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Sample records for infrared interferometric telescope

  1. The Space Infrared Interferometric Telescope (SPIRIT)

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2007-01-01

    The Space Infrared Interferometric Telescope (SPIRIT) is a candidate NASA Origins Probe Mission. SPIRIT is a two-telescope Michelson interferometer covering wavelengths from 25-400 microns, providing simultaneously high spectral resolution and high angular resolution. With comparable sensitivity to Spitzer, but two orders of magnitude improvement in angular resolution, SPIRIT will enable us to address a wide array of compelling scientific questions, including how planetary systems form in disks and how new planets interact with the disk. Further, SPIRIT will lay the technological groundwork for an array of future interferometry missions with ambitious scientific goals, including the Terrestrial Planet Finder Interferometer / Darwin, and the Submillimeter Probe of the Evolution of Cosmic Structure.

  2. The Space Infrared Interferometric Telescope (SPIRIT)

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2007-01-01

    The Space Infrared Interferometric Telescope (SPIRIT) is a candidate NASA Origins Probe Mission. SPIRIT is a two-telescope Michelson interferometer covering wavelengths from 25-400 microns, providing simultaneously high spectral resolution and high angular resolution. With comparable sensitivity to Spitzer, but two orders of magnitude improvement in angular resolution, SPIRIT will enable us to address a wide array of compelling scientific questions, including how planetary systems form in disks and how new planets interact with the disk. Further, SPIRIT will lay the technological groundwork for an array of future interferometry missions with ambitious scientific goals, including the Terrestrial Planet Finder Interferometer/Darwin, and the Submillimeter Probe of the Evolution of Cosmic Structure.

  3. The Space Infrared Interferometric Telescope (SPIRIT)

    NASA Technical Reports Server (NTRS)

    Leisawitz, David T.

    2014-01-01

    The far-infrared astrophysics community is eager to follow up Spitzer and Herschel observations with sensitive, high-resolution imaging and spectroscopy, for such measurements are needed to understand merger-driven star formation and chemical enrichment in galaxies, star and planetary system formation, and the development and prevalence of water-bearing planets. The Space Infrared Interferometric Telescope (SPIRIT) is a wide field-of-view space-based spatio-spectral interferometer designed to operate in the 25 to 400 micron wavelength range. This talk will summarize the SPIRIT mission concept, with a focus on the science that motivates it and the technology that enables it. Without mentioning SPIRIT by name, the astrophysics community through the NASA Astrophysics Roadmap Committee recently recommended this mission as the first in a series of space-based interferometers. Data from a laboratory testbed interferometer will be used to illustrate how the spatio-spectral interferometry technique works.

  4. System Engineering the Space Infrared Interferometric Telescope (SPIRIT)

    NASA Technical Reports Server (NTRS)

    Hyde, Tristram T.; Leisawitz, David T.; Rinehart, Stephen

    2007-01-01

    The Space Infrared Interferometric Telescope (SPIRIT) was designed to accomplish three scientific objectives: (1) learn how planetary systems form from protostellar disks and how they acquire their inhomogeneous chemical composition; (2) characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different types form; and (3) learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. SPIRIT will accomplish these objectives through infrared observations with a two aperture interferometric instrument. This paper gives an overview of SPIRIT design and operation, and how the three design cycle concept study was completed. The error budget for several key performance values allocates tolerances to all contributing factors, and a performance model of the spacecraft plus instrument system demonstrates meeting those allocations with margin.

  5. Development of the Far-Infrared Interferometric Telescope Experiment

    NASA Astrophysics Data System (ADS)

    Kanoh, T.; Shibai, H.; Fukagawa, M.; Matsuo, T.; Kato, E.; Itoh, Y.; Kawada, M.; Watabe, T.; Kohyama, T.; Matsumoto, Y.; Morishita, H.; Yamamoto, K.; Kanoh, R.; Nakashima, A.; Tanabe, M.; Narita, M.

    2009-08-01

    We have developed the Far-Infrared Interferometric Telescope Experiment (FITE). It will be the first astronomical infrared interferometer working in space. FITE is a balloon-borne telescope, and will operate in the stratosphere (at an altitude of 35 kilometers). FITE is a Michelson-type stellar interferometer, and has a long baseline of 20 meters (at maximum). The purpose of the FITE project is to achieve a high spatial resolution of 1 arcsecond at a wavelength of 100 micrometers. For its first flight, FITE has an 8-meter baseline, and the aim is to measure the interference fringes with a spatial resolution of 2.5 arcseconds. In order to achieve this aim, the two beams must be focused within 2.5 arcseconds accuracy in the imaging quality, within 10 arcseconds of accuracy in the beam alignment, and within 30 micrometers accuracy in the optical path length between the two beams. Also, the orientation of the telescope must be controlled within 2.5 arcseconds accuracy. To achieve such accuracy, the structural parts of the telescope are made of carbon-fiber reinforced plastics that have very low thermal expansion coefficient and a large Young's modulus. During observation, the optical alignment is actively adjusted by the alignment mechanisms. We also adopt a three-axis attitude control system to stabilize the orientation of the telescope with high accuracy. FITE is a very unique approach, and it serves as a step in the further development of larger-scale infrared interferometry in space.

  6. Far-Infrared Interferometric Telescope Experiment : I. Interferometer Optics

    NASA Astrophysics Data System (ADS)

    Kato, Eri; Shibai, Hiroshi; Kawada, Mitsunobu; Narita, Masanao; Matsuo, Taro; Ohkubo, Atsushi; Suzuki, Miki; Kanoh, Tetsuo; Yamamoto, Koudai; Fite Team

    We have developed a far-infrared interferometer (Far-Infrared Interferometric Telescope Experiment: FITE). It will be the first astronomical infrared interferometer working in space. FITE is a balloon-borne telescope, and operated in the stratosphere (the altitude of 35 km). The aim of the FITE project is to achieve a high spatial resolution of 1 arcsecond at the wavelength of 100 micrometers. FITE is a Michelson stellar interferometer, and is able to realize a long base line beyond the size of the collecting mirror by using four plane mirrors. The first flight is scheduled for November 2008 in Brazil, and the aim is to measure the interference fringes with a spatial resolution of 2.5 arcseconds. In order to achieve this, the two beams must be focused within 2.5 arcsecond accuracy in the imaging quality, within 10 arcsecond accuracy in the beam alignment and within 30 micrometers accuracy in the optical path length between the two beams. In order to archive these accuracies, the structural parts of the telescope were made of carbon-fiber reinforced plastics, which have very low thermal expansion coefficient and large Young's modulus. During observation of a target, the optical alignment is actively adjusted and the orientation of the telescope is stabilized by the three-axis control.

  7. The Space Infrared Interferometric Telescope (SPIRIT): Optical System Design Considerations

    NASA Technical Reports Server (NTRS)

    Wilson, Mark E.; Leisawitz, David; Martino, Anthony J.; Budinoff, Jason; Quijada, Manuel; Hyde, Tupper

    2007-01-01

    SPIRIT is a candidate NASA Origins Probe mission. It is a spatial and spectral interferometer operating at 4 K with an operating wavelength range 25 - 400 microns. This paper describes the various components of the candidate optical system, including telescopes, pointing and tracking optics, along with their functions. Some of the tradeoffs involved in selecting various components, with their particular characteristics, are described.

  8. 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.

  9. The Space Infrared Interferometric Telescope (SPIRIT): The Mission Design Solution Space and the Art of the Possible

    NASA Technical Reports Server (NTRS)

    Leisawitz, David; Hyde, T. Tupper; Rinehart, Stephen A.; Weiss, Michael

    2008-01-01

    Although the Space Infrared Interferometric Telescope (SPIRIT) was studied as a candidate NASA Origins Probe mission, the real world presents a broader set of options, pressures, and constraints. Fundamentally, SPIRIT is a far-IR observatory for high-resolution imaging and spectroscopy designed to address a variety of compelling scientific questions. How do planetary systems form from protostellar disks, dousing some planets in water while leaving others dry? Where do planets form, and why are some ice giants while others are rocky? How did high-redshift galaxies form and merge to form the present-day population of galaxies? This paper takes a pragmatic look at the mission design solution space for SPIRIT, presents Probe-class and facility-class mission scenarios, and describes optional design changes. The costs and benefits of various mission design alternatives are roughly evaluated, giving a basis for further study and to serve as guidance to policy makers.

  10. The Space Infrared Interferometric Telescope (SPIRIT): High-resolution Imaging and Spectroscopy in the Far-infrared

    NASA Technical Reports Server (NTRS)

    Leisawitz, D,; Baker, G.; Barger, A.; Benford, D.; Blain, A; Boyle, R.; Broderick, R.; Budinoff, J.; Carpenter, J.; Caverly, R.; Chen, P.; Cooley, S.; Cottingham, C.; Crooke, J.; DiPietro, D.; Femiano, M.; Ferrer, A.; Fischer, J.; Gardner, J.; Hallock, L.; Harris, K.; Hartman, K.; Harwit, M.; Hillenbrand, L.; Hyde, T.

    2007-01-01

    We report results of a recently-completed study of SPIRIT, a candidate NASA Origins Probe. SPIRIT is a spatial and spectral interferometer with an operating wavelength range 25 - 400 microns. SPIRIT will provide sub-arcsecond resolution images and spectra with resolution R = 3000 in a 1 arcmin field of view to accomplish three primary scientific objectives: (1) Learn how planetary systems form from protostellar disks, and how they acquire their chemical organization; (2) Characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets form, and why some planets are ice giants and others are rocky; and (3) Learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. Observations with SPIRIT will be complementary to those of the James Webb Space Telescope and the ground-based Atacama Large Millimeter Array. All three observatories could be operational contemporaneously. SPIRIT will pave the way to the 1 km maximum baseline interferometer known as the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS). In addition to the SPIRIT mission concept, this talk will emphasize the importance of dense u-v plane coverage and describe some of the practical considerations associated with alternative interferometric baseline sampling schemes.

  11. 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.

  12. The Space Infrared Interferometric Telescope (SPIRIT) and its Complementarity to ALMA

    NASA Technical Reports Server (NTRS)

    Leisawitz, Dave

    2007-01-01

    We report results of a pre-Formulation Phase study of SPIRIT, a candidate NASA Origins Probe mission. SPIRIT is a spatial and spectral interferometer with an operating wavelength range 25 - 400 microns. SPIRIT will provide sub-arcsecond resolution images and spectra with resolution R = 3000 in a 1 arcmin field of view to accomplish three primary scientific objectives: (1) Learn how planetary systems form from protostellar disks, and how they acquire their chemical organization; (2) Characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different types form; and (3) Learn how high-redshift galaxies formed and merged to form the present-day population of galaxies. In each of these science domains, SPIRIT will yield information complementary to that obtainable with the James Webb Space Telescope (JWST)and the Atacama Large Millimeter Array (ALMA), and all three observatories could operate contemporaneously. Here we shall emphasize the SPIRIT science goals (1) and (2) and the mission's complementarity with ALMA.

  13. 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.

  14. Note: Near infrared interferometric silicon wafer metrology.

    PubMed

    Choi, M S; Park, H M; Joo, K N

    2016-04-01

    In this investigation, two near infrared (NIR) interferometric techniques for silicon wafer metrology are described and verified with experimental results. Based on the transparent characteristic of NIR light to a silicon wafer, the fiber based spectrally resolved interferometry can measure the optical thickness of the wafer and stitching low coherence scanning interferometry can reconstruct entire surfaces of the wafer.

  15. 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.

  16. Integrated optics interferometric four telescopes nuller

    NASA Astrophysics Data System (ADS)

    Errmann, Ronny; Minardi, Stefano; Labadie, Lucas; Dreisow, Felix; Nolte, Stefan; Pertsch, Thomas

    2014-07-01

    Nulling interferometry has been identified as a competitive technique for the detection of extrasolar planets. The technique consists in combining out-of-phase pairs of telescopes to null effectively the light of a bright star an reveal the dim glow of the companion. We have manufactured and tested with monochromatic light an integrated optics component which combines a linear array of 4 telescopes in the nulling mode envisaged by Angel&Wolf.1 Our testbench simulates the motion of a star in the sky. The tests have demonstrated a nulling scaling as the fourth power of the baseline delay.

  17. Space Infrared Telescope Facility science instruments overview

    NASA Technical Reports Server (NTRS)

    Bothwell, Mary

    1991-01-01

    The Space Infrared Telescope Facility (SIRTF) will contain three cryogenically cooled infrared instruments: the Infrared Array Camera (IRAC), the Infrared Spectrograph (IRS), and the Multiband Infrared Photometer for SIRTF (MIPS). These instruments are sensitive to infrared radiation in the 1.8-1,200 micrometer range. This paper will discuss the three instruments' functional requirements and their accommodation in the SIRTF telescope system.

  18. LOITA: Lunar Optical/Infrared Telescope Array

    NASA Technical Reports Server (NTRS)

    1993-01-01

    LOITA (Lunar Optical/Infrared Telescope Array) is a lunar-based interferometer composed of 18 alt-azimuth telescopes arranged in a circular geometry. This geometry results in excellent uv coverage and allows baselines up to 5 km long. The angular resolution will be 25 micro-arcsec at 500 nm and the main spectral range of the array will be 200 to 1100 nm. For infrared planet detection, the spectral range may be extended to nearly 10 mu m. The telescope mirrors have a Cassegrain configuration using a 1.75 m diameter primary mirror and a 0.24 m diameter secondary mirror. A three-stage (coarse, intermediate, and fine) optical delay system, controlled by laser metrology, is used to equalize path lengths from different telescopes to within a few wavelengths. All instruments and the fine delay system are located within the instrument room. Upon exiting the fine delay system, all beams enter the beam combiner and are then directed to the various scientific instruments and detectors. The array instrumentation will consist of CCD detectors optimized for both the visible and infrared as well as specially designed cameras and spectrographs. For direct planet detection, a beam combiner employing achromatic nulling interferometry will be used to reduce star light (by several orders of magnitude) while passing the planet light. A single telescope will be capable of autonomous operation. This telescope will be equipped with four instruments: wide field and planetary camera, faint object camera, high resolution spectrograph, and faint object spectrograph. These instruments will be housed beneath the telescope. The array pointing and control system is designed to meet the fine pointing requirement of one micro-arcsec stability and to allow precise tracking of celestial objects for up to 12 days. During the lunar night, the optics and the detectors will be passively cooled to 70-80 K temperature. To maintain a continuous communication with the earth a relay satellite placed at the L4

  19. A novel lightweight Fizeau infrared interferometric imaging system

    NASA Astrophysics Data System (ADS)

    Hope, Douglas A.; Hart, Michael; Warner, Steve; Durney, Oli; Romeo, Robert

    2016-05-01

    Aperture synthesis imaging techniques using an interferometer provide a means to achieve imagery with spatial resolution equivalent to a conventional filled aperture telescope at a significantly reduced size, weight and cost, an important implication for air- and space-borne persistent observing platforms. These concepts have been realized in SIRII (Space-based IR-imaging interferometer), a new light-weight, compact SWIR and MWIR imaging interferometer designed for space-based surveillance. The sensor design is configured as a six-element Fizeau interferometer; it is scalable, light-weight, and uses structural components and main optics made of carbon fiber replicated polymer (CFRP) that are easy to fabricate and inexpensive. A three-element prototype of the SIRII imager has been constructed. The optics, detectors, and interferometric signal processing principles draw on experience developed in ground-based astronomical applications designed to yield the highest sensitivity and resolution with cost-effective optical solutions. SIRII is being designed for technical intelligence from geo-stationary orbit. It has an instantaneous 6 x 6 mrad FOV and the ability to rapidly scan a 6x6 deg FOV, with a minimal SNR. The interferometric design can be scaled to larger equivalent filled aperture, while minimizing weight and costs when compared to a filled aperture telescope with equivalent resolution. This scalability in SIRII allows it address a range of IR-imaging scenarios.

  20. Common-Path Interferometric Wavefront Sensing for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Wallace, James Kent

    2011-01-01

    This paper presents an optical configuration for a common-path phase-shifting interferometric wavefront sensor.1 2 This sensor has a host of attractive features which make it well suited for space-based adaptive optics. First, it is strictly reflective and therefore operates broadband, second it is common mode and therefore does not suffer from systematic errors (like vibration) that are typical in other interferometers, third it is a phase-shifting interferometer and therefore benefits from both the sensitivity of interferometric sensors as well as the noise rejection afforded by synchronous detection. Unlike the Shack-Hartman wavefront sensor, it has nearly uniform sensitivity to all pupil modes. Optical configuration, theory and simulations for such a system will be discussed along with predicted performance.

  1. 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.

  2. Science with the Space Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Roellig, Thomas L.

    2003-01-01

    The Space Infrared Telescope Facility (SIRTF), the fourth and final member of NASA's series of Great Observatories, is scheduled to launch on April 15,2003. Together with the Hubbie Space Telescope, the Compton Gamma ray Telescope, and the Chandra X-Ray Telescope this series of observatories offers observational capabilities across the electromagnetic spectrum from the infrared to high-energy gamma rays. SIRTF is based on three focal plane instruments - an infrared spectrograph and two infrared imagers - coupled to a superfluid-helium cooled telescope to achieve unprecedented sensitivity from 3 to 180 microns. Although SIRTF is a powerful general-purpose infrared observatory, its design was based on the capability to address four broad science themes: (1) understanding the structure and composition of the early universe, (2) understanding the nature of brown dwarfs and super-planets, (3) probing protostellar, protoplanetary, and planetary debris disk systems, and (4) understanding the origin and structure of ultraluminous infrared galaxies and active galactic nuclei. This talk will address the design and capabilities of the SIRTF observatory, provide an overview of some of the initial science investigations planned by the SIRTF Guaranteed Time Observers, and give a brief overview of the General Observer proposal process.

  3. Spacelab 2 infrared telescope cryogenic system

    NASA Technical Reports Server (NTRS)

    Urban, E. W.; Katz, L.; Hendricks, J. B.; Karr, G. R.

    1979-01-01

    The paper discusses the development of a cryogenic helium system to provide cooling to a scanning infrared telescope for the Spacelab 2 mission. The infrared optical/detector system and related electronics are being developed by the Smithsonian Astrophysical Observatory and the University of Arizona. A superfluid helium dewar and porous plug phase separator permit gas cooling of the infrared focal plane assembly to about 2.5 K, and of the two telescope sections to 8 K and 60 K. The design of the cryogenic system,including a commandable vacuum cover, and the prelaunch liquid helium servicing and maintenance approach were discussed. It is concluded that the system will satisfy the Infrared Telescope requirements, and the superfluid helium system shall be capable of satisfying cryogenic helium cooled requirements for the next several years.

  4. The Infrared Telescope in Space (IRTS)

    NASA Technical Reports Server (NTRS)

    Murakami, H.; Bock, J.; Freund, M. M.; Guo, H.; Hirao, T.; Lange, A. E.; Matsuhara, H.; Matsumoto, T.; Matsuura, S.; Mcmahon, T. J.

    1994-01-01

    The Infrared Telescope in Space (IRTS) is a cryogenically cooled small infrared telescope that will fly aboard the small space platform Space Flyer Unit. It will survey approximately 10% of the sky with a relatively wide beam during its 20 day emission. Four focal-plane instruments will make simultaneous observations of the sky at wavelengths ranging from 1 to 1000 microns. The IRTS will provide significant information on cosmology, interstellar matter, late-type stars, and interplanetary dust. This paper describes the instrumentation and mission.

  5. Support structures for large infrared telescopes

    NASA Technical Reports Server (NTRS)

    Hedgepeth, J. M.

    1984-01-01

    An infrared telescope requires an accuracy of its reflecting surfaces of less than a micrometer. Future missions may require such accuracy from telescopes that are 20 meters or larger in diameter. The structure for supporting such a telescope will most probably take the form of a deep truss. Various approaches for constructing the primary mirror in space are illustrated. One that employs automated deployment of interconnected reflector-structure modules was described in detail. Estimates were made of the precision obtainable with properly configured truss structures and the required ability of active control systems for achieving the desired accuracy.

  6. Concurrent engineering of an infrared telescope system

    NASA Astrophysics Data System (ADS)

    Geis, Jason; Lang, Jeffrey; Peterson, Leslie; Roybal, Francisco; Tanzillo, Jennifer; Thomas, David; Warren, David

    2011-10-01

    A concurrent engineering approach to the design and analysis of a space-borne Electro-Optical (EO) sensor is presented. A detailed design of an infrared telescope payload is developed by an interdisciplinary team of mechanical, structural, thermal, and optical engineers using a Simulation Driven Engineering (SDE) software environment. The telescope payload design is also integrated with a conceptual level design of the space segment of a mission that incorporates the payload. The flow of the concurrent design process is described, and design outputs are provided.

  7. Cryogenic infrared imaging beryllium telescope for Infrared Astronomical Satellite (IRAS)

    NASA Technical Reports Server (NTRS)

    Devereux, W. P.

    1983-01-01

    The IRAS mission is the result of an international project involving the cooperation of the U.S., the United Kingdom, and the Netherlands. The Infrared Astronmical Satellite was placed into orbit on January 25, 1983. Its main function is to provide a survey of the entire sky as viewed in four octaves of infrared radiation in the wavelenth region from 8 to 120 microns. The cylindrical structure of the satellite contains a large dewar vessel with 70 liters of superfluid helium. The helium has the function to maintain the contents of the vessel at 2.5 K for the duration of the mission. The IRAS optics is a Ritchey-Chretien telescope of 24 inches aperture. Because of the operational requirements of the mission, it had been specified that all optical components should be beryllium. Attention is given to the cold performance test conducted with IRAS, plans for future infrared telescopes, and reflectance limits.

  8. The Space Infrared Interferometric Telescope (SPIRIT): Mission Study Results

    DTIC Science & Technology

    2006-01-01

    organization; (2) Characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets...and how they acquire their chemical organization; (2) Characterize the family of extrasolar planetary systems by imaging the structure in debris...protostellar disks, and how they acquire their chemical organization; (2) characterize the family of extrasolar planetary systems by imaging the structure in

  9. SOFIA (Stratospheric Observatory For Infrared Astronomy) with Telescope Configuration Changes

    NASA Technical Reports Server (NTRS)

    2001-01-01

    SOFIA (Stratospheric Observatory For Infrared Astronomy) with Telescope Configuration Changes Artwork. Concepts: Based on 18 Years of Experience of Kuiper Airborne Observatory (KAO) Operation, Characteristics, Operations and Science

  10. Very long baseline interferometric observations made with an orbiting radio telescope

    NASA Technical Reports Server (NTRS)

    Levy, G. S.; Linfield, R. P.; Ulvestad, J. S.; Edwards, C. D.; Jordan, J. F., Jr.; Di Nardo, J.; Christensen, C. S.; Preston, R. A.; Skjerve, L. J.; Blaney, K. B.

    1986-01-01

    An orbiting spacecraft and ground observatories have been used to obtain interferometric observations of cosmic radio sources. The Tracking and Data Relay Satellite System (TDRSS) was used as the orbiting observatory in conjunction with two 64-meter radio telescopes at ground observatories, one in Australia and one in Japan. The quasars 1730-130 (NRAO 530), 1510-089, and 1741-038 were observed at a frequency of 2.3 gigahertz, and a maximum projected baseline of 1.4 earth diameters was achieved. All quasar observations for which valid data were acquired resulted in detected fringes. Many of the techniques proposed for a dedicated very long baseline interferometry observatory in space were used successfully in this experiment.

  11. Very long baseline interferometric observations made with an orbiting radio telescope.

    PubMed

    Levy, G S; Linfield, R P; Ulvestad, J S; Edwards, C D; Jordan, J F; DI Nardo, S J; Christensen, C S; Preston, R A; Skjerve, L J; Stavert, L R; Burke, B F; Whitney, A R; Cappallo, R J; Rogers, A E; Blaney, K B; Maher, M J; Ottenhoff, C H; Jauncey, D L; Peters, W L; Nishimura, T; Hayashi, T; Takano, T; Yamada, T; Hirabayashi, H; Morimoto, M; Inoue, M; Shiomi, T; Kawaguchi, N; Kunimori, H

    1986-10-10

    An orbiting spacecraft and ground observatories have been used to obtain interferometric observations of cosmic radio sources. The Tracking and Data Relay Satellite System (TDRSS) was used as the orbiting observatory in conjunction with two 64- meter radio telescopes at ground observatories, one in Australia and one in Japan. The quasars 1730-130 (NRAO 530), 1510-089, and 1741-038 were observed at a frequency of 2.3 gigahertz, and a maximum projected baseline of 1.4 earth diameters was achieved. All quasar observations for which valid data were acquired resulted in detected fringes. Many of the techniques proposed for a dedicated very long baseline interferometry observatory in space were used successfully in this experiment.

  12. Space infrared telescope pointing control system. Automated star pattern recognition

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Vanbezooijen, R. W. H.

    1985-01-01

    The Space Infrared Telescope Facility (SIRTF) is a free flying spacecraft carrying a 1 meter class cryogenically cooled infrared telescope nearly three oders of magnitude most sensitive than the current generation of infrared telescopes. Three automatic target acquisition methods will be presented that are based on the use of an imaging star tracker. The methods are distinguished by the number of guidestars that are required per target, the amount of computational capability necessary, and the time required for the complete acquisition process. Each method is described in detail.

  13. GIRL: German Infrared Laboratory. Telescope study, phase B

    NASA Technical Reports Server (NTRS)

    Schlegelmilch, R.; Zeiss, C.

    1981-01-01

    The construction and mounting of mirrors for an infrared telescope are described. Tests conducted to determine the thermal and stress characteristics of various types of mounting for main and collection mirrors are also discussed.

  14. Two-channel interferometric detection for the compensation of phase fluctuation noise in nonlinear infrared microscopy

    NASA Astrophysics Data System (ADS)

    Lee, E. S.; Lee, S. W.; Park, J. H.; Lee, J. Y.

    2013-01-01

    We demonstrate an interferometric implementation of nonlinear optical infrared microscopy in which a probe beam interrogates the refractive index change of samples that is induced by molecular vibrational absorption of an infrared pump beam. To compensate for the phase noise caused by the ambient airflow and external vibration, we configure two coupled Mach-Zehnder interferometers sharing a single microscope setup in the sample arm. Proper control over the phase between the two interference channels allows two simultaneous quadrature mode outputs. The validity of our method is proven by imaging polystyrene bead aggregates and comparing the images with the conventional single-channel results.

  15. Coordinate interferometric system for measuring the position of a sample with infrared telecom laser diode

    NASA Astrophysics Data System (ADS)

    Holá, Miroslava; Lazar, Josef; Čížek, Martin; Hucl, Václav; Řeřucha, Šimon; Číp, Ondřej

    2016-11-01

    We report on a design of an interferometric position measuring system for control of a sample stage in an e-beam writer with reproducibility of the position on nanometer level and resolution below nanometer. We introduced differential configuration of the interferometer where the position is measured with respect to a central reference point to eliminate deformations caused by thermal and pressure effects on the vacuum chamber. The reference is here the electron gun of the writer. The interferometer is designed to operate at infrared, telecommunication wavelength due to the risk of interference of stray light with sensitive photodetectors in the chamber. The laser source is here a narrow-linewidth DFB laser diode with electronics of our own design offering precision and stability of temperature and current, low-noise, protection from rf interference, and high-frequency modulation. Detection of the interferometric signal relies on a novel derivative technique utilizing hf frequency modulation and phase-sensitive detection.

  16. Infrared Astronomy Professional Development for K-12 Educators: WISE Telescope

    NASA Astrophysics Data System (ADS)

    Borders, Kareen; Mendez, B. M.

    2010-01-01

    K-12 educators need effective and relevant astronomy professional development. WISE Telescope (Wide-Field Infrared Survey Explorer) and Spitzer Space Telescope Education programs provided an immersive teacher professional development workshop at Arecibo Observatory in Puerto Rico during the summer of 2009. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers built and used basic telescopes, learned about the history of telescopes, explored ground and satellite based telescopes, and explored and worked on models of WISE Telescope. An in-depth explanation of WISE and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of WISE lenticulars and diagramming of infrared data, listening to light by using speakers hooked up to photoreceptor cells, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars. We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development. Funding was provided by WISE Telescope, Spitzer Space Telescope, Starbucks, Arecibo Observatory, the American Institute of Aeronautics and Astronautics, and the Washington Space Grant Consortium.

  17. MegaMIR: The Megapixel Mid-Infrared Instrument for the Large Binocular Telescope Interferometer

    NASA Technical Reports Server (NTRS)

    Mainzer, Amanda K.; Young, Erick; Hong, John; Werner, Mike; Hinz, Phil; Gorjan, Varoujan; Ressler, Michael E.

