galaxies and highlight the synergies that have resulted from Hubble, Spitzer and Keck observations.

  9. Keck Interferometer Nuller science highlights

    NASA Astrophysics Data System (ADS)

    Mennesson, Bertrand; Millan-Gabet, Rafael; Colavita, M. M.; Serabyn, E.; Hinz, P.; Kuchner, M.; Liu, W.; Barry, R.; Stark, C.; Ragland, S.; Woillez, J.; Traub, W.; Absil, O.; Defrère, Denis; Augereau, J. C.; Lebreton, J.

    2012-07-01

    We report here on some of the major astronomical observations obtained by the Keck Interferometer Nuller (KIN), the high dynamic range instrument recombining the Keck Telescopes at wavelengths of 8 to 13 microns. A few science targets were observed during the commissioning phase (2004-2007). These early observations aimed at demonstrating the KIN’s ability to spatially resolve and characterize circumstellar dust emission around a variety of targets, ranging from evolved stars to young debris disks. Science operations started then in 2008 with the more demanding KIN exozodi key science programs, augmented by observations of YSOs and hot debris disks between 2009 and 2011. The last KIN observations were gathered in 2011B, and the interpretation of some of the results depicted here is still preliminary (exo-zodi survey) or pending (complicated behavior observed in YSOs). We discuss in particular the initial results of the KIN’s exo-zodi observations, which targeted a total of 40 nearby main sequence single stars. We look for trends in this sample, searching for possible correlations between the measured KIN excesses and basic stellar properties such as spectral type or the presence of dust inferred from separate observations.

  10. Searching for Faint Exozodiacal Disks: Keck Results and LBTI Status

    NASA Astrophysics Data System (ADS)

    Defrère, D.; Hinz, P.; Mennesson, B.; Millan-Gabet, R.; Skemer, A.; Bailey, V.; Rodigas, T. J.

    2014-01-01

    The possible presence of dust in the habitable zone around nearby main-sequence stars is considered as a major hurdle toward the direct imaging of Earth-like extrasolar planets with future dedicated space-based telescopes (e.g., Roberge et al. 2012). In this context, NASA has funded two ground-based mid-infrared nulling interferometers to combine the large apertures available at the Keck Observatory and the Large Binocular Telescope (LBT). In this poster, we present the preliminary results of the extended survey carried out with the Keck Interferometer Nuller (KIN) between 2008 and 2011 and describe the forthcoming LBTI survey.

  11. The Keck Interferometer Nuller: System Architecture and Laboratory Performance

    NASA Technical Reports Server (NTRS)

    Serabyn, E.; Booth, A.; Colavita, M. M.; Creech-Eakman, M.; Crawford, S.; Garcia, J.; Johnson, R.; Hovland, E.; Koresko, C.; Ligon, R.; Martin, S. R.; Mennesson, B.; Moore, J.; Palmer, D.; Paine, C.; Shao, M.; Swain, M.; Smythe, R.; Vasisht, G.

    2004-01-01

    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 win 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.

  12. The Keck interferometer nuller: system architecture and laboratory performance

    NASA Astrophysics Data System (ADS)

    Serabyn, Eugene; Booth, Andrew J.; Colavita, M. M.; Creech-Eakman, Michelle J.; Crawford, Samuel L.; Garcia, Jean; Johnson, Richard L., Jr.; Hovland, Erik; Koresko, C.; Ligon, Edgar R., III; Martin, Stefan R.; Mennesson, Bertrand P.; Moore, James D.; Palmer, Dean L.; Paine, Christopher G.; Shao, Michael; Swain, Mark R.; Smythe, Robert F.; Vasisht, Gautam

    2004-10-01

    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.

  13. THE KECK INTERFEROMETER NULLER

    SciTech Connect

    Serabyn, E.; Mennesson, B.; Colavita, M. M.; Koresko, C.; Kuchner, M. J.

    2012-03-20

    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 ({approx}order of magnitude) improvement in mid-infrared long-baseline fringe-visibility accuracies.

  14. The Keck Keyword Layer

    NASA Astrophysics Data System (ADS)

    Conrad, A. R.; Lupton, W. F.

    1993-01-01

    Each Keck instrument presents a consistent software view to the applications programmer. A set of ``plug compatible'' applications has been developed that can be used with any instrument. Because image capture software uses the same keyword library to collect data for the image header, a given observation can be ``replayed'' by extracting keyword-value pairs from the image header and passing them back to the control system.

  15. The Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Serabyn, E.; Mennesson, B.; Colavita, M. M.; Koresko, C.; Kuchner, M. J.

    2012-01-01

    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 10 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 itellar 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, positivedefinite null leakage terms. For the four-beam nuller, the leakage is instead a series of correlation cross-tenns 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 (approx. order of magnitude) improvement in mid-infrared long-baseline fringe-visibility accuracies.

  16. The Keck Interferometer Nuller

    NASA Astrophysics Data System (ADS)

    Serabyn, E.; Mennesson, B.; Colavita, M. M.; Koresko, C.; Kuchner, M. J.

    2012-03-01

    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.

  17. Characterization of exozodiacal dust with the Keck interferometer, VLTI, and SIM

    NASA Technical Reports Server (NTRS)

    Colavita, Mark

    1998-01-01

    This overview discusses three interferometers for characterization of exozodiacal dust: Keck Interferometer, the Very Large Telescope Interferometer (VLTI), and the Space Interferometry Mission (SIM). The emphasis will be toward the Keck Interferometer, as exozodiacal dust characterization is one of its science requirements.

  18. Keck Near-Infrared AO Observation of Io in 2011

    NASA Astrophysics Data System (ADS)

    Cantrall, C.; De Pater, I.; Nelson, D. M.; Williams, D. A.; de Kleer, K.

    2015-12-01

    We report observation and analysis of 23 distinct hot spots on Io from images taken in November of 2011 on the 10-m W.M. Keck II telescope. The observations were obtained with 8 different near-infrared (1-5 μm) filters, although no hot spots were detected at the smallest wavelength filters of Hc (1.58 μm) and Kc (2.27 μm). The radiant flux of each hot spot at the different wavelengths was found, which allowed for 1-T and 2-T blackbody fits to obtain estimates of the temperature, emission area, and subsequently, the total radiant output. Global maps over a cylindrical coordinate system were also constructed at each wavelength. In general, Io appeared to be fairly quiescent compared to datasets obtained between 2001 and 2010, with no significant outburst at any particular hot spot. Using GIS software it was possible to create surface maps that display the changes in some of the major hot spots observed between 2001 and 2011. The analysis of these maps and comparison to observations at different time periods will help to further construct a timeline of Io's volcanic activity, which will lead to a better understanding of the variations in surface heat flow over time, the global distribution of hot spots, and the style of eruptions.

  19. Operational performance of MOSFIRE with its cryogenic configurable slitmask unit at the W. M. Keck Observatory

    NASA Astrophysics Data System (ADS)

    Kassis, Marc; McLean, Ian S.; Steidel, Charles C.; Matthews, Keith; Lyke, James E.; Rizzi, Luca; Chan, Dwight; Weiss, Jason; Adkins, Sean; Spanoudakis, Peter; Schwab, Philippe; Onillon, Emmanuel; Lisowski, Leszek; Theurillat, Patrick; Chételat, Olivier; Meier, Christophe

    2016-08-01

    The Multi-Object Spectrograph for Infrared Exploration (MOSFIRE) achieved first light on the W. M. Keck Observatory's Keck I telescope on 4 April 2012 and quickly became the most popular Keck I instrument. One of the primary reasons for the instrument's popularity is that it uses a configurable slitmask unit developed by the Centre Suisse d'Electronique et Microtechnique (CSEM SA) to isolate the light from up to 46 objects simultaneously. In collaboration with the instrument development team and CSEM engineers, the Keck observatory staff present how MOSFIRE is successfully used, and we identify what contributed to routine and trouble free nighttime operations.

  20. The Keck Cosmic Web Imager (KCWI): A Powerful New Integral Field Spectrograph for the Keck Observatory

    NASA Astrophysics Data System (ADS)

    Morrissey, Patrick; KCWI Team

    2013-01-01

    The Keck Cosmic Web Imager (KCWI) is a new facility instrument being developed for the W. M. Keck Observatory and funded for construction by the Telescope System Instrumentation Program (TSIP) of the National Science Foundation (NSF). KCWI is a bench-mounted spectrograph for the Keck II right Nasmyth focal station, providing integral field spectroscopy over a seeing-limited field up to 20"x33" in extent. Selectable Volume Phase Holographic (VPH) gratings provide high efficiency and spectral resolution in the range of 1000 to 20000. The dual-beam design of KCWI passed a Preliminary Design Review in summer 2011. The detailed design of the KCWI blue channel (350 to 700 nm) is now nearly complete, with the red channel (530 to 1050 nm) planned for a phased implementation contingent upon additional funding. KCWI builds on the experience of the Caltech team in implementing the Cosmic Web Imager (CWI), in operation since 2009 at Palomar Observatory. KCWI adds considerable flexibility to the CWI design, and will take full advantage of the excellent seeing and dark sky above Mauna Kea with a selectable nod-and-shuffle observing mode. The KCWI team is lead by Caltech (project management, design and implementation) in partnership with the University of California at Santa Cruz (camera optical and mechanical design) and the W. M. Keck Observatory (program oversight and observatory interfaces).

  1. Observing NGC 4151 with the Keck Interferometer

    NASA Technical Reports Server (NTRS)

    Swain, Mark R.

    2004-01-01

    Observations of the nucleus of NGC 4151 at 2.2 microns using the two 10-meter Keck telescopes as an interferometer show a marginally resolved source less than or equal to 0.1 pc in diameter. These observations are the first measurement of an extragalactic source with an optical/IR interferometer. These observations represent a ten-fold improvement in angular resolution when compared to previous near-infrared measurements of AGN and make it possible to test the subparsecscale, near-infrared emission models of NGC 4151.

  2. PHOTOMETRICALLY TRIGGERED KECK SPECTROSCOPY OF FERMI BL LACERTAE OBJECTS

    SciTech Connect

    Shaw, Michael S.; Romani, Roger W.

    2013-11-01

    We report on Keck spectra of 10 Fermi blazars. J0622+3326, previously unobserved, is shown to be a flat-spectrum radio quasar at redshift z = 1.062. The others are known BL Lac type objects that have resisted previous attempts to secure redshifts. Using a photometric monitoring campaign with the 0.76 m Katzman Automatic Imaging Telescope at Lick Observatory, we identified epochs when the relativistic jet emission was fainter than usual, thus triggering the Keck spectroscopy. This strategy gives improved sensitivity to stars and ionized gas in the host galaxy, thereby providing improved redshift constraints for seven of these sources.

  3. KPF: Keck Planet Finder

    NASA Astrophysics Data System (ADS)

    Gibson, Steven R.; Howard, Andrew W.; Marcy, Geoffrey W.; Edelstein, Jerry; Wishnow, Edward H.; Poppett, Claire L.

    2016-08-01

    KPF is a fiber-fed, high-resolution, high-stability spectrometer in development at the UC Berkeley Space Sciences Laboratory for the W.M. Keck Observatory. The instrument is designed to characterize exoplanets via Doppler spectroscopy with a single measurement precision of 0.5ms-1 or better, however its resolution and stability will enable a wide variety of astrophysical pursuits. KPF will have a 200mm collimated beam diameter and a resolving power of >80,000. The design includes a green channel (440nm to 590 nm) and red channel (590nm to 850 nm). A novel design aspect of KPF is the use of a Zerodur optical bench, and Zerodur optics with integral mounts, to provide stability against thermal expansion and contraction effects.

  4. The NIRSPEC Data Reduction Pipeline for the Keck Observatory Archive

    NASA Astrophysics Data System (ADS)

    Tran, Hien D.; Cohen, R.; Mader, J. A.; Colson, A.; Berriman, G. Bruce; Gelino, Christopher R.; KOA Team

    2016-01-01

    The Keck Observatory Archive (KOA), a collaboration between the NASA Exoplanet Science Institute and the W. M. Keck Observatory, serves science and calibration data for all current and retired instruments from the twin Keck Telescopes. In addition to the raw data, we publicly serve quick-look, reduced data products for four instruments (HIRES, LWS, NIRC2 and OSIRIS), so that KOA users can easily assess the quality and scientific content of the data. In this paper we present the design and implementation of the data reduction pipeline (DRP) for the NIRSPEC instrument for use with KOA. We discuss the publicly available reduction packages for NIRSPEC, the challenges encountered when designing this fully automated DRP and the algorithm used to determine wavelength calibration from sky lines. The reduced data products from the NIRSPEC DRP are expected to be available in KOA by mid-2016.

  5. Titan Imagery with Keck AO during and after Probe Entry

    SciTech Connect

    de Pater, I; Adamkovics, M; Bouchez, A H; Brown, M E; Gibbard, S G; Marchis, F; Roe, H G; Schaller, E L; Young, E

    2006-02-03

    We present adaptive optics data from the 10-m W.M. Keck telescope that were taken during the time the Huygens probe descended through Titan's atmosphere, and on the days following touch-down. The spatial resolution of the images is typically {approx}0.04-inch, or {approx}240 km on Titan (60 km/pixel). No probe entry signal was detected at levels exceeding 0.8 {micro}Jy (3-{sigma}) per pixel (0.01-inch), which although within the range of predicted flux levels, cannot constrain any models. We present data on Titan's surface, troposphere and stratosphere during the days following probe entry, when the solar phase angle varied from 0.05{sup o} up to 0.8{sup o}, with the Sun in the West. Contrary to expectation, the data often showed the East side to be brightest. Adding data obtained with Keck and Gemini over the past few years reveals that the East-West asymmetry can be explained by a combination of the solar phase angle effect together with a general preponderance of haze on Titan's East or morning hemisphere. The troposphere was characterized by quiescent weather; only a few small clouds were present near the south pole, at typical altitudes of 30-40 km. While stratospheric haze was prominent over the northern hemisphere, tropospheric haze dominated the south, from the S. pole up to latitudes of {approx} -45{sup o}. An intriguing observation is that obtained at 1.22 {micro}m, which revealed haze in the form of a collar at -60{sup o}, in contrast to the polar haze cap as usually seen. A comparison of narrow band JHK images of Titan's surface with that obtained by Cassini ISS shows a striking resemblance in small-scale features. After a decent attempt to remove the atmosphere from the images, the surface contrast between dark and bright areas may be larger at 2 {micro}m than at 1.6 and 1.3 {micro}m. If true, this could imply that the dark areas on Titan's surface are covered by a coarser grained frost than the bright areas, and/or that there are more absorbers, such

  6. Keck observations of eruptions on Io in 2003-2005

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Davies, Ashley Gerard; Marchis, Franck

    2016-08-01

    We report observations of four energetic volcanic eruptions on Io: at Tupan Patera on UT 8 March 2003; Tung Yo Patera on UT 28 May 2004; Sui Jen Patera on UT 30 May 2004; and south of Babbar Patera on UT 31 May 2005. The Tung Yo, Sui Jen and south of Babbar Paterae eruptions are in locations where no activity had been seen before. Our observations were obtained at near-infrared wavelengths (1.2-4.7 μm) with the 10-m Keck telescope equipped with adaptive optics. We report single and two-temperature blackbody fits, as well as single-component and dual-component Io Flow Model (IFM) fits (Davies, 1996, Icarus, 124, 45-61) to all four eruptions where applicable. We use 2-μm and 5-μm radiant fluxes, the 2:5-μm radiant flux ratio, and radiant flux density of each thermal source to constrain the likely style of volcanic eruption. All eruptions are characterized by a high temperature IFM component (ranging from 1475 to ∼900 K) from a relatively small area (<1 km2 to several tens of km2), and a lower temperature component with a more extensive surface area. The relationship of the areas at the highest temperatures to the cooler, more extensive area is of particular importance in deriving eruption style. Model fits to the Sui Jen Patera data are strongly suggestive of lava fountaining, although not at a level consistent with a large "outburst" eruption. Activity at Tupan Patera suggests that the entire floor of the patera may have been resurfaced with silicate lava in 2003.

  7. Keck Observations of Dusty Rings in our Solar System

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2007-08-01

    All four giant planets are surrounded by ring systems, which typically consist of a combination of large and small bodies, as well as fine dust. With the 10-m W.M. Keck telescope on Mauna Kea (Hawaii) we have focused on observing the dusty rings of these planets. In this review I will summarize our data sets. I will focus on our most recent results with regard to Jupiter and Uranus, both observed during ring plane crossings. Jupiter's ring system was observed in December 2002 and January 2003 at 2.2 micron, where we used both the facility near-infrared camera NIRC with a pixel size of 0.151" (˜500 km at Jupiter), and the adaptive optics camera NIRC2, with a pixelsize of 0.04" and 0.01". The images were "onion-peeled" to provide radial scans of the rings. We will compare results of the main ring with Galileo data, and comment on similarities and differences with respect to the location of parent material in the ring. The radial structure of the gossamer rings is very different than expected based upon the Burns et al (1999) formation scenarios. The rings are not sheets of material, but narrow rings located just interior to the orbits of Amalthea and Thebe. The Amalthea ring shows a structure analagous to the main ring. Its inner boundary is near the location of synchronous orbit. Radial variations in the Thebe ring suggest "sculpting" by Lorentz resonances. We will present images of Uranus "hot of the press"; we are scheduled to observe in July and August when the rings are edge-on.

  8. Keck observations of the 2002 2003 jovian ring plane crossing

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Showalter, Mark R.; Macintosh, Bruce

    2008-05-01

    We present new observations of Jupiter's ring system at a wavelength of 2.2 μm obtained with the 10-m W.M. Keck telescopes on three nights during a ring plane crossing: UT 19 December 2002, and 22 and 26 January 2003. We used conventional imaging, plus adaptive optics on the last night. Here we present detailed radial profiles of the main ring, halo and gossamer rings, and interpret the data together with information extracted from radio observations of Jupiter's synchrotron radiation. The main ring is confined to a 800-km-wide annulus between 128,200 and 129,000 km, with a ˜5000 km extension on the inside. The normal optical depth is 8×10, 15% of which is provided by bodies with radii a≳5 cm. These bodies are as red as Metis. Half the optical depth, τ≈4×10, is attributed to micron-sized dust, and the remaining τ≈3×10 to grains tens to hundreds of μm in size. The inward extension consists of micron-sized ( a≲10 μm) dust, which probably migrates inward under Poynting-Robertson drag. The inner limit of this extension falls near the 3:2 Lorentz resonance (at orbital radius r=122,400 km), and coincides with the outer limit of the halo. The gossamer rings appear to be radially confined, rather than broad sheets of material. The Amalthea ring is triangularly shaped, with a steep outer dropoff over ˜5000 km, extending a few 1000 km beyond the orbit of Amalthea, and a more gradual inner dropoff over 15,000-20,000 km. The inner edge is near the location of the synchronous orbit. The optical depth in the Amalthea ring is ˜5×10, up to 20% of which is comprised of macroscopic material. The optical depth in the Thebe ring is a factor of 3 smaller.

  9. Keck Adaptive Optics Imaging of Uranus and its Rings

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Roe, H.; Macintosh, B.; Gibbard, S.; Max, C.; Gavel, D.

    2000-10-01

    We observed Uranus with the recently commissioned AO/NIRSPEC system (Adaptive Optics system with the Near-Infrared echelle Spectrograph) on the 10-m W.M. Keck telescope, UT June 17 and 18, 2000. NIRSPEC allows one to take images and spectra simultaneously. Here we will discuss the images at wavelengths between 1 and 2.4 micron. Due to the location of the rings' pericenter, the rings were much brighter in the north than the south, which resulted in excellent ring images. Inside of the ɛ ring at least three more (individually slightly resolved) rings are visible: from the outside inwards these are: 1) combined δ ,γ ,η rings, 2) combined β ,α rings, and 3) combined 4,5,6 rings. On the planet itself we detected at least 8 different cloud features, five of which were in the northern hemisphere. Two features could be tracked over a 40-60 degree longitude range, and yield wind velocities of 175 +/- 35 m/s at a latitude of +30o, and of 120 +/- 40 m/s at +40o latitude. The highest latitude reached by HST NICMOS was +27o, where a velocity of 20 m/s was measured (Karkoschka, 1998). Has the wind speed changed? Or is there a very steep gradient in the profile? Our data suggest the wind profile to be similar to that derived for Neptune, though at reduced velocities. This research was supported in part by the STC Program of the National Science Foundation under Agreement No. AST-9876783, and in part under the auspices of the US Department of Energy at Lawrence Livermore National Laboratory, Univ. of Calif. under contract No. W-7405-Eng-48.

  10. The Operation and Architecture of the Keck Observatory Archive

    NASA Astrophysics Data System (ADS)

    Berriman, G. B.; Gelino, C. R.; Laity, A.; Kong, M.; Swain, M.; Holt, J.; Goodrich, R.; Mader, J.; Tran, H. D.

    2014-05-01

    The Infrared Processing and Analysis Center (IPAC) and the W. M. Keck Observatory (WMKO) are collaborating to build an archive for the twin 10-m Keck Telescopes, located near the summit of Mauna Kea. The Keck Observatory Archive (KOA) takes advantage of IPAC's long experience with managing and archiving large and complex data sets from active missions and serving them to the community; and of the Observatory's knowledge of the operation of its sophisticated instrumentation and the organization of the data products. By the end of 2013, KOA will contain data from all eight active observatory instruments, with an anticipated volume of 28 TB. The data include raw science and observations, quick look products, weather information, and, for some instruments, reduced and calibrated products. The goal of including data from all instruments is the cumulation of a rapid expansion of the archive's holdings, and already data from four new instruments have been added since October 2012. One more active instrument, the integral field spectrograph OSIRIS, is scheduled for ingestion in December 2013. After preparation for ingestion into the archive, the data are transmitted electronically from WMKO to IPAC for curation in the physical archive. This process includes validation of the science and content of the data and verification that data were not corrupted in transmission. The archived data include both newly-acquired observations and all previously acquired observations. The older data extends back to the date of instrument commissioning; for some instruments, such as HIRES, these data can extend as far back as 1994. KOA will continue to ingest all newly obtained observations, at an anticipated volume of 4 TB per year, and plans to ingest data from two decommissioned instruments. Access to these data is governed by a data use policy that guarantees Principal Investigators (PI) exclusive access to their data for at least 18 months, and allows for extensions as granted by

  11. VizieR Online Data Catalog: Keck/HIRES radial velocity obs. of HD32963 (Rowan+, 2016)

    NASA Astrophysics Data System (ADS)

    Rowan, D.; Meschiari, S.; Laughlin, G.; Vogt, S. S.; Butler, R. P.; Burt, J.; Wang, S.; Holden, B.; Hanson, R.; Arriagada, P.; Keiser, S.; Teske, J.; Diaz, M.

    2016-04-01

    The Lick-Carnegie Exoplanet Survey (LCES) is a search for exoplanets using the Keck I optical telescope of the W. M. Keck Observatory in Hawaii. We used the HIRES spectrometer telescope for all the radial velocity (RV) observations presented in this paper. Table 2 shows the complete set of our RV observations for HD 32963. Our data set comprises 109 measurements over approximately 16 years (5838 days); between 1998 January 24 and 2014 January 18. (1 data file).

  12. Development of a state machine sequencer for the Keck Interferometer: evolution, development, and lessons learned using a CASE tool approach

    NASA Astrophysics Data System (ADS)

    Reder, Leonard J.; Booth, Andrew; Hsieh, Jonathan; Summers, Kellee R.

    2004-09-01

    This paper presents a discussion of the evolution of a sequencer from a simple Experimental Physics and Industrial Control System (EPICS) based sequencer into a complex implementation designed utilizing UML (Unified Modeling Language) methodologies and a Computer Aided Software Engineering (CASE) tool approach. The main purpose of the Interferometer Sequencer (called the IF Sequencer) is to provide overall control of the Keck Interferometer to enable science operations to be carried out by a single operator (and/or observer). The interferometer links the two 10m telescopes of the W. M. Keck Observatory at Mauna Kea, Hawaii. The IF Sequencer is a high-level, multi-threaded, Harel finite state machine software program designed to orchestrate several lower-level hardware and software hard real-time subsystems that must perform their work in a specific and sequential order. The sequencing need not be done in hard real-time. Each state machine thread commands either a high-speed real-time multiple mode embedded controller via CORBA, or slower controllers via EPICS Channel Access interfaces. The overall operation of the system is simplified by the automation. The UML is discussed and our use of it to implement the sequencer is presented. The decision to use the Rhapsody product as our CASE tool is explained and reflected upon. Most importantly, a section on lessons learned is presented and the difficulty of integrating CASE tool automatically generated C++ code into a large control system consisting of multiple infrastructures is presented.

  13. Development of a State Machine Sequencer for the Keck Interferometer: Evolution, Development and Lessons Learned using a CASE Tool Approach

    NASA Technical Reports Server (NTRS)

    Rede, Leonard J.; Booth, Andrew; Hsieh, Jonathon; Summer, Kellee

    2004-01-01

    This paper presents a discussion of the evolution of a sequencer from a simple EPICS (Experimental Physics and Industrial Control System) based sequencer into a complex implementation designed utilizing UML (Unified Modeling Language) methodologies and a CASE (Computer Aided Software Engineering) tool approach. The main purpose of the sequencer (called the IF Sequencer) is to provide overall control of the Keck Interferometer to enable science operations be carried out by a single operator (and/or observer). The interferometer links the two 10m telescopes of the W. M. Keck Observatory at Mauna Kea, Hawaii. The IF Sequencer is a high-level, multi-threaded, Hare1 finite state machine, software program designed to orchestrate several lower-level hardware and software hard real time subsystems that must perform their work in a specific and sequential order. The sequencing need not be done in hard real-time. Each state machine thread commands either a high-speed real-time multiple mode embedded controller via CORB A, or slower controllers via EPICS Channel Access interfaces. The overall operation of the system is simplified by the automation. The UML is discussed and our use of it to implement the sequencer is presented. The decision to use the Rhapsody product as our CASE tool is explained and reflected upon. Most importantly, a section on lessons learned is presented and the difficulty of integrating CASE tool automatically generated C++ code into a large control system consisting of multiple infrastructures is presented.

  14. Data reduction pipelines for the Keck Observatory Archive

    NASA Astrophysics Data System (ADS)

    Tran, H. D.; Cohen, R.; Colson, A.; Mader, J. A.; Swain, M.; Laity, A. C.; Kong, M.; Gelino, C. R.; Berriman, G. B.

    2016-07-01

    The Keck Observatory Archive (KOA) currently serves 42 TB of data spanning over 20 years from all ten past and current facility instruments at Keck. Although most of the available data are in the raw form, for four instruments (HIRES, NIRC2, OSIRIS, LWS), quick-look, browse products generated by automated pipelines are also offered to facilitate assessment of the scientific content and quality of the data. KOA underwrote the update of the MAKEE package to support reduction of the CCD upgrade to HIRES, developed scripts for reduction of NIRC2 data and automated the existing OSIRIS and LWS data reduction packages. We describe in some detail the recently completed automated pipeline for NIRSPEC, which will be used to create browse products in KOA and made available for quicklook of the data by the observers at the telescope. We review the currently available data reduction tools for Keck data, and present our plans and anticipated priorities for the development of automated pipelines and release of reduced data products for the rest of the current and future instruments. We also anticipate that Keck's newest instrument, NIRES, which will be delivered with a fully automated pipeline, will be the first to have both raw and level-1 data ingested at commissioning.

  15. bicep2/KECK ARRAY. IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS

    SciTech Connect

    Ade, P. A. R.; Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R.; Hui, H.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bradford, K. J.; Buder, I.; Bullock, E.; Dowell, C. D.; Duband, L.; Fliescher, S.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Collaboration: bicep2 and Keck Array Collaborations; and others

    2015-06-20

    bicep2 and the Keck Array are polarization-sensitive microwave telescopes that observe the cosmic microwave background (CMB) from the South Pole at degree angular scales in search of a signature of inflation imprinted as B-mode polarization in the CMB. bicep2 was deployed in late 2009, observed for three years until the end of 2012 at 150 GHz with 512 antenna-coupled transition edge sensor bolometers, and has reported a detection of B-mode polarization on degree angular scales. The Keck Array was first deployed in late 2010 and will observe through 2016 with five receivers at several frequencies (95, 150, and 220 GHz). bicep2 and the Keck Array share a common optical design and employ the field-proven bicep1 strategy of using small-aperture, cold, on-axis refractive optics, providing excellent control of systematics while maintaining a large field of view. This design allows for full characterization of far-field optical performance using microwave sources on the ground. Here we describe the optical design of both instruments and report a full characterization of the optical performance and beams of bicep2 and the Keck Array at 150 GHz.

  16. The Keck Cosmic Web Imager: a capable new integral field spectrograph for the W. M. Keck Observatory

    NASA Astrophysics Data System (ADS)

    Morrissey, Patrick; Matuszewski, Mateusz; Martin, Chris; Moore, Anna; Adkins, Sean; Epps, Harland; Bartos, Randy; Cabak, Jerry; Cowley, Dave; Davis, Jack; Delacroix, Alex; Fucik, Jason; Hilliard, David; James, Ean; Kaye, Steve; Lingner, Nicole; Neill, James D.; Pistor, Christoph; Phillips, Drew; Rockosi, Connie; Weber, Bob

    2012-09-01

    The Keck Cosmic Web Imager (KCWI) is a new facility instrument being developed for the W. M. Keck Observatory and funded for construction by the Telescope System Instrumentation Program (TSIP) of the National Science Foundation (NSF). KCWI is a bench-mounted spectrograph for the Keck II right Nasmyth focal station, providing integral field spectroscopy over a seeing-limited field up to 20"x33" in extent. Selectable Volume Phase Holographic (VPH) gratings provide high efficiency and spectral resolution in the range of 1000 to 20000. The dual-beam design of KCWI passed a Preliminary Design Review in summer 2011. The detailed design of the KCWI blue channel (350 to 700 nm) is now nearly complete, with the red channel (530 to 1050 nm) planned for a phased implementation contingent upon additional funding. KCWI builds on the experience of the Caltech team in implementing the Cosmic Web Imager (CWI), in operation since 2009 at Palomar Observatory. KCWI adds considerable flexibility to the CWI design, and will take full advantage of the excellent seeing and dark sky above Mauna Kea with a selectable nod-and-shuffle observing mode. In this paper, models of the expected KCWI sensitivity and background subtraction capability are presented, along with a detailed description of the instrument design. The KCWI team is lead by Caltech (project management, design and implementation) in partnership with the University of California at Santa Cruz (camera optical and mechanical design) and the W. M. Keck Observatory (program oversight and observatory interfaces).

  17. Adaptive Optics Performance at Lick and Keck Observatory

    NASA Astrophysics Data System (ADS)

    Max, C. E.; Olivier, S. S.; Avicola, K.; Bissinger, H. D.; Brase, J. M.; Friedman, H. W.; Gavel, D. T.; Salmon, J. T.; Waltjen, K. E.

    1993-12-01

    The performance of an adaptive optics system developed for the 40 inch Nickel and 120 inch Shane telescopes at Lick Observatory is discussed. The system is based on a 69 actuator continuous-surface deformable mirror and a Hartmann wavefront sensor equipped with a commercial intensified CCD fast-framing camera. Results from tests of this adaptive optics system using natural reference stars on the 40 inch Nickel telescope are presented. These results are compared to the performance predicted by simulations and analyses. Predictions for the system performance on the 120 inch Shane telescope and on the 10 meter Keck telescope using both natural and laser reference stars are also presented. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

  18. Is Draco II one of the faintest dwarf galaxies? First study from Keck/DEIMOS spectroscopy

    NASA Astrophysics Data System (ADS)

    Martin, Nicolas F.; Geha, Marla; Ibata, Rodrigo A.; Collins, Michelle L. M.; Laevens, Benjamin P. M.; Bell, Eric F.; Rix, Hans-Walter; Ferguson, Annette M. N.; Chambers, Kenneth C.; Wainscoat, Richard J.; Waters, Christopher

    2016-05-01

    We present the first spectroscopic analysis of the faint and compact stellar system Draco II (Dra II, MV = -2.9 ± 0.8, r_h=19^{+8}_{-6} pc), recently discovered in the Panoramic Survey Telescope and Rapid Response System 1 3π survey. The observations, conducted with DEIMOS on the Keck II telescope, establish some of its basic characteristics: the velocity data reveal a narrow peak with nine member stars at a systemic heliocentric velocity < v_rrangle =-347.6^{+1.7}_{-1.8} km s^{-1}, thereby confirming Dra II is a satellite of the Milky Way; we infer a velocity dispersion with σvr = 2.9 ± 2.1 km s-1 (<8.4 km s-1 at the 95 per cent confidence level), which implies log _{10}(M_{1/2})=5.5^{+0.4}_{-0.6} and log _{10}(({M/L})_{1/2})=2.7^{+0.5}_{-0.8}, in Solar units; furthermore, very weak calcium triplet lines in the spectra of the high signal-to-noise member stars imply [Fe/H] < -2.1, whilst variations in the line strengths of two stars with similar colours and magnitudes suggest a metallicity spread in Dra II. These new data cannot clearly discriminate whether Draco II is a star cluster or amongst the faintest, most compact, and closest dwarf galaxies. However, the sum of the three - individually inconclusive - pieces of evidence presented here seems to favour the dwarf galaxy interpretation.

  19. Slitmasks for instruments at Keck Observatory

    NASA Astrophysics Data System (ADS)

    Allen, S. L.; Clarke, D. A.; Phillips, A. C.; Wirth, G. D.

    2004-05-01

    DEIMOS and LRIS are multi-slit spectrographs used with the 10-meter telescopes at W.M. Keck Observatory on Mauna Kea. Their focal planes admit light from celestial objects through slitlets cut into interchangeable aluminum sheets. Each observing night may use a dozen custom-cut slitmasks. Each mask may have dozens, or even hundreds, of slitlets. The process of observing through a slitmask starts with an astronomer choosing targets. Ideally it ends with FITS files which contain images of spectra from each slitlet and tables which document the slitlets and the objects viewed through them. We describe the system which handles slitmasks for Keck from the point where the astronomer has completed the mask design to the point where archival FITS files have been constructed. This system was created for DEIMOS and later retrofitted to LRIS. DEIMOS slitmask design files (MDFs) contain FITS tables that document objects and slitlets on the sky and on the metal. The observer submits MDFs via a web interface which authenticates the user, validates the input, and inserts the mask design into a relational database (RDB). Consistency checks later verify each slitlet and alert the observer of any problems via e-mail. Astronomers and engineers can check the status of masks via additional web interfaces which query the RDB. At the milling facility a graphical user interface (GUI) queries the RDB to display a prioritized queue of masks to be manufactured. A machinist uses the GUI to produce code for a numerically-controlled mill. Manufactured masks receive a barcode to identify them uniquely for use during observation. The DEIMOS observing software queries the database and attaches to each image a set of FITS tables describing the slitmask. This allows DEIMOS software to align the mask on the sky automatically to sub-arcsecond precision.

  20. HUBBLE AND KECK DISCOVER GALAXY BUILDING BLOCK

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This NASA Hubble Space Telescope image shows a very small, faint galaxy 'building block' newly discovered by a unique collaboration between ground- and space-based telescopes. Hubble and the 10-meter Keck Telescopes in Hawaii joined forces, using a galaxy cluster which acts as gravitational lens to detect what scientists believe is one of the smallest very distant objects ever found. The galaxy cluster Abell 2218 was used by a team of European and American astronomers led by Richard Ellis (Caltech) in their systematic search for intrinsically faint distant star-forming systems. Without help from Abell 2218's exceptional magnifying power to make objects appear about 30 times brighter, the galaxy building block would have been undetectable. In the image to the right, the object is seen distorted into two nearly identical, very red 'images' by the gravitational lens. The image pair represents the magnified result of a single background object gravitationally lensed by Abell 2218 and viewed at a distance of 13.4 billion light-years. The intriguing object contains only one million stars, far fewer than a mature galaxy, and scientists believe it is very young. Such young star-forming systems of low mass at early cosmic times are likely to be the objects from which present-day galaxies have formed. In the image to the left, the full overview of the galaxy cluster Abell 2218 is seen. This image was taken by Hubble in 1999 at the completion of Hubble Servicing Mission 3A. Credit: NASA, ESA, Richard Ellis (Caltech) and Jean-Paul Kneib (Observatoire Midi-Pyrenees, France) Acknowledgment: NASA, A. Fruchter and the ERO Team (STScI and ST-ECF)

  1. Near infra-red astronomy with adaptive optics and laser guide stars at the Keck Observatory

    SciTech Connect

    Max, C.E.; Gavel, D.T.; Olivier, S.S.

    1995-08-03

    A laser guide star adaptive optics system is being built for the W. M. Keck Observatory`s 10-meter Keck II telescope. Two new near infra-red instruments will be used with this system: a high-resolution camera (NIRC 2) and an echelle spectrometer (NIRSPEC). The authors describe the expected capabilities of these instruments for high-resolution astronomy, using adaptive optics with either a natural star or a sodium-layer laser guide star as a reference. They compare the expected performance of these planned Keck adaptive optics instruments with that predicted for the NICMOS near infra-red camera, which is scheduled to be installed on the Hubble Space Telescope in 1997.

  2. Speckle nulling wavefront control for Palomar and Keck

    NASA Astrophysics Data System (ADS)

    Bottom, Michael; Femenia, Bruno; Huby, Elsa; Mawet, Dimitri; Dekany, Richard; Milburn, Jennifer; Serabyn, Eugene

    2016-07-01

    We present a speckle nulling code currently being used for high contrast imaging at the Palomar and Keck telescopes. The code can operate in open and closed loop and is self-calibrating, requiring no system model and minimal hand-coded parameters. Written in a modular fashion, it is straightforward to port to different instruments. It has been used with systems operating in the optical through thermal infrared, and can deliver nearly an order of magnitude improvement in raw contrast. We will be releasing this code to the public in the near future.

  3. Initial Performance of the Keck AO Wavefront Controller System

    SciTech Connect

    Johansson, E M; Acton, D S; An, J R; Avicola, K; Beeman, B V; Brase, J M; Carrano, C J; Gathright, J; Gavel, D T; Hurd, R L; Lai, O; Lupton, W; Macintosh, B A; Max, C E; Olivier, S S; Shelton, J C; Stomski, P J; Tsubota, K; Waltjen, K E; Watson, J A; Wizinowich, P L

    2001-03-01

    The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control loop to remove tilt from the incoming wavefront, and a deformable mirror control loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from the experimental data and compared to theory. The residual wavefront errors due to control loop bandwidth are also calculated from the data, and possible improvements to the controller performance are discussed.

  4. Initial performance of the Keck AO wavefront controller system

    NASA Astrophysics Data System (ADS)

    Johansson, Erik M.; Acton, D. Scott; An, Jong R.; Avicola, Kenneth; Beeman, Bart V.; Brase, James M.; Carrano, Carmen J.; Gathright, John; Gavel, Donald T.; Hurd, Randall L.; Lai, Olivier; Lupton, William; Macintosh, Bruce A.; Max, Claire E.; Olivier, Scot S.; Shelton, J. Christopher; Stomski, Paul J.; Tsubota, Kevin; Waltjen, Kenneth E.; Watson, James A.; Wizinowich, Peter L.

    2000-07-01

    The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control loop to remove tilt from the incoming wavefront, and a deformable mirror control loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from the experimental data and compared to theory. The residual wavefront errors due to control loop bandwidth are also calculated from the data, and possible improvements to the controller performance are discussed.

  5. Optical Positions of ICRF Sources from CTIO 1.0M Data

    DTIC Science & Technology

    2015-01-01

    ABSTRACT As part of the USNO radio-optical reference frame link project, data were taken with the CTIO 1.0 m telescope in 2009. First position...ABSTRACT As part of the USNO radio-optical reference frame link project, data were taken with the CTIO 1.0 m telescope in 2009. First position...Yale 1.0 meter telescope and Y4K camera which were used for this study. TABLE 1. INSTRUMENT PROPERTIES aperture 1000 mm focal ratio f/10 Cass. filters

  6. An overview of the Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Serabyn, Eugen

    2003-01-01

    The first high dynamic range interferometry mode planned to come on line at the Keck Observatory is mid-infrared nulling interferometry. In this paper, an overview is given of the goals and experimental configuration of the Keck Interferometer Nuller (KIN).

  7. THE DEEP3 GALAXY REDSHIFT SURVEY: KECK/DEIMOS SPECTROSCOPY IN THE GOODS-N FIELD

    SciTech Connect

    Cooper, Michael C.; Aird, James A.; Coil, Alison L. E-mail: acoil@ucsd.edu

    2011-03-15

    We present the results of spectroscopic observations in the GOODS-N field completed using DEIMOS on the Keck II telescope as part of the DEEP3 Galaxy Redshift Survey. Observations of 370 unique targets down to a limiting magnitude of R {sub AB} = 24.4 yielded 156 secure redshifts. In addition to redshift information, we provide sky-subtracted one- and two-dimensional spectra of each target. Observations were conducted following the procedures of the Team Keck Redshift Survey (TKRS), thereby producing spectra that augment the TKRS sample while maintaining the uniformity of its spectral database.

  8. Point spread function determination for Keck adaptive optics

    NASA Astrophysics Data System (ADS)

    Ragland, S.; Jolissaint, L.; Wizinowich, P.; van Dam, M. A.; Mugnier, L.; Bouxin, A.; Chock, J.; Kwok, S.; Mader, J.; Witzel, G.; Do, Tuan; Fitzgerald, M.; Ghez, A.; Lu, J.; Martinez, G.; Morris, M. R.; Sitarski, B.

    2016-07-01

    One of the primary scientific limitations of adaptive optics (AO) has been the incomplete knowledge of the point spread function (PSF), which has made it difficult to use AO for accurate photometry and astrometry in both crowded and sparse fields, for extracting intrinsic morphologies and spatially resolved kinematics, and for detecting faint sources in the presence of brighter sources. To address this limitation, we initiated a program to determine and demonstrate PSF reconstruction for science observations obtained with Keck AO. This paper aims to give a broad view of the progress achieved in implementing a PSF reconstruction capability for Keck AO science observations. This paper describes the implementation of the algorithms, and the design and development of the prototype operational tools for automated PSF reconstruction. On-sky performance is discussed by comparing the reconstructed PSFs to the measured PSF's on the NIRC2 science camera. The importance of knowing the control loop performance, accurate mapping of the telescope pupil to the deformable mirror and the science instrument pupil, and the telescope segment piston error are highlighted. We close by discussing lessons learned and near-term future plans.

  9. Telescope Adaptive Optics Code

    SciTech Connect

    Phillion, D.

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The default parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST

  10. Photon-Weighted Midpoint Exposure Meter for Keck/HIRES Extrasolar Planet Research

    NASA Technical Reports Server (NTRS)

    1999-01-01

    NASA Grant was received for research involving the construction of a photon-weighting midpoint exposure meter for the Keck HIRES spectrometer, and for support of our NASA/Keck-based planet research with this instrumentation. The research funds were also to be used to make our iodine cell calibration system and exposure meter available to the NASA Keck observing community. Progress this past year, the second of the 3-year granting period, involved work in 4 areas: 1) Further construction of the midpoint exposure meter. 2) Assisting observers with use of the Iodine system. 3) Acquisition of precision radial velocity data on our program star sample with continued monitoring to proceed in subsequent years as available telescope time permits. 4) Reduction and analysis of incoming precision radial velocity data to reject problematic and uninteresting program stars, and to identify promising planet candidates.

  11. bicep2/ KECK ARRAY . IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS

    SciTech Connect

    Ade, P. A. R.; Aikin, R. W.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bradford, K. J.; Brevik, J. A.; Buder, I.; Bullock, E.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hui, H.; Irwin, K. D.; Kang, J. H.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O’Brient, R.; IV, R. W. Ogburn; Orlando, A.; Pryke, C.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wong, C. L.; Yoon, K. W.

    2015-06-18

    bicep2/KECK ARRAY. IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS P. A. R. Ade1, R. W. Aikin2, D. Barkats3, S. J. Benton4, C. A. Bischoff5, J. J. Bock2,6, K. J. Bradford5, J. A. Brevik2, I. Buder5, E. Bullock7Show full author list Published 2015 June 18 • © 2015. The American Astronomical Society. All rights reserved. The Astrophysical Journal, Volume 806, Number 2 Article PDF Figures Tables References Citations 273 Total downloads Cited by 6 articles Turn on MathJax Share this article Get permission to re-use this article Article information Abstract bicep2 and the Keck Array are polarization-sensitive microwave telescopes that observe the cosmic microwave background (CMB) from the South Pole at degree angular scales in search of a signature of inflation imprinted as B-mode polarization in the CMB. bicep2 was deployed in late 2009, observed for three years until the end of 2012 at 150 GHz with 512 antenna-coupled transition edge sensor bolometers, and has reported a detection of B-mode polarization on degree angular scales. The Keck Array was first deployed in late 2010 and will observe through 2016 with five receivers at several frequencies (95, 150, and 220 GHz). bicep2 and the Keck Array share a common optical design and employ the field-proven bicep1 strategy of using small-aperture, cold, on-axis refractive optics, providing excellent control of systematics while maintaining a large field of view. This design allows for full characterization of far-field optical performance using microwave sources on the ground. Here we describe the optical design of both instruments and report a full characterization of the optical performance and beams of bicep2 and the Keck Array at 150 GHz.

  12. Smart co-phasing system for segmented mirror telescopes

    NASA Astrophysics Data System (ADS)

    Simar, Juan F.; Stockman, Yvan; Surdej, Jean

    2016-07-01

    Space observations of fainter and more distant astronomical objects constantly require telescope primary mirrors with a larger size. The diameter of monolithic primary mirrors is limited to 10 m because of manufacturing and logistics limitations. For space telescopes, monolithic primary mirrors are limited to less than 5 m due to fairing capacity. Segmented primary mirrors thus constitute an alternative solution to deal with the steadily increase of the primary mirror size. The optical path difference between the individual segments must be close to zero (few nm) in order to be diffraction limited over the full telescope aperture. In this paper a new system that may co-phase 7 segments at once with the light of a star and without artificial one is proposed. First the measuring methods and feedback system is explained, then the breadboard setup is presented and the results are analyzed and discussed, finally a comparison with Keck telescope is performed. This system can be adapted in order to be used in the co-phasing system of future segmented mirrors, its dynamic range starts from several hundred of microns till some tenths of nanometers

  13. Dynamics and Stellar Content of the Giant Southern Stream in M31. I. Keck Spectroscopy of Red Giant Stars

    NASA Astrophysics Data System (ADS)

    Guhathakurta, Puragra; Rich, R. Michael; Reitzel, David B.; Cooper, Michael C.; Gilbert, Karoline M.; Majewski, Steven R.; Ostheimer, James C.; Geha, Marla C.; Johnston, Kathryn V.; Patterson, Richard J.

    2006-05-01

    This paper presents the first results from a large spectroscopic survey of red giant branch (RGB) stars in M31 using DEIMOS on the Keck 10 m telescope. A photometric prescreening method, based on the intermediate-width DDO51 band centered on the Mg b/MgH absorption feature, was used to select spectroscopic targets. RGB candidates were targeted in a small section of M31's giant southern tidal stream at a projected distance of 31 kpc from the galaxy's center. We isolate a clean sample of 68 RGB stars by removing contaminants (foreground Milky Way dwarf stars and background galaxies) using a combination of spectroscopic, imaging, and photometric methods: radial velocity and the surface gravity-sensitive Na I doublet are particularly useful in this regard. About 65% of the M31 stars are found to be members of the giant southern stream, while the rest appear to be members of the general spheroid population. The mean (heliocentric) radial velocity of the stream in our field is -458 km s-1, blueshifted by -158 km s-1 relative to M31's systemic velocity, in good agreement with recent velocity measurements at other points along the stream. The intrinsic velocity dispersion of the stream is found to be 15+8-15 km s-1 (90% confidence limit). A companion paper by Font and coworkers discusses possible orbits, implications of the coldness of the stream, and properties of the progenitor satellite galaxy. The kinematics, and possibly the metallicity distribution, of the general spheroid (i.e., nonstream) population in this region of M31 indicate that it is significantly different from samples drawn from other parts of the M31 spheroid; this is probably an indication of substructure in the bulge and halo. The stream appears to have a higher mean metallicity than the general spheroid, <[Fe/H]>~-0.54 versus -0.74, and a smaller metallicity spread. The relatively high metallicity of the stream implies that its progenitor must have been a luminous dwarf galaxy. The Ca II triplet line

  14. Performance of keck adaptive optics with sodium laser guide star

    SciTech Connect

    Gavel, D.T.; Olivier, S.; Brase, J.

    1996-03-08

    The Keck telescope adaptive optics system is designed to optimize performance in he 1 to 3 micron region of observation wavelengths (J, H, and K astronomical bands). The system uses a 249 degree of freedom deformable mirror, so that the interactuator spacing is 56 cm as mapped onto the 10 meter aperture. 56 cm is roughly equal to r0 at 1.4 microns, which implies the wavefront fitting error is 0.52 ({lambda}/2{pi})({ital d}/{ital r}{sub 0}){sup 5/6} = 118 nm rms. This is sufficient to produce a system Strehl of 0.74 at 1.4 microns if all other sources of error are negligible, which would be the case with a bright natural guidestar and very high control bandwidth. Other errors associated with the adaptive optics will however contribute to Strehl degradation, namely, servo bandwidth error due to inability to reject all temporal frequencies of the aberrated wavefront, wavefront measurement error due to finite signal-to-noise ratio in the wavefront sensor, and, in the case of a laser guidestar, the so-called cone effect where rays from the guidestar beacon fail to sample some of the upper atmosphere turbulence. Cone effect is mitigated considerably by the use of the very high altitude sodium laser guidestar (90 km altitude), as opposed to Rayleigh beacons at 20 km. However, considering the Keck telescope`s large aperture, this is still the dominating wavefront error contributor in the current adaptive optics system design.

  15. Keck adaptive optics images of Jupiter's north polar cap and Northern Red Oval

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Wong, Michael H.; de Kleer, Katherine; Hammel, Heidi B.; Ádámkovics, Máté; Conrad, Al

    2011-06-01

    We present observations at near-infrared wavelengths (1-5 μm) of Jupiter's north polar region and Northern Red Oval (NN-LRS-1). The observations were taken with the near-infrared camera NIRC2 coupled to the adaptive optics system on the 10-m W.M. Keck Telescope on UT 21 August 2010. At 5-μm Jupiter's disk reveals considerable structure, including small bright rings which appear to surround all small vortices. It is striking, though, that no such ring is seen around the Northern Red Oval. In de Pater et al. [2010a. Icarus 210, 742-762], we showed that such rings also exist around all small vortices in Jupiter's southern hemisphere, and are absent around the Great Red Spot and Red Oval BA. We show here that the vertical structure and extent of the Northern Red Oval is very similar to that of Jupiter's Red Oval BA. These new observations of the Northern Red Oval, therefore, support the idea of a dichotomy between small and large anticyclones, in which ovals larger than about two Rossby deformation radii do not have 5-μm bright rings. In de Pater et al. [2010a. Icarus 210, 742-762], we explained this difference in terms of the secondary circulations within the vortices. We further compare the brightness distribution of our new 5-μm images with previously published radio observations of Jupiter, highlighting the depletion of NH 3 gas over areas that are bright at 5 μm.

  16. J-Band Infrared Spectroscopy of a Sample of Brown Dwarfs Using NIRSPEC on Keck II.

    PubMed

    McLean; Wilcox; Becklin; Figer; Gilbert; Graham; Larkin; Levenson; Teplitz; Kirkpatrick

    2000-04-10

    Near-infrared spectroscopic observations of a sample of very cool, low-mass objects are presented with higher spectral resolution than in any previous studies. Six of the objects are L dwarfs, ranging in spectral class from L2 to L8/9, and the seventh is a methane or T dwarf. These new observations were obtained during commissioning of the near-infrared spectrometer (NIRSPEC), the first high-resolution near-infrared cryogenic spectrograph for the Keck II 10 m telescope on Mauna Kea, Hawaii. Spectra with a resolving power of R approximately 2500 from 1.135 to 1.360 µm (approximately J band) are presented for each source. At this resolution, a rich spectral structure is revealed, much of which is due to blending of unresolved molecular transitions. Strong lines due to neutral potassium (K i) and bands due to iron hydride (FeH) and steam (H2O) change significantly throughout the L sequence. Iron hydride disappears between L5 and L8, the steam bands deepen, and the K i lines gradually become weaker but wider because of pressure broadening. An unidentified feature occurs at 1.22 µm that has a temperature dependence like FeH but has no counterpart in the available FeH opacity data. Because these objects are 3-6 mag brighter in the near-infrared compared with the I band, spectral classification is efficient. One of the objects studied (2MASSW J1523+3014) is the coolest L dwarf discovered so far by the 2 Micron All-Sky Survey (2MASS), but its spectrum is still significantly different from the methane-dominated objects such as Gl 229B or SDSS 1624+0029.

  17. Asteroid (16) Psyche: Triaxial Ellipsoid Dimensions and Rotational Pole from Keck II NIRC2 AO Images and Keck I OSIRIS Images

    NASA Astrophysics Data System (ADS)

    Drummond, Jack D.; Conrad, Al; Reddy, Vishnu; de Kleer, Katherine R.; Adamkovics, Mate; de Pater, Imke; Merline, William J.; Tamblyn, Peter

    2016-10-01

    Adaptive optics (AO) images of asteroid (16) Psyche obtained at 4 epochs with the NIRC2 camera at the 10m W. M. Keck Observatory (Keck II) on UT 2015 December 25 lead to triaxial ellipsoid diameters of 279±4 x 230±2 x 195±14 km, and a rotational pole at RA=29° and Dec=-2°. Adding 6 more epochs obtained nearly simultaneously with the OSIRIS system at Keck I, as well as two more epochs from Keck II in 2009, yields diameters of 273±2 x 232±2 x 165±3 km, and a pole at RA=37° and Dec=+1°. (Errors are formal fit parameter uncertainties; an additional 4% uncertainty is possible from systematic biases.) The differing perspectives between 2015 (sub-Earth latitude Θ=-50°) and 2009 (Θ=-6°) improves primarily the c dimension and the location of the rotational pole, but illustrates how well images from even a single night can determine the size, shape, and pole of an asteroid. The 2015 observations were obtained as part of a campaign to study Psyche with many techniques over a few months, including radar from Arecibo and images from Magellan.These handful of images show the same rugged outline as the radius vector model available on the DAMIT website, constructed from many lightcurves and scaled by previous Keck AO images. In fact Psyche has rotated some 125,350 times between the first lightcurve in 1955 and our 2015 AO images, exactly 60 years apart to the day. Since the asteroid has such a high obliquity, these lightcurves have scanned well into both northern and southern hemispheres. The difference between the pole derived from our images and the radius vector model pole is only 7°, and the mean diameters of Psyche are 219 and 211 km, respectively.

  18. Metallicity and Kinematics of M31's Outer Stellar Halo from a Keck Spectroscopic Survey

    NASA Astrophysics Data System (ADS)

    Reitzel, David B.; Guhathakurta, Puragra

    2002-07-01

    We present first results from a spectroscopic survey designed to examine the metallicity and kinematics of individual red giant branch stars in the outer halo of the Andromeda spiral galaxy (M31). This study is based on multislit spectroscopy with the Keck II 10 m telescope and Low Resolution Imaging Spectrograph of the Ca II near-infrared triplet in 99 M31 halo candidates in a field at R=19 kpc on the southeast minor axis with brightnesses from 20~2 dex range over which the abundance measurement methods are calibrated. The mean/median metallicity of the M31 halo is about <[Fe/H]>=-1.9 to -1.1 dex (depending on the details of metallicity calibration and sample selection) and possibly higher: the high-metallicity end of the distribution is poorly constrained by our data since the selection function for the secure M31 sample excludes over 80% of the giants in solar/supersolar metallicity range. Possible reasons are

  19. Nulling Measurements with the Keck Interferometer

    SciTech Connect

    Serabyn, Eugene

    2009-08-05

    The Keck Interferometer provides a mid-infrared nulling capability that is designed to detect faint mid-infrared emission from the immediate vicinity of bright stars. The Keck Interferometer Nuller (KIN) has now been used to carry out initial shared-risk science observations, followed by three nulling key-science projects performed in the 2008 observing semesters. This paper describes the novel measurement technique employed by the KIN, and lists some of the initial observations obtained with it. These data sets are now in the process of being analyzed, and results should begin emerging in the near future.

  20. Nulling Measurements with the Keck Interferometer

    NASA Astrophysics Data System (ADS)

    Serabyn, Eugene

    2009-08-01

    The Keck Interferometer provides a mid-infrared nulling capability that is designed to detect faint mid-infrared emission from the immediate vicinity of bright stars. The Keck Interferometer Nuller (KIN) has now been used to carry out initial shared-risk science observations, followed by three nulling key-science projects performed in the 2008 observing semesters. This paper describes the novel measurement technique employed by the KIN, and lists some of the initial observations obtained with it. These data sets are now in the process of being analyzed, and results should begin emerging in the near future.

  1. Differential Phase Mode with the Keck Interferometer

    NASA Technical Reports Server (NTRS)

    Akeson, Rachel; Swain, Mark

    2000-01-01

    We describe the differential phase mode of the Keck Interferometer. The scientific goal of this mode is the direct detection and spectroscopic characterization of hot, Jupiter mass planets. We describe the differential phase effect, the basic observational mode, and the expected differential phase signatures for the extrasolar planets discovered through radial velocity searches.

  2. Visibility science operations with the Keck Interferometer

    NASA Technical Reports Server (NTRS)

    Wizinowich, P.; Akeson, R.; Colavita, M.; Gathright, J.; Appleby, E.; Bell, J.; Booth, A.; Dahl, W.; Hrynevych, M; Lynn, I.; Millan-Gabet, R.; Neyman, C.; Rudeen, A.; Saloga, T.; Summers, K.; Tsubota, K.

    2004-01-01

    The visibility science mode of the Keck Interferometer fully transitioned into operations with the successful completion of its operational readiness review in April, 2004. The goal of this paper is to describe this science mode and the operations structure that supports it.

  3. Keck Interferometer autoaligner : algorithms and techniques

    NASA Technical Reports Server (NTRS)

    Hrynevych, Michael A.; Tsubota, Kevin; Smythe, Robert; Dahla, Wayne; Bella, Jim; Colavita, M. Mark; Gathright, John; Meggars, Forest; Neyman, Christoper; Rudeen, Andy; van Belle, Gerard; Wizinowich, Peter

    2004-01-01

    The Keck Interferometer includes an autoalignment system consisting of pop-up targets located at strategic locations along the beam trains of each arm of the instrument along with a sensor and control system. We briefly describe the hardware of the system and then proceed to a description of the two operational modes of the system.