    2006-01-01

    The Megapixel Mid-infrared Instrument (MegaMIR) is a proposed Fizeau-mode camera for the Large Binocular Telescope operating at wavelengths between 5 and 28 micrometers. The camera will be used in conjunction with the Large Binocular Telescope Interferometer (LBTI), a cryogenic optical system that combines the beams from twin 8.4-m telescopes in a phase coherent manner. Unlike other interferometric systems, the co-mounted telescopes on the LBT satisfy the sine condition, providing diffraction-limited resolution over the 40" field of view of the camera. With a 22.8-m baseline, MegaMIR will yield 0.1" angular resolution, making it the highest resolution wide field imager in the thermal infrared for at least the next decade. MegaMIR will utilize a newly developed 1024 x 1024 pixel Si:As detector array that has been optimized for use at high backgrounds. This new detector is a derivative of the Wide-field Infrared Survey Explorer (WISE) low-background detector. The combination of high angular resolution and wide field imaging will be a unique scientific capability for astronomy. Key benefits will be realized in planetary science, galactic, and extra-galactic astronomy. High angular resolution is essential to disentangle highly complex sources, particularly in star formation regions and external galaxies, and MegaMIR provides this performance over a full field of view. Because of the great impact being made by space observatories like the Spitzer Space Telescope, the number of available targets for study has greatly increased in recent years, and MegaMIR will allow efficient follow up science.

  18. The portable atmospheric research interferometric spectrometer for the infrared, PARIS-IR

    NASA Astrophysics Data System (ADS)

    Fu, Dejian; Walker, Kaley A.; Sung, Keeyoon; Boone, Chris D.; Soucy, Marc-Andre; Bernath, Peter F.

    2007-01-01

    A new compact, portable Fourier transform spectrometer, called the Portable Atmospheric Research Interferometric Spectrometer for the Infrared (PARIS-IR), has been built for atmospheric remote sensing. The first comprehensive description of the configuration and performance of this instrument for ground-based and balloon-borne operation is provided. Sample atmospheric absorption spectra and representative results observed at the Waterloo Atmospheric Observatory (WAO) are given. The good agreement between PARIS IR, Brewer spectrophotometer, and ozonesonde measurements of the column density of ozone at mid-latitudes demonstrate the performance and the reliability of the instrument.

  19. The Near Infrared robotic telescope REM

    NASA Astrophysics Data System (ADS)

    Goldoni, P.; Rem Team

    Observations of the prompt afterglow of Gamma Ray Burst events are unanimously considered of paramount importance for GRB science and related cosmology. Such observations at NIR wavelengths are even more promising allowing one to monitor high-z Ly-alfa absorbed bursts as well as events occurring in dusty star-forming regions. In these pages we present REM (Rapid Eye Mount), a fully robotized fast slewing telescope equipped with a high throughput NIR (Z, J, H, K) camera dedicated to detecting the prompt IR afterglow. REM can discover objects at extremely high redshift and trigger large telescopes to observe them. The REM telescope will simultaneously feed ROSS (REM Optical Slitless spectrograph) via a dichroic. ROSS will intensively monitor the prompt optical continuum of GRB afterglows. The synergy between REM-IR cam and ROSS makes REM a powerful observing tool for any kind of fast transient phenomena. The REM telescope is now installed in La Silla and its Science Verification Phase has been performed in Spring 2004. Preliminary results will be presented.

  20. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII)

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2012-01-01

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infrared interferometer to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer to simultaneously obtain spatial and spectral information on science targets; the long baseline provides subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. Here, we present key aspects of the overall design of the mission and provide an overview of the current status of the project. We also discuss briefly the implications of this experiment for future space-based far-infrared interferometers.

  1. History of infrared telescopes and astronomy

    NASA Astrophysics Data System (ADS)

    Rieke, G. H.

    2009-08-01

    The first attempts to measure the infrared outputs of stars preceded by nearly a century the permanent establishment of infrared astronomy as an important aspect of the field. There were a number of false starts in that century, significant efforts that had little impact on the astronomical community at large. Why did these efforts fizzle out? What was different in the start that did not fizzle, in the 1960s? I suggest that the most important advances were the success of radio astronomy in demonstrating interesting phenomena outside of the optical regime, and the establishment virtually simultaneously in the United States of a number of research groups that could support each other and compete against one another in their approach to infrared astronomy.

  2. Design of infrared diffractive telescope imaging optical systems

    NASA Astrophysics Data System (ADS)

    Zhang, ZhouFeng; Hu, BingLiang; Yin, QinYe; Xie, YongJun; Kang, FuZeng; Wang, YanJun

    2015-10-01

    Diffractive telescope is an updated imaging technology, it differs from conventional refractive and reflective imaging system, which is based on the principle of diffraction image. It has great potential for developing the larger aperture and lightweight telescope. However, one of the great challenges of design this optical system is that the diffractive optical element focuses on different wavelengths of light at different point in space, thereby distorting the color characteristics of image. In this paper, we designs a long-wavelength infrared diffractive telescope imaging system with flat surface Fresnel lens and cancels the infrared optical system chromatic aberration by another flat surface Fresnel lens, achieving broadband light(from 8μm-12μm) to a common focus with 4.6° field of view. At last, the diffuse spot size and MTF function provide diffractive-limited performance.

  3. BETTII: The Balloon Experimental Twin Telescope for Infrared Interferometry

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2011-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding the universe. The relatively low angular resolution of these missions, however, is insufficient to resolve the physical scale on which mid-to far-infrared emission arises. We will build the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII),8oeight-meter Michelson interferometer to fly on a high-altitude balloon. BETTII's spectral-spatial capability, provided by an instrument using double-Fourier techniques, will address key questions about the nature of disks io young star clusters and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the technological groundwork for future space interferometers.

  4. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII)

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.

    2010-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe. The relatively low angular resolution of these missions, however, is insufficient to resolve the physical scale on which mid-to far-infrared emission arises. We will build the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII), an eight-meter Michelson interferometer to fly on a high-altitude balloon. BETTII's spectral-spatial capability, provided by an instrument using double-Fourier techniques, will address key questions about the nature of disks in young star clusters and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the technological groundwork for future space interferometers.

  5. The EXIST Infra-Red Telescope System: Design and Performance

    NASA Technical Reports Server (NTRS)

    Moseley, Samuel H.

    2010-01-01

    The Infra-Red Telescope is a critical element of the EXIST (Energetic X-Ray Imaging Survey Telescope) observatory. It is a passively cooled 1.lm visible/infrared telescope. The primary goal of the IRT is to obtain photometric and spectroscopic measurements of high redshift (>6) gamma ray burst afterglows to study the nature of these enigmatic events and their environments, and to use them as probes of the composition and ionization state of the intergalactic medium of the young universe. The IRT will provide a prompt follow up (within three minutes) of the transient discovered by the EXIST with exceptional NIR sensitivity (AB=24 in 100s) surpassing HST in the infrared due to its passively cooled (- 30 C) mirror. Its optical design and spectral coverage is tailored to the high redshift transient events that require prompt pointing, identification, accurate photometry and both low and high resolution spectroscopy. Here we describe the telescope, its instrument complement, and the cooling systems which provide its remarkable sensitivity

  6. Infrared Testing of the Wide-field Infrared Survey Telescope Grism Using Computer Generated Holograms

    NASA Technical Reports Server (NTRS)

    Dominguez, Margaret Z.; Content, David A.; Gong, Qian; Griesmann, Ulf; Hagopian, John G.; Marx, Catherine T; Whipple, Arthur L.

    2017-01-01

    Infrared Computer Generated Holograms (CGHs) were designed, manufactured and used to measure the performance of the grism (grating prism) prototype which includes testing Diffractive Optical Elements (DOE). The grism in the Wide Field Infrared Survey Telescope (WFIRST) will allow the surveying of a large section of the sky to find bright galaxies.

  7. Viewing the Universe with Infrared Eyes: The Spitzer Space Telescope

    NASA Astrophysics Data System (ADS)

    Fazio, Giovanni G.; Spitzer Science Center

    2016-01-01

    The Spitzer Space Telescope, launched on 2003 August 25, continues to produce new and exciting views of the Universe as seen in infrared light. Spitzer is the fourth and final space telescope in NASA's Great Observatory series. Originally it consisted of a liquid-helium-cooled 85-cm telescope and three imaging and spectroscopic instruments capable of observing infrared light (3-160 micron wavelength) from regions of space invisible to optical telescopes. In mid-2009 Spitzer's cryogen was exhausted, leaving the observatory with two operating imaging arrays at 3.6 and 4.5 micron wavelength. "Warm" Spitzer, as it is now called, continues to match the sensitivity achieved at these wavelengths during the cryogenic mission and remains very much in demand. The Spitzer Space Telescope has changed our view of the Universe. Spitzer's scientific results include the study of the formation and evolution of galaxies in the early Universe, star formation and evolution, exoplanets, the structure and evolution of planetary disks around nearby stars, the cosmic distance scale, clusters of galaxies, near-Earth asteroids, and comets. After a brief description of the Spitzer mission, achievements of Spitzer's extragalactic and galactic observational programs will be presented, including many of Spitzer's very spectacular images.

  8. NIFTE: The Near Infrared Faint-Object Telescope Experiment

    NASA Technical Reports Server (NTRS)

    Bock, James J.; Lange, Andrew E.; Matsumoto, T.; Eisenhardt, Peter B.; Hacking, Perry B.; Schember, Helene R.

    1994-01-01

    The high sensitivity of large format InSb arrays can be used to obtain deep images of the sky at 3-5 micrometers. In this spectral range cool or highly redshifted objects (e.g. brown dwarfs and protogalaxies) which are not visible at shorter wavelengths may be observed. Sensitivity at these wavelengths in ground-based observations is severly limited by the thermal flux from the telescope and from the earth's atmosphere. The Near Infrared Faint-Object Telescope Experiment (NIFTE), a 50 cm cooled rocket-borne telescope combined with large format, high performance InSb arrays, can reach a limiting flux less than 1 micro-Jy(1-sigma) over a large field-of-view in a single flight. In comparison, the Infrared Space Observatory (ISO) will require days of observation to reach a sensitivity more than one order of magnitude worse over a similar area of the sky. The deep 3-5 micrometer images obtained by the rocket-borne telescope will assist in determining the nature of faint red objects detected by ground-based telescopes at 2 micrometers, and by ISO at wavelengths longer than 5 micrometers.

  9. Thermal design of a Shuttle infrared telescope facility /SIRTF/

    NASA Technical Reports Server (NTRS)

    Stoll, R.; Willen, S.

    1980-01-01

    A thermal design concept has been developed for a cryogenically-cooled infrared telescope facility which will be carried aboard the Space Shuttle for missions of 14 to 30 days. Supercitical helium at 6 K is the principal coolant. Auxiliary tanks of superfluid helium at 2 K are utilized to provide additional low-temperature cooling requirements of specific instruments. The preliminary thermal design described enables SIRTF to provide the low-temperature environment for the telescope and instruments, while maintaining thermally-induced optical degradations within acceptable limits with a cryogen utilization rate compatible with weight and volumetric constraints.

  10. Asteroid observations with the Hubble Space Telescope and the Space Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Zellner, B.; Wells, Eddie N.; Chapman, Clark R.; Cruikshank, D. P.

    1989-01-01

    The ways that the asteroids can be studied with the Hubble Space Telescope (HST) and the Space Infrared Telescope Facility (SIRTF) are examined. Spectrophotometry of asteroids and the study of asteroid surfaces, shape, spins, configuration, normal reflectance, and limb darkening of asteroids using the HST are addressed along with the detection of asteroid satellites and the discovery of small asteroids using the HST. The relation of the HST to its ground system is described, as are the spectrophotometric instruments of the HST. Imaging with the HST using the Faint Object Camera and the Wide Field and Planetary Camera is examined. Finally, the SIRTF observatory, instrumentation, and capabilities for solar system science are discussed.

  11. Designing the Balloon Experimental Twin Telescope for Infrared Interferometry

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2011-01-01

    While infrared astronomy has revolutionized our understanding of galaxies, stars, and planets, further progress on major questions is stymied by the inescapable fact that the spatial resolution of single-aperture telescopes degrades at long wavelengths. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter boom interferometer to operate in the FIR (30-90 micron) on a high altitude balloon. The long baseline will provide unprecedented angular resolution (approx. 5") in this band. In order for BETTII to be successful, the gondola must be designed carefully to provide a high level of stability with optics designed to send a collimated beam into the cryogenic instrument. We present results from the first 5 months of design effort for BETTII. Over this short period of time, we have made significant progress and are on track to complete the design of BETTII during this year.

  12. Thermal performance evaluation of the infrared telescope dewar subsystem

    NASA Technical Reports Server (NTRS)

    Urban, E. W.

    1986-01-01

    Thermal performance evaluations (TPE) were conducted with the superfluid helium dewar of the Infrared Telescope (IRT) experiment from November 1981 to August 1982. Test included measuring key operating parameters, simulating operations with an attached instrument cryostat and validating servicing, operating and safety procedures. Test activities and results are summarized. All objectives are satisfied except for those involving transfer of low pressure liquid helium (LHe) from a supply dewar into the dewar subsystem.

  13. Information processing for the infrared balloon telescope Goldener Drache

    NASA Astrophysics Data System (ADS)

    Haser, L.

    1983-02-01

    The information processing system of the ground station and balloon carrying an infrared telescope is described. The ground-balloon link is achieved by telemetry and the control by a computer. The operation scheme contains programs for planning, observations, decision aids during the flight, remote control, telemetry interpretation, and data registration. The real time data are presented partly via computer and partly via direct signal coding. All data can be stored on magnetic tape.

  14. Alignment and evaluation of the cryogenic corrected infrared astronomical satellite /IRAS/ telescope

    NASA Technical Reports Server (NTRS)

    Harned, N.; Harned, R.; Melugin, R.

    1980-01-01

    Room temperature alignment and evaluation techniques for the Infrared Astronomical Satellite (IRAS) telescope, which has a primary mirror figured to correct for surface distortions and the 2 K operating temperature are discussed. Interferometric cryogenic testing of the 0.6 m, f/1.5 lightweighted beryllium primary mirror at its intended operating temperature reveals surface distortions that can be modeled with Zernike polynomials. With this model, it becomes possible to derive the 'inverse' of the cryowavefront error (ideal cryo mirror) and to figure the cryo correction into the primary mirror using Perkin-Elmer's Computer Controlled Polisher. It is recognized that during room temperature assembly of the system, misalignment of the secondary mirror can introduce additional unwanted aberrations that may cancel or distort the wavefront errors purposely introduced by the cryo figuring. To avoid this possible degradation and to ensure optimum telescope performance, the system Zernike polynomial coefficients and wavefront maps generated from the in-process alignment interferograms are monitored and compared to Zernike coefficients and wavefront maps for the cryo corrected primary mirror.

  15. The Balloon Experimental Twin Telescope for Infrared Interferometry

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.

    2008-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe, and observations with Spitzer, the upcoming Herschel mission, and SOFIA will continue to provide exciting new discoveries. The relatively low angular resolution of these missions, however, is insufficient to resolve the physical scales on which mid- to far-infrared emission arises, resulting in source and structure ambiguities that limit our ability to answer key science questions. Interferometry enables high angular resolution at these wavelengths, a powerful tool for scientific discovery, We will build the Balloon Experimental Twin Telescope for Infrared Interferometry (BETII), an eight-meter baseline Michelson stellar interferometer to fly on a high-altitude balloon. BETTII's spectral-spatial capability, provided by an instrument using double-Fourier techniques, will address key questions about the nature of disks in young star clusters and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the technological groundwork for future space interferometers,

  16. Solar System Studies with the Space Infrared Telescope Facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.; DeVincenzi, Donald L. (Technical Monitor)

    1998-01-01

    SIRTF (Space Infrared Telescope Facility) is the final element in NASA's 'Great Observatories' program. It consists of an 85-cm cryogenically-cooled observatory for infrared astronomy from space. SIRTF is scheduled for launch in late 2001 or early 2002 on a Delta rocket into a heliocentric orbit trailing the Earth. Data from SIRTF will be processed and disseminated to the community through the SIRTF Science Center (SSC) located at the Infrared Processing and Analysis Center (IPAC) at Caltech. Some 80/% of the total observing time (estimated at a minimum of 7500 hours of integration time per year for the mission lifetime of about 4 years) will be available to the scientific community at large through a system of refereed proposals. Three basic instruments are located in the SIRTF focal plane. The Multiband Imaging Photometer (MIPS), the Infrared Array Camera (IRAC), and the Infrared Spectrometer (IRS), taken together, provide imaging and spectroscopy from 3.5 to 160 microns. Among the solar system studies suited to SIRTF are the following: 1) spectroscopy and radiometry of small bodies from the asteroid main belt, through the Trojan clouds, to the Kuiper Disk; 2) dust distribution in the zodiacal cloud and the Earth's heliocentric dust ring; 3) spectroscopy and radiometry of comets; and 4) spectroscopy and radiometry of planets and their satellites. Searches for, and studies of dust disks around other stars, brown dwarfs, and superplanets will also be conducted with SIRTF. The SORTIE web site (http://ssc.ipac.caltech.edu/sirtf) contains important details and documentation on the project, the spacecraft, the telescope, instruments, and observing procedures. A community-wide workshop for solar system studies with SIRTF is in the planning stages by the author and Martha S. Hanner for the summer of 1999.

  17. Hubble Space Telescope Fine Guidance Sensor Interferometric Parallaxes; How, Why, and What

    NASA Astrophysics Data System (ADS)

    Benedict, George Frederick; McArthur, Barbara E.

    2015-08-01

    Over the past sixteen years the Fine Guidance Sensors on Hubble Space Telescope have produced astrometric measures with which to derive over 60 high-precision absolute parallaxes. Targets included the usual suspects (Cepheids and RR Lyr stars) as well as planetary nebulae central stars, dwarf novae, members of the Pleiades and Hyades clusters, M dwarf binaries, and exoplanet host stars. We briefly outline our techniques and summarize our results with four graphs: a Cepheid Leavitt Law, an RR Lyr K-band Period-Luminosity relation, an M dwarf Mass-Luminosity relation, and an MK vs (J-K)0 HR diagram constructed entirely with Hubble Space Telescope parallaxes. The median parallax error for 64 objects was 0.2 milliseconds of arc, or 2.6%.The future of Hubble Space Telescope astrometry likely lies with WFC spatial scanning. The far future of space astrometry lies with Gaia.FGS astrometry succeeded thanks to contributions over the years from L. Abramowicz-Reed, A. Bradley, R. Duncombe, O. Franz, L. Fredrick, P. Hemenway, T. Harrison, T. Henry, W. Jefferys, E. Nelan, P. Shelus, D. Story, W. van Altena, L. Wasserman, and A. Whipple.

  18. Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets coronagraphic operations: lessons learned from the Hubble Space Telescope and the James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Debes, John H.; Ygouf, Marie; Choquet, Elodie; Hines, Dean C.; Perrin, Marshall D.; Golimowski, David A.; Lajoie, Charles-Phillipe; Mazoyer, Johan; Pueyo, Laurent; Soummer, Rémi; van der Marel, Roeland

    2016-01-01

    The coronagraphic instrument (CGI) currently proposed for the Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets (WFIRST-AFTA) mission will be the first example of a space-based coronagraph optimized for extremely high contrasts that are required for the direct imaging of exoplanets reflecting the light of their host star. While the design of this instrument is still in progress, this early stage of development is a particularly beneficial time to consider the operation of such an instrument. We review current or planned operations on the Hubble Space Telescope and the James Webb Space Telescope with a focus on which operational aspects will have relevance to the planned WFIRST-AFTA CGI. We identify five key aspects of operations that will require attention: (1) detector health and evolution, (2) wavefront control, (3) observing strategies/postprocessing, (4) astrometric precision/target acquisition, and (5) polarimetry. We make suggestions on a path forward for each of these items.

  19. Space Infrared Telescope Facility (SIRTF) design and thermal analysis

    NASA Technical Reports Server (NTRS)

    Lee, Jeffrey H.

    1987-01-01

    The design and performance characteristics of an observatory are compared with those of a storage dewar. The critical design technologies required to increase cryogen dewar lifetime are discussed. In particular, outer shell temperature, vapor cooled shields, multilayer insulation performance, and tank support systems are analyzed to assess their impact on cryogen lifetime for both the observatory and the storage dewar. The cryogen lifetime and cryogen mass loss rate of the Space Infrared Telescope Facility (SIRTF) are compared with that of the Infrared Astronomy Satellite and the Cosmic Background Explorer Satellite. A 0.1 percent mass loss per day of superfluid helium dewar can be designed using current state-of-the-art dewar technology. Space-based liquid hydrogen and liquid oxygen tanks can be designed for a 5-year lifetime.

  20. 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.

  1. A near-infrared interferometric survey of debris-disc stars. V. PIONIER search for variability

    NASA Astrophysics Data System (ADS)

    Ertel, S.; Defrère, D.; Absil, O.; Le Bouquin, J.-B.; Augereau, J.-C.; Berger, J.-P.; Blind, N.; Bonsor, A.; Lagrange, A.-M.; Lebreton, J.; Marion, L.; Milli, J.; Olofsson, J.

    2016-10-01

    Context. Extended circumstellar emission has been detected within a few 100 milli-arcsec around ≳10% of nearby main sequence stars using near-infrared interferometry. Follow-up observations using other techniques, should they yield similar results or non-detections, can provide strong constraints on the origin of the emission. They can also reveal the variability of the phenomenon. Aims: We aim to demonstrate the persistence of the phenomenon over the timescale of a few years and to search for variability of our previously detected excesses. Methods: Using Very Large Telescope Interferometer (VLTI)/Precision Integrated Optics Near Infrared ExpeRiment (PIONIER) in H band we have carried out multi-epoch observations of the stars for which a near-infrared excess was previously detected using the same observation technique and instrument. The detection rates and distribution of the excesses from our original survey and the follow-up observations are compared statistically. A search for variability of the excesses in our time series is carried out based on the level of the broadband excesses. Results: In 12 of 16 follow-up observations, an excess is re-detected with a significance of > 2σ, and in 7 of 16 follow-up observations significant excess (> 3σ) is re-detected. We statistically demonstrate with very high confidence that the phenomenon persists for the majority of the systems. We also present the first detection of potential variability in two sources. Conclusions: We conclude that the phenomenon responsible for the excesses persists over the timescale of a few years for the majority of the systems. However, we also find that variability intrinsic to a target can cause it to have no significant excess at the time of a specific observation. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program IDs 088.C-0266, 089.C-0365, 090.C-0526, 091.C-0576, 091.C-0597, 094.C-0232, and commissioning data.

  2. The Balloon Experimental Twin Telescope for Infrared Interferometry

    NASA Technical Reports Server (NTRS)

    Silverburg, Robert

    2009-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe, and observations with Spitzer, the upcoming Herschel mission, and SOFIA will continue to provide exciting new discoveries. The comparatively low spatial resolution of these missions, however, is insufficient to resolve the physical scales on which mid- to far-infrared emission arises, resulting in source and structure ambiguities that limit our ability to answer key science questions. Interferometry enables high angular resolution at these wavelengths. We have proposed a new high altitude balloon experiment, the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). High altitude operation makes far-infrared (30- 300micron) observations possible, and BETTII's 8-meter baseline provides unprecedented angular resolution (approx. 0.5 arcsec) in this band. BETTII will use a double-Fourier instrument to simultaneously obtain both spatial and spectral information. The spatially resolved spectroscopy provided by BETTII will address key questions about the nature of disks in young cluster stars and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the groundwork for future space interferometers.

  3. Shuttle infrared telescope facility pointing and control system

    NASA Technical Reports Server (NTRS)

    Lorell, K. R.; Barrows, W. F.; Matsumoto, Y. T.

    1981-01-01

    The Shuttle Infrared Telescope Facility (SIRTF) is being designed as a 0.85 m cryogenically cooled telescope capable of a three order of magnitude improvement over currently available infrared instruments. The SIRTF requires that the image at the focal plane be stabilized to better than 0.25 arcsec with an absolute accuracy of 1.0 arcsec. Current pointing-mount performance simulations indicate that neither of these requirements can be met without additional stabilization. The SIRTF pointing and control system will utilize gyro outputs, star field position measurements from a focal plane fine guidance sensor, and a steerable secondary mirror to provide the necessary stabilization and pointing control. The charge coupled device fine guidance sensor tracks multiple stars simultaneously and, through the use of multistar processing algorithms in a high performance microcomputer, generates three-axis attitude errors and gyro-drift estimates to correct the pointing-mount gyros. A high-bandwidth feedforward loop, driven directly from the pointing-mount gyro package, controls the steering mirror in order to correct disturbances not compensated for by the pointing-mount control system. A prototype design for the SIRTF pointing and control system is described in detail. Performance analyses made using a digital simulation of the pointing and control system as well as experimental data obtained in laboratory and field test measurements are presented.

  4. Wide-Field InfraRed Survey Telescope WFIRST

    NASA Technical Reports Server (NTRS)

    Green, J.; Schechter, P.; Baltay, C.; Bean, R.; Bennett, D.; Brown, R.; Conselice, C.; Donahue, M.; Fan, X.; Rauscher, B.; Rhodes, J.; Roellig, T.; Stern, D.; Gehrels, N.; Sambruna, R.; Traub, W.; Barry, R. K.; Content, D.; Goullioud, R.; Grady, K.; Kruk, J.; Melton, M.; Peddie, C.; Rioux, N.; Seiffert, M.

    2012-01-01

    In December 2010, NASA created a Science Definition Team (SDT) for WFIRST, the Wide Field Infra-Red Survey Telescope, recommended by the Astro 2010 Decadal Survey as the highest priority for a large space mission. The SDT was chartered to work with the WFIRST Project Office at GSFC and the Program Office at JPL to produce a Design Reference Mission (DRM) for WFIRST. Part of the original charge was to produce an interim design reference mission by mid-2011. That document was delivered to NASA and widely circulated within the astronomical community. In late 2011 the Astrophysics Division augmented its original charge, asking for two design reference missions. The first of these, DRM1, was to be a finalized version of the interim DRM, reducing overall mission costs where possible. The second of these, DRM2, was to identify and eliminate capabilities that overlapped with those of NASA's James Webb Space Telescope (henceforth JWST), ESA's Euclid mission, and the NSF's ground-based Large Synoptic Survey Telescope (henceforth LSST), and again to reduce overall mission cost, while staying faithful to NWNH. This report presents both DRM1 and DRM2.

  5. The NASA Infrared Telescope Facility (IRTF): New Observational Capabilities

    NASA Astrophysics Data System (ADS)

    Tokunaga, Alan T.; Bus, S. J.; Connelley, Michael S.; Rayner, John T.

    2015-11-01

    The NASA Infrared Telescope Facility (IRTF) is a 3.0-m infrared telescope located at an altitude of 4.2 km near the summit of Mauna Kea on the island of Hawaii. The IRTF was established by NASA to support planetary science missions. Current instruments include: (1) SpeX, a 0.7-5.3 μm moderate resolution spectrograph with a slit-viewing camera that is also an imager, (2) MORIS, a high-speed CCD imager attached to SpeX for simultaneous visible and near-infrared observations, and (3) CSHELL, a 1-5 μm high-resolution spectrograph. MORIS can also be used as a visible wavelength guider for SpeX. Detector upgrades have recently been made to SpeX. We discuss new observational capabilities resulting from completion of a new echelle spectrograph for 1-5 μm with resolving power of 70,000 with a 0.375 arcsec slit. This instrument will be commissioned starting in the spring of 2016. We also plan to restore to service our 8-25 μm camera, MIRSI. It will be upgraded with a closed-cycle cooler that will eliminate the need for liquid helium and allow continuous use of MIRSI on the telescope. This will enable thermal observations of NEOs on short notice. We also plan to upgrade MIRSI to have a simultaneous visible imager for guiding and for photometry. The IRTF supports remote observing from any site. This eliminates the need for travel to the observatory and short observing time slots can be supported. We also welcome onsite visiting astronomers. In the near future we plan to implement a low-order wave-front sensor to allow real-time focus and collimation of the telescope. This will greatly improve observational efficiency. For further information on the IRTF and its instruments including visitor instruments, see: http://irtfweb.ifa.hawaii.edu/. We gratefully acknowledge the support of NASA contract NNH14CK55B, NASA Science Mission Directorate.

  6. An Infrared Telescope for Planet Detection and General Astrophysics

    NASA Technical Reports Server (NTRS)

    Lillie, C. F.; Atkinson, C. B.; Casement, L. S.; Flannery, M. R.; Kroening, K. V.; Moses, S. L.

    2004-01-01

    NASA plans to launch a Terrestrial Planet Finder (TPF) mission in 2014 to detect and characterize Earth-like planets around nearby stars, perform comparative planetology studies, and obtain general astrophysics observations. During our recently completed a TPF Mission Architecture study for NASA/JPL we developed the conceptual design for a 28-meter telescope with an IR Coronagraph that meets these mission objectives. This telescope and the technology it embodies are directly applicable to future Far-IR and Submillimeter space missions. The detection of a 30th magnitude planet located within 50 milli-arc-seconds of a 5th (Visual) magnitude star is an exceptionally challenging objective. Observations in the thermal infrared (7-17 microns) are somewhat easier since the planet is "only" 15(sup m) fainter than the star at these wavelengths, but many severe challenges must still be overcome. These challenges include: 1. Designing a coronagraph for star:planet separations less than or equal to lambda/D. 2. Developing the deployment scheme for a 28m space telescope that can fit in an existing launch vehicle payload fairing. 3. Generating configuration layouts for the IR telescope, coronagraph, spacecraft bus, sunshade, solar array, and high-gain antenna. 4. Providing: Structural stability to within 10 microns to support the optics. Thermal control to achieve the necessary structural stability, as well as providing a stable (approx. 30K) thermal environment for the optics. Dynamics isolation from potential jitter sources. 5. Minimizing launch mass to provide the maximum payload for the science mission Interfacing to an EELV Heavy launch vehicle, including acoustic and stress loads for the launch environment. 6. Identifying the key technologies (which can be developed by 2009) that will enable TPF mission to be performed. 7. Generating a manufacturing plan that will permit TPF to be developed at a reasonable cost and schedule. Many of these design challenges result in

  7. Solar System Observing with the Space Infrared Telescope Facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Cleve, J. Van; Meadows, V. S.; Stansberry, J.

    2003-01-01

    SIRTF is NASA's Space Infrared Telescope Facility. Currently planned for launch on 15 Apr 2003, it is the final element in NASA's Great Observatories Program. SIRTF has an 85 cm diameter f/12 lightweight beryllium telescope, cooled to lekss than 5.5K. It is diffraction-limited at 6.5 microns, and has wavelengthcoverage from 3-180 microns. Its estimated lifetime (limited by cryogen) is 2.5 years at minimum, with a goal of 5+ years. SIRTF has three instruments, IRAC, IRS, and MIPS. IRAC (InfraRed Array Camera) provides simultaneous images at wavelengths of 3.6, 4.5, 5.8, and 8.0 microns. IRS (InfraRed Spectrograph) has 4 modules providing low-resolution (R=60-120) spectra from 5.3 to 40 microns, high-resolution (R=600) spectra from 10 to 37 microns, and an autonomous target acquisition system (PeakUp) which includes small-field imaging at 15 microns. MIPS (Multiband Imaging Photometer for SIRTF)} does imaging photometry at 24, 70, and 160 m and low-resolution (R=15-25) spectroscopy (SED) between 55 and 96 microns. The SIRTF Guaranteed Time Observers (GTOs) are planning to observe Outer Solar System satellites and planets, extinct comets and low-albedo asteroids, Centaurs and Kuiper Belt Objects, cometary dust trails, and a few active short-period comets. The GTO programs are listed in detail in the SIRTF Reserved Observations Catalog (ROC). We would like to emphasize that there remain many interesting subjects for the General Observers (GO). Proposal success for the planetary observer community in the first SIRTF GO proposal cycle (GO-1) determines expectations for future GO calls and Solar System use of SIRTF, so we would like promote a strong set of planetary GO-1 proposals. Towards that end, we present this poster, and we will convene a Solar System GO workshop 3.5 months after launch.

  8. Wide-Field Infrared Survey Telescope (WFIRST) Interim Report

    NASA Technical Reports Server (NTRS)

    Green, J.; Schechter, P.; Baltay, C.; Bean, R.; Bennett, D.; Brown, R.; Conselice, C.; Donahue, M.; Gaudi, S.; Lauer, T.; Perlmutter, S.; Rauscher, B.; Rhodes, J.; Roellig, T.; Stern, D.; Sumi, T.; Gerhels, N.; Sambruna, R.; Barry, R. K.; Content, D.; Grady, K; Jackson, C.; Kruk, J.; Melton, M.; Rioux, N.

    2011-01-01

    The New Worlds, New Horizons (NWNH) in Astronomy and Astrophysics 2010 Decadal Survey prioritized the community consensus for ground-based and space-based observatories. Recognizing that many of the community s key questions could be answered with a wide-field infrared survey telescope in space, and that the decade would be one of budget austerity, WFIRST was top ranked in the large space mission category. In addition to the powerful new science that could be accomplished with a wide-field infrared telescope, the WFIRST mission was determined to be both technologically ready and only a small fraction of the cost of previous flagship missions, such as HST or JWST. In response to the top ranking by the community, NASA formed the WFIRST Science Definition Team (SDT) and Project Office. The SDT was charged with fleshing out the NWNH scientific requirements to a greater level of detail. NWNH evaluated the risk and cost of the JDEM-Omega mission design, as submitted by NASA, and stated that it should serve as the basis for the WFIRST mission. The SDT and Project Office were charged with developing a mission optimized for achieving the science goals laid out by the NWNH re-port. The SDT and Project Office opted to use the JDEM-Omega hardware configuration as an initial start-ing point for the hardware implementation. JDEM-Omega and WFIRST both have an infrared imager with a filter wheel, as well as counter-dispersed moderate resolution spectrometers. The primary advantage of space observations is being above the Earth's atmosphere, which absorbs, scatters, warps and emits light. Observing from above the atmosphere enables WFIRST to obtain precision infrared measurements of the shapes of galaxies for weak lensing, infrared light-curves of supernovae and exoplanet microlensing events with low systematic errors, and infrared measurements of the H hydrogen line to be cleanly detected in the 1

  9. Interferometric apodization of telescope apertures. I. First laboratory results obtained using a Mach-Zehnder interferometer

    NASA Astrophysics Data System (ADS)

    Carlotti, A.; Ricort, G.; Aime, C.; El Azhari, Y.; Soummer, R.

    2008-01-01

    Aims:We seek to produce apodized apertures for application in stellar coronagraphy to help in direct detections of exoplanets. We show that chromatic apodized apertures of any shape in transmission can be obtained with a specific MZI and we demonstrate this capability in two cases. Methods: The method takes advantage of the capabilities of the MZI, in which the two outputs correspond to the addition and subtraction of the two wave amplitudes in both arms. The result is obtained by re-imaging the entrance aperture of the telescope in the arms of the MZI where two complementary phase masks ± \\varphi (x,y) are set. At the two outputs of the MZI, the re-imaged apertures interfere, and their transmissions are multiplied respectively by a factor of the form cos[\\varphi(x,y)] and i sin[\\varphi(x,y)]. They correspond to the apodized and anti-apodized complementary outputs. Results: We present the results obtained for two types of apodization. A 1D cosine apodization for a square aperture is obtained by introducing a thin wedge-shaped air film, slightly tilting one of the mirrors of the MZI. A 2D circular symmetric apodization of the form cos[x2+y2] is obtained for a circular aperture using two complementary convergent and divergent lenses as phase masks. Aperture transmissions (in intensity) and corresponding point spread functions (PSFs) are given in each case and compared to the theoretical expectations. Conclusions: We have demonstrated the capability of the MZI to produce an apodized aperture. This result is obtained with no loss of photons, considering the fact that there are two complementary outputs. Considerations are given on the wavelength dependence of this technique.

  10. The NASA Infrared Telescope Facility (IRTF): Future Instrumentation and Upgrades

    NASA Astrophysics Data System (ADS)

    Tokunaga, Alan T.; Bus, S. J.; Connelley, Michael S.; Rayner, John T.

    2014-11-01

    The NASA Infrared Telescope Facility (IRTF) is a 3.0-m infrared telescope located at an altitude of 4.2 km near the summit of Mauna Kea on the island of Hawaii. The IRTF was established by NASA to obtain solar system observations of interest to NASA. The funding for IRTF operations was renewed in May 2014 for another 5 years. We discuss new instrumentation and upgrades during this time period. Current instruments include: (1) SpeX, a 0.7-5 μm moderate-resolution spectrograph and camera, (2) MORIS, a high-speed CCD imager attached to SpeX for simultaneous visible and near-infrared observations, and (3) CSHELL, a 1-5 μm high-resolution spectrograph. Detector upgrades have recently been made to SpeX. We are also designing and constructing a new echelle spectrograph for 1-5 μm. This instrument will be commissioned starting in early 2016. We also plan to restore to service our 8-25 μm camera, MIRSI. Our 1-5 μm camera, NSFCAM, was lost due to a failure of the liquid nitrogen can that was caused by an ice plug. We can restore this instrument to service but no plans have been made yet. The IRTF supports remote observing from any site. This eliminates the need for travel to the observatory and short observing time slots can be supported. We also welcome onsite visiting astronomers. In the near future we plan to implement a low-order wave-front sensor to allow real-time focus and collimation of the telescope. This will greatly improve observational efficiency. In the longer term, we envision the construction of an adaptive optics system that is optimized for solar system observations. This instrument would use the restored NSFCAM, which has a circular variable filter allowing selection of any wavelength from 1-5 μm. We welcome input for planetary science cases needing diffraction-limited imaging at 1-5 μm. For further information on the IRTF and its instruments including visitor instruments, see: http://irtfweb.ifa.hawaii.edu/. We gratefully acknowledge the support of

  11. Far-Infrared Line Mapper (FILM) on the Infrared Telescope in Space

    NASA Astrophysics Data System (ADS)

    Shibai, Hiroshi; Yui, Masao; Matsuhara, Hideo; Hiromoto, Norihisa; Nakagawa, Takao; Okuda, Haruyuki

    1994-06-01

    We have developed a Far-Infrared Line Mapper (FILM) as one of the four focal plane instruments on the Infrared Telescope in Space (IRTS). The FILM is a grating spectrometer designed to simultaneously measure (C II) 158 microns and (O I) 63 microns line intensities and continuum emission near the (C II) line with spatial resolution of 8 arcmin. Very high sensitivity and accuracy are achieved by using stressed and unstressed Ge: Ga detectors at 1.8 K with a helium cooled telescope and by using a spectral scanner to distinguish the line emission from the continuum emission. Line intensities of the (C II) and the (O I) will be mapped over 10% of the sky with much higher sensitivity than the previous survey measurements.

  12. Space infrared telescope pointing control system. Infrared telescope tracking in the presence of target motion

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Schneider, J. B.

    1986-01-01

    The use of charge-coupled-devices, or CCD's, has been documented by a number of sources as an effective means of providing a measurement of spacecraft attitude with respect to the stars. A method exists of defocussing and interpolation of the resulting shape of a star image over a small subsection of a large CCD array. This yields an increase in the accuracy of the device by better than an order of magnitude over the case when the star image is focussed upon a single CCD pixel. This research examines the effect that image motion has upon the overall precision of this star sensor when applied to an orbiting infrared observatory. While CCD's collect energy within the visible spectrum of light, the targets of scientific interest may well have no appreciable visible emissions. Image motion has the effect of smearing the image of the star in the direction of motion during a particular sampling interval. The presence of image motion is incorporated into a Kalman filter for the system, and it is shown that the addition of a gyro command term is adequate to compensate for the effect of image motion in the measurement. The updated gyro model is included in this analysis, but has natural frequencies faster than the projected star tracker sample rate for dim stars. The system state equations are reduced by modelling gyro drift as a white noise process. There exists a tradeoff in selected star tracker sample time between the CCD, which has improved noise characteristics as sample time increases, and the gyro, which will potentially drift further between long attitude updates. A sample time which minimizes pointing estimation error exists for the random drift gyro model as well as for a random walk gyro model.

  13. Emergency relief venting of the infrared telescope liquid helium dewar

    NASA Technical Reports Server (NTRS)

    Urban, E. W.

    1980-01-01

    An analysis is made of the emergency relief venting of the liquid helium dewar of the Spacelab 2 infrared telescope experiment in the event of a massive failure of the dewar guard vacuum. Such a failure, resulting from a major accident, could cause rapid heating and pressurization of the liquid helium in the dewar and lead to relief venting through the emergency relief system. The heat input from an accident is estimated for various fluid conditions in the dewar and the relief process as it takes place through one or both of the emergency relief paths is considered. It is shown that under all reasonable circumstances the dewar will safely relieve itself, and the pressure will not exceed 85 percent of the proof pressure or 63 percent of the burst pressure.

  14. Long life feasibility study for the shuttle infrared telescope facility

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A study was conducted to assess the feasibility of designing an Infrared Telescope of the 1 meter class which would operate effectively as a Shuttleborne, 14-day Spacelab payload and then be adapted with little modification to work as a 6 month Space station or free flyer payload. The optics configuration and requirements from a previous study were used without modification. In addition, an enhancement to 2 year mission lengths was studied. The cryogenic system selected was a hybrid design with an internal solid Hydrogen tank at 8 Kelvin and an internal superfluid tank at 2K. In addition to the cryogenic design, a detailed look at secondary mirror actuators for chopping, focus and decenter was conducted and analysis and cryo test reported.

  15. An Airborne Infrared Telescope and Spectrograph for Solar Eclipse Observations

    NASA Astrophysics Data System (ADS)

    DeLuca, Edward E.; Cheimets, Peter; Golub, Leon

    2014-06-01

    The solar infrared spectrum offers great possibilities for direct spatially resolved measurements of the solar coronal magnetic fields, via imaging of the plasma that is constrained to follow the magnetic field direction and via spectro-polarimetry that permits measurement of the field strength in the corona. Energy stored in coronal magnetic fields is released in flares and coronal mass ejections (CME) and provides the ultimate source of energy for space weather. The large scale structure of the coronal field, and the opening up of the field in a transition zone between the closed and open corona determines the speed and structure of the solar wind, providing the background environment through which CMEs propagate. At present our only direct measurements of the solar magnetic fields are in the photosphere and chromosphere. The ability to determine where and why the corona transitions from closed to open, combined with measurements of the field strength via infrared coronal spectro-polarimetry will give us a powerful new tool in our quest to develop the next generation of forecasting models.We describe a first step in achieving this goal: a proposal for a new IR telescope, image stabilization system, and spectrometer, for the NCAR HIPER GV aircraft. The telescope/spectrograph will operate in the 2-6micron wavelength region, during solar eclipses, starting with the trans-north American eclipse in August 2017. The HIAPER aircraft flying at ~35,000 ft will provide an excellent platform for IR observations. Our imaging and spectroscopy experiment will show the distribution and intensity of IR forbidden lines in the solar corona.

  16. Surveying the Inner Solar System with an Infrared Space Telescope

    NASA Astrophysics Data System (ADS)

    Buie, Marc W.; Reitsema, Harold J.; Linfield, Roger P.

    2016-11-01

    We present an analysis of surveying the inner solar system for objects that may pose some threat to Earth. Most of the analysis is based on understanding the capability provided by Sentinel, a concept for an infrared space-based telescope placed in a heliocentric orbit near the distance of Venus. From this analysis, we show that (1) the size range being targeted can affect the survey design, (2) the orbit distribution of the target sample can affect the survey design, (3) minimum observational arc length during the survey is an important metric of survey performance, and (4) surveys must consider objects as small as D=15{--}30 m to meet the goal of identifying objects that have the potential to cause damage on Earth in the next 100 yr. Sentinel will be able to find 50% of all impactors larger than 40 m in a 6.5 yr survey. The Sentinel mission concept is shown to be as effective as any survey in finding objects bigger than D = 140 m but is more effective when applied to finding smaller objects on Earth-impacting orbits. Sentinel is also more effective at finding objects of interest for human exploration that benefit from lower propulsion requirements. To explore the interaction between space and ground search programs, we also study a case where Sentinel is combined with the Large Synoptic Survey Telescope (LSST) and show the benefit of placing a space-based observatory in an orbit that reduces the overlap in search regions with a ground-based telescope. In this case, Sentinel+LSST can find more than 70% of the impactors larger than 40 m assuming a 6.5 yr lifetime for Sentinel and 10 yr for LSST.

  17. Instrument for Achieving High Angular Resolution on the Infrared Telescope

    NASA Technical Reports Server (NTRS)

    Hall, Donald N. B.

    1998-01-01

    Aberrations in stellar images caused by the atmosphere sets a significant limit on angular resolution in ground based astronomy. The largest of these aberrations is the image motion or wavefront tilt. Since the image motion is random it causes a blurring of the image, and this causes a blurring of the image from 0.3 arcseconds to about 0.7 arcseconds. The purpose of the tip-tilt project was to devise a system for the NASA Infrared Telescope Facility that would measure the image movement and correct it by rapidly tilting a mirror in two axes (tip and tilt). The system would involve building a CCD sensor package to measure the image motion, a new top end for the telescope to hold the tip-tilt mirror, a control system, and software. The system was designed to correct images for the facility camera, NSFCAM, and for the facility spectrometer, SPEX. Both of these instruments are equipped with a cold beamsplitter to feed the sensor package.

  18. The Infrared-Optical Telescope (IRT) of the Exist Observatory

    NASA Technical Reports Server (NTRS)

    Kutyrev, Alexander; Bloom, Joshua; Gehrels, Neil; Golisano, Craig; Gong, Quan; Grindlay, Jonathan; Moseley, Samuel; Woodgate, Bruce

    2010-01-01

    The IRT is a 1.1m visible and infrared passively cooled telescope, which can locate, identify and obtain spectra of GRB afterglows at redshifts up to z 20. It will also acquire optical-IR, imaging and spectroscopy of AGN and transients discovered by the EXIST (The Energetic X-ray Imaging Survey Telescope). The IRT imaging and spectroscopic capabilities cover a broad spectral range from 0.32.2m in four bands. The identical fields of view in the four instrument bands are each split in three subfields: imaging, objective prism slitless for the field and objective prism single object slit low resolution spectroscopy, and high resolution long slit on single object. This allows the instrument, to do simultaneous broadband photometry or spectroscopy of the same object over the full spectral range, thus greatly improving the efficiency of the observatory and its detection limits. A prompt follow up (within three minutes) of the transient discovered by the EXIST makes IRT a unique tool for detection and study of these events, which is particularly valuable at wavelengths unavailable to the ground based observatories.

  19. THE INFRARED TELESCOPE FACILITY (IRTF) SPECTRAL LIBRARY: COOL STARS

    SciTech Connect

    Rayner, John T.; Cushing, Michael C.; Vacca, William D. E-mail: michael.cushing@gmail.com

    2009-12-01

    We present a 0.8-5 {mu}m spectral library of 210 cool stars observed at a resolving power of R {identical_to} {lambda}/{delta}{lambda} {approx} 2000 with the medium-resolution infrared spectrograph, SpeX, at the 3.0 m NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. The stars have well-established MK spectral classifications and are mostly restricted to near-solar metallicities. The sample not only contains the F, G, K, and M spectral types with luminosity classes between I and V, but also includes some AGB, carbon, and S stars. In contrast to some other spectral libraries, the continuum shape of the spectra is measured and preserved in the data reduction process. The spectra are absolutely flux calibrated using the Two Micron All Sky Survey photometry. Potential uses of the library include studying the physics of cool stars, classifying and studying embedded young clusters and optically obscured regions of the Galaxy, evolutionary population synthesis to study unresolved stellar populations in optically obscured regions of galaxies and synthetic photometry. The library is available in digital form from the IRTF Web site.

  20. Quantitative Measurements of Daytime Near Infrared Sky Brightness at the AEOS 3.6 m Telescope

    DTIC Science & Technology

    2014-09-01

    Quantitative measurements of daytime near infrared sky brightness at the AEOS 3.6 m telescope Michael Hart, Stuart Jefferies Douglas Hope, James...HI 96753 ABSTRACT We report daytime sky brightness measurements recorded in the near infrared from the 3.6 m AEOS telescope . Measurements were made...techniques for high-resolution imaging of satellites from the AEOS telescope . 1 MOTIVATION At first glance it would appear that imaging in the near

  1. James Webb Telescope's Near Infrared Camera: Making Models, Building Understanding

    NASA Astrophysics Data System (ADS)

    Lebofsky, Larry A.; McCarthy, D. W.; Higgins, M. L.; Lebofsky, N. R.

    2010-10-01

    The Astronomy Camp for Girl Scout Leaders is a science education program sponsored by NASA's next large space telescope: The James Webb Space Telescope (JWST). The E/PO team for JWST's Near Infrared Camera (NIRCam), in collaboration with the Sahuaro Girl Scout Council, has developed a long-term relationship with adult leaders from all GSUSA Councils that directly benefits troops of all ages, not only in general science education but also specifically in the astronomical and technology concepts relating to JWST. We have been training and equipping these leaders so they can in turn teach young women essential concepts in astronomy, i.e., the night sky environment. We model what astronomers do by engaging trainers in the process of scientific inquiry, and we equip them to host troop-level astronomy-related activities. It is GSUSA's goal to foster girls’ interest and creativity in Science, Technology, Engineering, and Math, creating an environment that encourages their interests early in their lives while creating a safe place for girls to try and fail, and then try again and succeed. To date, we have trained over 158 leaders in 13 camps. These leaders have come from 24 states, DC, Guam, and Japan. While many of the camp activities are related to the "First Light” theme, many of the background activities relate to two of the other JWST and NIRCam themes: "Birth of Stars and Protoplanetary Systems” and "Planetary Systems and the Origin of Life.” The latter includes our own Solar System. Our poster will highlight the Planetary Systems theme: 1. Earth and Moon: Day and Night; Rotation and Revolution. 2. Earth/Moon Comparisons. 3. Size Model: The Diameters of the Planets. 4. Macramé Planetary (Solar) Distance Model. 5.What is a Planet? 6. Planet Sorting Cards. 7. Human Orrery 8. Lookback Time in Our Daily Lives NIRCam E/PO website: http://zeus.as.arizona.edu/ dmccarthy/GSUSA

  2. The NASA Infrared Telescope Facility: Instrument Upgrades and Plans

    NASA Astrophysics Data System (ADS)

    Tokunaga, Alan T.; Bus, S. J.; Connelley, M. S.; Rayner, J. T.

    2013-10-01

    The NASA Infrared Telescope Facility (IRTF) is a dedicated planetary 3-m telescope located at the summit of Mauna Kea. We discuss detector upgrades for our facility instruments, new instrument capabilities, and image quality upgrades. Detector upgrades are planned for SpeX during semester 2014A. We are also designing and constructing a new echelle spectrograph for 1-5 μm, to be commissioned starting in 2015. In terms of future capabilities, we would like input for planetary science cases needing diffraction-limited imaging at 1-5 μm and fast follow up of discoveries from sky surveys. Current instruments include: (1) SpeX, a 1-5 μm moderate-resolution spectrograph and camera, (2) MORIS, a high-speed CCD imager attached to SpeX for simultaneous visible and near-IR observations, (3) CSHELL, a 1-5 μm high-resolution spectrograph, and (4) NSFCAM, a 1-5 micron camera. MIRSI, an 8-25 μm camera, will be available after an upgrade to the array control electronics. Information on these instruments and also visitor instruments are given at: http://irtfweb.ifa.hawaii.edu/Facility/. The IRTF supports remote observing from any site. This eliminates the need for travel to the observatory, and therefore short observing time slots can be supported. We also welcome on-site visiting astronomers. For further information see: http://irtfweb.ifa.hawaii.edu/. We gratefully acknowledge the support of Cooperative Agreement no. NNX13AG88A with the NASA Science Mission Directorate, Planetary Astronomy Program.

  3. Development of Infrared Phase Closure Capability in the Infrared-Optical Telescope Array (IOTA)

    NASA Technical Reports Server (NTRS)

    Traub, Wesley A.

    2002-01-01

    We completed all major fabrication and testing for the third telescope and phase-closure operation at the Infrared-Optical Telescope Array (IOTA) during this period. In particular we successfully tested the phase-closure operation, using a laboratory light source illuminating the full delay-line optical paths, and using an integrated-optic beam combiner coupled to our Picnic-detector camera. This demonstration is an important and near-final milestone achievement. As of this writing, however, several tasks yet remain, owing to development snags and weather, so the final proof of success, phase-closure observation of a star, is now expected to occur in early 2002, soon after this report has been submitted.

  4. GMTNIRS (Giant Magellan Telescope near-infrared spectrograph): design concept

    NASA Astrophysics Data System (ADS)

    Lee, Sungho; Yuk, In-Soo; Lee, Hanshin; Wang, Weisong; Park, Chan; Park, Kwi-Jong; Chun, Moo-Young; Pak, Soojong; Strubhar, Joseph; Deen, Casey; Gully-Santiago, Michael; Rand, Jared; Seo, Haingja; Kwon, Jungmi; Oh, Heeyoung; Barnes, Stuart; Lacy, John; Goertz, John; Park, Won-Kee; Pyo, Tae-Soo; Jaffe, Daniel T.

    2010-07-01

    We are designing a sensitive high resolution (R=60,000-100,000) spectrograph for the Giant Magellan Telescope (GMTNIRS, the GMT Near-Infrared Spectrograph). Using large-format IR arrays and silicon immersion gratings, this instrument will cover all of the J (longer than 1.1 μm), H, and K atmospheric windows or all of the L and M windows in a single exposure. GMTNIRS makes use of the GMT adaptive optics system for all bands. The small slits will offer the possibility of spatially resolved spectroscopy as well as superior sensitivity and wavelength coverage. The GMTNIRS team is composed of scientists and engineers at the University of Texas, the Korea Astronomy and Space Science Institute, and Kyung Hee University. In this paper, we describe the optical and mechanical design of the instrument. The principal innovative feature of the design is the use of silicon immersion gratings which are now being produced by our team with sufficient quality to permit designs with high resolving power and broad instantaneous wavelength coverage across the near-IR.

  5. The Far-Infrared Photometer on the Infrared Telescope in Space

    NASA Technical Reports Server (NTRS)

    Lange, A. E.; Freund, M. M.; Sato, S.; Hirao, T.; Matsumoto, T.; Watabe, T.

    1994-01-01

    We describe the design and calibration of the Far-Infrared Photometer (FIRP), one of four focal plane instruments on the Infrared Telescope in Space (IRTS). The FIRP will provide absolute photometry in four bands centered at 150, 250, 400, and 700 microns with spectral resolution wavelength/wavelength spread is approximately 3 and spatial resolution delta theta = 0.5 degrees. High sensitivity is achieved by using bolometric detectors operated at 300 mK in an AC bridge circuit. The closed-cycle He-3 refrigerator can be recycled in orbit. A 2 K shutter provides a zero reference for each field of view. More than 10% of the sky will be surveyed during the 3 week mission lifetime with a sensitivity of less than 10(exp -13) W per sq cm per sr per 0.5 degree pixel.

  6. A Far Infrared Photometer (FIRP) for the infrared telescope in space (IRTS)

    NASA Technical Reports Server (NTRS)

    Freund, M. M.; Hirao, T.; Matsumoto, T.; Sato, S.; Watabe, T.; Brubaker, G. K.; Duband, L.; Grossman, B.; Larkin, N.; Lumetta, S.

    1993-01-01

    We describe the design and calibration of the Far-Infrared Photometer (FIRP), one of four focal plane instruments on the Infrared Telescope in Space (IRTS). The FIRP will provide absolute photometry in four bands centered at 150, 250, 400, and 700 micrometers with spectral resolution lambda/(Delta lambda) approx. = 3 and spatial resolution Delta theta = 0.5 degrees. High sensitivity is achieved by using bolometric detectors operated at 300 mK in an AC bridge circuit. The closed-cycle He-3 refrigerator can be recycled in orbit. A 2 K shutter provides a zero reference for each field of view. More than 10% of the sky will be surveyed during the approximately 3 week mission lifetime with a sensitivity of less than 10(exp -13) W/((sq cm)(sr)) per 0.5 degree pixel.

  7. Mexican Infrared-Optical New Technology Telescope: The TIM project

    NASA Astrophysics Data System (ADS)

    Salas, L.