  4. Asteroid Detection with the Space Surveillance Telescope

    NASA Astrophysics Data System (ADS)

    Woods, D.; Shah, R.; Johnson, J.; Pearce, E.; Lambour, R.; Faccenda, W.

    2013-09-01

    The Space Surveillance Telescope (SST) is a 3.5 m wide field-of-view system developed for DARPA by MIT Lincoln Laboratory to advance the nation's capabilities in space situational awareness. In addition to the national interest in identifying and cataloging man-made space objects, there is a growing concern for near-Earth asteroid identification and tracking. MIT is developing a program to detect near-Earth asteroids, as an extension of the Lincoln Near-Earth Asteroid Research (LINEAR) survey, to identify potentially hazardous near-Earth objects, and to extend the catalog of known asteroids to smaller sizes (< 140 m). MIT believes SST's capability to detect asteroids on size scales as small as 5-10 m is well suited to provide NASA with a sample of small asteroids of interest for its proposed mission to send astronauts to near-Earth asteroids as a stepping-stone to further manned exploration of the Solar System. The Keck Institute for Space Studies (Brophy et al. 2012), studied the feasibility of asteroid capture into lunar orbit as a destination for additional investigation. A major requirement of such an effort is the development of a sample of suitable asteroids, a job that SST is uniquely able to achieve by means of its capacity for search rate and sensitivity. The SST also brings the capability of high speed photometry at rates of 100 Hz to 1 kHz; we present initial observations of asteroids using the photometers.

  5. The Atmosphere of Uranus as Imaged with Keck Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Hammel, H. B.; de Pater, I.; Gibbard, S. G.; Lockwood, G. W.; Rages, K.

    2004-12-01

    Adaptive optics imaging of Uranus was obtained with NIRC2 on the Keck II 10-meter telescope in October 2003 and July 2004 through J, H, and K' filters. Dozens of discrete features were detected in the atmosphere of Uranus. We report the first measurements of winds northward of +43 deg, the first direct measurement of equatorial winds, and the highest wind velocity seen yet on Uranus. At northern mid-latitudes, the winds may have accelerated when compared to earlier HST and Keck observations; southern wind speeds have not changed since Voyager measurements in 1986. The equator of Uranus exhibits a subtle wave structure, with diffuse patches roughly every 30 degs in longitude. There is no sign of a northern "polar collar" as is seen in the south, but a number of discrete features seen at the "expected" latitudes may signal its early stages of development. The largest cloud features on Uranus show complex structure extending over tens of degrees. On 4 July 2004, we detected a southern hemispheric cloud feature on Uranus at K', the first detection of a southern feature at or longward of 2 microns. H images showed an extended structure whose condensed core was co-located with the K'-bright feature. The core exhibited marked brightness variation, fading within just a few days. The initial brightness at K' indicates that the core's scattering particles reached altitudes above the 1-bar level, with the extended H feature residing below 1.1 bars. The core's rapid disappearance at K' indicates dynamical processes in the local vertical aerosol structure. HBH acknowledges support from NASA grants NAG5-11961 and NAG5-10451. IdP acknowledges support from NSF and the Technology Center for Adaptive Optics, managed by UCSC under cooperative agreement No. AST-9876783. SGG's work was performed under the auspices of the U.S. DoE National Nuclear Security Administration by the UC, LLNL under contract No. W-7405-Eng-48.

  6. An overview of the Keck Interferometer Nuller

    NASA Astrophysics Data System (ADS)

    Serabyn, Eugen

    2003-10-01

    The first high dynamic range interferometry mode planned to come on line at the Keck Observatory is mid-infrared nulling interferometry. In this paper, an overview is given of the goals and experimental configuration of the Keck Interferometer Nuller (KIN). After an introduction to the science enabled by mid-infrared nulling interferometry on the Keck Interferometer's baseline, a system level overview of the experiment is provided, which includes a discussion of the optical path-length matching and stabilization approaches. This is followed by brief tours of both the nulling beam-combiner breadboard and the mid-infrared camera to be used in the experiment. The paper concludes with a discussion of the performance levels attained to date with the mid-infrared nullers built at the Jet Propulsion Laboratory. These symmetric nullers, all based on the modified Mach-Zehnder beamcombiner configuration, have now experimentally verified the predicted dual-polarization nulling capability of a reversed beamsplitter pair arrangement. To date, the JPL nulling beamcombiners have nulled broadband thermal mid-infrared radiation to the 10-4 level, and monochromatic (10.6 μm CO2 laser) radiation to the 10-6 level.

  7. A multi-wavelength study of the 2009 impact on Jupiter: Comparison of high resolution images from Gemini, Keck and HST

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Fletcher, Leigh N.; Pérez-Hoyos, Santiago; Hammel, Heidi B.; Orton, Glenn S.; Wong, Michael H.; Luszcz-Cook, Statia; Sánchez-Lavega, Agustin; Boslough, Mark

    2010-12-01

    Within several days of A. Wesley's announcement that Jupiter was hit by an object on UT 19 July 2009, we observed the impact site with (1) the Hubble Space Telescope (HST) at UV through visible (225-924 nm) wavelengths, (2) the 10-m W.M. Keck II telescope in the near-infrared (1-5 μm), and (3) the 8-m Gemini-North telescope in the mid-infrared (7.7-18 μm). All observations reported here were obtained between 22 and 25 July 2009. Observations at visible and near-infrared wavelengths show that large (˜0.75-μm radius) dark (imaginary index of refraction mi ˜ 0.01-0.1) particulates were deposited at atmospheric pressures between 10 and 200-300 mbar; analysis of HST-UV data reveals that in addition smaller-sized (˜0.1 μm radius) material must have been deposited at the highest altitudes (˜10 mbar). Differences in morphology between the UV and visible/near-IR images suggest three-dimensional variations in particle size and density across the impact site, which probably were induced during the explosion and associated events. At mid-infrared wavelengths the brightness temperature increased due to both an enhancement in the stratospheric NH 3 gas abundance and the physical temperature of the atmosphere. This high brightness temperature coincides with the center part of the impact site as seen with HST. This observation, combined with (published) numerical simulations of the Shoemaker-Levy 9 impacts on Jupiter and the Tunguska airburst on Earth, suggests that the downward jet from the terminal explosion probably penetrated down to the ˜700-mbar level.

  8. Measuring Extended Structure in Stars Using the Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Koresko, Chris; Colavita, M. Mark; Serabyn, Eugene; Booth, Andrew; Garcia, Jean

    2006-01-01

    The Keck Interferometer Nuller is designed to detect faint off-axis mid-infrared light a few tens to a few hundreds of milliarcseconds from a bright central star. The starlight is suppressed by destructive combination along the long (85 m) baseline, which produces a fringe spacing of 25 mas at a wavelength of 10 m, with the central null crossing the position of the star. The strong, variable mid-infrared background is subtracted using interferometric phase chopping along the short (5 m) baseline. This paper presents an overview of the observing and data reduction strategies used to produce a calibrated measurement of the off-axis light. During the observations, the instrument cycles rapidly through several calibration and measurement steps, in order to monitor and stabilize the phases of the fringes produced by the various baselines, and to derive the fringe intensity at the constructive peak and destructive null along the long baseline. The data analysis involves removing biases and coherently demodulating the short-baseline fringe with the long-baseline fringe tuned to alternate between constructive and destructive phases, combining the results of many measurements to improve the sensitivity, and estimating the part of the null leakage signal which is associated with the finite angular size of the central star. Comparison of the results of null measurements on science target and calibrator stars permits the instrumental leakage - the "system null leakage" - to be removed and the off-axis light to be measured.

  9. Global near-IR maps from Gemini-N and Keck in 2010, with a special focus on Janus Patera and Kanehekili Fluctus

    NASA Astrophysics Data System (ADS)

    de Pater, Imke; Davies, Ashley Gerard; McGregor, Alistair; Trujillo, Chad; Ádámkovics, Máté; Veeder, Glenn J.; Matson, Dennis L.; Leone, Giovanni

    2014-11-01

    We have imaged Io in the near-infrared (1-5 μm) with adaptive optics on the 10-m W.M. Keck II and the Gemini North telescopes. We have constructed global maps from the data taken in 2010. Although numerous hot spots are visible, the maps are dominated by two volcanic centers: Loki Patera and Kanehekili Fluctus. We have examined in detail the thermal emission from Janus Patera and Kanehekili Fluctus using images obtained between 2003 and 2010, and have created a timeline of volcanic activity at these locations utilizing data from a wide variety of sources. Based on our data and this timeline we find that the thermal emission from Janus Patera is relatively steady, indicative of an active lava lake. The thermal emission from Kanehekili Fluctus, however, is quite variable, and is indicative of the emplacement of extensive lava flows. In 2010, the thermal emission from this location was ∼10 times higher than ever seen before, indicative of a particularly voluminous eruption of lava.

  10. Keck Observations of the 2002-2003 Jovian Ring Plane Crossing

    SciTech Connect

    de Pater, I; Showalter, M R; Macintosh, B A

    2007-11-29

    We present new observations of Jupiter's ring system at a wavelength of 2.2 {micro}m obtained with the 10-m W. M. Keck telescopes on three nights during a ring plane crossing: UT 19 December 2002, and 22 and 26 January 2003. We used conventional imaging, plus adaptive optics on the last night. Here we present detailed radial profiles of the main ring, halo and gossamer rings, and interpret the data together with information extracted from radio observations of Jupiter's synchrotron radiation. The main ring is confined to a 800-km-wide annulus between 128,200 and 129,000 km, with a {approx} 5000 km extension on the inside. The normal optical depth is 8 x 10{sup -6}, 15% of which is provided by bodies with radii a {approx}> 5 cm. These bodies are as red as Metis. Half the optical depth, {tau} {approx} 4 x 10{sup -6}, is attributed to micron-sized dust, and the remaining {tau} {approx} 3 x 10{sup -6} to grains tens to hundreds of {micro}m in size. The inward extension consists of micron-sized (a {approx}< 10 {micro}m) dust, which probably migrates inward under Poynting-Robertson drag. The inner limit of this extension falls near the 3:2 Lorentz resonance (at orbital radius r = 122,400 km), and coincides with the outer limit of the halo. The gossamer rings appear to be radially confined, rather than broad sheets of material. The Amalthea ring is triangularly shaped, with a steep outer dropoff over {approx} 5000 km, extending a few 1000 km beyond the orbit of Amalthea, and a more gradual inner dropoff over 15,000-20,000 km. The inner edge is near the location of the synchronous orbit. The optical depth in the Amalthea ring is {approx} 5 x 10{sup -7}, up to 20% of which is comprised of macroscopic material. The optical depth in the Thebe ring is a factor of 3 smaller.

  11. A DETAILED GRAVITATIONAL LENS MODEL BASED ON SUBMILLIMETER ARRAY AND KECK ADAPTIVE OPTICS IMAGING OF A HERSCHEL-ATLAS SUBMILLIMETER GALAXY AT z = 4.243 {sup ,} {sup ,}

    SciTech Connect

    Bussmann, R. S.; Gurwell, M. A.; Fu Hai; Cooray, A.; Smith, D. J. B.; Bonfield, D.; Dunne, L.; Dye, S.; Eales, S.; Auld, R.; Baes, M.; Fritz, J.; Baker, A. J.; Cava, A.; Clements, D. L.; Dariush, A.; Coppin, K.; Dannerbauer, H.; De Zotti, G.; Hopwood, R.; and others

    2012-09-10

    We present high-spatial resolution imaging obtained with the Submillimeter Array (SMA) at 880 {mu}m and the Keck adaptive optics (AO) system at the K{sub S}-band of a gravitationally lensed submillimeter galaxy (SMG) at z = 4.243 discovered in the Herschel Astrophysical Terahertz Large Area Survey. The SMA data (angular resolution Almost-Equal-To 0.''6) resolve the dust emission into multiple lensed images, while the Keck AO K{sub S}-band data (angular resolution Almost-Equal-To 0.''1) resolve the lens into a pair of galaxies separated by 0.''3. We present an optical spectrum of the foreground lens obtained with the Gemini-South telescope that provides a lens redshift of z{sub lens} = 0.595 {+-} 0.005. We develop and apply a new lens modeling technique in the visibility plane that shows that the SMG is magnified by a factor of {mu} = 4.1 {+-} 0.2 and has an intrinsic infrared (IR) luminosity of L{sub IR} = (2.1 {+-} 0.2) Multiplication-Sign 10{sup 13} L{sub Sun }. We measure a half-light radius of the background source of r{sub s} = 4.4 {+-} 0.5 kpc which implies an IR luminosity surface density of {Sigma}{sub IR} (3.4 {+-} 0.9) Multiplication-Sign 10{sup 11} L{sub Sun} kpc{sup -2}, a value that is typical of z > 2 SMGs but significantly lower than IR luminous galaxies at z {approx} 0. The two lens galaxies are compact (r{sub lens} Almost-Equal-To 0.9 kpc) early-types with Einstein radii of {theta}{sub E1} 0.57 {+-} 0.01 and {theta}{sub E2} = 0.40 {+-} 0.01 that imply masses of M{sub lens1} = (7.4 {+-} 0.5) Multiplication-Sign 10{sup 10} M{sub Sun} and M{sub lens2} = (3.7 {+-} 0.3) Multiplication-Sign 10{sup 10} M{sub Sun }. The two lensing galaxies are likely about to undergo a dissipationless merger, and the mass and size of the resultant system should be similar to other early-type galaxies at z {approx} 0.6. This work highlights the importance of high spatial resolution imaging in developing models of strongly lensed galaxies discovered by Herschel.

  12. KECK NIRSPEC RADIAL VELOCITY OBSERVATIONS OF LATE-M DWARFS

    SciTech Connect

    Tanner, Angelle; White, Russel; Bailey, John; Blake, Cullen; Blake, Geoffrey; Cruz, Kelle; Burgasser, Adam J.; Kraus, Adam

    2012-11-15

    We present the results of an infrared spectroscopic survey of 23 late-M dwarfs with the NIRSPEC echelle spectrometer on the Keck II telescope. Using telluric lines for wavelength calibration, we are able to achieve measurement precisions of down to 45 m s{sup -1} for our late-M dwarfs over a one- to four-year long baseline. Our sample contains two stars with radial velocity (RV) variations of >1000 m s{sup -1}. While we require more measurements to determine whether these RV variations are due to unseen planetary or stellar companions or are the result of starspots known to plague the surface of M dwarfs, we can place upper limits of <40 M{sub J} sin i on the masses of any companions around those two M dwarfs with RV variations of <160 m s{sup -1} at orbital periods of 10-100 days. We have also measured the rotational velocities for all the stars in our late-M dwarf sample and offer our multi-order, high-resolution spectra over 2.0-2.4 {mu}m to the atmospheric modeling community to better understand the atmospheres of late-M dwarfs.

  13. Design and Implementation of Data Reduction Pipelines for the Keck Observatory Archive

    NASA Astrophysics Data System (ADS)

    Gelino, C. R.; Berriman, G. B.; Kong, M.; Laity, A. C.; Swain, M. A.; Campbell, R.; Goodrich, R. W.; Holt, J.; Lyke, J.; Mader, J. A.; Tran, H. D.; Barlow, T.

    2015-09-01

    The Keck Observatory Archive (KOA), a collaboration between the NASA Exoplanet Science Institute and the W. M. Keck Observatory, serves science and calibration data for all active and inactive instruments from the twin Keck Telescopes located near the summit of Mauna Kea, Hawaii. In addition to the raw data, we produce and provide quick look reduced data for four instruments (HIRES, LWS, NIRC2, and OSIRIS) so that KOA users can more easily assess the scientific content and the quality of the data, which can often be difficult with raw data. The reduced products derive from both publicly available data reduction packages (when available) and KOA-created reduction scripts. The automation of publicly available data reduction packages has the benefit of providing a good quality product without the additional time and expense of creating a new reduction package, and is easily applied to bulk processing needs. The downside is that the pipeline is not always able to create an ideal product, particularly for spectra, because the processing options for one type of target (eg., point sources) may not be appropriate for other types of targets (eg., extended galaxies and nebulae). In this poster we present the design and implementation for the current pipelines used at KOA and discuss our strategies for handling data for which the nature of the targets and the observers' scientific goals and data taking procedures are unknown. We also discuss our plans for implementing automated pipelines for the remaining six instruments.

  14. Science observations with the Keck Interferometer Nuller

    NASA Astrophysics Data System (ADS)

    Serabyn, E.; Booth, A.; Colavita, M. M.; Crawford, S.; Garcia, J.; Gathright, J.; Hrynevych, M.; Koresko, C.; Ligon, R.; Mennesson, B.; Panteleeva, T.; Ragland, S.; Summers, K.; Traub, W.; Tsubota, K.; Wetherell, E.; Wizinowich, P.; Woillez, J.

    2006-06-01

    The Keck Interferometer Nuller (KIN) is now largely in place at the Keck Observatory, and functionalities and performance are increasing with time. The main goal of the KIN is to examine nearby stars for the presence of exozodiacal emission, but other sources of circumstellar emission, such as disks around young stars, and hot exoplanets are also potential targets. To observe with the KIN in nulling mode, knowledge of the intrinsic source spectrum is essential, because of the wide variety of wavelengths involved in the various control loops - the AO system operates at visible wavelengths, the pointing loops use the J-band, the high-speed fringe tracker operates in the K-band, and the nulling observations take place in the N-band. Thus, brightness constraints apply at all of these wavelengths. In addition, source structure plays a role at both K-band and N-band, through the visibility. In this talk, the operation of the KIN is first briefly described, and then the sensitivity and performance of the KIN is summarized, with the aim of presenting an overview of the parameter space accessible to the nuller. Finally, some of the initial observations obtained with the KIN are described.

  15. The Team Keck Redshift Survey 2: MOSFIRE Spectroscopy of the GOODS-North Field

    NASA Astrophysics Data System (ADS)

    Wirth, Gregory D.; Trump, Jonathan R.; Barro, Guillermo; Guo, Yicheng; Koo, David C.; Liu, Fengshan; Kassis, Marc; Lyke, Jim; Rizzi, Luca; Campbell, Randy; Goodrich, Robert W.; Faber, S. M.

    2015-11-01

    We present the Team Keck Redshift Survey 2 (TKRS2), a near-infrared spectral observing program targeting selected galaxies within the CANDELS subsection of the GOODS-North Field. The TKRS2 program exploits the unique capabilities of the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE), which entered service on the Keck I telescope in 2012 and contributes substantially to the study of galaxy spectral features at redshifts inaccessible to optical spectrographs. The TKRS2 project targets 97 galaxies drawn from samples that include z ≈ 2 emission-line galaxies with features observable in the JHK bands as well as lower-redshift targets with features in the Y band. We present a detailed measurement of MOSFIRE’s sensitivity as a function of wavelength, including the effects of telluric features across the YJHK filters. The largest utility of our survey is in providing rest-frame-optical emission lines for z > 1 galaxies, and we demonstrate that the ratios of strong, optical emission lines of z ≈ 2 galaxies suggest the presence of either higher N/O abundances than are found in z ≈ 0 galaxies or low-metallicity gas ionized by an active galactic nucleus. We have released all TKRS2 data products into the public domain to allow researchers access to representative raw and reduced MOSFIRE spectra. Based in part on data obtained at the W. M. Keck Observatory, which operates as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The generous financial support of the W. M. Keck Foundation made the Observatory possible.

  16. Blue camera of the Keck cosmic web imager, fabrication and testing

    NASA Astrophysics Data System (ADS)

    Rockosi, Constance; Cowley, David; Cabak, Jerry; Hilyard, David; Pfister, Terry

    2016-08-01

    The Keck Cosmic Web Imager (KCWI) is a new facility instrument being developed for the W. M. Keck Observatory and funded for construction by the Telescope System Instrumentation Program (TSIP) of the National Science Foundation (NSF). KCWI is a bench-mounted spectrograph for the Keck II right Nasmyth focal station, providing integral field spectroscopy over a seeing-limited field up to 20" x 33" in extent. Selectable Volume Phase Holographic (VPH) gratings provide high efficiency and spectral resolution in the range of 1000 to 20000. The dual-beam design of KCWI passed a Preliminary Design Review in summer 2011. The detailed design of the KCWI blue channel (350 to 700 nm) is now nearly complete, with the red channel (530 to 1050 nm) planned for a phased implementation contingent upon additional funding. KCWI builds on the experience of the Caltech team in implementing the Cosmic Web Imager (CWI), in operation since 2009 at Palomar Observatory. KCWI adds considerable flexibility to the CWI design, and will take full advantage of the excellent seeing and dark sky above Mauna Kea with a selectable nod-and-shuffle observing mode. In this paper, models of the expected KCWI sensitivity and background subtraction capability are presented, along with a detailed description of the instrument design. The KCWI team is lead by Caltech (project management, design and implementation) in partnership with the University of California at Santa Cruz (camera optical and mechanical design) and the W. M. Keck Observatory (program oversight and observatory interfaces). The optical design of the blue camera for the Keck Cosmic Web Imager (KCWI) by Harland Epps of the University of California, Santa Cruz is a lens assembly consisting of eight spherical optical elements. Half the elements are calcium fluoride and all elements are air spaced. The design of the camera barrel is unique in that all the optics are secured in their respective cells with an RTV annulus without additional hardware

  17. HST and Keck Snapshot Surveys for Lensed Quasars

    NASA Astrophysics Data System (ADS)

    Gregg, M. D.; Becker, R. H.; Schechter, P. L.; White, R. L.; Wisotzki, L.

    2000-12-01

    Most theories of quasar lensing predict more close separation lenses than are presently known. Deciding whether this deficit is real or an observational selection effect is important for using lenses to constrain the intervening galaxy mass distribution or cosmological models. We are conducting two imaging surveys of bright quasars to search for new examples of gravitational lensing, particularly those with small image separations. After about 200 snapshots during Cycles 8 and 9, the program using the imaging capability of the Space Telescope Imaging Spectrograph (STIS) has found three certain lensed quasars, with separations of 0.64" (Gregg et al. 2000), 1.2", and a surprisingly large 3.4". There are several additional promising candidates. The other survey is being conducted with the Near InfraRed Camera (NIRC) at Keck Observatory. While the NIRC effort has not yet turned up any confirmed lensed quasars, the K-band imaging has detected the lensing galaxy in two of the new STIS systems. We will present our results and analysis to date, including additional ground based follow-up imaging and spectroscopy of the lensed and candidate systems. Support for this work is provided by NASA grants GO-8202 and GO-8631 from STScI, operated by AURA, Inc., under NASA contract NAS5-26555. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. Gregg, M.D., Wisotzki, L., Becker, R.H., Maza, J., Schechter, P. White, R.L., Brotherton, M.S., & Winn, J.N. 2000, AJ, 119, 2535.

  18. Overview of the control for the Keck Interferometer

    NASA Technical Reports Server (NTRS)

    Booth, A. J.; Eychaner, G.; Hovland, E.; Johnson, R.; Lupton, W.; Niessner, A.; Palmer, D.; Reder, L.; Rudeen, A.; Smythe, R.; Tsubota, K.

    2002-01-01

    This paper gives an overview of the control system that has been implemented for the single baseline operation of the Keck Interferometer and indicates how this will be extended to allow control of the future modes of the instrument.

  19. TWO EXOPLANETS DISCOVERED AT KECK OBSERVATORY

    SciTech Connect

    Valenti, Jeff A.; Fischer, Debra; Giguere, Matt; Isaacson, Howard; Marcy, Geoffrey W.; Howard, Andrew W.; Johnson, John A.; Henry, Gregory W.; Wright, Jason T.

    2009-09-10

    We present two exoplanets detected at Keck Observatory. HD 179079 is a G5 subgiant that hosts a hot Neptune planet with M sin i = 27.5 M{sub +} in a 14.48 days, low-eccentricity orbit. The stellar reflex velocity induced by this planet has a semiamplitude of K = 6.6 m s{sup -1}. HD 73534 is a G5 subgiant with a Jupiter-like planet of M sin i = 1.1 M{sub Jup} and K = 16 m s{sup -1} in a nearly circular 4.85 yr orbit. Both stars are chromospherically inactive and metal-rich. We discuss a known, classical bias in measuring eccentricities for orbits with velocity semiamplitudes, K, comparable to the radial velocity uncertainties. For exoplanets with periods longer than 10 days, the observed exoplanet eccentricity distribution is nearly flat for large amplitude systems (K > 80 m s{sup -1}), but rises linearly toward low eccentricity for lower amplitude systems (K > 20 m s{sup -1})

  20. Demonstration of a 10-m Solar Sail System

    NASA Technical Reports Server (NTRS)

    Murphy, David M.; Macy, Brian D.; Gaspar, James L.

    2004-01-01

    The NASA In-Space Propulsion (ISP) program has been sponsoring system design development and hardware demonstration activities of solar sail technology over the past 16 months. Efforts to validate by test a moderate-scale (10-m) 1/4 symmetry ground demonstration sail system are nearly complete. Results of testing and analytical model validation of component and assembly functional, strength, stiffness, shape, and dynamic behavior are discussed.

  1. VizieR Online Data Catalog: Team Keck Redshift Survey 2 (TKRS2) (Wirth+, 2015)

    NASA Astrophysics Data System (ADS)

    Wirth, G. D.; Trump, J. R.; Barro, G.; Guo, Y.; Koo, D. C.; Liu, F.; Kassis, M.; Lyke, J.; Rizzi, L.; Campbell, R.; Goodrich, R. W.; Faber, S. M.

    2016-04-01

    We present the Team Keck Redshift Survey 2 (TKRS2), a spectroscopic survey of 97 distant galaxies exploiting the capabilities of the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck I telescope at the W. M. Keck Observatory. MOSFIRE features a 2048*2048 pixel HAWAII-2RG HgCdTe detector array from Teledyne Imaging Sensors that couples high quantum efficiency with low noise and low dark current. The operating range of 0.97-2.41μm covers the YJHK infrared passbands, with wavelength coverage of 0.97-1.12μm in Y, 1.15-1.35μm in J, 1.47-1.80μm in H, and 1.95-2.40μm in K. The resolving power for the default slit width of 0.7" is R=3380 in Y, 3310 in J, 3660 in H, and 3620 in K, corresponding to full-width-half-maximum (FWHM) spectral resolutions of 3.1Å in Y, 3.7Å in J, 4.4Å in H, and 6.0Å in K. Our survey targets the south-central region of the GOODS-North survey field (Giavalisco et al. 2004, cat. II/261). We employed MOSFIRE to acquire spectra in the GOODS-North field over a series of partial nights spanning the period from 2012 November to 2013 May. We present the results of our survey in Table3 and on the website (http://arcoiris.ucsc.edu/TKRS2/) devoted to the survey. (1 data file).

  2. The Motions and Morphologies of cloud features on Neptune: continued monitoring with Keck Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Martin, S. C.; de Pater, I.; Gibbard, S. G.; Macintosh, B. A.; Roe, H. G.; Max, C. E.

    2002-09-01

    We present near infrared images taken in the H band (1.4-1.8 microns) using the newly commissioned NIRC2 at the W. M. Keck II telescope as part of a continuing program to monitor the atmospheric dynamics of Neptune using Adaptive Optics. These images with a resolution of .06 arcseconds reveal five infrared bright groups of features. Two groups of features (30-40 deg N and 20-50 deg S) are confined in latitude but span all longitudes creating bands around the planet. Small cloud morphology and relative motions in the wide Southern band (20-50 deg S) identify apparent cloud shearing events and differences in relative speeds within latitude bands. One localized group of features (30 deg N) shows interesting morphologies with marked departures from lines of latitude. Another localized group of South Polar features (70 deg S) show changes in morphology from a teardrop to a train of clouds to an arc of features during three years of observations. The final group of features is spatially diffuse and spans many latitude lines but is tightly confined in longitude. This research was supported in part by the STC Program of the National Science Foundation under Agreement No. AST-9876783, and in part under the auspices of the US Department of Energy at Lawrence Livermore National Laboratory, Univ. of Calif. under contract No. W-7405-Eng-48. Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  3. Space Telescope.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  4. THE TEAM KECK REDSHIFT SURVEY 2: MOSFIRE SPECTROSCOPY OF THE GOODS-NORTH FIELD

    SciTech Connect

    Wirth, Gregory D.; Kassis, Marc; Lyke, Jim; Rizzi, Luca; Campbell, Randy; Goodrich, Robert W.; Trump, Jonathan R.; Barro, Guillermo; Guo, Yicheng; Koo, David C.; Liu, Fengshan; Faber, S. M.

    2015-11-15

    We present the Team Keck Redshift Survey 2 (TKRS2), a near-infrared spectral observing program targeting selected galaxies within the CANDELS subsection of the GOODS-North Field. The TKRS2 program exploits the unique capabilities of the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE), which entered service on the Keck I telescope in 2012 and contributes substantially to the study of galaxy spectral features at redshifts inaccessible to optical spectrographs. The TKRS2 project targets 97 galaxies drawn from samples that include z ≈ 2 emission-line galaxies with features observable in the JHK bands as well as lower-redshift targets with features in the Y band. We present a detailed measurement of MOSFIRE’s sensitivity as a function of wavelength, including the effects of telluric features across the YJHK filters. The largest utility of our survey is in providing rest-frame-optical emission lines for z > 1 galaxies, and we demonstrate that the ratios of strong, optical emission lines of z ≈ 2 galaxies suggest the presence of either higher N/O abundances than are found in z ≈ 0 galaxies or low-metallicity gas ionized by an active galactic nucleus. We have released all TKRS2 data products into the public domain to allow researchers access to representative raw and reduced MOSFIRE spectra.

  5. Retrieving Neptune's aerosol properties from Keck OSIRIS observations. I. Dark regions

    NASA Astrophysics Data System (ADS)

    Luszcz-Cook, S. H.; de Kleer, K.; de Pater, I.; Adamkovics, M.; Hammel, H. B.

    2016-09-01

    We present and analyze three-dimensional data cubes of Neptune from the OSIRIS integral-field spectrograph on the 10-m W.M. Keck II telescope, from 26 July 2009. These data have a spatial resolution of 0.035/pixel and spectral resolution of R ∼3800 in the H (1.47-1.80 μm) and K (1.97-2.38 μm) broad bands. We focus our analysis on regions of Neptune's atmosphere that are near-infrared dark - that is, free of discrete bright cloud features. We use a forward model coupled to a Markov chain Monte Carlo algorithm to retrieve properties of Neptune's aerosol structure and methane profile above ∼4 bar in these near-infrared dark regions. We construct a set of high signal-to-noise spectra spanning a range of viewing geometries to constrain the vertical structure of Neptune's aerosols in a cloud-free latitude band from 2-12°N. We find that Neptune's cloud opacity at these wavelengths is dominated by a compact, optically thick cloud layer with a base near 3 bar. Using the pyDISORT algorithm for the radiative transfer and assuming a Henyey-Greenstein phase function, we observe this cloud to be composed of low albedo (single scattering albedo = 0.45-0.01+0.01), forward scattering (asymmetry parameter g = 0.50-0.02+0.02) particles, with an assumed characteristic size of ∼1μm. Above this cloud, we require an aerosol layer of smaller (∼0.1μm) particles forming a vertically extended haze, which reaches from the upper troposphere (0.59-0.03+0.04 bar) into the stratosphere. The particles in this haze are brighter (single scattering albedo = 0.91-0.05+0.06) and more isotropically scattering (asymmetry parameter g = 0.24-0.03+0.02) than those in the deep cloud. When we extend our analysis to 18 cloud-free locations from 20°N to 87°S, we observe that the optical depth in aerosols above 0.5 bar decreases by a factor of 2-3 or more at mid- and high-southern latitudes relative to low latitudes. We also consider Neptune's methane (CH4) profile, and find that our retrievals

  6. Heinrich Hertz Telescope

    NASA Astrophysics Data System (ADS)

    Baars, Jacob W.; Martin, Robert N.

    1998-07-01

    The Heinrich Hertz Telescope is a radio telescope dedicated to the observation of submillimeter wavelength radiation from celestial sources. It is a Cassegrain telescope with a diameter of 10 m and a reflector accuracy of about 17 micrometer, yielding an excellent performance at 350 micrometer, the shortest wavelength transmitted through the atmosphere. The reflector panels and the backup structure employ carbon-fiber reinforced plastic as basic material to achieve a lightweight, stiff construction with a very small coefficient of thermal expansion. This enables us to maintain full performance of the telescope in day time under solar illumination of the structure. In this paper, we describe the structural and material characteristics of the telescope. We also describe the holographic method which enables a measurement and setting of the reflector panels to an accuracy of 10 micrometer. The telescope is located on Mt. Graham in Eastern Arizona at an altitude of 3250 m, providing good submillimeter observing conditions, especially in the winter months. This is a collaborative effort of the Max-Planck- Institut fur Radioastronomie, Bonn, Germany and Steward Observatory, University of Arizona, Tucson, AZ.

  7. The W. M. Keck Observatory Infrared Vortex Coronagraph and a First Image of HIP 79124 B

    NASA Astrophysics Data System (ADS)

    Serabyn, E.; Huby, E.; Matthews, K.; Mawet, D.; Absil, O.; Femenia, B.; Wizinowich, P.; Karlsson, M.; Bottom, M.; Campbell, R.; Carlomagno, B.; Defrère, D.; Delacroix, C.; Forsberg, P.; Gomez Gonzalez, C.; Habraken, S.; Jolivet, A.; Liewer, K.; Lilley, S.; Piron, P.; Reggiani, M.; Surdej, J.; Tran, H.; Vargas Catalán, E.; Wertz, O.

    2017-01-01

    An optical vortex coronagraph has been implemented within the NIRC2 camera on the Keck II telescope and used to carry out on-sky tests and observations. The development of this new L‧-band observational mode is described, and an initial demonstration of the new capability is presented: a resolved image of the low-mass companion to HIP 79124, which had previously been detected by means of interferometry. With HIP 79124 B at a projected separation of 186.5 mas, both the small inner working angle of the vortex coronagraph and the related imaging improvements were crucial in imaging this close companion directly. Due to higher Strehl ratios and more relaxed contrasts in L‧ band versus H band, this new coronagraphic capability will enable high-contrast, small-angle observations of nearby young exoplanets and disks on a par with those of shorter-wavelength extreme adaptive optics coronagraphs.

  8. THE INNER KILOPARSEC OF Mrk 273 WITH KECK ADAPTIVE OPTICS

    SciTech Connect

    U, Vivian; Sanders, David; Kewley, Lisa; Medling, Anne; Max, Claire; Armus, Lee; Iwasawa, Kazushi; Evans, Aaron; Fazio, Giovanni

    2013-10-01

    There is X-ray, optical, and mid-infrared imaging and spectroscopic evidence that the late-stage ultraluminous infrared galaxy merger Mrk 273 hosts a powerful active galactic nucleus (AGN). However, the exact location of the AGN and the nature of the nucleus have been difficult to determine due to dust obscuration and the limited wavelength coverage of available high-resolution data. Here we present near-infrared integral-field spectra and images of the nuclear region of Mrk 273 taken with OSIRIS and NIRC2 on the Keck II Telescope with laser guide star adaptive optics. We observe three spatially resolved components, and analyze the nuclear molecular and ionized gas emission lines and their kinematics. We confirm the presence of the hard X-ray AGN in the southwest nucleus. In the north nucleus, we find a strongly rotating gas disk whose kinematics indicate a central black hole of mass 1.04 ± 0.1 × 10{sup 9} M{sub ☉}. The H{sub 2} emission line shows an increase in velocity dispersion along the minor axis in both directions, and an increased flux with negative velocities in the southeast direction; this provides direct evidence for a collimated molecular outflow along the axis of rotation of the disk. The third spatially distinct component appears to the southeast, 640 and 750 pc from the north and southwest nuclei, respectively. This component is faint in continuum emission but shows several strong emission line features, including [Si VI] 1.964 μm which traces an extended coronal-line region. The geometry of the [Si VI] emission combined with shock models and energy arguments suggest that [Si VI] in the southeast component must be at least partly ionized by the SW AGN or a putative AGN in the northern disk, either through photoionization or through shock-heating from strong AGN- and circumnuclear-starburst-driven outflows. This lends support to a scenario in which Mrk 273 may be a dual AGN system.

  9. Measuring Masses and Densities of Small Planets found by NASA's Kepler Spacecraft with Radial Velocity Measurements from Keck/HIRES

    NASA Astrophysics Data System (ADS)

    Isaacson, Howard T.; Marcy, G.; Rowe, J.; Kepler Team

    2013-06-01

    We use the Keck telescope and HIRES spectrometer to measure the masses of Kepler planet candidates. Analysis of 22 Kepler-identified planetary systems, holding 42 transiting planets (candidates) and 8 newly discovered non-transiting planets are presented herein. Combining the planet radius measurements from Kepler with mass measurements from Keck, we constrain the bulk density of short period planets that range in size from 1.0 to 3.0 Earth radii. Extensive ground based observations made by the Kepler Follow-up Program (KFOP) have provided extensive details about each KOI. Reconnaissance spectroscopy was used to refine the stellar and planet properties of each KOI at an early stage. SME spectral analysis and asteroseismology, when available, are used to obtain the final stellar properties. Adaptive Optics and speckle imaging constrain the presence of background eclipsing binaries that could masquerade as transiting planets. By combining ground based follow-up observations with Kepler photometry, a false positive probability is calculated for each KOI. An MCMC analysis that combines both Kepler photometry and Keck radial velocity measurements determines the final orbital parameters and planet properties for each system. The resulting mass vs. radius diagram for the planets reveals that radii increase with mass monotonically, well represented by a power law for the smallest planets. This M-R relationship offers key insights about the internal composition of the planets and the division between rocky and gaseous planets.

  10. 10m/500 Mbps WDM visible light communication systems.

    PubMed

    Lin, Wen-Yi; Chen, Chia-Yi; Lu, Hai-Han; Chang, Ching-Hung; Lin, Ying-Pyng; Lin, Huang-Chang; Wu, Hsiao-Wen

    2012-04-23

    A wavelength-division-multiplexing (WDM) visible light communiction (VLC) system employing red and green laser pointer lasers (LPLs) with directly modulating data signals is proposed and experimentally demonstrated. With the assistance of preamplifier and adaptive filter at the receiving sites, low bit error rate (BER) at 10 m/500 Mbps operation is obtained for each wavelength. The use of preamplifier and adaptive filter offer significant improvements for free-space transmission performance. Improved performance of BER of <10(-9), as well as better and clear eye diagram were achieved in our proposed WDM VLC systems. LPL features create a new category of good performance with high-speed data rate, long transmission length (>5m), as well as easy handling and installation. This proposed WDM VLC system reveals a prominent one to present its advancement in simplicity and convenience to be installed.

  11. The Core of NGC 6240 from Keck Adaptive Optics and HST NICMOS Observations

    SciTech Connect

    Max, C E; Canalizo, G; Macintosh, B A; Raschke, L; Whysong, D; Antonucci, R; Schneider, G

    2004-11-19

    We present results of near infrared imaging of the disk-galaxy-merger NGC 6240 using adaptive optics on the Keck II Telescope and reprocessed archival data from NICMOS on the Hubble Space Telescope. Both the North and South nuclei of NGC 6240 are clearly elongated, with considerable sub-structure within each nucleus. In K' band there are at least two point-sources within the North nucleus; we tentatively identify the south-western point-source within the North nucleus as the position of one of the two AGNs. Within the South nucleus, the northern subnucleus is more highly reddened. Based upon the nuclear separation measured at 5 GHz, we suggest that the AGN in the South nucleus is still enshrouded in dust at K' band, and is located slightly to the north of the brightest point in K' band. Within the South nucleus there is strong H{sub 2} 1-0 S(1) line emission from the northern sub-nucleus, contrary to the conclusions of previous seeing-limited observations. Narrowband H{sub 2} emission-line images show that a streamer or ribbon of excited molecular hydrogen connects the North and South nuclei. We suggest that this linear feature corresponds to a bridge of gas connecting the two nuclei, as seen in computer simulations of mergers. Many any point-like regions are seen around the two nuclei. These are most prominent at 1.1 microns with NICMOS, and in K'-band with Keck adaptive optics. We suggest that these point-sources represent young star clusters formed in the course of the merger.

  12. The Core of NGC 6240 from Keck Adaptive Optics and HST NICMOS Observations

    SciTech Connect

    Max, C E; Canalizo, G; Macintosh, B A; Raschke, L; Whysong, D; Antonucci, R; Schneider, G

    2004-06-28

    We present results of near infrared imaging of the disk-galaxy-merger NGC 6240 using adaptive optics on the Keck II Telescope and reprocessed archival data from NICMOS on the Hubble Space Telescope. Both the North and South nuclei of NGC 6240 are clearly elongated, with considerable sub-structure within each nucleus. In K' band there are at least two point-sources within the North nucleus; we tentatively identify the south-western point-source within the North nucleus as the position of one of the two AGNs. Within the South nucleus, the northern subnucleus is more highly reddened. Based upon the nuclear separation measured at 5 GHz, we suggest that the AGN in the South nucleus is still enshrouded in dust at K' band, and is located slightly to the north of the brightest point in K' band. Within the South nucleus there is strong H{sub 2} 1-0 S(1) line emission from the northern sub-nucleus, contrary to the conclusions of previous seeing-limited observations. Narrowband H{sub 2} emission-line images show that a streamer or ribbon of excited molecular hydrogen connects the North and South nuclei. We suggest that this linear feature corresponds to a bridge of gas connecting the two nuclei, as seen in computer simulations of mergers. Many point-like regions are seen around the two nuclei. These are most prominent at 1.1 microns with NICMOS, and in K'-band with Keck adaptive optics. We suggest that these point-sources represent star clusters formed in the course of the merger.

  13. Keck II laser guide star AO system and performance with the TOPTICA/MPBC laser

    NASA Astrophysics Data System (ADS)

    Chin, Jason C. Y.; Wizinowich, Peter; Wetherell, Ed; Lilley, Scott; Cetre, Sylvain; Ragland, Sam; Medeiros, Drew; Tsubota, Kevin; Doppmann, Greg; Otarola, Angel; Wei, Kai

    2016-07-01

    The Keck II Laser Guide Star (LGS) Adaptive Optics (AO) System was upgraded from a dye laser to a TOPTICA/MPBC Raman-Fibre Amplification (RFA) laser in December 2015. The W. M. Keck Observatory (WMKO) has been operating its AO system with a LGS for science since 2004 using a first generation 15 W dye laser. Using the latest diode pump laser technology, Raman amplification, and a well-tuned second harmonic generator (SHG), this Next Generation Laser (NGL) is able to produce a highly stable 589 nm laser beam with the required power, wavelength and mode quality. The beam's linear polarization and continuous wave format along with optical back pumping are designed to improve the sodium atom coupling efficiency over previously operated sodium-wavelength lasers. The efficiency and operability of the new laser has also been improved by reducing its required input power and cooling, size, and the manpower to operate and maintain it. The new laser has been implemented on the telescope's elevation ring with its electronics installed on a new Nasmyth sub-platform, with the capacity to support up to three laser systems for future upgrades. The laser is projected from behind the telescope's secondary mirror using the recently implemented center launch system (CLS) to reduce LGS spot size. We will present the new laser system and its performance with respect to power, stability, wavelength, spot size, optical repumping, polarization, efficiency, and its return with respect to pointing alignment to the magnetic field. Preliminary LGSAO performance is presented with the system returning to science operations. We will also provide an update on current and future upgrades at the WMKO.

  14. Space Telescopes

    NASA Technical Reports Server (NTRS)

    Clampin, Mark; Flanagan, Kathryn A.

    2012-01-01

    Space telescopes have been a dominant force in astrophysics and astronomy over the last two decades. As Lyman Spitzer predicted in 1946, space telescopes have opened up much of the electromagnetic spectrum to astronomers, and provided the opportunity to exploit the optical performance of telescopes uncompromised by the turbulent atmosphere. This special section of Optical Engineering is devoted to space telescopes. It focuses on the design and implementation of major space observatories from the gamma-ray to far-infrared, and highlights the scientific and technical breakthroughs enabled by these telescopes. The papers accepted for publication include reviews of major space telescopes spanning the last two decades, in-depth discussions of the design considerations for visible and x-ray telescopes, and papers discussing concepts and technical challenges for future space telescopes.

  15. Laboratory performance of the Keck interferometer nulling beam combiner

    NASA Technical Reports Server (NTRS)

    Mennesson, B.; Crawford, S. L.; Serabyn, E.; Martin, S.; Creech-Eakman, M.; Hardy, G.

    2003-01-01

    Now that regular visibility squared measurements are routinely achieved, mid-infrared nulling is the next observing mode to be implemented on the Keck Interferometer. This mode's main objective is the characterization of exo-zodiacal dust disks around nearby main sequence stars in support of the TPF space mission. Keck Nuller also shares numerious characteristics with an interferometric TPF, and will then serve as a technical precursor for this mission. We report here the results obtained in the laboratory with the KI mid-IR nulling beam combiner, which is based on a dual polarization Modified Mach Zender combiner and dispersion and achromatic nulling through zinc-selenide dielectric plates.

  16. The South Pole Telescope

    SciTech Connect

    Ruhl, J.E.; Ade, P.A.R.; Carlstrom, J.E.; Cho, H.M.; Crawford,T.; Dobbs, M.; Greer, C.H.; Halverson, N.W.; Holzapfel, W.L.; Lanting,T.M.; Lee, A.T.; Leitch, E.M.; Leong, J.; Lu, W.; Lueker, M.; Mehl, J.; Meyer, S.S.; Mohr, J.J.; Padin, S.; Plagge, T.; Pryke, C.; Runyan, M.C.; Schwan, D.; Sharp, M.K.; Spieler, H.; Staniszewski, Z.; Stark, A.A.

    2004-11-04

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10 m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency-multiplexed readouts. The first key project will be to conduct a survey over 4000 degrees for galaxy clusters using the Sunyaev-Zeldovich Effect. This survey should find many thousands of clusters with a mass selection criteria that is remarkably uniform with redshift. Armed with redshifts obtained from optical and infrared follow-up observations, it is expected that the survey will enable significant constraints to be placed on the equation of state of the dark energy.

  17. Control and alignment of segmented-mirror telescopes: matrices, modes, and error propagation.

    PubMed

    Chanan, Gary; MacMartin, Douglas G; Nelson, Jerry; Mast, Terry

    2004-02-20

    Starting from the successful Keck telescope design, we construct and analyze the control matrix for the active control system of the primary mirror of a generalized segmented-mirror telescope, with up to 1000 segments and including an alternative sensor geometry to the one used at Keck. In particular we examine the noise propagation of the matrix and its consequences for both seeing-limited and diffraction-limited observations. The associated problem of optical alignment of such a primary mirror is also analyzed in terms of the distinct but related matrices that govern this latter problem.

  18. BICEP3 performance overview and planned Keck Array upgrade

    NASA Astrophysics Data System (ADS)

    Grayson, J. A.; Ade, P. A. R.; Ahmed, Z.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Boenish, H.; Bowens-Rubin, R.; Buder, I.; Bullock, E.; Buza, V.; Connors, J.; Filippini, J. P.; Fliescher, S.; Halpern, M.; Harrison, S.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Monticue, V.; Namikawa, T.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Pryke, C.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sorenson, C.; Sheehy, C. D.; Staniszewski, Z. K.; Steinbach, B.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Tucker, C.; Turner, A. D.; Vieregg, A. G.; Wandui, A.; Weber, A. C.; Wiebe, D. V.; Willmert, J.; Wu, W. L. K.; Yoon, K. W.

    2016-07-01

    Bicep3 is a 520mm aperture, compact two-lens refractor designed to observe the polarization of the cosmic microwave background (CMB) at 95 GHz. Its focal plane consists of modularized tiles of antenna-coupled transition edge sensors (TESs), similar to those used in Bicep2 and the Keck Array. The increased per-receiver optical throughput compared to Bicep2/Keck Array, due to both its faster f=1:7 optics and the larger aperture, more than doubles the combined mapping speed of the Bicep/Keck program. The Bicep3 receiver was recently upgraded to a full complement of 20 tiles of detectors (2560 TESs) and is now beginning its second year of observation (and first science season) at the South Pole. We report on its current performance and observing plans. Given its high per-receiver throughput while maintaining the advantages of a compact design, Bicep3- class receivers are ideally suited as building blocks for a 3rd-generation CMB experiment, consisting of multiple receivers spanning 35 GHz to 270 GHz with total detector count in the tens of thousands. We present plans for such an array, the new "BICEP Array" that will replace the Keck Array at the South Pole, including design optimization, frequency coverage, and deployment/observing strategies.

  19. Spatially Resolved Emission of a High-redshift DLA Galaxy with the Keck/OSIRIS IFU

    NASA Astrophysics Data System (ADS)

    Jorgenson, Regina A.; Wolfe, Arthur M.

    2014-04-01

    We present the first Keck/OSIRIS infrared IFU observations of a high-redshift damped Lyα (DLA) galaxy detected in the line of sight to a background quasar. By utilizing the Laser Guide Star Adaptive Optics to reduce the quasar point-spread function to FWHM ~ 0.''15, we were able to search for and map the foreground DLA emission free from the quasar contamination. We present maps of the Hα and [O III] λλ5007, 4959 emission of DLA 2222-0946 at a redshift of z ~ 2.35. From the composite spectrum over the Hα emission region, we measure a star formation rate of 9.5 ± 1.0 M ⊙ yr-1 and a dynamical mass of M dyn = 6.1 × 109 M ⊙. The average star formation rate surface density is langΣSFRrang = 0.55 M ⊙ yr-1 kpc-2, with a central peak of 1.7 M ⊙ yr-1 kpc-2. Using the standard Kennicutt-Schmidt relation, this corresponds to a gas mass surface density of Σgas = 243 M ⊙ pc-2. Integrating over the size of the galaxy, we find a total gas mass of M gas = 4.2 × 109 M ⊙. We estimate the gas fraction of DLA 2222-0946 to be f gas ~ 40%. We detect [N II] λ6583 emission at 3σ significance with a flux corresponding to a metallicity of 75% solar. Comparing this metallicity with that derived from the low-ion absorption gas ~6 kpc away, ~30% solar, indicates possible evidence for a metallicity gradient or enriched in/outflow of gas. Kinematically, both Hα and [O III] emission show relatively constant velocity fields over the central galactic region. While we detect some red and blueshifted clumps of emission, they do not correspond with rotational signatures that support an edge-on disk interpretation. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  20. Generalized atmospheric dispersion correctors for Thirty Meter Telescope

    NASA Astrophysics Data System (ADS)

    Sutin, Brian M.

    2016-08-01

    The Thirty Meter Telescope (TMT) is unbaffled and has stability requirements tighter than the previous generation of 10- m class telescopes, leading to tougher requirements on atmospheric dispersion correctors (ADCs). Since instruments are internally baffled, ADCs may no longer shift the position of the telescope exit pupil. Designs that control pupil position are explored.

  1. Characterizing site specific considerations for protecting aircraft during LGS operations at W. M. Keck Observatory

    NASA Astrophysics Data System (ADS)

    Stomski, Paul J., Jr.; Campbell, Randy; McCann, Kevin; Shimko, Steve

    2010-07-01

    W. M. Keck Observatory (WMKO) routinely operates laser guide star (LGS) Adaptive Optics (AO) systems at the telescope facility on the Big Island of Hawaii. One of the operational requirements for the LGS system is that a safety system to prevent nearby aircraft from being adversely affected by the laser must be provided. We will support operations in the near term with human aircraft spotters until we can successfully develop and get the appropriate approvals needed for an Automated, Integrated and Reliable System for an Aircraft Friendly Environment (AIRSAFE). This report describes some of the preliminary requirements development work at WMKO in support of the future development of AIRSAFE. We discuss the results of recent work to characterize site specific considerations that impact requirements development. The site specific considerations include the proximity of WMKO laser operations to nearby commercial airports, the implications of military operations in the area and the character of the air traffic volume and flight patterns over the telescope facility. Finally, we discuss how the design and implementation of AIRSAFE will be impacted by these site specific considerations.

  2. Properties and dynamics of Jupiter's gossamer rings from Galileo, Voyager, Hubble and Keck images

    NASA Astrophysics Data System (ADS)

    Showalter, Mark R.; de Pater, Imke; Verbanac, Giuli; Hamilton, Douglas P.; Burns, Joseph A.

    2008-05-01

    We present a comprehensive examination of Jupiter's "gossamer" rings based on images from Voyager, Galileo, the Hubble Space Telescope and the W.M. Keck Telescope. We compare our results to the simple dynamical model of Burns et al. [Burns, J.A., Showalter, M.R., Hamilton, D.P., Nicholson, P.D., de Pater, I., Ockert-Bell, M., Thomas, P., 1999. Science 284, 1146-1150] in which dust is ejected from Amalthea and Thebe and then evolves inward under Poynting-Robertson drag. The ring follows many predictions of the model rather well, including a linear reduction in thickness with decreasing radius. However, some deviations from the model are noted. For example, additional material appears to be concentrated just interior to the orbits of the two moons. At least in the case of Amalthea's ring, that material is in the same orbital plane as Amalthea's inclined orbit and may be trapped at the Lagrange points. Thebe's ring shows much larger vertical excursions from the model, which may be related to perturbations by several strong Lorentz resonances. Photometry is consistent with the dust obeying a relatively flat power-law size distribution, very similar to dust in the main ring. However, the very low backscatter reflectivity of the ring, and the flat phase curve of the ring at low phase angles, require that the ring be composed of distinctly non-spherical particles.

  3. Constraining the Bulk Density of 10m-Class Near-Earth Asteroid 2012 LA

    NASA Astrophysics Data System (ADS)

    Mommert, Michael; Hora, Joseph; Farnocchia, Davide; Trilling, David; Chesley, Steve; Harris, Alan; Mueller, Migo; Smith, Howard

    2016-08-01

    The physical properties of near-Earth asteroids (NEAs) provide important hints on their origin, as well as their past physical and orbital evolution. Recent observations seem to indicate that small asteroids are different than expected: instead of being monolithic bodies, some of them instead resemble loose conglomerates of smaller rocks, so called 'rubble piles'. This is surprising, since self-gravitation is practically absent in these bodies. Hence, bulk density measurements of small asteroids, from which their internal structure can be estimated, provide unique constraints on asteroid physical models, as well as models for asteroid evolution. We propose Spitzer Space Telescope observations of 10 m-sized NEA 2012 LA, which will allow us to constrain the diameter, albedo, bulk density, macroporosity, and mass of this object. We require 30 hrs of Spitzer time to detect our target with a minimum SNR of 3 in CH2. In order to interpret our observational results, we will use the same analysis technique that we used in our successful observations and analyses of tiny asteroids 2011 MD and 2009 BD. Our science goal, which is the derivation of the target's bulk density and its internal structure, can only be met with Spitzer. Our observations will produce only the third comprehensive physical characterization of an asteroid in the 10m size range (all of which have been carried out by our team, using Spitzer). Knowledge of the physical properties of small NEAs, some of which pose an impact threat to the Earth, is of importance for understanding their evolution and estimating the potential of destruction in case of an impact, as well as for potential manned missions to NEAs for either research or potential commercial uses.

  4. Telescope Equipment

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Renaissance Telescope for high resolution and visual astronomy has five 82-degree Field Tele-Vue Nagler Eyepieces, some of the accessories that contribute to high image quality. Telescopes and eyepieces are representative of a family of optical equipment manufactured by Tele-Vue Optics, Inc.

  5. Performance of the Keck Observatory adaptive optics system

    SciTech Connect

    van Dam, M A; Mignant, D L; Macintosh, B A

    2004-01-19

    In this paper, the adaptive optics (AO) system at the W.M. Keck Observatory is characterized. The authors calculate the error budget of the Keck AO system operating in natural guide star mode with a near infrared imaging camera. By modeling the control loops and recording residual centroids, the measurement noise and band-width errors are obtained. The error budget is consistent with the images obtained. Results of sky performance tests are presented: the AO system is shown to deliver images with average Strehl ratios of up to 0.37 at 1.58 {micro}m using a bright guide star and 0.19 for a magnitude 12 star.

  6. Extrazodiacal Light Detection Prospects with the Keck Interferometer

    NASA Technical Reports Server (NTRS)

    Serabyn, E.

    1999-01-01

    The Keck interferometer currently under development will include a midinfrared nulling experiment that is designed to search for extrazodiacal dust around nearby stars. The potential of this technique, as wel1 as the basic experimental approach, will be discussed. The initial goal is to search for extrazodiacal emission around nearby stars at the 10-solar zodi-equivalent level, with a long-term goal of I solar zodi.

  7. A high-precision angle encoder for a 10-m submillimeter antenna

    NASA Astrophysics Data System (ADS)

    Ukita, Nobuharu; Ezawa, Hajime; Mimura, Hisashi; Suganuma, Akira; Kitazawa, Kanji; Masuda, Tadashi; Kawaguchi, Noboru; Sugiyama, Ryuichi; Miyawaki, Keizou

    2001-03-01

    We report measurements of angle error characteristics of new high-precision multi-speed resolvers developed for a 10-m submillimeter telescope of Nobeyama Radio Observatory. We have found the resolvers have an accuracy of 0.03" rms and 0.26" peak-to-peak, which is well below the error budget assigned to the angle encoder in the LMSA/ALMA project (0.15 - 0.2"). The error pattern in the raw readout had simple characteristics and was only composed of a few Fourier components which are associated with the number of winding poles and core slot number of stator. The 4" peak-to-peak error in the raw readout is reduced to less than 1/15 by the PROM correction. We have also found that shaft misalignment causes only small changes of error pattern (0.08" error per 0.10 mm shaft misalignment), which enables us to install the resolver simply by the fitting. The temperature dependence of error pattern also seems to be small enough for the operation temperature range specified in the project.