    1998-11-01

    The scientific goals for TIM are an image quality of 0.25", consistent with the seeing at our site, optimization for the infrared as many scientific programs are going in that region of the spectrum, a M1 diameter in excess of 6.5 meters and a field of view limited to 10 arc minutes. Practical reasons, such as the limited funding available and the requirement of mexican financial agencies that the telescope should be built and installed in Mexico, lead us to decide for a segmented telescope, with a single secondary mirror, a single cassegrain focus and a light high stifness tubular structure. ALthough we are still working on the conceptual design of the telescope, there are some concepts that we are pursuing. The optical desing (M1+M2) is Ritchey-Cretien type with an hyperbolic primary 7.8 m od F/1.5 and a 0.9 m diameter f/15 secondary mirror. This will give a plate scale of 1.7 "/mm. This is 0.03 "/pix in direct mode, enough for AO goals. As for direct imaging, a factor of 5 reduction with 20 cm diam optical components would be able to produce 5' fields on a 2048, 20 microns type detector with 0.17"/pix. This implies that, with the use of auxiliary optics which is a common need for each particular instrument anyway, a wide variety of needs can be accomodated with a single secondary mirror. Choping for infrared observations would however introduce a additional cost in the secondary mirror. Alternatively the use of cold tertiary choping mirror is currently under study. The M1+M2 design currently aquires d80 of 0.17" in a 5' field without correction and 1" in a 10' field, that would require a field correcting lens. The M1 mirror will be segmented into 19 1.8 m diameter segments. There are 4 kinds of segments, the central, which we have kept to provide a reference for phasing, 6 more segments for the first ring and 12 in the outer ring, of two different kinds. The spacing between the segments is 5 mm, enough to reduce the inter-segment thermal background to half a

  8. The Space Infrared Interferometric Telescope (SPIRIT): Recent Study Results and Plans

    NASA Astrophysics Data System (ADS)

    Leisawitz, David; SPIRIT Mission Study Team

    2007-12-01

    SPIRIT was recommended in the 2002 "Community Plan for Far-IR/Submillimeter Space Astronomy.” A structurally connected interferometer, SPIRIT provides sensitive sub-arcsecond angular resolution images and integral field spectroscopy in the 25 to 400 micron wavelength range. SPIRIT was designed to revolutionize our understanding of planetary system formation, reveal otherwise-undetectable planets through the disk perturbations they induce, spectroscopically probe the atmospheres of extrasolar giant planets in orbits typical of most of the planets in our solar system, and yield significant new insight into the processes associated with galaxy formation and development. This paper updates previously presented study results and describes future study plans. Our SPIRIT mission concept study proposal was peer reviewed and selected by NASA for support under the Origins Probe Mission Concept Study program. NASA's Goddard Space Flight Center and four industry partners - Ball Aerospace, Boeing, Lockheed-Martin, and Northrop-Grumman - contributed generously the study. The Origins Probe study results were reviewed by an Advisory Review Panel.

  9. Coaxial Dual-wavelength Interferometric Method for a Thermal Infrared Focal-plane-array with Integrated Gratings

    NASA Astrophysics Data System (ADS)

    Shang, Yuanfang; Ye, Xiongying; Cao, Liangcai; Song, Pengfei; Feng, Jinyang

    2016-05-01

    Uncooled infrared (IR) focal-plane-array (FPA) with both large sensing range and high sensitivity is a great challenge due to the limited dynamic range of the detected signals. A coaxial dual-wavelength interferometric system was proposed here to detect thermal-induced displacements of an ultrasensitive FPA based on polyvinyl-chloride(PVC)/gold bimorph cantilevers and carbon nanotube (CNT)-based IR absorbing films. By alternately selecting the two displacement measurements performed by λ1 (=640 nm) and λ2 (=660 nm), the temperature measuring range with greater than 50% maximum sensitivity can be extended by eight-fold in comparison with the traditional single-wavelength mode. Meanwhile, the relative measurement error over the full measuring range is below 0.4%. In addition, it offers a feasible approach for on-line and on-wafer FPA characterization with great convenience and high efficiency.

  10. Reflectance-mode interferometric near-infrared spectroscopy quantifies brain absorption, scattering, and blood flow index in vivo.

    PubMed

    Borycki, Dawid; Kholiqov, Oybek; Srinivasan, Vivek J

    2017-02-01

    Interferometric near-infrared spectroscopy (iNIRS) is a new technique that measures time-of-flight- (TOF-) resolved autocorrelations in turbid media, enabling simultaneous estimation of optical and dynamical properties. Here, we demonstrate reflectance-mode iNIRS for noninvasive monitoring of a mouse brain in vivo. A method for more precise quantification with less static interference from superficial layers, based on separating static and dynamic components of the optical field autocorrelation, is presented. Absolute values of absorption, reduced scattering, and blood flow index (BFI) are measured, and changes in BFI and absorption are monitored during a hypercapnic challenge. Absorption changes from TOF-resolved iNIRS agree with absorption changes from continuous wave NIRS analysis, based on TOF-integrated light intensity changes, an effective path length, and the modified Beer-Lambert Law. Thus, iNIRS is a promising approach for quantitative and noninvasive monitoring of perfusion and optical properties in vivo.

  11. Application of a white-light interferometric measuring system as co-phasing the segmented primary mirrors of the high-aperture telescope

    NASA Astrophysics Data System (ADS)

    Song, Helun; Li, Huaqiang; Xian, Hao; Huang, Jian; Wang, Shengqian; Jiang, Wenhan

    2008-03-01

    For the optical system of the telescope, with the increase in telescope size, the manufacture of monolithic primary becomes increasingly difficult. Instead, the use of segmented mirrors, where many individual mirrors (the segments) work together to provide an image quality and an aperture equivalent to that of a large monolithic mirror, is considered a more appropriate strategy. But with the introduction of the large telescope mirror comprised of many individual segments, the problem of insuring a smooth continuous mirror surface (co-phased mirrors) becomes critical. One of the main problems is the measurement of the vertical displacement between the individual segments (piston error), for such mirrors, the segment vertical misalignment (piston error) between the segments must be reduced to a small fraction of the wavelength (<100nm) of the incoming light. The measurements become especially complicated when the piston error is in order of wavelength fractions. To meet the performance capabilities, a novel method for phasing the segmented mirrors optics system is described. The phasing method is based on a high-aperture Michelson interferometer. The use of an interferometric technique allows the measuring of segment misalignment during the daytime with high accuracy, which is a major design guideline. The innovation introduced in the optical design of the interferometer is the simultaneous use of monochromatic light and multiwavelength combination white-light source in a direct method for improving the central fringe identification in the white-light interferometric phasing system. With theoretic analysis, we find that this multiwavelength combination technique can greatly increase the visibility difference between the central fringe and its adjacent side fringes, and thus it offers an increased signal resolution. So make the central fringe identification become easier, and enhance the measure precision of the segment phasing error. Consequently, it is suitable for

  12. The Development and Mission of the Space Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Gallagher, David B.; Irace, William R.; Werner, Michael W.

    2004-01-01

    This paper provides an overview of the SIRTF mission, telescope, cryostat, instruments, spacecraft, orbit, operations and project management approach; and this paper serves as an introduction to the accompanying set of detailed papers about specific aspects of SIRTF.

  13. Shuttle infrared telescope facility (SIRTF) preliminary design study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An overall picture of the SIRTF system is first presented, including the telescope, focal plane instruments, cryogen supply, shuttle and spacelab support subsystems, mechanical and data interfaces with the vehicles, ground support equipment, and system requirements. The optical, mechanical, and thermal characteristics of the telescope are then evaluated, followed by a description of the SIRTF internal stabilization subsystem and its interface with the IPS. Expected performance in the shuttle environment is considered. Tradeoff studies are described, including the Gregorian versus the Cassegrain telescope, aperture diameter tradeoff, a CCD versus an image dissector for the star tracker, the large ambient telescope versus the SIRTF, and a dedicated gimbal versus the IPS. Operations from integration through launch and recovery are also discussed and cost estimates for the program are presented.

  14. Interferometric Near-Infrared Spectroscopy (iNIRS) for determination of optical and dynamical properties of turbid media

    PubMed Central

    Borycki, Dawid; Kholiqov, Oybek; Chong, Shau Poh; Srinivasan, Vivek J.

    2016-01-01

    We introduce and implement interferometric near-infrared spectroscopy (iNIRS), which simultaneously extracts optical and dynamical properties of turbid media through analysis of a spectral interference fringe pattern. The spectral interference fringe pattern is measured using a Mach-Zehnder interferometer with a frequency-swept narrow linewidth laser. Fourier analysis of the detected signal is used to determine time-of-flight (TOF)-resolved intensity, which is then analyzed over time to yield TOF-resolved intensity autocorrelations. This approach enables quantification of optical properties, which is not possible in conventional, continuous-wave near-infrared spectroscopy (NIRS). Furthermore, iNIRS quantifies scatterer motion based on TOF-resolved autocorrelations, which is a feature inaccessible by well-established diffuse correlation spectroscopy (DCS) techniques. We prove this by determining TOF-resolved intensity and temporal autocorrelations for light transmitted through diffusive fluid phantoms with optical thicknesses of up to 55 reduced mean free paths (approximately 120 scattering events). The TOF-resolved intensity is used to determine optical properties with time-resolved diffusion theory, while the TOF-resolved intensity autocorrelations are used to determine dynamics with diffusing wave spectroscopy. iNIRS advances the capabilities of diffuse optical methods and is suitable for in vivo tissue characterization. Moreover, iNIRS combines NIRS and DCS capabilities into a single modality. PMID:26832264

  15. An Interferometric Study of the Fomalhaut Inner Debris Disk. I. Near-Infrared Detection of Hot Dust with VLTI/VINCI

    NASA Astrophysics Data System (ADS)

    Absil, Olivier; Mennesson, Bertrand; Le Bouquin, Jean-Baptiste; Di Folco, Emmanuel; Kervella, Pierre; Augereau, Jean-Charles

    2009-10-01

    The innermost parts of dusty debris disks around main-sequence stars are currently poorly known due to the high contrast and small angular separation with their parent stars. Using near-infrared interferometry, we aim to detect the signature of hot dust around the nearby A4 V star Fomalhaut, which has already been suggested to harbor a warm dust population in addition to a cold dust ring located at about 140 AU. Archival data obtained with the VINCI instrument at the VLTI are used to study the fringe visibility of the Fomalhaut system at projected baseline lengths ranging from 4 m to 140 m in the K band. A significant visibility deficit is observed at short baselines with respect to the expected visibility of the sole stellar photosphere. This is interpreted as the signature of resolved circumstellar emission, producing a relative flux of 0.88% ± 0.12% with respect to the stellar photosphere. While our interferometric data cannot directly constrain the morphology of the excess emission source, complementary data from the literature allow us to discard an off-axis point-like object as the source of circumstellar emission. We argue that the thermal emission from hot dusty grains located within 6 AU from Fomalhaut is the most plausible explanation for the detected excess. Our study also provides a revised limb-darkened diameter for Fomalhaut (θLD = 2.223 ± 0.022 mas), taking into account the effect of the resolved circumstellar emission. Based on observations made with ESO Telescopes at the Paranal Observatory (public VINCI commissioning data).

  16. Imaging telescope-spectrometer for infrared sky surveys

    NASA Astrophysics Data System (ADS)

    Maslov, Igor A.; Sholomitskii, Gennadii B.; Kuznetsov, Arkadii E.; Patrashin, Michail A.; Olejnikov, Leonid S.

    1995-06-01

    A new type of imaging telescope-spectrometer for surviving the sky aboard a satellite is described. A static Michelson interferometer in front of an objective with 2D-arrays in its focal plane is capable of providing interferograms both for point and extended sources. As an example, the telescope-spectrometer based on the 15-cm telescope of the IKON project and a plane-parallel Ge plate as a beamsplitter may have approximately equals 30 cm(superscript -1 spectral resolution in the range 3 - 20 micrometers . For higher resolution, such an objective interferometer has advantage over a dispersion spectrometer in the signal-to-noise ratio and is free from the disadvantage of an objective prism not providing spectra of extended sources.

  17. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    NASA Technical Reports Server (NTRS)

    Feinberg, Lee; Bolcar, Matt; Liu, Alice; Guyon, Olivier; Stark,Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.

  18. The Space Infrared Interferometric Telescope (SPIRIT): High-Resolution Imaging and Spectroscopy in the Far-Infrared (Preprint)

    DTIC Science & Technology

    2007-01-01

    characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different...characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different types form...composition; (2) characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of

  19. Design of a white-light interferometric measuring system for co-phasing the primary mirror segments of the next generation of ground-based telescope

    NASA Astrophysics Data System (ADS)

    Song, Helun; Xian, Hao; Jiang, Wenhan; Rao, Changhui; Wang, Shengqian

    2007-12-01

    With the increase of telescope size, the manufacture of monolithic primaries becomes increasingly difficult. Instead, the use of segmented mirrors, where many individual mirrors (the segments) work together to provide good image quality and an aperture equivalent to that of a large monolithic mirror, is considered a more appropriate strategy. But, with the introduction of large telescope mirror comprised of many individual segments, the problem of insuring a smooth continuous mirror surface (co-phased mirrors) becomes critical. One of the main problems arising in the co-phasing of the segmented mirrors telescope is the problem of measurements of the vertical displacements between the individual segments (piston errors). Because of such mirrors to exhibit diffraction-limited performance, a phasing process is required in order to guarantee that the segments have to be positioned with an accuracy of a fraction of a wavelength of the incoming light.The measurements become especially complicated when the piston error is in order of wavelength fractions. To meet the performance capabilities, a novel method for phasing the segmented mirrors optical system is described. The phasing method is based on a high-aperture Michelson interferometer. The use of an interferometric technique allows the measurement of segment misalignment during daytime with high accuracy, which is a major design guideline. The innovation introduced in the optical design of the interferometer is the simultaneous use of both monochromatic and white-light sources that allows the system to measure the piston error with an uncertainty of 6nm in 50µm range. The description about the expected monochromatic and white-light illumination interferograms and the feasibility of the phasing method are presented here.

  20. Infrared Observations with the 1.6 Meter New Solar Telescope in Big Bear: Origins of Space Weather

    DTIC Science & Technology

    2015-05-21

    COVERED (From - To)      01-04-2012 to 31-03-2015 4.  TITLE AND SUBTITLE Infrared Observations with the 1.6 Meter New Solar Telescope in Big Bear : Origins...utilized the 1.6 m clear aperture solar telescope in Big Bear Lake, CA. This telescope is the largest aperture and most powerful solar telescope ever...solar telescope in Big Bear Lake, CA. This telescope is the largest aperture and most powerful solar telescope ever built, which enable the high

  1. Submillimeter astronomy at the NASA/University of Hawaii 3-meter infrared telescope facility

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Problems encountered in the design of a submillimeter photometer for the infrared telescope facility and some of the solutions already provided are described. Observations of Saturn's rings and the determination of the brightness temperature of Titan, Jupiter, Saturn, Neptune, and Uranus are summarized. Significant findings during solar, galactic, and extragalactic observations include the discovery of low luminosity star formation in the Bok Globule B335 and determination of the far infrared properties of dust in the reflection nebula NGC 7023.

  2. Wide Field Infrared Survey Telescope [WFIRST]: Telescope Design and Simulated Performance

    NASA Technical Reports Server (NTRS)

    Goullioud, R.; Content, D. A.; Kuan, G. M.; Moore, J. D.; Chang, Z.; Sunada, E. T.; Villalvazo, J.; Hawk, J. P.; Armani, N. V.; Johnson, E. L.; Powell, C. A.

    2012-01-01

    The ASTRO2010 Decadal Survey proposed multiple missions with NIR focal planes and 3 mirror wide field telescopes in the 1.5m aperture range. None of them would have won as standalone missions WFIRST is a combination of these missions, created by Astro 2010 committee. WFIRST Science Definition Team (SDT) tasked to examine the design. Project team is a GSFC-JPL-Caltech collaboration. This interim mission design is a result of combined work by the project team with the SDT.

  3. Design Evolution of the Wide Field Infrared Survey Telescope Using Astrophysics Focused Telescope Assets (WFIRST-AFTA) and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Peabody, Hume L.; Peters, Carlton V.; Rodriguez-Ruiz, Juan E.; McDonald, Carson S.; Content, David A.; Jackson, Clifton E.

    2015-01-01

    The design of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) continues to evolve as each design cycle is analyzed. In 2012, two Hubble sized (2.4 m diameter) telescopes were donated to NASA from elsewhere in the Federal Government. NASA began investigating potential uses for these telescopes and identified WFIRST as a mission to benefit from these assets. With an updated, deeper, and sharper field of view than previous design iterations with a smaller telescope, the optical designs of the WFIRST instruments were updated and the mechanical and thermal designs evolved around the new optical layout. Beginning with Design Cycle 3, significant analysis efforts yielded a design and model that could be evaluated for Structural-Thermal-Optical-Performance (STOP) purposes for the Wide Field Imager (WFI) and provided the basis for evaluating the high level observatory requirements. Development of the Cycle 3 thermal model provided some valuable analysis lessons learned and established best practices for future design cycles. However, the Cycle 3 design did include some major liens and evolving requirements which were addressed in the Cycle 4 Design. Some of the design changes are driven by requirements changes, while others are optimizations or solutions to liens from previous cycles. Again in Cycle 4, STOP analysis was performed and further insights into the overall design were gained leading to the Cycle 5 design effort currently underway. This paper seeks to capture the thermal design evolution, with focus on major design drivers, key decisions and their rationale, and lessons learned as the design evolved.

  4. Design Evolution of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Peabody, Hume; Peters, Carlton; Rodriguez, Juan; McDonald, Carson; Content, David A.; Jackson, Cliff

    2015-01-01

    The design of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) continues to evolve as each design cycle is analyzed. In 2012, two Hubble sized (2.4 m diameter) telescopes were donated to NASA from elsewhere in the Federal Government. NASA began investigating potential uses for these telescopes and identified WFIRST as a mission to benefit from these assets. With an updated, deeper, and sharper field of view than previous design iterations with a smaller telescope, the optical designs of the WFIRST instruments were updated and the mechanical and thermal designs evolved around the new optical layout. Beginning with Design Cycle 3, significant analysis efforts yielded a design and model that could be evaluated for Structural-Thermal-Optical-Performance (STOP) purposes for the Wide Field Imager (WFI) and provided the basis for evaluating the high level observatory requirements. Development of the Cycle 3 thermal model provided some valuable analysis lessons learned and established best practices for future design cycles. However, the Cycle 3 design did include some major liens and evolving requirements which were addressed in the Cycle 4 Design. Some of the design changes are driven by requirements changes, while others are optimizations or solutions to liens from previous cycles. Again in Cycle 4, STOP analysis was performed and further insights into the overall design were gained leading to the Cycle 5 design effort currently underway. This paper seeks to capture the thermal design evolution, with focus on major design drivers, key decisions and their rationale, and lessons learned as the design evolved.

  5. RIN-suppressed ultralow noise interferometric fiber optic gyroscopes (IFOGs) for improving inertial stabilization of space telescopes

    NASA Astrophysics Data System (ADS)

    Hakimi, Farhad; Moores, John D.

    2013-03-01

    Pointing, acquisition, and tracking (PAT) systems in spaceborne optical communications terminals can exploit inertial sensors and actuators to counter platform vibrations and maintain steady beam pointing. Interferometric fiber optic gyroscopes (IFOGs) can provide sensitive angle rate measurements down to very low (sub-milliHertz) mechanical frequencies, potentially reducing the required beacon power and facilitating acquisition for a spaceborne optical communications terminals. Incoherent broadband light sources are used in IFOGs to alleviate detrimental effects of optical nonlinearities, backscattering, and polarization non-reciprocity. But incoherent broadband sources have excess noise or relative intensity noise (RIN), caused by the beating of different spectral components on the photodetector. Unless RIN noise is suppressed, IFOG performance cannot be improved once the light on the photodetector exceeds one photon per coherence time (~microWatts). We propose a simple method to dramatically suppress the RIN of an incoherent light source and thereby reduce the angle random walk (ARW) of an IFOG using such a source. We demonstrate 20 dB RIN suppression of a broadband EDFA source, which we predict could improve the angle random walk (ARW) of an IFOG using this source by 12 dB.

  6. Infra-red lamp panel study and assessment application to thermal vacuum testing of sigma telescope

    NASA Technical Reports Server (NTRS)

    Mauduyt, Jacques; Merlet, Joseph; Poux, Christiane

    1986-01-01

    A research and development program of the Infra-Red Test has been conducted by the French Space Agency (CNES). A choice, after characterization, among several possibilities has been made on the type of methods and facilities for the I.R. test. An application to the Thermal Vacuum Test of the SIGMA Telescope is described.

  7. Postupgrade performance of the 3.8-m United Kingdom Infrared Telescope (UKIRT)

    NASA Astrophysics Data System (ADS)

    Hawarden, Timothy G.; Rees, Nicholas P.; Chuter, Timothy C.; Chrysostomou, Antonio C.; Cavedoni, Charles P.; Rohloff, Ralf-Rainer; Pitz, Eckhart; Pettie, Donald G.; Bennett, Richard J.; Atad-Ettedgui, Eli

    1999-10-01

    The upgraded 3.8 m UK Infrared Telescope is now provided with: (1) tip-tilt image stabilization by a light-weighted secondary mirror on piezo-electric actuators, controlled by a fast guider sampling at >= 40 Hz on guide stars V

  8. An Interferometric Study of the Fomalhaut Inner Debris Disk. II. Keck Nuller Mid-infrared Observations

    NASA Astrophysics Data System (ADS)

    Mennesson, B.; Absil, O.; Lebreton, J.; Augereau, J.-C.; Serabyn, E.; Colavita, M. M.; Millan-Gabet, R.; Liu, W.; Hinz, P.; Thébault, P.

    2013-02-01

    We report on high-contrast mid-infrared observations of Fomalhaut obtained with the Keck Interferometer Nuller (KIN) showing a small resolved excess over the level expected from the stellar photosphere. The measured null excess has a mean value of 0.35% ± 0.10% between 8 and 11 μm and increases from 8 to 13 μm. Given the small field of view of the instrument, the source of this marginal excess must be contained within 2 AU of Fomalhaut. This result is reminiscent of previous VLTI K-band (sime2μm) observations, which implied the presence of a ~0.88% excess, and argued that thermal emission from hot dusty grains located within 6 AU from Fomalhaut was the most plausible explanation. Using a parametric two-dimensional radiative transfer code and a Bayesian analysis, we examine different dust disk structures to reproduce both the near- and mid-infrared data simultaneously. While not a definitive explanation of the hot excess of Fomalhaut, our model suggests that the most likely inner few AU disk geometry consists of a two-component structure, with two different and spatially distinct grain populations. The 2-11 μm data are consistent with an inner hot ring of very small (sime10-300 nm) carbon-rich grains concentrating around 0.1 AU. The second dust population—inferred from the KIN data at longer mid-infrared wavelengths—consists of larger grains (size of a few microns to a few tens of microns) located further out in a colder region where regular astronomical silicates could survive, with an inner edge around 0.4 AU-1 AU. From a dynamical point of view, the presence of the inner concentration of submicron-sized grains is surprising, as such grains should be expelled from the inner planetary system by radiation pressure within only a few years. This could either point to some inordinate replenishment rates (e.g., many grazing comets coming from an outer reservoir) or to the existence of some braking mechanism preventing the grains from moving out.

  9. High performance testbed for four-beam infrared interferometric nulling and exoplanet detection.

    PubMed

    Martin, Stefan; Booth, Andrew; Liewer, Kurt; Raouf, Nasrat; Loya, Frank; Tang, Hong

    2012-06-10

    Technology development for a space-based infrared nulling interferometer capable of earthlike exoplanet detection and characterization started in earnest in the last 10 years. At the Jet Propulsion Laboratory, the planet detection testbed was developed to demonstrate the principal components of the beam combiner train for a high performance four-beam nulling interferometer. Early in the development of the testbed, the importance of "instability noise" for nulling interferometer sensitivity was recognized, and the four-beam testbed would produce this noise, allowing investigation of methods for mitigating this noise source. The testbed contains the required features of a four-beam combiner for a space interferometer and performs at a level matching that needed for the space mission. This paper describes in detail the design, functions, and controls of the testbed.

  10. Collision of comet Shoemaker-Levy 9 with Jupiter observed by the NASA infrared telescope facility.

    PubMed

    Orton, G; A'Hearn, M; Baines, K; Deming, D; Dowling, T; Goguen, J; Griffith, C; Hammel, H; Hoffmann, W; Hunten, D

    1995-03-03

    The National Aeronautics and Space Administration (NASA) Infrared Telescope Facility was used to investigate the collision of comet Shoemaker-Levy 9 with Jupiter from 12 July to 7 August 1994. Strong thermal infrared emission lasting several minutes was observed after the impacts of fragments C, G, and R. All impacts warmed the stratosphere and some the troposphere up to several degrees. The abundance of stratospheric ammonia increased by more than 50 times. Impact-related particles extended up to a level where the atmospheric pressure measured several millibars. The north polar near-infrared aurora brightened by nearly a factor of 5 a week after the impacts.

  11. Collision of comet Shoemaker-Levy 9 with Jupiter observed by the NASA infrared telescope facility

    NASA Technical Reports Server (NTRS)

    Orton, G.; A'Hearn, M.; Baines, K.; Deming, D.; Dowling, T.; Goguen, J.; Griffith, C.; Hammel, H.; Hoffmann, W.; Hunten, D.; Zahnle, K. (Principal Investigator)

    1995-01-01

    The National Aeronautics and Space Administration (NASA) Infrared Telescope Facility was used to investigate the collision of comet Shoemaker-Levy 9 with Jupiter from 12 July to 7 August 1994. Strong thermal infrared emission lasting several minutes was observed after the impacts of fragments C, G, and R. All impacts warmed the stratosphere and some the troposphere up to several degrees. The abundance of stratospheric ammonia increased by more than 50 times. Impact-related particles extended up to a level where the atmospheric pressure measured several millibars. The north polar near-infrared aurora brightened by nearly a factor of 5 a week after the impacts.

  12. Wide Field Infra-Red Survey Telescope (WFIRST) 2.4-Meter Mission Study

    NASA Technical Reports Server (NTRS)

    Content, D.; Aaron, K.; Alplanalp, L.; Anderson, K.; Capps, R.; Chang, Z.; Dooley, J.; Egerman, R.; Goullioud, R.; Klein, D.; Kruk, J.; Kuan, G.; Melton, M.; Ruffa, J.; Underhill, M.; Buren, D. Van

    2013-01-01

    The most recent study of the Wide Field Infrared Survey Telescope (WFIRST) mission is based on reuse of an existing 2.4m telescope. This study was commissioned by NASA to examine the potential science return and cost effectiveness of WFIRST by using this significantly larger aperture telescope. We review the science program envisioned by the WFIRST 2012-2013 Science Definition Team (SDT), an overview of the mission concept, and the telescope design and status. Comparisons against the previous 1.3m and reduced cost 1.1m WFIRST design concepts are discussed. A significant departure from past point designs is the option for serviceability and the geostationary orbit location which enables servicing and replacement instrument insertion later during mission life. Other papers at this conference provide more in depth discussion of the wide field instrument and the optional exoplanet imaging coronagraph instrument.

  13. Small helium-cooled infrared telescope experiment for Spacelab-2 (IRT)

    NASA Technical Reports Server (NTRS)

    Fazio, Giovanni G.

    1990-01-01

    The Infrared Telescope (IRT) experiment, flown on Spacelab-2, was used to make infrared measurements between 2 and 120 microns. The objectives were multidisciplinary in nature with astrophysical goals of mapping the diffuse cosmic emission and extended infrared sources and technical goals of measuring the induced Shuttle environment, studying properties of superfluid helium in space, and testing various infrared telescope system designs. Astrophysically, new data were obtained on the structure of the Galaxy at near-infrared wavelengths. A summary of the large scale diffuse near-infrared observations of the Galaxy by the IRT is presented, as well as a summary of the preliminary results obtained from this data on the structure of the galactic disk and bulge. The importance of combining CO and near-infrared maps of similar resolution to determine a 3-D model of galactic extinction is demonstrated. The IRT data are used, in conjunction with a proposed galactic model, to make preliminary measurements of the global scale parameters of the Galaxy. During the mission substantial amounts of data were obtained concerning the induced Shuttle environment. An experiment was also performed to measure spacecraft glow in the IR.

  14. A project for an infrared synoptic survey from Antarctica with the Polar Large Telescope (PLT)

    NASA Astrophysics Data System (ADS)

    Epchtein, N.; Abe, L.; Ansorge, W.; Langlois, M.; Vauglin, I.; Argentini, S.; Esau, I.; David, C.; Bryson, I.; Dalton, G.; Ashley, M. C. B.; Lawrence, J. S.

    2011-12-01

    The Polar Large Telescope (PLT) aims at performing a new generation of astronomical Infrared Synoptic Survey from Antarctica (ISSA). It would carry out for the first time large scale periodic imaging surveys at ˜ 0.3 arcsec angular resolution in the short thermal infrared (2-5 micron) range benefiting from the extremely dry, cold, and stable polar atmosphere. The PLT consists of a 2.5 m class telescope equipped with a 250-Mpixel infrared camera. The survey would produce diffraction limited images at 2 micron covering a total of ˜ 5000 square degrees, explore the time domain from seconds to years down to mab =25.5 in Kd, generate alerts of transients and react quickly to alerts from other ground based or space borne facilities.

  15. Interferometric Astrometry of Proxima Centauri and Barnard's Star Using HUBBLE SPACE TELESCOPE Fine Guidance Sensor 3: Detection Limits for Substellar Companions

    NASA Astrophysics Data System (ADS)

    Benedict, G. Fritz; McArthur, Barbara; Chappell, D. W.; Nelan, E.; Jefferys, W. H.; van Altena, W.; Lee, J.; Cornell, D.; Shelus, P. J.; Hemenway, P. D.; Franz, Otto G.; Wasserman, L. H.; Duncombe, R. L.; Story, D.; Whipple, A. L.; Fredrick, L. W.