  8. A STELLAR DYNAMICAL MASS MEASUREMENT OF THE BLACK HOLE IN NGC 3998 FROM KECK ADAPTIVE OPTICS OBSERVATIONS

    SciTech Connect

    Walsh, Jonelle L.; Van den Bosch, Remco C. E.; Barth, Aaron J.; Sarzi, Marc

    2012-07-01

    We present a new stellar dynamical mass measurement of the black hole in the nearby, S0 galaxy NGC 3998. By combining laser guide star adaptive optics observations obtained with the OH-Suppressing Infrared Imaging Spectrograph on the Keck II telescope with long-slit spectroscopy from the Hubble Space Telescope and the Keck I telescope, we map out the stellar kinematics on both small spatial scales, well within the black hole sphere of influence, and large scales. We find that the galaxy is rapidly rotating and exhibits a sharp central peak in the velocity dispersion. Using the kinematics and the stellar luminosity density derived from imaging observations, we construct three-integral, orbit-based, triaxial stellar dynamical models. We find the black hole has a mass of M{sub BH} = (8.1{sup +2.0}{sub -1.9}) Multiplication-Sign 10{sup 8} M{sub Sun }, with an I-band stellar mass-to-light ratio of M/L = 5.0{sup +0.3}{sub -0.4} M{sub Sun }/L{sub Sun} (3{sigma} uncertainties), and that the intrinsic shape of the galaxy is very round, but oblate. With the work presented here, NGC 3998 is now one of a very small number of galaxies for which both stellar and gas dynamical modeling have been used to measure the mass of the black hole. The stellar dynamical mass is nearly a factor of four larger than the previous gas dynamical black hole mass measurement. Given that this cross-check has so far only been attempted on a few galaxies with mixed results, carrying out similar studies in other objects is essential for quantifying the magnitude and distribution of the cosmic scatter in the black hole mass-host galaxy relations.

  9. SNAP Telescope

    NASA Astrophysics Data System (ADS)

    Lampton, Michael L.; Akerlof, Carl W.; Aldering, Greg; Amanullah, R.; Astier, Pierre; Barrelet, E.; Bebek, Christopher; Bergstrom, Lars; Bercovitz, John; Bernstein, G.; Bester, Manfred; Bonissent, Alain; Bower, C. R.; Carithers, William C., Jr.; Commins, Eugene D.; Day, C.; Deustua, Susana E.; DiGennaro, Richard S.; Ealet, Anne; Ellis, Richard S.; Eriksson, Mikael; Fruchter, Andrew; Genat, Jean-Francois; Goldhaber, Gerson; Goobar, Ariel; Groom, Donald E.; Harris, Stewart E.; Harvey, Peter R.; Heetderks, Henry D.; Holland, Steven E.; Huterer, Dragan; Karcher, Armin; Kim, Alex G.; Kolbe, William F.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, Michael E.; Levin, Daniel S.; Linder, Eric V.; Loken, Stewart C.; Malina, Roger; Massey, R.; McKay, Timothy; McKee, Shawn P.; Miquel, Ramon; Mortsell, E.; Mostek, N.; Mufson, Stuart; Musser, J. A.; Nugent, Peter E.; Oluseyi, Hakeem M.; Pain, Reynald; Palaio, Nicholas P.; Pankow, David H.; Perlmutter, Saul; Pratt, R.; Prieto, Eric; Refregier, Alexandre; Rhodes, J.; Robinson, Kem E.; Roe, N.; Sholl, Michael; Schubnell, Michael S.; Smadja, G.; Smoot, George F.; Spadafora, A.; Tarle, Gregory; Tomasch, Andrew D.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, Guobin

    2002-12-01

    The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.

  10. SNAP telescope

    SciTech Connect

    Lampton, Michael L.; Akerlof, C.W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Bercovitz, J.; Bernstein, G.; Bester, M.; Bonissent, A.; Bower, C.; Carithers Jr., W.C.; Commins, E.D.; Day, C.; Deustua, S.E.; DiGennaro, R.; Ealet, A.; Ellis,R.S.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar,A.; Groom, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Holland,S.E.; Huterer, D.; Karcher, A.; Kim, A.G.; Kolbe, W.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, M.E.; Levin, D.S.; Linder, E.V.; Loken,S.C.; Malina, R.; Massey, R.; McKay, T.; McKee, S.P.; Miquel, R.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi,H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto,E.; Refregier, A.; Rhodes, J.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tarle, G.; Tomasch,A.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, G.; Wang, G.

    2002-07-29

    The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.

  11. Teaching Telescopes

    ERIC Educational Resources Information Center

    Reid, John S.

    1974-01-01

    Discusses experience of teaching optical experiments with emphasis upon the student's design and construction of refracting and reflecting telescopes. Concludes that the student's interest and acquired knowledge are greatly enhanced through the use of realistic experiments. (CC)

  12. Space Telescopes

    DTIC Science & Technology

    2010-01-01

    the Kirkpatrick–Baez type systems and the focussing colli- mator or ‘ lobster -eye’ systems. 1http://henke.lbl.gov/optical constants/ 176 9. Space...mirror requires a longer telescope. Focussing collimator or ‘ lobster -eye’ telescopes The Wolter and the Kirkpatrick–Baez systems have in common a...9.13: Flat-mirror two-dimensional focussing collimator or detached lobster - eye configuration (Schmidt 1975). within one tube but from adjacent walls a

  13. Analysis of the Naval Observatory Flagstaff Station 1-m Telescope using Annular Zernike Polynomials

    DTIC Science & Technology

    2003-01-01

    University in Flag- staff. From 1993 to 2000 he was an optical engineer and manager of the telescope optics group at Keck Observatory on Mauna Kea , Hawaii...Analysis of the Naval Observatory Flagstaff Station 1-m telescope using annular Zernike polynomials Sergio R. Restaino Naval Research Laboratory...Mining and Technology Electrical Engineering Department 801 Leroy Place Socorro, New Mexico 87801 Michael DiVittorio U.S. Naval Observatory Flagstaff

  14. MEGARA optical design: the new integral field unit and multi-object spectrograph for the GTC 10m telescope

    NASA Astrophysics Data System (ADS)

    García-Vargas, María. Luisa; Sánchez-Blanco, Ernesto; Carrasco, Esperanza; Gil de Paz, Armando; Páez, Gonzalo; Pérez, Ana; Gallego, Jesús; Sánchez, Francisco; Vílchez, José M.

    2012-12-01

    We describe the optical design of MEGARA, the future optical Integral Field Unit (IFU) and Multi-Object Spectrograph (MOS) for the 10.4-m Gran Telescopio CANARIAS (GTC). MEGARA is being built by a Consortium of public research institutions led by the Universidad Complutense de Madrid (UCM, Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain) and UPM (Spain).

  15. Hubble and Keck team up to find farthest known galaxy in the Universe

    NASA Astrophysics Data System (ADS)

    2004-02-01

    -angle image spans 0.4 by 0.4 degrees and was taken by the 12k camera on Canada-France-Hawaii Telescope on Mauna Kea, Hawaii, United States. The image is composited by three exposures through blue (B), red (R), and infrared (I) filters. The primeval galaxy was identified by combining the power of the NASA/ESA Hubble Space Telescope and CARA's W. M. Keck Telescopes on Mauna Kea in Hawaii. These great observatories got a boost from the added magnification of a natural ‘cosmic gravitational lens’ in space that further amplifies the brightness of the distant object. The newly discovered galaxy is likely to be a young galaxy shining during the end of the so-called "Dark Ages" - the period in cosmic history which ended with the first galaxies and quasars transforming opaque, molecular hydrogen into the transparent, ionized Universe we see today. The new galaxy was detected in a long exposure of the nearby cluster of galaxies Abell 2218, taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. This cluster is so massive that the light of distant objects passing through the cluster actually bends and is amplified, much as a magnifying glass bends and magnifies objects seen through it. Such natural gravitational ‘telescopes’ allow astronomers to see extremely distant and faint objects that could otherwise not be seen. The extremely faint galaxy is so far away its visible light has been stretched into infrared wavelengths, making the observations particularly difficult. "As we were searching for distant galaxies magnified by Abell 2218, we detected a pair of strikingly similar images whose arrangement and colour indicate a very distant object," said astronomer Jean-Paul Kneib (Observatoire Midi-Pyrénées and California Institute of Technology), who is lead author reporting the discovery in a forthcoming article in the Astrophysical Journal. Analysis of a sequence of Hubble images indicate the object lies between a redshift of 6.6 and 7.1, making it the

  16. Why systems engineering on telescopes?

    NASA Astrophysics Data System (ADS)

    Swart, Gerhard P.; Meiring, Jacobus G.

    2003-02-01

    Although Systems Engineering has been widely applied to the defence industry, many other projects are unaware of its potential benefits when correctly applied, assuming that it is an expensive luxury. It seems that except in a few instances, telescope projects are no exception, prompting the writing of this paper. The authors postulate that classical Systems Engineering can and should be tailored, and then applied to telescope projects, leading to cost, schedule and technical benefits. This paper explores the essence of Systems Engineering and how it can be applied to any complex development project. The authors cite real-world Systems Engineering examples from the Southern African Large Telescope (SALT). The SALT project is the development and construction of a 10m-class telescope at the price of a 4m telescope. Although SALT resembles the groundbreaking Hobby-Eberly Telescope (HET) in Texas, the project team are attempting several challenging changes to the original design, requiring a focussed engineering approach and discernment in the definition of the telescope requirements. Following a tailored Systems Engineering approach on this project has already enhanced the quality of decisions made, improved the fidelity of contractual specifications for subsystems, and established criteria testing their performance. Systems Engineering, as applied on SALT, is a structured development process, where requirements are formally defined before the award of subsystem developmental contracts. During this process conceptual design, modeling and prototyping are performed to ensure that the requirements were realistic and accurate. Design reviews are held where the designs are checked for compliance with the requirements. Supplier factory and on-site testing are followed by integrated telescope testing, to verify system performance against the specifications. Although the SALT project is still far from completion, the authors are confident that the present benefits from

  17. Remote observing with the Nickel Telescope at Lick Observatory

    NASA Astrophysics Data System (ADS)

    Grigsby, Bryant; Chloros, Konstantinos; Gates, John; Deich, William T. S.; Gates, Elinor; Kibrick, Robert

    2008-07-01

    We describe a project to enable remote observing on the Nickel 1-meter Telescope at Lick Observatory. The purpose was to increase the subscription rate and create more economical means for graduate- and undergraduate students to observe with this telescope. The Nickel Telescope resides in a 125 year old dome on Mount Hamilton. Remote observers may work from any of the University of California (UC) remote observing facilities that have been created to support remote work at both Keck Observatory and Lick Observatory. The project included hardware and software upgrades to enable computer control of all equipment that must be operated by the astronomer; a remote observing architecture that is closely modeled on UCO/Lick's work to implement remote observing between UC campuses and Keck Observatory; new policies to ensure safety of Observatory staff and equipment, while ensuring that the telescope subsystems would be suitably configured for remote use; and new software to enforce the safety-related policies. The results increased the subscription rate from a few nights per month to nearly full subscription, and has spurred the installation of remote observing sites at more UC campuses. Thanks to the increased automation and computer control, local observing has also benefitted and is more efficient. Remote observing is now being implemented for the Shane 3- meter telescope.

  18. Observational constraints on the formation and evolution of the Milky Way nuclear star cluster with Keck and Gemini

    NASA Astrophysics Data System (ADS)

    Do, Tuan; Ghez, Andrea; Morris, Mark; Lu, Jessica; Chappell, Samantha; Feldmeier-Krause, Anja; Kerzendorf, Wolfgang; Martinez, Gregory David; Murray, Norm; Winsor, Nathan

    2017-01-01

    We summarize work on the central parsec of the Galactic center based on imaging and spectroscopic observations at the Keck and Gemini telescopes. These observations include stellar positions in two dimension and the velocity in three dimensions. Spectroscopic observations also enables measurements of the physical properties of individual stars, such as the spectral type and in some cases the effective temperature, metallicity, and surface gravity. These observations show a complex stellar population with a young (4-6 Myr) compact star cluster in the central 0.5 pc embedded in in an older and much more massive nuclear star cluster. Surprisingly, the old late-type giants do not show a cusp profile as long been expected from theoretical work. The majority of the stars have higher than solar metallicity, with only about 6% of the stars having [M/Fe] < -0.5, which is consistent with an origin from the MW disk.

  19. The low-resolution imaging spectrograph red channel CCD upgrade: fully depleted, high-resistivity CCDs for Keck

    NASA Astrophysics Data System (ADS)

    Rockosi, C.; Stover, R.; Kibrick, R.; Lockwood, C.; Peck, M.; Cowley, D.; Bolte, M.; Adkins, S.; Alcott, B.; Allen, S. L.; Brown, B.; Cabak, G.; Deich, W.,; Hilyard, D.,; Kassis, M.,; Lanclos, K.,; Lewis, J.,; Pfister, T.,; Phillips, A.,; Robinson, L.,; Saylor, M.,; Thompson, M.,; Ward, J.,; Wei, M.,; Wright, C.,

    2010-07-01

    A mosaic of two 2k x 4k fully depleted, high resistivity CCD detectors was installed in the red channel of the Low Resolution Imaging Spectrograph for the Keck-I Telescope in June, 2009 replacing a monolithic Tektronix/SITe 2k x 2k CCD. These CCDs were fabricated at Lawrence Berkeley National Laboratory (LBNL) and packaged and characterized by UCO/Lick Observatory. Major goals of the detector upgrade were increased throughput and reduced interference fringing at wavelengths beyond 800 nm, as well as improvements in the maintainability and serviceability of the instrument. We report on the main features of the design, the results of optimizing detector performance during integration and testing, as well as the throughput, sensitivity and performance of the instrument as characterized during commissioning.

  20. KECK-I MOSFIRE SPECTROSCOPY OF THE z {approx} 12 CANDIDATE GALAXY UDFj-39546284

    SciTech Connect

    Capak, P.; Faisst, A.; Tacchella, S.; Carollo, M.; Vieira, J. D.; Scoville, N. Z.

    2013-08-10

    We report the results of deep (4.6 hr) H-band spectroscopy of the well studied z {approx} 12 H-band dropout galaxy candidate UDFj-39546284 with MOSFIRE on Keck-I. These data reach a sensitivity of 5-10 Multiplication-Sign 10{sup -19} erg s{sup -1} cm{sup -2} per 4.4 A resolution element between sky lines. Previous papers have argued that this source could either be a large equivalent width line emitting galaxy at 2 < z < 3.5 or a luminous galaxy at z {approx} 12. We find a 2.2{sigma} peak associated with a line candidate in deep Hubble Space Telescope Wide-Field Camera 3 Infrared grism observations, but at a lower flux than expected. After considering several possibilities, we conclude these data cannot conclusively confirm or reject the previous line detection, and significantly deeper spectroscopic observations are required. We also search for low-redshift emission lines in 10 other 7 < z < 10 z, Y, and J-dropout candidates in our mask and find no significant detections.

  1. Multifrequency Beam Characterization and Systematics for the Keck Array, BICEP3, and Future CMB Polarization Experiments

    NASA Astrophysics Data System (ADS)

    Karkare, Kirit S.; BICEP/Keck Array Collaboration

    2017-01-01

    The BICEP/Keck Array cosmic microwave background (CMB) polarization experiments located at the South Pole are a series of small-aperture refracting telescopes focused on the degree-scale B-mode signature of inflationary gravitational waves. These highly-targeted experiments have produced the world's deepest maps of CMB polarization, leading to the most stringent constraints on the tensor-to-scalar ratio to date: sigma(r) = 0.024 and r < 0.09 from B-modes alone, and r < 0.07 in combination with other datasets. These constraints will rapidly improve with upcoming measurements at the multiple frequencies needed to separate Galactic foregrounds from the CMB, and in combination with higher-resolution experiments to remove B-modes induced by gravitational lensing. The primary instrumental systematic for pair differencing CMB experiments is temperature-to-polarization leakage from mismatched co-located orthogonally polarized beams. We present extensive far field beam measurements taken in situ at the South Pole, and demonstrate how the resulting high-fidelity beam maps for each detector are used in dedicated simulations to predict the expected leakage in the final CMB maps, focusing on the 95, 150, and 220 GHz beams present in the BK15 dataset. We discuss prospects for dealing with temperature-to-polarization leakage in next-generation CMB experiments with hundreds of thousands of detectors, and how the beams systematics levels we achieve with current instrument and analysis technology will scale with detector count.

  2. KECK HIRES SPECTROSCOPY OF EXTRAGALACTIC H II REGIONS: C AND O ABUNDANCES FROM RECOMBINATION LINES

    SciTech Connect

    Esteban, Cesar; Mesa-Delgado, Adal; Bresolin, Fabio; Peimbert, Manuel; GarcIa-Rojas, Jorge; Peimbert, Antonio E-mail: amd@iac.es E-mail: peimbert@astroscu.unam.mx E-mail: peimbert@astroscu.unam.mx

    2009-07-20

    We present very deep spectrophotometry of 14 bright extragalactic H II regions belonging to spiral, irregular, and blue compact galaxies. The data for 13 objects were taken with the High Resolution Echelle Spectrometer on the Keck I telescope. We have measured C II recombination lines in 10 of the objects and O II recombination lines in eight of them. We have determined electron temperatures from line ratios of several ions, especially those of low ionization potential. We have found a rather tight linear empirical relation between T {sub e}([N II]) and T {sub e}([O III]). We have found that O II lines give always larger abundances than [O III] lines. Moreover, the difference of both O{sup ++} abundance determinations-the so-called abundance discrepancy factor-is very similar in all the objects, with a mean value of 0.26 {+-} 0.09 dex, independent of the properties of the H II region and of the parent galaxy. Using the observed recombination lines, we have determined the O, C, and C/O radial abundance gradients for three spiral galaxies: M33, M101, and NGC 2403, finding that C abundance gradients are always steeper than those of O, producing negative C/O gradients across the galactic disks. This result is similar to that found in the Milky Way and has important implications for chemical evolution models and the nucleosynthesis of C.

  3. KECK/HIRES SPECTROSCOPY OF V838 MONOCEROTIS IN OCTOBER 2005

    SciTech Connect

    Kaminski, T.; Schmidt, M.; Tylenda, R.; Konacki, M.; Gromadzki, M.

    2009-05-15

    V838 Monocerotis (V838 Mon) erupted at the beginning of 2002 becoming an extremely luminous star with L {approx_equal} 10{sup 6} L {sub sun}. Among various scenarios proposed to explain the nature of the outburst, the most promising is a stellar merger event. In this paper, we investigate the observational properties of the star and its surroundings in the post outburst phase. We have obtained a high-resolution optical spectrum of V838 Mon in 2005 October using the Keck I telescope. We have identified numerous atomic features and molecular bands present in the spectrum and provided an atlas of those features. In order to improve the spectrum interpretation, we have performed simple modeling of the molecular bands. Our analysis indicates that the spectrum is dominated by molecular absorption features arising in photospheric regions with temperatures of {approx}2400 K and in colder outer layers, where the temperature decreases to {approx}500 K. A number of resonance lines of neutral alkali metals are observed to show P Cygni profiles. Particularly interesting are numerous prominent emission lines of [Fe II]. All of them show practically the same profile, which can be well described by a Lorentzian profile. In the blue part of the spectrum, photospheric signatures of the B-type companion are easily seen. We have fitted the observed spectrum with a synthetic one and the obtained parameters are consistent with the B3V type. We have also estimated radial and rotational velocities of the companion.

  4. Status and new developments with the Keck I near-infrared tip-tilt sensor

    NASA Astrophysics Data System (ADS)

    Femenía Castellá, Bruno; Wizinowich, Peter; Rampy, Rachel; Cetre, Sylvain; Lilley, Scott; Lyke, Jim; Ragland, Sam; Stomski, Paul; van Dam, Marcos

    2016-07-01

    The sky coverage and performance of Laser Guide Star (LGS) adaptive optics (AO) systems is limited by the Natural Guide Star (NGS) used for low order correction (tip-tilt and defocus modes). This limitation can be reduced by measuring image motion of the NGS in the near-infrared where it is partially corrected by the LGS AO system and where stars are generally several magnitudes brighter than at visible wavelengths. We have integrated a Near-InfraRed Tip-Tilt Sensor (NIRTTS) with the Keck I telescopes LGS AO system. The sensor is a H2RG-based near-infrared camera with 0.05 arcsecond pixels. Low noise at high sample rates is achieved by only reading a small region of interest, from 2x2 to 16x16 pixels, centered on an NGS anywhere in an 100 arc second diameter field. The sensor operates at either Ks or H-band using light reflected by a choice of dichroic beam-splitters located in front of the OSIRIS integral field spectrograph. The implementation of the NIRTTS involved modifications to the AO bench, real-time control system, higher-level controls and operations software. NIRTTS is nearly ready for science operation in shared-risk mode. We are also implementing a number of enhancements to the NIRTTS system which involve substantial changes to the operations software. This work presents an update of the work performed since the NIRTTS system was reported in Ref. 1 and Ref. 2.

  5. A DEEP KECK/NIRC2 SEARCH FOR THERMAL EMISSION FROM PLANETARY COMPANIONS ORBITING FOMALHAUT

    SciTech Connect

    Currie, Thayne; Cloutier, Ryan; Debes, John H.; Kenyon, Scott J.; Kaisler, Denise

    2013-11-01

    We present deep Keck/NIRC2 1.6 and 3.8 μm imaging of Fomalhaut to constrain the near-infrared brightness of Fomalhaut b, recently confirmed as a likely planet, and search for additional planets at r {sub proj} = 15-150 AU. Using advanced/novel point spread function subtraction techniques, we identify seven candidate substellar companions Fomalhaut b-like projected separations. However, multi-epoch data show them to be background objects. We set a new 3σ upper limit for Fomalhaut b's H-band brightness of m(H) ∼23.15 or 1.5-4.5 M{sub J} . We do not recover the possible point source reported from Spitzer/IRAC data: at its location detection limits are similar to those for Fomalhaut b. Our data when combined with other recent work rule out planets with masses and projected separations comparable to HR 8799 bcde and M > 3 M{sub J} planets at r {sub proj} > 45 AU. The James Webb Space Telescope will likely be required to shed substantial further light on Fomalhaut's planetary system in the next decade.

  6. Characterization of the Inner Disk around HD 141569 A from Keck/NIRC2 L-Band Vortex Coronagraphy

    NASA Astrophysics Data System (ADS)

    Mawet, Dimitri; Choquet, Élodie; Absil, Olivier; Huby, Elsa; Bottom, Michael; Serabyn, Eugene; Femenia, Bruno; Lebreton, Jérémy; Matthews, Keith; Gomez Gonzalez, Carlos A.; Wertz, Olivier; Carlomagno, Brunella; Christiaens, Valentin; Defrère, Denis; Delacroix, Christian; Forsberg, Pontus; Habraken, Serge; Jolivet, Aissa; Karlsson, Mikael; Milli, Julien; Pinte, Christophe; Piron, Pierre; Reggiani, Maddalena; Surdej, Jean; Vargas Catalan, Ernesto

    2017-01-01

    HD 141569 A is a pre-main sequence B9.5 Ve star surrounded by a prominent and complex circumstellar disk, likely still in a transition stage from protoplanetary to debris disk phase. Here, we present a new image of the third inner disk component of HD 141569 A made in the L‧ band (3.8 μm) during the commissioning of the vector vortex coronagraph that has recently been installed in the near-infrared imager and spectrograph NIRC2 behind the W.M. Keck Observatory Keck II adaptive optics system. We used reference point-spread function subtraction, which reveals the innermost disk component from the inner working distance of ≃23 au and up to ≃70 au. The spatial scale of our detection roughly corresponds to the optical and near-infrared scattered light, thermal Q, N, and 8.6 μm PAH emission reported earlier. We also see an outward progression in dust location from the L‧ band to the H band (Very Large Telescope/SPHERE image) to the visible (Hubble Space Telescope (HST)/STIS image), which is likely indicative of dust blowout. The warm disk component is nested deep inside the two outer belts imaged by HST-NICMOS in 1999 (at 406 and 245 au, respectively). We fit our new L‧-band image and spectral energy distribution of HD 141569 A with the radiative transfer code MCFOST. Our best-fit models favor pure olivine grains and are consistent with the composition of the outer belts. While our image shows a putative very faint point-like clump or source embedded in the inner disk, we did not detect any true companion within the gap between the inner disk and the first outer ring, at a sensitivity of a few Jupiter masses.

  7. Telescopic hindsight

    NASA Astrophysics Data System (ADS)

    Cox, Laurence

    2014-08-01

    In reply to the physicsworld.com blog post "Cosmic blunders that have held back science" (2 June, http://ow.ly/xwC7C), about an essay by the astronomer Avi Loeb in which he criticized, among others, his Harvard University predecessor Edward Pickering, who claimed in 1909 that telescopes had reached their optimal size.

  8. Infrared telescope

    NASA Technical Reports Server (NTRS)

    Karr, G. R.; Hendricks, J. B.

    1985-01-01

    The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described.

  9. Keck Laser Illuminates AGN in the Distant Universe.

    NASA Astrophysics Data System (ADS)

    Melbourne, J.; Wright, S.; Le Mignant, D.; Barczys, M.; Larkin, J.; Max, C.; Koo, D.

    2004-12-01

    The Center for Adaptive Optics Treasury Survey (CATS) aims to combine deep HST images in the optical with deep Keck adaptive optics (AO) data in the near-infrared (NIR) to study distant galaxies, AGN, and supernovae. We recently achieved an important new milestone by securing the first high quality Keck laser guide star (LGS) AO image of faint galaxies. Six galaxies with redshifts ranging from 0.3-1.0 were targeted in one pointing in the GOODS-S field. Two are Chandra sources with complex morphologies suggestive of recent merger activity. Substructures seen in the NIR AO image, including the double nucleus of one Chandra source and multiple tight knots in another, are confirmed in the optical HST images (both about 0.1" FWHM) but are undetected in very deep, ground-based NIR images from ESO with seeing about 0.5" FWHM. We will present results on the stellar populations of the substructures as derived from photometry of the galaxy subcomponents using the NIR AO data and the optical HST data taken with four ACS filters.

  10. Keck Planet Imager and Characterizer: concept and phased implementation

    NASA Astrophysics Data System (ADS)

    Mawet, D.; Wizinowich, P.; Dekany, R.; Chun, M.; Hall, D.; Cetre, S.; Guyon, O.; Wallace, J. K.; Bowler, B.; Liu, M.; Ruane, G.; Serabyn, E.; Bartos, R.; Wang, J.; Vasisht, G.; Fitzgerald, M.; Skemer, A.; Ireland, M.; Fucik, J.; Fortney, J.; Crossfield, I.; Hu, R.; Benneke, B.

    2016-07-01

    The Keck Planet Imager and Characterizer (KPIC) is a cost-effective upgrade path to the W.M. Keck observatory (WMKO) adaptive optics (AO) system, building on the lessons learned from first and second-generation extreme AO (ExAO) coronagraphs. KPIC will explore new scientific niches in exoplanet science, while maturing critical technologies and systems for future ground-based (TMT, EELT, GMT) and space-based planet imagers (HabEx, LUVOIR). The advent of fast low-noise IR cameras (IR-APD, MKIDS, electron injectors), the rapid maturing of efficient wavefront sensing (WFS) techniques (Pyramid, Zernike), small inner working angle (IWA) coronagraphs (e.g., vortex) and associated low-order wavefront sensors (LOWFS), as well as recent breakthroughs in high contrast high resolution spectroscopy, open new direct exoplanet exploration avenues that are complementary to planet imagers such as VLT-SPHERE and the Gemini Planet Imager (GPI). For instance, the search and detailed characterization of planetary systems on solar-system scales around late-type stars, mostly beyond SPHERE and GPI's reaches, can be initiated now at WMKO.

  11. Selecting Your First Telescope.

    ERIC Educational Resources Information Center

    Harrington, Sherwood

    1982-01-01

    Designed for first-time telescope purchasers, provides information on how a telescope works; major telescope types (refractors, reflectors, compound telescopes); tripod, pier, altazimuth, and equatorial mounts; selecting a telescope; visiting an astronomy club; applications/limitations of telescope use; and tips on buying a telescope. Includes a…

  12. Estimation of Density of Localized States in Amorphous Se80Te20 and Se80Te10M10 (M = Cd, In, Sb) Alloys Using AC Conductivity Measurements

    NASA Astrophysics Data System (ADS)

    Chandel, N.; Mehta, N.; Kumar, A.

    2015-08-01

    The ac conductivity of amorphous Se80Te20 (a-Se80Te20) and amorphous Se80Te10M10 (a-Se80Te10M10) alloys has been measured as a function of temperature and frequency in a low-temperature regime. An analysis of the experimental data confirms that ac conductivity is reasonably well interpreted by the Austin-Mott model. The density of localized states was determined in the low-temperature region from 201 K to 280 K. Possible explanations of "metal-induced effects" on the conduction mechanism of a-Se80Te20 alloy are discussed.

  13. University of California ten meter telescope project

    NASA Astrophysics Data System (ADS)

    Nelson, J. E.

    1982-10-01

    A discussion is presented of the prospective design features of the segmented, 10-m diameter optical-IR range telescope which the University of California is planning to build on Mauna Kea, Hawaii, with attention to the performance levels obtained from prototypes. The telescope primary mirror will be formed by 36 actively controlled mirror segments, which will be polished to their desired shape by stressed mirror polishing. The active control system employs displacement sensors at the edges of the mirror segments to determine their positions, which are then adjusted by three displacement actuators/segment. The telescope overall design is described as a Ritchley-Cretien f/1.75-f/15 system. The telescope's dome is highly compact, and rotates on a stationary building in the manner of conventional telescope domes.

  14. Camera designs for the Keck Observatory LRIS and HIRES spectrometers

    NASA Astrophysics Data System (ADS)

    Epps, Harland W.

    1990-07-01

    The optical designs of three CCD cameras for the Keck Observatory spectrometers are described and illustrated with drawings and diagrams. The 8-element camera for the Low-Resolution Imaging Spectrometer (LRIS) has focal length 12.0 inches, entrance aperture 8.9 inches, and flat FOV diameter 2.93 inches; the camera is color corrected without refocusing over the spectral range 390-1000 nm. For the High-Resolution Echelle Spectrometer (HIRES), a larger and a smaller version of a 30-inch-focal-length camera have been designed. Each camera is color corrected at 310-1100 nm and comprises a single-element corrector, a concave mirror, a contact triplet field-flattening element, and a flat vacuum window. The smaller design, with 28.7-inch entrance aperture and flat FOV diameter 3.15 inches, has been selected for construction.

  15. The NASA Keck/HIRES Follow-Up Program

    NASA Astrophysics Data System (ADS)

    Endl, Michael

    2012-02-01

    We are currently in a ``golden age'' of characterizing exoplanets due to a rapidly growing sample of transiting planets. The most interesting systems are found by highly precise space photometry from missions like Kepler and CoRoT. We propose to continue and expand our program to use Keck/HIRES to confirm and characterize planet candidates from the CoRoT mission. Our two major science goals are: 1. to determine the mass, and thus mean density, of the planet via precise radial velocity measurements and 2. to obtain high signal-to-noise, high resolution spectra of the host stars to determine accurate stellar parameters. Our program has significantly contributed to the discovery of 8 new transiting systems announced by CoRoT in 2010 & 2011. Over the next year we suggest to focus on planet candidates in the Neptune and Super-Earth range.

  16. The NASA Keck/HIRES Follow-Up Program

    NASA Astrophysics Data System (ADS)

    Endl, Michael

    2012-08-01

    We are currently in a ``golden age'' of characterizing exoplanets due to a rapidly growing sample of transiting planets. The most interesting systems are found by highly precise space photometry from missions like Kepler and CoRoT. We propose to continue and expand our program to use Keck/HIRES to confirm and characterize planet candidates from the CoRoT mission. Our two major science goals are: 1. to determine the mass, and thus mean density, of the planet via precise radial velocity measurements and 2. to obtain high signal-to-noise, high resolution spectra of the host stars to determine accurate stellar parameters. Our program has significantly contributed to the discovery of 8 new transiting systems announced by CoRoT in 2010 & 2011. Over the next year we suggest to focus on planet candidates in the Neptune and Super-Earth range.

  17. Joint Analysis of BICEP2/Keck Array and Planck Data

    NASA Astrophysics Data System (ADS)

    BICEP2/Keck and Planck Collaborations; Ade, P. A. R.; Aghanim, N.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Arnaud, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barkats, D.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Benton, S. J.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bischoff, C. A.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Brevik, J. A.; Bucher, M.; Buder, I.; Bullock, E.; Burigana, C.; Butler, R. C.; Buza, V.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Colombo, L. P. L.; Combet, C.; Connors, J.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; De Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dowell, C. D.; Duband, L.; Ducout, A.; Dunkley, J.; Dupac, X.; Dvorkin, C.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Filippini, J. P.; Finelli, F.; Fliescher, S.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Gjerløw, E.; Golwala, S. R.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Halpern, M.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Hasselfield, M.; Helou, G.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hilton, G. C.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Hristov, V. V.; Huffenberger, K. M.; Hui, H.; Hurier, G.; Irwin, K. D.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Karakci, A.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Keihänen, E.; Kernasovskiy, S. A.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kovac, J. M.; Krachmalnicoff, N.; Kunz, M.; Kuo, C. L.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leitch, E. M.; Leonardi, R.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Lueker, M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Mason, P.; Matarrese, S.; Megerian, K. G.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nguyen, H. T.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Brient, R.; Ogburn, R. W.; Orlando, A.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Piat, M.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Pratt, G. W.; Prunet, S.; Pryke, C.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Richter, S.; Ristorcelli, I.; Rocha, G.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Schwarz, R.; Scott, D.; Seiffert, M. D.; Sheehy, C. D.; Spencer, L. D.; Staniszewski, Z. K.; Stolyarov, V.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Teply, G. P.; Terenzi, L.; Thompson, K. L.; Toffolatti, L.; Tolan, J. E.; Tomasi, M.; Tristram, M.; Tucci, M.; Turner, A. D.; Valenziano, L.; Valiviita, J.; van Tent, B.; Vibert, L.; Vielva, P.; Vieregg, A. G.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Weber, A. C.; Wehus, I. K.; White, M.; White, S. D. M.; Willmert, J.; Wong, C. L.; Yoon, K. W.; Yvon, D.; Zacchei, A.; Zonca, A.; Bicep2/Keck; Planck Collaborations

    2015-03-01

    We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg2 patch of sky centered on RA 0 h, Dec. -57.5 ° . The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μ K deg in Q and U at 143 GHz). We detect 150 ×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-Λ CDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r0.05<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0 σ significance.

  18. Joint analysis of BICEP2/keck array and Planck Data.

    PubMed

    Ade, P A R; Aghanim, N; Ahmed, Z; Aikin, R W; Alexander, K D; Arnaud, M; Aumont, J; Baccigalupi, C; Banday, A J; Barkats, D; Barreiro, R B; Bartlett, J G; Bartolo, N; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Benton, S J; Bernard, J-P; Bersanelli, M; Bielewicz, P; Bischoff, C A; Bock, J J; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Brevik, J A; Bucher, M; Buder, I; Bullock, E; Burigana, C; Butler, R C; Buza, V; Calabrese, E; Cardoso, J-F; Catalano, A; Challinor, A; Chary, R-R; Chiang, H C; Christensen, P R; Colombo, L P L; Combet, C; Connors, J; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J-M; Désert, F-X; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dowell, C D; Duband, L; Ducout, A; Dunkley, J; Dupac, X; Dvorkin, C; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Filippini, J P; Finelli, F; Fliescher, S; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Frejsel, A; Galeotta, S; Galli, S; Ganga, K; Ghosh, T; Giard, M; Gjerløw, E; Golwala, S R; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Halpern, M; Hansen, F K; Hanson, D; Harrison, D L; Hasselfield, M; Helou, G; Henrot-Versillé, S; Herranz, D; Hildebrandt, S R; Hilton, G C; Hivon, E; Hobson, M; Holmes, W A; Hovest, W; Hristov, V V; Huffenberger, K M; Hui, H; Hurier, G; Irwin, K D; Jaffe, A H; Jaffe, T R; Jewell, J; Jones, W C; Juvela, M; Karakci, A; Karkare, K S; Kaufman, J P; Keating, B G; Kefeli, S; Keihänen, E; Kernasovskiy, S A; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Kovac, J M; Krachmalnicoff, N; Kunz, M; Kuo, C L; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J-M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leitch, E M; Leonardi, R; Levrier, F; Lewis, A; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Lueker, M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Mangilli, A; Maris, M; Martin, P G; Martínez-González, E; Masi, S; Mason, P; Matarrese, S; Megerian, K G; Meinhold, P R; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M-A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Moss, A; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nguyen, H T; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; O'Brient, R; Ogburn, R W; Orlando, A; Pagano, L; Pajot, F; Paladini, R; Paoletti, D; Partridge, B; Pasian, F; Patanchon, G; Pearson, T J; Perdereau, O; Perotto, L; Pettorino, V; Piacentini, F; Piat, M; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Pratt, G W; Prunet, S; Pryke, C; Puget, J-L; Rachen, J P; Reach, W T; Rebolo, R; Reinecke, M; Remazeilles, M; Renault, C; Renzi, A; Richter, S; Ristorcelli, I; Rocha, G; Rossetti, M; Roudier, G; Rowan-Robinson, M; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savelainen, M; Savini, G; Schwarz, R; Scott, D; Seiffert, M D; Sheehy, C D; Spencer, L D; Staniszewski, Z K; Stolyarov, V; Sudiwala, R; Sunyaev, R; Sutton, D; Suur-Uski, A-S; Sygnet, J-F; Tauber, J A; Teply, G P; Terenzi, L; Thompson, K L; Toffolatti, L; Tolan, J E; Tomasi, M; Tristram, M; Tucci, M; Turner, A D; Valenziano, L; Valiviita, J; Van Tent, B; Vibert, L; Vielva, P; Vieregg, A G; Villa, F; Wade, L A; Wandelt, B D; Watson, R; Weber, A C; Wehus, I K; White, M; White, S D M; Willmert, J; Wong, C L; Yoon, K W; Yvon, D; Zacchei, A; Zonca, A

    2015-03-13

    We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400  deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2  μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150  GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r_{0.05}<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.

  19. Strehl ratio and modulation transfer function for segmented mirror telescopes as functions of segment phase error.

    PubMed

    Chanan, G; Troy, M

    1999-11-01

    We derive the Strehl ratio for a segmented mirror telescope as a function of the rms segment phase error and the observing wavelength, with and without the effects of the atmosphere. A simple analytical expression is given for the atmosphere-free case. Although our specific results are in the context of the Keck telescope, they are presented in a way that should be readily adaptable to other segmented geometries. We also derive the corresponding modulation transfer functions. These results are useful in determining how accurately a segmented mirror telescope needs to be phased for a variety of observing applications.

  20. Shape model of asteroid (130) Elektra from optical photometry and disk-resolved images from VLT/SPHERE and Nirc2/Keck

    NASA Astrophysics Data System (ADS)

    Hanuš, J.; Marchis, F.; Viikinkoski, M.; Yang, B.; Kaasalainen, M.

    2017-02-01

    Context. Asteroid (130) Elektra belongs to one of the six known triple asteroids in the main belt, so its mass has been reliably determined. Aims: We aim to use all available disk-resolved images of (130) Elektra obtained by the SPHERE instrument at VLT and by the Nirc2 of the Keck telescope together with the disk-integrated photometry to determine its shape model and its size. The volume can be then used in combination with the known mass to derive the bulk density of the primary. Methods: We have applied the All-Data Asteroid Modeling (ADAM) algorithm to the optical disk-integrated data, two disk-resolved images obtained by the SPHERE instrument, and 13 disk-resolved images from the Nirc2 of the Keck telescope. We have also derived the shape model and size of Elektra. Results: We present the shape model, volume-equivalent diameter (199 ± 7 km) and bulk density (1.60 ± 0.13 g cm-3) of the C-type asteroid Elektra.

  1. Circumnuclear Star Clusters in the Galaxy Merger NGC 6240, Observed with Keck Adaptive Optics and HST

    SciTech Connect

    Pollack, L K; Max, C E; Schneider, G

    2007-02-12

    We discuss images of the central {approx} 10 kpc (in projection) of the galaxy merger NGC 6240 at H and K{prime} bands, taken with the NIRC2 narrow camera on Keck II using natural guide star adaptive optics. We detect 28 star clusters in the NIRC2 images, of which only 7 can be seen in the similar-spatial-resolution, archival WFPC2 Planetary Camera data at either B or I bands. Combining the NIRC2 narrow camera pointings with wider NICMOS NIC2 images taken with the F110W, F160W, and F222M filters, we identify a total of 32 clusters that are detected in at least one of these 5 infrared ({lambda}{sub c} > 1 {micro}m) bandpasses. By comparing to instantaneous burst, stellar population synthesis models (Bruzual & Charlot 2003), we estimate that most of the clusters are consistent with being {approx} 15 Myr old and have photometric masses ranging from 7 x 10{sup 5} M{sub {circle_dot}} to 4 x 10{sup 7}M{sub {circle_dot}}. The total contribution to the star formation rate (SFR) from these clusters is approximately 10M{sub {circle_dot}} yr{sup -1}, or {approx} 10% of the total SFR in the nuclear region. We use these newly discovered clusters to estimate the extinction toward NGC 6240's double nuclei, and find values of A{sub v} as high as 14 magnitudes along some sightlines, with an average extinction of A{sub v} {approx} 7 mag toward sightlines within {approx} 3-inches of the double nuclei.

  2. Robotic Telescopes

    NASA Astrophysics Data System (ADS)

    Akerlof, C. W.

    2001-05-01

    Since the discovery of gamma-ray bursts, a number of groups have attempted to detect correlated optical transients from these elusive objects. Following the flight of the BATSE instrument on the Compton Gamma-Ray Observatory in 1991, a prompt burst coordinate alert service, BACODINE (now GCN) became available to ground-based telescopes. Several instruments were built to take advantage of this facility, culminating in the discovery of a bright optical flash associated with GRB990123. To date, that single observation remains unique - no other prompt flashes have been seen for a dozen or so other bursts observed with comparably short response times. Thus, GRB prompt optical luminosities may be considerably dimmer than observed for the GRB990123 event or even absent altogether. A new generation of instruments is prepared to explore these possibilties using burst coordinates provided by HETE-2, Swift, Ballerina, Agile and other satellite missions. These telescopes have response times as short as a few seconds and reach limiting magnitudes, m_v 20, guaranteeing a sensitivity sufficient to detect the afterglow many hours later. Results from these experiments should provide important new data about the dynamics and locale of GRBs.

  3. MID-INFRARED SIZE SURVEY OF YOUNG STELLAR OBJECTS: DESCRIPTION OF KECK SEGMENT-TILTING EXPERIMENT AND BASIC RESULTS

    SciTech Connect

    Monnier, J. D.; Tannirkulam, A.; Tuthill, P. G.; Ireland, M.; Cohen, R.; Perrin, M. D.

    2009-07-20

    The mid-infrared properties of pre-planetary disks are sensitive to the temperature and flaring profiles of disks for the regions where planet formation is expected to occur. In order to constrain theories of planet formation, we have carried out a mid-infrared ({lambda} = 10.7 {mu}m) size survey of young stellar objects using the segmented Keck telescope in a novel configuration. We introduced a customized pattern of tilts to individual mirror segments to allow efficient sparse-aperture interferometry, allowing full aperture synthesis imaging with higher calibration precision than traditional imaging. In contrast to previous surveys on smaller telescopes and with poorer calibration precision, we find that most objects in our sample are partially resolved. Here, we present the main observational results of our survey of five embedded massive protostars, 25 Herbig Ae/Be stars, 3 T Tauri stars, 1 FU Ori system, and five emission-line objects of uncertain classification. The observed mid-infrared sizes do not obey the size-luminosity relation found at near-infrared wavelengths and a companion paper will provide further modeling analysis of this sample. In addition, we report imaging results for a few of the most resolved objects, including complex emission around embedded massive protostars, the photoevaporating circumbinary disk around MWC 361A, and the subarcsecond binaries T Tau, FU Ori, and MWC 1080.

  4. A case study in adaptable and reusable infrastructure at the Keck Observatory Archive: VO interfaces, moving targets, and more

    NASA Astrophysics Data System (ADS)

    Berriman, G. Bruce; Cohen, Richard W.; Colson, Andrew; Gelino, Christopher R.; Good, John C.; Kong, Mihseh; Laity, Anastasia C.; Mader, Jeffrey A.; Swain, Melanie A.; Tran, Hien D.; Wang, Shin-Ywan

    2016-08-01

    The Keck Observatory Archive (KOA) (https://koa.ipac.caltech.edu) curates all observations acquired at the W. M. Keck Observatory (WMKO) since it began operations in 1994, including data from eight active instruments and two decommissioned instruments. The archive is a collaboration between WMKO and the NASA Exoplanet Science Institute (NExScI). Since its inception in 2004, the science information system used at KOA has adopted an architectural approach that emphasizes software re-use and adaptability. This paper describes how KOA is currently leveraging and extending open source software components to develop new services and to support delivery of a complete set of instrument metadata, which will enable more sophisticated and extensive queries than currently possible. In August 2015, KOA deployed a program interface to discover public data from all instruments equipped with an imaging mode. The interface complies with version 2 of the Simple Imaging Access Protocol (SIAP), under development by the International Virtual Observatory Alliance (IVOA), which defines a standard mechanism for discovering images through spatial queries. The heart of the KOA service is an R-tree-based, database-indexing mechanism prototyped by the Virtual Astronomical Observatory (VAO) and further developed by the Montage Image Mosaic project, designed to provide fast access to large imaging data sets as a first step in creating wide-area image mosaics (such as mosaics of subsets of the 4.7 million images of the SDSS DR9 release). The KOA service uses the results of the spatial R-tree search to create an SQLite data database for further relational filtering. The service uses a JSON configuration file to describe the association between instrument parameters and the service query parameters, and to make it applicable beyond the Keck instruments. The images generated at the Keck telescope usually do not encode the image footprints as WCS fields in the FITS file headers. Because SIAP

  5. Models of the η Corvi Debris Disk from the Keck Interferometer, Spitzer, and Herschel

    NASA Astrophysics Data System (ADS)

    Lebreton, J.; Beichman, C.; Bryden, G.; Defrère, D.; Mennesson, B.; Millan-Gabet, R.; Boccaletti, A.

    2016-02-01

    Debris disks are signposts of analogs to small-body populations of the solar system, often, however, with much higher masses and dust production rates. The disk associated with the nearby star η Crv is especially striking, as it shows strong mid- and far-infrared excesses despite an age of ∼1.4 Gyr. We undertake constructing a consistent model of the system that can explain a diverse collection of spatial and spectral data. We analyze Keck Interferometer Nuller measurements and revisit Spitzer and additional spectrophotometric data, as well as resolved Herschel images, to determine the dust spatial distribution in the inner exozodi and in the outer belt. We model in detail the two-component disk and the dust properties from the sub-AU scale to the outermost regions by fitting simultaneously all measurements against a large parameter space. The properties of the cold belt are consistent with a collisional cascade in a reservoir of ice-free planetesimals at 133 AU. It shows marginal evidence for asymmetries along the major axis. KIN enables us to establish that the warm dust consists of a ring that peaks between 0.2 and 0.8 AU. To reconcile this location with the ∼400 K dust temperature, very high albedo dust must be invoked, and a distribution of forsterite grains starting from micron sizes satisfies this criterion, while providing an excellent fit to the spectrum. We discuss additional constraints from the LBTI and near-infrared spectra, and we present predictions of what James Webb Space Telescope can unveil about this unusual object and whether it can detect unseen planets.

  6. MODELS OF THE η CORVI DEBRIS DISK FROM THE KECK INTERFEROMETER, SPITZER, AND HERSCHEL

    SciTech Connect

    Lebreton, J.; Beichman, C.; Millan-Gabet, R.; Bryden, G.; Mennesson, B.; Defrère, D.; Boccaletti, A.

    2016-02-01

    Debris disks are signposts of analogs to small-body populations of the solar system, often, however, with much higher masses and dust production rates. The disk associated with the nearby star η Crv is especially striking, as it shows strong mid- and far-infrared excesses despite an age of ∼1.4 Gyr. We undertake constructing a consistent model of the system that can explain a diverse collection of spatial and spectral data. We analyze Keck Interferometer Nuller measurements and revisit Spitzer and additional spectrophotometric data, as well as resolved Herschel images, to determine the dust spatial distribution in the inner exozodi and in the outer belt. We model in detail the two-component disk and the dust properties from the sub-AU scale to the outermost regions by fitting simultaneously all measurements against a large parameter space. The properties of the cold belt are consistent with a collisional cascade in a reservoir of ice-free planetesimals at 133 AU. It shows marginal evidence for asymmetries along the major axis. KIN enables us to establish that the warm dust consists of a ring that peaks between 0.2 and 0.8 AU. To reconcile this location with the ∼400 K dust temperature, very high albedo dust must be invoked, and a distribution of forsterite grains starting from micron sizes satisfies this criterion, while providing an excellent fit to the spectrum. We discuss additional constraints from the LBTI and near-infrared spectra, and we present predictions of what James Webb Space Telescope can unveil about this unusual object and whether it can detect unseen planets.

  7. KECK/LRIS SPECTROSCOPIC CONFIRMATION OF COMA CLUSTER DWARF GALAXY MEMBERSHIP ASSIGNMENTS

    SciTech Connect

    Chiboucas, Kristin; Tully, R. Brent; Marzke, Ronald O.; Trentham, Neil; Ferguson, Henry C.; Hammer, Derek; Carter, David; Khosroshahi, Habib E-mail: tully@ifa.hawaii.ed E-mail: trentham@ast.cam.ac.u E-mail: hammerd@pha.jhu.ed E-mail: habib@ipm.i

    2010-11-01

    Keck/LRIS multi-object spectroscopy has been carried out on 140 of some of the lowest and highest surface brightness faint (19 < R < 22) dwarf galaxy candidates in the core region of the Coma Cluster. These spectra are used to measure redshifts and establish membership for these faint dwarf populations. The primary goal of the low surface brightness sample is to test our ability to use morphological and surface brightness criteria to distinguish between Coma Cluster members and background galaxies using high resolution Hubble Space Telescope/Advanced Camera for Surveys images. Candidates were rated as expected members, uncertain, or expected background. From 93 spectra, 51 dwarf galaxy members and 20 background galaxies are identified. Our morphological membership estimation success rate is {approx}100% for objects expected to be members and better than {approx}90% for galaxies expected to be in the background. We confirm that low surface brightness is a very good indicator of cluster membership. High surface brightness galaxies are almost always background with confusion arising only from the cases of the rare compact elliptical (cE) galaxies. The more problematic cases occur at intermediate surface brightness. Many of these galaxies are given uncertain membership ratings, and these were found to be members about half of the time. Including color information will improve membership determination but will fail for some of the same objects that are already misidentified when using only surface brightness and morphology criteria. cE galaxies with B-V colors {approx}0.2 mag redward of the red sequence in particular require spectroscopic follow up. In a sample of 47 high surface brightness, ultracompact dwarf candidates, 19 objects have redshifts which place them in the Coma Cluster, while another 6 have questionable redshift measurements but may also prove to be members. Redshift measurements are presented and the use of indirect means for establishing cluster

  8. The QACITS pointing sensor: from theory to on-sky operation on Keck/NIRC2

    NASA Astrophysics Data System (ADS)

    Huby, Elsa; Absil, Olivier; Mawet, Dimitri; Baudoz, Pierre; Femenıa Castellã, Bruno; Bottom, Michael; Ngo, Henry; Serabyn, Eugene

    2016-07-01

    Small inner working angle coronagraphs are essential to benefit from the full potential of large and future extremely large ground-based telescopes, especially in the context of the detection and characterization of exoplanets. Among existing solutions, the vortex coronagraph stands as one of the most effective and promising solutions. However, for focal-plane coronagraph, a small inner working angle comes necessarily at the cost of a high sensitivity to pointing errors. This is the reason why a pointing control system is imperative to stabilize the star on the vortex center against pointing drifts due to mechanical flexures, that generally occur during observation due for instance to temperature and/or gravity variations. We have therefore developed a technique called QACITS1 (Quadrant Analysis of Coronagraphic Images for Tip-tilt Sensing), which is based on the analysis of the coronagraphic image shape to infer the amount of pointing error. It has been shown that the flux gradient in the image is directly related to the amount of tip-tilt affecting the beam. The main advantage of this technique is that it does not require any additional setup and can thus be easily implemented on all current facilities equipped with a vortex phase mask. In this paper, we focus on the implementation of the QACITS sensor at Keck/NIRC2, where an L-band AGPM has been recently commissioned (June and October 2015), successfully validating the QACITS estimator in the case of a centrally obstructed pupil. The algorithm has been designed to be easily handled by any user observing in vortex mode, which is available for science in shared risk mode since 2016B.

  9. KECK OBSERVATIONS OF THE GALACTIC CENTER SOURCE G2: GAS CLOUD OR STAR?

    SciTech Connect

    Phifer, K.; Meyer, L.; Ghez, A. M.; Witzel, G.; Yelda, S.; Boehle, A.; Morris, M. R.; Becklin, E. E.; Do, T.; Lu, J. R.; Matthews, K.

    2013-08-10

    We present new observations and analysis of G2-the intriguing red emission-line object which is quickly approaching the Galaxy's central black hole. The observations were obtained with the laser guide star adaptive optics systems on the W. M. Keck I and II telescopes (2006-2012) and include spectroscopy (R {approx} 3600) centered on the hydrogen Br{gamma} line as well as K' (2.1 {mu}m) and L' (3.8 {mu}m) imaging. Analysis of these observations shows the Br{gamma} line emission has a positional offset from the L' continuum. This offset is likely due to background source confusion at L'. We therefore present the first orbital solution derived from Br{gamma} line astrometry, which, when coupled with radial velocity measurements, results in a later time of closest approach (2014.21 {+-} 0.14), closer periastron (130 AU, 1600 R{sub s}), and higher eccentricity (0.9814 {+-} 0.0060) compared to a solution using L' astrometry. It is shown that G2 has no K' counterpart down to K' {approx} 20 mag. G2's L' continuum and the Br{gamma} line emission appears unresolved in almost all epochs, which implies that the bulk of the emission resides in a compact region. The observations altogether suggest that while G2 has a gaseous component that is tidally interacting with the central black hole, there is likely a central star providing the self-gravity necessary to sustain the compact nature of this object.

  10. Holographic telescope

    NASA Astrophysics Data System (ADS)

    Odhner, Jefferson E.

    2016-07-01

    Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases replace conventional optical elements that work on the principal of refraction. An HOE can be thinner, lighter, can have more functionality, and can be lower cost than conventional optics. An HOE can serve as a beam splitter, spectral filter, mirror, and lens all at the same time. For a single wavelength system, an HOE can be an ideal solution but they have not been widely accepted for multispectral systems because they suffer from severe chromatic aberration. A refractive optical system also suffers from chromatic aberration but it is generally not as severe. To color correct a conventional refractive optical system, a flint glass and a crown glass are placed together such that the color dispersion of the flint and the crown cancel each other out making an achromatic lens (achromat) and the wavelengths all focus to the same point. The color dispersion of refractive lenses and holographic lenses are opposite from each other. In a diffractive optical system, long wavelengths focus closer (remember for HOEs: RBM "red bends more") than nominal focus while shorter wavelengths focus further out. In a refractive optical system, it is just the opposite. For this reason, diffractives can be incorporated into a refractive system to do the color correction and often cut down on the number of optical elements used [1.]. Color correction can also be achieved with an all-diffractive system by combining a holographic optical element with its conjugate. In this way the color dispersion of the first holographic optical element can be cancelled by the color dispersion of the second holographic optic. It is this technique that will be exploited in this paper to design a telescope made entirely of holographic optical elements. This telescope could be more portable (for field operations) the same technique could be used to make optics light enough for incorporation into a UAV.

  11. Monitoring Io volcanism with AO telescopes during and after the NH flyby

    NASA Astrophysics Data System (ADS)

    Marchis, F.; Spencer, J. R.; Lopes, R. M.; Davies, A. G.; Dumas, C.

    2007-12-01

    To support the New Horizons (NH) Jupiter encounter we monitored Io's volcanic activity using high angular resolution images in the near infrared (1-5 microns) provided by adaptive optics (AO) systems available on 8-10m class telescopes. We initiated the campaign on Feb. 25 2007 with data obtained with the VLT-Yepun telescope (ESO, Paranal, Chile), just before NH closest approach. We continued monitoring with the Gemini North telescope (Hawaii, USA). The last observation was taken on May 28 2007. Numerous active volcanoes are visible in the data but the Tvashtar eruption is by far the most energetic. Extremely high angular resolution data from NH revealed fine detail of the eruption, such as the presence of an active plume [1]. This volcano has an interesting past history. It was seen as a powerful eruption from Nov. 26 1999 during the Galileo I25 [2] flyby to Feb. 19 2001 from the ground [3]. It was dormant or below our ground-based limit of detection (T<330 K assuming an area of 460 km2) between Dec 2001 and May 2004 [4,5]. The re-awakening of the volcano was reported by Laver et al. [6] in April 2006 based on Keck Adaptive Optics (AO) observations. Our last Gemini AO observation taken on May 26 shows that Tvashtar was still very active. Based on the previous behavior of this volcano [7] it is very likely that the activity reported in 2007 is a continuation of the Tvashtar-2006 eruption. Other hot spots, such as Loki Patera, Pele, and a new hot spot located north of Loki Patera, were seen in our data. We will describe the global picture of Io's volcanic activity derived from our observations, comparing it with previous observations from the Galileo spacecraft and using ground-based AO. 1. Spencer et al., AGU, this session, 2007 2. McEwen et al., Science, 288, 1193-1198, 2000 3. Marchis et al. Icarus, 160, 124-131, 2002 4. Marchis et al., Icarus, 176, 1, 2005 5. Marchis et al., AGU Fall meeting, V33C-1483, 2004 6. Laver et al., Icarus, in press, 2006 7. Milazzo et

  12. Illuminating Free-floating Planet Demographics with Keck AO

    NASA Astrophysics Data System (ADS)

    Henderson, Calen B.

    2017-01-01

    The frequency and mass function of free-floating planets (FFPs) are unknown. Gravitational microlensing is able to explore the demographics of FFPs, which are identifiable as short-timescale microlensing events, lasting of-order 1 day for Jupiter-mass planets. In 2011, the MOA ground-based microlensing survey group announced the discovery of an excess of short-timescale microlensing events over what was expected from Galactic models that incorporate stellar densities and kinematics. They account for this excess by positing a population of Jupiter-mass FFPs that outnumbers stars by a ratio of nearly 2:1. However, there are several other possible astrophysical explanations for short-timescale microlensing events, including bound planets on wide orbits and high-velocity stars. Although the specific events identified by MOA lack mass measurements, high-resolution imaging can determine whether the lens systems are luminous, which would exclude the FFP conclusion through proof by contradiction. We have taken H-band adaptive optics (AO) observations of the MOA FFP candidates using NIRC2 on Keck II in order to test this result. Here I will present preliminary results from these AO observations, which will help inform our understanding of the demographics of FFPs.

  13. The Keck Aperture Masking Experiment: Dust Enshrouded Red Giants

    NASA Technical Reports Server (NTRS)

    Blasius, T. D.; Monnier, J. D.; Tuthill, P. G.; Danchi, W. C.; Anderson, M.