    1999-08-01

    We report on a substellar-companion search utilizing interferometric fringe-tracking astrometry acquired with Fine Guidance Sensor 3 on the Hubble Space Telescope. Our targets were Proxima Centauri and Barnard's star. We obtain absolute parallax values of pi_abs=0.7687"+/-0.0003" for Proxima Cen and pi_abs=0.5454"+/-0.0003" for Barnard's star. Once low-amplitude instrumental systematic errors are identified and removed, our companion detection sensitivity is less than or equal to one Jupiter mass for periods longer than 60 days for Proxima Cen. Between the astrometry and the recent radial velocity results of Kürster et al., we exclude all companions with M>0.8M_Jup for the range of periods 1 day

  16. Performance of the restoration of interferometric images from the Large Binocular Telescope: the effects of angular coverage and partial adaptive optics correction

    NASA Astrophysics Data System (ADS)

    Carbillet, Marcel; Correia, Serge; Boccacci, Patrizia; Bertero, Mario

    2003-02-01

    This presentation reports the status of our study concerning the imaging properties of the Large Binocular Telescope (LBT) interferometer, and namely the effect of limited angular coverage and partial adaptive optics (AO) correction. The limitation in angular coverage, together with the correlated problem of angular smearing due to time-averaging of the interferometric images, is investigated for relevant cases depending on the declination of the observed object. Results are encouraging even in case of incomplete coverage. Partial AO-correction can result in a wide range of image quality, but can also create significant differences within a same field-of-view, especially between a suitable reference star to be used for post-observation multiple deconvolution and the observed object. Our study deals with both the problem of space-variance of the AO-corrected point-spread function, and that of global quality of the AO-correction. Uniformity, rather than global quality, is found to be the key-problem. After considering the single-conjugate AO case, we reach to some conclusions for the more interesting, and actually wide-field, case implying multi-conjugate AO. The whole study is performed on different types of object, from binary stars to diffuse objects, and a combined one with a high-dynamic range.

  17. A New Prime Focus Camera for the Wyoming Infrared Telescope

    NASA Astrophysics Data System (ADS)

    Pierce, M. J.; Nations, H. L.

    2002-05-01

    We describe the new prime-focus, optical imaging camera for the Wyoming Infrared Observatory (WIRO). A 3-element Wynne corrector produces a well-corrected field of 18 arcmin at the f/2.1 focus of the 2.3-m primary of WIRO. The camera consists of a Marconi 2k x 2k detector housed in a camera/controller from Astronomical Research Cameras, Inc. The resulting scale of 0.6 arcsec per 13.5 um pixel is well-matched to the expected seeing for this site. The filter wheel, corrector position, and instrument focus are controlled using a GUI written in Visual Basic. We find this environment to be particularly efficient for simple instrumentation development. We present preliminary measures of the image quality and throughput for the camera as well as a brief description of some of the survey projects planned for this instrument.

  18. Optical and infrared backgrounds from the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Dolch, Timothy

    The sum total of the energy released by the earliest era of star formation should show up today within the diffuse extragalactic background light (EBL), its signature peaking in the near-infrared. There is considerable controversy over estimates of the average EBL per steradian at optical and infrared wavelengths, over measurements of background fluctuations, and over the interpretation of the measurements. Resolving this controversy is important because the EBL constrains the history of galaxy evolution. The fluctuations and their colors may also contain important information about Population III stars and the earliest era of star formation. We compare number counts from recent galaxy surveys, correcting for their differing passbands. With some assumptions about galaxy sizes and surface-brightness profiles, we account for the light missed in standard photometric estimates, integrating the resulting corrected counts to estimate the total EBL due to resolved galaxies as well as undetected galaxies. We then present an analysis of background fluctuations in observations of the HUDF, the GOODS field, and the CANDELS fields obtained with WFC3. The fluctuation signal provides a constraint on the slope of galaxy counts fainter than the levels of individual detection, as well as their typical angular sizes. The color dependence of the fluctuations provides a constraint on the redshift distribution of these very faint sources. The spatial and spectral information from these anisotropies, even in their non-detection, provide valuable information about the era of reionization, when the first stars and galaxies formed. Via various analysis tools such as power spectra and P(D) fitting, best-fit models to faint sources can be obtained.

  19. Wavefront Sensing and Control Technology for Submillimeter and Far-Infrared Space Telescopes

    NASA Technical Reports Server (NTRS)

    Redding, Dave

    2004-01-01

    The NGST wavefront sensing and control system will be developed to TRL6 over the next few years, including testing in a cryogenic vacuum environment with traceable hardware. Doing this in the far-infrared and submillimeter is probably easier, as some aspects of the problem scale with wavelength, and the telescope is likely to have a more stable environment; however, detectors may present small complications. Since this is a new system approach, it warrants a new look. For instance, a large space telescope based on the DART membrane mirror design requires a new actuation approach. Other mirror and actuation technologies may prove useful as well.

  20. A CCD camera for guidance of 100-cm balloon-borne far-infrared telescope

    NASA Astrophysics Data System (ADS)

    D'Costa, S. L.; Ghosh, S. K.; Tandon, S. N.

    1991-08-01

    A charge coupled device (CCD) camera using the 488 x 380 element Fairchild CCD 222 imaging device has been developed for guidance of the 100 cm balloonborne far infrared telescope. The hardware consists of an imaging device along with its associated optics, a clock generating circuitry, the clock drivers, an 8086 microprocessor-based system, and the power supplies. The software processes the CCD image data and uses a selected star in its field of view as the guide star for pointing the telescope with an accuracy of around 4 arc s.

  1. United Kingdom Infrared Telescope's Spectrograph Observations of Human-Made Space Objects

    NASA Technical Reports Server (NTRS)

    Buckalew, Brent; Abercromby, Kira; Lederer, Susan; Cowardin, Heather; Frith, James

    2017-01-01

    Presented here are the results of the United Kingdom Infrared Telescope (UKIRT) spectral observations of human-made space objects taken from 2014 to 2015. The data collected using the UKIRT 1-5 micron Imager Spectrometer (UIST) cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 18 different orbiting objects at or near geosynchronous orbit (GEO). Two of the objects are controlled spacecraft, twelve are non-controlled spacecraft, one is a rocket body, and three are cataloged as debris. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials; thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons and silicon. The spacecraft, both the controlled and non-controlled, show distinct features due to the presence of solar panels whereas the rocket bodies do not. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give well-correlated indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. A comparison conducted between objects observed previously with the NASA Infrared Telescope Facility (IRTF) shows similar materials and trends from the two telescopes and different times. However, based on the current state of the model, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft

  2. Spartan Infrared Camera, a High-Resolution Imager for the SOAR Telescope: Design, Tests, and On-Telescope Performance

    NASA Astrophysics Data System (ADS)

    Loh, Edwin D.; Biel, Jason D.; Davis, Michael W.; Laporte, René; Loh, Owen Y.; Verhanovitz, Nathan J.

    2012-04-01

    The Spartan Infrared Camera provides tip-tilt corrected imaging for the SOAR Telescope in the 900–2500 nm spectral range with four 2048 × 2048 HAWAII-2 detectors. The camera has two plate scales: high-resolution () for future diffraction-limited sampling in the H and K bands and wide-field () to cover a 5‧ × 5‧ field, over which tip-tilt correction is substantial. The design is described in detail. Except for CaF2 field-flattening lenses, the optics are aluminum mirrors to thermally match the aluminum cryogenic-optical box in which the optics mount. The design minimizes the tilt of the optics as the instrument rotates on the Nasmyth port of the telescope. Two components of the gravitational torque on an optic are eliminated by symmetry, and the third component is minimized by balancing the optic. The optics (including the off-axis aspherical mirrors) were aligned with precise metrology. For the detector assembly, Henein pivots are used to provide frictionless, thermally compliant, lubricant-free, and thermally conducting rotation of the detectors. The heat load is 14 W for an ambient temperature of 10°C. Cooling down takes 40 hr. An activated-charcoal getter controls permeation through the large Viton O-ring for at least nine months. We present maps of the image distortion, which amount to tens of pixels at the greatest. The wavelength of the narrowband filters shift with position in the sky. The measured Strehl ratio of the camera itself is 0.81–0.84 at λ1650 nm. The width of the best K-band image was 260 mas in unexceptional seeing measured after tuning the telescope and before moving the telescope. Since images are normally taken after pointing the telescope to a different field, this supports the idea that the image quality could be improved by better control of the focus and the shape of the primary mirror. The instrument has proved to be capable of producing images that can be stitched together to measure faint, extended features and to produce

  3. Prediction of the Vibroacoustic Response of the Equipment Mounted on the Infrared Space Telescope "SPICA"

    NASA Astrophysics Data System (ADS)

    Akagi, Hiroki; Ando, Shigemasa; Shi, Qinzhong; Yamawaki, Toshiko

    2014-06-01

    The infrared space telescope "SPICA" (Space Infrared Telescope for Cosmology and Astrophysics) is a structurally-complex spacecraft, which requires the less conservative prediction of the random vibration at interface in order to reduce the over-margin issue for designing the strength on critical structure of optical instrument in the early stage of development, and to relieve the risk of overweight designing. This paper proposes Combination of FEA and SEA Methods to predict the vibroacoustic response of the equipment mounted on SPICA, and less conservative specification of the random vibration environments. Furthermore, a method of force-limiting to notch the specification over a certain frequency range during designing and a random vibration test is shown. Force-limiting specification is calculated using a simplified approach by multiplying the article's apparent mass to the equivalent of vibroacoustic response at interface.

  4. Optical and near infrared observations of the blazar 3C 279 with the REM telescope.

    NASA Astrophysics Data System (ADS)

    Impiombato, D.; Tosti, G.; Ciprini, C.; REM Collaboration.

    The Rapid Eye Mount (REM) telescope installed at La Silla (Cile) on June 2003, is a robotic telescope able the capability to observe in optical and infrared bands. Since the late commissioning phase a optical and infrared monitoring program of a sample of blazars, most emitting also in the gamma-ray band, was started. Such program is still on going and it make part of an observational activity aimed to the multiwavelength characterization possible blazars candidate to be observed also in gamma-ray by the instruments on board of AGILE satellites(launched on 23 April 2007) and Glast (that will be launched at the end of the 2007). In this poster we present the optical/near-IR data obtained during the January 2007, outburst of 3C279 (the prototype of the gamma-ray loud).

  5. Optical Design Trade Study for the Wide Field Infrared Survey Telescope [WFIRST

    NASA Technical Reports Server (NTRS)

    Content, David A.; Goullioud, R.; Lehan, John P.; Mentzell, John E.

    2011-01-01

    The Wide Field Infrared Survey Telescope (WFIRST) mission concept was ranked first in new space astrophysics mission by the Astro2010 Decadal Survey incorporating the Joint Dark Energy Mission (JDEM)-Omega payload concept and multiple science white papers. This mission is based on a space telescope at L2 studying exoplanets [via gravitational microlensing], probing dark energy, and surveying the near infrared sky. Since the release of NWNH, the WFIRST project has been working with the WFIRST science definition team (SDT) to refine mission and payload concepts. We present the driving requirements. The current interim reference mission point design, based on the use of a 1.3m unobscured aperture three mirror anastigmat form, with focal imaging and slitless spectroscopy science channels, is consistent with the requirements, requires no technology development, and out performs the JDEM-Omega design.

  6. End-to-end assessment of a large aperture segmented ultraviolet optical infrared (UVOIR) telescope architecture

    NASA Astrophysics Data System (ADS)

    Feinberg, Lee; Rioux, Norman; Bolcar, Matthew; Liu, Alice; Guyon, Olivier; Stark, Chris; Arenberg, Jon

    2016-07-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield exo-earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an exo-earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and exo-earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling these missions.

  7. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    NASA Technical Reports Server (NTRS)

    Feinberg, Lee; Rioux, Norman; Bolcar, Matthew; Liu, Alice; Guyon, Oliver; Stark, Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it.

  8. Balloon-borne three-meter telescope for far-infrared and submillimeter astronomy

    NASA Technical Reports Server (NTRS)

    Fazio, G. G.

    1985-01-01

    Presented are scientific objectives, engineering analysis and design, and results of technology development for a Three-Meter Balloon-Borne Far-Infrared and Submillimeter Telescope. The scientific rationale is based on two crucial instrumental capabilities: high angular resolution which approaches eight arcseconds at one hundred micron wavelength, and high resolving power spectroscopy with good sensitivity throughout the telescope's 30-micron to 1-mm wavelength range. The high angular resolution will allow us to resolve and study in detail such objects as collapsing protostellar condensations in our own galaxy, clusters of protostars in the Magellanic clouds, giant molecular clouds in nearby galaxies, and spiral arms in distant galaxies. The large aperture of the telescope will permit sensitive spectral line measurements of molecules, atoms, and ions, which can be used to probe the physical, chemical, and dynamical conditions in a wide variety of objects.

  9. Pointing and control system design study for the space infrared telescope facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Lorell, K. R.; Aubrun, J. N.; Sridhar, B.; Cochran, R. W.

    1984-01-01

    The design and performance of pointing and control systems for two space infrared telescope facility vehicles were examined. The need for active compensation of image jitter using the secondary mirror or other optical elements was determined. In addition, a control system to allow the telescope to perform small angle slews, and to accomplish large angle slews at the rate of 15 deg per minute was designed. Both the 98 deg and the 28 deg inclination orbits were examined, and spacecraft designs were developed for each. The results indicate that active optical compensation of line-of-sight errors is not necessary if the system is allowed to settle for roughly ten seconds after a slew maneuver. The results are contingent on the assumption of rigid body dynamics, and a single structural mode between spacecraft and telescope. Helium slosh for a half full 4000 liter tank was analyzed, and did not represent a major control problem.

  10. Design and performance of transfer assembly for the infrared telescope for Space Lab 2. [cryogenic system

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    The cryogenic design features employed in the case of the Infrared Telescope (IRT) for Spacelab 2 are unique. They involve the delivery of helium gas at a temperature of 2 K to the IR detectors from a superfluid supply dewar which is separate from the telescope/detector unit. This design has the advantage that thermal and mechanical vibration disturbances in the liquid helium bath are decoupled from the IR detector. The interfacing of the storage dewar with the IRT telescope/detector unit (called cryostat) is the function of the subsystem which is called the transfer assembly (TA). The TA design is discussed, taking into account the porous plug module, the plumbing module, the helix module, and the dewar heat exchanger units. Aspects of transfer assembly performance are also considered.

  11. Autonomous Observing and Control Systems for PAIRITEL, a 1.3m Infrared Imaging Telescope

    NASA Astrophysics Data System (ADS)

    Bloom, J. S.; Starr, D. L.; Blake, C. H.; Skrutskie, M. F.; Falco, E. E.

    2006-07-01

    The Peters Automated Infrared Imaging Telescope (PAIRITEL) is the first meter-class telescope operating as a fully robotic IR imaging system. Dedicated in October 2004, PAIRITEL began regular observations in mid-December 2004 as part of a 1.5 year commissioning period. The system was designed to respond without human intervention to new gamma-ray burst transients: this milestone was finally reached on November 9, 2005 but the telescope had a number of semi-automated sub-10 minute responses throughout early commissioning. When not operating in Target of Opportunity mode, PAIRITEL performs a number of queue scheduled transient monitoring campaigns. To achieve this level of automation, we have developed communicating tools to connect the various sub-systems: an intelligent queue scheduling database, run-time configurable observation sequence software, a data reduction pipeline, and a master state machine which monitors and controls all functions within and affecting the observatory.

  12. 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.

  13. A conceptual design study for the secondary mirror drive of the shuttle infrared telescope facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Sager, R. E.; Cox, D. W.

    1983-01-01

    Various conceptual designs for the secondary mirror actuator system to be used in the Shuttle Infrared Telescope Facility (SIRTF) were evaluated. In addition, a set of design concepts was developed to assist in the solution of problems crucial for optimum performance of the secondary mirror actuator system. A specific conceptual approach was presented along with a plan for developing that approach and identifying issues of critical importance in the developmental effort.

  14. A space telescope for infrared spectroscopy of earth-like planets

    NASA Technical Reports Server (NTRS)

    Angel, J. R. P.; Cheng, A. Y. S.; Woolf, N. J.

    1986-01-01

    It is shown here that a space telescope of 16 m diameter, apodized in a new way, could image and measure oxygen n in the thermal infrared spectral of earthlike planets up to 4 pc away. The problems of visible light imaging for this case are discussed, and it is argued that imaging the thermal emission, with greatly reduced requirements for gain and hence surface accuracy, is preferable. The requirements for such imaging are discussed, including the apodization solution.

  15. Mechanical cooler system for the next-generation infrared space telescope SPICA

    NASA Astrophysics Data System (ADS)

    Shinozaki, Keisuke; Ogawa, Hiroyuki; Nakagawa, Takao; Sato, Yoichi; Sugita, Hiroyuki; Yamawaki, Toshihiko; Mizutani, Tadahito; Matsuhara, Hideo; Kawada, Mitsunobu; Okabayashi, Akinobu; Tsunematsu, Shoji; Narasaki, Katsuhiro; Shibai, Hiroshi

    2016-07-01

    The Space Infrared Telescope for Cosmology and Astrophysics (SPICA) is a pre-project of JAXA in collaboration with ESA to be launched in the 2020s. The SPICA mission is to be launched into a halo orbit around the second Lagrangian point in the Sun-Earth system, which allows us to use effective radiant cooling in combination with a mechanical cooling system in order to cool a 2.5m-class large IR telescope below 8K. Recently, a new system design in particular thermal structure of the payload module has been studied by considering the technical feasibility of a cryogenic cooled telescope within current constraints of the mission in the CDF (Concurrent Design Facility) study of ESA/ESTEC. Then, the thermal design of the mechanical cooler system, for which the Japanese side is responsible, has been examined based on the CDF study and the feasible solution giving a proper margin has been obtained. As a baseline, 4K / 1K-class Joule-Thomson coolers are used to cool the telescope and thermal interface for Focal Plane Instruments (FPIs). Additionally, two sets of double stirling coolers (2STs) are used to cool the Telescope shield. In this design, nominal operation of FPIs can be kept when one mechanical cooler is in failure.

  16. The balloon experimental twin telescope for infrared interferometry (BETTII): optical design

    NASA Astrophysics Data System (ADS)

    Veach, Todd J.; Rinehart, Stephen A.; Mentzell, John E.; Silverberg, Robert F.; Fixsen, Dale J.; Rizzo, Maxime J.; Dhabal, Arnab; Gibbons, Caitlin E.; Benford, Dominic J.

    2014-07-01

    Here we present the optical and limited cryogenic design for The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII), an 8-meter far-infrared interferometer designed to fly on a high-altitude scientific balloon. The optical design is separated into warm and cold optics with the cold optics further separated into the far-infrared (FIR) (30-90 microns) and near-infrared (NIR) (1-3 microns). The warm optics are comprised of the twin siderostats, twin telescopes, K-mirror, and warm delay line. The cold optics are comprised of the cold delay line and the transfer optics to the FIR science detector array and the NIR steering array. The field of view of the interferometer is 2', with a wavelength range of 30-90 microns, 0.5" spectral resolution at 40 microns, R~200 spectral resolution, and 1.5" pointing stability. We also present the design of the cryogenic system necessary for operation of the NIR and FIR detectors. The cryogenic system consists of a `Buffered He-7' type cryogenic cooler providing a cold stage base temperature of < 280mK and 10 micro-Watts of heat lift and a custom in-house designed dewar that nominally provides sufficient hold time for the duration of the BETTII flight (24 hours).

  17. 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.

  18. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): High Angular Resolution Astronomy at Far-Infrared Wavelengths

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.

    2008-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe, and observations with Spitzer, the upcoming Herschel mission. and SOFIA will continue to provide exciting new discoveries. The comparatively low spatial resolution of these missions, however. is insufficient to resolve the physical scales on which mid- to far-infrared emission arises, resulting in source and structure ambiguities that limit our ability to answer key science questions. Interferometry enables high angular resolution at these wavelengths. We have proposed a new high altitude balloon experiment, the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). High altitude operation makes far-infrared (30- 300micron) observations possible, and BETTII's 8-meter baseline provides unprecedented angular resolution (-0.5 arcsec) in this band. BETTII will use a double- Fourier instrument to simultaneously obtain both spatial and spectral informatioT. he spatially resolved spectroscopy provided by BETTII will address key questions about the nature of disks in young cluster stars and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the groundwork for future space interferometers.

  19. Infrared Telescope Facility's Spectrograph Observations of Human-Made Space Objects

    NASA Technical Reports Server (NTRS)

    Abercromby, K.; Buckalew, B.; Abell, P.; Cowardin, H.

    2015-01-01

    Presented here are the results of the Infrared Telescope Facility (IRTF) spectral observations of human-made space objects taken from 2006 to 2008. The data collected using the SpeX infrared spectrograph cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 20 different orbiting objects at or near the geosynchronous (GEO) regime. Four of the objects were controlled spacecraft, seven were non-controlled spacecraft, five were rocket bodies, and the final four were cataloged as debris pieces. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials, thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons, silicon, and thermal emission. The spacecraft, both the controlled and non-controlled, show distinct features due to the presence of solar panels, whereas the rocket bodies do not. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give excellent indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. However, based on the current state of the comparison between the observations and the laboratory data, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft, rocket bodies, or debris.

  20. Technology gap assessment for a future large-aperture ultraviolet-optical-infrared space telescope

    NASA Astrophysics Data System (ADS)

    Bolcar, Matthew R.; Balasubramanian, Kunjithapatham; Crooke, Julie; Feinberg, Lee; Quijada, Manuel; Rauscher, Bernard J.; Redding, David; Rioux, Norman; Shaklan, Stuart; Stahl, H. Philip; Stahle, Carl M.; Thronson, Harley

    2016-10-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) team identified five key technology areas to enable candidate architectures for a future large-aperture ultraviolet/optical/infrared (LUVOIR) space observatory envisioned by the NASA Astrophysics 30-year roadmap, "Enduring Quests, Daring Visions." The science goals of ATLAST address a broad range of astrophysical questions from early galaxy and star formation to the processes that contributed to the formation of life on Earth, combining general astrophysics with direct-imaging and spectroscopy of habitable exoplanets. The key technology areas are internal coronagraphs, starshades (or external occulters), ultra-stable large-aperture telescope systems, detectors, and mirror coatings. For each technology area, we define best estimates of required capabilities, current state-of-the-art performance, and current technology readiness level (TRL), thus identifying the current technology gap. We also report on current, planned, or recommended efforts to develop each technology to TRL 5.

  1. The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

    NASA Technical Reports Server (NTRS)

    Wiseman, Jennifer

    2010-01-01

    The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

  2. Development of a Shuttle Infrared Telescope Facility /SIRTF/ fine guidance sensor

    NASA Technical Reports Server (NTRS)

    Salomon, P. M.; Glavich, T. A.; Goss, W. C.; Lorell, K. R.

    1981-01-01

    Fine guidance technology development for the Shuttle Infrared Telescope Facility (SIRTF) centers upon the use of a single multiple-star-tracking sensor to provide the position information necessary to produce three-axis attitude control signals for precision payload pointing. The effort described in this paper is concerned with the development of a fine guidance sensor that employs a high-density charge-coupled imaging device for producing position information signals by using star fields. Multiple star position information produces three-axis position error signals that are used to update inertial reference gyros. The sensor employs advanced position interpolation algorithms to enhance field-of-view resolution and to correct for optical aberrations inherent in spatially chopped star images resulting from the telescope's movable secondary mirror. Operation of the sensor is under the control of a high-performance microcomputer that provides both autonomy and flexibility in a guidance application.

  3. 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.

  4. A balloon-borne 102-cm telescope for far-infrared astronomy

    NASA Astrophysics Data System (ADS)

    Fazio, Giovanni G.

    1990-12-01

    In the early 1970's, the Smithsonian Astrophysical Observatory and the University of Arizona engaged in a cooperative program to develop a balloon-borne 102-cm telescope capable of carrying out far infrared (40 to 250 micron) observations of astronomical interest above the earth's atmosphere. Since 1972, the telescope has flown and successfully recovered a total of nineteen times. Thirteen of the flights produced high-quality astronomical data, resulting in more than 92.5 hours of photometric and spectroscopic observations of numerous objects, such as H 2 regions, dark clouds, molecular clouds, a planetary nebula, a galaxy, the galactic center, the planets, and an asteroid. From the launch site in Palestine, Texas, sources as far south as -50 degrees declination were observed. The balloon-borne telescope was one of the most sensitive instruments ever used for observation in the far infrared region of the spectrum. It was most productive in producing high resolution maps of large areas (typically square degrees) centered on known H 2 regions, molecular clouds, and dark cloud complexes. In many cases, these scans produced the first far infrared maps of these regions, and many new sources were discovered. The results have led to a better understanding of the distribution of gas and dust in these regions, the evolution of H 2 regions, and the processes of star formation in giant molecular clouds. The following topics are presented: (1) the focal plane instrumentation; (2) the history and flight record; (3) scientific results and publications; (4) eduational aspects; and (5) future planes.

  5. Precision Pointing for the Wide-Field Infrared Survey Telescope (WFIRST)

    NASA Technical Reports Server (NTRS)

    Stoneking, Eric; Hsu, Oscar; Welter, Gary

    2017-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission, scheduled for a mid-2020's launch, is currently in its definition phase. The mission is designed to investigate essential questions in the areas of dark energy, exoplanets, and infrared astrophysics. WFIRST will use a 2.4-meter primary telescope (same size as the Hubble Space Telescope's primary mirror) and two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). In order to ad-dress the critical science requirements, the WFIRST mission will conduct large-scale surveys of the infrared sky, requiring both agility and precision pointing (11.6 milli-arcsec stability, 14 milli-arcsec jitter). This paper describes some of the challenges this mission profile presents to the GNC subsystem, and some of the design elements chosen to accommodate those challenges. The high-galactic-latitude survey is characterized by 3-minute observations separated by slews ranging from 0.025 deg to 0.8 deg. The need for observation efficiency drives the slew and settle process to be as rapid as possible. A description of the shaped slew profile chosen to minimize excitation of structural oscillation, and the handoff from star tracker-gyro control to fine guidance sensor control is detailed. Also presented is the fine guidance sensor (FGS), which is integral with the primary instrument (WFI). The FGS is capable of tracking up to 18 guide stars, enabling robust FGS acquisition and precision pointing. To avoid excitation of observatory structural jitter, reaction wheel speeds are operationally maintained within set limits. In addition, the wheel balance law is designed to maintain 1-Hz separation between the wheel speeds to avoid reinforcing jitter excitation at any particular frequency. The wheel balance law and operational implications are described. Finally, the candidate GNC hardware suite needed to meet the requirements of the mission is presented.

  6. Precision Pointing for the Wide-Field Infrared Survey Telescope(WFIRST)

    NASA Technical Reports Server (NTRS)

    Stoneking, Eric T.; Hsu, Oscar C.; Welter, Gary

    2017-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission, scheduled for a mid-2020's launch, is currently in its definition phase. The mission is designed to investigate essential questions in the areas of dark energy, exoplanets, and infrared astrophysics. WFIRST will use a 2.4-meter primary telescope (same size as the Hubble Space Telescope's primary mirror) and two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). In order to address the critical science requirements, the WFIRST mission will conduct large-scale surveys of the infrared sky, requiring both agility and precision pointing (11.6 milli-arcsec stability, 14 milli-arcsec jitter). This paper describes some of the challenges this mission profile presents to the Guidance, Navigation, and Control (GNC) subsystem, and some of the design elements chosen to accommodate those challenges. The high-galactic-latitude survey is characterized by 3-minute observations separated by slews ranging from 0.025 deg to 0.8 deg. The need for observation efficiency drives the slew and settle process to be as rapid as possible. A description of the shaped slew profile chosen to minimize excitation of structural oscillation, and the handoff from star tracker-gyro control to fine guidance sensor control is detailed. Also presented is the fine guidance sensor (FGS), which is integral with the primary instrument (WFI). The FGS is capable of tracking up to 18 guide stars, enabling robust FGS acquisition and precision pointing. To avoid excitation of observatory structural jitter, reaction wheel speeds are operationally maintained within set limits. In addition, the wheel balance law is designed to maintain 1-Hz separation between the wheel speeds to avoid reinforcing jitter excitation at any particular frequency. The wheel balance law and operational implications are described. Finally, the candidate GNC hardware suite needed to meet the requirements of the mission is presented.

  7. A balloon-borne 102-cm telescope for far-infrared astronomy

    NASA Technical Reports Server (NTRS)

    Fazio, Giovanni G.