    2012-01-01

    While the importance of dusty asymptotic giant branch (AGB) stars to galactic chemical enrichment is widely recognised, a sophisticated understanding of the dust formation and wind-driving mechanisms has proven elusive due in part to the difficulty in spatially-resolving the dust formation regions themselves. We have observed twenty dust-enshrouded AGB stars as part of the Keck Aperture Masking Experiment, resolving all of them in multiple near-infrared bands between 1.5 m and 3.1 m. We find 45% of the targets to show measurable elongations that, when correcting for the greater distances of the targets, would correspond to significantly asymmetric dust shells on par with the well-known cases of IRC +10216 or CIT 6. Using radiative transfer models, we find the sublimation temperature of Tsub(silicates) = 1130 90K and Tsub(amorphous carbon) = 1170 60 K, both somewhat lower than expected from laboratory measurements and vastly below temperatures inferred from the inner edge of YSO disks. The fact that O-rich and C-rich dust types showed the same sublimation temperature was surprising as well. For the most optically-thick shells ( 2.2 m > 2), the temperature profile of the inner dust shell is observed to change substantially, an effect we suggest could arise when individual dust clumps become optically-thick at the highest mass-loss rates.

  14. Keck Spectroscopy of NGVS Sources: Milky Way Halo Star Kinematics

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Guhathakurta, Puragra; Peng, Eric W.; Toloba, Elisa; Next Generation Virgo Cluster Survey (NGVS) Collaboration

    2017-01-01

    We present a study of the kinematics of main sequence turnoff stars in the halo of the Milky Way based on Next Generation Virgo Cluster Survey photometry and Keck/DEIMOS spectroscopic follow-up. Specifically, we investigate the properties of the Virgo overdensity and Sagittarius stream Milky Way halo substructures in the foreground of the Virgo Cluster of galaxies. We use an inverse concentration (iC) parameter that characterizes the angular size of a source, which is defined by the magnitude difference measured by two different apertures for the same object. After combining this information as well as redshift measured from spectra into a Z vs iC plot, all of the objects are separated clearly into three categories: foreground Milky Way stars, Virgo globular clusters, and background galaxies. Most objects located in unexpected regions in the V_iC plot are subsequently rejected through a rigorous examination due to low spectral quality or bad imaging quality, indicating that our sample selection approach gives a very clean classification. We then select Sagittarius stream stars and Virgo overdensity stars out of the foreground star sample to characterize their distributions of spatial position, radial velocity and metallicity, from which we can probe deeper into the history of structure formation in the Milky Way Galaxy. This research was supported by NASA and the National Science Foundation. HZ has been sponsored by China Scholarship Council to carry out this research project at University of California, Santa Cruz.

  15. Shack-Hartmann Phasing of Segmented Telescopes: Systematic Effects from Lenslet Arrays

    NASA Technical Reports Server (NTRS)

    Troy, Mitchell; Chanan, Gary; Roberts, Jennifer

    2010-01-01

    The segments in the Keck telescopes are routinely phased using a Shack-Hartmann wavefront sensor with sub-apertures that span adjacent segments. However, one potential limitation to the absolute accuracy of this technique is that it relies on a lenslet array (or a single lens plus a prism array) to form the subimages. These optics have the potential to introduce wavefront errors and stray reflections at the subaperture level that will bias the phasing measurement. We present laboratory data to quantify this effect, using measured errors from Keck and two other lenslet arrays. In addition, as part of the design of the Thirty Meter Telescope Alignment and Phasing System we present a preliminary investigation of a lenslet-free approach that relies on Fresnel diffraction to form the subimages at the CCD. Such a technique has several advantages, including the elimination of lenslet aberrations.

  16. The scaling relationship between telescope cost and aperture size for very large telescopes

    NASA Technical Reports Server (NTRS)

    van Belle, Gerard T.; Meinel, Aden Baker; Meinel, Marjorie Pettit

    2004-01-01

    Cost data for ground-based telescopes of the last century are analyzed for trends in the relationship between aperture size and cost. We find that for apertures built prior to 1980, costs scaled as aperture size to the 2.8 power, which is consistent with the precious finding of Meinel (1978). After 1980, 'traditional' monolithic mirror telescope costs have scaled as aperture to the 2.5 power. The large multiple mirror telescopes built or in construction during this time period (Keck, LBT, GTC) appear to deviate from this relationship with significant cost savings as a result, although it is unclear what power law such structures follow. We discuss the implications of the current cost-aperture size data on the proposed large telescope projects of the next ten to twenty years. Structures that naturally tend towards the 2.0 power in the cost-aperture relationship will be the favorable choice for future extremely large apertures; out expectation is that space-based structures will ultimately gain economic advantage over ground-based ones.

  17. BICEP2/Keck Array. VII. Matrix Based E/B Separation Applied to Bicep2 and the Keck Array

    NASA Astrophysics Data System (ADS)

    BICEP2 Collaboration; Keck Array Collaboration; Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bowens-Rubin, R.; Brevik, J. A.; Buder, I.; Bullock, E.; Buza, V.; Connors, J.; Crill, B. P.; Duband, L.; Dvorkin, C.; Filippini, J. P.; Fliescher, S.; Grayson, J.; Halpern, M.; Harrison, S.; Hildebrandt, S. R.; Hilton, G. C.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Namikawa, T.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Steinbach, B.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Tucker, C.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wiebe, D. V.; Willmert, J.; Wong, C. L.; Wu, W. L. K.; Yoon, K. W.

    2016-07-01

    A linear polarization field on the sphere can be uniquely decomposed into an E-mode and a B-mode component. These two components are analytically defined in terms of spin-2 spherical harmonics. Maps that contain filtered modes on a partial sky can also be decomposed into E-mode and B-mode components. However, the lack of full sky information prevents orthogonally separating these components using spherical harmonics. In this paper, we present a technique for decomposing an incomplete map into E and B-mode components using E and B eigenmodes of the pixel covariance in the observed map. This method is found to orthogonally define E and B in the presence of both partial sky coverage and spatial filtering. This method has been applied to the Bicep2 and the Keck Array maps and results in reducing E to B leakage from ΛCDM E-modes to a level corresponding to a tensor-to-scalar ratio of r\\lt 1× {10}-4.

  18. Detectors for the South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Chang, C. L.; Ade, P.; Aird, K.; Austermann, J.; Beall, J.; Becker, D.; Benson, B.; Bleem, L.; Britton, J.; Carlstrom, J.; Cho, H.; de Haan, T.; Crawford, T.; Crites, A.; Datesman, A.; Dobbs, M.; Everett, W.; Ewall-Wice, A.; George, E.; Halverson, N.; Harrington, N.; Henning, J.; Hilton, G.; Holzapfel, W.; Hoover, S.; Hubmayr, J.; Irwin, K.; Keisler, R.; Kennedy, J.; Lee, A.; Leitch, E.; Li, D.; Lueker, M.; Marrone, D. P.; Mcmahon, J.; Mehl, J.; Meyer, S.; Montgomery, J.; Montroy, T.; Natoli, T.; Nibarger, J.; Niemack, M.; Novosad, V.; Padin, S.; Plagge, T.; Pryke, C.; Reichardt, C.; Ruhl, J.; Saliwanchik, B.; Sayre, J.; Schafer, K.; Shirokoff, E.; Story, K.; Vanderlinde, K.; Vieira, J.; Wang, G.; Williamson, R.; Yefremenko, V.; Yoon, K. W.; Young, E.

    The South Pole Telescope (SPT) is a 10-m mm/sub-mm telescope at the Amundsen-Scott South Pole Station. It's primary science goals consist of a galaxy cluster survey for understanding Dark Energy and probing the physics of Inflation through the CMB polarization. Both science goals require exceptional sensitivity necessitating focal planes with many optical elements. The focal planes of the SPT utilize Transition Edge Sensor (TES) bolometers to build arrays of nearly 1000 detectors. In this talk, I will present the TES bolometer technology for both the first SPT focal plane and its upcoming upgrade to a polarization sensitive array.

  19. Astronomy with Small Telescopes

    NASA Astrophysics Data System (ADS)

    Paczyński, Bohdan

    2006-12-01

    The All Sky Automated Survey is monitoring the entire sky to about 14 mag with a cadence of about 1 day; it has discovered about 105 variable stars, most of them new. The instrument used for the survey had an aperture of 7 cm. A search for planetary transits has led to the discovery of about a dozen confirmed planets, so-called hot Jupiters, providing information on planetary masses and radii. Most discoveries were done with telescopes with apertures of 10 cm. We propose a search for optical transients covering the entire sky with a cadence of 10-30 minutes and a limit of 12-14 mag, with an instant verification of all candidate events. The search will be made with a large number of 10 cm instruments, and the verification will be done with 30 cm instruments. We also propose a system to be located at the L1 point of the Earth-Sun system to detect ``killer asteroids.'' With a limiting magnitude of about 18 mag, it could detect 10 m boulders several hours prior to their impact and provide warning against Tunguska-like events, as well as provide news about spectacular but more modest, harmless impacts.

  20. Keck and VLT Observations of Super-Damped Lyman-Alpha Absorbers at z 2- 2.5: Constraints on Chemical Compositions and Physical Conditions

    NASA Astrophysics Data System (ADS)

    Kulkarni, Varsha P.; Som, Debopam; Morrison, Sean; Péroux, Celine; Quiret, Samuel; York, Donald G.

    2015-12-01

    We report Keck/Echellette Spectrograph and Imager and Very Large Telescope/Ultraviolet-Visual Echelle Spectrograph observations of three super-damped Lyα quasar absorbers with H i column densities log NH i ≥ 21.7 at redshifts 2 ≲ z ≲ 2.5. All three absorbers show similar metallicities (˜-1.3 to -1.5 dex), and dust depletion of Fe, Ni, and Mn. Two of the absorbers show supersolar [S/Zn] and [Si/Zn]. We combine our results with those for other damped Lyα a absorbers (DLAs) to examine trends between NH i, metallicity, and dust depletion. A larger fraction of the super-DLAs lie close to or above the line [X/H] = 20.59 - log NH i in the metallicity versus NH i plot, compared to the less gas-rich DLAs, suggesting that super-DLAs are more likely to be rich in molecules. Unfortunately, our data for Q0230-0334 and Q0743+1421 do not cover H2 absorption lines. For Q1418+0718, some H2 lines are covered, but not detected. CO is not detected in any of our absorbers. For DLAs with log NH i < 21.7, we confirm strong correlation between metallicity and Fe depletion, and find a correlation between metallicity and Si depletion. For super-DLAs, these correlations are weaker or absent. The absorbers toward Q0230-0334 and Q1418+0718 show potential detections of weak Lyα emission, implying star formation rates of ˜1.6 and ˜0.7 M⊙ yr-1, respectively (ignoring dust extinction). Upper limits on the electron densities from C ii*/C ii or Si ii*/Si ii are low, but are higher than the median values in less gas-rich DLAs. Finally, systems with log NH i > 21.7 may have somewhat narrower velocity dispersions Δv90 than the less gas-rich DLAs, and may arise in cooler and/or less turbulent gas. Includes observations collected during program ESO 93.A-0422 at the European Southern Observatory (ESO) Very Large Telescope (VLT) with the Ultraviolet-Visual Echelle Spectrograph (UVES) on the 8.2 m telescopes operated at the Paranal Observatory, Chile. Some of the data presented herein were

  1. CCD data acquisition systems at Lick and Keck Observatories

    NASA Technical Reports Server (NTRS)

    Kibrick, R. I.; Stover, R. J.; Conrad, A. R.

    1992-01-01

    This paper will describe and compare two distinct but related CCD data acquisition systems (DAS) currently under development at Lick and Keck Observatories. Although these two systems have a number of major architectural differences, they share a considerable amount of common hardware and software. Both of these new systems build on a large body of proven software that is the foundation of the existing CCD DAS currently in use at Lick Observatory. Both will provide support for reading up to four on-chip amplifiers per CCD and/or reading out mosaics of CCD chips. In addition, they will provide the capability for interactive, real-time adjustment of CCD waveforms for engineering purposes. Each of these two systems is composed of three major subsystems: (1) an instrument computer and its software; (2) a data capture computer and its software; and (3) a CCD/dewar controller and its software. The instrument computer is a Unix workstation, and the functions it provides include user interfaces, the interactive real-time display of CCD images, and the recording of image and FITS header data to disk and/or tape. The data capture computer is responsible for the packaging and high-speed transfer of the CCD pixel data stream into a bulk RAM, and the subsequent transfer of this data to the instrument computer. The CCD/dewar controller generates the waveforms for clocking the CCD, digitizes the pixel data, and transmits it via high-speed link to the data capture computer. It is also responsible for monitoring and controlling the dewar temperature and cryogen levels. Given the number of different types of processors and high-speed data links employed in both systems, a major emphasis of this paper will be on the various forms of interprocessor communications utilized for data transfer and distributed process synchronization.

  2. DEEP KECK u-BAND IMAGING OF THE HUBBLE ULTRA DEEP FIELD: A CATALOG OF z approx 3 LYMAN BREAK GALAXIES

    SciTech Connect

    Rafelski, Marc; Wolfe, Arthur M.; Cooke, Jeff; Chen, H.-W.; Armandroff, Taft E.; Wirth, Gregory D. E-mail: awolfe@ucsd.ed E-mail: hchen@oddjob.uchicago.ed E-mail: gwirth@keck.hawaii.ed

    2009-10-01

    We present a sample of 407 z approx 3 Lyman break galaxies (LBGs) to a limiting isophotal u-band magnitude of 27.6 mag in the Hubble Ultra Deep Field. The LBGs are selected using a combination of photometric redshifts and the u-band drop-out technique enabled by the introduction of an extremely deep u-band image obtained with the Keck I telescope and the blue channel of the Low Resolution Imaging Spectrometer. The Keck u-band image, totaling 9 hr of integration time, has a 1sigma depth of 30.7 mag arcsec{sup -2}, making it one of the most sensitive u-band images ever obtained. The u-band image also substantially improves the accuracy of photometric redshift measurements of approx50% of the z approx 3 LBGs, significantly reducing the traditional degeneracy of colors between z approx 3 and z approx 0.2 galaxies. This sample provides the most sensitive, high-resolution multi-filter imaging of reliably identified z approx 3 LBGs for morphological studies of galaxy formation and evolution and the star formation efficiency of gas at high redshift.

  3. C3R2 - Complete Calibration of the Color-Redshift Relation: Keck spectroscopy to train photometric redshifts for Euclid and WFIRST

    NASA Astrophysics Data System (ADS)

    Stern, Daniel; C3R2 Team

    2017-01-01

    A primary objective of both WFIRST and Euclid is to provide a 3D map of the distribution of matter across a significant fraction of the universe from the weak lensing shear field, but to do so requires robust distances to billions of galaxies. I will report on a multi-semester program, expected to total approximately 40 nights with Keck over the next two years. This program, supporting both the NASA PCOS and COR science goals, will obtain the necessary galaxy spectroscopy to calibrate the color-redshift relation for the Euclid mission, and make significant progress towards the WFIRST requirements. The program, called C3R2 or Complete Calibration of the Color-Redshift Relation, already encompasses 10 allocated nights of NASA Keck Key Strategic Mission Support (PI D. Stern), 12 allocated nights from Caltech (PI J. Cohen), 3 allocated nights from the University of Hawaii (PI D. Sanders), and 1.5 allocated nights from UC-Riverside (PI B. Mobasher). We are also pursuing opportunities at additional 8- to 10-meter class telescopes, including Magellan, VLT and GCT. I will present the motivation for this program, the plans, and current results.

  4. Global Near-IR Maps of Io from Gemini-N and Keck Observations in 2010, with a Specific Emphasis on Kanehekili Fluctus, Janus Patera, and Loki Patera

    NASA Astrophysics Data System (ADS)

    De Pater, I.; Davies, A. G.; Adamkovics, M.; McGregor, A.; Observing Team, G.

    2013-12-01

    We have constructed global maps of Io from observations obtained at 1-5 μm in 2010 using the adaptive optics systems on the Keck and Gemini telescopes. We compare these maps with those obtained in 2001 [1]. Although the total emission from all hot spots combined at each wavelength is similar for the two years, the spatial brightness distribution is very different, a reflection of evolving style and magnitude of volcanic activity. In 2010 thermal emission in the near-infrared was dominated by Loki Patera and Kanehekili Fluctus. We also present new timelines of thermal emission from Kanehekili Fluctus and Loki and Janus Paterae, updating timelines in recent publications [2, 3] with additional Keck adaptive optics data obtained between 2003 and 2010. These new timelines are the most comprehensive plots ever produced of the volcanic thermal emission variability for these or any other locations on Io, utilizing data from multiple ground- and space-based assets. The timeline plot shows that in 2010 Kanehekili Fluctus (as seen by Gemini) was briefly exceptionally brighter than ever seen before, evidence of a short-lived but highly-energetic eruption episode. Acknowledgements: AGD is supported by a grant from the NASA OPR Program. References: [1] Marchis et al. (2005) Icarus, 176, 96-122. [2] Davies et al. (2012) Icarus, 221, 466-470. [3] Rathbun and Spencer (2010) Icarus, 209, 625-630.

  5. Spatially resolved emission of a high-redshift DLA galaxy with the Keck/OSIRIS IFU

    SciTech Connect

    Jorgenson, Regina A.; Wolfe, Arthur M.

    2014-04-10

    We present the first Keck/OSIRIS infrared IFU observations of a high-redshift damped Lyα (DLA) galaxy detected in the line of sight to a background quasar. By utilizing the Laser Guide Star Adaptive Optics to reduce the quasar point-spread function to FWHM ∼ 0.''15, we were able to search for and map the foreground DLA emission free from the quasar contamination. We present maps of the Hα and [O III] λλ5007, 4959 emission of DLA 2222–0946 at a redshift of z ∼ 2.35. From the composite spectrum over the Hα emission region, we measure a star formation rate of 9.5 ± 1.0 M {sub ☉} yr{sup –1} and a dynamical mass of M {sub dyn} = 6.1 × 10{sup 9} M {sub ☉}. The average star formation rate surface density is (Σ{sub SFR}) = 0.55 M {sub ☉} yr{sup –1} kpc{sup –2}, with a central peak of 1.7 M {sub ☉} yr{sup –1} kpc{sup –2}. Using the standard Kennicutt-Schmidt relation, this corresponds to a gas mass surface density of Σ{sub gas} = 243 M {sub ☉} pc{sup –2}. Integrating over the size of the galaxy, we find a total gas mass of M {sub gas} = 4.2 × 10{sup 9} M {sub ☉}. We estimate the gas fraction of DLA 2222–0946 to be f {sub gas} ∼ 40%. We detect [N II] λ6583 emission at 3σ significance with a flux corresponding to a metallicity of 75% solar. Comparing this metallicity with that derived from the low-ion absorption gas ∼6 kpc away, ∼30% solar, indicates possible evidence for a metallicity gradient or enriched in/outflow of gas. Kinematically, both Hα and [O III] emission show relatively constant velocity fields over the central galactic region. While we detect some red and blueshifted clumps of emission, they do not correspond with rotational signatures that support an edge-on disk interpretation.

  6. The Keck Planet Search: Detectability and the Minimum Mass and Orbital Period Distribution of Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Cumming, Andrew; Butler, R. Paul; Marcy, Geoffrey W.; Vogt, Steven S.; Wright, Jason T.; Fischer, Debra A.

    2008-05-01

    We analyze 8 years of precise radial velocity measurements from the Keck Planet Search, characterizing the detection threshold, selection effects, and completeness of the survey. We first carry out a systematic search for planets, by assessing the false-alarm probability associated with Keplerian orbit fits to the data. This allows us to understand the detection threshold for each star in terms of the number and time baseline of the observations, and the underlying “noise” from measurement errors, intrinsic stellar jitter, or additional low-mass planets. We show that all planets with orbital periods P < 2000 days, velocity amplitudes K > 20 m s-1, and eccentricities e ≲ 0.6 have been announced, and we summarize the candidates at lower amplitudes and longer orbital periods. For the remaining stars, we calculate upper limits on the velocity amplitude of a companion. For orbital periods less than the duration of the observations, these are typically 10 m s-1 and increase ∝ P2 for longer periods. We then use the nondetections to derive completeness corrections at low amplitudes and long orbital periods and discuss the resulting distribution of minimum mass and orbital period. We give the fraction of stars with a planet as a function of minimum mass and orbital period and extrapolate to long-period orbits and low planet masses. A power-law fit for planet masses >0.3 MJ and periods < 2000 days gives a mass-period distribution dN = CMα Pβ d ln Md ln P with α = -0.31 ± 0.2, β = 0.26 ± 0.1, and the normalization constant C such that 10.5% of solar type stars have a planet with mass in the range 0.3–10 MJ and orbital period 2–2000 days. The orbital period distribution shows an increase in the planet fraction by a factor of ≈5 for orbital periods ≳300 days. Extrapolation gives 17%–20% of stars having gas giant planets within 20 AU. Finally, we constrain the occurrence rate of planets orbiting M dwarfs compared to FGK dwarfs, taking into account

  7. Efficient method for the reduction of large piston errors in segmented-mirror telescopes.

    PubMed

    Chanan, Gary; Pintó, Agustí

    2004-06-01

    Phase discontinuity sensing (PDS) is one of two successful approaches to segment phasing that are currently in use at the Keck telescopes, but it has only a limited capture range. We describe and present numerical simulations of a broadband version of the current (narrowband) PDS algorithm that can extend the capture range from 0.4 to 40 microns. Like the original algorithm, the new broadband PDS algorithm requires no special-purpose hardware but only a high-resolution area detector operating in the 2-3-microns range. The potential application of this algorithm to extremely large telescopes is also discussed.

  8. Arrays vs. single telescopes

    NASA Astrophysics Data System (ADS)

    Johnson, H. L.

    The question of the relative efficiencies of telescope arrays versus an equivalent mirror-area very large telescope is re-examined and summarized. Four separate investigations by Bowen, Johnson and Richards, Code, and Disney all came to the same conclusion: that an array of telescopes is superior, both scientifically and economically, to a single very large telescope. The costs of recently completed telescopes are compared. The costs of arrays of telescopes are shown to be significantly lower than that of a single, very large telescope, with the further advantage that because existing, proven, designs can be used, no engineering 'break-throughs' are needed.

  9. CMB B-mode Polarization Measurements and constraints on Primordial Gravitational Waves from the BICEP/Keck Program at South Pole

    NASA Astrophysics Data System (ADS)

    Kovac, John; Bicep/Keck Collaboration

    2017-01-01

    The BICEP/Keck Array cosmic microwave background (CMB) polarization experiments located at the South Pole are a series of small-aperture refracting telescopes designed to probe the degree-scale B-mode signature of primordial gravitational waves. These highly-targeted experiments have produced the world's deepest maps of CMB polarization, leading to the most stringent constraints on the tensor-to-scalar ratio to date: r < 0 . 09 from B-modes alone, and r < 0 . 07 in combination with other datasets. These limits are rapidly improving with ongoing measurements at the multiple frequencies needed to separate Galactic foregrounds from the CMB, and in combination with higher-resolution experiments to remove B-modes induced by gravitational lensing. I will review the current status of measurements and results, and will discuss the challenges that will be confronted as measurements reach sensitivities to primordial gravitational waves at a level r < 0 . 01 and below within the next several years.

  10. Rest-Frame R-band Light Curve of a z ~ 1.3 Supernova Obtained with Keck Laser Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Melbourne, J.; Dawson, K. S.; Koo, D. C.; Max, C.; Larkin, J. E.; Wright, S. A.; Steinbring, E.; Barczys, M.; Aldering, G.; Barbary, K.; Doi, M.; Fadeyev, V.; Goldhaber, G.; Hattori, T.; Ihara, Y.; Kashikawa, N.; Konishi, K.; Kowalski, M.; Kuznetsova, N.; Lidman, C.; Morokuma, T.; Perlmutter, S.; Rubin, D.; Schlegel, D. J.; Spadafora, A. L.; Takanashi, N.; Yasuda, N.

    2007-06-01

    We present Keck diffraction-limited H-band photometry of a z~1.3 Type Ia supernova (SN) candidate, first identified in a Hubble Space Telescope search for SNe in massive high-redshift galaxy clusters. The adaptive optics (AO) data were obtained with the Laser Guide Star facility during four observing runs from 2005 September to November. In the analysis of data from the observing run nearest to maximum SN brightness, the SN was found to have a magnitude H=23.9+/-0.14 (Vega). We present the H-band (approximately rest-frame R) light curve and provide a detailed analysis of the AO photometric uncertainties. By constraining the aperture correction with a nearby (4'' separation) star we achieve 0.14 mag photometric precision, despite the spatially varying AO point-spread function.

  11. Spatially resolved Spectroscopy of Europa’s Large-scale Compositional Units at 3–4 μm with Keck NIRSPEC

    NASA Astrophysics Data System (ADS)

    Fischer, P. D.; Brown, M. E.; Trumbo, S. K.; Hand, K. P.

    2017-01-01

    We present spatially resolved spectroscopic observations of Europa’s surface at 3–4 μm obtained with the near-infrared spectrograph and adaptive optics system on the Keck II telescope. These are the highest quality spatially resolved reflectance spectra of Europa’s surface at 3–4 μm. The observations spatially resolve Europa’s large-scale compositional units at a resolution of several hundred kilometers. The spectra show distinct features and geographic variations associated with known compositional units; in particular, large-scale leading hemisphere chaos shows a characteristic longward shift in peak reflectance near 3.7 μm compared to icy regions. These observations complement previous spectra of large-scale chaos, and can aid efforts to identify the endogenous non-ice species.

  12. A KECK/LRIS SPATIALLY RESOLVED SPECTROSCOPIC STUDY OF A LINER GALAXY SDSS J091628.05+420818.7

    SciTech Connect

    Bae, Hyun-Jin; Yoon, Suk-Jin; Woo, Jong-Hak; Yagi, Masafumi; Yoshida, Michitoshi

    2012-07-01

    Using spatially resolved spectra obtained with the Low Resolution Imaging Spectrometer at the Keck I telescope, we investigate the nature of ionizing sources and kinematic properties of emission-line gas in a LINER galaxy SDSS J091628.05+420818.7, which is a nearby (z = 0.0241) and bright (M{sub r} = -20.2) early-type galaxy. After subtracting stellar absorption features using a combination of simple stellar population models, we measure the flux, line-of-sight velocity, and velocity dispersion of four emission lines, i.e., H{alpha}, H{beta}, [O III] {lambda}5007, and [N II] {lambda}6584, to study radial change of emission-line fluxes and velocities. Compared to the point-spread function of the observation, the emission-line region is slightly extended but comparable to the seeing size. The central concentration of emission-line gas suggests that ionization is triggered by a nuclear source, excluding old stellar population as ionizing sources. We find that emission-line gas is counter-rotating with respect to stellar component and that the [O III] {lambda}5007 line is blueshifted compared to other emission lines, possibly due to an outflow.

  13. KECK ADAPTIVE OPTICS OBSERVATIONS OF THE PROTOSTELLAR DISK AROUND RADIO SOURCE I IN THE ORION KLEINMANN-LOW NEBULA

    SciTech Connect

    Sitarski, Breann N.; Morris, Mark R.; Becklin, E. E.; Ghez, Andrea M.; Lu, Jessica R.; Duchene, Gaspard; Stolte, Andrea; Zinnecker, Hans

    2013-06-20

    We have made the first detection of a near-infrared counterpart associated with the disk around Radio Source ''I'', a massive protostar in the Kleinmann-Low nebula in Orion, using imaging with laser guide star adaptive optics on the Keck II telescope. The infrared emission is evident in images acquired using L' (3.8 {mu}m) and Ms (4.7 {mu}m) filters and is not detectable at K' (2.1 {mu}m). The observed morphology strongly suggests that we are seeing some combination of scattered and thermal light emanating from the disk. The disk is also manifest in the L'/Ms flux ratio image. We interpret the near-infrared emission as the illuminated surface of a nearly edge-on disk, oriented so that only the northern face is visible; the opposite surface remains hidden by the disk. We do not see infrared radiation associated directly with the star proposed to be associated with Source ''I''. The data also suggest that there is a cavity above and below the disk that is oriented perpendicular to the disk and is sculpted by the known, strong outflow from the inner disk of Source I. We compare our data to models of a protostar with a surrounding disk, envelope, and wind-blown cavity in order to elucidate the nature of the disk around Radio Source I.

  14. Ground-based observations of Saturn's H3+ aurora and ring rain from Keck in 2013

    NASA Astrophysics Data System (ADS)

    O'Donoghue, J.; Melin, H.; Stallard, T.; Provan, G.; Moore, L.; Badman, S. V.; Baines, K. H.; Miller, S.; Cowley, S. W. H.

    2014-12-01

    The ground-based 10-metre Keck telescope was used to probe Saturn's H3+ ionosphere in 2013. The slit on the high resolution near infrared spectrometer (NIRSPEC; (R~25,000) was aligned pole-to-pole along Saturn's rotational axis at local noon. This is also aligned (within uncertainties) to the effectively dipolar magnetic field. Four polar/auroral regions of Saturn's ionosphere were measured simultaneously as the planet rotated: 1) the northern noon main auroral oval; 2) the northern midnight main oval; 3) the northern polar cap and 4) the southern main oval at noon. The results here contain twenty-three H3+ temperatures, column densities and total emissions located at the above regions spread over timescales of both hours and days. The main findings of this study are that ionospheric temperatures in the northern main oval are cooler than their southern counterparts by tens of K; supportive of the hypothesis that the total thermospheric heating rate (Joule heating and ion drag) is inversely proportional to magnetic field strength. The main oval H3+ density and emission is lower at northern midnight than at noon, and this is in agreement with an electron influx peaking at 08:00 Saturn local time and having a minimum at midnight. When ordering the northern main oval parameters of H3+ as a function of the oscillation period seen in Saturn's magnetic field - the planetary period oscillation (PPO) phase - we see a large peak in H3+ density and emission at ˜110° phase, with a full-width at half-maximum (FWHM) of ˜40°. This seems to indicate that the influx of electrons associated with the PPO phase at 90° is responsible at least in part for the behavior of all H3+ parameters. In addition to the auroral/polar data we also present the latest results from observations of Saturn's mid-to-low latitude H3+ emission. This emission is thought to be modulated by charged water product influx which flows into the planet along magnetic field lines from Saturn's rings, i.e. ring

  15. Gemini and Keck Observations of Slowly Rotating, Bilobate Active Asteroid (300163)

    NASA Astrophysics Data System (ADS)

    Waniak, Waclaw; Drahus, Michal

    2016-10-01

    One of the most puzzling questions regarding Active Asteroids is the mechanism of their activation. While some Active Asteroids show protracted and often recurrent mass loss, consistent with seasonal ice sublimation, some other eject dust impulsively as a result of a catastrophic disruption (e.g. Jewitt et al. 2015, Asteroids IV, 221). It has been suggested that ice can be excavated from the cold near-surface interior by an impact (Hsieh & Jewitt 2006, Science 312, 561) or, for small objects susceptible to YORP torques, by near-critical spin rate (Sheppard & Trujillo 2014, AJ 149, 44). But impact and rapid spin can also cause a catastrophic disruption (e.g. Jewitt et al. 2015, Asteroids IV, 221). It therefore becomes apparent that the different types of mass loss observed in Active Asteroids can be best classified and understood based on the nucleus spin rates (Drahus et al. 2015, ApJL 802, L8), but unfortunately the rotation periods have been measured for a very limited number of these objects. With this in mind we have initiated a survey of light curves of small Active Asteroids on the largest ground-based optical telescopes. Here we present the results for (300163), also known as 288P and 2006 VW139, which is a small 2.6-km sized asteroid that exhibited a comet-like activity over 100 days in the second half of 2011 (Hsieh et al. 2012, ApJL 748, L15; Licandro et al. 2013, A&A 550, A17; Agarwal et al. 2016, AJ 151, 12). Using Keck/DEIMOS and Gemini/GMOS-S working in tandem on UT 2015 May 21-22 we have detected an inactive nucleus and measured a complete, dense, high-S/N rotational light curve. The light curve has a double-peaked period of 16 hours, an amplitude of 0.4 mag, and moderately narrow minima suggesting a bilobate or contact-binary shape. The long rotation period clearly demonstrates a non-rotational origin of activity of this object, consistent with an impact. Furthermore, among the five small Active Asteroids with known rotation periods (300163) is only

  16. Control System Modeling for the Thirty Meter Telescope Primary Mirror

    NASA Technical Reports Server (NTRS)

    MacMynowski, Douglas G.; Thompson, Peter M.; Shelton, J. Chris; Roberts, Lewis C., Jr.; Colavita, M. Mark; Sirota, Mark J.

    2011-01-01

    The Thirty Meter Telescope primary mirror is composed of 492 segments that are controlled to high precision in the presence of wind and vibration disturbances, despite the interaction with structural dynamics. The higher bandwidth and larger number of segments compared with the Keck telescopes requires greater attention to modeling to ensure success. We focus here on the development and validation of a suite of quasi-static and dynamic modeling tools required to support the design process, including robustness verification, performance estimation, and requirements flowdown. Models are used to predict the dynamic response due to wind and vibration disturbances, estimate achievable bandwidth in the presence of control-structure-interaction (CSI) and uncertainty in the interaction matrix, and simulate and analyze control algorithms and strategies, e.g. for control of focus-mode, and sensor calibration. Representative results illustrate TMT performance scaling with parameters, but the emphasis is on the modeling framework itself.

  17. Estimating phase errors from pupil discontinuities from simulated on sky data: examples with VLT and Keck

    NASA Astrophysics Data System (ADS)

    Lamb, Masen; Correia, Carlos; Sauvage, Jean-François; Véran, Jean-Pierre; Andersen, David; Vigan, Arthur; Wizinowich, Peter; van Dam, Marcos; Mugnier, Laurent; Bond, Charlotte

    2016-07-01

    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.

  18. Crack growth of 10M Ni-Mn-Ga material in cyclic mechanical loading

    NASA Astrophysics Data System (ADS)

    Aaltio, I.; Ge, Y.; Pulkkinen, H.; Sjöberg, A.; Söderberg, O.; Liu, X. W.; Hannula, S.-P.

    The 10M martensitic Ni-Mn-Ga single crystal materials are usually applied in the magneto-mechanical actuators. Therefore, it is important to know the possible effect of the long-term cyclic shape changes on their structure and behavior. This can be evaluated with the mechanical fatigue testing. In the present study, the single crystal 10M Ni-Mn-Ga samples of different compositions were applied to strain-controlled uniaxial mechanical cycling in the multivariant state at ambient temperature. The experiments revealed distinctive changes of the twin variant structure, especially in the mobile twin area, density of twin boundaries, and in the tendency for fatigue crack growth. Characterization of the crack surface showed that the cracks in the microscale grow in a step-wise manner on specific crystallographic planes, i.e, twin boundary planes, but that the macroscopic crack does not occur only along crystallographic directions.

  19. Development of laser guide stars and adaptive optics for large astronomical telescopes

    SciTech Connect

    Max, C.E.; Avicola, K.; Bissinger, H.; Brase, J.M.; Gavel, D.T.; Friedman, H.; Morris, J.R.; Olivier, S.S.; Rapp, D.; Salmon, J.T.; Waltjen, K.

    1992-06-29

    We describe a feasibility experiment to demonstrate high-order adaptive optics using a sodium-layer laser guide star. We use the copper-vapor-pumped dye lasers developed for LLNL`s atomic Vapor Laser Isotope Separation program to create the laser guide star. Closed-loop adaptive corrections will be accomplished using a 69-subaperture adaptive optics system on a one-meter telescope at LLNL. The laser bream is projected upwards from a beam director approximately 5 meters away from the main telescope, and is expected to form a spot 1-2 meters in diameter at the atmospheric sodium layer (95 km altitude). We describe the overall system architecture and adaptive optics components, and analyze the expected performance. Our long-term goal is to develop sodium-layer laser guide stars and adaptive optics for large astronomical telescopes. We discuss preliminary design trade-offs for the Keck Telescope at Mauna Kea.

  20. Development of laser guide stars and adaptive optics for large astronomical telescopes

    SciTech Connect

    Max, C.E.; Avicola, K.; Bissinger, H.; Brase, J.M.; Gavel, D.T.; Friedman, H.; Morris, J.R.; Olivier, S.S.; Rapp, D.; Salmon, J.T.; Waltjen, K.

    1992-06-29

    We describe a feasibility experiment to demonstrate high-order adaptive optics using a sodium-layer laser guide star. We use the copper-vapor-pumped dye lasers developed for LLNL's atomic Vapor Laser Isotope Separation program to create the laser guide star. Closed-loop adaptive corrections will be accomplished using a 69-subaperture adaptive optics system on a one-meter telescope at LLNL. The laser bream is projected upwards from a beam director approximately 5 meters away from the main telescope, and is expected to form a spot 1-2 meters in diameter at the atmospheric sodium layer (95 km altitude). We describe the overall system architecture and adaptive optics components, and analyze the expected performance. Our long-term goal is to develop sodium-layer laser guide stars and adaptive optics for large astronomical telescopes. We discuss preliminary design trade-offs for the Keck Telescope at Mauna Kea.

  1. High-Resolution N-Band Observations of the Nova RS Ophiuchi with the Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Barry, R. K.; Danchi, W. C.; Sokoloski, J. L.; Koresko, C.; Wisniewski, J. P.; Serabyn, E.; Traub, W.; Kuchner, M.; Greenhouse, M. A.

    2007-01-01

    We report new observations of the nova RS Ophiuchi (RS Oph) using the Keck Interferometer Nulling Instrument, approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. The Keck Interferometer Nuller (KIN) operates in K-band from 8 to 12.5 pm in a nulling mode, which means that the central broad-band interference fringe is a dark fringe - with an angular width of 25 mas at mid band - rather than the bright fringe used ill a conventional optical interferometer. In this mode the stellar light itself is suppressed by the destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. By subsequently shifting the neighboring bright fringe onto the center of the source brightness distribution and integrating, a second spatial regime dominated by light from the central portion of the source is almost simultaneously sampled. The nulling technique is the sparse aperture equivalent of the conventional corongraphic technique used in filled aperture telescopes. By fitting the unique KIK inner and outer spatial regime data, we have obtained an angular size of the mid-infrared continuum of 6.2, 4.0. or 5.4 mas for a disk profile, gaussian profile (fwhm), and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission located in the inner spatial regime relative to the outer regime. There is also evidence of a 9.7 micron silicate feature seen outside of this region. Importantly, we see spectral lines excited by the nova flash in the outer region before the blast wave reaches these regions. These lines are from neutral, weakly excited atoms which support the following interpretation. We discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power

  2. Telescope performance at the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Hill, John M.; Rothberg, Barry; Christou, Julian C.; Summers, Kellee R.; Summers, Douglas M.

    2016-07-01

    The Large Binocular Telescope Observatory is a collaboration between institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio and Virginia. The telescope uses two 8.4-m diameter primary mirrors mounted sideby- side on the same AZ-EL mount to produce a collecting area equivalent to an 11.8-meter aperture. Adaptive optics loops are routinely closed with natural stars on both sides for sided and combined beam observations. Rayleigh laser guide stars provide GLAO seeing improvement. With the telescope now in operation for 10 years, we report on various statistics of telescope performance and seeing-limited image quality. Statistics of telescope performance are reported in the areas of off-axis guiding, open-loop mount tracking, active optics and vibration. Delivered image quality is reported as measured by the DIMM and several guide cameras as a function of other parameters such as temperature and wind velocity. Projects to improve image quality and dome seeing are underway.

  3. DISSOLUTION OF PLUTONIUM METAL IN 8-10 M NITRIC ACID

    SciTech Connect

    Rudisill, T.; Pierce, R.

    2012-02-21

    The H-Canyon facility will be used to dissolve Pu metal for subsequent purification and conversion to plutonium dioxide (PuO{sub 2}) using Phase II of HB-Line. To support the new mission, the development of a Pu metal dissolution flowsheet which utilizes concentrated (8-10 M) nitric acid (HNO{sub 3}) solutions containing potassium fluoride (KF) is required. Dissolution of Pu metal in concentrated HNO{sub 3} is desired to eliminate the need to adjust the solution acidity prior to purification by anion exchange. The preferred flowsheet would use 8-10 M HNO{sub 3}, 0.015-0.07 M KF, and 0.5-1.0 g/L Gd to dissolve the Pu up to 6.75 g/L. An alternate flowsheet would use 8-10 M HNO{sub 3}, 0.1-0.2 M KF, and 1-2 g/L B to dissolve the Pu. The targeted average Pu metal dissolution rate is 20 mg/min-cm{sup 2}, which is sufficient to dissolve a 'standard' 2250-g Pu metal button in 24 h. Plutonium metal dissolution rate measurements showed that if Gd is used as the nuclear poison, the optimum dissolution conditions occur in 10 M HNO{sub 3}, 0.04-0.05 M KF, and 0.5-1.0 g/L Gd at 112 to 116 C (boiling). These conditions will result in an estimated Pu metal dissolution rate of {approx}11-15 mg/min-cm{sup 2} and will result in dissolution times of 36-48 h for standard buttons. The recommended minimum and maximum KF concentrations are 0.03 M and 0.07 M, respectively. The maximum KF concentration is dictated by a potential room-temperature Pu-Gd-F precipitation issue at low Pu concentrations. The purpose of the experimental work described in this report was two-fold. Initially a series of screening experiments was performed to measure the dissolution rate of Pu metal as functions of the HNO{sub 3}, KF, and Gd or B concentrations. The objective of the screening tests was to propose optimized conditions for subsequent flowsheet demonstration tests. Based on the rate measurements, this study found that optimal dissolution conditions in solutions containing 0.5-1.0 g/L Gd occurred in 8-10

  4. The space telescope

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Papers concerning the development of the Space Telescope which were presented at the Twenty-first Annual Meeting of the American Astronautical Society in August, 1975 are included. Mission planning, telescope performance, optical detectors, mirror construction, pointing and control systems, data management, and maintenance of the telescope are discussed.

  5. Telescopes and space exploration

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Maran, S. P.

    1976-01-01

    The necessity for different types of telescopes for astronomical investigations is discussed. Major findings in modern astronomy by ground-based and spaceborne telescopes are presented. Observations of the Crab Nebula, solar flares, interstellar gas, and the Black Hole are described. The theory of the oscillating universe is explored. Operating and planned telescopes are described.

  6. The Challenge of Governance. Teacher's Guide [and Student Text]. W.M. Keck Foundation Series.

    ERIC Educational Resources Information Center

    Croddy, Marshall; Degelman, Charles; Hayes, Bill

    This teacher's guide and student text is the fourth volume in the W. M. Keck Foundation Series. The guide, which is designed to provide instructional support for classroom use of "The Challenge of Governance," gives teachers an opportunity to review content from the National Standards for Civics and Government for High School with…

  7. KALI Camera: mid-infrared camera for the Keck Interferometer Nuller

    NASA Astrophysics Data System (ADS)

    Creech-Eakman, Michelle J.; Moore, James D.; Palmer, Dean L.; Serabyn, Eugene

    2003-03-01

    We present a brief overview of the KALI Camera, the mid-infrared camera for the Keck Interferometer Nulling Project, built at the Jet Propulsion Laboratory. The instrument utilizes mainly transmissive optics in four identical beam paths to spatially and spectrally filter, polarize, spectrally disperse and image the incoming 7-14 micron light from the four outputs of the Keck Nulling Beam Combiner onto a custom Boeing/DRS High Flux 128 X 128 BIB array. The electronics use a combination of JPL and Wallace Instruments boards to interface the array readout with the existing real-time control system of the Keck Interferometer. The cryogenic dewar, built by IR Laboratories, uses liquid nitrogen and liquid helium to cool the optics and the array, and includes six externally motorized mechanisms for aperture and pinhole control, focus, and optical component selection. The instrument will be assembled and tested through the summer of 2002, and is planned to be deployed as part of the Keck Interferometer Nulling experiment in 2003.

  8. LES Modeling of Lateral Dispersion in the Ocean on Scales of 10 m to 10 km

    DTIC Science & Technology

    2015-10-20

    Report 3. DATES COVERED (From - To) 01/07/2010 – 06/06/2015 4. TITLE AND SUBTITLE LES Modeling of Lateral Dispersion in the Ocean on Scales of 10...ocean on scales of 0.1-10 km that can be implemented in larger- scale ocean models. These parameterizations will incorporate the effects of local...Distribution approved for public release; distribution is unlimited. Final Report LES Modeling of Lateral Dispersion on Scales of 10 m to 10 km M.-Pascale

  9. Advanced technology optical telescopes IV; Proceedings of the Meeting, Tucson, AZ, Feb. 12-16, 1990. Parts 1 & 2

    NASA Technical Reports Server (NTRS)

    Barr, Lawrence D. (Editor)

    1990-01-01

    The present conference on the current status of large, advanced-technology optical telescope development and construction projects discusses topics on such factors as their novel optical system designs, the use of phased arrays, seeing and site performance factors, mirror fabrication and testing, pointing and tracking techniques, mirror thermal control, structural design strategies, mirror supports and coatings, and the control of segmented mirrors. Attention is given to the proposed implementation of the VLT Interferometer, the first diffraction-limited astronomical images with adaptive optics, a fiber-optic telescope using a large cross-section image-transmitting bundle, the design of wide-field arrays, Hartmann test data reductions, liquid mirrors, inertial drives for telescope pointing, temperature control of large honeycomb mirrors, evaporative coatings for very large telescope mirrors, and the W. M. Keck telescope's primary mirror active control system software.

  10. ATST telescope mount: telescope of machine tool

    NASA Astrophysics Data System (ADS)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  11. A Keck Search for Faint Satellites of Pluto in Support of New Horizons

    NASA Astrophysics Data System (ADS)

    Merline, William J.; Weaver, H. A.; Tamblyn, P. M.; Neyman, C.; Stern, S. A.; Carry, B.; Spencer, J. R.; Conrad, A. R.; Showalter, M. A.; Olkin, C. B.; Steffl, A. J.; Sheppard, S. S.; Buie, M. W.; Enke, B. L.

    2012-10-01

    We report on our efforts to search for faint satellites of Pluto using Keck 2 adaptive optics (AO). Last year, using HST, Showalter et al. 2011 (IAUC 9221) discovered a new, faint satellite ("P4") around Pluto, demonstrating that Pluto is even richer with orbiting material than was thought previously. That discovery led to speculations that these small satellites could be a source of debris (from random impacts) that could pose a hazard to the New Horizons (NH) spacecraft during its 2015 Pluto flyby. The ejecta would form a cloud around Pluto. The NH project began an aggressive program of HST- and ground-based studies to identify additional as-yet-unseen satellites or debris rings in the system. Only several days into their campaign, a 5th satellite "P5" was discovered with HST (Showalter et al. 2012, IAUC 9253). The output of these studies will be used to plan a contingency ("safe-haven") trajectory through the system. The Keck observations support and complement the new HST observations. Real objects in the HST images may be hidden by bad pixels or diffraction spikes, and Keck may have advantages in some regions of parameter space, such as interior to Charon. r Observing in a near-IR band, the Keck imaging provides additional constraints on the objects, but this makes the observations particularly challenging because of the sky brightness. We have made an effort to optimize the Keck AO observations. Near-IR imaging requires tradeoffs between sky brightness and post-correction Strehl. Expectations and our early results favor H-band in typical conditions. Contrary to prior experience with V 14 targets, we find Laser-Guide-Star AO correction to be far more effective than using Pluto as the wavefront source (NGS). We have achieved imaging that could detect satellites smaller than Nix at good S/N, even in a relatively short (15 min) span.

  12. Bioaerosol sampling by a personal rotating cup sampler CIP 10-M.

    PubMed

    Görner, Peter; Fabriès, Jean-François; Duquenne, Philippe; Witschger, Olivier; Wrobel, Richard

    2006-01-01

    High concentrations of bioaerosols containing bacterial, fungal and biotoxinic matter are encountered in many workplaces, e.g. solid waste treatment plants, waste water treatment plants and sewage networks. A personal bioaerosol sampler, the CIP 10-M (M-microbiologic), has been developed to measure worker exposure to airborne biological agents. This sampler is battery operated; it is light and easy to wear and offers full work shift autonomy. It can sample much higher concentrations than biological impactors and limits the mechanical stress on the microorganisms. Biological particles are collected in 2 ml of liquid medium inside a rotating cup fitted with radial vanes to maintain an air flow rate of 10 l min(-1) at a rotational speed of approximately 7,000 rpm. The rotating cup is made of sterilisable material. The sampled particles follow a helicoidal trajectory as they are pushed to the surface of the liquid by centrifugal force, which creates a thin vertical liquid layer. Sterile water or another collecting liquid can be used. Three particle size selectors allow health-related aerosol fractions to be sampled according to international conventions. The sampled microbiological particles can be easily recovered for counting, incubation or further biochemical analysis, e.g., for airborne endotoxins. Its physical sampling efficiency was laboratory tested and field trials were carried out in industrial waste management conditions. The results indicate satisfactory collection efficiency, whilst experimental application has demonstrated the usefulness of the CIP 10-M personal sampler for individual bioaerosol exposure monitoring.

  13. Solar Rejection Filter for Large Telescopes

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid; Lesh, James

    2009-01-01

    To reject solar radiation photons at the front aperture for large telescopes, a mosaic of large transmission mode filters is placed in front of the telescope or at the aperture of the dome. Filtering options for effective rejection of sunlight include a smaller filter down-path near the focus of the telescope, and a large-diameter filter located in the front of the main aperture. Two types of large filters are viable: reflectance mode and transmittance mode. In the case of reflectance mode, a dielectric coating on a suitable substrate (e.g. a low-thermal-expansion glass) is arranged to reflect only a single, narrow wavelength and to efficiently transmit all other wavelengths. These coatings are commonly referred to as notch filter. In this case, the large mirror located in front of the telescope aperture reflects the received (signal and background) light into the telescope. In the case of transmittance mode, a dielectric coating on a suitable substrate (glass, sapphire, clear plastic, membrane, and the like) is arranged to transmit only a single wavelength and to reject all other wavelengths (visible and near IR) of light. The substrate of the large filter will determine its mass. At first glance, a large optical filter with a diameter of up to 10 m, located in front of the main aperture, would require a significant thickness to avoid sagging. However, a segmented filter supported by a structurally rugged grid can support smaller filters. The obscuration introduced by the grid is minimal because the total area can be made insignificant. This configuration can be detrimental to a diffraction- limited telescope due to diffraction effects at the edges of each sub-panel. However, no discernable degradation would result for a 20 diffraction-limit telescope (a photon bucket). Even the small amount of sagging in each subpanel should have minimal effect in the performance of a non-diffraction limited telescope because the part has no appreciable optical power. If the

  14. Space Infrared Telescope Facility (SIRTF) telescope overview

    NASA Technical Reports Server (NTRS)

    Schember, Helene; Manhart, Paul; Guiar, Cecilia; Stevens, James H.

    1991-01-01

    The Space Infrared Telescope Facility (SIRTF) will be the first true infrared observatory in space, building upon the technical and scientific experience gained through its two NASA survey-oriented predecessors: the Infrared Astronomical Satellite and the Cosmic Background Explorer. During its minimum five year lifetime, the SIRTF will perform pointed scientific observations at wavelengths from 1.8 to 1200 microns with an increase in sensitivity over previous missions of several orders of magnitude. This paper discusses a candidate design for the SIRTF telescope, encompassing optics, cryostat, and instrument accommodation, which has been undertaken to provide a fulcrum for the development of functional requirements, interface definition, risk assessment and cost. The telescope optics employ a baffled Ritchey-Chretien Cassegrain system with a 1-m class primary mirror, an active secondary mirror, and a stationary facetted tertiary mirror. The optics are embedded in a large superfluid He cryostat designed to maintain the entire telescope-instrument system at temperatures below 3 K.

  15. Hubble Space Telescope Optical Telescope Assembly

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This image illustrates the Hubble Space Telescope's (HST's) Optical Telescope Assembly (OTA). One of the three major elements of the HST, the OTA consists of two mirrors (a primary mirror and a secondary mirror), support trusses, and the focal plane structure. The mirrors collect and focus light from selected celestial objects and are housed near the center of the telescope. The primary mirror captures light from objects in space and focuses it toward the secondary mirror. The secondary mirror redirects the light to a focal plane where the Scientific Instruments are located. The primary mirror is 94.5 inches (2.4 meters) in diameter and the secondary mirror is 12.2 inches (0.3 meters) in diameter. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth Orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from the Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The spacecraft is 42.5 feet (13 meters) long and weighs 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  16. A co-phasing technique for segmented mirror telescopes

    NASA Astrophysics Data System (ADS)

    Jacob, Annu; Parihar, Padmakar

    2015-06-01

    In the new era of astronomy, we go for bigger telescopes having segmented primary and secondary mirrors. But once segmentation is done, aligning and phasing mirror segments so that altogether they act like a monolithic mirror of a large diameter, becomes critical. Co-phasing is a complex task that needed to be done after aligning the segments. Diffraction limited resolution is only possible by a large segmented telescope, if mirror segments are co-phased. Co-phasing techniques rely on physical optics and in one of the technique implemented in Keck telescope is based on analysis of diffraction pattern generated by Shack Hartmann sensor. This same technique is being further explored by us in laboratory experimentation. In this paper we present our effort to develop a simple but robust phasing technique for a large segmented mirror telescope proposed to be installed in India. After rigorous mathematical exercise , analytical formulation for the phasing technique is derived, which is further used to simulate in MATLAB. The MATLAB results are cross checked with the ZEMAX. There after, a preliminary laboratory experiment has been conducted to check the feasibility of using this technique for phasing segmented mirrors.

  17. The Thirty Meter Telescope (TMT): An International Observatory

    NASA Astrophysics Data System (ADS)

    Sanders, Gary H.

    2013-06-01

    The Thirty Meter Telescope (TMT) will be the first truly global ground-based optical/infrared observatory. It will initiate the era of extremely large (30-meter class) telescopes with diffraction limited performance from its vantage point in the northern hemisphere on Mauna Kea, Hawaii, USA. The astronomy communities of India, Canada, China, Japan and the USA are shaping its science goals, suite of instrumentation and the system design of the TMT observatory. With large and open Nasmyth-focus platforms for generations of science instruments, TMT will have the versatility and flexibility for its envisioned 50 years of forefront astronomy. The TMT design employs the filled-aperture finely-segmented primary mirror technology pioneered with the W.M. Keck 10-meter telescopes. With TMT's 492 segments optically phased, and by employing laser guide star assisted multi-conjugate adaptive optics, TMT will achieve the full diffraction limited performance of its 30-meter aperture, enabling unprecedented wide field imaging and multi-object spectroscopy. The TMT project is a global effort of its partners with all partners contributing to the design, technology development, construction and scientific use of the observatory. TMT will extend astronomy with extremely large telescopes to all of its global communities.

  18. Liverpool Telescope and Liverpool Telescope 2

    NASA Astrophysics Data System (ADS)

    Copperwheat, C. M.; Steele, I. A.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Jermak, H.; Marchant, J. M.; Mottram, C. J.; Piascik, A.; Smith, R. J.

    2016-12-01

    The Liverpool Telescope is a fully robotic optical/near-infrared telescope with a 2-metre clear aperture, located at the Observatorio del Roque de los Muchachos on the Canary Island of La Palma. The telescope is owned and operated by Liverpool John Moores University, with financial support from the UK's Science and Technology Facilities Council. The telescope began routine science operations in 2004 and is a common-user facility with time available through a variety of committees via an open, peer reviewed process. Seven simultaneously mounted instruments support a broad science programme, with a focus on transient follow-up and other time domain topics well suited to the characteristics of robotic observing. Development has also begun on a successor facility, with the working title `Liverpool Telescope 2', to capitalise on the new era of time domain astronomy which will be brought about by the next generation of survey facilities such as LSST. The fully robotic Liverpool Telescope 2 will have a 4-metre aperture and an improved response time. In this paper we provide an overview of the current status of both facilities.

  19. DISSOLUTION OF PLUTONIUM METAL IN 8-10 M NITRIC ACID

    SciTech Connect

    Rudisill, T. S.; Pierce, R. A.

    2012-07-02

    The H-Canyon facility will be used to dissolve Pu metal for subsequent purification and conversion to plutonium dioxide (PuO{sub 2}) using Phase II of HB-Line. To support the new mission, the development of a Pu metal dissolution flowsheet which utilizes concentrated (8-10 M) nitric acid (HNO{sub 3}) solutions containing potassium fluoride (KF) is required. Dissolution of Pu metal in concentrated HNO{sub 3} is desired to eliminate the need to adjust the solution acidity prior to purification by anion exchange. The preferred flowsheet would use 8-10 M HNO{sub 3}, 0.015-0.07 M KF, and 0.5-1.0 g/L Gd to dissolve the Pu up to 6.75 g/L. An alternate flowsheet would use 8-10 M HNO{sub 3}, 0.05-0.2 M KF, and 1-2 g/L B to dissolve the Pu. The targeted average Pu metal dissolution rate is 20 mg/min-cm{sup 2}, which is sufficient to dissolve a “standard” 2250-g Pu metal button in 24 h. Plutonium metal dissolution rate measurements showed that if Gd is used as the nuclear poison, the optimum dissolution conditions occur in 10 M HNO{sub 3}, 0.04-0.05 M KF, and 0.5-1.0 g/L Gd at 112 to 116 °C (boiling). These conditions will result in an estimated Pu metal dissolution rate of ~11-15 mg/min-cm{sup 2} and will result in dissolution times of 36-48 h for standard buttons. The recommended minimum and maximum KF concentrations are 0.03 M and 0.07 M, respectively. The data also indicate that lower KF concentrations would yield dissolution rates for B comparable to those observed with Gd at the same HNO{sub 3} concentration and dissolution temperature. To confirm that the optimal conditions identified by the dissolution rate measurements can be used to dissolve Pu metal up to 6.75 g/L in the presence of representative concentrations of Fe and Gd or B, a series of experiments was performed to demonstrate the flowsheets. In three of the five experiments, the offgas generation rate during the dissolution was measured and samples were analyzed for hydrogen gas (H{sub 2}). The use of

  20. Deterministic separation of cancer cells from blood at 10 mL/min

    NASA Astrophysics Data System (ADS)

    Loutherback, Kevin; D'Silva, Joseph; Liu, Liyu; Wu, Amy; Austin, Robert H.; Sturm, James C.