    1990-01-01

    In the early 1970's, the Smithsonian Astrophysical Observatory and the University of Arizona engaged in a cooperative program to develop a balloon-borne 102-cm telescope capable of carrying out far infrared (40 to 250 micron) observations of astronomical interest above the earth's atmosphere. Since 1972, the telescope has flown and successfully recovered a total of nineteen times. Thirteen of the flights produced high-quality astronomical data, resulting in more than 92.5 hours of photometric and spectroscopic observations of numerous objects, such as H 2 regions, dark clouds, molecular clouds, a planetary nebula, a galaxy, the galactic center, the planets, and an asteroid. From the launch site in Palestine, Texas, sources as far south as -50 degrees declination were observed. The balloon-borne telescope was one of the most sensitive instruments ever used for observation in the far infrared region of the spectrum. It was most productive in producing high resolution maps of large areas (typically square degrees) centered on known H 2 regions, molecular clouds, and dark cloud complexes. In many cases, these scans produced the first far infrared maps of these regions, and many new sources were discovered. The results have led to a better understanding of the distribution of gas and dust in these regions, the evolution of H 2 regions, and the processes of star formation in giant molecular clouds. The following topics are presented: (1) the focal plane instrumentation; (2) the history and flight record; (3) scientific results and publications; (4) eduational aspects; and (5) future planes.

  8. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): Spatially Resolved Spectroscopy in the Far-Infrared

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2009-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe, and observations with Spitzer, the upcoming Herschel mission, and SOFIA will continue to provide exciting new discoveries. The relatively low angular resolution of these missions, however, is insufficient to resolve the physical scale on which mid-to far-infrared emission arises, resulting in source and structure ambiguities that limit our ability to answer key science questions. Interferometry enables high angular resolution at these wavelengths - a powerful tool for scientific discovery. We will build the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII), an eight-meter baseline Michelson stellar interferometer to fly on a high-altitude balloon. BETTII's spectral-spatial capability, provided by an instrument using double-Fourier techniques, will address key questions about the nature of disks in young star clusters and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the technological groundwork for future space interferometers and for suborbital programs optimized for studying extrasolar planets.

  9. Balloon-borne three-meter telescope for far-infrared and submillimeter astronomy

    NASA Technical Reports Server (NTRS)

    Fazio, Giovanni G.; Hoffmann, William F.; Harper, Doyal A.

    1988-01-01

    The scientific objectives, engineering analysis and design, results of technology development, and focal-plane instrumentation for a two-meter balloon-borne telescope for far-infrared and submillimeter astronomy are presented. The unique capabilities of balloon-borne observations are discussed. A program summary emphasizes the development of the two-meter design. The relationship of the Large Deployable Reflector (LDR) is also discussed. Detailed treatment is given to scientific objectives, gondola design, the mirror development program, experiment accommodations, ground support equipment requirements, NSBF design drivers and payload support requirements, the implementation phase summary development plan, and a comparison of three-meter and two-meter gondola concepts.

  10. Detector Arrays for the James Webb Space Telescope Near-Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Alexander, David; Brambora, Clifford K.; Derro, Rebecca; Engler, Chuck; Fox, Ori; Garrison, Matthew B.; Henegar, Greg; Hill, robert J.; Johnson, Thomas; Lindler, Don J.; Manthripragada, Sridhar S.; Marshall, Ceryl; Mott, Brent; Parr, Thomas M.; Roher, Wayne D.; Shakoorzadeh, Kamdin B.; Smith, Miles; Waczynski, Augustyn; Wen, Yiting; Wilson, Donna; Xia-Serafino, Wei

    2007-01-01

    The James Webb Space Telescope's (JWST) Near Infrared Spectrograph (NIRSpec) incorporates two 5 micron cutoff (lambda(sub co) = 5 microns) 2048x2048 pixel Teledyne HgCdTe HAWAII-2RG sensor chip assemblies. These detector arrays, and the two Teledyne SIDECAR application specific integrated circuits that control them, are operated in space at T approx. 37 K. In this article, we provide a brief introduction to NIRSpec, its detector subsystem (DS), detector readout in the space radiation environment, and present a snapshot of the developmental status of the NIRSpec DS as integration and testing of the engineering test unit begins.

  11. CISCO: Cooled Infrared Spectrograph and Camera for OHS on the Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Motohara, Kentaro; Iwamuro, Fumihide; Maihara, Toshinori; Oya, Shin; Tsukamoto, Hiroyuki; Imanishi, Masatoshi; Terada, Hiroshi; Goto, Miwa; Iwai, Jun'ichi; Tanabe, Hirohisa; Hata, Ryuji; Taguchi, Tomoyuki; Harashima, Takashi

    2002-04-01

    This paper describes a Cooled Infrared Spectrograph and Camera for OHS (CISCO), mounted on the Nasmyth focus of the Subaru telescope. It is primarily designed as a back-end camera of the OH-Airglow Suppressor (OHS), and is also used as an independent, general-purpose near-infrared camera/spectrograph. CISCO is based on a single 1024 × 1024 format HgCdTe HAWAII array detector, and is capable of either wide-field imaging of 1'.8 × 1'.8 field-of-view or low-resolution spectroscopy from 0.9 to 2.4 μm. The limiting magnitudes measured during test observations were found to be J=23.5 mag and K' = 22.4 mag (imaging, 1" aperture, S/N = 5, 1hr exposure).

  12. Infrared photometry with 'wall-eyed' pointing at the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Spalding, Eckhart; Skemer, Andrew; Hinz, Philip M.; Hill, John M.

    2016-08-01

    The brightness and variability of the atmosphere in the thermal infrared poses obstacles to precision photometry measurements. The need to remove atmospheric effects calls for the use of a comparison star, but it is usually impossible to fit both science and comparison targets on current long-wavelength (>2 μm) detectors. We present a new pointing mode at the Large Binocular Telescope, which has twin 8.4-m primary mirrors that can be pointed up to 2 arcminutes apart and allow the placement of both targets on a small-field infrared detector. We present an observation of the primary transit of an exoplanet in front of its host star, and use it to provide preliminary constraints on the attainable photometric precision.

  13. Detectors for the James Webb Space Telescope Near-Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Figer, Donald F.; Regan, Michael W.; Boeker, Torsten; Garnett, James; Hill, Robert J.; Bagnasco, Georgio; Balleza, Jesus; Barney, Richard; Bergeron, Louis E.

    2004-01-01

    The Near-Infrared Spectrograph (NIRSpec) is the James Webb Space Telescope's primary near-infrared spectrograph. NASA is providing the NIRSpec detector subsystem, which consists of the focal plane array, focal plane electronics, cable harnesses, and software. The focal plane array comprises two closely-butted lambda (sub co) approximately 5 micrometer Rockwell HAWAII- 2RG sensor chip assemblies. After briefly describing the NIRSpec instrument, we summarize some of the driving requirements for the detector subsystem, discuss the baseline architecture (and alternatives), and presents some recent detector test results including a description of a newly identified noise component that we have found in some archival JWST test data. We dub this new noise component, which appears to be similar to classical two-state popcorn noise in many aspects, "popcorn mesa noise." We close with the current status of the detector subsystem development effort.

  14. A Compact Infrared Space Telescope MIRIS and its Preliminary Observational Results

    NASA Astrophysics Data System (ADS)

    Han, Wonyong; Pyo, Jeonghyun; Kim, Il-Joong; Lee, Dae-Hee; Jeong, Woong-Seob; Moon, Bongkon; Park, Youngsik; Park, Sung-Joon; Lee, Dukhang; Park, Won-Kee; Ko, Kyeongyeon; Kim, Min Gyu; Nam, Uk-Won; Park, Hong-Young; Lee, Hyung Mok; Matsumoto, Toshio

    2015-08-01

    The first Korean infrared space telescope MIRIS (Milti-purpose InfraRed Imaging System) was successfully launched in November 2013, as the main payload of Korean STSAT-3 (Science and Technology Satellite-3). After the initial on-orbit operation for verification, the observations are made with MIRIS for the fluctuation of Cosmic Infrared Background (CIB) and the Galactic Plane survey. For the study of near-infrared background, MIRIS surveyed large areas (> 10° x 10°) around the pole regions: the north ecliptic pole (NEP), the north and south Galactic poles (NGP, SGP), while the NEP region is continually monitored for the instrumental calibration and the zodiacal light study. In addition, the Paschen-α Galactic plane survey has been made with two narrow-band filters (at 1.88 μm and 1.84+1.92 μm) for the study of warm interstellar medium. We plan to continue surveying the entire galactic plane with the latitude of ±3°, and expect to be completed by 2015. The data are still under the stage of reduction and analysis, and guest observations are on-going. We present some of the preliminary results.

  15. Scientific and Mission Requirements of Next-generation Space Infrared Space Telescope SPICA

    NASA Astrophysics Data System (ADS)

    Matsuhara, Hideo; Nakagawa, Takao; Ichikawa, Takashi; Takami, Michihiro; Sakon, Itsuki

    SPICA (Space Infrared Telescope for Cosmology Astrophysics) is a next-generation space tele-scope for mid-and far-infrared astronomy, based on the heritage of AKARI, Spitzer, and Her-schel, Here we introduce Mission Requirement Document (MRD), where scientific and mission requirement of SPICA are described. The MRD clarifies the objectives of the SPICA mission. These objectives are more concretely expressed by various scientific targets, and based on these targets, the mission requirements, such as required specifications of the mission instrumenta-tions, scientific operations etc. are defined. Also the success criteria, by which the evaluation of the mission achievement will be addressed, are clearly described. The mission requirements described here will give the baseline of the study of the system requirements. In the future, The MRD will also be used to confirm the development status, system performance, and operational results on orbit etc. are well in-line with the mission requirements. To summarize, the most important mission requirement of SPICA is to realize a large, mono-lithic (not segmented) 3-m class or larger mirror cooled down below 6K, in order to perform extremely deep imaging and spectroscopy at 5-210µm.

  16. Towards Background-Limited Kinetic Inductance Detectors for a Cryogenic Far-Infrared Space Telescope

    NASA Astrophysics Data System (ADS)

    Fyhrie, A.; Glenn, J.; Wheeler, J.; Day, P.; Eom, B. H.; Leduc, H.; Skrutskie, M.

    2016-08-01

    Arrays of tens of thousands of sensitive far-infrared detectors coupled to a cryogenic 4-6 m class orbital telescope are needed to trace the assembly of galaxies over cosmic time. The sensitivity of a 4 Kelvin telescope observing in the far-infrared (30-300 \\upmu m) would be limited by zodiacal light and Galactic interstellar dust emission, and require broadband detector noise equivalent powers (NEPs) in the range of 3× 10^{-19} W/√{Hz}. We are fabricating and testing 96 element arrays of lumped-element kinetic inductance detectors (LEKIDs) designed to reach NEPs near this level in a low-background laboratory environment. The LEKIDs are fabricated with aluminum: the low normal-state resistivity of Al permits the use of very thin wire-grid absorber lines (150 nm) for efficient absorption of radiation, while the small volumes enable high sensitivities because quasiparticle densities are high. Such narrow absorption lines present a fabrication challenge, but we deposit TiN atop the Al to increase the robustness of the detectors and achieve a 95 % yield. We present the design of these Al/TiN bilayer LEKIDs and preliminary sensitivity measurements at 350 \\upmu m optically loaded by cold blackbody radiation.

  17. TALC: a new deployable concept for a 20m far-infrared space telescope

    NASA Astrophysics Data System (ADS)

    Durand, Gilles; Sauvage, Marc; Bonnet, Aymeric; Rodriguez, Louis; Ronayette, Samuel; Chanial, Pierre; Scola, Loris; Révéret, Vincent; Aussel, Hervé; Carty, Michael; Durand, Matthis; Durand, Lancelot; Tremblin, Pascal; Pantin, Eric; Berthe, Michel; Martignac, Jérôme; Motte, Frédérique; Talvard, Michel; Minier, Vincent; Bultel, Pascal

    2014-08-01

    TALC, Thin Aperture Light Collector is a 20 m space observatory project exploring some unconventional optical solutions (between the single dish and the interferometer) allowing the resolving power of a classical 27 m telescope. With TALC, the principle is to remove the central part of the prime mirror dish, cut the remaining ring into 24 sectors and store them on top of one-another. The aim of this far infrared telescope is to explore the 600 μm to 100 μm region. With this approach we have shown that we can store a ring-telescope of outer diameter 20m and ring thickness of 3m inside the fairing of Ariane 5 or Ariane 6. The general structure is the one of a bicycle wheel, whereas the inner sides of the segments are in compression to each other and play the rule of a rim. The segments are linked to each other using a pantograph scissor system that let the segments extend from a pile of dishes to a parabolic ring keeping high stiffness at all time during the deployment. The inner corners of the segments are linked to a central axis using spokes as in a bicycle wheel. The secondary mirror and the instrument box are built as a solid unit fixed at the extremity of the main axis. The tensegrity analysis of this structure shows a very high stiffness to mass ratio, resulting into 3 Hz Eigen frequency. The segments will consist of two composite skins and honeycomb CFRP structure build by replica process. Solid segments will be compared to deformable segments using the controlled shear of the rear surface. The adjustment of the length of the spikes and the relative position of the side of neighbor segments let control the phasing of the entire primary mirror. The telescope is cooled by natural radiation. It is protected from sun radiation by a large inflatable solar screen, loosely linked to the telescope. The orientation is performed by inertia-wheels. This telescope carries a wide field bolometer camera using cryocooler at 0.3K as one of the main instruments. This

  18. 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.

  19. High-performance wobbling subreflector for the Millimetre and Infrared Testa Grigia Observatory 2.6-m telescope

    NASA Astrophysics Data System (ADS)

    Mainella, Gianni; de Bernardis, Paolo; de Petris, Marco; Mandiello, Alfonso; Perciballi, Maurizio; Romeo, Gianni

    1996-05-01

    The Millimetre and Infrared Testa Grigia Observatory 2.6-m Cassegrain telescope has been designed to allow high-sensitivity observations in the millimeter spectral range. For this purpose, in order to reduce unwanted contributions from local foregrounds, we adopted a sky-chopping technique, by wobbling the telescope subreflector. We describe the design and performance of the wobbling system, which can endure external forced two and three fields square-wave modulation and includes features such as high frequency, high amplitude, high duty cycle, low microphonics, and high stability. millimeter-wave telescope.

  20. ESA switches its infrared space telescope off and will clean its orbit

    NASA Astrophysics Data System (ADS)

    1998-05-01

    Controllers at the ESA ground station at Villafranca (Madrid, Spain) witnessed the definitive end for the telescope but they didn't have to press any 'red button' or the like. The instructions for the switch off had already been introduced into ISO's computer earlier. ISO's last month of life was used to gather as much technical data as possible. Various software and hardware systems that, due to the superb performance of the spacecraft, did not have to be used during the operational phase were subjected to detailed tests. Results from these tests will benefit future ESA missions, such as XMM and Integral, which use some of the same components, such as the Star Trackers guiding the spacecraft. Also, ISO's farewell included a further last gift for the astronomers. A few of the detectors in the Short Wavelength Spectrometer (SWS), one of the four instruments on-board the satellite, could still be used after exhaustion of the liquid helium. In anticipation of this opportunity, a special scientific programme has been prepared and was interleaved with the technology tests. Some 150 extra hours were used to measure nearly 300 stars at wavelengths between 2.4 and 4 microns enabling astronomers to make a detailed spectral classification. In fact, ISO continued to give scientific surprises to the very sad end. ISO's 'last light' observation - taken with the SWS instrument just before midnight on May 10 - was of emission lined from hydrogen in hot supergiant star (eta Canis Majoris). The preliminary results show that this star, supposed to be ordinary, is probably surrounded by a disk of matter. Commenting on the satellite switch off, ESA's Director of Science, Roger Bonnet, said "ISO has allowed us to gain the first clear view of the universe at infrared wavelengths. A great amount of work still awaits us to interpret all ISO's exciting discoveries. We will miss ISO, of course - new answers always bring new questions and the wish for yet more knowledge; that is why ESA is

  1. Optical characterisation and analysis of multi-mode pixels for use in future far infrared telescopes

    NASA Astrophysics Data System (ADS)

    McCarthy, Darragh; Trappe, Neil; Murphy, J. Anthony; Doherty, Stephen; Gradziel, Marcin; O'Sullivan, Créidhe; Audley, Michael D.; de Lange, Gert; van der Vorst, Maarten

    2016-07-01

    , to be proposed as an ESA M5 mission. It is planned for this mission to be launched on board the proposed SPICA (SPace Infrared telescope for Cosmology and Astrophysics) mission, in collaboration with JAXA. SAFARI is planned to operate in the 1.5-10 THz band, focussing on the formation and evolution of galaxies, stars and planetary systems. The pixel that drove the development of the techniques presented in this paper is typical of one option that could be implemented in the SAFARI focal plane, and so the ability to accurately understand and characterise such pixels is critical in the design phase of the next generation of far IR telescopes.

  2. A dc-coupled, high sensitivity bolometric detector system for the Infrared Telescope in Space

    NASA Technical Reports Server (NTRS)

    Devlin, M.; Lange, A. E.; Wilbanks, T.; Sato, S.

    1993-01-01

    We report the performance of an ac bridge readout system that has been developed for use on the Infrared Telescope in Space which is scheduled for launch in 1994. The ac bridge readout provides excellent dc stability enabling observing strategies well-suited to space-borne observations. The ability to modulate the optical signal slowly allows the use of new, highly sensitive, long time-constant bolometers. At 300 mK, the bolometers have an electrical noise equivalent power of 3 x 10 exp -17 W/sq rt Hz. The total noise of the differential signal, including amplifier noise, is less than 8 x 10 exp -17 W/sq rt Hz at frequencies as low as 35 mHz.

  3. Balloon-borne three-meter telescope for far-infrared and submillimeter astronomy

    NASA Technical Reports Server (NTRS)

    Fazio, G. G.

    1985-01-01

    This is the second Semiannual Report submitted under Grant NAGW-509 for the development of a Balloon-Borne Three-Meter Telescope for Far-Infrared and Submillimeter Astronomy. It covers the period 1 March 1984 through 31 August 1984. This grant covers work at the Smithsonian Astrophysical Observatory (SAO), University of Arizona (UA) and the University of Chicago (UC). SAO is responsible for program management, the gondola structure including the attitude control and aspect systems, mechanical systems, and telemetry and command systems; the UA is responsible for optics design and fabrication; the UC is responsible for determining provisions for focal-plane instrumentation. SAO and the UA share responsibility for the ground support data and control computer.

  4. Science yield estimate with the Wide-Field Infrared Survey Telescope coronagraph

    NASA Astrophysics Data System (ADS)

    Traub, Wesley A.; Breckinridge, James; Greene, Thomas P.; Guyon, Olivier; Jeremy Kasdin, N.; Macintosh, Bruce

    2016-01-01

    The coronagraph instrument (CGI) on the Wide-Field Infrared Survey Telescope will directly image and spectrally characterize planets and circumstellar disks around nearby stars. Here we estimate the expected science yield of the CGI for known radial-velocity (RV) planets and potential circumstellar disks. The science return is estimated for three types of coronagraphs: the hybrid Lyot and shaped pupil are the currently planned designs, and the phase-induced amplitude apodizing complex mask coronagraph is the backup design. We compare the potential performance of each type for imaging as well as spectroscopy. We find that the RV targets can be imaged in sufficient numbers to produce substantial advances in the science of nearby exoplanets. To illustrate the potential for circumstellar disk detections, we estimate the brightness of zodiacal-type disks, which could be detected simultaneously during RV planet observations.

  5. Robust determination of optical path difference: fringe tracking at the infrared optical telescope array interferometer.

    PubMed

    Pedretti, Ettore; Traub, Wesley A; Monnier, John D; Millan-Gabet, Rafael; Carleton, Nathaniel P; Schloerb, F Peter; Brewer, Michael K; Berger, Jean-Philippe; Lacasse, Marc G; Ragland, Sam

    2005-09-01

    We describe the fringe-packet tracking system used to equalize the optical path lengths at the Infrared Optical Telescope Array interferometer. The measurement of closure phases requires obtaining fringes on three baselines simultaneously. This is accomplished by use of an algorithm based on double Fourier interferometry for obtaining the wavelength-dependent phase of the fringes and a group-delay tracking algorithm for determining the position of the fringe packet. A comparison of data acquired with and without the fringe-packet tracker shows a factor of approximately 3 reduction of the error in the closure-phase measurement. The fringe-packet tracker has been able so far to track fringes with signal-to-noise ratios as low as 1.8 for stars as faint as mH = 7.0.

  6. First Light Infrared Observations with the 1.6 Meter Solar Telescope in Big Bear: Origins of Space Weather Telescope

    DTIC Science & Technology

    2012-08-16

    later transported toward the corona . 2)We investigated properties of magnetic fields in nearly 400 solar active regions. Time profiles of...1.6 Meter Solar Telescope in Big Bear: Origins of Space Weather Telescope. 5a. CONTRACT NUMBER FA9550-09-1-0655 5b. GRANT NUMBER 5c. PROGRAM...STATEMENT 13. SUPPLEMENTARY NOTES 14. ABSTRACT In early 2009 at Big Bear Solar Observatory (BBSO), first light science observations were made

  7. Optics of Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): delay lines and alignment

    NASA Astrophysics Data System (ADS)

    Dhabal, Arnab; Rinehart, Stephen A.; Rizzo, Maxime J.; Mundy, Lee

    2016-07-01

    We present the optics of Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) as it gets ready for launch. BETTII is an 8-meter baseline far-infrared (30-90 μm) interferometer mission with capabilities of spatially resolved spectroscopy aimed at studying star formation and galaxy evolution. The instrument collects light from its two arms, makes them interfere, divides them into two science channels (30-50 μm and 60-90 μm), and focuses them onto the detectors. It also separates out the NIR light (1-2.5 μm) and uses it for tip-tilt corrections of the telescope pointing. Currently, all the optical elements have been fabricated, heat treated, coated appropriately and are mounted on their respective assemblies. We are presenting the optical design challenges for such a balloon borne spatio- spectral interferometer, and discuss how they have been mitigated. The warm and cold delay lines are an important part of this optics train. The warm delay line corrects for path length differences between the left and the right arm due to balloon pendulation, while the cold delay line is aimed at introducing a systematic path length difference, thereby generating our interferograms from where we can derive information about the spectra. The details of their design and the results of the testing of these opto-mechanical parts are also discussed. The sensitivities of different optical elements on the interferograms produced have been determined with the help of simulations using FRED software package. Accordingly, an alignment plan is drawn up which makes use of a laser tracker, a CMM, theodolites and a LUPI interferometer.

  8. Near-infrared detection of WD 0806-661 B with the Hubble space telescope

    SciTech Connect

    Luhman, K. L.; Esplin, T. L.; Morley, C. V.; Burgasser, A. J.; Bochanski, J. J.

    2014-10-10

    WD 0806-661 B is one of the coldest known brown dwarfs (T {sub eff} = 300-345 K) based on previous mid-infrared photometry from the Spitzer Space Telescope. In addition, it is a benchmark for testing theoretical models of brown dwarfs because its age and distance are well constrained via its primary star (2 ± 0.5 Gyr, 19.2 ± 0.6 pc). We present the first near-infrared detection of this object, which has been achieved through F110W imaging (∼Y + J) with the Wide Field Camera 3 on board the Hubble Space Telescope. We measure a Vega magnitude of m {sub 110} = 25.70 ± 0.08, which implies J ∼ 25.0. When combined with the Spitzer photometry, our estimate of J helps to better define the empirical sequence of the coldest brown dwarfs in M {sub 4.5} versus J – [4.5]. The positions of WD 0806-661 B and other Y dwarfs in that diagram are best matched by the cloudy models of Burrows et al. and the cloudless models of Saumon et al., both of which employ chemical equilibrium. The calculations by Morley et al. for 50% cloud coverage differ only modestly from the data. Spectroscopy would enable a more stringent test of the models, but based on our F110W measurement, such observations are currently possible only with Hubble, and would require at least ∼10 orbits to reach a signal-to-noise ratio of ∼5.

  9. KASINICS: Near Infrared Camera System for the BOAO 1.8m Telescope

    NASA Astrophysics Data System (ADS)

    Moon, Bongkon; Jin, Ho; Yuk, In-Soo; Lee, Sungho; Nam, Uk-Won; Cha, Sang-Mok; Cho, Seoung-Hyun; Kyeong, Jae-Mann; Park, Youngsik; Mock, Seungwon; Han, Jeong-Yeol; Lee, Dea-Hee; Park, Jang-Hyun; Han, Wonyong; Pak, Soojong; Kim, Geon-Hee; Kim, Yong Ha

    2008-08-01

    We developed Korea Astronomy and Space science Institute (KASI) Near Infrared Camera System (KASINICS) to be installed on the 1.8m telescope of Bohyunsan Optical Astronomy Observatory (BOAO) in Korea. We use a 512×512 InSb array (Aladdin III Quadrant, Raytheon Co.) to enable L band observations as well as J, H, and KS bands. The field-of-view of the array is 3.3'× 3.3' with a resolution of 0.39''/ pixel. We adopt an Offner relay optical system, which provides a cold stop to eliminate thermal background emission from the telescope structures. Most parts of the camera, including the mirrors, were manufactured from the same ingot of aluminum alloy to ensure a homologous contraction from room temperature to 80K. We also developed a readout electronics system for the array detector. Based on preliminary results from test observations, the limiting magnitudes are J = 17.6, H = 17.5, KS = 16.1, and L(narrow) = 10.0mag at a signal-to-noise ratio of 10 for an integration time of 100s.

  10. From Single Pixels to Many Megapixels: Progress in Astronomical Infrared Imaging from Space-borne Telescopes

    NASA Astrophysics Data System (ADS)

    Pipher, Judith

    2017-01-01

    In the 1960s, rocket infrared astronomy was in its infancy. The Cornell group planned a succession of rocket launches of a small cryogenically cooled telescope above much of the atmosphere. Cornell graduate students were tasked with hand-making single pixel detectors for the focal plane at wavelengths ranging from ~5 microns to just short of 1 mm. “Images” could only be constructed from scans of objects such as HII regions/giant molecular clouds, the galactic center, and of diffuse radiation from the various IR backgrounds. IRAS and COBE, followed by the KAO utilized ever more sensitive single IR detectors, and revolutionized our understanding of the Universe. The first IR arrays came onto the scene in the early 1970s - and in 1983 several experiments for the space mission SIRTF (later named Spitzer Space Telescope following launch 20 years later) were selected, all boasting (relatively small) arrays. Europe’s ISO and Herschel also employed arrays to good advantage, as has SOFIA, and now, many-megapixel IR arrays are sufficiently well-developed for upcoming space missions.

  11. New phase compensating secondary mirrors for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Tollestrup, Eric V.; Tokunaga, Alan T.

    2010-07-01

    The NASA Infrared Telescope Facility is engaged in a long-term program to improve the image quality of the telescope. One element of the program is to minimize the static aberrations. The largest static aberration is spherical aberration, although aberrations caused by zonal polishing rings and support-pad print-through on the primary mirror are also significant. To correct these static wave front errors, a new secondary mirror is being fabricated with a custom, phase compensating surface. Since the as-built optical specifications for the IRTF mirrors have been lost, a configurable multimode instrument was fabricated for use at both the prime and Cassegrain foci to characterize the primary mirror and to measure the wave front errors at both foci. The instrument modes include a focal plane camera, a knife-edge tester, a pupil viewer, a Hartmann wave front sensor, a calibrator, and an on-axis guider. Test results from the prime focus show that the primary mirror has an incorrect conic surface and is poorly supported, which results in a fixed amount of spherical aberration and variable amounts of astigmatism, coma, and trefoil. Cassegrain focal plane results show that the original secondary mirror mount system also induces aberrations. Two new secondary mirrors have been made and at least one of the mirrors will have a custom surface, using ion beam polishing methods, to correct these static aberrations. An analysis is presently underway to determine the optimum compensating surface to be applied by ion beam polishing.

  12. Prototype secondary mirror assembly design for the space infrared telescope facility

    NASA Technical Reports Server (NTRS)

    Stier, M.; Duffy, M.; Gullapalli, S.; Rockwell, R.; Sileo, F.

    1989-01-01

    The authors describe the design of a liquid helium temperature prototype secondary mirror assembly (PSMA) under developement for the NASA Space Infrared Telescope Facility (SIRTF) program. The SIRTF secondary mirror assembly must operate below 4 K and provide highly precise two-axis dynamic tilting (chopping) in addition to the conventional functions needed by the SIRTF observatory. The PSMA design uses a fused quartz mirror kinematically attached at its center to an aluminum cruciform. The mirror/cruciform assembly is driven in tilt about its combined center of mass using a unique flexure pivot and a four-actuator control system with feedback provided by pairs of differential position sensors. The voice coil actuators are mounted on a second flexture-pivoted mass, enhancing servo system stability and isolating the telescope from vibration-induced disturbances. The mirror/cruciform and the reaction mass are attached to opposite sides of an aluminum mounting plate whose dimensional characteristics are nominally identical to those of the aluminum flexure pivot material. The mounting plate is connected to the outer housing by a six-degree-of-freedom focus and centering mechanism using pivoted actuation levers driven by lead screw/harmonic drive/stepper motor assemblies.