    2012-12-01

    Circulating tumor cells (CTCs) and circulating clusters of cancer and stromal cells have been identified in the blood of patients with malignant cancer and can be used as a diagnostic for disease severity, assess the efficacy of different treatment strategies and possibly determine the eventual location of metastatic invasions for possible treatment. There is thus a critical need to isolate, propagate and characterize viable CTCs and clusters of cancer cells with their associated stroma cells. Here, we present a microfluidic device for mL/min flow rate, continuous-flow capture of viable CTCs from blood using deterministic lateral displacement (DLD) arrays. We show here that a DLD array device can isolate CTCs from blood with capture efficiency greater than 85% CTCs at volumetric flow rates of up to 10 mL/min with no effect on cell viability.

  1. Innovative Structural Design Features for a 10 m Solar Sail Demonstrator

    NASA Technical Reports Server (NTRS)

    Laue, G.; Moore, J.; Clayton, W.

    2004-01-01

    The successful development of sail architectures will require careful attention to a number of key issues including but not limited to material strength issues, stress conditions for the membrane, load interactions between membrane and structure, and membrane material planarity. Along with the inherent challenges of fabricating and handling very large membrane structures these issues will pose real challenges for the near-term development of practical sail technologies. SRS has developed innovative technologies that deal directly with the challenges of developing very large sail membranes. Some of these technologies include edge reinforcements and innovative reinforcement attachment techniques, production of flight durable sail materials of less than 2.5 micron thicknesses and large scale fabrication techniques. SRS has employed these technologies in several large 10 m demonstrators that have been delivered to LaRC for solar vacuum testing. Details of the design of this system will be discussed.

  2. CHARACTERIZING THE ORBITAL AND DYNAMICAL STATE OF THE HD 82943 PLANETARY SYSTEM WITH KECK RADIAL VELOCITY DATA

    SciTech Connect

    Tan, Xianyu; Lee, Man Hoi; Payne, Matthew J.; Ford, Eric B.; Howard, Andrew W.; Johnson, John A.; Marcy, Geoff W.; Wright, Jason T.

    2013-11-10

    We present an updated analysis of radial velocity data of the HD 82943 planetary system based on 10 yr of measurements obtained with the Keck telescope. Previous studies have shown that the HD 82943 system has two planets that are likely in 2:1 mean-motion resonance (MMR), with orbital periods about 220 and 440 days. However, alternative fits that are qualitatively different have also been suggested, with two planets in a 1:1 resonance or three planets in a Laplace 4:2:1 resonance. Here we use χ{sup 2} minimization combined with a parameter grid search to investigate the orbital parameters and dynamical states of the qualitatively different types of fits, and we compare the results to those obtained with the differential evolution Markov chain Monte Carlo method. Our results support the coplanar 2:1 MMR configuration for the HD 82943 system, and show no evidence for either the 1:1 or three-planet Laplace resonance fits. The inclination of the system with respect to the sky plane is well constrained at 20{sup +4.9}{sub -5.5} degrees, and the system contains two planets with masses of about 4.78 M{sub J} and 4.80 M{sub J} (where M{sub J} is the mass of Jupiter) and orbital periods of about 219 and 442 days for the inner and outer planet, respectively. The best fit is dynamically stable with both eccentricity-type resonant angles θ{sub 1} and θ{sub 2} librating around 0°.

  3. High-resolution N-band Observations Of The Nova Rs Ophiuchi: First Science With The Keck Interferometer Nuller

    NASA Astrophysics Data System (ADS)

    Barry, Richard K.; Danchi, W. C.; Sokoloski, J. L.; Koresko, C.; Wisniewski, J.; Serabyn, E.; Traub, W.; Kuchner, M.; Greenhouse, M.

    2007-12-01

    We report new observations of the nova RS Ophiuchi using the Keck Interferometer Nulling Instrument (KIN), approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. These observations represent the first scientific results from the KIN, which operates in N-band from 8 to 12.5 microns. The nulling technique is the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture telescopes. By fitting the unique KIN inner and outer spatial regime data, we have obtained an angular size of the mid-infrared continuum of 6.2, 4.0, or 5.4 mas for a disk profile, Gaussian profile, and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf relative to the outer regime. There are also nebular emission lines and evidence of hot silicate dust in the outer spatial region, centered at approximately 2.5E14 cm from the WD, that are not found in the inner regime. The nova flash in the outer spatial regime evidently excited these features before the blast wave reached these regions. These identifications support the following interpretation. The dust appears to be present between outbursts and was not created during the outburst event. We further discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power and potential of the nulling technique which has been developed for the detection of Earth-like planets around nearby stars for the Terrestrial Planet Finder Mission and Darwin missions.

  4. High-Resolution N-Band Observations of the Nova Rs Ophiuchi: First Science with the Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Danchi, William

    2008-01-01

    We report new observations of the nova RS Ophiuchi using the Keck Interferometer Nulling Instrument (KIN), approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. These observations represent the first scientific results from the KIN, which operates in N-band from 8 to 12.5 microns. The nulling technique is the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture telescopes. By fitting the unique KIN inner and outer spatial regime data, we have obtained an angular size of the mid-infrared continuum of 6.2,4.0, or 5.4 mas for a disk profile, Gaussian profile, and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf relative to the outer regime. There are also nebular emission lines and evidence of hot silicate dust in the outer spatial region, centered at approximately 2.5E14 cm from the WD, that are not found in the inner regime. The nova flash in the outer spatial regime evidently excited these features before the blast wave reached these regions. These identifications support the following interpretation. The dust appears to be present between outbursts and was not created during the outburst event. We further discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power and potential of the nulling technique which has been developed for the detection of Earthlike planets around nearby stars for the Terrestrial Planet Finder Mission and Darwin missions.

  5. Milliarcsecond N-Band Observations of the Nova RS Ophiuchi: First Science with the Keck Interferometer Nuller

    NASA Astrophysics Data System (ADS)

    Barry, R. K.; Danchi, W. C.; Traub, W. A.; Sokoloski, J. L.; Wisniewski, J. P.; Serabyn, E.; Kuchner, M. J.; Akeson, R.; Appleby, E.; Bell, J.; Booth, A.; Brandenburg, H.; Colavita, M.; Crawford, S.; Creech-Eakman, M.; Dahl, W.; Felizardo, C.; Garcia, J.; Gathright, J.; Greenhouse, M. A.; Herstein, J.; Hovland, E.; Hrynevych, M.; Koresko, C.; Ligon, R.; Mennesson, B.; Millan-Gabet, R.; Morrison, D.; Palmer, D.; Panteleeva, T.; Ragland, S.; Shao, M.; Smythe, R.; Summers, K.; Swain, M.; Tsubota, K.; Tyau, C.; Wetherell, E.; Wizinowich, P.; Woillez, J.; Vasisht, G.

    2008-04-01

    We report observations of the nova RS Ophiuchi (RS Oph) using the Keck Interferometer Nuller (KIN), approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. These observations represent the first scientific results from the KIN, which operates in N band from 8 to 12.5 μm in a nulling mode. The nulling technique is the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture telescopes. In this mode the stellar light itself is suppressed by a destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. By fitting the unique KIN data, we have obtained an angular size of the mid-infrared continuum emitting material of 6.2, 4.0, or 5.4 mas for a disk profile, Gaussian profile (FWHM), and shell profile, respectively. The data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf (WD) relative to the outer regime. There are also nebular emission lines and evidence of hot silicate dust in the outer spatial region, centered at ~17 AU from the WD, that are not found in the inner regime. Our evidence suggests that these features have been excited by the nova flash in the outer spatial regime before the blast wave reached these regions. These identifications support a model in which the dust appears to be present between outbursts and is not created during the outburst event. We further discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star.

  6. THE RESOLVED STRUCTURE AND DYNAMICS OF AN ISOLATED DWARF GALAXY: A VLT AND KECK SPECTROSCOPIC SURVEY OF WLM

    SciTech Connect

    Leaman, Ryan; Venn, Kim A.; Mendel, J. Trevor; Brooks, Alyson M.; Cole, Andrew A.; Ibata, Rodrigo A.; Irwin, Mike J.; McConnachie, Alan W.; Tolstoy, Eline

    2012-05-01

    We present spectroscopic data for 180 red giant branch (RGB) stars in the isolated dwarf irregular galaxy Wolf-Lundmark-Mellote (WLM). Observations of the calcium II triplet lines in spectra of RGB stars covering the entire galaxy were obtained with FORS2 at the Very Large Telescope and DEIMOS on Keck II, allowing us to derive velocities, metallicities, and ages for the stars. With accompanying photometric and radio data we have measured the structural parameters of the stellar and gaseous populations over the full galaxy. The stellar populations show an intrinsically thick configuration with 0.39 {<=} q{sub 0} {<=} 0.57. The stellar rotation in WLM is measured to be 17 {+-} 1 km s{sup -1}; however, the ratio of rotation to pressure support for the stars is V/{sigma} {approx} 1, in contrast to the gas, whose ratio is seven times larger. This, along with the structural data and alignment of the kinematic and photometric axes, suggests we are viewing WLM as a highly inclined oblate spheroid. Stellar rotation curves, corrected for asymmetric drift, are used to compute a dynamical mass of (4.3 {+-} 0.3) Multiplication-Sign 10{sup 8} M{sub Sun} at the half-light radius (r{sub h} = 1656 {+-} 49 pc). The stellar velocity dispersion increases with stellar age in a manner consistent with giant molecular cloud and substructure interactions producing the heating in WLM. Coupled with WLM's isolation, this suggests that the extended vertical structure of its stellar and gaseous components and increase in stellar velocity dispersion with age are due to internal feedback, rather than tidally driven evolution. These represent some of the first observational results from an isolated Local Group dwarf galaxy that can offer important constraints on how strongly internal feedback and secular processes modulate star formation and dynamical evolution in low-mass isolated objects.

  7. CONTAMINATION OF BROADBAND PHOTOMETRY BY NEBULAR EMISSION IN HIGH-REDSHIFT GALAXIES: INVESTIGATIONS WITH KECK'S MOSFIRE NEAR-INFRARED SPECTROGRAPH

    SciTech Connect

    Schenker, Matthew A; Ellis, Richard S; Konidaris, Nick P; Stark, Daniel P

    2013-11-01

    Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high-redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ≅ 6-7, such lines may be strong enough to reduce estimates of the stellar masses and ages of galaxies compared with those derived assuming the broadband photometry represents stellar light alone. To test this hypothesis at the highest redshifts where such lines can be probed with ground-based facilities, we examine the near-infrared spectra of a representative sample of 28 3.0 < z < 3.8 Lyman break galaxies using the newly commissioned MOSFIRE near-infrared spectrograph at the Keck I telescope. We use these data to derive the rest-frame equivalent widths (EWs) of [O III] emission and show that these are comparable with estimates derived using the spectral energy distribution (SED) fitting technique introduced for sources of known redshift by Stark et al. Although our current sample is modest, its [O III] EW distribution is consistent with that inferred for Hα based on SED fitting of Stark et al.'s larger sample of 3.8 < z < 5 galaxies. For a subset of survey galaxies, we use the combination of optical and near-infrared spectroscopy to quantify kinematics of outflows in z ≅ 3.5 star-forming galaxies and discuss the implications for reionization measurements. The trends we uncover underline the dangers of relying purely on broadband photometry to estimate the physical properties of high-redshift galaxies and emphasize the important role of diagnostic spectroscopy.

  8. Confronting Standard Models of Proto-planetary Disks with New Mid-infrared Sizes from the Keck Interferometer

    NASA Astrophysics Data System (ADS)

    Millan-Gabet, Rafael; Che, Xiao; Monnier, John D.; Sitko, Michael L.; Russell, Ray W.; Grady, Carol A.; Day, Amanda N.; Perry, R. B.; Harries, Tim J.; Aarnio, Alicia N.; Colavita, Mark M.; Wizinowich, Peter L.; Ragland, Sam; Woillez, Julien

    2016-08-01

    We present near- and mid-infrared (MIR) interferometric observations made with the Keck Interferometer Nuller and near-contemporaneous spectro-photometry from the infrared telescope facilities (IRTFs) of 11 well-known young stellar objects, several of which were observed for the first time in these spectral and spatial resolution regimes. With au-level spatial resolution, we first establish characteristic sizes of the infrared emission using a simple geometrical model consisting of a hot inner rim and MIR disk emission. We find a high degree of correlation between the stellar luminosity and the MIR disk sizes after using near-infrared data to remove the contribution from the inner rim. We then use a semi-analytical physical model to also find that the very widely used “star + inner dust rim + flared disk” class of models strongly fails to reproduce the spectral energy distribution (SED) and spatially resolved MIR data simultaneously; specifically a more compact source of MIR emission is required than results from the standard flared disk model. We explore the viability of a modification to the model whereby a second dust rim containing smaller dust grains is added, and find that the 2-rim model leads to significantly improved fits in most cases. This complexity is largely missed when carrying out SED modeling alone, although detailed silicate feature fitting by McClure et al. recently came to a similar conclusion. As has been suggested recently by Menu et al., the difficulty in predicting MIR sizes from the SED alone might hint at “transition disk”-like gaps in the inner au; however, the relatively high correlation found in our MIR disk size versus stellar luminosity relation favors layered disk morphologies and points to missing disk model ingredients instead.

  9. A Spectroscopic Redshift Measurement for a Luminous Lyman Break Galaxy at z = 7.730 Using Keck/MOSFIRE

    NASA Astrophysics Data System (ADS)

    Oesch, P. A.; van Dokkum, P. G.; Illingworth, G. D.; Bouwens, R. J.; Momcheva, I.; Holden, B.; Roberts-Borsani, G. W.; Smit, R.; Franx, M.; Labbé, I.; González, V.; Magee, D.

    2015-05-01

    We present a spectroscopic redshift measurement of a very bright Lyman break galaxy at z=7.7302+/- 0.0006 using the Keck/Multi-Object Spectrometer for Infra-Red Exploration. The source was pre-selected photometrically in the EGS field as a robust z ˜ 8 candidate with H = 25.0 mag based on optical non-detections and a very red Spitzer/IRAC [3.6]-[4.5] broad-band color driven by high equivalent width [O iii]+Hβ line emission. The Lyα line is reliably detected at 6.1σ and shows an asymmetric profile as expected for a galaxy embedded in a relatively neutral intergalactic medium near the Planck peak of cosmic reionization. The line has a rest-frame equivalent width of E{{W}0}=21+/- 4 Å and is extended with {{V}FWHM}=360-70+90 km s-1. The source is perhaps the brightest and most massive z ˜ 8 Lyman break galaxy in the full CANDELS and BoRG/HIPPIES surveys, having already assembled {{10}9.9+/- 0.2} {{M}⊙ } of stars at only 650 Myr after the Big Bang. The spectroscopic redshift measurement sets a new redshift record for galaxies. This enables reliable constraints on the stellar mass, star formation rate, and formation epoch, as well as combined [O iii]+Hβ line equivalent widths. The redshift confirms that the IRAC [4.5] photometry is very likely dominated by line emission with EW0([O iii]+Hβ) = 720-150+180 Å. This detection thus adds to the evidence that extreme rest-frame optical emission lines are a ubiquitous feature of early galaxies promising very efficient spectroscopic follow-up in the future with infrared spectroscopy using the James Webb Space Telescope and, later, ELTs.

  10. Contamination of Broadband Photometry by Nebular Emission in High-redshift Galaxies: Investigations with Keck's MOSFIRE Near-infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Schenker, Matthew A.; Ellis, Richard S.; Konidaris, Nick P.; Stark, Daniel P.

    2013-11-01

    Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high-redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ~= 6-7, such lines may be strong enough to reduce estimates of the stellar masses and ages of galaxies compared with those derived assuming the broadband photometry represents stellar light alone. To test this hypothesis at the highest redshifts where such lines can be probed with ground-based facilities, we examine the near-infrared spectra of a representative sample of 28 3.0 < z < 3.8 Lyman break galaxies using the newly commissioned MOSFIRE near-infrared spectrograph at the Keck I telescope. We use these data to derive the rest-frame equivalent widths (EWs) of [O III] emission and show that these are comparable with estimates derived using the spectral energy distribution (SED) fitting technique introduced for sources of known redshift by Stark et al. Although our current sample is modest, its [O III] EW distribution is consistent with that inferred for Hα based on SED fitting of Stark et al.'s larger sample of 3.8 < z < 5 galaxies. For a subset of survey galaxies, we use the combination of optical and near-infrared spectroscopy to quantify kinematics of outflows in z ~= 3.5 star-forming galaxies and discuss the implications for reionization measurements. The trends we uncover underline the dangers of relying purely on broadband photometry to estimate the physical properties of high-redshift galaxies and emphasize the important role of diagnostic spectroscopy.

  11. KECK/MOSFIRE SPECTROSCOPIC CONFIRMATION OF A VIRGO-LIKE CLUSTER ANCESTOR AT z = 2.095

    SciTech Connect

    Yuan, Tiantian; Kewley, Lisa J.; Nanayakkara, Themiya; Kacprzak, Glenn G.; Glazebrook, Karl; Tran, Kim-Vy H.; Tomczak, Adam R.; Spitler, Lee R.; Poole, Gregory B.; Labbé, Ivo; Straatman, Caroline M. S.

    2014-11-01

    We present spectroscopic confirmation of a galaxy cluster at z = 2.095 in the COSMOS field. This galaxy cluster was first reported in the ZFOURGE survey as harboring evolved massive galaxies using photometric redshifts derived with deep near-infrared (NIR) medium-band filters. We obtain medium-resolution (R ∼ 3600) NIR spectroscopy with MOSFIRE on the Keck 1 telescope and secure 180 redshifts in a 12' × 12' region. We find a prominent spike of 57 galaxies at z = 2.095 corresponding to the galaxy cluster. The cluster velocity dispersion is measured to be σ{sub v1D}  =  552 ± 52 km s{sup –1}. This is the first study of a galaxy cluster in this redshift range (z ≳ 2.0) with the combination of spectral resolution (∼26 km s{sup –1}) and the number of confirmed members (>50) needed to impose a meaningful constraint on the cluster velocity dispersion and map its members over a large field of view. Our ΛCDM cosmological simulation suggests that this cluster will most likely evolve into a Virgo-like cluster with M {sub vir} = 10{sup 14.4} {sup ±} {sup 0.3} M {sub ☉} (68% confidence) at z ∼ 0. The theoretical probability of finding such a cluster is ∼4%. Our results demonstrate the feasibility of studying galaxy clusters at z > 2 in the same detailed manner using multi-object NIR spectrographs as has been done in the optical in lower-redshift clusters.

  12. NIR Imaging Spectroscopy of the Inner Few Arcseconds of NGC 4151 with OSIRIS at Keck

    NASA Technical Reports Server (NTRS)

    Iserlohe, Christof; Krabbe, Alfred; Larkin, James E.; Barczys, Matthew; McElwain, Michael W.; Quirrenbach, Andreas; Weiss, Jason; Wright, Shelley A.

    2013-01-01

    We present H- and K-band data from the inner arcsecond of the Seyfert 1.5 galaxy NGC 4151 obtained with the adaptive optics assisted near-infrared imaging field spectrograph OSIRIS at the Keck Observatory. The angular resolution is about a few parsecs on-site and thus competes easily with optical images taken previously with the Hubble Space Telescope. We present the morphology and dynamics of most species detected but focus on the morphology and dynamics of the narrow line region (as traced by emission of [FeII]?1.644 µm), the interplay between plasma ejected from the nucleus (as traced by 21 cm continuum radio data) and hot H2 gas and characterize the detected nuclear HeI?2.058 µm absorption feature as a narrow absorption line (NAL) phenomenon. Emission from the narrow line region (NLR) as traced by [FeII] reveals a biconical morphology and we compare the measured dynamics in the [FeII] emission line with models proposing acceleration of gas in the NLR and simple ejection of gas into the NLR. In the inner 2.5 arcseconds the acceleration model reveals a better fit to our data than the ejection model.We also see evidence that the jet very locally enhances emission in [FeII] at certain positions in our field-of-view such that we were able to distinct the kinematics of these clouds from clouds generally accelerated in the NLR. Further, the radio jet is aligned with the bicone surface rather than the bicone axis such that we assume that the jet is not the dominant mechanism responsible for driving the kinematics of clouds in the NLR. The hot H2 gas is thermal with a temperature of about 1700 K. We observe a remarkable correlation between individual H2 clouds at systemic velocity with the 21 cm continuum radio jet. We propose that the radio jet is at least partially embedded in the galactic disk of NGC 4151 such that deviations from a linear radio structure are invoked by interactions of jet plasma with H2 clouds that are moving into the path of the jet because of

  13. JWST Pathfinder Telescope Integration

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI&T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  14. The Solar Telescope GREGOR

    NASA Astrophysics Data System (ADS)

    Volkmer, R.

    2008-09-01

    During the last years the new 1.5m solar telescope GREGOR was assembled at Izania on Tenerife, Spain. The telescope is designed for high-precision measurements of the magnetic field in the solar photosphere and chromosphere with a resolution of 70km on the Sun. The telescope concept offers also high resolution stellar spectroscopy. The telescope is build by a consortium of the Kiepenheuer-Institut für Sonnenphysik, the Astrophysikalische Institut Potsdam, the Institut für Astrophysik Göttingen, Max-Plank-Institut für Sonnensystemforschung and additional international Partners. The telescope is a complete open structure with active cooled main mirror. High performance post-focus instruments in the visible and near IR wavelength acquire high resolution spectra with 2 dimensional spatial resolution and polarimetric information. The commissioning of the telescope will start in 2008 to allow first science observations at the end of 2009.

  15. Automated telescope scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1988-01-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  16. Airborne Infrared Astronomical Telescopes

    NASA Astrophysics Data System (ADS)

    Erickson, Edwin F.

    2017-01-01

    A unique program of infrared astronomical observations from aircraft evolved at NASA’s Ames Research Center, beginning in the 1960s. Telescopes were flown on a Convair 990, a Lear Jet, and a Lockheed C-141 - the Kuiper Airborne Observatory (KAO) - leading to the planning and development of SOFIA: a 2.7 m telescope now flying on a Boeing 747SP. The poster describes these telescopes and highlights of some of the scientific results obtained from them.

  17. New telescope designs suitable for massively multiplexed spectroscopy

    NASA Astrophysics Data System (ADS)

    Pasquini, Luca; Delabre, B.; Ellis, R.; de Zeeuw, Tim

    2016-07-01

    We present two novel designs for a telescope suitable for massively-multiplexed spectroscopy. The first is a very wide field Cassegrain telescope optimised for fibre feeding. It provides a Field Of View (FOV) of 2.5 degrees diameter with a 10m primary mirror. It is telecentric and works at F/3, optimal for fibre injection. As an option, a gravity invariant focus for the central 10 arc-minutes can be added, to host, for instance, a giant integral field unit (IFU). It has acceptable performance in the 360-1300 nm wavelength range. The second concept is an innovative five mirror telescope design based on a Three Mirror Anastigmatic (TMA) concept. The design provides a large FOV in a convenient, gravityinvariant focal plane, and is scalable to a range of telescope diameters. As specific example, we present a 10m telescope with a 1.5 degree diameter FOV and a relay system that allows simultaneous spectroscopy with 10,000 mini-IFUs over a square degree, or, alternatively a 17.5 square arcminutes giant IFU, by using 240 MUSE-type spectrographs. We stress the importance of developing the telescope and instrument designs for both cases.

  18. High volume production trial of mirror segments for the Thirty Meter Telescope

    NASA Astrophysics Data System (ADS)

    Oota, Tetsuji; Negishi, Mahito; Shinonaga, Hirohiko; Gomi, Akihiko; Tanaka, Yutaka; Akutsu, Kotaro; Otsuka, Itaru; Mochizuki, Shun; Iye, Masanori; Yamashita, Takuya

    2014-07-01

    The Thirty Meter Telescope is a next-generation optical/infrared telescope to be constructed on Mauna Kea, Hawaii toward the end of this decade, as an international project. Its 30 m primary mirror consists of 492 off-axis aspheric segmented mirrors. High volume production of hundreds of segments has started in 2013 based on the contract between National Astronomical Observatory of Japan and Canon Inc.. This paper describes the achievements of the high volume production trials. The Stressed Mirror Figuring technique which is established by Keck Telescope engineers is arranged and adopted. To measure the segment surface figure, a novel stitching algorithm is evaluated by experiment. The integration procedure is checked with prototype segment.

  19. The 10 Meter South Pole Telescope

    NASA Astrophysics Data System (ADS)

    Carlstrom, J. E.; Ade, P. A. R.; Aird, K. A.; Benson, B. A.; Bleem, L. E.; Busetti, S.; Chang, C. L.; Chauvin, E.; Cho, H.-M.; Crawford, T. M.; Crites, A. T.; Dobbs, M. A.; Halverson, N. W.; Heimsath, S.; Holzapfel, W. L.; Hrubes, J. D.; Joy, M.; Keisler, R.; Lanting, T. M.; Lee, A. T.; Leitch, E. M.; Leong, J.; Lu, W.; Lueker, M.; Luong-Van, D.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mohr, J. J.; Montroy, T. E.; Padin, S.; Plagge, T.; Pryke, C.; Ruhl, J. E.; Schaffer, K. K.; Schwan, D.; Shirokoff, E.; Spieler, H. G.; Staniszewski, Z.; Stark, A. A.; Tucker, C.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2011-05-01

    The South Pole Telescope (SPT) is a 10 m diameter, wide-field, offset Gregorian telescope with a 966 pixel, multicolor, millimeter-wave, bolometer camera. It is located at the Amundsen-Scott South Pole station in Antarctica. The design of the SPT emphasizes careful control of spillover and scattering, to minimize noise and false signals due to ground pickup. The key initial project is a large-area survey at wavelengths of 3, 2, and 1.3 mm, to detect clusters of galaxies via the Sunyaev-Zel’dovich effect and to measure the small-scale angular power spectrum of the cosmic microwave background (CMB). The data will be used to characterize the primordial matter power spectrum and to place constraints on the equation of state of dark energy. A second-generation camera will measure the polarization of the CMB, potentially leading to constraints on the neutrino mass and the energy scale of inflation.

  20. An Examination of Residual Wind Fluctuations Observed at 10 m over Flat Terrain.

    NASA Astrophysics Data System (ADS)

    Leahey, D. M.; Hansen, M. C.; Schroeder, M. B.

    1996-01-01

    This study investigates the behavior of wind fluctuations observed at the 10-m level over a flat terrain site located some 100 km east of the Rocky Mountains. The purposes were to assess residual fluctuations in order to ascertain effects attributable to the nonhomogenous, nonstationary character of turbulence and to evaluate influences of gravity waves. Residual wind fluctuations were defined for purposes of this study as the differences between observed half-hourly average standard deviations of wind fluctuations (v, u, w) and those that are expected to occur in association with simultaneous wind speeds and static stabilities. These latter fluctuations were estimated from equations developed by Leahey, Hansen, and Schroeder (LHS).Results of the analyses showed, as expected, that residual distributions for nonwesterly wind conditions were nearly Gaussian. Standard deviations for residuals of horizontal fluctuations, attributable to the nonhomogenous, nonstationary nature of turbulence, were 0.165 and 0.210 m s1 for stable and unstable situations, respectively. For residuals associated with vertical fluctuations they were, respectively, 0.065 and 0.075 m s1.Residuals for horizontal and vertical wind fluctuations observed when winds were from the mountains showed a greater tendency for the positive bias associated with gravity waves. This tendency was most evident under unstable conditions when gravity wave influences on horizontal fluctuations were apparent about 25% of the time. These influences are explained as being associated with mountain lee waves occurring at the planetary boundary layer's capping inversion. They are evidenced at the 10-m level because atmospheric mixing processes occurring in thermally unstable atmospheric situations bring momentum generated from these waves downward to the ground.Nonstationary and nonhomogenous atmospheric turbulence effects result in wind fluctuations whose half-hourly average standard deviations differ from those

  1. Size-Frequency Distribution of Boulders ≥ 10 m on Comet 103P/Hartley 2

    NASA Astrophysics Data System (ADS)

    Pajola, M.; Lucchetti, A.; A'Hearn, M. F.; Bertini, I.; Marzari, F.; La Forgia, F.; Lazzarin, M.; Naletto, G.; Barbieri, C.

    2015-12-01

    We present the first size-frequency distribution of boulders ≥ 10 m identified on comet 103P/Hartley 2, computed from the images taken by the Deep Impact/High Resolution Imager - Visible CCD camera on 4 November 2010. We derived the size-frequency distribution of the illuminated side of the comet (˜ 50%), as well as identified the power-law indexes characterizing the two lobes of 103P. 332 boulders larger than 10 m were identified on the imaged surface of the comet, with a global number density of nearly 140/km2 and a cumulative size-frequency distribution represented by a power-law with index of -2.7 ± 0.2. The two lobes of 103P show close indexes, i.e. -2.7 ± 0.2 for the bigger lobe (L1) and -2.6 +0.2/-0.5 for the smaller one (L2). Both the similar power-law indexes and the similar maximum boulder sizes derived for the two lobes point towards a similar fracturing/disintegration phenomena of the boulders as well as similar lifting processes that may occur in L1 and L2. Nonetheless, the significative difference in the number of boulders per km2 between the two lobes suggests that the more diffuse H2O sublimation on the bigger lobe produce twice the boulders per km2 with respect to those produced on the small lobe (primary activity CO2 driven). If we compare the boulder distribution of the hyperactive 103P comet with similar studies performed on 67P (67P/Churyumov-Gerasimenko, i.e. the comet studied by Rosetta spacecraft), we derive that 103P shows a lower global power-law index (-2.7 vs -3.6). The size-frequency boulder trend of 103P is somehow closer to the -2.2 value measured on the neck region of 67P, i.e. the most active region of the northern hemisphere of 67P; nevertheless the hyperactivity of 103P works in a very different way than the normal activity of 67P in the neck/Hapi area. In addition to the global differences between the two comets' activities, the absence of cliffs and walls on 103P show a completely different surface geomorphology between

  2. Size-frequency distribution of boulders ≥10 m on comet 103P/Hartley 2

    NASA Astrophysics Data System (ADS)

    Pajola, Maurizio; Lucchetti, Alice; Bertini, Ivano; Marzari, Francesco; A'Hearn, Michael F.; La Forgia, Fiorangela; Lazzarin, Monica; Naletto, Giampiero; Barbieri, Cesare

    2016-01-01

    Aims: We derive the size-frequency distribution of boulders on comet 103P/Hartley 2, which are computed from the images taken by the Deep Impact/HRI-V imaging system. We indicate the possible physical processes that lead to these boulder size distributions. Methods: We used images acquired by the High Resolution Imager-Visible CCD camera on 4 November 2010. Boulders ≥10 m were identified and manually extracted from the datasets with the software ArcGIS. We derived the global size-frequency distribution of the illuminated side of the comet (~50%) and identified the power-law indexes characterizing the two lobes of 103P. The three-pixel sampling detection, together with the shadowing of the surface, enables unequivocally detection of boulders scattered all over the illuminated surface. Results: We identify 332 boulders ≥10 m on the imaged surface of the comet, with a global number density of nearly 140/km2 and a cumulative size-frequency distribution represented by a power law with index of -2.7 ± 0.2. The two lobes of 103P show similar indexes, i.e., -2.7 ± 0.2 for the bigger lobe (called L1) and -2.6+ 0.2/-0.5 for the smaller lobe (called L2). The similar power-law indexes and similar maximum boulder sizes derived for the two lobes both point toward a similar fracturing/disintegration phenomena of the boulders as well as similar lifting processes that may occur in L1 and L2. The difference in the number of boulders per km2 between L1 and L2 suggests that the more diffuse H2O sublimation on L1 produce twice the boulders per km2 with respect to those produced on L2 (primary activity CO2 driven). The 103P comet has a lower global power-law index (-2.7 vs. -3.6) with respect to 67P. The global differences between the two comets' activities, coupled with a completely different surface geomorphology, make 103P hardly comparable to 67P. A shape distribution analysis of boulders ≥30 m performed on 103P suggests that the cometary boulders show more elongated shapes

  3. BICEP2/Keck Array V: Measurements of B-mode Polarization at Degree Angular Scales and 150 GHz by the Keck Array

    NASA Astrophysics Data System (ADS)

    BICEP2 and Keck Array Collaborations; Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Brevik, J. A.; Buder, I.; Bullock, E.; Buza, V.; Connors, J.; Crill, B. P.; Dowell, C. D.; Dvorkin, C.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Halpern, M.; Harrison, S.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Mason, P.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Willmert, J.; Wong, C. L.; Yoon, K. W.

    2015-10-01

    The Keck Array is a system of cosmic microwave background polarimeters, each similar to the Bicep2 experiment. In this paper we report results from the 2012 to 2013 observing seasons, during which the Keck Array consisted of five receivers all operating in the same (150 GHz) frequency band and observing field as Bicep2. We again find an excess of B-mode power over the lensed-ΛCDM expectation of >5σ in the range 30 < ℓ < 150 and confirm that this is not due to systematics using jackknife tests and simulations based on detailed calibration measurements. In map difference and spectral difference tests these new data are shown to be consistent with Bicep2. Finally, we combine the maps from the two experiments to produce final Q and U maps which have a depth of 57 nK deg (3.4 μK arcmin) over an effective area of 400 deg2 for an equivalent survey weight of 250,000 μK-2. The final BB band powers have noise uncertainty a factor of 2.3 times better than the previous results, and a significance of detection of excess power of >6σ.

  4. BICEP2 / Keck Array V: Measurements of B-mode polarization at degree angular scales and 150 GHz by the Keck Array

    DOE PAGES

    Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; ...

    2015-09-29

    Here, the Keck Array is a system of cosmic microwave background polarimeters, each similar to the Bicep2 experiment. In this paper we report results from the 2012 to 2013 observing seasons, during which the Keck Array consisted of five receivers all operating in the same (150 GHz) frequency band and observing field as Bicep2. We again find an excess of B-mode power over the lensed-ΛCDM expectation of >5σ in the range 30 < ℓ < 150 and confirm that this is not due to systematics using jackknife tests and simulations based on detailed calibration measurements. In map difference and spectralmore » difference tests these new data are shown to be consistent with Bicep2. Finally, we combine the maps from the two experiments to produce final Q and U maps which have a depth of 57 nK deg (3.4 μK arcmin) over an effective area of 400 deg2 for an equivalent survey weight of 250,000 μK–2. The final BB band powers have noise uncertainty a factor of 2.3 times better than the previous results, and a significance of detection of excess power of >6σ.« less

  5. BICEP2/KECK ARRAY V: MEASUREMENTS OF B-MODE POLARIZATION AT DEGREE ANGULAR SCALES AND 150 GHz BY THE KECK ARRAY

    SciTech Connect

    Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Crill, B. P.; Filippini, J. P.; Golwala, S. R.; Alexander, K. D.; Bischoff, C. A.; Buder, I.; Buza, V.; Connors, J.; Dvorkin, C.; Barkats, D.; Benton, S. J.; Bullock, E.; Dowell, C. D.; Duband, L.; Fliescher, S.; Collaboration: Keck Array and Bicep2 Collaborations; and others

    2015-10-01

    The Keck Array is a system of cosmic microwave background polarimeters, each similar to the Bicep2 experiment. In this paper we report results from the 2012 to 2013 observing seasons, during which the Keck Array consisted of five receivers all operating in the same (150 GHz) frequency band and observing field as Bicep2. We again find an excess of B-mode power over the lensed-ΛCDM expectation of >5σ in the range 30 < ℓ < 150 and confirm that this is not due to systematics using jackknife tests and simulations based on detailed calibration measurements. In map difference and spectral difference tests these new data are shown to be consistent with Bicep2. Finally, we combine the maps from the two experiments to produce final Q and U maps which have a depth of 57 nK deg (3.4 μK arcmin) over an effective area of 400 deg{sup 2} for an equivalent survey weight of 250,000 μK{sup −2}. The final BB band powers have noise uncertainty a factor of 2.3 times better than the previous results, and a significance of detection of excess power of >6σ.

  6. BICEP2/Keck - Planck joint analysis and prospects for Galactic foreground removal from CMB observations

    NASA Astrophysics Data System (ADS)

    Crill, Brendan

    2015-08-01

    The joint analysis of 150 GHz polarized maps from BICEP2 and Keck Array at 150 GHz with Planck data at 353 GHzallowed the removal of Galactic dust contamination from the measurement of lensed B-modes in the deep (57 nK deg)BICEP2/Keck maps as well as setting an upper limit on the primordial gravitational wave background from inflation. We present this analysis, describe prospects for polarized foreground cleaning of future suborbitalmeasurements of CMB, and additionally describe Planck's measurements of the spatial correlation of polarizedemission from synchrotron and dust at high galactic latitude, which complicates the removal of Galactic foregrounds at the foregroundminimum of 70-100 GHz.

  7. The Keck Interferometer Nuller (KIN): configuration, measurement approach, and first results

    NASA Astrophysics Data System (ADS)

    Serabyn, E.; Appleby, E.; Bell, J.; Booth, A.; Chin, J.; Colavita, M. M.; Crawford, S.; Creech-Eakman, M.; Dahl, W.; Fanson, J.; Garcia, J.; Gathright, J.; Hovland, E.; Hrynevych, M.; Koresko, C.; Ligon, R.; Mennesson, B.; Moore, J.; Palmer, D.; Panteleeva, T.; Paine, C.; Ragland, S.; Reder, L.; Saloga, T.; Smythe, R.; Tyau, C.; Tsubota, K.; Vasisht, G.; Wetherell, E.; Wizinowich, P.; Woillez, J.

    2005-08-01

    The Keck Interferometer Nuller (KIN) will be used to examine nearby stellar systems for the presence of circumstellar exozodiacal emission. A successful pre-ship review was held for the KIN in June 2004, after which the KIN was shipped to the Keck Observatory. The integration of the KIN's many sub-systems on the summit of Mauna Kea, and initial on-sky testing of the system, has occupied the better part of the past year. This paper describes the KIN system-level configuration, from both the hardware and control points of view, as well as the current state of integration of the system and the measurement approach to be used. During the most recent on-sky engineering runs in May and July 2005, all of the sub-systems necessary to measure a narrowband null were installed and operational, and the full nulling measurement cycle was carried out on a star for the first time.

  8. Spatially Resolved Emission of a z~3 Damped Lyman Alpha Galaxy with Keck/OSIRIS IFU

    NASA Astrophysics Data System (ADS)

    Christenson, Holly; Jorgenson, Regina

    2017-01-01

    The damped Lyman alpha (DLA) class of galaxies contains most of the neutral hydrogen gas over cosmic time. Few DLAs have been detected directly, which limits our knowledge of fundamental properties like size and mass. We present Keck/OSIRIS infrared integral field spectroscopy (IFU) observations of a DLA that was first detected in absorption toward a background quasar. Our observations use the Keck Laser Guide Star Adaptive Optics system to reduce the point-spread function of the quasar, making it possible to spatially resolve the DLA emission. We map this emission in O[III] 5007 Å. At redshift z~3, this DLA represents one of the highest redshift DLAs mapped with IFU spectroscopy. We present measurements of the star formation rate, metallicity, and gas mass of the galaxy.This project was supported in part by the NSF REU grant AST-1358980 and by the Nantucket Maria Mitchell Association.

  9. Invited review article: A 10 mK scanning probe microscopy facility.

    PubMed

    Song, Young Jae; Otte, Alexander F; Shvarts, Vladimir; Zhao, Zuyu; Kuk, Young; Blankenship, Steven R; Band, Alan; Hess, Frank M; Stroscio, Joseph A

    2010-12-01

    We describe the design, development and performance of a scanning probe microscopy (SPM) facility operating at a base temperature of 10 mK in magnetic fields up to 15 T. The microscope is cooled by a custom designed, fully ultra-high vacuum (UHV) compatible dilution refrigerator (DR) and is capable of in situ tip and sample exchange. Subpicometer stability at the tip-sample junction is achieved through three independent vibration isolation stages and careful design of the dilution refrigerator. The system can be connected to, or disconnected from, a network of interconnected auxiliary UHV chambers, which include growth chambers for metal and semiconductor samples, a field-ion microscope for tip characterization, and a fully independent additional quick access low temperature scanning tunneling microscope (STM) and atomic force microscope (AFM) system. To characterize the system, we present the cooling performance of the DR, vibrational, tunneling current, and tip-sample displacement noise measurements. In addition, we show the spectral resolution capabilities with tunneling spectroscopy results obtained on an epitaxial graphene sample resolving the quantum Landau levels in a magnetic field, including the sublevels corresponding to the lifting of the electron spin and valley degeneracies.

  10. Deformation twinning in Ni–Mn–Ga micropillars with 10M martensite

    PubMed Central

    Reinhold, M.; Kiener, D.; Knowlton, W. B.; Dehm, G.; Müllner, P.

    2009-01-01

    The maximum actuation frequency of magnetic shape-memory alloys (MSMAs) significantly increases with decreasing size of the transducer making MSMAs interesting candidates for small scale actuator applications. To study the mechanical properties of Ni–Mn–Ga single crystals on small length scales, two single-domain micropillars with dimensions of 10×15×30 μm3 were fabricated from a Ni–Mn–Ga monocrystal using dual beam focused ion beam machining. The pillars were oriented such that the crystallographic c direction was perpendicular to the loading direction. The pillars were compressed to maximum stresses of 350 and 50 MPa, respectively. Atomic force microscopy and magnetic force microscopy were performed prior to fabrication of the pillars and following the deformation experiments. Both micropillars were deformed by twinning as evidenced by the stress-strain curve. For one pillar, a permanent deformation of 3.6% was observed and ac twins (10M martensite) were identified after unloading. For the other pillar, only 0.7% remained upon unloading. No twins were found in this pillar after unloading. The recovery of deformation is discussed in the light of pseudoelastic twinning and twin-substrate interaction. The twinning stress was higher than in similar macroscopic material. However, further studies are needed to substantiate a size effect. PMID:19859577

  11. SAAO small telescopes, capabilities and Challenges

    NASA Astrophysics Data System (ADS)

    Sefako, Ramotholo

    2015-03-01

    The SAAO is at a geographically crucial site in the southern hemisphere between South America and Australasia. SAAO has a long history of involvement in infrared and optical astronomy that dates back almost two hundred years. The observatory expects to continue contributing to astronomical research for many years to come, using its small (0.5m, 0.75m, 1.0m and 1.9m) telescopes and their various instruments (ranging from spectroscopy to polarimetry and high-speed photometry), together with the Southern African Large Telescope (SALT) and other hosted international telescopes. In this paper, I discuss the capabilities and uses of the SAAO small telescopes, and the challenges that threaten astronomical research at the observatory, including light pollution and other emerging threats to the usually dust-free and dark-night-sky site at Sutherland. This is mitigated by the legislation called the Astronomy Geographic Advantage (AGA) Act of 2007 that protects the observatory from these threats.

  12. New Hubble Space Telescope Observations of Heavy Elements in Four Metal-Poor Stars

    NASA Astrophysics Data System (ADS)

    Roederer, Ian U.; Lawler, James E.; Sobeck, Jennifer S.; Beers, Timothy C.; Cowan, John J.; Frebel, Anna; Ivans, Inese I.; Schatz, Hendrik; Sneden, Christopher; Thompson, Ian B.

    2012-12-01

    Elements heavier than the iron group are found in nearly all halo stars. A substantial number of these elements, key to understanding neutron-capture nucleosynthesis mechanisms, can only be detected in the near-ultraviolet. We report the results of an observing campaign using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope to study the detailed heavy-element abundance patterns in four metal-poor stars. We derive abundances or upper limits from 27 absorption lines of 15 elements produced by neutron-capture reactions, including seven elements (germanium, cadmium, tellurium, lutetium, osmium, platinum, and gold) that can only be detected in the near-ultraviolet. We also examine 202 heavy-element absorption lines in ground-based optical spectra obtained with the Magellan Inamori Kyocera Echelle Spectrograph on the Magellan-Clay Telescope at Las Campanas Observatory and the High Resolution Echelle Spectrometer on the Keck I Telescope on Mauna Kea. We have detected up to 34 elements heavier than zinc. The bulk of the heavy elements in these four stars are produced by r-process nucleosynthesis. These observations affirm earlier results suggesting that the tellurium found in metal-poor halo stars with moderate amounts of r-process material scales with the rare earth and third r-process peak elements. Cadmium often follows the abundances of the neighboring elements palladium and silver. We identify several sources of systematic uncertainty that must be considered when comparing these abundances with theoretical predictions. We also present new isotope shift and hyperfine structure component patterns for Lu II and Pb I lines of astrophysical interest. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 8111 and

  13. High resolution telescope

    DOEpatents

    Massie, Norbert A.; Oster, Yale

    1992-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activites. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes.

  14. Video Telescope Operating Microscopy.

    PubMed

    Divers, Stephen J

    2015-09-01

    Exotic pet veterinarians frequently have to operate on small animals, and magnification is commonly used. Existing endoscopy equipment can be used with a mechanical arm and telescope to enable video telescope operating microscopy. The additional equipment items and their specifics are described, and several case examples are provided.

  15. Goddard Robotic Telescope

    SciTech Connect

    Sakamoto, Takanori; Donato, Davide; Gehrels, Neil; Okajima, Takashi; Ukwatta, Tilan N.

    2009-05-25

    We are constructing the 14'' fully automated optical robotic telescope, Goddard Robotic Telescope (GRT), at the Goddard Geophysical and Astronomical Observatory. The aims of our robotic telescope are 1) to follow-up the Swift/Fermi Gamma-Ray Bursts (GRBs) and 2) to perform the coordinated optical observations of the Fermi/Large Area Telescope (LAT) Active Galactic Nuclei (AGN). Our telescope system consists of the 14'' Celestron Optical Telescope Assembly (OTA), the Astro-Physics 1200GTO mount, the Apogee U47 CCD camera, the JMI's electronic focuser, and the Finger Lake Instrumentation's color filter wheel with U, B, V, R and I filters. With the focal reducer, 20'x20' field of view has been achieved. The observatory dome is the Astro Haven's 7 ft clam-shell dome. We started the scientific observations on mid-November 2008. While not observing our primary targets (GRBs and AGNs), we are planning to open our telescope time to the public for having a wider use of our telescope in both a different research field and an educational purpose.

  16. Analytical study of diffraction effects in extremely large segmented telescopes.

    PubMed

    Yaitskova, Natalia; Dohlen, Kjetil; Dierickx, Philippe

    2003-08-01

    We present an analysis of the diffraction effects from a segmented aperture with a very large number of segments-prototype of the next generation of extremely large telescopes. This analysis is based on the point-spread-function analytical calculation for Keck-type hexagonal segmentation geometry. We concentrate on the effects that lead to the appearance of speckles and/or a regular pattern of diffraction peaks. These effects are related to random piston and tip-tilt errors on each segment, gaps between segments, and segment edge distortion. We deliver formulas and the typical numerical values for the Strehl ratio, the relative intensity of higher-order diffraction peaks, and the averaged intensity of speckles associated with each particular case of segmentation error.

  17. The solar optical telescope

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Objectives of the Solar Optical Telescope are to study the physics of the Sun on the scale at which many of the important physical processes occur and to attain a resolution of 73km on the Sun or 0.1 arc seconds of angular resolution. Topics discussed in this overview of the Solar Optical Telescope include: why is the Solar Optical Telescope needed; current picture of the Sun's atmosphere and convection zone; scientific problems for the Solar Optical Telescope; a description of the telescope; the facility - science management, contamination control, and accessibility to the instruments; the scientific instruments - a coordinated instrument package for unlocking the Sun's secrets; parameters of the coordinated instrument package; science operations from the Space Shuttle; and the dynamic solar atmosphere.

  18. Networked Automatic Optical Telescopes

    NASA Astrophysics Data System (ADS)

    Mattox, J. R.

    2000-05-01

    Many groups around the world are developing automated or robotic optical observatories. The coordinated operation of automated optical telescopes at diverse sites could provide observing prospects which are not otherwise available, e.g., continuous optical photometry without diurnal interruption. Computer control and scheduling also offers the prospect of effective response to transient events such as γ -ray bursts. These telescopes could also serve science education by providing high-quality CCD data for educators and students. The Automatic Telescope Network (ATN) project has been undertaken to promote networking of automated telescopes. A web site is maintained at http://gamma.bu.edu/atn/. The development of such networks will be facilitated by the existence of standards. A set of standard commands for instrument and telescope control systems will allow for the creation of software for an ``observatory control system'' which can be used at any facility which complies with the TCS and ICS standards. Also, there is a strong need for standards for the specification of observations to be done, and reports on the results and status of observations. A proposed standard for this is the Remote Telescope Markup Language (RTML), which is expected to be described in another poster in this session. It may thus be feasible for amateur-astronomers to soon buy all necessary equipment and software to field an automatic telescope. The owner/operator could make otherwise unused telescope time available to the network in exchange for the utilization of other telescopes in the network --- including occasional utilization of meter-class telescopes with research-grade CCD detectors at good sites.

  19. Thermal and Wind Effects on the Azimuth Axis Tilt of the ASTE 10-m Antenna

    NASA Astrophysics Data System (ADS)

    Ukita, Nobuharu; Ezawa, Hajime; Ikenoue, Bungo; Saito, Masao

    2007-10-01

    The azimuth axis tilt of the ASTE 10-m antenna induced by thermal and wind loadings was investigated with a dual-axis inclinometer on the azimuth axis, along with thermometers on the pedestal and yoke structures and an ultrasonic anemometer on a nearby weather station. The dependences of the inclinometer zero-point offsets against temperature of the device, temperature gradients in the pedestal and yoke structure were obtained for the measurements over 11 months during the antenna being parked at its home position (azimuth angles = ?180 degrees, an elevation angle = 60 degrees) under wind velocities < 8 m s-1. The temperature dependences of the zero-point offsets were found to be 1.24 and -0.46 arcseconds/degree, and were close to those obtained with an independent method. The azimuth axis tilts due to the temperature difference between the two opposite sides of pedestal walls were found to be about 1.1 and 1.7 arcseconds/degree, and consistent with 1.5 arcseconds/degree estimated with a simple model. The residual axis tilt of the whole samples after removal of the temperature dependences shows dependence against overturning moment estimated from the wind data. The stiffness of the antenna structures between the yoke base section and the ground was estimated to be 5.3 and 3.4 GNm/rad using the observed tilts in two directions; and were smaller than 6.0 GNm/rad from a mechanical model prediction. Based on these field experiments, we discuss the improvements and limitations of pointing performance with the inclinometer metrology system.

  20. Two Easily Made Astronomical Telescopes.

    ERIC Educational Resources Information Center

    Hill, M.; Jacobs, D. J.

    1991-01-01

    The directions and diagrams for making a reflecting telescope and a refracting telescope are presented. These telescopes can be made by students out of plumbing parts and easily obtainable, inexpensive, optical components. (KR)

  1. The large binocular telescope.

    PubMed

    Hill, John M

    2010-06-01

    The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010.

  2. The GREGOR Solar Telescope

    NASA Astrophysics Data System (ADS)

    Denker, C.; Lagg, A.; Puschmann, K. G.; Schmidt, D.; Schmidt, W.; Sobotka, M.; Soltau, D.; Strassmeier, K. G.; Volkmer, R.; von der Luehe, O.; Solanki, S. K.; Balthasar, H.; Bello Gonzalez, N.; Berkefeld, T.; Collados Vera, M.; Hofmann, A.; Kneer, F.

    2012-12-01

    The 1.5-meter GREGOR solar telescope is a new facility for high-resolution observations of the Sun. The telescope is located at the Spanish Observatorio del Teide on Tenerife. The telescope incorporates advanced designs for a foldable-tent dome, an open steel-truss telescope structure, and active and passive means to minimize telescope and mirror seeing. Solar fine structure can be observed with a dedicated suite of instruments: a broad-band imaging system, the "GREGOR Fabry-Perot Interferometer", and the "Grating Infrared Spectrograph". All post-focus instruments benefit from a high-order (multi-conjugate) adaptive optics system, which enables observations close to the diffraction limit of the telescope. The inclusion of a spectrograph for stellar activity studies and the search for solar twins expands the scientific usage of the GREGOR to the nighttime domain. We report on the successful commissioning of the telescope until the end of 2011 and the first steps towards science verification in 2012.

  3. Gemini telescope structure design

    NASA Astrophysics Data System (ADS)

    Raybould, Keith; Gillett, Paul E.; Hatton, Peter; Pentland, Gordon; Sheehan, Mike; Warner, Mark

    1994-06-01

    The Gemini project is an international collaboration to design, fabricate, and assemble two 8 M telescopes, one on Mauna Kea in Hawaii, the other on Cerro Pachon in Chile. The telescopes will be national facilities designed to meet the Gemini Science Requirements (GSR), a document developed by the Gemini Science Committee (GSC) and the national project scientists. The Gemini telescope group, based on Tucson, has developed a telescope structure to meet the GSR. This paper describes the science requirements that have technically driven the design, and the features that have been incorporated to meet these requirements. This is followed by a brief description of the telescope design. Finally, analyses that have been performed and development programs that have been undertaken are described briefly. Only the designs that have been performed by the Gemini Telescope Structure, Building and Enclosure Group are presented here; control, optical systems, acquisition and guiding, active and adaptive optics, Cassegrain rotator and instrumentation issues are designed and managed by others and will not be discussed here, except for a brief description of the telescope configurations to aid subsequent discussions.

  4. Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    1990-01-01

    An overview of the mission of the Hubble Space Telescope, a joint project between NASA and the European Space Agency which will be used to study deep space, as well as our solar system is presented. The video contains animations depicting the Hubble Space Telescope in orbit, as well as footage of scientists at the Space Telescope Science Institute making real time observations. The images Hubble acquires will be downloaded into a database that contains images of over 19,000,000 celestial objects called the Star Catalog.

  5. Telescopic vision contact lens

    NASA Astrophysics Data System (ADS)

    Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

    2011-03-01

    We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

  6. Multi-use lunar telescopes

    NASA Technical Reports Server (NTRS)

    Drummond, Mark; Hine, Butler; Genet, Russell; Genet, David; Talent, David; Boyd, Louis; Trueblood, Mark; Filippenko, Alexei V. (Editor)

    1991-01-01

    The objective of multi-use telescopes is to reduce the initial and operational costs of space telescopes to the point where a fair number of telescopes, a dozen or so, would be affordable. The basic approach is to develop a common telescope, control system, and power and communications subsystem that can be used with a wide variety of instrument payloads, i.e., imaging CCD cameras, photometers, spectrographs, etc. By having such a multi-use and multi-user telescope, a common practice for earth-based telescopes, development cost can be shared across many telescopes, and the telescopes can be produced in economical batches.

  7. Multi-use lunar telescopes

    NASA Technical Reports Server (NTRS)

    Genet, Russell M.; Genet, David R.; Talent, David L.; Drummond, Mark; Hine, Butler P.; Boyd, Louis J.; Trueblood, Mark

    1992-01-01

    The objective of multi-use telescopes is to reduce the initial and operational costs of space telescopes to the point where a fair number of telescopes, a dozen or so, would be affordable. The basic approach is to develop a common telescope, control system, and power and communications subsystem that can be used with a wide variety of instrument payloads, i.e., imaging CCD cameras, photometers, spectrographs, etc. By having such a multi-use and multi-user telescope, a common practice for earth-based telescopes, development cost can be shared across many telescopes, and the telescopes can be produced in economical batches.

  8. ESO Telescope Designer Raymond Wilson Wins Prestigious Kavli Award for Astrophysics

    NASA Astrophysics Data System (ADS)

    2010-06-01

    with four individual telescopes with 17.5 cm thick 8.2-metre mirrors. Active optics has contributed towards making the VLT the world's most successful ground-based observatory and will be an integral part of ESO's European Extremely Large Telescope (E-ELT) project. Active optics technology is also part of the twin 10-metre Keck telescopes, the Subaru telescope's 8.2-metre mirror and the two 8.1-metre Gemini telescopes. Co-prize winners Jerry Nelson and Roger Angel respectively pioneered the use of segmentation in telescope primary mirrors - as used on the Keck telescopes, and the development of lightweight mirrors with short focal ratios. A webcast from Oslo, Norway, announcing the prize winners is available at www.kavlifoundation.org and www.kavliprize.no. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

  9. Numerical simulation of ground-based telescope enclosures

    NASA Astrophysics Data System (ADS)

    Pan, Nian; Ma, Wenli; Huang, Jinlong

    2014-11-01

    In order to choose enclosure for the next generation telescopes, numerical simulation method was used. Firstly, the telescope, two general kinds of enclosures structure and the external flow field model were established, Then CFD(Computational Fluid Dynamics) technology was used to analyze the wind speed, static pressure, turbulence kinetic energy distribution and eddy around the telescope, when the telescope at two different pointing gestures and the external wind speed at 10m/s. The simulation results showed that when the telescope adapt the retractable enclosure, the wind speed of the main optical path between 6.1 m/s and 9.3 m/s, and the average static pressure (gauge pressure) on the primary mirror between 42.9268 Pa and 37.5579 Pa, however when telescope adapt the hemispherical enclosure, the wind speed of the main optical path between 3.4 m/s and 6.8 m/s, the average static pressure (gauge pressure) on the primary mirror between 12.1387 Pa and 11.105 Pa. Although the wind resistance of the retractable enclosure was lower than the hemispherical enclosure, no eddy generated near the main optical path, it provided the telescope a uniform flow field and ensured the quality of the image of a star. So the retractable enclosure would have better performance than the hemispherical enclosure.

  10. Design and performance of the Douglas Mawson telescope

    NASA Astrophysics Data System (ADS)

    Lawrence, Jon S.; Ashley, Michael C. B.; Burton, Michael G.; Storey, John W. V.

    2002-12-01

    The Douglas Mawson Telescope (DMT) is a proposed 2 m telescope to be situated on the Antarctic plateau. The proposal comes from Australia, and invites participation by other nations, especially those already active in Antarctic astronomy; such as Italy, France and the United States. The DMT will be equipped with instrumentation to perform wide-field imaging from the near to far infrared. Results from an extensive site testing campaign over the last decade indicates that an Antarctic infrared telescope can be one to two orders of magnitude more sensitive than any other ground based telescope of the same size. The DMT will be an important tool for astrophysical research. It will also be beneficial as a technological test bed for future large (8-10 m class) Antarctic telescopes and interferometers, and for space-based telescopes. This paper analyses the performance of the DMT in terms of the achievable resolution, field-of-view, sensitivity and survey depth and compares it to a similar sized telescope located with the characteristic mid-latitude atmosphere of Mauna Kea.

  11. Webb Telescope: Planetary Evolution

    NASA Video Gallery

    Stars and planets form in the dark, inside vast, cold clouds of gas and dust. The James Webb Space Telescope's large mirror and infrared sensitivity will let astronomers peer inside dusty knots whe...

  12. Holographic telescope arrays.

    PubMed

    Lohmann, A W; Sauer, F

    1988-07-15

    A typical job in optical computing is to illuminate an array of small nonlinear optical components, separated by wide gaps to avoid crosstalk. We do this by letting a wide uniform beam fall onto a densely packed array of minifying telescopes. Each telescope produces a narrow bundle of parallel rays which illuminates one of the nonlinear optical components. The holographic telescopes can do more than change the width of the bundles of parallel rays. Their image forming capability allows the transmission of many pixels per channel in parallel. The pair of lenslets of a single holographic telescope (Kepler or Galilean) is produced in rigid coupling. The monolithic production avoids adjusting the two lenslets later on.

  13. Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Mather, John; Stockman, H. S.; Fisher, Richard R. (Technical Monitor)

    2000-01-01

    The Next Generation Space Telescope (NGST), planned for launch in 2009, will be an 8-m class radiatively cooled infrared telescope at the Lagrange point L2. It will cover the wavelength range from 0.6 to 28 microns with cameras and spectrometers, to observe the first luminous objects after the Big Bang, and the formation, growth, clustering, and evolution of galaxies, stars, and protoplanetary clouds, leading to better understanding of our own Origins. It will seek evidence of the cosmic dark matter through its gravitational effects. With an aperture three times greater than the Hubble Space Telescope, it will provide extraordinary advances in capabilities and enable the discovery of many new phenomena. It is a joint project of the NASA, ESA, and CSA, and scientific operations will be provided by the Space Telescope Science Institute.

  14. Telescopes and space exploration

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Maran, S. P.

    1982-01-01

    Progress in contemporary astronomy and astrophysics is shown to depend on complementary investigations with sensitive telescopes operating in several wavelength regions, some of which can be on the Earth's surface and others of which must be in space.

  15. Hubble Space Telescope Assembly

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This photograph shows the Hubble Space Telescope (HST) flight article assembly with multilayer insulation, high gain anterna, and solar arrays in a clean room of the Lockheed Missile and Space Company. The HST is the first of NASA's great observatories and the most complex and sensitive optical telescope ever made. The purpose of the HST is to study the cosmos from a low-Earth orbit by placing the telescope in space, enabling astronomers to collect data that is free of the Earth's atmosphere. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had overall responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company, Sunnyvale, California, produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  16. Composite Space Telescope Truss

    NASA Video Gallery

    NASA engineers are recycling an idea for a lightweight, compact space telescope structure from the early 1990s. The 315 struts and 84 nodes were originally designed to enable spacewalking astronaut...

  17. New catadioptric telescope

    NASA Astrophysics Data System (ADS)

    Richter, J. L.

    1981-01-01

    The Acme telescope is a compound telescope that resembles the familiar Cassegrain type except that the main mirror is spherical and the secondary is an achromatic doublet mangin mirror. Three 6-in. aperture f/15 telescope designs are described. With a cemented, all spherical surface achromangin mirror, there is a small amount of coma which can be eliminated by redesigning with an air space between the crown and flint elements of the achromangin mirror, or by cementing them with one of the concave external surfaces of achromangin figured to an hyperboloid. In the examples, the spherical aberration is nil and the chromatic residual is roughly half that of an achromatic objective of the same speed, aperture, and glass types. Readily available crown and flint glasses such as Schott BK-7 and F-2 are entirely satisfactory for the achromangin mirror. Also considered are two examples of Acme-like telescopes with paraboloidal instead of spherical main mirrors.

  18. Large Binocular Telescope Project

    NASA Astrophysics Data System (ADS)

    Hill, John M.

    1997-03-01

    The large binocular telescope (LBT) project have evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 by 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson, Arizona. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train -- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in the fall of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximum flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1996 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson), EIE and ADS Italia

  19. A Keck/DEIMOS spectroscopic survey of the faint M31 satellites AndIX, AndXI, AndXII and AndXIII†

    NASA Astrophysics Data System (ADS)

    Collins, M. L. M.; Chapman, S. C.; Irwin, M. J.; Martin, N. F.; Ibata, R. A.; Zucker, D. B.; Blain, A.; Ferguson, A. M. N.; Lewis, G. F.; McConnachie, A. W.; Peñarrubia, J.

    2010-10-01

    We present the first spectroscopic analysis of the faint M31 satellite galaxies, AndXI and AndXIII, as well as a re-analysis of existing spectroscopic data for two further faint companions, AndIX (correcting for an error in earlier geometric modelling that caused a misclassification of member stars in previous work) and AndXII. By combining data obtained using the Deep Imaging Multi-Object Spectrograph (DEIMOS) mounted on the Keck II telescope with deep photometry from the Suprime-Cam instrument on Subaru, we have identified the most probable members for each of the satellites based on their radial velocities (precise to several down to i ~ 22), distance from the centre of the dwarf spheroidal galaxies (dSphs) and their photometric [Fe/H]. Using both the photometric and spectroscopic data, we have also calculated global properties for the dwarfs, such as systemic velocities, metallicities and half-light radii. We find each dwarf to be very metal poor ([Fe/H] ~ -2 both photometrically and spectroscopically, from their stacked spectrum), and as such, they continue to follow the luminosity-metallicity relationship established with brighter dwarfs. We are unable to resolve dispersion for AndXI due to small sample size and low signal-to-noise ratio, but we set a 1σ upper limit of σv < 4.5kms-1. For AndIX, AndXII and AndXIII we resolve velocity dispersions of σv = 4.5+3.6-3.4, 2.6+5.1-2.6 and 9.7+8.9-4.5kms-1, though we note that the dispersion for AndXIII is based on just three stars. We derive masses within the half-light radii for these galaxies of 6.2+5.3-5.1 × 106, 2.4+6.5-2.4 × 106 and 1.1+1.4-0.7 × 107Msolar, respectively. We discuss each satellite in the context of the Mateo relations for dSphs, and in reference to the universal halo profiles established for Milky Way dwarfs. Both AndIX and AndXII fall below the universal halo profiles of Walker et al., indicating that they are less massive than would be expected for objects of their half-light radius. When

  20. Resolving Gas Flows in the Ultraluminous Starburst IRAS 23365+3604 with Keck LGSAO/OSIRIS

    NASA Astrophysics Data System (ADS)

    Martin, Crystal L.; Soto, Kurt T.

    2016-03-01

    Keck OSIRIS/LGSAO observations of the ultraluminous galaxy IRAS 23365+3604 resolve a circumnuclear bar (or irregular disk) of semimajor axis 0.″42 (520 pc) in Paα emission. The line-of-sight velocity of the ionized gas increases from the northeast toward the southwest; this gradient is perpendicular to the photometric major axis of the infrared emission. Two pairs of bends in the zero-velocity line are detected. The inner bend provides evidence for gas inflow onto the circumnuclear disk/bar structure. We interpret the gas kinematics on kiloparsec scales in relation to the molecular gas disk and multiphase outflow discovered previously. In particular, the fast component of the ouflow (detected previously in line wings) is not detected, adding support to the conjecture that the fast wind originates well beyond the nucleus. These data directly show the dynamics of gas inflow and outflow in the central kiloparsec of a late-stage, gas-rich merger and demonstrate the potential of integral field spectroscopy to improve our understanding of the role of gas flows during the growth phase of bulges and supermassive black holes. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The data were obtained with the OH Supressing Infrared Spectrograph (OSIRIS) behind the Laser Guide Star Adaptive Optics System.

  1. WAVELENGTH ACCURACY OF THE KECK HIRES SPECTROGRAPH AND MEASURING CHANGES IN THE FINE STRUCTURE CONSTANT

    SciTech Connect

    Griest, Kim; Whitmore, Jonathan B.; Wolfe, Arthur M.; Prochaska, J. Xavier; Howk, J. Christopher; Marcy, Geoffrey W. E-mail: jonathan.b.whitmore@gmail.co

    2010-01-01

    We report on an attempt to accurately wavelength calibrate four nights of data taken with the Keck HIRES spectrograph on QSO PHL957, for the purpose of determining whether the fine structure constant was different in the past. Using new software and techniques, we measured the redshifts of various Ni II, Fe II, Si II, etc. lines in a damped Lyalpha system at z = 2.309. Roughly half the data were taken through the Keck iodine cell which contains thousands of well calibrated iodine lines. Using these iodine exposures to calibrate the normal Th-Ar Keck data pipeline output, we found absolute wavelength offsets of 500 m s{sup -1} to 1000 m s{sup -1} with drifts of more than 500 m s{sup -1} over a single night, and drifts of nearly 2000 m s{sup -1} over several nights. These offsets correspond to an absolute redshift of uncertainty of about DELTAz approx 10{sup -5}(DELTAlambda approx 0.02 A), with daily drifts of around DELTAz approx 5 x 10{sup -6} (DELTAlambda approx 0.01 A), and multiday drifts of nearly DELTAz approx 2 x 10{sup -5}(approx0.04 A). The causes of the wavelength offsets are not known, but since claimed shifts in the fine structure constant would result in velocity shifts of less than 100 m s{sup -1}, this level of systematic uncertainty may make it difficult to use Keck HIRES data to constrain the change in the fine structure constant. Using our calibrated data, we applied both our own fitting software and standard fitting software to measure DELTAalpha/alpha, but discovered that we could obtain results ranging from significant detection of either sign, to strong null limits, depending upon which sets of lines and which fitting method were used. We thus speculate that the discrepant results on DELTAalpha/alpha reported in the literature may be due to random fluctuations coming from underestimated systematic errors in wavelength calibration and fitting procedure.

  2. The Multiple-Mirror Telescope

    ERIC Educational Resources Information Center

    Carleton, Nathaniel P.; Hoffmann, William F.

    1978-01-01

    Describes the basic design and principle of operating an optical-infrared telescope, the MMT. This third largest telescope in the world represents a new stage in telescope design; it uses a cluster of six reflecting telescopes, and relies on an automatic sensing and control system. (GA)

  3. A Newly Developed Fluorescence Model for C2H6 v5 and Application to Cometary Spectra Acquired with NIRSPEC at Keck II

    NASA Technical Reports Server (NTRS)

    Radeva, Yana L.; Mumma, Michael J.; Villanueva, Geronimo L.; A?Hearn, Michael F.

    2011-01-01

    Accurate rotational temperatures are essential for extracting production rates for parent volatiles in comets. Two strong bands of ethane (v7 at 2985.39/cm and v5 at 2895.67/cm) are seen in infrared cometary spectra, but the Q-branches of v7 are not resolved by current instruments and cannot provide an accurate rotational temperature with current models.We developed a fluorescence model for the C2H6 v5 band that can be used to derive a rotational temperature.We applied our C2H6 5 model to high-resolution infrared spectra of the comets C/2004 Q2 Machholz and C/2000 WM1 (LINEAR), acquired with the Near-infrared Echelle Spectrograph on the Keck II telescope. We demonstrate agreement among the rotational temperatures derived from C2H6 v5 and other species, and between mixing ratios derived from C2H6 v5 and C2H6 v7. As a symmetric hydrocarbon, C2H6 is observed only in the infrared, and it is now the fifth molecule (along with H2O, HCN, CO, and H2CO) for which we can derive a reliable rotational temperature from cometary infrared spectra.

  4. A Newly Developed Fluorescence Model for C2H6 ν5 and Application to Cometary Spectra Acquired with NIRSPEC at Keck II

    NASA Astrophysics Data System (ADS)

    Radeva, Yana L.; Mumma, Michael J.; Villanueva, Geronimo L.; A'Hearn, Michael F.

    2011-03-01

    Accurate rotational temperatures are essential for extracting production rates for parent volatiles in comets. Two strong bands of ethane (ν7 at 2985.39 cm-1 and ν5 at 2895.67 cm-1) are seen in infrared cometary spectra, but the Q-branches of ν7 are not resolved by current instruments and cannot provide an accurate rotational temperature with current models. We developed a fluorescence model for the C2H6 ν5 band that can be used to derive a rotational temperature. We applied our C2H6 ν5 model to high-resolution infrared spectra of the comets C/2004 Q2 Machholz and C/2000 WM1 (LINEAR), acquired with the Near-infrared Echelle Spectrograph on the Keck II telescope. We demonstrate agreement among the rotational temperatures derived from C2H6 ν5 and other species, and between mixing ratios derived from C2H6 ν5 and C2H6 ν7. As a symmetric hydrocarbon, C2H6 is observed only in the infrared, and it is now the fifth molecule (along with H2O, HCN, CO, and H2CO) for which we can derive a reliable rotational temperature from cometary infrared spectra.

  5. Telescopes in education

    NASA Astrophysics Data System (ADS)

    Yessayian, Rick

    Imagine sitting in your classroom with your students and controlling a Research Grade 24 inch telescope. You control where it points, you control the duration of the exposure of a high grade CCD camera, and you control all of this within your school day, on a camera half way around the globe, in real time. You can hear the telescope moving, talk to the operator sitting atop historic Mt. Wilson Observatory in California. You might be looking at comets, asteroids, galaxies, nebulas or a host of other interesting celestial objects. Perhaps you have students that are up to a real challenge -- doing real science! Students in our program have contributed the discovery of a new variable star, to the Pluto Express project, to the search for supernovas, and the collection of images of intersecting galaxies. These are among the many possible projects you might choose from. The age and ability of your students are taken into account when you choose your project. Students from Kindergarten through Grade 12 have participated in this free program. A new robotic telescope was added at Mount Wilson in 1999. The telescope is a Celestron 14" SCT mounted on a Bisque Paramount GT-1100 with an Apogee AP-7 CCD camera (512X512 pixels). In the Spring of 2001, we duplicated the 14" robotic telescope configuration and placed it at the Las Campanas Observatory, Chile (operated by the Carnegie Observatories). I installed the system in late September, 2001, and we began testing. The system requires one more upgrade and some hardware adjustments, which I will complete in June, 2002. We duplicated another 14" robotic telescope, and sent it to Brisbane Australia in January, 2002. The grand opening of the telescope will be in August 2002.

  6. Monolithic afocal telescope

    NASA Technical Reports Server (NTRS)

    Roberts, William T. (Inventor)

    2010-01-01

    An afocal monolithic optical element formed of a shallow cylinder of optical material (glass, polymer, etc.) with fast aspheric surfaces, nominally confocal paraboloids, configured on the front and back surfaces. The front surface is substantially planar, and this lends itself to deposition of multi-layer stacks of thin dielectric and metal films to create a filter for rejecting out-of-band light. However, an aspheric section (for example, a paraboloid) can either be ground into a small area of this surface (for a Cassegrain-type telescope) or attached to the planar surface (for a Gregorian-type telescope). This aspheric section of the surface is then silvered to create the telescope's secondary mirror. The rear surface of the cylinder is figured into a steep, convex asphere (again, a paraboloid in the examples), and also made reflective to form the telescope's primary mirror. A small section of the rear surface (approximately the size of the secondary obscuration, depending on the required field of the telescope) is ground flat to provide an unpowered surface through which the collimated light beam can exit the optical element. This portion of the rear surface is made to transmit the light concentrated by the reflective surfaces, and can support the deposition of a spectral filter.

  7. Spectroradiometry with space telescopes

    NASA Astrophysics Data System (ADS)

    Pauluhn, Anuschka; Huber, Martin C. E.; Smith, Peter L.; Colina, Luis

    2015-12-01

    Radiometry, i.e. measuring the power of electromagnetic radiation—hitherto often referred to as "photometry"—is of fundamental importance in astronomy. We provide an overview of how to achieve a valid laboratory calibration of space telescopes and discuss ways to reliably extend this calibration to the spectroscopic telescope's performance in space. A lot of effort has been, and still is going into radiometric "calibration" of telescopes once they are in space; these methods use celestial primary and transfer standards and are based in part on stellar models. The history of the calibration of the Hubble Space Telescope serves as a platform to review these methods. However, we insist that a true calibration of spectroscopic space telescopes must directly be based on and traceable to laboratory standards, and thus be independent of the observations. This has recently become a well-supported aim, following the discovery of the acceleration of the cosmic expansion by use of type-Ia supernovae, and has led to plans for launching calibration rockets for the visible and infrared spectral range. This is timely, too, because an adequate exploitation of data from present space missions, such as Gaia, and from many current astronomical projects like Euclid and WFIRST demands higher radiometric accuracy than is generally available today. A survey of the calibration of instruments observing from the X-ray to the infrared spectral domains that include instrument- or mission-specific estimates of radiometric accuracies rounds off this review.

  8. Towers for Antarctic Telescopes

    NASA Astrophysics Data System (ADS)

    Hammerschlag, R. H.; Bettonvil, F. C. M.; Jägers, A. P. L.; Nielsen, G.

    To take advantage of the exceptional seeing above the boundary layer on Antarctic sites, a high-resolution telescope must be mounted on a support tower. An open transparent tower of framework minimizes the upward temperature-disturbed airflow. A typical minimum height is 30m. The tower platform has to be extremely stable against wind-induced rotational motions, which have to be less than fractions of an arc second, unusually small from a mechanical engineering viewpoint. In a traditional structure, structural deflections result in angular deflections of the telescope platform, which introduce tip and tilt motions in the telescope. However, a structure that is designed to deflect with parallel motion relative to the horizontal plane will undergo solely translation deflections in the telescope platform and thus will not degrade the image. The use of a parallel motion structure has been effectively demonstrated in the design of the 15-m tower for the Dutch Open Telescope (DOT) on La Palma. Special framework geometries are developed, which make it possible to construct high towers in stories having platforms with extreme stability against wind-induced tilt. These geometric solutions lead to constructions, being no more massive than a normal steel framework carrying the same load. Consequently, these lightweight towers are well suited to difficult sites as on Antarctica. A geometry with 4 stories has been worked out.

  9. The Travelling Telescope

    NASA Astrophysics Data System (ADS)

    Murabona Oduori, Susan

    2015-08-01

    The telescope has been around for more than 400 years, and through good use of it scientists have made many astonishing discoveries and begun to understand our place in the universe. Most people, however, have never looked through one. Yet it is a great tool for cool science and observation especially in a continent and country with beautifully dark skies. The Travelling Telescope project aims to invite people outside under the stars to learn about those curious lights in the sky.The Travelling Telescope aims to promote science learning to a wide range of Kenyan schools in various locations exchanging knowledge about the sky through direct observations of celestial bodies using state of the art telescopes. In addition to direct observing we also teach science using various hands-on activities and astronomy software, ideal for explaining concepts which are hard to understand, and for a better grasp of the sights visible through the telescope. We are dedicated to promoting science using astronomy especially in schools, targeting children from as young as 3 years to the youth, teachers, their parents and members of the public. Our presentation focuses on the OAD funded project in rural coastal Kenya.

  10. Robotic and Survey Telescopes

    NASA Astrophysics Data System (ADS)

    Woźniak, Przemysław

    Robotic telescopes are revolutionizing the way astronomers collect their dataand conduct sky surveys. This chapter begins with a discussion of principles thatguide the process of designing, constructing, and operating telescopes andobservatories that offer a varying degree of automation, from instruments remotelycontrolled by observers to fully autonomous systems requiring no humansupervision during their normal operations. Emphasis is placed on designtrade-offs involved in building end-to-end systems intended for a wide range ofscience applications. The second part of the chapter contains descriptions ofseveral projects and instruments, both existing and currently under development.It is an attempt to provide a representative selection of actual systems thatillustrates state of the art in technology, as well as important ideas and milestonesin the development of the field. The list of presented instruments spans the fullrange in size starting from small all-sky monitors, through midrange robotic andsurvey telescopes, and finishing with large robotic instruments and surveys.Explosive growth of telescope networking is enabling entirely new modesof interaction between the survey and follow-up observing. Increasingimportance of standardized communication protocols and software is stressed.These developments are driven by the fusion of robotic telescope hardware,massive storage and databases, real-time knowledge extraction, and datacross-correlation on a global scale. The chapter concludes with examplesof major science results enabled by these new technologies and futureprospects.

  11. Antenna-coupled TES bolometers used in BICEP2, Keck Array, and SPIDER

    DOE PAGES

    Ade, P. A. R.; Aikin, R. W.; Amiri, M.; ...

    2015-10-20

    We have developed antenna-coupled transition-edge sensor bolometers for a wide range of cosmic microwave background (CMB) polarimetry experiments, including Bicep2, Keck Array, and the balloon borne Spider. These detectors have reached maturity and this paper reports on their design principles, overall performance, and key challenges associated with design and production. Our detector arrays repeatedly produce spectral bands with 20%–30% bandwidth at 95, 150, or 230 GHz. The integrated antenna arrays synthesize symmetric co-aligned beams with controlled side-lobe levels. Cross-polarized response on boresight is typicallymore » $$\\sim 0.5\\%$$, consistent with cross-talk in our multiplexed readout system. End-to-end optical efficiencies in our cameras are routinely 35% or higher, with per detector sensitivities of NET ~ 300 $$\\mu {{\\rm{K}}}_{\\mathrm{CMB}}\\sqrt{{\\rm{s}}}$$. Thanks to the scalability of this design, we have deployed 2560 detectors as 1280 matched pairs in Keck Array with a combined instantaneous sensitivity of $$\\sim 9\\;\\mu {{\\rm{K}}}_{\\mathrm{CMB}}\\sqrt{{\\rm{s}}}$$, as measured directly from CMB maps in the 2013 season. Furthermore, similar arrays have recently flown in the Spider instrument, and development of this technology is ongoing.« less

  12. Antenna-coupled TES Bolometers Used in BICEP2, Keck Array, and Spider

    NASA Astrophysics Data System (ADS)

    BICEP2 Collaboration; Keck Array Collaboration; SPIDER Collaboration; Ade, P. A. R.; Aikin, R. W.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bonetti, J. A.; Brevik, J. A.; Buder, I.; Bullock, E.; Chattopadhyay, G.; Davis, G.; Day, P. K.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hristov, V.; Hui, H.; Irwin, K. D.; Jones, W. C.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; LeDuc, H. G.; Leitch, E. M.; Llombart, N.; Lueker, M.; Mason, P.; Megerian, K.; Moncelsi, L.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Rahlin, A. S.; Reintsema, C. D.; Richter, S.; Runyan, M. C.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Tolan, J. E.; Trangsrud, A.; Tucker, R. S.; Turner, A. D.; Vieregg, A. G.; Weber, A.; Wiebe, D. V.; Wilson, P.; Wong, C. L.; Yoon, K. W.; Zmuidzinas, J.

    2015-10-01

    We have developed antenna-coupled transition-edge sensor bolometers for a wide range of cosmic microwave background (CMB) polarimetry experiments, including Bicep2, Keck Array, and the balloon borne Spider. These detectors have reached maturity and this paper reports on their design principles, overall performance, and key challenges associated with design and production. Our detector arrays repeatedly produce spectral bands with 20%-30% bandwidth at 95, 150, or 230 GHz. The integrated antenna arrays synthesize symmetric co-aligned beams with controlled side-lobe levels. Cross-polarized response on boresight is typically ˜ 0.5%, consistent with cross-talk in our multiplexed readout system. End-to-end optical efficiencies in our cameras are routinely 35% or higher, with per detector sensitivities of NET ˜ 300 μ {K}{CMB}√{s}. Thanks to the scalability of this design, we have deployed 2560 detectors as 1280 matched pairs in Keck Array with a combined instantaneous sensitivity of ˜ 9 μ {K}{CMB}√{s}, as measured directly from CMB maps in the 2013 season. Similar arrays have recently flown in the Spider instrument, and development of this technology is ongoing.

  13. The Nuclear Compton Telescope

    NASA Astrophysics Data System (ADS)

    Boggs, Steven E.; NCT Collaboration

    2011-09-01

    The Nuclear Compton Telescope (NCT) is a balloon-borne soft gamma-ray (0.2-10 MeV) telescope designed to perform wide-field imaging, high-resolution spectroscopy, and novel polarization analysis of astrophysical sources. NCT employs a novel Compton telescope design, utilizing 12 high spectral resolution germanium detectors, with the ability to localize photon interaction in three dimensions. NCT underwent its first science flight from Fort Sumner, NM in Spring 2009, and was partially destroyed during a second launch attempt from Alice Spring, Australia in Spring 2010. We will present an overview of the NCT program, including results from the Spring 2009 flight, as well as status and plans for the NCT program.

  14. Configurable Aperture Space Telescope

    NASA Technical Reports Server (NTRS)

    Ennico, Kimberly; Vassigh, Kenny; Bendek, Selman; Young, Zion W; Lynch, Dana H.

    2015-01-01

    In December 2014, we were awarded Center Innovation Fund to evaluate an optical and mechanical concept for a novel implementation of a segmented telescope based on modular, interconnected small sats (satlets). The concept is called CAST, a Configurable Aperture Space Telescope. With a current TRL is 2 we will aim to reach TLR 3 in Sept 2015 by demonstrating a 2x2 mirror system to validate our optical model and error budget, provide strawman mechanical architecture and structural damping analyses, and derive future satlet-based observatory performance requirements. CAST provides an alternative access to visible andor UV wavelength space telescope with 1-meter or larger aperture for NASA SMD Astrophysics and Planetary Science community after the retirement of HST.

  15. Configurable Aperture Space Telescope

    NASA Technical Reports Server (NTRS)

    Ennico, Kimberly; Bendek, Eduardo

    2015-01-01

    In December 2014, we were awarded Center Innovation Fund to evaluate an optical and mechanical concept for a novel implementation of a segmented telescope based on modular, interconnected small sats (satlets). The concept is called CAST, a Configurable Aperture Space Telescope. With a current TRL is 2 we will aim to reach TLR 3 in Sept 2015 by demonstrating a 2x2 mirror system to validate our optical model and error budget, provide straw man mechanical architecture and structural damping analyses, and derive future satlet-based observatory performance requirements. CAST provides an alternative access to visible and/or UV wavelength space telescope with 1-meter or larger aperture for NASA SMD Astrophysics and Planetary Science community after the retirement of HST

  16. LSST telescope modeling overview

    NASA Astrophysics Data System (ADS)

    Sebag, J.; Andrew, J.; Angeli, G.; Araujo, C.; Barr, J.; Callahan, S.; Cho, M.; Claver, C.; Daruich, F.; Gressler, W.; Hileman, E.; Liang, M.; Muller, G.; Neill, D.; Schoening, W.; Warner, M.; Wiecha, O.; Xin, B.; Orden Martinez, Alfredo; Perezagua Aguado, Manuel; García Marchena, Luis; Ruiz de Argandoña, Ismael

    2016-08-01

    During this early stage of construction of the Large Synoptic Survey Telescope (LSST), modeling has become a crucial system engineering process to ensure that the final detailed design of all the sub-systems that compose the telescope meet requirements and interfaces. Modeling includes multiple tools and types of analyses that are performed to address specific technical issues. Three-dimensional (3D) Computeraided Design (CAD) modeling has become central for controlling interfaces between subsystems and identifying potential interferences. The LSST Telescope dynamic requirements are challenging because of the nature of the LSST survey which requires a high cadence of rapid slews and short settling times. The combination of finite element methods (FEM), coupled with control system dynamic analysis, provides a method to validate these specifications. An overview of these modeling activities is reported in this paper including specific cases that illustrate its impact.

  17. Ultrathin zoom telescopic objective.

    PubMed

    Li, Lei; Wang, Di; Liu, Chao; Wang, Qiong-Hua

    2016-08-08

    We report an ultrathin zoom telescopic objective that can achieve continuous zoom change and has reduced compact volume. The objective consists of an annular folded lens and three electrowetting liquid lenses. The annular folded lens undertakes the main part of the focal power of the lens system. Due to a multiple-fold design, the optical path is folded in a lens with the thickness of ~1.98mm. The electrowetting liquid lenses constitute a zoom part. Based on the proposed objective, an ultrathin zoom telescopic camera is demonstrated. We analyze the properties of the proposed objective. The aperture of the proposed objective is ~15mm. The total length of the system is ~18mm with a tunable focal length ~48mm to ~65mm. Compared with the conventional zoom telescopic objective, the total length has been largely reduced.

  18. The Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Millis, R. L.; Dunham, E. W.; Sebring, T. A.; Smith, B. W.; de Kock, M.; Wiecha, O.

    2004-11-01

    The Discovery Channel Telescope (DCT) is a 4.2-m telescope to be built at a new site near Happy Jack, Arizona. The DCT features a large prime focus mosaic CCD camera with a 2-degree-diameter field of view especially designed for surveys of KBOs, Centaurs, NEAs and other moving or time-variable targets. The telescope can be switched quickly to a Ritchey-Chretien configuration for optical/IR spectroscopy or near-IR imaging. This flexibility allows timely follow-up physical studies of high priority objects discovered in survey mode. The ULE (ultra-low-expansion) meniscus primary and secondary mirror blanks for the telescope are currently in fabrication by Corning Glass. Goodrich Aerospace, Vertex RSI, M3 Engineering and Technology Corp., and e2v Technologies have recently completed in-depth conceptual design studies of the optics, mount, enclosure, and mosaic focal plane, respectively. The results of these studies were subjected to a formal design review in July, 2004. Site testing at the 7760-ft altitude Happy Jack site began in 2001. Differential image motion observations from 117 nights since January 1, 2003 gave median seeing of 0.84 arcsec FWHM, and the average of the first quartile was 0.62 arcsec. The National Environmental Policy Act (NEPA) process for securing long-term access to this site on the Coconino National Forest is nearing completion and ground breaking is expected in the spring of 2005. The Discovery Channel Telescope is a project of the Lowell Observatory with major financial support from Discovery Communications, Inc. (DCI). DCI plans ongoing television programming featuring the construction of the telescope and the research ultimately undertaken with the DCT. An additional partner can be accommodated in the project. Interested parties should contact the lead author.

  19. The ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Distefano, Carla

    The ANTARES collaboration has completed in 2008 the construction of an underwater high-energy neutrino telescope in the Mediterranean Sea, located 40 km off the French coast at a depth of 2500 m. The detector consists of 885 optical modules, which are distributed in 12 detector lines, various calibration systems and devices for environmental measurements. With an instrumented volume of about 0.05 km3, ANTARES is the largest Cherenkov neutrino detector currently operating in the Northern hemisphere. A general overview on the ANTARES telescope is given. The preliminary results from the various physics analyses on the collected data will be presented.

  20. First Results from the Telescope Array RAdar (TARA) Detector

    NASA Astrophysics Data System (ADS)

    Myers, Isaac

    2014-03-01

    The TARA cosmic ray detector has been in operation for about a year and a half. This bi-static radar detector was designed with the goal of detecting cosmic rays in coincidence with Telescope Array (TA). A new high power (25 kW, 5 MW effective radiated power) transmitter and antenna array and 250 MHz fPGA-based DAQ have been operational since August 2013. The eight-Yagi antenna array broadcasts a 54.1 MHz tone across the TA surface detector array toward our receiver station 50 km away at the Long Ridge fluorescence detector. Receiving antennas feed an intelligent DAQ that self-adjusts to the fluctuating radio background and which employs a bank of matched filters that search in real-time for chirp radar echoes. Millions of triggers have been collected in this mode. A second mode is a forced trigger scheme that uses the trigger status of the fluorescence telescope. Of those triggers collected in FD-triggered mode, about 800 correspond with well-reconstructed TA events. I will describe recent advancements in calibrating key components in the transmitter and receiver RF chains and the analysis of FD-triggered data. Work supported by W.M. Keck Foundation and NSF.

  1. A Detailed Gravitational Lens Model Based on Submillimeter Array and Keck Adaptive Optics Imaging of a Herschel-ATLAS Submillimeter Galaxy at z = 4.243

    NASA Astrophysics Data System (ADS)

    Bussmann, R. S.; Gurwell, M. A.; Fu, Hai; Smith, D. J. B.; Dye, S.; Auld, R.; Baes, M.; Baker, A. J.; Bonfield, D.; Cava, A.; Clements, D. L.; Cooray, A.; Coppin, K.; Dannerbauer, H.; Dariush, A.; De Zotti, G.; Dunne, L.; Eales, S.; Fritz, J.; Hopwood, R.; Ibar, E.; Ivison, R. J.; Jarvis, M. J.; Kim, S.; Leeuw, L. L.; Maddox, S.; Michałowski, M. J.; Negrello, M.; Pascale, E.; Pohlen, M.; Riechers, D. A.; Rigby, E.; Scott, Douglas; Temi, P.; Van der Werf, P. P.; Wardlow, J.; Wilner, D.; Verma, A.

    2012-09-01

    We present high-spatial resolution imaging obtained with the Submillimeter Array (SMA) at 880 μm and the Keck adaptive optics (AO) system at the K S-band of a gravitationally lensed submillimeter galaxy (SMG) at z = 4.243 discovered in the Herschel Astrophysical Terahertz Large Area Survey. The SMA data (angular resolution ≈0farcs6) resolve the dust emission into multiple lensed images, while the Keck AO K S-band data (angular resolution ≈0farcs1) resolve the lens into a pair of galaxies separated by 0farcs3. We present an optical spectrum of the foreground lens obtained with the Gemini-South telescope that provides a lens redshift of z lens = 0.595 ± 0.005. We develop and apply a new lens modeling technique in the visibility plane that shows that the SMG is magnified by a factor of μ = 4.1 ± 0.2 and has an intrinsic infrared (IR) luminosity of L IR = (2.1 ± 0.2) × 1013 L ⊙. We measure a half-light radius of the background source of r s = 4.4 ± 0.5 kpc which implies an IR luminosity surface density of ΣIR = (3.4 ± 0.9) × 1011 L ⊙ kpc-2, a value that is typical of z > 2 SMGs but significantly lower than IR luminous galaxies at z ~ 0. The two lens galaxies are compact (r lens ≈ 0.9 kpc) early-types with Einstein radii of θE1 = 0.57 ± 0.01 and θE2 = 0.40 ± 0.01 that imply masses of M lens1 = (7.4 ± 0.5) × 1010 M ⊙ and M lens2 = (3.7 ± 0.3) × 1010 M ⊙. The two lensing galaxies are likely about to undergo a dissipationless merger, and the mass and size of the resultant system should be similar to other early-type galaxies at z ~ 0.6. This work highlights the importance of high spatial resolution imaging in developing models of strongly lensed galaxies discovered by Herschel. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. Tracing The Origin Of Methane And Water On Mars: Mapping Regions Of Active Release At Ultra-high Spatial Resolution Using Keck And VLT Under AO Control.

    NASA Astrophysics Data System (ADS)

    Mumma, Michael J.; Villanueva, G. L.; Campbell, R.; Lyke, J.; Conrad, A.; Encrenaz, T.; Hartogh, P.; Kauefl, U.; Novak, R. E.; Tokunaga, A.

    2009-09-01

    Strong release of methane from active regions on Mars has been reported in northern summer (1) and southern spring (2). The spatial resolution of these measurements was about 500 km, sufficient to reveal discrete active regions. Regions of methane release appear mainly over ancient terrain (Noachian/Hesperian) known to have a rich hydration history, and often marked by fossae or other scarps. However, higher resolution is needed to test whether methane release is confined to a small number of narrowly defined vents or is widely distributed over the 500 km footprint. If narrowly confined, the plume should have correspondingly higher local density, enhancing spectral searches for water, methane, their isotopologues, and other trace gases that could reveal aspects of methane generation and depth of release. Ground-based telescopes equipped with both adaptive optics (AO) and high dispersion infrared spectrometers have delivered much higher spatial resolution on planetary bodies, but until now have not been applied to Mars. We acquired images and spectra of Mars under AO control at infrared wavelengths, using Keck-2 and ESO-VLT. In June 2009, we acquired test images with NIRC2/Keck-2 using AO in the natural guide star mode and achieved 0.12” FWHM resolution at 3.0 µm wavelength (Mars diameter was 4.7"). Diffraction-limited performance (0.06” at 3 µm) is expected during follow-up observations in September 2009. We observed Mars with UT1 under AO control (MACAO) in August and September 2009, and acquired spectra with CRIRES. We expect to achieve spatial resolution approaching 40 km in November-December 2009, representing a reduction in area by nearly a factor of 100 compared with earlier non-AO searches. Preliminary results will be presented. This work was funded by NASA grants 08-PAST08-0034 (Planetary Astronomy) and 08-PATM080-0031 (Planetary Atmospheres). 1. Mumma, Villanueva, Novak et al., Science 323, 1041 (2009) 2. Villanueva, Mumma, Novak, (in prep) 2009.

  3. The Automated Planet Finder telescope's automation and first three years of planet detections

    NASA Astrophysics Data System (ADS)

    Burt, Jennifer

    2016-08-01

    The Automated Planet Finder (APF) is a 2.4m, f/15 telescope located at the UCO's Lick Observatory, atop Mt. Hamilton. The telescope has been specifically optimized to detect and characterize extrasolar planets via high precision, radial velocity (RV) observations using the high-resolution Levy echelle spectrograph. The telescope has demonstrated world-class internal precision levels of 1 m/s when observing bright, RV standard stars. Observing time on the telescope is divided such that ˜80% is spent on exoplanet related research and the remaining ˜20% is made available to the University of California consortium for other science goals. The telescope achieved first light in 2013, and this work describes the APF's early science achievements and its transition from a traditional observing approach to a fully autonomous facility. First we provide a characteristic look at the APF telescope and the Levy spectrograph, focusing on the stability of the instrument and its performance on RV standard stars. Second, we describe the design and implementation of the dynamic scheduling software which has been running our team's nightly observations on the APF for the past year. Third, we discuss the detection of a Neptune-mass planet orbiting the nearby, low-mass star GL687 by the APF in collaboration with the HIRES instrument on Keck I. Fourth, we summarize the APF's detection of two multi-planet systems: the four planet system orbiting HD 141399 and the 6 planet system orbiting HD 219134. Fifth, we expand our science focus to assess the impact that the APF - with the addition of a new, time-varying prioritization scheme to the telescope's dynamic scheduling software - can have on filling out the exoplanet Mass-Radius diagram when pursuing RV follow-up of transiting planets detected by NASA's TESS satellite. Finally, we outline some likely next science goals for the telescope.

  4. AO Images of Asteroids, Inverting their Lightcurves, and SSA

    DTIC Science & Technology

    2008-09-01

    twin 10 m Keck telescopes on Mauna Kea . In this paper we compare the models of Kassalainen to images obtained at Keck, and show both the validity of the...and rotational poles of seven asteroids from Lick Observatory adaptive optics images, and of Ceres. Icarus in press, doi:10.1016/j.icarus.2008.05.009 4

  5. Apollo Telescope Mount Illustration

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Apollo Telescope Mount (ATM) served as the first marned astronomical observatory in space. It was designed for solar research from Earth orbit aboard the Skylab. This image is a cutaway illustration of the ATM canister with callouts and characteristics. The ATM was designed and developed by the Marshall Space Flight Center.

  6. Apollo Telescope Mount Illustration

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The Apollo Telescope Mount (ATM) served as the first marned astronomical observatory in space. It was designed for solar research from Earth orbit aboard the Skylab. This image is a cutaway illustration of the ATM canister. The ATM was designed and developed by the Marshall Space Flight Center.

  7. Apollo Telescope Mount Illustration

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The Apollo Telescope Mount (ATM) served as the first marned astronomical observatory in space. It was designed for solar research from Earth orbit aboard the Skylab. This image is a cutaway illustration of the ATM canister with callouts. The ATM was designed and developed by the Marshall Space Flight Center.

  8. A Simple "Tubeless" Telescope

    ERIC Educational Resources Information Center

    Straulino, S.; Bonechi, L.

    2010-01-01

    Two lenses make it possible to create a simple telescope with quite large magnification. The set-up is very simple and can be reproduced in schools, provided the laboratory has a range of lenses with different focal lengths. In this article, the authors adopt the Keplerian configuration, which is composed of two converging lenses. This instrument,…

  9. The Falcon Telescope Network

    NASA Astrophysics Data System (ADS)

    Chun, F.; Tippets, R.; Dearborn, M.; Gresham, K.; Freckleton, R.; Douglas, M.

    2014-09-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. Since the FTN has a general use purpose, objects of interest include satellites, astronomical research, and STEM support images. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA in the Cadet Space Operations Center. FTN users will be able to submit observational requests via a web interface. The requests will then be prioritized based on the type of user, the object of interest, and a user-defined priority. A network wide schedule will be developed every 24 hours and each FTN site will autonomously execute its portion of the schedule. After an observational request is completed, the FTN user will receive notification of collection and a link to the data. The Falcon Telescope Network is an ambitious endeavor, but demonstrates the cooperation that can be achieved by multiple educational institutions.

  10. Exploring Galileo's Telescope

    ERIC Educational Resources Information Center

    Straulino, Samuele; Terzuoli, Alessandra

    2010-01-01

    In the first months of 2009, the International Year of Astronomy, the authors developed an educational project for middle-level students connected with the first astronomical discoveries that Galileo Galilei (1564-1642) made 400 years ago. The project included the construction of a basic telescope and the observation of the Moon. The project, if…

  11. The Liverpool Telescope

    NASA Astrophysics Data System (ADS)

    Smith, Robert J.; Bates, S. D.; Clay, Neil R.; Fraser, Stephen N.; Marchant, J. M.; Mottram, C. J.; Steele, I. A.; Tomlinson, M. D.

    2011-03-01

    The Liverpool Telescope (LT) is a fully robotic 2m optical telescope at a world-class observatory site. It runs autonomously without direct human control either on site or remotely. It is not operated primarily for a single science project, but rather is a common-user facility, time allocated by an open, peer-review process and conducting a variety of optical and IR imaging, spectroscopic and polarimetric programs. This paper describes some of aspects of the site infrastructure and instrument suite designed specifically to support robust and reliable unsupervised operations. Aside from the telescope hardware, the other aspect of robotic operations is the mechanisms whereby users interact with the telescope and its automated scheduler. We describe how these have been implemented for the LT. Observing routinely since 2004, the LT has demonstrated it is possible to operate a large, common-user robotic observatory. Making the most of the flexibility afforded by fully robotic operations, development continues in collaboration with both observers and other observatories to develop observing modes to enable new science across the broad discipline of time-domain astrophysics.

  12. Wearable telescopic contact lens.

    PubMed

    Arianpour, Ashkan; Schuster, Glenn M; Tremblay, Eric J; Stamenov, Igor; Groisman, Alex; Legerton, Jerry; Meyers, William; Amigo, Goretty Alonso; Ford, Joseph E

    2015-08-20

    We describe the design, fabrication, and testing of a 1.6 mm thick scleral contact lens providing both 1× and 2.8× magnified vision paths, intended for use as a switchable eye-borne telescopic low-vision aid. The F/9.7 telescopic vision path uses an 8.2 mm diameter annular entrance pupil and 4 internal reflections in a polymethyl methacrylate precision optic. This gas-impermeable insert is contained inside a smooth outer casing of rigid gas-permeable polymer, which also provides achromatic correction for refraction at the curved lens face. The unmagnified F/4.1 vision path is through the central aperture of the lens, with additional transmission between the annular telescope rings to enable peripheral vision. We discuss potential solutions for providing oxygenation for an extended wear version of the lens. The prototype lenses were characterized using a scale-model human eye, and telescope functionality was confirmed in a small-scale clinical (nondispensed) demonstration.

  13. Hubble Space Telescope Assembly

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Engineers and technicians conduct a fit check of the Hubble Space Telescope (HST) Solar Array flight article in a clean room of the Lockheed Missile and Space Company. The Solar Array is 40- feet (12.1-meters) long and 8.2-feet (2.5-meters) wide, and provides power to the spacecraft. The HST is the first of NASA's great observatories and the most complex and sensitive optical telescope ever made. The purpose of the HST is to study the cosmos from a low-Earth orbit by placing the telescope in space, enabling astronomers to collect data that is free of the Earth's atmosphere. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had overall responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company, Sunnyvale, California, produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  14. Membrane photon sieve telescopes.

    PubMed

    Andersen, Geoff

    2010-11-20

    We present results of research into the design and construction of membrane photon sieves as primaries for next-generation lightweight space telescopes. We have created prototypes in electroformed nickel as well as diazo and CP-1 polymer films. In two such cases, diffraction-limited imaging performance was demonstrated over a narrow bandwidth.

  15. A Novel Dust Telescope

    NASA Astrophysics Data System (ADS)

    Grün, E.; Srama, R.; Krüger, H.; Kempf, S.; Harris, D.; Conlon, T.; Auer, S.

    2001-11-01

    Dust particles in space, like photons, are born at remote sites in space and time. From knowledge of the dust particles' birthplace and the particles' bulk properties, we can learn about the remote environment out of which the particles were formed. This approach is carried out by means of a dust telescope on a dust observatory in space. A dust telescope is a combination of a dust trajectory sensor together with a chemical composition analyzer for dust particles. A novel dust telescope is described. It consists of a highly sensitive dust trajectory sensor, and a large area chemical dust analyzer. It can provide valuable information about the particles' birthplace which may not be accessible by other techniques. Dust particles' trajectories are determined by the measurement of the electric signals that are induced when a charged grain flies through an appropriately configured electrode systems. After the successful identification of a few charged micron-sized dust grains in space by the Cassini Cosmic Dust Analyzer, this dust telescope has a ten fold increased sensitivity of charge detection (10-16 Coulombs) and will be able to obtain trajectories for sub-micron sized dust grains. State-of-the art dust chemical analyzers have sufficient mass resolution to resolve ions with atomic mass numbers above 100. However, since their impact areas are small they can analyze statistically meaningful numbers of grains only in the dust-rich environments of comets or ringed planets. Therefore, this dust telescope includes a large area (0.1 m2) chemical dust analyzer of mass resolution > 100 that will allow us to obtain statistically significant measurements of interplanetary and interstellar dust grains in space.

  16. Giant Magellan Telescope: overview

    NASA Astrophysics Data System (ADS)

    Johns, Matt; McCarthy, Patrick; Raybould, Keith; Bouchez, Antonin; Farahani, Arash; Filgueira, Jose; Jacoby, George; Shectman, Steve; Sheehan, Michael

    2012-09-01

    The Giant Magellan Telescope (GMT) is a 25-meter optical/infrared extremely large telescope that is being built by an international consortium of universities and research institutions. It will be located at the Las Campanas Observatory, Chile. The GMT primary mirror consists of seven 8.4-m borosilicate honeycomb mirror segments made at the Steward Observatory Mirror Lab (SOML). Six identical off-axis segments and one on-axis segment are arranged on a single nearly-paraboloidal parent surface having an overall focal ratio of f/0.7. The fabrication, testing and verification procedures required to produce the closely-matched off-axis mirror segments were developed during the production of the first mirror. Production of the second and third off-axis segments is underway. GMT incorporates a seven-segment Gregorian adaptive secondary to implement three modes of adaptive-optics operation: natural-guide star AO, laser-tomography AO, and ground-layer AO. A wide-field corrector/ADC is available for use in seeing-limited mode over a 20-arcmin diameter field of view. Up to seven instruments can be mounted simultaneously on the telescope in a large Gregorian Instrument Rotator. Conceptual design studies were completed for six AO and seeing-limited instruments, plus a multi-object fiber feed, and a roadmap for phased deployment of the GMT instrument suite is being developed. The partner institutions have made firm commitments for approximately 45% of the funds required to build the telescope. Project Office efforts are currently focused on advancing the telescope and enclosure design in preparation for subsystem- and system-level preliminary design reviews which are scheduled to be completed in the first half of 2013.

  17. Keck spectroscopy of z = 1-3 ULIRGs from the Spitzer SWIRE survey

    NASA Astrophysics Data System (ADS)

    Berta, S.; Lonsdale, C. J.; Siana, B.; Farrah, D.; Smith, H. E.; Polletta, M. C.; Franceschini, A.; Fritz, J.; Perez-Fournon, I.; Rowan-Robinson, M.; Shupe, D.; Surace, J.

    2007-05-01

    Context: High-redshift ultra luminous infrared galaxies contribute the bulk of the cosmic IR background and are the best candidates for very massive galaxies in formation at z>1.5. Aims: It is necessary to identify the energy source for their huge luminosities, starburst or AGN activity, in order to correctly interpret the role of ULIRGs in galaxy evolution, and compute reliable estimates of their star formation rates, stellar masses, and accretion luminosities. Methods: We present Keck/LRIS optical spectroscopy of 35 z≥1.4 luminous IR galaxies in the Spitzer Wide-area Infra-Red Extragalactic survey (SWIRE) northern fields (Lockman Hole, ELAIS-N1, ELAIS-N2). The primary targets belong to the "IR-peak" class of galaxies, having the 1.6 μm (restframe) stellar feature detected in the IRAC Spitzer channels. The spectral energy distributions of the main targets are thoroughly analyzed, by means of spectro-photometric synthesis and multi-component fits (stars + starburst dust + AGN torus). Results: The IR-peak selection technique is confirmed to successfully select objects above z=1.4, though some of the observed sources lie at lower redshift than expected. Among the 16 galaxies with spectroscopic redshift, 62% host an AGN component, two thirds being type-1 and one third type-2 objects. The selection, limited to r'<24.5, is likely biased to optically-bright AGNs. All IR-peakers without emission lines have a non negligible continuum detection, and are likely to be very powerful starbursts, heavily extinguished by dust (A_V≥5 mag). The SEDs of non-AGN IR-peakers resemble those of starbursts ({SFR}=20-500 M_⊙/yr) hosted in massive (M>1011 M_⊙) galaxies. The presence of an AGN component provides a plausible explanation for the spectroscopic/photometric redshift discrepancies, as the torus produces an apparent shift of the peak to longer wavelengths. These sources are analyzed in IRAC and optical-IR color spaces. In addition to the IR-peak galaxies, we present

  18. Design solutions for dome and main structure (mount) of giant telescopes

    NASA Astrophysics Data System (ADS)

    Murga, Gaizka; Bilbao, Armando; de Bilbao, Lander; Lorentz, Thomas E.

    2016-07-01

    During the last recent years, designs for several giant telescopes ranging from 20 to 40m in diameter are being developed: European Extremely Large Telescope Telescope (TMT). (E-ELT), Giant Magellan Telescope (GMT) and Thirty Meter It is evident that simple direct up-scaling of solutions that were more or less successful in the 8 to 10m class telescopes can not lead to viable designs for the future giant telescopes. New solutions are required to provide adequate load sharing, to cope with the large-scale derived deflections and to provide the required compliance, or to respond to structure-mechanism control interaction issues, among others. From IDOM experience in the development of the Dome and Main Structure of the European Extremely Large Telescope and our participation in some other giant telescopes, this paper reviews several design approaches for the main mechanisms and key structural parts of enclosures and mounts/main structures for giant telescopes, analyzing pros and cons of the different alternatives and outlining the preferred design schemes. The assessment is carried out mainly from a technical and performance-based angle but it also considers specific logistical issues for the assembly of these large telescopes in remote and space-limited areas, together with cost and schedule related issues.

  19. Wavefront Analysis of Adaptive Telescope

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Hillman, Lloyd

    1997-01-01

    The motivation for this work came from a NASA Headquarters interest in investigating design concepts for a large space telescope employing active optics technology. The development of telescope optical requirements and potential optical design configurations is reported.

  20. Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

    NASA Astrophysics Data System (ADS)

    Baldauf, Brian; Conti, Alberto

    2016-01-01

    The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The High Definition Space Telescope (HDST) envisioned for this mission would have an aperture >10 m, which is a larger payload than what can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. Space-based telescopes with large apertures will require major changes to system architectures.The Optical Telescope Assembly (OTA) for HDST is a primary mission cost driver. Enabling and affordable solutions for this next generation of large aperture space-based telescope are needed.This paper reports on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST), which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will also facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, and a testbed for new instruments. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Other key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal

  1. Identifying Young Kepler Planet Host Stars from Keck-HIRES Spectra of Lithium

    NASA Astrophysics Data System (ADS)

    Berger, Travis Allen; Howard, Andrew; Boesgaard, Ann M.

    2017-01-01

    The lithium doublet at 6708 A provides an age diagnostic for FGK stars. We measured the abundance of lithium in 1149 stars with detected transiting planets from the Kepler Mission using high resolution spectroscopy. Our catalog of lithium measurements from this sample have a range of abundance from A(Li) = 3.13 +/- 0.05 to a lower limit of -0.79. For a magnitude-limited sample that comprises 930 of the 1149 stars, our Keck-HIRES spectra have a median S/N = 45 per pixel at spectral resolution R = 55,000. We identify 79 young stars that have A(Li) values greater than the Hyades at their respective effective temperatures; these stars are younger than ~650 Myr old, the approximate age of the Hyades. We then compare the distribution of A(Li) with planet size, disposition, multiplicity, orbital period, and insolation flux.

  2. The Keck OSIRIS Nearby AGN (KONA) Survey: AGN Fueling and Feedback

    NASA Astrophysics Data System (ADS)

    Hicks, Erin K. S.; Müller-Sánchez, Francisco; Malkan, Matthew A.; Yu, Po-Chieh

    In an effort to better constrain the relevant physical processes dictating the co-evolution of supermassive black holes and the galaxies in which they reside we turn to local Seyfert AGN. It is only with these local AGN that we can reach the spatial resolution needed to adequately characterize the inflow and outflow mechanisms thought to be the driving forces in establishing the relationship between black holes and their host galaxies at higher redshift. We present the first results from the KONA (Keck OSIRIS Nearby AGN) survey, which takes advantage of the integral field unit OSIRIS plus laser and natural guide star adaptive optics to probe down to scales of 5-30 parsecs in a sample of 40 local Seyfert galaxies. With these K-band data we measure the two-dimensional distribution and kinematics of the nuclear stars, molecular gas, and ionized gas within the central few hundred parsecs.

  3. Adaptive optics observations of NGC 6240 at the Keck and Lick Observatories

    NASA Astrophysics Data System (ADS)

    Max, C. E.; Whysong, D.; Macintosh, B. A.; Antonucci, R.; Roe, H.

    2000-12-01

    NGC 6240 is a luminous IRAS galaxy, and contains a nuclear starburst that is about 10 million years old. NGC 6240 consists of two merging disk galaxies. It is a LINER, and may host one or two active galactic nuclei. Previous studies have detected high-velocity ionized gas flowing outward in a "superwind," as well as strong molecular hydrogen and [FeII] emission. Here we report on near-IR adaptive optics imaging and spectroscopy of NGC 6240 at the Keck and Lick Observatories. The twin nuclei are clearly resolved in both images and spectra. We report on the spatial distribution and velocity structure of the molecular hydrogen emission, and its implications for potential excitation mechanisms and physical conditions in the emitting gas. This research was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory, University of California, under Contract W-7405-ENG-48.

  4. The Chemical Evolution of Milky Way Satellite Galaxies from Keck Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kirby, Evan N.

    2015-03-01

    The primary data product of a recent Keck/DEIMOS spectroscopic campaign of eight Milky Way dwarf spheroidal (dSph) satellite galaxies is a catalog of nearly 3000 red giants with spectral synthesis-based abundance measurements of Fe and the α elements Mg, Si, Ca, and Ti. The dSph metallicity distributions show that the histories of the less luminous dSphs were marked by massive amounts of metal loss. The [α/Fe] distributions reveal that the early star formation histories (at a lookback time of >12 Gyr) of most dSphs were very similar and that Type Ia supernova ejecta contributed to the abundances of all but the most metal-poor ([Fe/H] < -2.5) stars. This large data set allows inferences of past outflows from the dSphs in order to determine their contribution to the metal content of the intergalactic medium.

  5. Uzaybimer Radio Telescope Control System

    NASA Astrophysics Data System (ADS)

    Balbay, R.; Öz, G. K.; Arslan, Ö.; Özeren, F. F.; Küçük, İ.

    2016-12-01

    A 13 meters former NATO radar is being converted into a radio telescope. The radio telescope is controlled by a system which has been developed at UZAYBİMER. The Telescope Control System(TCS) has been designed using modern industrial systems. TCS has been developed in LabView platform in which works Windows embedded OS. The position feedback used on radio telescopes is an industrial EtherCAT standard. ASCOM library is used for astronomical calculations.

  6. The Primeval Structure Telescope

    NASA Astrophysics Data System (ADS)

    Peterson, J. B.; Pen, U. L.; Wu, X. P.

    2004-12-01

    The Primeval Structure Telescope (PaST) will be used to study early ionization of the universe. The telescope will image and spectrally resolve hyperfine emission of neutral hydrogen at redshifts from about 6 to 20. Recently released data, obtained with the WMAP satellite, indicate that the universe was ionized very early, at around redshift 15. Right now, there is very little information on this ionization, since the WMAP data do not tell us the ionization history or the energy source. If the energy source was emission from collapsed objects, perhaps ultraviolet radiation from the first stars, the ionization did not occur homogenously. Earlier star formation in high-density regions causes these to be ionized first. Just when the ionization was half complete, the large-scale structure of the universe became visible in the ionization pattern. We will use redshifted 21 cm brightness to image the largest of the ionized bubbles in three dimensions, allowing us to determine the redshift of the early ionization. In addition, we will be able to study the evolution and merging of the ionized bubbles. PAST will be a sparse array telescope consisting of 10,000 log periodic antennas, providing over 50,000 square meters of effective collecting area. These antennas will be grouped into 80 phased arrays of 127 antennas. Current plans have these phased arrays fixed, pointed at the North Celestial Pole. Later, we can add electronic beam steering. Signals from the 80 phased arrays will be processed using a correlator built from a network of about 100 PC computers. The telescope will occupy ten square kilometers in the Ulastai Valley, Xin Jiang, China. The telescope will be built almost entirely of inexpensive commercially available off-the-shelf components. A series of tests of prototypes, made on-site, have allowed us to study the performance of the telescope and its components. We will present these results and show sky images obtained with the prototypes. We anticipate that one

  7. Comparisons of Monthly Mean 10 M Wind Speeds from Satellites and NWP Products Over the Global Ocean

    DTIC Science & Technology

    2009-10-09

    Resolution QSCAT SSM/I NOGAPS ERA-40 NCEP Sea Winds instrument on the Quick Scatterometer Special Sensor Microwave/Imager Navy Operational...measurements with 25-point smoothing as described earlier. [25] Within the latitudes spanning the Arctic and Antarctic , no ice mask is applied in order to...ET AL.: 10 M WINDS OVER THE GLOBAL OCEAN D16109 egies that blend two or more of these products to produce improved forcing fields. [53

  8. 17 CFR 249.510 - Form 10-M, consent to service of process by a nonresident general partner of a broker-dealer firm.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Form 10-M, consent to service... ACT OF 1934 Forms for Statements Made in Connection With Exempt Tender Offers § 249.510 Form 10-M... Note: For Federal Register citations affecting Form 10-M, see the List of CFR Sections Affected,...