  13. Design of a prototype secondary mirror assembly for the Space Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Stier, Mark T.; Bolin, Kenneth N.; Duffy, Michael A.; Gullapalli, Sarma N.; Krim, Michael H.; Rockwell, Richard A.; Sileo, Francis R.

    1990-01-01

    The design of a liquid helium temperature prototype secondary mirror assembly (PSMA) under development for the NASA Space Infrared Telescope Facility (SIRTF) program is described. The SIRTF assembly must operate below 4 K and provide the functions of highly precise two-axis periodic tilting ('chopping') in addition to the conventional functions of focus and collimation adjustment. The PSMA design employs a fused quartz mirror kinematically attached at its center to an aluminum cruciform. The mirror/cruciform assembly is driven in tilt about its combined center of mass using an aluminum flexure pivot of unique design and a four-actuator control system with feedback provided by pairs of differential position sensors. The voice coil actuators are mounted on a second flexure-pivoted mass to enhance servosystem stability and isolate the telescope from vibration-induced disturbances. The mirror/cruciform and reaction mass are attached to opposite sides of an aluminum mounting plate whose position relative to the outer housing is controlled by a six-degree-of-freedom focus and centering mechanism using pivoted actuation levers driven by lead screw/harmonic drive/stepper motor assemblies.

  14. DM/LCWFC based adaptive optics system for large aperture telescopes imaging from visible to infrared waveband.

    PubMed

    Sun, Fei; Cao, Zhaoliang; Wang, Yukun; Zhang, Caihua; Zhang, Xingyun; Liu, Yong; Mu, Quanquan; Xuan, Li

    2016-11-28

    Almost all the deformable mirror (DM) based adaptive optics systems (AOSs) used on large aperture telescopes work at the infrared waveband due to the limitation of the number of actuators. To extend the imaging waveband to the visible, we propose a DM and Liquid crystal wavefront corrector (DM/LCWFC) combination AOS. The LCWFC is used to correct the high frequency aberration corresponding to the visible waveband and the aberrations of the infrared are corrected by the DM. The calculated results show that, to a 10 m telescope, DM/LCWFC AOS which contains a 1538 actuators DM and a 404 × 404 pixels LCWFC is equivalent to a DM based AOS with 4057 actuators. It indicates that the DM/LCWFC AOS is possible to work from visible to infrared for larger aperture telescopes. The simulations and laboratory experiment are performed for a 2 m telescope. The experimental results show that, after correction, near diffraction limited resolution USAF target images are obtained at the wavebands of 0.7-0.9 μm, 0.9-1.5 μm and 1.5-1.7 μm respectively. Therefore, the DM/LCWFC AOS may be used to extend imaging waveband of larger aperture telescope to the visible. It is very appropriate for the observation of spatial objects and the scientific research in astronomy.

  15. Near-Infrared Interferometric Images of the Solar System Sized Disk Surrounding the Herbig Ae/Be Star MWC 349A

    NASA Technical Reports Server (NTRS)

    Danchi, W.C.; Tuthill, P. G.; Monnier, J. D.; Fisher, Richard (Technical Monitor)

    2000-01-01

    We present images of the Herbig Ae/Be star MWC 349A at 1.65 and 2.27, and 3.08 micrometers, reconstructed from complex visibility data obtained with an aperture masking interferometric technique on the Keck I telescope. These images have an approximately elliptical shape, and are consistent with the expected shape of a nearly edge-on Keplerian disk. Visibility data were fitted with uniform ellipses with major axes 36 +/- 2, 47 +/- 2, and 62 +/- 1 mas, respectively. The axial ratio of the ellipses is approximately 0.5 +/- 0.1, and the major axis is at a position angle of 100 +/- 3 degrees, consistent with the position angle of the dark lane observed previously in the Very Large Array (VLA) radio continuum maps at 8 and 22 GHz, perpendicular to the symmetry axis of the bipolar lobes of H66(alpha) recombination line emission, and consistent with positions of the recombination line maser spots at 1.3 mm. At an assumed distance of 1.2 kpc, the linear sizes of the disk are 44 and 57 AU at 1.65 and 2.2 micrometers, respectively. The disk is the presumed source of ionized material in the bipolar outflow and ultracompact HII region around the star.

  16. New high spectral resolution spectrograph and mid-IR camera for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Tokunaga, Alan T.; Bus, Schelte J.; Connelley, Michael; Rayner, John

    2016-10-01

    The NASA Infrared Telescope Facility (IRTF) is a 3.0 m infrared telescope located at an altitude of 4.2 km near the summit of Mauna Kea on the island of Hawaii. The IRTF was established by NASA to support planetary science missions. We show new observational capabilities resulting from the completion of iSHELL, a 1-5 μm echelle spectrograph with resolving power of 70,000 using a 0.375 arcsec slit. This instrument will be commissioned starting in August 2016. The spectral grasp of iSHELL is enormous due to the cross-dispersed design and use of a 2Kx2K HgCdTe array. Raw fits files will be publicly archived, allowing for more effective use of the large amount of spectral data that will be collected. The preliminary observing manual for iSHELL, containing the instrument description, observing procedures and estimates of sensitivity can be downloaded at http://irtfweb.ifa.hawaii.edu/~ishell/iSHELL_observing_manual.pdf. This manual and instrument description papers can be downloaded at http://bit.ly/28NFiMj. We are also working to restore to service our 8-25 μm camera, MIRSI. It will be upgraded with a closed cycle cooler that will eliminate the need for liquid helium and allow continuous use of MIRSI on the telescope. This will enable a wider range of Solar System studies at mid-IR wavelengths, with particular focus on thermal observations of NEOs. The MIRSI upgrade includes plans to integrate a visible CCD camera that will provide simultaneous imaging and guiding capabilities. This visible imager will utilize similar hardware and software as the MORIS system on SpeX. The MIRSI upgrade is being done in collaboration with David Trilling (NAU) and Joseph Hora (CfA). For further information on the IRTF and its instruments including visitor instruments, see: http:// irtfweb.ifa.hawaii.edu/. We gratefully acknowledge the support of NASA contract NNH14CK55B, NASA Science Mission Directorate, and NASA grant NNX15AF81G (Trilling, Hora) for the upgrade of MIRSI.

  17. Infrared observations of the solar system in support of Large-Aperture Infrared Telescope (LARITS): Calibration. Final technical report, 1 July 1985-28 February 1989

    SciTech Connect

    Shorthill, R.W.

    1990-05-02

    The Purpose of this project was to improve the infrared calibration base for infrared detectors. Groundbased infrared measurements of solid-surfaced planetary bodies, such as asteroids, are being used for the calibration of spacecraft detectors. A limitation has been the relatively poor theoretical understanding of thermal emission from these objects. The goal was to: (1) develop a database of sources and, (2) improve or modify the thermal models for these sources to provide a calibration data base for spacecraft infrared detector systems. The technique consisted of five phases: (1) design and construct infrared detector system to be used with and without collecting optics, (2) acquire whole-disk infrared lunar data relative to a laboratory blackbody and tie them to Mars (Venus or Mercury) and Vega, (3) compare with thermophysical model of the mood and modify, (4) acquire infrared asteroid photometry, (5) compare the lunar disk photometry the asteroid calibrators using photometry and thermophysical models. The Si bolometer is calibrated without optics, attached to the portable telescope drive and Lunar disk measurement made. Next the bolometer is attached to the 90 inch telescope, Lunar scans are made and the remaining objects (planets, stars, asteroids) are measured.

  18. A Study of Planetary Nebulae using the Faint Object Infrared Camera for the SOFIA Telescope

    NASA Technical Reports Server (NTRS)

    Davis, Jessica

    2012-01-01

    A planetary nebula is formed following an intermediate-mass (1-8 solar M) star's evolution off of the main sequence; it undergoes a phase of mass loss whereby the stellar envelope is ejected and the core is converted into a white dwarf. Planetary nebulae often display complex morphologies such as waists or torii, rings, collimated jet-like outflows, and bipolar symmetry, but exactly how these features form is unclear. To study how the distribution of dust in the interstellar medium affects their morphology, we utilize the Faint Object InfraRed CAmera for the SOFIA Telescope (FORCAST) to obtain well-resolved images of four planetary nebulae--NGC 7027, NGC 6543, M2-9, and the Frosty Leo Nebula--at wavelengths where they radiate most of their energy. We retrieve mid infrared images at wavelengths ranging from 6.3 to 37.1 micron for each of our targets. IDL (Interactive Data Language) is used to perform basic analysis. We select M2-9 to investigate further; analyzing cross sections of the southern lobe reveals a slight limb brightening effect. Modeling the dust distribution within the lobes reveals that the thickness of the lobe walls is higher than anticipated, or rather than surrounding a vacuum surrounds a low density region of tenuous dust. Further analysis of this and other planetary nebulae is needed before drawing more specific conclusions.

  19. 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.

  20. 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.

  1. HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

    SciTech Connect

    Schneider, Adam C.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Wright, Edward L.; Eisenhardt, Peter R.; Skrutskie, M. F.; Griffith, Roger L.; Marsh, Kenneth A.

    2015-05-10

    We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments.

  2. 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.

  3. Study of advanced InSb arrays for SIRTF (Space Infrared Telescope Facility)

    NASA Technical Reports Server (NTRS)

    Hoffman, Alan; Feitt, Robert

    1989-01-01

    The Santa Barbara Research Center has completed a study leading to the development of advanced Indium Antimonide detector arrays for the Space Infrared Telescope Facility (SIRTF) Focal Plane Array Detector (FPAD) Subsystem of the Infrared Array Camera (IRAC) Band 1. The overall goal of the study was to perform design tradeoff studies, analysis and research to develop a Direct Readout Integrated Circuit to be hybridized to an advanced, high performance InSb detector array that would satisfy the technical requirements for Band 1 as specified in the IRAC Instrument Requirements Document (IRD), IRAC-202. The overall goal of the study was divided into both a near-term goal and a far-term goal. The near-term goal identifies current technology available that approaches, and in some cases meets the program technological goals as specified in IRAC-202. The far-term goal identifies technology development required to completely achieve SIRTF program goals. Analyses of potential detector materials indicates that InSb presently meets all Band 1 requirements and is considered to be the baseline approach due to technical maturity. The major issue with regard to photovoltaic detectors such as InSb and HgCdTe is to achieve a reduction in detector capacitance.

  4. 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

  5. Design and Status of the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): An Interferometer at the Edge of Space

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.; Barclay, Richard B.; Barry, R. K.; Benford, D. J.; Calhoun, P. C.; Fixsen, D. J.; Gorman, E. T.; Jackson, M. L.; Jhabvala, C. A.; Leisawitz, D. T.; Maher, S. F.; Mentzell, J. E.; Mundy, L. G.; Rizzo, M. J.; Silverberg, R. F.; Staguhn, J. G.

    2012-01-01

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infraredinterferometer designed to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer tosimultaneously obtain spatial and spectral information on science targets; the long baseline permits subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. Here, we present key aspects of the overall design of the mission and provide an overview of the current status of the project. We also discuss briefly the implications of this experiment for future space-based far-infrared interferometers.

  6. Interferometric chromatic dispersion measurements of long, gradient-index rod lenses in the visible and the near infrared.

    PubMed

    Tomkinson, T H; Moore, D T

    1999-09-01

    A new procedure is presented for testing long, radial-gradient-index rod lenses in a phase-stepping Twyman-Green interferometer. In addition, a method for converting the measured optical phase data to the rod's index of refraction profile is reviewed. This procedure was used to measure refractive-index profile dispersions over the wavelength range of 441 to 1064 nm. These measurements provide the first data for refractive-index profiles of rod lenses in the infrared and show the existence of positive dispersion, negative dispersion, and near-infrared dispersion reversal in some samples. The dispersion results suggest the need for modifications to the current glass model.

  7. Addressing Thermal Model Run Time Concerns of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA)

    NASA Technical Reports Server (NTRS)

    Peabody, Hume; Guerrero, Sergio; Hawk, John; Rodriguez, Juan; McDonald, Carson; Jackson, Cliff

    2016-01-01

    The Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) utilizes an existing 2.4 m diameter Hubble sized telescope donated from elsewhere in the federal government for near-infrared sky surveys and Exoplanet searches to answer crucial questions about the universe and dark energy. The WFIRST design continues to increase in maturity, detail, and complexity with each design cycle leading to a Mission Concept Review and entrance to the Mission Formulation Phase. Each cycle has required a Structural-Thermal-Optical-Performance (STOP) analysis to ensure the design can meet the stringent pointing and stability requirements. As such, the models have also grown in size and complexity leading to increased model run time. This paper addresses efforts to reduce the run time while still maintaining sufficient accuracy for STOP analyses. A technique was developed to identify slews between observing orientations that were sufficiently different to warrant recalculation of the environmental fluxes to reduce the total number of radiation calculation points. The inclusion of a cryocooler fluid loop in the model also forced smaller time-steps than desired, which greatly increases the overall run time. The analysis of this fluid model required mitigation to drive the run time down by solving portions of the model at different time scales. Lastly, investigations were made into the impact of the removal of small radiation couplings on run time and accuracy. Use of these techniques allowed the models to produce meaningful results within reasonable run times to meet project schedule deadlines.

  8. Interferometric Remapped Array Nulling

    NASA Astrophysics Data System (ADS)

    Vakili, F.; Aristidi, E.; Abe, L.; Lopez, B.

    2004-07-01

    This paper describes a method of beam-combination in the so-called hypertelescope imaging technique recently introduced by Labeyrie in optical interferometry. The method we propose is an alternative to the Michelson pupil reconfiguration that suffers from the loss of the classical object-image convolution relation. From elementary theory of Fourier optics we demonstrate that this problem can be solved by reconfiguring images instead of pupils. Imaging is performed in a combined pupil-plane where the point-source intensity distribution (PSID by comparison to the more commonly quoted point-spread function, PSF) tends towards a pseudo Airy disc for a sufficiently large number of telescopes. Our method is applicable to snap-shot imaging of extended sources with a field limited to the Airy pattern of single telescopes operated in a co-phased multi-aperture interferometric array. It thus allows to apply conveniently pupil plane coronagraphy. Our technique called Interferometric Remapped Array Nulling (IRAN) is particularly suitable for high dynamic imaging of extra-solar planetary companions or extra-galactic objects where long baseline interferometry would closely probe the central regions of AGNs for instance. We also discuss the application of IRAN to improve the performances of imaging and/or nulling interferometers like the full-fledged VLTI array or the DARWIN space-borne mission.

  9. Conceptual design of a cryogenic system for the next-generation infrared space telescope SPICA

    NASA Astrophysics Data System (ADS)

    Sato, Y.; Sugita, H.; Shinozaki, K.; Okamoto, A.; Yamawaki, T.; Komatsu, K.; Nakagawa, T.; Murakami, H.; Matsuhara, H.; Murakami, M.; Takada, M.; Takai, S.; Okabayashi, A.; Kanao, K.; Tsunematsu, S.; Otsuka, K.; Narasaki, K.

    2010-07-01

    The conceptual design of the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) has been studied as a pre-project of the Japan Aerospace Exploration Agency (JAXA) in collaboration with ESA to be launched in 2018. The SPICA is transferred into a halo orbit around the second Lagrangian point in the Sun-Earth system, where radiant cooling is available effectively. The SPICA has a large IR telescope 3 m in diameter, which is cooled without cryogen to below 6 K by the radiant and mechanical cooling system. Therefore, the SPICA mission will cover mid- and far-IR astronomy with high sensitivity and spatial resolution during a long period of over 5 years for goal. Most heat radiation from the sun and spacecraft is blocked by the Sun Shield and thermal radiation shields covered with Multi-Layer Insulator (MLI) to limit heat radiation to the Scientific Instrument Assembly (SIA). The SIA, which is composed of the primary mirrors and optical benches equipped with Focal Plane Instruments (FPIs), is refrigerated to below 6 K by two sets of 4K-class Joule-Thomson (JT) cooler with a cooling power of 40 mW at 4.5 K. The Far-IR detector is refrigerated to 1.7 K by two sets of 1K-class JT coolers with a cooling power of 10 mW at 1.7 K. Improvements for the higher reliability and sufficient cooling performance are required in the development of SPICA mechanical cryocoolers. Thermal analysis indicates that the SPICA cryogenic system works effectively to limit the total heat load on the SIA to 41.2 mW. This paper describes the conceptual design of the SPICA cryogenic system, which was established with thermal feasibility for nominal operation mode.

  10. Prime Focus Spectrograph for the Subaru telescope: massively multiplexed optical and near-infrared fiber spectrograph

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Tamura, Naoyuki; Karoji, Hiroshi; Shimono, Atsushi; Takato, Naruhisa; Kimura, Masahiko; Ohyama, Youichi; Ueda, Akitoshi; Aghazarian, Hrand; de Arruda, Marcio Vital; Barkhouser, Robert H.; Bennett, Charles L.; Bickerton, Steve; Bozier, Alexandre; Braun, David F.; Bui, Khanh; Capocasale, Christopher M.; Carr, Michael A.; Castilho, Bruno; Chang, Yin-Chang; Chen, Hsin-Yo; Chou, Richard C. Y.; Dawson, Olivia R.; Dekany, Richard G.; Ek, Eric M.; Ellis, Richard S.; English, Robin J.; Ferrand, Didier; Ferreira, Décio; Fisher, Charles D.; Golebiowski, Mirek; Gunn, James E.; Hart, Murdock; Heckman, Timothy M.; Ho, Paul T. P.; Hope, Stephen; Hovland, Larry E.; Hsu, Shu-Fu; Hu, Yen-Shan; Huang, Pin Jie; Jaquet, Marc; Karr, Jennifer E.; Kempenaar, Jason G.; King, Matthew E.; Fèvre, Olivier Le; Mignant, David Le; Ling, Hung-Hsu; Loomis, Craig; Lupton, Robert H.; Madec, Fabrice; Mao, Peter; Marrara, Lucas Souza; Ménard, Brice; Morantz, Chaz; Murayama, Hitoshi; Murray, Graham J.; de Oliveira, Antonio Cesar; de Oliveira, Claudia Mendes; de Oliveira, Ligia Souza; Orndorff, Joe D.; de Paiva Vilaça, Rodrigo; Partos, Eamon J.; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J.; Riddle, Reed; Santos, Leandro; dos Santos, Jesulino Bispo; Schwochert, Mark A.; Seiffert, Michael D.; Smee, Stephen A.; Smith, Roger M.; Steinkraus, Ronald E.; Sodré, Laerte; Spergel, David N.; Surace, Christian; Tresse, Laurence; Vidal, Clément; Vives, Sebastien; Wang, Shiang-Yu; Wen, Chih-Yi; Wu, Amy C.; Wyse, Rosie; Yan, Chi-Hung

    2015-07-01

    The Prime Focus Spectrograph (PFS) is an optical/near-infrared multifiber spectrograph with 2394 science fibers distributed across a 1.3-deg diameter field of view at the Subaru 8.2-m telescope. The wide wavelength coverage from 0.38 μm to 1.26 μm, with a resolving power of 3000, simultaneously strengthens its ability to target three main survey programs: cosmology, galactic archaeology and galaxy/AGN evolution. A medium resolution mode with a resolving power of 5000 for 0.71 μm to 0.89 μm will also be available by simply exchanging dispersers. We highlight some of the technological aspects of the design. To transform the telescope focal ratio, a broad-band coated microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of the cable system, optimizing overall throughput; a fiber with low focal ratio degradation is selected for the fiber-positioner and fiber-slit components, minimizing the effects of fiber movements and fiber bending. Fiber positioning will be performed by a positioner consisting of two stages of piezo-electric rotary motors. The positions of these motors are measured by taking an image of artificially back-illuminated fibers with the metrology camera located in the Cassegrain container; the fibers are placed in the proper location by iteratively measuring and then adjusting the positions of the motors. Target light reaches one of the four identical fast-Schmidt spectrograph modules, each with three arms. The PFS project has passed several project-wide design reviews and is now in the construction phase.

  11. Mid-infrared observations of sungrazing comet C/2012 S1 (ISON) with the Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Ootsubo, T.; Usui, F.; Takita, S.; Watanabe, J.; Yanamandra-Fisher, P.; Honda, M.; Kawakita, H.; Furusho, R.

    2014-07-01

    Comets are the frozen reservoirs of the early solar nebula and are made of ice and dust. The determination of the properties for cometary dust provides us insight into both the early-solar-nebula environment and the formation process of the planetary system. A silicate feature is often observed in comet spectra in the mid-infrared region and may be used for probing the early history of the solar system. In most cases, the feature shows the existence of crystalline silicate (for example, 11.3 microns) together with amorphous silicate [1,2]. Since the crystallization of silicates from amorphous ones generally requires high-temperature annealing above 800 K (e.g., [3,4]), it is believed that the crystalline silicate grains produced at the inner part of the disk were transported to the outer cold regions where the comet nuclei formed. Comet C/2012 S1 (ISON) is a long-period Oort Cloud comet, discovered in September 2012. In particular, comet ISON is a sungrazing comet, which was predicted to pass close by the Sun and the Earth and becoming a bright object. Mid-infrared observations of this new comet and investigation of the 10-micron silicate feature help us understand the formation of crystalline silicate grains in the early solar nebula. We conducted observations of comet ISON in the mid-infrared wavelength region with the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on the Subaru Telescope on Mauna Kea, Hawaii [5,6,7]. The observation of comet ISON was carried out on 2013 October 19 and 21 UT. Since the weather conditions were not so good when we observed, we carried out N-band imaging observations (8.8 and 12.4 microns) and N-band low-resolution spectroscopy. The spectrum of comet ISON can be fit with the 260--265-K blackbody spectrum when we use the regions of 7.8--8.2 and 12.4--13.0 microns as the continuum. The spectrum has only a weak silicate excess feature, which may be able to attribute to small amorphous olivine grains. We could not detect a clear

  12. AN INTERFEROMETRIC STUDY OF THE FOMALHAUT INNER DEBRIS DISK. I. NEAR-INFRARED DETECTION OF HOT DUST WITH VLTI/VINCI

    SciTech Connect

    Absil, Olivier; Mennesson, Bertrand; Le Bouquin, Jean-Baptiste; Di Folco, Emmanuel; Kervella, Pierre; Augereau, Jean-Charles

    2009-10-10

    The innermost parts of dusty debris disks around main-sequence stars are currently poorly known due to the high contrast and small angular separation with their parent stars. Using near-infrared interferometry, we aim to detect the signature of hot dust around the nearby A4 V star Fomalhaut, which has already been suggested to harbor a warm dust population in addition to a cold dust ring located at about 140 AU. Archival data obtained with the VINCI instrument at the VLTI are used to study the fringe visibility of the Fomalhaut system at projected baseline lengths ranging from 4 m to 140 m in the K band. A significant visibility deficit is observed at short baselines with respect to the expected visibility of the sole stellar photosphere. This is interpreted as the signature of resolved circumstellar emission, producing a relative flux of 0.88% +- 0.12% with respect to the stellar photosphere. While our interferometric data cannot directly constrain the morphology of the excess emission source, complementary data from the literature allow us to discard an off-axis point-like object as the source of circumstellar emission. We argue that the thermal emission from hot dusty grains located within 6 AU from Fomalhaut is the most plausible explanation for the detected excess. Our study also provides a revised limb-darkened diameter for Fomalhaut (theta{sub LD} = 2.223 +- 0.022 mas), taking into account the effect of the resolved circumstellar emission.

  13. The Space Infrared Telescope for Cosmology and Astrophysics and Pending US Contribution

    NASA Astrophysics Data System (ADS)

    Bradford, Charles; SPICA Consortium; SAFARI Consortium

    2017-01-01

    SPICA is a cryogenic space-borne observatory designed for optimal sensitivity in the mid-infrared through submillimeter range: 17-250 microns. The mission is an ESA / JAXA collaboration, now under review in the ESA Cosmic Visions M5 opportunity, which has final approval in 2019, and launch in the late 2020 decade. SPICA will feature a 2.5-meter telescope cooled to below 8K, this offers the potential for 100-1000-fold advances in sensitivity beyond that obtained with Herschel and SOFIA in the far-IR. With a line sensitivity of ~5x10^-20 W/m^2 (1 h, 5 sigma), SPICA will be a complement to JWST and ALMA for deep spectroscopic observations. Integrated over cosmic history, star formation has occurred predominantly in dust-obscured regions which are inaccessible in the rest-frame UV and optical. Both the luminosity history and the detailed physics that govern it can only be directly measured in the mid-IR-submillimeter. Similarly, forming stars and planetary systems cool primarily through the far-IR. By taking advantage of the low-background platform, the SPICA instruments are designed for these investigations. The SPICA mid-IR instrument (SMI) will provide R~50 imaging spectroscopy and R~1,000 full-band slit-fed spectroscopy from 17 to 36 microns, with a high-resolution (R=25,000) capability from 12-18 microns. The SPICA far-IR instrument (SAFARI) will cover 34 to at least 250 microns with multiple R~300 wide-band grating spectrometer modules coupling to high-sensitivity far-IR detectors. A R~3,000 scanned-etalon module will also be available for Galactic targets with bright continua and/or dense line spectra. In the current SPICA division of responsibilities, ESA will take the lead role, provide the telescope, the fine-attitude sensor, and the spacecraft bus. JAXA will provide the cryogenic system, the SMI instrument, integrate the telescope and instruments, and provide the launch vehicle. The SAFARI instrument will be provided by a consortium funded by the European

  14. The Hubble Space Telescope Survey of BL Lacertae Objects. IV. Infrared Imaging of Host Galaxies

    NASA Astrophysics Data System (ADS)

    Scarpa, Riccardo; Urry, C. Megan; Padovani, Paolo; Calzetti, Daniela; O'Dowd, Matthew

    2000-11-01

    The Hubble Space Telescope NICMOS Camera 2 was used for H-band imaging of 12 BL Lacertae objects taken from the larger sample observed with the WFPC2 in the R band by Urry and coworkers and Scarpa and coworkers. Ten of the 12 BL Lacs are clearly resolved, and the detected host galaxies are large, bright ellipticals with average absolute magnitude =-26.2+/-0.45 mag and effective radius =10+/-5 kpc. The rest-frame integrated color of the host galaxies is on average =2.3+/-0.3, consistent with the value for both radio galaxies and normal, nonactive elliptical galaxies and indicating that the dominant stellar population is old. The host galaxies tend to be bluer in their outer regions than in their cores, with average color gradient Δ(R-H)/Δlogr=-0.2 mag, again consistent with results for normal nonactive elliptical galaxies. The infrared Kormendy relation, derived for the first time for BL Lac host galaxies, is μe=3.8logre+14.8, fully in agreement with the relation for normal ellipticals. The close similarity between BL Lac host galaxies and normal ellipticals suggests that the active nucleus has surprisingly little effect on the host galaxy. This supports a picture in which all elliptical galaxies harbor black holes that can be actively accreting for some fraction of their lifetime.

  15. Mid-infrared imaging of 18 planetary nebulae using the Spitzer Space Telescope

    NASA Astrophysics Data System (ADS)

    Phillips, J. P.; Ramos-Larios, G.

    2008-01-01

    We present 3.6-, 4.5-, 5.8- and 8.0-μm photometric mapping of 18 galactic planetary nebulae, based on observations taken with the Spitzer Space Telescope. These are shown to have morphologies which are sometimes quite different from those observed in the visible, with much of the emission arising outside the ionized shells. There is also evidence for a change in nebular sizes between the differing photometric bands. An analysis of mid-infrared (MIR) colours suggests that many nebulae have dust/polycyclic aromatic hydrocarbon (PAH) emission components, and it seems likely that longer wave MIR fluxes (in particular) are associated with PAH emission features. Such features are likely to be associated, in addition, with photodissociative regimes, where shock fragmentation of dust may lead to the replenishment of smaller PAH grains. Finally, we note that the source Ap 2-1 possesses a particularly interesting structure, and may represent a case in which the nebular shell is ploughing through an enveloping HII region. Similarly, it appears that central emission in M 2-48 may arise from a warm and dusty collimating disc.

  16. Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

    NASA Technical Reports Server (NTRS)

    Gong, Qian; Content, David; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas; Whipple, Arthur

    2016-01-01

    The slitless spectrometer plays an important role in the Wide-Field InfraRed Survey Telescope (WFIRST) mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies. The concept of the compound grism as a slitless spectrometer has been presented previously. The presentation briefly discusses the challenges and solutions of the optical design, and recent specification updates, as well as a brief comparison between the prototype and the latest design. However, the emphasis of this paper is the progress of the grism prototype: the fabrication and test of the complicated diffractive optical elements and powered prism, as well as grism assembly alignment and testing. Especially how to use different tools and methods, such as IR phase shift and wavelength shift interferometry, to complete the element and assembly tests. The paper also presents very encouraging results from recent element tests to assembly tests. Finally we briefly touch the path forward plan to test the spectral characteristic, such as spectral resolution and response.