  9. Structures and Stabilities of the Metal Doped Gold Nano-Clusters: M@Au10 (M = W, Mo, Ru, Co).

    PubMed

    Hossain, Delwar; Pittman, Charles U; Gwaltney, Steven R

    2014-01-01

    The structures and stabilities of a series of endohedral gold clusters containing ten gold atoms M@Au10 (M = W, Mo, Ru, Co) have been determined using density functional theory. The gradient-corrected functional BP86, the Tao-Perdew-Staroverov-Scuseria TPSS meta-GGA functional, and the hybrid density functionals B3LYP and PBE1PBE were employed to calculate the structures, binding energies, adiabatic ionization potentials, and adiabatic electron affinities for these clusters. The LanL2DZ effective core potentials and the corresponding valence basis sets were employed. The M@Au10 (M = W, Mo, Ru, Co) clusters have higher binding energies than an empty Au10 cluster. In addition, the large HOMO-LUMO gaps suggest that the M@Au10 (M = W, Mo, Ru, Co) clusters are all likely to be stable chemically. The ionization potentials and electron affinities for these clusters are very high, and the W@Au10 and Mo@Au10 clusters have electron affinities similar to the super-halogen Al13.

  10. Structures and Stabilities of the Metal Doped Gold Nano-Clusters: M@Au10 (M = W, Mo, Ru, Co)

    PubMed Central

    Hossain, Delwar; Pittman, Charles U.; Gwaltney, Steven R.

    2014-01-01

    The structures and stabilities of a series of endohedral gold clusters containing ten gold atoms M@Au10 (M = W, Mo, Ru, Co) have been determined using density functional theory. The gradient-corrected functional BP86, the Tao-Perdew-Staroverov-Scuseria TPSS meta-GGA functional, and the hybrid density functionals B3LYP and PBE1PBE were employed to calculate the structures, binding energies, adiabatic ionization potentials, and adiabatic electron affinities for these clusters. The LanL2DZ effective core potentials and the corresponding valence basis sets were employed. The M@Au10 (M = W, Mo, Ru, Co) clusters have higher binding energies than an empty Au10 cluster. In addition, the large HOMO–LUMO gaps suggest that the M@Au10 (M = W, Mo, Ru, Co) clusters are all likely to be stable chemically. The ionization potentials and electron affinities for these clusters are very high, and the W@Au10 and Mo@Au10 clusters have electron affinities similar to the super-halogen Al13. PMID:24611036

  11. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1991-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  12. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1992-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  13. Science operations with Space Telescope

    NASA Technical Reports Server (NTRS)

    Giacconi, R.

    1982-01-01

    The operation, instrumentation, and expected contributions of the Space Telescope are discussed. Space Telescope capabilities are described. The organization and nature of the Space Telescope Science Institute are outlined, including the allocation of observing time and the data rights and data access policies of the institute.

  14. Lowell Observatory's Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Hall, Jeffrey C.

    2017-01-01

    Lowell Observatory broke ground on its 4.3-meter Discovery Channel Telescope (DCT) in July 2005 and celebrated first light for the telescope in July 2012. In this overview to this special session, I will discuss the origin and development of the project, the telescope's general specifications and performance, its current operating status, and the initial instrument suite.

  15. The Bionic Telescope

    NASA Astrophysics Data System (ADS)

    Woolf, Neville

    2009-05-01

    Four hundred years after children in a spectacle makers workshop accidentally discovered the telescope, the development of this device has been a continuous replacement of the ``natural'' by the deliberate. The human eye is gone. The lens is gone. The tube is gone. The dome is on the verge of going. The size of the optics are ceasing to be set by transportation limits. Adaptive optics are preferred to stable optics. We deliberately break the Lagrange invariant. We focus on lasers instead of stars, and natural observing environments are being replaced by adaptive environments. The goals for the new ground based telescope encompass the oldest and newest ideas, to find signs of life elsewhere, and to find how all the universe developed.

  16. Origins Space Telescope

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha R.; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. I will summarize the OST STDT, mission design and instruments, key science drivers, and the study plan over the next two years.

  17. Telescopic limiting magnitudes

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.

    1990-01-01

    The prediction of the magnitude of the faintest star visible through a telescope by a visual observer is a difficult problem in physiology. Many prediction formulas have been advanced over the years, but most do not even consider the magnification used. Here, the prediction algorithm problem is attacked with two complimentary approaches: (1) First, a theoretical algorithm was developed based on physiological data for the sensitivity of the eye. This algorithm also accounts for the transmission of the atmosphere and the telescope, the brightness of the sky, the color of the star, the age of the observer, the aperture, and the magnification. (2) Second, 314 observed values for the limiting magnitude were collected as a test of the formula. It is found that the formula does accurately predict the average observed limiting magnitudes under all conditions.

  18. Telescopes of galileo.

    PubMed

    Greco, V; Molesini, G; Quercioli, F

    1993-11-01

    The Florentine Istituto e Museo di Storia delta Scienza houses two complete telescopes and a single objective lens (reconstructed from several fragments) that can be attributed to Galileo. These optics have been partially dismantled and made available for optical testing with state-of-the-art equipment. The lenses were investigated individually; the focal length and the radii of curvature were measured, and the optical layout of the instruments was worked out. The optical quality of the surfaces and the overall performance of the two complete telescopes have been evaluated interferometrically at a wavelength of 633 nm (with a He-Ne laser source). It was found in particular that the optics of Galileo came close to attaining diffraction-limited operation.

  19. Galileo's wondrous telescope

    NASA Astrophysics Data System (ADS)

    Cartlidge, Edwin

    2008-06-01

    If you need reminding of just how wrong the great and the good can be, take a trip to the Museum of the History of Science in Florence, Italy. The museum is staging an exhibition entitled "Galileo's telescope - the instrument that changed the world" to mark the 400th anniversary this year of Galileo Galilei's revolutionary astronomical discoveries, which were made possible by the invention of the telescope. At the start of the 17th century, astronomers assumed that all the planets and the stars in the heavens had been identified and that there was nothing new for them to discover, as the exhibition's curator, Giorgio Strano, points out. "No-one could have imagined what wondrous new things were about to be revealed by an instrument created by inserting two eyeglass lenses into the ends of a tube," he adds.

  20. Telescopic horizon scanning.

    PubMed

    Koenderink, Jan

    2014-12-20

    The problem of "distortionless" viewing with terrestrial telescopic systems (mainly "binoculars") remains problematic. The so called "globe effect" is only partially counteracted in modern designs. Theories addressing the phenomenon have never reached definitive closure. In this paper, we show that exact distortionless viewing with terrestrial telescopic systems is not possible in general, but that it is in principle possible in-very frequent in battle field and marine applications-the case of horizon scanning. However, this involves cylindrical optical elements. For opto-electronic systems, a full solution is more readily feasible. The solution involves a novel interpretation of the relevant constraints and objectives. For final design decisions, it is not necessary to rely on a corpus of psychophysical (or ergonomic) data, although one has to decide whether the instrument is intended as an extension of the eye or as a "pictorial" device.

  1. Nonmechanical bifocal zoom telescope.

    PubMed

    Valley, Pouria; Reza Dodge, Mohammad; Schwiegerling, Jim; Peyman, Gholam; Peyghambarian, N

    2010-08-01

    We report on a novel zoom lens with no moving parts in the form of a switchable Galilean telescope. This zoom telescope consists of two flat liquid-crystal diffractive lenses with apertures of 10mm that can each take on the focal lengths of -50 and +100cm, with a spacing of 50cm and, hence, a zoom ratio of 4x. The lenses are driven using a low-voltage ac source with 1.6V and exhibit millisecond switching times. The spectral characteristic of this diffractive zoom system is evaluated for light sources of various bandwidths. Potential applications for this technology include a zoom lens with no moving parts for camera phones and medical imaging devices.

  2. TAUVEX - UV Space Telescope

    NASA Astrophysics Data System (ADS)

    Topaz, Jeremy; Braun, Ofer; Brosch, Noah

    1993-01-01

    The TAUVEX UV Space Telescope currently under construction by El-Op Ltd. in Israel is designed both for recording images of the sky in the UV region and to serve as the optical monitor for the SODART X-Ray Telescope being built by the Danish Space Research Institute. The two systems, together with several other experiments, will be flown on the S-R-G satellite to be launched by the CIS in 1995. TAUVEX will image a field of about 1 deg simultaneously in three spectral bands. In addition, it will record a selected object in a high-speed time-resolved mode in these bands. The concept and design of TAUVEX is described in this paper.

  3. The Neutrino Telescope ANTARES

    NASA Astrophysics Data System (ADS)

    Hernández, Juan José

    Neutrinos can reveal a brand new Universe at high energies. The ANTARES collaboration [1] , formed in 1996, works towards the building and deployment of a neutrino telescope. This detector could observe and study high energy astrophysical sources such as X-ray binary systems, young supernova remnants or Active Galactic Nuclei and help to discover or set exclusion limits on some of the elementary particles and objects that have been put forward as candidates to fill the Universe (WIMPS, neutralinos, topological deffects, Q-balls, etc). A neutrino telescope will certainly open a new observational window and can shed light on the most energetic phenomena of the Universe. A review of the progress made by the ANTARES collaboration to achieve this goal is presented

  4. A New Generation of Sub Mm Telescopes, Made of Carbon Fiber Reinforced Plastic

    NASA Technical Reports Server (NTRS)

    Mezger, P.; Baars, J. W. M.; Ulich, B. L.

    1984-01-01

    Carbon fiber reinforced plastic (CFRP) appears to be the material most suited for the construction of submillimeter telescopes (SMT) not only for ground-based use but also for space applications. The accuracy of the CFRP reflectors needs to be improved beyond value of the 17 micron rms envisaged for the 10 m SMT.

  5. [Galileo and his telescope].

    PubMed

    Strebel, Christoph

    2006-01-01

    Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book.

  6. The Large Area Telescope

    SciTech Connect

    Michelson, Peter F.; /KIPAC, Menlo Park /Stanford U., HEPL

    2007-11-13

    The Large Area Telescope (LAT), one of two instruments on the Gamma-ray Large Area Space Telescope (GLAST) mission, is an imaging, wide field-of-view, high-energy pair-conversion telescope, covering the energy range from {approx}20 MeV to more than 300 GeV. The LAT is being built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. The scientific objectives the LAT will address include resolving the high-energy gamma-ray sky and determining the nature of the unidentified gamma-ray sources and the origin of the apparently isotropic diffuse emission observed by EGRET; understanding the mechanisms of particle acceleration in celestial sources, including active galactic nuclei, pulsars, and supernovae remnants; studying the high-energy behavior of gamma-ray bursts and transients; using high-energy gamma-rays to probe the early universe to z {ge} 6; and probing the nature of dark matter. The components of the LAT include a precision silicon-strip detector tracker and a CsI(Tl) calorimeter, a segmented anticoincidence shield that covers the tracker array, and a programmable trigger and data acquisition system. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large field-of-view and ensuring that nearly all pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. This paper includes a description of each of these LAT subsystems as well as a summary of the overall performance of the telescope.

  7. Hubble Space Telescope satellite

    NASA Technical Reports Server (NTRS)

    Mitchell, R. E.

    1985-01-01

    The Hubble Space Telescope, named for the American astronomer Edwin Powell Hubble, will be the largest and most powerful astronomical instrument ever orbited. Placed above the obscuring effects of the earth's atmosphere in a 600-km orbit, this remotely-controlled, free-flying satellite observatory will expand the terrestrial-equivalent resolution of the universe by a factor of seven, or a volumetric factor of 350. This telescope has a 2.4-m primary mirror and can accommodate five scientific instruments (cameras, spectrographs and photometers). The optics are suitable for a spectral range from 1100 angstrom to 1 mm wavelength. With a projected service life of fifteen years, the spacecraft can be serviced on-orbit for replacement of degraded systems, to insert advanced scientific instruments, and to reboost the telescope from decayed altitudes. The anticipated image quality will be a result of extremely precise lambda/20 optics, stringent cleanliness, and very stable pointing: jitter will be held to less than 0.01 arcsecond for indefinite observation periods, consistent with instrument apertures as small as 0.1 arcsecond.

  8. Lessons learned with the Active Phasing Experiment: comparison of four optical phasing sensors on a segmented Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Gonte, F.; Surdej, I.

    The adaptive optics capabilities are strongly limited by the quality of the phasing of the primary mirror of the extremely large telescope. Up to date, the Keck telescopes are the only segmented telescope phased with a quality enabling the application of adaptive optics. The Active Phasing Experiment has been installed at the Namyth focus of the Very Large Telescope Melipal during the last 6 months. Its purpose is to understand and compare different technological concepts for an optical phasing sensor dedicated to the European Extremely Large Telescope. The pupil of the telescope is segmented in 61 hexagonal segments by projecting it on an Active Segmented Mirror. The ASM is controlled by a dual wavenlength interferometer made by Fogale Nanotech with a nanometric precision. The segmented pupil is distributed in parallel to four optical phasing sensors. They are a pyramid sensor, a curvature sensor, a phase filtering sensor and a ShackHartmann sensor. They have been developed respectively by Istituto Nazionale di Astrofisica in Florenze, Instituto Astrofisica Canarias in Tenerife, Laboratoire d'Astrophysique de Marseille and ESO. The global behaviour of the optical phasing sensors will be described and preliminary results of the Active Phasing Experiments obtained on sky will be explained. The extrapolation of the results to the EELT and the potential consequences for the adaptive optics will be given. The Active Phasing Experiment has been financed by the European Union and the European Southern Observatory via the Sixth European Union Framework Program for Research and Technological Development under the contract number 011863.

  9. NASA Telescopes Help Identify Most Distant Galaxy Cluster

    NASA Astrophysics Data System (ADS)

    2011-01-01

    WASHINGTON -- Astronomers have uncovered a burgeoning galactic metropolis, the most distant known in the early universe. This ancient collection of galaxies presumably grew into a modern galaxy cluster similar to the massive ones seen today. The developing cluster, named COSMOS-AzTEC3, was discovered and characterized by multi-wavelength telescopes, including NASA's Spitzer, Chandra and Hubble space telescopes, and the ground-based W.M. Keck Observatory and Japan's Subaru Telescope. "This exciting discovery showcases the exceptional science made possible through collaboration among NASA projects and our international partners," said Jon Morse, NASA's Astrophysics Division director at NASA Headquarters in Washington. Scientists refer to this growing lump of galaxies as a proto-cluster. COSMOS-AzTEC3 is the most distant massive proto-cluster known, and also one of the youngest, because it is being seen when the universe itself was young. The cluster is roughly 12.6 billion light-years away from Earth. Our universe is estimated to be 13.7 billion years old. Previously, more mature versions of these clusters had been spotted at 10 billion light-years away. The astronomers also found that this cluster is buzzing with extreme bursts of star formation and one enormous feeding black hole. "We think the starbursts and black holes are the seeds of the cluster," said Peter Capak of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena. "These seeds will eventually grow into a giant, central galaxy that will dominate the cluster -- a trait found in modern-day galaxy clusters." Capak is first author of a paper appearing in the Jan. 13 issue of the journal Nature. Most galaxies in our universe are bound together into clusters that dot the cosmic landscape like urban sprawls, usually centered around one old, monstrous galaxy containing a massive black hole. Astronomers thought that primitive versions of these clusters, still forming and clumping

  10. Shack-Hartmann mask/pupil registration algorithm for wavefront sensing in segmented mirror telescopes.

    PubMed

    Piatrou, Piotr; Chanan, Gary

    2013-11-10

    Shack-Hartmann wavefront sensing in general requires careful registration of the reimaged telescope primary mirror to the Shack-Hartmann mask or lenslet array. The registration requirements are particularly demanding for applications in which segmented mirrors are phased using a physical optics generalization of the Shack-Hartmann test. In such cases the registration tolerances are less than 0.1% of the diameter of the primary mirror. We present a pupil registration algorithm suitable for such high accuracy applications that is based on the one used successfully for phasing the segments of the Keck telescopes. The pupil is aligned in four degrees of freedom (translations, rotation, and magnification) by balancing the intensities of subimages formed by small subapertures that straddle the periphery of the mirror. We describe the algorithm in general terms and then in the specific context of two very different geometries: the 492 segment Thirty Meter Telescope, and the seven "segment" Giant Magellan Telescope. Through detailed simulations we explore the accuracy of the algorithm and its sensitivity to such effects as cross talk, noise/counting statistics, atmospheric scintillation, and segment reflectivity variations.

  11. PROPER MOTIONS OF THE ARCHES CLUSTER WITH KECK LASER GUIDE STAR ADAPTIVE OPTICS: THE FIRST KINEMATIC MASS MEASUREMENT OF THE ARCHES

    SciTech Connect

    Clarkson, W. I.; Ghez, A. M.; Morris, M. R.; Yelda, S.; Lu, J. R.; Stolte, A.; McCrady, N.; Do, T.

    2012-06-01

    mass estimates assuming a globally top-heavy or strongly truncated present-day mass function (PDMF; with {Gamma} {approx} 0.6) yield mass estimates closer to M(R < 0.4 pc) {approx} 1-1.2 Multiplication-Sign 10{sup 4} M{sub Sun }. Consequently, our results support a PDMF that is either top-heavy or truncated at low mass, or both. Collateral benefits of our data and analysis include: (1) cluster membership probabilities, which may be used to extract a clean-cluster sample for future photometric work; (2) a refined estimate of the bulk motion of the Arches cluster with respect to the field, which we find to be 172 {+-} 15 km s{sup -1}, which is slightly slower than suggested by previous measurements using one epoch each with the Very Large Telescope and the Keck telescope; and (3) a velocity dispersion estimate for the field itself, which is likely dominated by the inner Galactic bulge and the nuclear disk.

  12. KECK SPECTROSCOPY OF FAINT 3 < z < 7 LYMAN BREAK GALAXIES. III. THE MEAN ULTRAVIOLET SPECTRUM AT z {approx_equal} 4

    SciTech Connect

    Jones, Tucker; Ellis, Richard S.; Stark, Daniel P.

    2012-05-20

    We present and discuss the mean rest-frame ultraviolet spectrum for a sample of 81 Lyman break galaxies (LBGs) selected to be B-band dropouts at z {approx_equal} 4. The sample is mostly drawn from our ongoing Keck/DEIMOS survey in the GOODS fields and augmented with archival Very Large Telescope data. In general, we find similar spectroscopic trends to those found in earlier surveys of LBGs at z = 3. Specifically, low-ionization absorption lines which trace neutral outflowing gas are weaker in galaxies with stronger Ly{alpha} emission, bluer UV spectral slopes, lower stellar masses, lower UV luminosities, and smaller half-light radii. This is consistent with a physical picture whereby star formation drives outflows of neutral gas which scatter Ly{alpha} and produce strong low-ionization absorption lines, while increasing galaxy stellar mass, size, metallicity, and dust content. Typical galaxies are thus expected to have stronger Ly{alpha} emission and weaker low-ionization absorption at earlier times, and we indeed find somewhat weaker low-ionization absorption at higher redshifts. In conjunction with earlier results from our survey, we argue that the reduced low-ionization absorption is likely caused by lower covering fraction and/or velocity range of outflowing neutral gas at earlier epochs. Although low-ionization absorption decreases at higher redshift, fine-structure emission lines are stronger, suggesting a greater concentration of neutral gas at small galactocentric radius ({approx}< 5 kpc). Our continuing survey will enable us to extend these diagnostics more reliably to higher redshift and determine the implications for the escape fraction of ionizing photons which governs the role of early galaxies in cosmic reionization.

  13. A Newly Developed Model for Fluorescence of C2H6 ν5 in Comets and Application to Infrared Spectra Acquired with NIRSPEC at Keck II

    NASA Astrophysics Data System (ADS)

    Radeva, Yana L.; Mumma, M. J.; Villanueva, G. L.; A'Hearn, M. F.

    2010-01-01

    Exploring the compositional diversity of cometary nuclei is key to understanding the formation and evolution of the Solar System, and the origin of water and prebiotic organics on the Earth. For most polyatomic gases, a production rate can be obtained from measured ro-vibrational intensities if an accurate rotational temperature is available, and the comparison of temperatures displayed by individual molecular species can reveal additional insights into physics in the cometary inner coma. Until now, accurate temperatures could be derived for HCN, CO, and H2O, but not for ethane (C2H6). As a symmetric hydrocarbon, C2H6 is uniquely sampled in the infrared, but the fine rotational structure of the ν7 Q-branches at 3.3 μm cannot be resolved by current infrared spectrometers, ultimately limiting the retrievals of rotational temperatures from these lines. However, the complex ro-vibrational structure (P- and R-branches) of the ν5 band at 3.5 μm is resolved by the Near Infrared Echelle Spectrograph on the Keck II telescope (NIRSPEC). We developed a fluorescence model for the infrared ν5 band of C2H6, and applied it to interpret high-resolution infrared spectra acquired with NIRSPEC. We present rotational temperatures and production rates for C2H6 in multiple comets. We compare the extracted rotational temperatures for ethane with those obtained from simultaneous measurements of other species (H2O and HCN). We also compare mixing ratios derived from the C2H6 ν5 band with those derived from the previously analyzed (by NASA GSFC team members) ν7 band. This work now establishes a robust method for quantifying additional physical parameters for ethane in comets.

  14. The Matryoshka Disk: Keck/NIRC2 Discovery of a Solar-system-scale, Radially Segregated Residual Protoplanetary Disk around HD 141569A

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Grady, Carol A.; Cloutier, Ryan; Konishi, Mihoko; Stassun, Keivan; Debes, John; van der Marel, Nienke; Muto, Takayuki; Jayawardhana, Ray; Ratzka, Thorsten

    2016-03-01

    Using Keck/NIRC2 {L}\\prime (3.78 μm) data, we report the direct imaging discovery of a scattered-light-resolved, solar-system-scale residual protoplanetary disk around the young A-type star HD 141569A, interior to and concentric with the two ring-like structures at wider separations. The disk is resolved down to ∼0.″25 and appears as an arc-like rim with attached hook-like features. It is located at an angular separation intermediate between that of warm CO gas identified from spatially resolved mid-infrared spectroscopy and diffuse dust emission recently discovered with the Hubble Space Telescope. The inner disk has a radius of ∼39 au, a position angle consistent with north up, and an inclination of i ∼ 56o and has a center offset from the star. Forward modeling of the disk favors a thick torus-like emission sharply truncated at separations beyond the torus’s photocenter and heavily depleted at smaller separations. In particular, the best-fit density power law for the dust suggests that the inner disk dust and gas (as probed by CO) are radially segregated, a feature consistent with the dust trapping mechanism inferred from observations of “canonical” transitional disks. However, the inner disk component may instead be explained by radiation pressure-induced migration in optically thin conditions, in contrast to the two stellar companion/planet-influenced ring-like structures at wider separations. HD 141569A’s circumstellar environment—with three nested, gapped, concentric dust populations—is an excellent laboratory for understanding the relationship between planet formation and the evolution of both dust grains and disk architecture.

  15. Comparing NEO Search Telescopes

    NASA Astrophysics Data System (ADS)

    Myhrvold, Nathan

    2016-04-01

    Multiple terrestrial and space-based telescopes have been proposed for detecting and tracking near-Earth objects (NEOs). Detailed simulations of the search performance of these systems have used complex computer codes that are not widely available, which hinders accurate cross-comparison of the proposals and obscures whether they have consistent assumptions. Moreover, some proposed instruments would survey infrared (IR) bands, whereas others would operate in the visible band, and differences among asteroid thermal and visible-light models used in the simulations further complicate like-to-like comparisons. I use simple physical principles to estimate basic performance metrics for the ground-based Large Synoptic Survey Telescope and three space-based instruments—Sentinel, NEOCam, and a Cubesat constellation. The performance is measured against two different NEO distributions, the Bottke et al. distribution of general NEOs, and the Veres et al. distribution of Earth-impacting NEO. The results of the comparison show simplified relative performance metrics, including the expected number of NEOs visible in the search volumes and the initial detection rates expected for each system. Although these simplified comparisons do not capture all of the details, they give considerable insight into the physical factors limiting performance. Multiple asteroid thermal models are considered, including FRM, NEATM, and a new generalized form of FRM. I describe issues with how IR albedo and emissivity have been estimated in previous studies, which may render them inaccurate. A thermal model for tumbling asteroids is also developed and suggests that tumbling asteroids may be surprisingly difficult for IR telescopes to observe.

  16. The Planck Telescope reflectors

    NASA Astrophysics Data System (ADS)

    Stute, Thomas

    2004-09-01

    The mechanical division of EADS-Astrium GmbH, Friedrichshafen is currently engaged with the development, manufacturing and testing of the advanced dimensionally stable composite reflectors for the ESA satellite borne telescope Planck. The objective of the ESA mission Planck is to analyse the first light that filled the universe, the cosmic microwave background radiation. Under contract of the Danish Space Research Institute and ESA EADS-Astrium GmbH is developing the all CFRP primary and secondary reflectors for the 1.5-metre telescope which is the main instrument of the Planck satellite. The operational frequency ranges from to 25 GHz to 1000 GHz. The demanding high contour accuracy and surface roughness requirements are met. The design provides the extreme dimensional stability required by the cryogenic operational environment at around 40 K. The elliptical off-axis reflectors display a classical lightweight sandwich design with CFRP core and facesheets. Isostatic mounts provide the interfaces to the telescope structure. Protected VDA provides the reflecting surface. The manufacturing is performed at the Friedrichshafen premises of EADS-Space Transportation GmbH, the former Dornier composite workshops. Advanced manufacturing technologies like true angle lay-up by CNC fibre placement and filament winding are utilized. The protected coating is applied at the CAHA facilities at the Calar Alto Observatory, Spain. The exhaustive environmental testing is performed at the facilities of IABG, Munich (mechanical testing) and for the cryo-optical tests at CSL Liege. The project is in advanced state with both Qualification Models being under environmental testing. The flight models will be delivered in 2004. The paper gives an overview over the requirements and the main structural features how these requirements are met. Special production aspects and available test results are reported.

  17. Is Your Telescope Tweeting?

    NASA Astrophysics Data System (ADS)

    Atkinson, Nancy

    2009-05-01

    Half of the world's population today was born after the Apollo Moon landings. The best way to reach this generation and get them excited about today's space exploration and astronomy news and events is through online social media, which are technologies that allow anyone to communicate with everyone. Twitter is a growing popular social media tool that uses short, 140 character "Tweets" to quickly and concisely convey updates on what you "are doing." With the right combination of information, personality and fun, telescopes and spacecraft are using Twitter for public outreach, providing important status updates while making the public feel like they are part of the mission.

  18. SST dual-mirror telescopes for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Dumas, Delphine; Laporte, Philippe; Sol, Hélène; Pareschi, Giovanni; Canestrari, Rodolfo; Stringhetti, Luca; Catalano, Osvaldo; White, Richard; Greenshaw, Tim; Hinton, Jim; Blake, Simon

    2014-07-01

    The Cherenkov Telescope Array (CTA) is an international collaboration that aims to create the world's foremost very high energy gamma-ray observatory, composed of large, medium and small size telescopes (SST). The SSTs will be the most numerous telescopes on site and will focus on capturing the rarer highest energy photons. Three prototypes of SST are designed and currently under construction; two of them, ASTRI and SST-GATE, have been designed, based on a dual-mirror Schwarzschild-Couder (SC) design which has never been built before for any astronomical observation. The SC optical design allows for a small plate scale, a wide field of view and a lightweight cameras aiming to minimize the cost of SST telescopes in order to increase their number in the array. The aim of this article is to report the progress of the two telescope projects prototyping telescope structures and cameras for the Small Size Telescopes for CTA. After a discussion of the CTA project and its scientific objectives, the performance of the SC design is described, with focus on the specific designs of SST-GATE and ASTRI telescopes. The design of both prototypes and their progress is reported in the current prototyping phase. The designs of Cherenkov cameras, CHEC and ASTRI, to be mounted on these telescopes are discussed and progresses are reported.

  19. High incidence of interleukin 10 mRNA but not interleukin 2 mRNA detected in human breast tumours.

    PubMed Central

    Venetsanakos, E.; Beckman, I.; Bradley, J.; Skinner, J. M.

    1997-01-01

    Despite the presence of a lymphocytic infiltrate in solid cancers, the failure for tumour growth to be contained suggests an inadequate immune response to the tumour. Poor cytotoxicity exerted by tumour-infiltrating lymphocytes (TILs) against tumour cells in vitro, combined with continued tumour growth in vivo, suggests deficiencies in TIL function or numbers. Various theories have been postulated to explain how tumour cells may escape immunosurveillance and control. One of the many hypotheses is the failure of production of cytokines, which are necessary for T cells to mediate their function. Thus, the expression of cytokine mRNA in human breast tumour sections was investigated by reverse transcriptase polymerase chain reaction (RT-PCR) with cytokine-specific primers. A relatively consistent finding was detection of interleukin (IL) 10 mRNA among the tumours. No IL-2 and little IL-4 mRNA was detected in the tumours. IL-6 and IL-10 mRNA was detected in only one and two of the normal breast tissues respectively. IL-2, IL-4 and tumour necrosis factor (TNF)-alpha mRNA was not detected in any of the normal breast tissues. The reduced function of TILs may be related to IL-10, which has known inhibitory effects on T-cell activation. Images Figure 1 PMID:9192989

  20. MeV electron acceleration at 1 kHz with <10 mJ laser pulses

    NASA Astrophysics Data System (ADS)

    Salehi, Fatholah; Goers, Andy; Hine, George; Feder, Linus; Kuk, Donghoon; Miao, Bo; Woodbury, Daniel; Kim, Ki-Yong; Milchberg, Howard

    2017-01-01

    We demonstrate laser driven acceleration of electrons to MeV-scale energies at 1 kHz repetition rate using <10 mJ pulses focused on near-critical density He and H2 gas jets. Using the H2 gas jet, electron acceleration to 0.5 MeV in 10 fC bunches was observed with laser pulse energy as low as 1.3 mJ. Increasing the pulse energy to 10 mJ, we measure 1pC charge bunches with >1 MeV energy for both He and H gas jets. Such a high repetition rate, high flux ultrafast source has immediate application to time resolved probing of matter for scientific, medical, or security applications, either using the electrons directly or using a high-Z foil converter to generate ultrafast γ-rays. This work is supported by the US Department of Energy, the National Science Foundation, and the Air Force Office of Scientific Research.

  1. Deep Uranus Cloud Structure and Methane Mixing Ratio as Constrained by Keck AO Imaging Observations.

    NASA Astrophysics Data System (ADS)

    Sromovsky, Lawrence A.; Fry, P. M.

    2006-09-01

    Keck AO imaging of Uranus in 2004 with H and H-continuum filters provide deep views of scattered light in the Uranian atmosphere with different sensitivities to methane absorption and collision-induced absorption by Hydrogen. After deconvolution, these images provide accurate low-latitude center-to-limb (east-west) profiles out to view angles of nearly 80 degrees, permitting solutions for both cloud properties and the methane mixing ratio. After accounting for a very small high-altitude haze contribution, the observed central disk I/F values for H and H-continuum filters can be modeled using an opaque semi-infinite cloud of very low albedo (near 0.04), a broken cloud of high albedo (fractional coverage near 0.04-.06), or a continuous cloud of low optical depth (0.2-1.0) containing particles of high single-scattering albedo. For low methane mixing ratios (0.5-1 percent) the central disk I/F values require a deep cloud (near 8 bars), while for the high methane mixing ratios (2-4 percent) a higher altitude solution is possible (near 3 bars). However, the observed slightly limb-brightened and relatively flat center-to-limb H-continuum profile is only consistent with an optically thin cloud. The best-fit solution is a low methane mixing ratio (0.75-1.0 percent vmr), and a deep low opacity cloud (optical depth ranging from 0.2 to 0.4 for scattering asymmetry parameters ranging from 0 to 0.3). This CH4 mixing ratio is slightly below the lower limit of the Baines et al. (1995, Icarus 114, 328-340) result of 1.6(+0.7/-0.5) percent. This work was supported by NASA's Planetary Astronomy and Planetary Atmospheres programs and the W.M. Keck Observatory. We thank those of Hawaiian ancestry whose generous hospitality in allowing use of their sacred mountain made the observations possible.

  2. SNAP Telescope Latest Developments

    NASA Astrophysics Data System (ADS)

    Lampton, M.; SNAP Collaboration

    2004-12-01

    The coming era of precision cosmology imposes new demands on space telescopes with regard to spectrophotometric accuracy and image stability. To meet these requirements for SNAP we have developed an all reflecting two-meter-class space telescope of the three-mirror anastigmat type. Our design features a large flat annular field (1.5 degrees = 580mm diameter) and a telephoto advantage of 6, delivering a 22m focal length within an optical package length of only 3.5 meters. The use of highly stable materials (Corning ULE glass and carbon-fiber reinforced cyanate ester resin for the metering structure) combined with agressive distributed thermal control and an L2 orbit location will lead to unmatched figure stability. Owing to our choice of rigid structure with nondeployable solar panels, finite-element models show no structural resonances below 10Hz. An exhaustive stray light study has been completed. Beginning in 2005, two industry studies will develop plans for fabrication, integration and test, bringing SNAP to a highly realistic level of definition. SNAP is supported by the Office of Science, US DoE, under contract DE-AC03-76SF00098.

  3. The CCAT Telescope

    NASA Astrophysics Data System (ADS)

    Glenn, Jason; CCAT

    2013-01-01

    CCAT will be a 25 m diameter on-axis Gregory telescope operating in the 0.2 to 2.1 mm wavelength range. It will be located at an altitude of 5600 m on Cerro Chajnantor in northern Chile. CCAT will support cameras and spectrometers with up to 1 field of view at its f/6 Nasmyth foci. The key performance requirements for the telescope are a half wavefront error <12.5 μm rms and pointing error <0.35"/350 μm). CCAT will have an f/0.4 primary with an active surface to compensate gravitational and thermal deformations. The primary will be made of 2 m keystone-shaped segments, each with 16 machined aluminum tiles mounted on a carbon-fiber-reinforced-plastic (CFRP) subframe. The segments will be supported by a CFRP spaceframe truss on an elevation over azimuth mount made of steel. CCAT will be inside an enclosure to reduce wavefront and pointing errors due to wind forces and thermal deformation due to solar illumination.

  4. The Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Jewell, P. R.

    1999-12-01

    The Green Bank Telescope The 100-m NRAO Green Bank Telescope will be completed in early 2000. The GBT has a large number of unique design and performance features that will give it unprecedented scientific capability. This poster display will review those features, which include an offset feed (clear aperture) design, an active surface, a closed-loop laser metrology system for surface figure and pointing control, broad frequency coverage from 100 MHz to 115 GHz, a versatile receiver selection mechanism, and a new multi-input, 256k-channel autocorrelation spectrometer. The status of the project, the commissioning schedule, plans for early operations, the initial instrumentation suite, and plans for future instrumentation will be reviewed. Scientific areas for which the GBT will have a large impact will be discussed, including observations of young galaxies at extreme redshifts, pulsars, HI and molecular spectroscopy, VLBI work, and millimeter-wave spectroscopy and continuum studies. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  5. Magellan Telescopes operations 2008

    NASA Astrophysics Data System (ADS)

    Osip, David J.; Phillips, Mark M.; Palunas, Povilas; Perez, Frank; Leroy, M.

    2008-07-01

    The twin 6.5m Magellan Telescopes have been in routine operations at the Las Campanas Observatory in the Chilean Andes since 2001 and 2002 respectively. The telescopes are owned and operated by Carnegie for the benefit of the Magellan consortium members (Carnegie Institution of Washington, Harvard University, the University of Arizona, Massachusetts Institute of Technology, and the University of Michigan). This paper provides an up to date review of the scientific, technical, and administrative structure of the 'Magellan Model' for observatory operations. With a modest operations budget and a reasonably small staff, the observatory is operated in the "classical" mode, wherein the visiting observer is a key member of the operations team. Under this model, all instrumentation is supplied entirely by the consortium members and the various instrument teams continue to play a critical support role beyond initial deployment and commissioning activities. Here, we present a critical analysis of the Magellan operations model and suggest lessons learned and changes implemented as we continue to evolve an organizational structure that can efficiently deliver a high scientific return for the investment of the partners.

  6. CHANDRA, KECK, AND VLA OBSERVATIONS OF THE CRAB NEBULA DURING THE 2011-APRIL GAMMA-RAY FLARE

    SciTech Connect

    Weisskopf, Martin C.; Tennant, Allyn F.; O'Dell, Stephen L.; Arons, Jonathan; Blandford, Roger; Funk, Stefan; Romani, Roger W.; Buehler, Rolf; Caraveo, Patrizia; De Luca, Andrea; Cheung, Chi C.; Costa, Enrico; Ferrigno, Carlo; Fu, Hai; Habermehl, Moritz; Horns, Dieter; Linford, Justin D.; Lobanov, Andrei; Max, Claire; Mignani, Roberto; and others

    2013-03-01

    We present results from our analysis of Chandra X-Ray Observatory, W. M. Keck Observatory, and Karl G. Jansky Very Large Array (VLA) images of the Crab Nebula that were contemporaneous with the {gamma}-ray flare of 2011 April. Despite hints in the X-ray data, we find no evidence for statistically significant variations that pinpoint the specific location of the flares within the Nebula. The Keck observations extend this conclusion to the 'inner knot', i.e., the feature within an arcsecond of the pulsar. The VLA observations support this conclusion. We also discuss theoretical implications of the {gamma}-ray flares and suggest that the most dramatic {gamma}-ray flares are due to radiation-reaction-limited synchrotron emission associated with sudden, dissipative changes in the current system sustained by the central pulsar.

  7. Determining the amount of dust in the habitable zone: a Keck Nuller survey of 26 nearby main sequence stars

    NASA Astrophysics Data System (ADS)

    Mennesson, B.

    2010-10-01

    Because of contrast limitations at high angular resolution, direct observations of debris disks have so far been restricted to the outer (> 10AU) parts of nearby solar systems. The Keck Interferometer Nuller (KIN) was specifically designed to push this limit, and constrain exo-zodiacal emission originating from the "rocky planet forming region", i.e. from ∼0.1 AU to a few AUs. The characterization of exo-zodiacal light at these spatial scales is very revealing as it reflects the host system's specific distribution of planets, dust sources and sinks. Strong exo-zodi emission in the habitable zone is also important to identify, as it can be a hindrance to direct imaging of Earth-like exoplanets. We discuss here the results of a Keck Nuller exo-zodi program targeting 26 nearby main sequence stars, most of which with no previously known infrared excess.

  8. KECK SPECTROSCOPY OF FAINT 3 < z < 8 LYMAN BREAK GALAXIES: EVIDENCE FOR A DECLINING FRACTION OF EMISSION LINE SOURCES IN THE REDSHIFT RANGE 6 < z < 8

    SciTech Connect

    Schenker, Matthew A.; Ellis, Richard S.; Robertson, Brant E.; Stark, Daniel P.; Dunlop, James S.; McLure, Ross J.; Kneib, Jean-Paul; Richard, Johan

    2012-01-10

    Using deep Keck spectroscopy of Lyman break galaxies selected from infrared imaging data taken with the Wide Field Camera 3 on board the Hubble Space Telescope, we present new evidence for a reversal in the redshift-dependent fraction of star-forming galaxies with detectable Lyman alpha (Ly{alpha}) emission in the redshift range 6.3 < z < 8.8. Our earlier surveys with the DEIMOS spectrograph demonstrated a significant increase with redshift in the fraction of line emitting galaxies over the interval 4 < z < 6, particularly for intrinsically faint systems which dominate the luminosity density. Using the longer wavelength sensitivities of Low Resolution Imaging Spectrometer and NIRSPEC, we have targeted 19 Lyman break galaxies selected using recent WFC3/IR data whose photometric redshifts are in the range 6.3 < z < 8.8 and which span a wide range of intrinsic luminosities. Our spectroscopic exposures typically reach a 5{sigma} sensitivity of <50 A for the rest-frame equivalent width (EW) of Ly{alpha} emission. Despite the high fraction of emitters seen only a few hundred million years later, we find only two convincing and one possible line emitter in our more distant sample. Combining with published data on a further seven sources obtained using FORS2 on the ESO Very Large Telescope, and assuming continuity in the trends found at lower redshift, we discuss the significance of this apparent reversal in the redshift-dependent Ly{alpha} fraction in the context of our range in continuum luminosity. Assuming all the targeted sources are at their photometric redshift and our assumptions about the Ly{alpha} EW distribution are correct, we would expect to find so few emitters in less than 1% of the realizations drawn from our lower redshift samples. Our new results provide further support for the suggestion that, at the redshifts now being probed spectroscopically, we are entering the era where the intergalactic medium is partially neutral. With the arrival of more

  9. Simulation and analysis of laser guide star adaptive optics systems for the eight to ten meter class telescopes

    SciTech Connect

    Gavel, D.T.; Olivier, S.S.

    1994-03-01

    This paper discusses the design and analysis of laser-guided adaptive optic systems for the large, 8--10 meter class telescopes. We describe a technique for calculating the expected modulation transfer function and the point spread function for a closed loop adaptive optics system, parameterized by the degree of correction and the seeing conditions. The results agree closely with simulations and experimental data, and validate well known scaling law models even at low order correction. Scaling law.model analysis of a proposed adaptive optics system at the Keck telescope leads to the conclusion that a single laser guide star beacon will be adequate for diffraction limited imaging at wavelengths between 1 and 3 am with reasonable coverage of the sky. Cone anisoplanatism will dominate wavefront correction error at the visible wavelengths unless multiple laser guide stars are used.

  10. Near anastigmatic grazing incidence telescope

    NASA Technical Reports Server (NTRS)

    Korsch, D.

    1984-01-01

    A performance capability assessment is presently conducted for short versus long grazing incidence telescope designs, in view of the observation that the field curvature and astigmatism that are the primary residual aberrations of a Wolter-type incidence telescope can be substantially reduced through mirror length reduction. A major advantage of the short element telescope is that, if sufficiently short, both the paraboloid and hyperboloid surfaces may be fabricated as a single piece; this significantly facilitates the task of alignment.

  11. Cost Modeling for Space Telescope

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2011-01-01

    Parametric cost models are an important tool for planning missions, compare concepts and justify technology investments. This paper presents on-going efforts to develop single variable and multi-variable cost models for space telescope optical telescope assembly (OTA). These models are based on data collected from historical space telescope missions. Standard statistical methods are used to derive CERs for OTA cost versus aperture diameter and mass. The results are compared with previously published models.

  12. High-precision robotic equatorial C-ring telescope mounts: design, fabrication, and performance

    NASA Astrophysics Data System (ADS)

    Dubberley, Matthew A.

    2010-07-01

    The performance of the C-ring telescope mount rivals other designs in stiffness, tracking, simplicity, lack of field rotation, mechanical size and operating envelope. Issues relating to cost, fabrication, and complexity have suppressed the prevalence of the C-ring mount. The Las Cumbres Observatory Global Telescope (LCOGT) robotic C-ring telescope mounts, built for its network of 1.0m and 0.4m telescopes, solve many of these issues. The design yields a scalable mount with performance capabilities well suited for telescopes located at the best astronomical sites in the world at a low cost. Pointing has been demonstrated to be under 7 arc-sec RMS. Unguided tracking performance is 0.6 arc-sec for 1 minute and 2 arc-sec for 15 minutes. Slew speeds of 10deg/sec are reliably used with sub-second settling times. The mount coupled with the 1.0m telescope yields a well damped 16 Hz system. Axes are driven with zero backlash direct drive motors with a 0.01 arc-sec resolution. High system bandwidth yields superb disturbance rejection making it ideal for open air operation. Drive and bearings are maintenance free and feature a novel "bug cover" to seal them from wear and damage. Low costs are achieved with the drive/feedback configuration, structure design, and fabrication techniques, as well minimizing operating and maintenance.

  13. Water Vapor Measurement and Compensation in the Near and Mid-infrared with the Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Koresko, Chris D.; Colavita, Mark M.; Serabyn, Eugene; Booth, Andrew; Garcia, Jean I.

    2006-01-01

    A viewgraph presentation describing the methods, motivation and methods for water vapor measurement with the Keck interferometer near and mid infrared radiation band is shown. The topics include: 1) Motivation: Why measure H2O?; 2) Method: How do we measure H2O?; 3) Data: Phase and Group Delays for the K and N Bands; 4) Predicted and Actual Nband Phase and Dispersion; and 5) Validation of Atmospheric Turbulence Models with KI Data.

  14. Improving Undergraduate Research Experiences With An Intentional Mentoring Program: Lessons Learned Through Assessment of Keck Geology Consortium Programs

    NASA Astrophysics Data System (ADS)

    Wirth, K. R.; Garver, J. I.; Greer, L.; Pollock, M.; Varga, R. J.; Davidson, C. M.; Frey, H. M.; Hubbard, D. K.; Peck, W. H.; Wobus, R. A.

    2015-12-01

    The Keck Geology Consortium, with support from the National Science Foundation (REU Program) and ExxonMobil, is a collaborative effort by 18 colleges to improve geoscience education through high-quality research experiences. Since its inception in 1987 more than 1350 undergraduate students and 145 faculty have been involved in 189 yearlong research projects. This non-traditional REU model offers exceptional opportunities for students to address research questions at a deep level, to learn and utilize sophisticated analytical methods, and to engage in authentic collaborative research that culminates in an undergraduate research symposium and published abstracts volume. The large numbers of student and faculty participants in Keck projects also affords a unique opportunity to study the impacts of program design on undergraduate research experiences in the geosciences. Students who participate in Keck projects generally report significant gains in personal and professional dimensions, as well as in clarification of educational and career goals. Survey data from student participants, project directors, and campus advisors identify mentoring as one of the most critical and challenging elements of successful undergraduate research experiences. Additional challenges arise from the distributed nature of Keck projects (i.e., participants, project directors, advisors, and other collaborators are at different institutions) and across the span of yearlong projects. In an endeavor to improve student learning about the nature and process of science, and to make mentoring practices more intentional, the Consortium has developed workshops and materials to support both project directors and campus research advisors (e.g., best practices for mentoring, teaching ethical professional conduct, benchmarks for progress, activities to support students during research process). The Consortium continues to evolve its practices to better support students from underrepresented groups.

  15. Modular Orbital Demonstration of an Evolvable Space Telescope

    NASA Astrophysics Data System (ADS)

    Baldauf, Brian

    2016-06-01

    The key driver for a telescope's sensitivityis directly related to the size of t he mirror area that collects light from the objects being observed.The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The HDST envisioned for this mission would have an aperture >10 m, which is a larger payload than can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. The Optical Telescope Assembly for HDST is a primary mission cost driver. Enabling affordable solutions for this next generation of large aperture space-based telescope are needed.This reports on the concept for the MODEST, which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, a testbed for new instruments, and a tool for student's exploration of space. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Ceramic Matrix Composite that have excellent mechanical and thermal properties, e.g. high stiffness, high thermal conductivity, and low thermal expansion. It has been demonstrated

  16. High Resolution Optical Spectroscopy of Rosetta Target 67P/Churyumov-Gerasimenko Using Keck HIRES

    NASA Astrophysics Data System (ADS)

    McKay, Adam; Cochran, Anita L.; Bodewits, Dennis; A'Hearn, Michael F.; Altwegg, Kathrin; Gulkis, Samuel; Snodgrass, Colin; de Val-Borro, Miguel; Kelley, Michael S.; Feaga, Lori M.; Wooden, Diane H.; Bauer, James M.; Kramer, Emily A.

    2016-10-01

    We present high spectral resolution optical spectroscopy of Rosetta target 67P/Churyumov-Gerasimenko obtained on UT Dec 26 and 27, 2015 using the HIRES instrument on Keck I when the comet was at a heliocentric distance of approximately 2 AU post-perihelion. The spectra cover a spectral range of 3500-10000 Angstroms at a spectral resolution of 67,000. These observations aim to provide high spectral resolution, large projected field of view context for the high spatial resolution and small projected field of view observations obtained from the Rosetta instrument suite. We report detections of CN, NH2, and [OI] emission. From the [OI]6300 emission we derive a water production rate of approximately 2 x 1027 mol/s. Production rates (or upper limits) for other species will be presented and placed in context with recent results from Rosetta. We will also present results pertaining to the [OI]5577 line, which combined with the [OI]6300 emission can be used as a proxy for CO2. We will compare our results to observations obtained by Rosetta as well as NEOWISE and Spitzer.

  17. Evaluating the compliance of Keck's LGSAO automated aircraft protection system with FAA adopted criteria

    NASA Astrophysics Data System (ADS)

    Stomski, Paul J.; Campbell, Randy; Murphy, Thomas W.

    2014-07-01

    The W. M. Keck Observatory (WMKO) applied for and received a determination of no-objection from the Federal Aviation Administration (FAA) for laser guide star adaptive optics (LGS-AO) operations using an automated aircraft protection system (APS) in late 2013. WMKO's APS, named AIRSAFE, uses transponder based aircraft detection (TBAD) to replace human aircraft spotters. The FAA required WMKO to self-certify AIRSAFE compliance with SAE Aerospace Standard 6029A: "Performance Criteria for Laser Control Measures Used for Aviation Safety"[1] (AS- 6029A). AS-6029A prescribes performance and administrative criteria for an APS; essentially, requiring AIRSAFE to adequately protect all types of aircraft, traveling at any speed, altitude, distance and direction reasonably expected in the operating environment. A description of the analysis that comprises this compliance evaluation is the main focus of this paper. Also discussed is the AIRSAFE compliance with AS-6029A administrative criteria that includes characterization of site specific air traffic, failure modes, limitations, operating procedures, preventative maintenance procedures, and periodic system test procedures.

  18. A search for lithium in Pleiades brown dwarf candidates using the Keck hires echelle

    NASA Technical Reports Server (NTRS)

    Marcy, Geoffrey W.; Basri, Gibor; Graham, James R.

    1994-01-01

    We report Keck Observatory high-resolution echelle spectra of lithium at 670.8 nm in two of the lowest luminosity brown dwarf candidates in the Pleiades. These objects have estimated masses of 0.055 to 0.059 solar mass from their location on a color-magnitude diagram relative to theoretical isochrones. Stellar interior models predict that Li has not burned in them. However, we find no evidence of the Li line, at limits 100 to 1000 times below the initial abundance. This indicates that Li has in fact been depleted, presumably by nuclear processing as occurs in Pleiades stars. Interior models suggest that such large Li depletion occurs only for objects with M greater than 0.09 solar mass at the age of the Pleiades. Thus, it is unlikely that the candidates are brown dwarfs. The brown dwarf candidates present a conflict: either they have masses greater than suggested from their placement on the H-R diagram, or they do have the very low suggested masses but are nonetheless capable of destroying Li, in only 70 Myr. Until this dilemma is resolved, the photometric identification of brown dwarfs will remain difficult. Resolution may reside in higher T(sub eff) derived from optical and IR colors or in lower T(sub eff) in the interior models.

  19. Antenna-coupled TES bolometer arrays for BICEP2/Keck and SPIDER

    NASA Astrophysics Data System (ADS)

    Orlando, A.; Aikin, R. W.; Amiri, M.; Bock, J. J.; Bonetti, J. A.; Brevik, J. A.; Burger, B.; Chattopadthyay, G.; Day, P. K.; Filippini, J. P.; Golwala, S. R.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Irwin, K. D.; Kenyon, M.; Kovac, J. M.; Kuo, C. L.; Lange, A. E.; LeDuc, H. G.; Llombart, N.; Nguyen, H. T.; Ogburn, R. W.; Reintsema, C. D.; Runyan, M. C.; Staniszewski, Z.; Sudiwala, R.; Teply, G.; Trangsrud, A. R.; Turner, A. D.; Wilson, P.

    2010-07-01

    BICEP2/Keck and SPIDER are cosmic microwave background (CMB) polarimeters targeting the B-mode polarization induced by primordial gravitational waves from inflation. They will be using planar arrays of polarization sensitive antenna-coupled TES bolometers, operating at frequencies between 90 GHz and 220 GHz. At 150 GHz each array consists of 64 polarimeters and four of these arrays are assembled together to make a focal plane, for a total of 256 dual-polarization elements (512 TES sensors). The detector arrays are integrated with a time-domain SQUID multiplexer developed at NIST and read out using the multi-channel electronics (MCE) developed at the University of British Columbia. Following our progress in improving detector parameters uniformity across the arrays and fabrication yield, our main effort has focused on improving detector arrays optical and noise performances, in order to produce science grade focal planes achieving target sensitivities. We report on changes in detector design implemented to optimize such performances and following focal plane arrays characterization. BICEP2 has deployed a first 150 GHz science grade focal plane to the South Pole in December 2009.

  20. RESOLVING GAS FLOWS IN THE ULTRALUMINOUS STARBURST IRAS 23365+3604 WITH KECK LGSAO/OSIRIS

    SciTech Connect

    Martin, Crystal L.; Soto, Kurt T.

    2016-03-01

    Keck OSIRIS/LGSAO observations of the ultraluminous galaxy IRAS 23365+3604 resolve a circumnuclear bar (or irregular disk) of semimajor axis 0.″42 (520 pc) in Paα emission. The line-of-sight velocity of the ionized gas increases from the northeast toward the southwest; this gradient is perpendicular to the photometric major axis of the infrared emission. Two pairs of bends in the zero-velocity line are detected. The inner bend provides evidence for gas inflow onto the circumnuclear disk/bar structure. We interpret the gas kinematics on kiloparsec scales in relation to the molecular gas disk and multiphase outflow discovered previously. In particular, the fast component of the ouflow (detected previously in line wings) is not detected, adding support to the conjecture that the fast wind originates well beyond the nucleus. These data directly show the dynamics of gas inflow and outflow in the central kiloparsec of a late-stage, gas-rich merger and demonstrate the potential of integral field spectroscopy to improve our understanding of the role of gas flows during the growth phase of bulges and supermassive black holes.

  1. Confirmation of transiting Neptunes from HATNet and HATSouth using Keck/HIRES and Subaru/HDS

    NASA Astrophysics Data System (ADS)

    Bakos, Gaspar; Hartman, Joel D.; Bayliss, Daniel; Jordan, Andres; Sato, Bun'ei

    2014-02-01

    Wide-field photometric observations by the HATNet and HATSouth projects have identified ~ 1700 candidate transiting exoplanets (TEPs) around moderately bright stars (V ⪉ 14), leading to the publication of 49 TEPs, with many more confirmed planets undergoing analysis. Among the objects that we have identified are nine promising candidate transiting Neptunes. Only a handful of well- characterized Neptunes are known, and fewer still are known around bright stars, so it is imperative to confirm and characterize these candidates. Here we are proposing for 2 nights each on Keck/HIRES and Subaru/HDS (4 nights altogether) to confirm 6 of these candidate Neptunes. These are around moderately bright stars (V ≲ 13) and most have prior follow-up observations, including moderately high- precision RVs which place upper limits on the RV semiamplitudes ruling out hot Jupiters. If confirmed, these planets would represent a substantial increase in the number of well characterized Neptune-size planets with masses and radii measured to better than ~ 20% precision, and orbiting stars bright enough to permit further follow-up. We note that the HATSouth project is an equal collaboration between researchers in the US, Chile and Australia. For the Subaru/HDS component of this proposal, we request that the time allocation be split evenly between the NOAO, Chilean and Australian Gemini TACs.

  2. W.M. Keck-Vanderbilt Free-Electron Laser Center facilities

    NASA Astrophysics Data System (ADS)

    Gabella, William E.; Feng, Bibo; Kozub, John A.; Piston, David W.

    2002-04-01

    The W.M. Keck-Vanderbilt Free-electron Laser Center operates a reliable free-electron laser (FEL) that is used in human surgical trials, as well as in basic and applied sciences. The wavelength of the FEL is tunable from 2.1 micrometers to 9.6 micrometers , delivering above 50 mJ per macropulse with a repetition rate of 30 Hz. For soft tissue surgery, especially neurosurgery and surgery on the optic nerve, a wavelength of 6.45 micrometers has been found to ablate with little collateral damage. The free-electron laser beam is delivered to experiments approximately 2000 hours each year. The Center also supports several other tools useful for biomedical experiments: an optical parametric generator laser system with tunable wavelength similar to the free- electron laser except it has much lower average power; a Fourier transform infrared spectrometer to characterize samples; several devices for in vivo imaging including an optical coherence tomography setup, a two-photon fluorescent confocal microscope, and a cooled, integrating camera capable of imaging luciferin-luciferase reactions within the body of a mouse. The Center also houses a tunable, monochromatic x-ray source based on Compton backscattering of a laser off of a relativistic electron beam.

  3. Orbital Constraints on the (beta) Pic Inner Planet Candidate with Keck Adaptive Optics

    SciTech Connect

    Fitzgerald, M P; Kalas, P G; Graham, J R

    2009-09-23

    A point source observed 8AU in projection from {beta} Pictoris in L{prime} (3.8 {micro}m) imaging in 2003 has been recently presented as a planet candidate. Here we show the results of L{prime}-band adaptive optics imaging obtained at Keck Observatory in 2008. We do not detect {beta} Pic b beyond a limiting radius of 0.29-inch, or 5.5AU in projection, from the star. If {beta} Pic b is an orbiting planet, then it has moved {ge} 0.12-inch (2.4AU in projection) closer to the star in the five years separating the two epochs of observation. We examine the range of orbital parameters consistent with the observations, including likely bounds from the locations of previously inferred planetesimal belts. We find a family of low-eccentricity orbits with semimajor axes {approx} 8-9AU that are completely allowed, as well as a broad region of orbits with e {approx}< 0.2, a {approx}> 10AU that are allowed if the apparent motion of the planet was towards the star in 2003. We compare this allowed space with predictions of the planetary orbital elements from the literature. Additionally, we show how similar observations in the next several years can further constrain the space of allowed orbits. Non-detections of the source through 2013 will exclude the interpretation of the candidate as a planet orbiting between the 6.4 and 16AU planetesimal belts.

  4. Limits on entanglement effects in the string landscape from Planck and BICEP/Keck data

    NASA Astrophysics Data System (ADS)

    Kinney, William H.

    2016-11-01

    We consider observational limits on a proposed model of the string landscape in inflation. In this scenario, effects from the decoherence of entangled quantum states in long-wavelength modes in the universe result in modifications to the Friedmann Equation and a corresponding modification to inflationary dynamics. Previous work [1, 2] suggested that such effects could provide an explanation for well-known anomalies in the Cosmic Microwave Background (CMB), such as the lack of power on large scales and the ``cold spot'' seen by both the WMAP and Planck satellites. In this paper, we compute limits on these entanglement effects from the Planck CMB data combined with the BICEP/Keck polarization measurement, and find no evidence for observable modulations to the power spectrum from landscape entanglement, and no sourcing of observable CMB anomalies. The originally proposed model with an exponential potential is ruled out to high significance. Assuming a Starobinsky-type R2 inflation model, which is consistent with CMB constraints, data place a 2σ lower bound of b > 6.46 × 107 GeV on the Supersymmetry breaking scale associated with entanglement corrections.

  5. Tracing Evolution of Galactic Disks: Continuing the Legacy of HST / Keck with TMT, JWST and ALMA

    NASA Astrophysics Data System (ADS)

    Sheth, Kartik

    2014-07-01

    With HST and Keck we have been able to measure the detailed assembly of L* and brighter galaxy disks to z~0.85. We have shown evidence for downsizing in the formation and evolution of structures such as stellar bars. These signposts for disk maturity have allowed us to measure the precise rate of disk assembly over the last 7Gyr. Recent analysis of DEEP2 data also indicate that bars are absent in dynamically hot disks - however, we do not have solid measurements for stellar velocity dispersion in disks at high redshift. With the TMT we will be able to make such measurements for the first time. Combined with high resolution infrared observations from JWST we will be able to measure the stellar mass distribution and structures in disks to z~3. And with ALMA we are measuring the evolution of the molecular gas fraction and dust in disk galaxies. I will discuss the synergy of these new great observatories and describe how they will allow us to extend our study of disk assembly and evolution from the present day to the epoch of disk formation at z~3. I will also discuss how these facilities will allow us to push the boundaries of such studies to lower mass (sub-L*) galaxies.

  6. W. M. Keck Observatory primary mirror segment repair project: overview and status

    NASA Astrophysics Data System (ADS)

    Meeks, Robert L.; Doyle, Steve; Higginson, Jamie; Hudek, John S.; Irace, William; McBride, Dennis; Pollard, Mike; Tai, Kuochou; Von Boeckmann, Tod; Wold, Leslie; Wold, Truman

    2016-07-01

    The W. M. Keck Observatory Segment Repair Project is repairing stress-induced fractures near the support points in the primary mirror segments. The cracks are believed to result from deficiencies in the original design and implementation of the adhesive joints connecting the Invar support components to the ZERODUR mirror. Stresses caused by temperature cycling over 20 years of service drove cracks that developed at the glass-metal interfaces. Over the last few years the extent and cause of the cracks have been studied, and new supports have been designed. Repair of the damaged glass required development of specialized tools and procedures for: (1) transport of the segments; (2) pre-repair metrology to establish the initial condition; (3) removal of support hardware assemblies; (4) removal of the original supports; (5) grinding and re-surfacing the damaged glass areas; (6) etching to remove sub-surface damage; (7) bonding new supports; (8) re-installation of support assemblies; and (9) post-repair metrology. Repair of the first segment demonstrated the new tools and processes. On-sky measurements before and after repair verified compliance with the requirements. This paper summarizes the repair process, on-sky results, and transportation system, and also provides an update on the project status and schedule for repairing all 84 mirror segments. Strategies for maintaining quality and ensuring that repairs are done consistently are also presented.

  7. Single-wavelength coarse phasing in segmented telescopes.

    PubMed

    Simar, J F; Stockman, Y; Surdej, J

    2015-02-10

    Space observations of fainter and more distant astronomical objects constantly require telescope primary mirrors with larger sizes. The diameters of monolithic primary mirrors are restricted to 10 m because of manufacturing limitations. For space telescopes, the primary mirrors are limited to less than 5 m due to fairing capacity. Segmented primary mirrors thus constitute an alternative solution to deal with the steady increase of primary mirror size. The optical path difference between the individual segments must be close to 0 (a few nanometers) in order to be diffraction-limited. In this paper, we propose a new intersegment piston sensor based on the coherence measurement of a star image. This sensor is intended to be used in the co-phasing system of future segmented mirrors.

  8. Data Management at the Southern African Large Telescope

    NASA Astrophysics Data System (ADS)

    Crawford, Steve

    2015-12-01

    PySALT is the python/PyRAF-based data reduction and analysis pipeline for the Southern African Large Telescope (SALT), a modern 10m class telescope with a large user community consisting of 13 partner institutions. The suite of tools developed as part of PySALT include: (1) science quality reductions for the major operational modes of SALT include high-time resolution and spectroscopic reductions, (2) quick-look capabilities for the observers and real-time data delivery for the investigators, and (3) management of the data archive and regularly processing of SALT observations. In addition to presenting the overall framework, we also highlight some of the lessons learned since the start of SALT scientific observations in 2011.

  9. Large space telescope, phase A. Volume 3: Optical telescope assembly

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The development and characteristics of the optical telescope assembly for the Large Space Telescope are discussed. The systems considerations are based on mission-related parameters and optical equipment requirements. Information is included on: (1) structural design and analysis, (2) thermal design, (3) stabilization and control, (4) alignment, focus, and figure control, (5) electronic subsystem, and (6) scientific instrument design.

  10. Gamma-Ray Telescopes: 400 Years of Astronomical Telescopes

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Cannizzo, John K.

    2010-01-01

    The last half-century has seen dramatic developments in gamma-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as gamma-ray bursts, blazars, Galactic transients, and the Galactic distribution of Al-26.

  11. SIM.EM-K3 Key comparison of 10 mH inductance standards at 1 kHz

    NASA Astrophysics Data System (ADS)

    Moreno, J. A.; Côté, M.; Koffman, A.; Castro, B. I.; Vasconcellos, R. de Barros e.; Kyriazis, G.; Cazabat, M.; Izquierdo, D.; Faverio, C.; Slomovitz, D.

    2016-01-01

    A key comparison of 10 mH inductance standards at 1 kHz has been carried out with the participation of seven National Metrology Institutes of the Inter-American Metrology System, within the frame of the International Committee for Weights and Measures Mutual Recognition Arrangement (MRA), which was piloted by CENAM, Mexico. Three previously characterized commercial inductors, contained in individual enclosures with controlled temperature were used as traveling standards. This document presents the results and technical details of the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  12. Properties of nanocrystalline Fe75Si15M10 (M-Cr and Al) powders prepared by mechanical alloying.

    PubMed

    Kalita, M P C; Perumal, A; Srinivasan, A; Pandey, Brajesh; Verma, H C

    2008-08-01

    We report the structural and magnetic properties of the nanocrystalline Fe75Si15M10 (M-Al and Cr) powders prepared by mechanical alloying. The milling process produced a non-equilibrium solid solutions of bcc alpha-Fe(Si,Cr) and alpha-Fe(Si,Al). The average dislocation density increases and the average crystallite size decreases with increasing milling time. Magnetic property studies show that the coercivity of the sample increases and magnetization of the sample decreases with increasing milling time. The evolution of a non-equilibrium solid solution and the resulting magnetic properties of nanocrystalline powders are explained on the basis of Neel theory and modified random anisotropy model proposed by Shen et al.

  13. Identifying Meteor Streams Containing 10-m Bolides in Near-Earth Space and Determining their Temporal Evolution

    NASA Astrophysics Data System (ADS)

    Lai, H.; Russell, C. T.; Wei, H.; Delzanno, G.; Connors, M. G.

    2013-12-01

    The collision rate of small bodies orbiting the Sun increases with decreasing size. While small bodies in the 10-m class are difficult to detect from Earth, they are relatively easily detected by interplanetary spacecraft with magnetometers. A 10m body need be struck by a body only 20 cm across (traveling at 20 km/s) to be completely disrupted. The solar wind will sweep up the charged nano-scale dust as it flows through the debris forming a magnetic cloud. Because of the large size of the magnetic cloud only a small drop in the solar wind speed is needed to provide the momentum flux required to accelerate the cloud radially from the Sun. The cloud is carried outward and can be detected by any one of several interplanetary spacecraft. This procedure was first utilized on debris co-orbiting with the comet 2201 Oljato as monitored beginning in 1978 by the Pioneer Venus Orbiter and followed up by Venus Express that is still in operation. The meteoroid trail dissipated in just 30 years. We have used ACE, Wind and STEREO to identify a meteor stream co-orbiting with asteroid 138175 whose descending node is aligned with the Sun and the Earth on about April 17 each year. We have followed this trail from 1998 to the present and find that material extends to over 30° in front of the asteroid. It has been a steady producer of collisions over the last 15 years. The period of very close approach of this material to Earth may be over for a while but the material should be accessible by robotic or crewed missions as the orbit of 139175 has only a modest eccentricity and inclination to the ecliptic plane. Matching orbits with it should be similar in difficulty to a Venus flyby mission.

  14. Heart rate recovery after the 10-m incremental shuttle walking test in older adults with intellectual disabilities.

    PubMed

    Oppewal, Alyt; Hilgenkamp, Thessa I M; van Wijck, Ruud; Evenhuis, Heleen M

    2014-03-01

    Heart rate recovery (HRR) after exercise is an independent predictor for cardiovascular and all-cause mortality. To investigate the usefulness of HRR in cardiorespiratory exercise testing in older adults with intellectual disabilities (ID), the aims of this study were (a) to assess HRR in older adults with ID after the 10-m incremental shuttle walking test (ISWT) and (b) its association with personal characteristics (gender, age, distance walked on the ISWT, level of ID, genetic syndrome causing ID, autism, behavioral problems, and peak heart rate (HRpeak)). HRR was assessed after the 10-m incremental shuttle walking test in 300 older adults (>50 years) with borderline to profound ID. HRR was defined as the change from HRpeak during the ISWT to heart rate measured after 1, 2, 3, 4, and 5 min of passive recovery. The largest decrease in heart rate was in the first minute of recovery leveling off toward the fifth minute of recovery. An abnormal HHR (≤12 bpm) was seen in 36.1% of the participants with Down syndrome (DS) and in 30.7% of the participants with ID by other causes. After the fifth minute the heart rates of 69.4% of the participants with DS and of 61.4% of the participants with ID by other causes returned to resting levels. HRpeak and distance walked on the ISWT were positively related to all HRR measures. More severe ID was negatively related and having DS positively related to HRR after 3-5 min of recovery. The other characteristics were not significantly associated to HRR. HRR is a potentially useful outcome measure in cardiorespiratory fitness testing of older adults with ID with a direct, objective, and non-invasive measurement. Further research is needed to identify the relation between HRR and adverse health outcomes in this population.

  15. The Travelling Telescope

    NASA Astrophysics Data System (ADS)

    Owen, Daniel

    2015-08-01

    The telescope has been around for over 400 years, yet most people have never looked though one. We invite people outside under the stars to learn about those curious lights in the sky, and have a close encounter with the cosmos.Our main aim is to promote science, technology, engineering, and mathematics to the young minds by inspiring, empowering and engaging them using astronomy and astrophysics tools and concepts. We would like to see Africa compete with the rest of the world and we believe this can happen through having a scientifically literate society. We also work closely wit teachers, parents and the general public to further our objectives. We will present on our recently awarded project to work with schools in rural coastal Kenya, a very poor area of the country. We will also present on other work we continue to do with schools to make our project sustainable even after the OAD funding.

  16. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Astronomers using the Hubble Space Telescope (HST) have identified what may be the most luminous star known; a celestial mammoth that releases up to 10-million times the power of the Sun and is big enough to fill the diameter of Earth's orbit. The star unleashes as much energy in six seconds as our Sun does in one year. The image, taken by a UCLA-led team with the recently installed Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) aboard the HST, also reveals a bright nebula, created by extremely massive stellar eruptions. The UCLA astronomers estimate that the star, called the Pistol Star, (for the pistol shaped nebula surrounding it), is approximately 25,000 light-years from Earth, near the center of our Milky Way galaxy. The Pistol Star is not visible to the eye, but is located in the direction of the constellation Sagittarius, hidden behind the great dust clouds along the Milky Way

  17. Composite telescope technology

    NASA Astrophysics Data System (ADS)

    Chen, Peter C.; Rabin, Douglas

    2014-07-01

    We report the development of optical mirrors based on polymer matrix composite materials. Advantages of this technology are low cost and versatility. By using appropriate combinations of polymers and various metallic and nonmetallic particles and fibers, the properties of the materials can be tailored to suit a wide variety of applications. We report the fabrication and testing of flat and curved mirrors made with metal powders, multiple mirrors replicated with high degree of uniformity from the same mandrels, cryogenic testing, mirrors made of ferromagnetic materials that can be actively or adaptively controlled by non-contact actuation, optics with very smooth surfaces made by replication, and by spincasting. We discuss development of a new generation of ultra-compact, low power active optics and 3D printing of athermal telescopes.

  18. Actuated Hybrid Mirror Telescope

    NASA Technical Reports Server (NTRS)

    Hickey, Gregory; Redding, David; Lowman, Andrew; Cohen, David; Ohara, Catherine

    2005-01-01

    The figure depicts the planned Actuated Hybrid Mirror Telescope (AHMT), which is intended to demonstrate a new approach to the design and construction of wide-aperture spaceborne telescopes for astronomy and Earth science. This technology is also appropriate for Earth-based telescopes. The new approach can be broadly summarized as using advanced lightweight mirrors that can be manufactured rapidly at relatively low cost. More specifically, it is planned to use precise replicated metallic nanolaminate mirrors to obtain the required high-quality optical finishes. Lightweight, dimensionally stable silicon carbide (SiC) structures will support the nanolaminate mirrors in the required surface figures. To enable diffraction- limited telescope performance, errors in surface figures will be corrected by use of mirror-shape-control actuators that will be energized, as needed, by a wave-front-sensing and control system. The concepts of nanolaminate materials and mirrors made from nanolaminate materials were discussed in several previous NASA Tech Briefs articles. Nanolaminates constitute a relatively new class of materials that can approach theoretical limits of stiffness and strength. Nanolaminate mirrors are synthesized by magnetron sputter deposition of metallic alloys and/or compounds on optically precise master surfaces to obtain optical-quality reflector surfaces backed by thin shell structures. As an integral part of the deposition process, a layer of gold that will constitute the reflective surface layer is deposited first, eliminating the need for a subsequent and separate reflective-coating process. The crystallographic textures of the nanolaminate will be controlled to optimize the performance of the mirror. The entire deposition process for making a nanolaminate mirror takes less than 100 hours, regardless of the mirror diameter. Each nanolaminate mirror will be bonded to its lightweight SiC supporting structure. The lightweight nanolaminate mirrors and Si

  19. The Metagenomic Telescope

    PubMed Central

    Szalkai, Balázs; Scheer, Ildikó; Nagy, Kinga; Vértessy, Beáta G.; Grolmusz, Vince

    2014-01-01

    Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well–known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair); next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well–researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis); and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms. PMID:25054802

  20. The metagenomic telescope.

    PubMed

    Szalkai, Balázs; Scheer, Ildikó; Nagy, Kinga; Vértessy, Beáta G; Grolmusz, Vince

    2014-01-01

    Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well-known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair); next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well-researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis); and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms.

  1. A Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

    NASA Astrophysics Data System (ADS)

    Conti, Alberto; Arenberg, Jonathan; Baldauf, Brian

    2017-01-01

    The “Search for Life” (direct imaging of earth-like planets) will require extremely stable telescopes with apertures in the 10 m to 20 m range. Such apertures are larger than what can be delivered to space using current or planned future launch vehicles. Building and assembling large telescopes in space is therefore likely to require not only multiple launches but importantly assembly in spce. As a result, space-based telescopes with large apertures will require major changes to our conventional telescope design and architecture.Here we report on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST) to demonstrates the on-orbit robotic and/or astronaut assembly of an optical telescope in space. MODEST is a proposed International Space Station (ISS demonstration that will make use of the standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets.MODEST will provides significant risk reduction for the next generation of space observatories, and demonstrates the technology needed to assemble a six-mirror phased telescope. Key modest features include the use of an active primary optical surface with wavefront feedback control to allow on-orbit optimization, and the precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer (CFRP) that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal conductivity, and low thermal expansion. Mirrors built from these materials can be rapidly replicated in a highly cost effective manner, making them an excellent candidate for a low cost, high performance Optical Telescope Assembly paving the way for enabling affordable solutions for the next generation of large aperture space-based telescope.MODEST post-assembly value includes space, ground, and

  2. Kashima 34-m Radio Telescope

    NASA Technical Reports Server (NTRS)

    Sekido, Mamoru; Kawai, Eiji

    2013-01-01

    The Kashima 34-m radio telescope has been continuously operated and maintained by the National Institute of Information and Communications Technology (NICT) as a facility of the Kashima Space Technology Center (KSTC) in Japan. This brief report summarizes the status of this telescope, the staff, and activities during 2012.

  3. Astrometry with Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Benedict, G.; Murdin, P.

    2000-11-01

    In 1990 NASA launched the HUBBLE SPACE TELESCOPE. In addition to cameras and spectrographs usable from the far ultraviolet to the near-infrared, the observatory contains three white-light INTERFEROMETERS. As part of engineering and science support their primary task was telescope guiding; to position and hold science targets within the science instrument apertures with tolerances approaching 0.1'...

  4. Telescopes, Mounts and Control Systems

    NASA Astrophysics Data System (ADS)

    Mobberley, M.; Murdin, P.

    2003-04-01

    The amateur astronomer used to have a relatively basic choice of equipment: a refractor (see REFRACTING TELESCOPES), or a Newtonian reflector (see REFLECTING TELESCOPES); there were few other options. The refractor has always been the stereotype astronomer's instrument: a spy glass, with a lens at one end and an eyepiece at the other. However, in practice, the reflector has always been better aper...

  5. High Resolution Near-IR Spectroscopy of Protostars With Large Telescopes

    NASA Technical Reports Server (NTRS)

    Greene, Tom; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    It is now possible to measure absorption spectra of Class I protostars using D greater than or = 8m telescopes equipped with sensitive cryogenic IR spectrographs. Our latest high-resolution (R approx. 20,000) Keck data reveal that Class I protostars are indeed low-mass stars with dwarf-like features. However, they differ from T Tauri stars in that Class I protostars have much higher IR veilings (tau(sub k) greater than or = 1 - 3+) and they are rotating quickly, v sin i greater than 20 km/s. Interestingly, the vast majority of protostellar absorption spectra show stellar - not disk - absorption features. A preliminary H-R diagram suggests that protostellar photospheres may have different physical structures than T Tauri stars, perhaps due to their higher accretion rates.

  6. Wind buffeting of large telescopes.

    PubMed

    MacMynowski, Douglas G; Andersen, Torben

    2010-02-01

    Unsteady wind loads due to turbulence within the telescope enclosure are one of the largest dynamic disturbances for ground-based optical telescopes. The desire to minimize the response to the wind influences the design of the telescope enclosure, structure, and control systems. There is now significant experience in detailed integrated modeling to predict image jitter due to wind. Based on this experience, a relatively simple model is proposed that is verified (from a more detailed model) to capture the relevant physics. In addition to illustrating the important elements of the telescope design that influence wind response, this model is used to understand the sensitivity of telescope image jitter to a wide range of design parameters.

  7. Seismic Imager Space Telescope

    NASA Technical Reports Server (NTRS)

    Sidick, Erkin; Coste, Keith; Cunningham, J.; Sievers,Michael W.; Agnes, Gregory S.; Polanco, Otto R.; Green, Joseph J.; Cameron, Bruce A.; Redding, David C.; Avouac, Jean Philippe; Ampuero, Jean Paul; Leprince, Sebastien; Michel, Remi

    2012-01-01

    A concept has been developed for a geostationary seismic imager (GSI), a space telescope in geostationary orbit above the Pacific coast of the Americas that would provide movies of many large earthquakes occurring in the area from Southern Chile to Southern Alaska. The GSI movies would cover a field of view as long as 300 km, at a spatial resolution of 3 to 15 m and a temporal resolution of 1 to 2 Hz, which is sufficient for accurate measurement of surface displacements and photometric changes induced by seismic waves. Computer processing of the movie images would exploit these dynamic changes to accurately measure the rapidly evolving surface waves and surface ruptures as they happen. These measurements would provide key information to advance the understanding of the mechanisms governing earthquake ruptures, and the propagation and arrest of damaging seismic waves. GSI operational strategy is to react to earthquakes detected by ground seismometers, slewing the satellite to point at the epicenters of earthquakes above a certain magnitude. Some of these earthquakes will be foreshocks of larger earthquakes; these will be observed, as the spacecraft would have been pointed in the right direction. This strategy was tested against the historical record for the Pacific coast of the Americas, from 1973 until the present. Based on the seismicity recorded during this time period, a GSI mission with a lifetime of 10 years could have been in position to observe at least 13 (22 on average) earthquakes of magnitude larger than 6, and at least one (2 on average) earthquake of magnitude larger than 7. A GSI would provide data unprecedented in its extent and temporal and spatial resolution. It would provide this data for some of the world's most seismically active regions, and do so better and at a lower cost than could be done with ground-based instrumentation. A GSI would revolutionize the understanding of earthquake dynamics, perhaps leading ultimately to effective warning

  8. Modeling Neptune’s Upper Troposphere and Stratosphere from Keck Spectra

    NASA Astrophysics Data System (ADS)

    Luszcz-Cook, Statia H.; de Kleer, Katherine; de Pater, Imke; Ádámkovics, Máté; Hammel, Heidi B.

    2014-11-01

    More than three decades after Voyager 2 left Neptune, the structure and variability of aerosols in Neptune’s upper troposphere and stratosphere remain enigmatic. Bands of discrete, bright clouds dominate the appearance of Neptune in the near infrared, but they are not the only aerosols that must be present in the upper atmosphere. Many studies indicate a global cloud layer is present at 2-4 bars. Thermochemical equilibrium models argue for a series of thick global cloud decks in Neptune’s troposphere; hence the 2-4 bar cloud layer was originally presupposed to be spatially uniform and optically thick, and was tentatively identified as hydrogen sulfide ice. However, other results suggest this cloud may be optically thin (Sromovsky et al. 2001), spatially variable (Irwin et al. 2011) or may not exist at all, with the tropospheric opacity instead arising from vertically extended haze (Karkoschka and Tomasko 2011). At higher altitudes, some — but not all — models include an optically thin methane haze at 1-2 bar, and one or more optically thin stratospheric haze layers, formed by the settling of photochemically-produced hydrocarbons.Derivation of Neptune’s aerosol structure from observations depends on one’s assumptions for the vertical temperature and methane mixing ratio profiles, which are uncertain. The picture is further complicated by evidence that these atmospheric properties likely vary with latitude (e.g., Conrath et al. 1998, Karkoschka and Tomasko 2011). We describe our recent efforts to constrain the aerosol structure of Neptune using data from the Keck OSIRIS integral field spectrograph and a Markov chain Monte Carlo algorithm, focusing on regions free of discrete bright clouds. We will discuss the variability of this background aerosol structure with latitude, considering the effects of compositional and thermal variations. We will address our ability to place constraints on the composition and temperature as well as the properties of the

  9. Exozodiacal Dust Levels for Nearby Main-sequence Stars: A Survey with the Keck Interferometer Nuller

    NASA Astrophysics Data System (ADS)

    Millan-Gabet, R.; Serabyn, E.; Mennesson, B.; Traub, W. A.; Barry, R. K.; Danchi, W. C.; Kuchner, M.; Stark, C. C.; Ragland, S.; Hrynevych, M.; Woillez, J.; Stapelfeldt, K.; Bryden, G.; Colavita, M. M.; Booth, A. J.

    2011-06-01

    The Keck Interferometer Nuller (KIN) was used to survey 25 nearby main-sequence stars in the mid-infrared, in order to assess the prevalence of warm circumstellar (exozodiacal) dust around nearby solar-type stars. The KIN measures circumstellar emission by spatially blocking the star but transmitting the circumstellar flux in a region typically 0.1-4 AU from the star. We find one significant detection (η Crv), two marginal detections (γ Oph and α Aql), and 22 clear non-detections. Using a model of our own solar system's zodiacal cloud, scaled to the luminosity of each target star, we estimate the equivalent number of target zodis needed to match our observations. Our three zodi detections are η Crv (1250 ± 260), γ Oph (200 ± 80), and α Aql (600 ± 200), where the uncertainties are 1σ. The 22 non-detected targets have an ensemble weighted average consistent with zero, with an average individual uncertainty of 160 zodis (1σ). These measurements represent the best limits to date on exozodi levels for a sample of nearby main-sequence stars. A statistical analysis of the population of 23 stars not previously known to contain circumstellar dust (excluding η Crv and γ Oph) suggests that, if the measurement errors are uncorrelated (for which we provide evidence) and if these 23 stars are representative of a single class with respect to the level of exozodi brightness, the mean exozodi level for the class is <150 zodis (3σ upper limit, corresponding to 99% confidence under the additional assumption that the measurement errors are Gaussian). We also demonstrate that this conclusion is largely independent of the shape and mean level of the (unknown) true underlying exozodi distribution.

  10. Measuring temperature and ammonia hydrate ice on Charon in 2015 from Keck/OSIRIS spectra

    NASA Astrophysics Data System (ADS)

    Holler, B. J.; Young, L. A.; Buie, M. W.; Grundy, W. M.; Lyke, J. E.; Young, E. F.; Roe, H. G.

    2017-03-01

    In this work we investigated the longitudinal (zonal) variability of H2O and ammonia (NH3) hydrate ices on the surface of Charon through analysis of the 1.65 μm and 2.21 μmabsorption features, respectively. Near-infrared spectra presented here were obtained between 2015-07-14 and 2015-08-30 UT with the OSIRIS integral field spectrograph on Keck I. Spectra centered on six different sub-observer longitudes were obtained through the Hbb (1.473-1.803 μm) and Kbb (1.965-2.381 μm) filters. Gaussian functions were fit to the aforementioned bands to obtain information on band center, band depth, full width at half maximum, and band area. The shift in the band center of the temperature-dependent 1.65 μm feature was used to calculate the H2O ice temperature. The mean temperature of the ice on the observable portion of Charon's surface is 45 ± 14 K and we report no statistically significant variations in temperature across the surface. We hypothesize that the crystalline and amorphous phases of water ice reached equilibrium over 3.5 Gyr ago, with thermal recrystallization balancing the effects of irradiation amorphization. We do not believe that cryovolcanism is necessary to explain the presence of crystalline water ice on the surface of Charon. Absorption from ammonia species is detected between 12° and 290°, in agreement with results from New Horizons. Ongoing diffusion of ammonia through the rocky mantle and upper layer of water ice is one possible mechanism for maintaining its presence in Charon's surface ice. Reduced Charon spectra corrected for telluric and solar absorption are available as supplementary online material.

  11. Keck/NIRC2 Imaging of the Warped, Asymmetric Debris Disk Around HD 32297

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Rodigas, Timothy J.; Debes, John; Plavchan, Peter; Kuchner, Marc; Jang, Condell, Hannah; Wilner, David; Andrews, Sean; Dahm, Scott; Robitaille,Thomas

    2012-01-01

    We present Keck/NIRC2 K(sub s) band high-contrast coronagraphic imaging of the luminous debris disk around the nearby, young A star HD 32297 resolved at a projected separation of r = 0.3 - 2.5" (approx equals 35 - 280 AU). The disk is highly warped to the north and exhibits a complex, "wavy" surface brightness profile interior to r approx equals 110 AU, where the peaks/plateaus in the profiles are shifted between the NE and SW disk lobes. The SW side of the disk is 50 - 100% brighter at r = 35 - 80 AU, and the location of its peak brightness roughly coincides with the disk's mm emission peak. Spectral energy distribution modeling suggests that HD 32297 has at least two dust populations that may originate from two separate belts likely at different locations, possibly at distances coinciding with the surface brightness peaks. A disk model fur a single dust belt including a phase function with two components and a 5 - 10 AU pericenter offset explains the disk's warped structure and reproduces some of the surface brightness profile's shape (e.g. the overall "wavy" profile, the SB peak/plateau shifts) but more poorly reproduces the disk's brightness asymmetry and the profile at wider separations (r > 110 AU). Although there may be a1ternate explanations, agreement between the SW disk brightness peak and disk's peak rom emission is consistent with an overdensity of very small, sub-blowout-sized dust and large, 0.1 - 1 mm-sized grains at approx equal 45 AU tracing the same parent population of planetesimals. New near-IR and submm observations may be able to clarify whether even more complex grain scattering properties or dynamical sculpting by an unseen planet are required to explain HD 32297's disk structure.

  12. Back to the future: virtualization of the computing environment at the W. M. Keck Observatory

    NASA Astrophysics Data System (ADS)

    McCann, Kevin L.; Birch, Denny A.; Holt, Jennifer M.; Randolph, William B.; Ward, Josephine A.

    2014-07-01

    Over its two decades of science operations, the W.M. Keck Observatory computing environment has evolved to contain a distributed hybrid mix of hundreds of servers, desktops and laptops of multiple different hardware platforms, O/S versions and vintages. Supporting the growing computing capabilities to meet the observatory's diverse, evolving computing demands within fixed budget constraints, presents many challenges. This paper describes the significant role that virtualization is playing in addressing these challenges while improving the level and quality of service as well as realizing significant savings across many cost areas. Starting in December 2012, the observatory embarked on an ambitious plan to incrementally test and deploy a migration to virtualized platforms to address a broad range of specific opportunities. Implementation to date has been surprisingly glitch free, progressing well and yielding tangible benefits much faster than many expected. We describe here the general approach, starting with the initial identification of some low hanging fruit which also provided opportunity to gain experience and build confidence among both the implementation team and the user community. We describe the range of challenges, opportunities and cost savings potential. Very significant among these was the substantial power savings which resulted in strong broad support for moving forward. We go on to describe the phasing plan, the evolving scalable architecture, some of the specific technical choices, as well as some of the individual technical issues encountered along the way. The phased implementation spans Windows and Unix servers for scientific, engineering and business operations, virtualized desktops for typical office users as well as more the more demanding graphics intensive CAD users. Other areas discussed in this paper include staff training, load balancing, redundancy, scalability, remote access, disaster readiness and recovery.

  13. ZFIRE: A KECK/MOSFIRE Spectroscopic Survey of Galaxies in Rich Environments at z ˜ 2

    NASA Astrophysics Data System (ADS)

    Nanayakkara, Themiya; Glazebrook, Karl; Kacprzak, Glenn G.; Yuan, Tiantian; Tran, Kim-Vy; Spitler, Lee; Kewley, Lisa; Straatman, Caroline; Cowley, Michael; Fisher, David; Labbe, Ivo; Tomczak, Adam; Allen, Rebecca; Alcorn, Leo

    2016-09-01

    We present an overview and the first data release of ZFIRE, a spectroscopic redshift survey of star-forming galaxies that utilizes the MOSFIRE instrument on Keck-I to study galaxy properties in rich environments at 1.5 < z < 2.5. ZFIRE measures accurate spectroscopic redshifts and basic galaxy properties derived from multiple emission lines. The galaxies are selected from a stellar mass limited sample based on deep near infrared imaging ({K}{AB}\\lt 25) and precise photometric redshifts from the ZFOURGE and UKIDSS surveys as well as grism redshifts from 3DHST. Between 2013 and 2015, ZFIRE has observed the COSMOS and UDS legacy fields over 13 nights and has obtained 211 galaxy redshifts over 1.57 < z < 2.66 from a combination of nebular emission lines (such as Hα, [N ii], Hβ, [O ii], [O iii], and [S ii]) observed at 1-2 μm. Based on our medium-band near infrared photometry, we are able to spectrophotometrically flux calibrate our spectra to ˜10% accuracy. ZFIRE reaches 5σ emission line flux limits of ˜3 × 10-18 erg s-1 cm-2 with a resolving power of R = 3500 and reaches masses down to ˜109 M ⊙. We confirm that the primary input survey, ZFOURGE, has produced photometric redshifts for star-forming galaxies (including highly attenuated ones) accurate to {{Δ }}z/(1+{z}{spec})=0.015 with 0.7% outliers. We measure a slight redshift bias of <0.001, and we note that the redshift bias tends to be larger at higher masses. We also examine the role of redshift on the derivation of rest-frame colors and stellar population parameters from SED fitting techniques. The ZFIRE survey extends spectroscopically confirmed z ˜ 2 samples across a richer range of environments, here we make available the first public release of the data for use by the community.7

  14. The Keck OSIRIS Nearby AGN Survey: Tracing Inflow within the Central 200 pc of Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    Hicks, Erin K. S.; Müller-Sánchez, Francisco; Malkan, Matthew A.; Yu, Po-Chieh

    2016-08-01

    In an effort to identify the fundamental processes driving feeding and feedback in AGN we turn to local Seyfert galaxies and rely on a multi-wavelength approach. With the integral field unit OSIRIS and adaptive optics we characterize the nuclear stars and gas down to scales of 5-30 parsecs in a sample of 40 Seyfert galaxies with the Keck OSIRIS Nearby AGN (KONA) survey. The complex gas kinematics in these near-IR data are interpreted using an integrative approach through comparison with data available at a range of wavelengths. We present first results from the survey with a focus on work aimed at constraining the mechanism(s) driving inflow of material within the central 200 pc. Particularly useful in the identification of inflow mechanisms (e.g. nuclear spiral, external accretion) is spatial correlation of the molecular gas distribution and kinematics with dust features revealed in HST imaging (optical and near-IR). Also informative is comparison with X-ray emission to identify locations likely influenced by interactions with outflows. The stellar kinematics in the sample galaxies (traced by CO bandheads at 2.3 microns) indicate a stellar population within the central few 100 parsecs in circular rotation, and in the majority of the galaxies the molecular gas (traced by H2 emission at 2.1218 microns) is found to have a rotating component co-spatial with the stellar disk. A significant fraction of the galaxies also exhibit kinematic signatures of inflow superimposed on this disk rotation, with inflow driven by secular and non-secular processes identified. We explore statistical trends of the nuclear stellar and molecular gas properties, including primary fueling mechanism, with Seyfert type, AGN luminosity, and host environment with the goal of disentangling which properties are fundamental to the nature of the AGN.

  15. KECK/NIRC2 IMAGING OF THE WARPED, ASYMMETRIC DEBRIS DISK AROUND HD 32297

    SciTech Connect

    Currie, Thayne; Kuchner, Marc; Rodigas, Timothy J.; Debes, John; Plavchan, Peter; Jang-Condell, Hannah; Wilner, David; Andrews, Sean; Kraus, Adam; Dahm, Scott; Robitaille, Thomas

    2012-09-20

    We present Keck/NIRC2 K{sub s} -band high-contrast coronagraphic imaging of the luminous debris disk around the nearby, young A star HD 32297 resolved at a projected separation of r = 0.''3-2.''5 ( Almost-Equal-To 35-280 AU). The disk is highly warped to the north and exhibits a complex, 'wavy' surface brightness (SB) profile interior to r Almost-Equal-To 110 AU, where the peaks/plateaus in the profiles are shifted between the NE and SW disk lobes. The SW side of the disk is 50%-100% brighter at r = 35-80 AU, and the location of its peak brightness roughly coincides with the disk's millimeter (mm) emission peak. Spectral energy distribution modeling suggests that HD 32297 has at least two dust populations that may originate from two separate belts, likely at different locations, possibly at distances coinciding with the SB peaks. A disk model for a single dust belt including a phase function with two components and a 5-10 AU pericenter offset explains the disk's warped structure and reproduces some of the SB profile's shape (e.g., the overall 'wavy' profile, the SB peak/plateau shifts) but more poorly reproduces the disk's brightness asymmetry and the profile at wider separations (r > 110 AU). Although there may be alternate explanations, agreement between the SW disk brightness peak and disk's peak mm emission is consistent with an overdensity of very small, sub-blowout-sized dust and large, 0.1-1 mm sized grains at Almost-Equal-To 45 AU tracing the same parent population of planetesimals. New near-IR and submillimeter observations may be able to clarify whether even more complex grain scattering properties or dynamical sculpting by an unseen planet are required to explain HD 32297's disk structure.

  16. Keck/NIRC2 Imaging of the Warped, Asymmetric Debris Disk Around HD 32297

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Rodigas, Timothy J.; Debes, John; Plavchan, Peter; Kuchner, Marc; Jang-Condell, Hannah; Wilner, David; Andrews, Sean; Kraus, Adam; Dahm, Scott; Robitaille, Thomas

    2012-01-01

    We present Keck/NIRC2 Ks band high-contrast coronagraphic imaging of the luminous debris disk around the nearby, young A star HD 32297 resolved at a projected separation of r = 0.3-2.5 arcse (approx 35-280 AU). The disk is highly warped to the north and exhibits a complex, "wavy" surface brightness profile interior to r approx 110 AU, where the peaks/plateaus in the profiles are shifted between the NE and SW disk lobes. The SW side of the disk is 50 - 100% brighter at r = 35 - 80 AU, and the location of its peak brightness roughly coincides with the disk's mm emission peak. Spectral energy distribution modeling suggests that HD 32297 has at least two dust populations that may originate from two separate belts likely at different locations, possibly at distances coinciding with the surface brightness peaks. A disk model for a single dust belt including a phase function with two components and a 5-10 AU pericenter offset explains the disk's warped structure and reproduces some of the surface brightness profile's shape (e.g. the overall "wavy" profile, the SB peak/plateau shifts) but more poorly reproduces the disk's brightness asymmetry. Although there may be alternate explanations, agreement between the SW disk brightness peak and disk's peak mm emission is consistent with an overdensity of very small, sub-blowout-sized dust and large, 0.1-1 mm-sized grains at approx 45 AU tracing the same parent population of planetesimals. New near-IR and submm observations may be able to clarify whether even more complex grain scattering properties or dynamical sculpting by an unseen planet are required to explain HD 32297's disk structure.

  17. A Ten-Meter Ground-Station Telescope for Deep-Space Optical Communications: A Preliminary Design

    NASA Technical Reports Server (NTRS)

    Britcliffe, M.; Hoppe, D.; Roberts, W.; Page, N.

    2001-01-01

    This article describes a telescope design for a 10-m optical ground station for deep-space communications. The design for a direct-detection optical communications telescope differs dramatically from a telescope for imaging applications. In general, the requirements for optical manufacturing and tracking performance are much less stringent for direct detection of optical signals. The technical challenge is providing a design that will operate in the daytime/nighttime conditions required for a Deep Space Network tracking application. The design presented addresses these requirements. The design will provide higher performance at lower cost than existing designs.

  18. MeV electron acceleration at 1kHz with <10 mJ laser pulses

    NASA Astrophysics Data System (ADS)

    Salehi, Fatholah; Goers, Andy; Hine, George; Feder, Linus; Kuk, Donghoon; Kim, Ki-Yong; Milchberg, Howard

    2016-10-01

    We demonstrate laser driven acceleration of electrons at 1 kHz repetition rate with pC charge above 1MeV per shot using < 10 mJ pulse energies focused on a near-critical density He or H2 gas jet. Using the H2 gas jet, electron acceleration to 0.5 MeV in 10 fC bunches was observed with laser pulse energy as low as 1.3mJ . Using a near-critical density gas jet sets the critical power required for relativistic self-focusing low enough for mJ scale laser pulses to self- focus and drive strong wakefields. Experiments and particle-in-cell simulations show that optimal drive pulse duration and chirp for maximum electron bunch charge and energy depends on the target gas species. High repetition rate, high charge, and short duration electron bunches driven by very modest pulse energies constitutes an ideal portable electron source for applications such as ultrafast electron diffraction experiments and high rep. rate γ-ray production. This work is supported by the US Department of Energy, the National Science Foundation, and the Air Force Office of Scientific Research.

  19. A 10 mK scanning tunneling microscope operating in ultra high vacuum and high magnetic fields.

    PubMed

    Assig, Maximilian; Etzkorn, Markus; Enders, Axel; Stiepany, Wolfgang; Ast, Christian R; Kern, Klaus

    2013-03-01

    We present design and performance of a scanning tunneling microscope (STM) that operates at temperatures down to 10 mK providing ultimate energy resolution on the atomic scale. The STM is attached to a dilution refrigerator with direct access to an ultra high vacuum chamber allowing in situ sample preparation. High magnetic fields of up to 14 T perpendicular and up to 0.5 T parallel to the sample surface can be applied. Temperature sensors mounted directly at the tip and sample position verified the base temperature within a small error margin. Using a superconducting Al tip and a metallic Cu(111) sample, we determined an effective temperature of 38 ± 1 mK from the thermal broadening observed in the tunneling spectra. This results in an upper limit for the energy resolution of ΔE = 3.5 kBT = 11.4 ± 0.3 μeV. The stability between tip and sample is 4 pm at a temperature of 15 mK as demonstrated by topography measurements on a Cu(111) surface.

  20. High-cycle fatigue of 10M Ni-Mn-Ga magnetic shape memory alloy in reversed mechanical loading

    NASA Astrophysics Data System (ADS)

    Aaltio, I.; Soroka, A.; Ge, Y.; Söderberg, O.; Hannula, S.-P.

    2010-07-01

    Application of Ni-Mn-Ga magnetic shape memory alloys in magnetic-field-induced actuation relies on their performance in long-term high-cycle fatigue. In this paper the performance and changes in the microstructure of a Ni-Mn-Ga 10M martensite single crystal material are reported in a long-term mechanically induced shape change cycling. The longest test was run for 2 × 109 cycles at a frequency of 250 Hz and a strain amplitude of ± 1%. After the test a clear increase of the dynamic stiffness of the material was detected. Three specimens out of ten were cycled until fracture occurred and their fracture mechanism was studied. It was observed that the macroscopic crack growth took place roughly at a 45° angle with respect to the loading direction that was along the lang100rang crystallographic direction of the sample. The macroscopic fracture plane seemed to correspond roughly to the {111} crystal planes. On a microscopic scale the fracture propagated in a step-like manner at least partly along crystallographic planes. The steps at the fracture plane correspond to the {101} twin planes, with the height of steps along the lang101rang direction. The final fracture of the samples occurred in a brittle manner after the critical stress was exceeded.

  1. SOFIA: Flying the Telescope

    NASA Technical Reports Server (NTRS)

    Asher, Troy; Cumming, Steve

    2012-01-01

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is an international cooperative development and operations program between the United States National Aeronautics and Space Administration (NASA) and the German Space Agency, DLR (Deutsches Zentrum fuer Luft-und Raumfahrt). SOFIA is a 2.5 meter, optical/infrared/sub-millimeter telescope mounted in a Boeing model 747SP-21 aircraft and will be used for many basic astronomical observations performed at stratospheric altitudes. It will accommodate installation of different focal plane instruments with in-flight accessibility provided by investigators selected from the international science community. The Facility operational lifetime is planned to be greater than 20 years. This presentation will present the results of developmental testing of SOFIA, including analysis, envelope expansion and the first operational mission. It will describe a brief history of open cavities in flight, how NASA designed and tested SOFIAs cavity, as well as flight test results. It will focus on how the test team achieved key milestones by systematically and efficiently reducing the number of test points to only those absolutely necessary to achieve mission requirements, thereby meeting all requirements and saving the potential loss of program funding. Finally, it will showcase examples of the observatory in action and the first operational mission of the observatory, illustrating the usefulness of the system to the international scientific community. Lessons learned on how to whittle a mountain of test points into a manageable sum will be presented at the conclusion.

  2. Astronomy with Small Telescopes

    NASA Astrophysics Data System (ADS)

    Paczynski, Bohdan

    2006-06-01

    While there are more than a dozen telescopes larger than 10 meters there is plenty of interesting astronomy which can be done with much smaller instruments. Notice that the existing SDSS, and the future PanSTARRS and LSST saturate at 15 mag. An example of interesting science is provided with ASAS (All Sky Automated Survey) which used aperture of 7 cm to discover over 50,000 variable stars brighter than 14 mag, covering almost 3/4 of the sky. Most of these are new discoveries.ASAS like instruments are most likely more efficient in a search for afterglows following gamma-ray bursts (GRB) than CFHT and its Megacam. In fact it should be possible to detect the afterglows without a GRB trigger by imaging all visible sky every 15 minutes down to 16 mag using a number of ASAS-like instruments.Another example of small instruments being essential, is their ability to detect 'killer asteroids' prior to their impact. It will take a number of small instruments, somewhat more powerful than ASAS, to detect boulders as small as 10 - 20 meters at a distance of several days prior to their impact. This will provide time to evacuate a region in case of Tunguska-like event, or to provide news of a spectacular but harmless event in case of a more modest impact.

  3. POST: Polar Stratospheric Telescope

    NASA Astrophysics Data System (ADS)

    Bely, Pierre Y.; Ford, Holland C.; Burg, Richard; Petro, Larry; White, Rick; Bally, John

    1995-10-01

    The tropopause, typically at 16 to 18 km altitude at the lower latitudes, dips to 8 km in the polar regions. This makes the cold, dry and nonturbulent lower stratosphere accessible to tethered aerostats. Tethered aerostats can fly as high as 12 km and are extremely reliable, lasting for many years. In contrast to free-flying balloons, they can stay on station for weeks at a time, and payloads can be safely recovered for maintenance and adjustment and relaunched in a matter of hours. We propose to use such a platform, located first in the Arctic (near Fairbanks, Alaska) and, potentially, later in the Antarctic, to operate a new technology 6-meter, diluted aperture telescope with diffraction-limited performance in the near infrared. Thanks to the low ambient temperature (220 K), thermal emission from the optics is of the same order as that of the zodiacal light in the 2 to 3 micron band. Since this wavelength interval is the darkest part of the zodiacal light spectrum from optical wavelengths to 100 microns, the combination of high resolution images and a very dark sky make it the spectral region of choice for observing the redshifted light from galaxies and clusters of galaxies at moderate to high redshifts.

  4. Operating a heterogeneous telescope network

    NASA Astrophysics Data System (ADS)

    Allan, Alasdair; Bischoff, Karsten; Burgdorf, Martin; Cavanagh, Brad; Christian, Damien; Clay, Neil; Dickens, Rob; Economou, Frossie; Fadavi, Mehri; Frazer, Stephen; Granzer, Thomas; Grosvenor, Sandy; Hessman, Frederic V.; Jenness, Tim; Koratkar, Anuradha; Lehner, Matthew; Mottram, Chris; Naylor, Tim; Saunders, Eric S.; Solomos, Nikolaos; Steele, Iain A.; Tuparev, Georg; Vestrand, W. Thomas; White, Robert R.; Yost, Sarah

    2006-06-01

    In the last few years the ubiquitous availability of high bandwidth networks has changed the way both robotic and non-robotic telescopes operate, with single isolated telescopes being integrated into expanding "smart" telescope networks that can span continents and respond to transient events in seconds. The Heterogeneous Telescope Networks (HTN)* Consortium represents a number of major research groups in the field of robotic telescopes, and together we are proposing a standards based approach to providing interoperability between the existing proprietary telescope networks. We further propose standards for interoperability, and integration with, the emerging Virtual Observatory. We present the results of the first interoperability meeting held last year and discuss the protocol and transport standards agreed at the meeting, which deals with the complex issue of how to optimally schedule observations on geographically distributed resources. We discuss a free market approach to this scheduling problem, which must initially be based on ad-hoc agreements between the participants in the network, but which may eventually expand into a electronic market for the exchange of telescope time.

  5. Space Telescope Systems Description Handbook

    NASA Technical Reports Server (NTRS)

    Carter, R. E.

    1985-01-01

    The objective of the Space Telescope Project is to orbit a high quality optical 2.4-meter telescope system by the Space Shuttle for use by the astronomical community in conjunction with NASA. The scientific objectives of the Space Telescope are to determine the constitution, physical characteristics, and dynamics of celestial bodies; the nature of processes which occur in the extreme physical conditions existing in stellar objects; the history and evolution of the universe; and whether the laws of nature are universal in the space-time continuum. Like ground-based telescopes, the Space Telescope was designed as a general-purpose instrument, capable of utilizing a wide variety of scientific instruments at its focal plane. This multi-purpose characteristic will allow the Space Telescope to be effectively used as a national facility, capable of supporting the astronomical needs for an international user community and hence making contributions to man's needs. By using the Space Shuttle to provide scientific instrument upgrading and subsystems maintenance, the useful and effective operational lifetime of the Space Telescope will be extended to a decade or more.

  6. Geodetic Observatory Wettzell - 20-m Radio Telescope and Twin Telescope

    NASA Technical Reports Server (NTRS)

    Neidhardt, Alexander; Kronschnabl, Gerhard; Schatz, Raimund

    2013-01-01

    In the year 2012, the 20-m radio telescope at the Geodetic Observatory Wettzell, Germany again contributed very successfully to the International VLBI Service for Geodesy and Astrometry observing program. Technical changes, developments, improvements, and upgrades were made to increase the reliability of the entire VLBI observing system. In parallel, the new Twin radio telescope Wettzell (TTW) got the first feedhorn, while the construction of the HF-receiving and the controlling system was continued.

  7. Lightweighted ZERODUR for telescopes

    NASA Astrophysics Data System (ADS)

    Westerhoff, T.; Davis, M.; Hartmann, P.; Hull, T.; Jedamzik, R.

    2014-07-01

    The glass ceramic ZERODUR® from SCHOTT has an excellent reputation as mirror blank material for earthbound and space telescope applications. It is known for its extremely low coefficient of thermal expansion (CTE) at room temperature and its excellent CTE homogeneity. Recent improvements in CNC machining at SCHOTT allow achieving extremely light weighted substrates up to 90% incorporating very thin ribs and face sheets. In 2012 new ZERODUR® grades EXPANSION CLASS 0 SPECIAL and EXTREME have been released that offer the tightest CTE grades ever. With ZERODUR® TAILORED it is even possible to offer ZERODUR® optimized for customer application temperature profiles. In 2013 SCHOTT started the development of a new dilatometer setup with the target to drive the industrial standard of high accuracy thermal expansion metrology to its limit. In recent years SCHOTT published several paper on improved bending strength of ZERODUR® and lifetime evaluation based on threshold values derived from 3 parameter Weibull distribution fitted to a multitude of stress data. ZERODUR® has been and is still being successfully used as mirror substrates for a large number of space missions. ZERODUR® was used for the secondary mirror in HST and for the Wolter mirrors in CHANDRA without any reported degradation of the optical image quality during the lifetime of the missions. Some years ago early studies on the compaction effects of electron radiation on ZERODUR® were re analyzed. Using a more relevant physical model based on a simplified bimetallic equation the expected deformation of samples exposed in laboratory and space could be predicted in a much more accurate way. The relevant ingredients for light weighted mirror substrates are discussed in this paper: substrate material with excellent homogeneity in its properties, sufficient bending strengths, space radiation hardness and CNC machining capabilities.

  8. B cells expressing IL-10 mRNA modulate memory T cells after DNA-Hsp65 immunization

    PubMed Central

    Fontoura, I. C.; Trombone, A.P.F.; Almeida, L. P.; Lorenzi, J. C. C.; Rossetti, R. A. M.; Malardo, T.; Padilha, E.; Schluchting, W.; Silva, R. L. L.; Gembre, A. F.; Fiuza, J. E. C.; Silva, C. L.; Panunto-Castelo, A.; Coelho-Castelo, A. A. M.

    2015-01-01

    In DNA vaccines, the gene of interest is cloned into a bacterial plasmid that is engineered to induce protein production for long periods in eukaryotic cells. Previous research has shown that the intramuscular immunization of BALB/c mice with a naked plasmid DNA fragment encoding the Mycobacterium leprae 65-kDa heat-shock protein (pcDNA3-Hsp65) induces protection against M. tuberculosis challenge. A key stage in the protective immune response after immunization is the generation of memory T cells. Previously, we have shown that B cells capture plasmid DNA-Hsp65 and thereby modulate the formation of CD8+ memory T cells after M. tuberculosis challenge in mice. Therefore, clarifying how B cells act as part of the protective immune response after DNA immunization is important for the development of more-effective vaccines. The aim of this study was to investigate the mechanisms by which B cells modulate memory T cells after DNA-Hsp65 immunization. C57BL/6 and BKO mice were injected three times, at 15-day intervals, with 100 µg naked pcDNA-Hsp65 per mouse. Thirty days after immunization, the percentages of effector memory T (TEM) cells (CD4+ and CD8+/CD44high/CD62Llow) and memory CD8+ T cells (CD8+/CD44high/CD62Llow/CD127+) were measured with flow cytometry. Interferon γ, interleukin 12 (IL-12), and IL-10 mRNAs were also quantified in whole spleen cells and purified B cells (CD43−) with real-time qPCR. Our data suggest that a B-cell subpopulation expressing IL-10 downregulated proinflammatory cytokine expression in the spleen, increasing the survival of CD4+ TEM cells and CD8+ TEM/CD127+ cells. PMID:26397973

  9. Hubble Space Telescope Near-Ultraviolet Spectroscopy of Bright CEMP-s Stars

    NASA Astrophysics Data System (ADS)

    Placco, Vinicius M.; Beers, Timothy C.; Ivans, Inese I.; Filler, Dan; Imig, Julie A.; Roederer, Ian U.; Abate, Carlo; Hansen, Terese; Cowan, John J.; Frebel, Anna; Lawler, James E.; Schatz, Hendrik; Sneden, Christopher; Sobeck, Jennifer S.; Aoki, Wako; Smith, Verne V.; Bolte, Michael

    2015-10-01

    We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the bright carbon-enhanced metal-poor (CEMP) stars HD 196944 (V=8.40, [Fe/H] = -2.41) and HD 201626 (V=8.16, [Fe/H] = -1.51), based on data acquired with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope. Both of these stars belong to the sub-class CEMP-s, and exhibit clear over-abundances of heavy elements associated with production by the slow neutron-capture process. HD 196944 has been well-studied in the optical region, but we add abundance results for six species (Ge, Nb, Mo, Lu, Pt, and Au) that are only accessible in the NUV. In addition, we provide the first determination of its orbital period, P = 1325 days. HD 201626 has only a limited number of abundance results based on previous optical work—here we add five new species from the NUV, including Pb. We compare these results with models of binary-system evolution and s-process element production in stars on the asymptotic giant branch, with the goal of explaining their origin and evolution. Our best-fitting models for HD 196944 ({M}1,i=0.9{M}⊙ , {M}2,i=0.86{M}⊙ , for [Fe/H] = -2.2), and HD 201626 ({M}1,i=0.9{M}⊙ , {M}2,i=0.76{M}⊙ , for [Fe/H] = -2.2; {M}1,i=1.6{M}⊙ , {M}2,i=0.59{M}⊙ , for [Fe/H] = -1.5) are consistent with the current accepted scenario for the formation of CEMP-s stars. The data presented herein were obtained with the (i) NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. (These observations are associated with program GO-12554, data sets OBQ601010-30 and OBQ602010-30.); and (ii) W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. (The Observatory was made

  10. Prism beamswitch for radio telescopes.

    PubMed

    Payne, J M; Ulich, B L

    1978-12-01

    A dielectric prism and switching mechanism have been constructed for beamswitching a Cassegrain radio telescope. Spatially extended radio sources may be mapped without significant confusion utilizing the sensitivity and stability inherent in the conventional Dicke radiometer.

  11. Automated telescope for variability studies

    NASA Astrophysics Data System (ADS)

    Ganesh, S.; Baliyan, K. S.; Chandra, S.; Joshi, U. C.; Kalyaan, A.; Mathur, S. N.

    PRL has installed a 50 cm telescope at Mt Abu, Gurushikhar. The backend instrument consists of a 1K × 1K EMCCD camera with standard UBVRI filters and also has polarization measurement capability using a second filter wheel with polaroid sheets oriented at different position angles. This 50 cm telescope observatory is operated in a robotic mode with different methods of scheduling of the objects being observed. This includes batch mode, fully manual as well as fully autonomous mode of operation. Linux based command line as well as GUI software are used entirely in this observatory. This talk will present the details of the telescope and associated instruments and auxiliary facilities for weather monitoring that were developed in house to ensure the safe and reliable operation of the telescope. The facility has been in use for a couple of years now and various objects have been observed. Some of the interesting results will also be presented.

  12. Anastigmatic three-mirror telescope

    NASA Technical Reports Server (NTRS)

    Korsch, D. G. (Inventor)

    1978-01-01

    A three-mirror telescope for extraterrestrial observations is described. An ellipsoidal primary mirror, a hyperbolic secondary mirror, and an ellipsoidal tertiary mirror, produce an image in a conveniently located finite plane for viewing.

  13. Space Telescope moving target tracking

    NASA Technical Reports Server (NTRS)

    Strikwerda, T. E.; Strohbehn, K.; Fowler, K. R.; Skillman, D. R.

    1985-01-01

    This paper formulates a Space Telescope (ST) moving target tracking algorithm and evaluates a practical implementation. The algorithm is shown to be satisfactory for tracking such moving objects as the moons of Mars.

  14. Large aperture Fresnel telescopes/011

    SciTech Connect

    Hyde, R.A., LLNL

    1998-07-16

    At Livermore we`ve spent the last two years examining an alternative approach towards very large aperture (VLA) telescopes, one based upon transmissive Fresnel lenses rather than on mirrors. Fresnel lenses are attractive for VLA telescopes because they are launchable (lightweight, packagable, and deployable) and because they virtually eliminate the traditional, very tight, surface shape requirements faced by reflecting telescopes. Their (potentially severe) optical drawback, a very narrow spectral bandwidth, can be eliminated by use of a second (much smaller) chromatically-correcting Fresnel element. This enables Fresnel VLA telescopes to provide either single band ({Delta}{lambda}/{lambda} {approximately} 0.1), multiple band, or continuous spectral coverage. Building and fielding such large Fresnel lenses will present a significant challenge, but one which appears, with effort, to be solvable.

  15. Innovative approaches to exoplanet detection and characterization: Notes from the Nov 10-13 Keck Institute for Space Studies workshop

    NASA Astrophysics Data System (ADS)

    Young, Eliot; Traub, Wesley; Unwin, Stephen; Stapelfeldt, Karl

    2010-05-01

    A four-day workshop was convened on November 10-13, 2009 by the Keck Institute for Space Studies and JPL to consider innovative approaches to detecting and characterizing exoplanets and planetary systems. The program and many of the presentations can be found online: . We present some of the observational strategies discussed in this workshop and summarize some of the issues associated with them. In particular, we will highlight some of the advantages and shortcomings of suborbital and orbital (e.g., ESPA rings) observing platforms in the context of exoplanet detection and characterization.

  16. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This illustration depicts a side view of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  17. The Large Binocular Telescope Project

    NASA Astrophysics Data System (ADS)

    Hill, J. M.

    1994-12-01

    The Large Binocular Telescope (LBT) Project has evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 x 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astronomico di Arcetri and the Research Corporation based in Tucson. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train --- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in late fall 1995 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximum flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1995 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson) and ADS Italia. Construction

  18. The Large Binocular Telescope Project

    NASA Astrophysics Data System (ADS)

    Hill, J. M.

    1995-05-01

    The Large Binocular Telescope (LBT) Project has evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 x 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train --- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in spring of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximicrons flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximicrons stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1995 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson) and ADS Italia

  19. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is a cutaway illustration of the Hubble Space Telescope (HST) with callouts. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  20. Hubble Space Telescope-Concept

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is an artist's concept of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.