  17. Emergency relief venting of the infrared telescope liquid helium dewar, second edition

    NASA Technical Reports Server (NTRS)

    Urban, E. W.

    1981-01-01

    An updated analysis is made of the emergency relief venting of the liquid helium dewar of the Spacelab 2 Infrared Telescope experiment in the event of a massive failure of the dewar guard vacuum. Such a failure, resulting from a major accident, could cause rapid heating and pressurization of the liquid helium in the dewar and lead to relief venting through the emergency relief system. The heat input from an accident is estimated for various fluid conditions in the dewar and the relief process considered as it takes place through one or both of the emergency relief paths. It was previously assumed that the burst diaphragms in the dewar relief paths would rupture at a pressure of 65 psi differential or 4.4 atmospheres. In fact, it has proved necessary to use burst diaphragms in the dewar which rupture at 115 psid or 7.8 atmospheres. An analysis of this case was carried out and shows that when the high pressure diaphragm rupture occurs, the dewar pressure falls within 8 s to below the 4.4 atmospheres for which the original analysis was performed, and thereafter it remains below that level.

  18. Optimal Out-Of-Ecliptic Orbits for Short-Term Space-Borne Infrared Telescope Missions

    NASA Astrophysics Data System (ADS)

    Nir, Gali; Gurfil, Pini

    2011-01-01

    This paper presents a new approach for designing orbits for infrared (IR) space-borne observatories using multiple gravity assists. A large displacement normal to the ecliptic plane mitigates the noise generated by the local zodiacal dust, thereby reducing the size, weight, and complexity of the telescope. Although previous works focused on long-term missions, allowing very long transfer times to out-of-ecliptic orbits, this paper considers short-duration missions, for which the transfer times are tightly constrained. To reduce the transfer time, the flyby sequence includes the inner planets only: Venus, Earth, and Mars. Moreover, in order to reduce energy requirements, a fuel-optimal multiple gravity-assisted trajectory is designed. The problem is modeled using the patched-conic approximation and solved using a hybrid genetic algorithm coupled to a pattern search. Efficient trajectories requiring a minimum velocity addition, although providing a maximum observation time, are found and validated using an N-body simulation. The TPF-I mission is used as a benchmark in order to quantify the benefits of an out-of-ecliptic orbit. It is shown that the newly found orbits allow a reduction in the collector area compared to halo orbits.

  19. MEASURING HIGH-PRECISION ASTROMETRY WITH THE INFRARED ARRAY CAMERA ON THE SPITZER SPACE TELESCOPE

    SciTech Connect

    Esplin, T. L.; Luhman, K. L.

    2016-01-15

    The Infrared Array Camera (IRAC) on the Spitzer Space Telescope currently offers the greatest potential for high-precision astrometry of faint mid-IR sources across arcminute-scale fields, which would be especially valuable for measuring parallaxes of cold brown dwarfs in the solar neighborhood and proper motions of obscured members of nearby star-forming regions. To more fully realize IRAC's astrometric capabilities, we have sought to minimize the largest sources of uncertainty in astrometry with its 3.6 and 4.5 μm bands. By comparing different routines that estimate stellar positions, we have found that Point Response Function (PRF) fitting with the Spitzer Science Center's Astronomical Point Source Extractor produces both the smallest systematic errors from varying intra-pixel sensitivity and the greatest precision in measurements of positions. In addition, self-calibration has been used to derive new 7th and 8th order distortion corrections for the 3.6 and 4.5 μm arrays of IRAC, respectively. These corrections are suitable for data throughout the mission of Spitzer when a time-dependent scale factor is applied to the corrections. To illustrate the astrometric accuracy that can be achieved by combining PRF fitting with our new distortion corrections, we have applied them to archival data for a nearby star-forming region, arriving at total astrometric errors of ∼20 and 70 mas at signal to noise ratios of 100 and 10, respectively.

  20. Primary mirror and mount technology for the Stratospheric Observatory for Infrared Astronomy (SOFIA) telescope

    NASA Technical Reports Server (NTRS)

    Melugin, Ramsey K.; Chang, L. S.; Mansfield, J. A.; Howard, Steven D.

    1989-01-01

    Candidate technologies for a lightweight primary mirror for the SOFIA telescope are evaluated for both mirror blank fabrication and polishing. Two leading candidates for the type mirror blank are considered: the frit-bonded, structured form, and the thin meniscus form. The feasible mirror is required to be very lightweight with an areal density of approximately 100 kg/sq m, have an f/ratio near 1.0, and have surface quality that permits imaging in the visible as well as the infrared. Also considered are the results of a study conducted to assess the feasibility of designing a suitable mounting system for the primary mirror. The requirements for the mount design are given both in terms of the environmental conditions and the expected optical performance. PATRAN and NASTRAN programs are used to model mirror and mounting. The sandwich-type mirror made of ultra low expansion silica with square cells in the core, is modeled using equivalent solid elements for the core. The design study produces primary mirror surface deflections in 1g as a function of mirror elevation angles. The surface is analyzed using an optical analysis program, FRINGE, to give a prediction of the mirror optical performance. Results from this analysis are included.

  1. Thirty Meter Telescope narrow-field infrared adaptive optics system real-time controller prototyping results

    NASA Astrophysics Data System (ADS)

    Smith, Malcolm; Kerley, Dan; Chapin, Edward L.; Dunn, Jennifer; Herriot, Glen; Véran, Jean-Pierre; Boyer, Corinne; Ellerbroek, Brent; Gilles, Luc; Wang, Lianqi

    2016-07-01

    Prototyping and benchmarking was performed for the Real-Time Controller (RTC) of the Narrow Field InfraRed Adaptive Optics System (NFIRAOS). To perform wavefront correction, NFIRAOS utilizes two deformable mirrors (DM) and one tip/tilt stage (TTS). The RTC receives wavefront information from six Laser Guide Star (LGS) Shack- Hartmann WaveFront Sensors (WFS), one high-order Natural Guide Star Pyramid WaveFront Sensor (PWFS) and multiple low-order instrument detectors. The RTC uses this information to determine the commands to send to the wavefront correctors. NFIRAOS is the first light AO system for the Thirty Meter Telescope (TMT). The prototyping was performed using dual-socket high performance Linux servers with the real-time (PREEMPT_RT) patch and demonstrated the viability of a commercial off-the-shelf (COTS) hardware approach to large scale AO reconstruction. In particular, a large custom matrix vector multiplication (MVM) was benchmarked which met the required latency requirements. In addition all major inter-machine communication was verified to be adequate using 10Gb and 40Gb Ethernet. The results of this prototyping has enabled a CPU-based NFIRAOS RTC design to proceed with confidence and that COTS hardware can be used to meet the demanding performance requirements.

  2. Cryogenic near infrared spectropolarimeter for the Daniel K. Inouye Solar Telescope

    NASA Astrophysics Data System (ADS)

    Fehlmann, Andre; Giebink, Cynthia; Kuhn, Jeffrey R.; Messersmith, Ernesto J.; Mickey, Donald L.; Scholl, Isabelle F.; James, Don; Hnat, Kirby; Schickling, Greg; Schickling, Richard

    2016-08-01

    The Cryogenic Near Infrared Spectropolarimeter for the Daniel K Inouye Solar Telescope is designed to measure polarized light from 0.5 to 5 μm. It uses an almost all reflective design for high throughput and an R2 echelle grating to achieve the required resolution of up to R = 100,000. The optics cooled to cryogenic temperatures reduce the thermal background allowing for IR observations of the faint solar corona. Both the spectrograph and its context imager use H2RG detector arrays with a newly designed controller to allow synchronized exposures at frame rates up to 10 Hz. All hardware has been built and tested and the key components met their design goals. 1) The cryogenic system uses mechanical closed cycle coolers which introduce vibrations. Our design uses a two stage approach with a floating mounting disk and flexible cold links to reduce these. The vibration amplitudes on all critical stages were measured and are smaller than 1μm. 2) The grating stage of the spectrograph uses a double stack of harmonic drives and an optical encoder to provide sub-arcsecond resolution and a measured repeatability of better than 0.5 arcsec.

  3. European agreement on James Webb Space Telescope's Mid-Infrared Instrument (MIRI) signed

    NASA Astrophysics Data System (ADS)

    2004-06-01

    Artist's impression of the JWST hi-res Size hi-res: 1601 kb Credits: ESA Artist's impression of the JWST An artist's impression of the selected design for the JWST spacecraft. Northrop Grumman and Ball Aerospace are the prime contractors for JWST. Artist's impression of the JWST Credits: ESA Artist's impression of the JWST An artist's impression of the selected design for the JWST spacecraft. Northrop Grumman and Ball Aerospace are the prime contractors for JWST. Observing the first light, the James Webb Space Telescope (JWST) will help to solve outstanding questions about our place in the evolving Universe. MIRI, the Mid-Infrared Instrument, is one of the four instruments on board the JWST, the mission scheduled to follow on the heritage of Hubble in 2011. MIRI will be built in cooperation between Europe and the United States (NASA), both equally contributing to its funding. MIRI’s optics, core of the instrument, will be provided by a consortium of European institutes. According to this formal agreement, ESA will manage and co-ordinate the whole development of the European part of MIRI and act as the sole interface with NASA, which is leading the JWST project. This marks a difference with respect to the previous ESA scientific missions. In the past the funding and the development of the scientific instruments was agreed by the participating ESA Member States on the basis of purely informal arrangements with ESA. In this case, the Member States involved in MIRI have agreed on formally guaranteeing the required level of funding on the basis of a multi-lateral international agreement, which still keeps scientists in key roles. Over the past years, missions have become more complex and demanding, and more costly within an ever tighter budget. They also require a more and more specific expertise which is spread throughout the vast European scientific community. As a result, a new management procedure for co-ordination of payload development has become a necessity to

  4. James Webb Space Telescope Mid Infra-Red Instrument Pulse-Tube Cryocooler Electronics

    NASA Technical Reports Server (NTRS)

    Harvey, D.; Flowers, T.; Liu, N.; Moore, K.; Tran, D.; Valenzuela, P.; Franklin, B.; Michaels, D.

    2013-01-01

    The latest generation of long life, space pulse-tube cryocoolers require electronics capable of controlling self-induced vibration down to a fraction of a newton and coldhead temperature with high accuracy down to a few kelvin. Other functions include engineering diagnostics, heater and valve control, telemetry and safety protection of the cryocooler subsystem against extreme environments and operational anomalies. The electronics are designed to survive the thermal, vibration, shock and radiation environment of launch and orbit, while providing a design life in excess of 10 years on-orbit. A number of our current generation high reliability radiation-hardened electronics units are in various stages of integration on several space flight payloads. This paper describes the features and performance of our latest flight electronics designed for the pulse-tube cryocooler that is the pre-cooler for a closed cycle Joule-Thomson cooler providing 6K cooling for the James Webb Space Telescope (JWST) Mid Infra-Red Instrument (MIRI). The electronics is capable of highly accurate temperature control over the temperature range from 4K to 15K. Self-induced vibration is controlled to low levels on all harmonics up to the 16th. A unique active power filter controls peak-to-peak reflected ripple current on the primary power bus to a very low level. The 9 kg unit is capable of delivering 360W continuous power to NGAS's 3-stage pulse-tube High-Capacity Cryocooler (HCC).

  5. Selection of infrared black(s) for the Space Infra-Red Telescope Facility (SIRTF): a surface-by-surface performance comparison

    NASA Astrophysics Data System (ADS)

    Dinger, Ann S.

    1994-10-01

    SIRTF, the Space Infrared Telescope Facility, is planned to be the final one of NASA's four great observatories. It is a cryogenically cooled telescope designed to perform background- limited observations at all wavelengths between 2 and 220 micrometers . This stringent straylight requirement necessitates the use of infrared black coatings on all non-optical telescope surfaces. In order to make an informed decision, the SIRTF Study Office supported a long- range program to characterize the performance of a variety of black coatings over the full SIRTF wavelength range. Measurements of both specular reflectance and BRDF made by Sheldon Smith were incorporated into a model that predicts the blacks' BRDF coefficients at other wavelengths. The restrahlen reflectance peaks of Martin Black and Martin Infrablack at 2.2 and 5.4 micrometers are included in the model. An APART analysis of the current SIRTF telescope design was performed at wavelengths of 2.2, 3.5, 12.5, 60, and 200 micrometers . Evaluation of the relative performances of Martin Optical Black and Ames 24E2 on several critical surfaces led to the conclusion that the SIRTF straylight rejection could be enhanced by selecting different coatings for different surfaces. A very diffuse black is best on the mirror stops and secondary support struts, while a specular black could be a better choice for the vaned telescope barrel. Many coatings that are black and diffusely scattering at short wavelengths become quite bright and specular at long wavelengths. Extreme caution must be taken when using a black that becomes specular on any surface that can be seen from the telescope plane.

  6. Simultaneous seeing measurement through the Subaru Telescope in the visible and near-infrared bands for the wavelength dependence evaluation

    NASA Astrophysics Data System (ADS)

    Oya, Shin; Terada, Hiroshi; Hayano, Yutaka; Watanabe, Makoto; Hattori, Masayuki; Minowa, Yosuke

    2016-08-01

    Stellar images have been obtained under natural seeing at visible and near-infrared wavelengths simultaneously through the Subaru Telescope at Mauna Kea. The image quality is evaluated by the full-width at the half-maximum (FWHM) of the stellar images. The observed ratio of FWHM in the V-band to the K-band is 1.54 ± 0.17 on average. The ratio shows tendency to decrease toward bad seeing as expected from the outer scale influence, though the number of the samples is still limited. The ratio is important for simulations to evaluate the performance of a ground-layer adaptive optics system at near-infrared wavelengths based on optical seeing statistics. The observed optical seeing is also compared with outside seeing to estimate the dome seeing of the Subaru Telescope.

  7. Development of infrared Echelle spectrograph and mid-infrared heterodyne spectrometer on a small telescope at Haleakala, Hawaii for planetary observation

    NASA Astrophysics Data System (ADS)

    Sakanoi, Takeshi; Kasaba, Yasumasa; Kagitani, Masato; Nakagawa, Hiromu; Kuhn, Jeff; Okano, Shoichi

    2014-08-01

    We report the development of infrared Echelle spectrograph covering 1 - 4 micron and mid-infrared heterodyne spectrometer around 10 micron installed on the 60-cm telescope at the summit of Haleakala, Hawaii (alt.=3000m). It is essential to carry out continuous measurement of planetary atmosphere, such as the Jovian infrared aurora and the volcanoes on Jovian satellite Io, to understand its time and spatial variations. A compact and easy-to-use high resolution infrared spectrometer provide the good opportunity to investigate these objects continuously. We are developing an Echelle spectrograph called ESPRIT: Echelle Spectrograph for Planetary Research In Tohoku university. The main target of ESPRIT is to measure the Jovian H3+ fundamental line at 3.9 micron, and H2 nu=1 at 2.1 micron. The 256x256 pixel CRC463 InSb array is used. An appropriate Echelle grating is selected to optimize at 3.9 micron and 2.1 micron for the Jovian infrared auroral observations. The pixel scale corresponds to the atmospheric seeing (0.3 arcsec/pixel). This spectrograph is characterized by a long slit field-of-view of ~ 50 arcsec with a spectral resolution is over 20,000. In addition, we recently developed a heterodyne spectrometer called MILAHI on the 60 cm telescope. MILAHI is characterized by super high-resolving power (more than 1,500,000) covering from 7 - 13 microns. Its sensitivity is 2400 K at 9.6 micron with a MCT photo diode detector of which bandwidth of 3000 MHz. ESPRIT and MILAHI is planned to be installed on 60 cm telescope is planned in 2014.

  8. Feasibility of using Extreme Ultraviolet Explorer (EUVE) reaction wheels to satisfy Space Infrared Telescope Facility (SIRTF) maneuver requirements

    NASA Technical Reports Server (NTRS)

    Lightsey, W. D.

    1990-01-01

    A digital computer simulation is used to determine if the extreme ultraviolet explorer (EUVE) reaction wheels can provide sufficient torque and momentum storage capability to meet the space infrared telescope facility (SIRTF) maneuver requirements. A brief description of the pointing control system (PCS) and the sensor and actuator dynamic models used in the simulation is presented. A model to represent a disturbance such as fluid sloshing is developed. Results developed with the simulation, and a discussion of these results are presented.

  9. IRAN: interferometric remapped array nulling

    NASA Astrophysics Data System (ADS)

    Aristidi, Eric; Vakili, Farrokh; Abe, Lyu; Belu, Adrian; Lopez, Bruno; Lanteri, Henri; Schutz, A.; Menut, Jean-Luc

    2004-10-01

    This paper describes a method of beam-combination in the so-called hypertelescope imaging technique recently introduced by Labeyrie in optical interferometry. The method we propose is an alternative to the Michelson pupil reconfiguration that suffers from the loss of the classical object-image convolution relation. From elementary theory of Fourier optics we demonstrate that this problem can be solved by observing in a combined pupil plane instead of an image plane. The point-source intensity distribution (PSID) of this interferometric "image" tends towards a psuedo Airy disc (similar to that of a giant monolithic telescope) for a sufficiently large number of telescopes. Our method is applicable to snap-shot imaging of extended sources with a field comparable to the Airy pattern of single telescopes operated in a co-phased multi-aperture interferometric array. It thus allows to apply conveniently pupil plane coronagraphy. Our technique called Interferometric Remapped Array Nulling (IRAN) is particularly suitable for high dynamic imaging of extra-solar planetary companions, circumstellar nebulosities or extra-galactic objects where long baseline interferometry would closely probe the central regions of AGNs for instance.

  10. A Road Map for the Generation of a Near-Infrared Guide Star Catalog for Thirty Meter Telescope Observations

    NASA Astrophysics Data System (ADS)

    Subramanian, Smitha; Subramaniam, Annapurni; Sivarani, T.; Simard, Luc; Anupama, G. C.; Gillies, Kim; Ramaprakash, A. N.; Reddy, B. Eswar

    2016-09-01

    The near-infrared instruments in the upcoming Thirty Meter Telescope (TMT) will be assisted by a multi conjugate Adaptive Optics (AO) system. For the efficient operation of the AO system, during observations, a near-infrared guide star catalog which goes as faint as 22 mag in JVega band is essential and such a catalog does not exist. A methodology, based on stellar atmospheric models, to compute the expected near-infrared magnitudes of stellar sources from their optical magnitudes is developed. The method is applied and validated in JHKs bands for a magnitude range of JVega 16-22 mag. The methodology is also applied and validated using the reference catalog of PAN STARRS. We verified that the properties of the final PAN STARRS optical catalog will satisfy the requirements of TMT IRGSC and will be one of the potential sources for the generation of the final catalog. In a broader context, this methodology is applicable for the generation of a guide star catalog for any existing/upcoming near-infrared telescopes.

  11. Cryogenic Optical Performance of the Cassini Composite InfraRed Spectrometer (CIRS) Flight Telescope

    NASA Technical Reports Server (NTRS)

    Losch, Patricia; Lyons, James J., III; Hagopian, John

    1998-01-01

    The CIRS half-meter diameter beryllium flight telescope's optical performance was tested at the instrument operating temperature of 170 Kelvin. The telescope components were designed at Goddard Space Flight Center (GSFC) but fabricated out of house and then assembled, aligned and tested upon receipt at GSFC. A 24 inch aperture cryogenic test facility utilizing a 1024 x 1024 CCD array was developed at GSFC specifically for this test. The telescope,s image quality (measured as encircled energy), boresight stability and focus stability were measured. The gold coated beryllium design exceeded the cold image performance requirement of 80% encircled energy within a 460 micron diameter circle.

  12. Space Infrared Astronomy in the 21st Century

    NASA Technical Reports Server (NTRS)

    Mather, John C.; Fisher, Richard (Technical Monitor)

    2000-01-01

    New technology and design approaches have enabled revolutionary improvements in astronomical observations from space. Worldwide plans and dreams include orders of magnitude growth in sensitivity and resolution for all wavelength ranges, and would give the ability to learn our history, from the Big Bang to the conditions for life on Earth. The Next Generation Space Telescope, for example, will be able to see the most distant galaxies as they were being assembled from tiny fragments. It will be 1/4 as massive as the Hubble, with a mirror 3 times as large, cooled to about 30 Kelvin to image infrared radiation. I will discuss plans for NGST and hopes for future large space telescopes, ranging from the Space UV Optical (SUVO) telescope to the Filled Aperture Infrared (FAIR) Telescope, the Space Infrared Interferometric Telescope (SPIRIT), and the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS).

  13. Infrared Doppler instrument (IRD) for the Subaru telescope to search for Earth-like planets around nearby M-dwarfs

    NASA Astrophysics Data System (ADS)

    Kotani, Takayuki; Tamura, Motohide; Suto, Hiroshi; Nishikawa, Jun; Sato, Bun'ei; Aoki, Wako; Usuda, Tomonori; Kurokawa, Takashi; Kashiwagi, Ken; Nishiyama, Shogo; Ikeda, Yuji; Hall, Donald B.; Hodapp, Klaus W.; Hashimoto, Jun; Morino, Jun-Ichi; Okuyama, Yasushi; Tanaka, Yosuke; Suzuki, Shota; Inoue, Sadahiro; Kwon, Jungmi; Suenaga, Takuya; Oh, Dehyun; Baba, Haruka; Narita, Norio; Kokubo, Eiichiro; Hayano, Yutaka; Izumiura, Hideyuki; Kambe, Eiji; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Ikoma, Masahiro; Hori, Yasunori; Omiya, Masashi; Genda, Hidenori; Fukui, Akihiko; Fujii, Yuka; Guyon, Olivier; Harakawa, Hiroki; Hayashi, Masahiko; Hidai, Masahide; Hirano, Teruyuki; Kuzuhara, Masayuki; Machida, Masahiro; Matsuo, Taro; Nagata, Tetsuya; Onuki, Hirohi; Ogihara, Masahiro; Takami, Hideki; Takato, Naruhisa; Takahashi, Yasuhiro H.; Tachinami, Chihiro; Terada, Hiroshi; Kawahara, Hajime; Yamamuro, Tomoyasu

    2014-07-01

    We report the current status of the Infrared Doppler (IRD) instrument for the Subaru telescope, which aims at detecting Earth-like planets around nearby M darwfs via the radial velocity (RV) measurements. IRD is a fiber-fed, near infrared spectrometer which enables us to obtain high-resolution spectrum (R~70000) from 0.97 to 1.75 μm. We have been developing new technologies to achieve 1m/s RV measurement precision, including an original laser frequency comb as an extremely stable wavelength standard in the near infrared. To achieve ultimate thermal stability, very low thermal expansion ceramic is used for most of the optical components including the optical bench.

  14. Repackaging and characterizing of a HgCdTe CMOS infrared camera for the New Solar Telescope

    NASA Astrophysics Data System (ADS)

    Cao, Wenda; Coulter, Roy; Gorceix, Nicolas; Goode, Philip R.

    2010-07-01

    The 1.6-meter New Solar Telescope (NST) is currently the world's largest aperture solar telescope. The NST is newly built at Big Bear Solar Observatory (BBSO). Among other instruments, the NST is equipped with several focal plane instruments operating in the near infrared (NIR). In order to satisfy the diverse observational requirements of these scientific instruments, a 1024 × 1024 HgCdTe TCM8600 CMOS camera manufactured by Rockwell Scientific Company has been repackaged and upgraded at Infrared Laboratories Inc. A new ND-5 dewar was designed to house the TCM8600 array with a low background filter wheel, inverted operation and at least 12 hours of hold time between fills. The repackaged camera will be used for high-resolution NIR photometry at the NST Nasmyth focus on the telescope and high-precision NIR spectro-polarimetry in the NST Coudé Lab below. In March 2010, this repackaged camera was characterized in the Coudé Lab at BBSO. This paper presents the design of new dewar, the detailed process of repackaging and characterizing the camera, and a series of test results.

  15. Investigation Development Plan for Reflight of the Small Helium-cooled Infrared Telescope Experiment. Volume 1: Investigation and Technical/management

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The Infrared Telescope (IRT) is designed to survey extended celestial sources of infrared radiation between 4 and 120 micrometers wavelength. It will provide data regarding Space Shuttle induced environmental contamination and the zodical light. And, it will provide experience in the management of large volumes of superfluid helium in the space environment.

  16. The SAPHIRA Near-Infrared Avalanche Photodiode Array: Telescope Deployments and Future Developments

    NASA Astrophysics Data System (ADS)

    Atkinson, Dani Eleanor; Hall, Donald; Baranec, Christoph

    2015-01-01

    We present our recent achievements of the Selex SAPHIRA APD arrays, which this year have seen deployment at three different telescopes, most notably demonstrating tip-tilt wavefront sensing in conjunction with the Palomar 1.5-m Telescope's Robo-AO system. A cooperative effort to provide enhanced speckle nulling capability to the SCExAO instrument on the Subaru telescope is also underway. We present the progress and development timeframe for the SAPHIRA and expected future applications, including targets and observational parameter space we expect the detectors to open to the astronomical community.

  17. Dual-Telescope Multi-Channel Thermal-Infrared Radiometer for Outer Planet Fly-By Missions

    NASA Technical Reports Server (NTRS)

    Aslam, Shahid; Amato, Michael; Bowles, Neil; Calcutt, Simon; Hewagama, Tilak; Howard, Joseph; Howett, Carly; Hsieh, Wen-Ting; Hurford, Terry; Hurley, Jane; Jennings, Donald E.; Lakew, Brook; Loeffler, Mark; Nicoletti, Anthony; Nixon, Conor A.; Quilligan, Gerard; West, Garrett

    2016-01-01

    The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8-200 microns, in five spectral pass bands, for outer planet fly-by missions is described. The dual- telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field- of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

  18. Dual-telescope multi-channel thermal-infrared radiometer for outer planet fly-by missions

    NASA Astrophysics Data System (ADS)

    Aslam, Shahid; Amato, Michael; Bowles, Neil; Calcutt, Simon; Hewagama, Tilak; Howard, Joseph; Howett, Carly; Hsieh, Wen-Ting; Hurford, Terry; Hurley, Jane; Irwin, Patrick; Jennings, Donald E.; Kessler, Ernst; Lakew, Brook; Loeffler, Mark; Mellon, Michael; Nicoletti, Anthony; Nixon, Conor A.; Putzig, Nathaniel; Quilligan, Gerard; Rathbun, Julie; Segura, Marcia; Spencer, John; Spitale, Joseph; West, Garrett

    2016-11-01

    The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8-200 μm, in five spectral pass bands, for outer planet fly-by missions is described. The dual-telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field-of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

  19. 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

  20. 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

  1. 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.

  2. Building the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2012-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. JWST will make progress In almost every area of astronomy, from the first galaxies to form in the early universe to exoplanets and Solar System objects. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Near-Infrared Imager and Slitless Spectrograph will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. The observatory Is confirmed for launch in 2018; the design is complete and it is in its construction phase. Innovations that make JWST possible include large-area low-noise infrared detectors, cryogenic ASICs, a MEMS micro-shutter array providing multi-object spectroscopy, a non-redundant mask for interferometric coronagraphy and diffraction-limited segmented beryllium mirrors with active wavefront sensing and control. Recent progress includes the completion of the mirrors, the delivery of the first flight instruments and the start of the integration and test phase.

  3. Cryogenically Cooled Infrared Interferometric Spectrometers

    DTIC Science & Technology

    1981-06-30

    Robert Jones Director Chief Naval Research Laboratory US Army Research Office Washington, DC 20375 P.O. Box 12211 Attn: Code 7127 C.Y.Johnson Triangle...Park, NC 27709 Attn: Robert Mace Director Naval Research Laboratory Commander Washington, DC 20375 Naval Oceans Systems Center Attn: Code 7700...Commander ASD Naval Surface W3apons Center WPAPB, OH 45433 White Oaks, Silver Spring .WD 20910 Attn: ASD-YH-EX Attn: Technical Library Lt Col Robert

  4. PROBING THE INTERSTELLAR MEDIUM OF z {approx} 1 ULTRALUMINOUS INFRARED GALAXIES THROUGH INTERFEROMETRIC OBSERVATIONS OF CO AND SPITZER MID-INFRARED SPECTROSCOPY

    SciTech Connect

    Pope, Alexandra; Kirkpatrick, Allison; Wagg, Jeff; Frayer, David; Armus, Lee; Chary, Ranga-Ram; Desai, Vandana; Daddi, Emanuele; Elbaz, David; Gabor, Jared

    2013-08-01

    We explore the relationship between gas, dust, and star formation in a sample of 12 ultraluminous infrared galaxies (ULIRGs) at high-redshift compared to a similar sample of local galaxies. We present new CO observations and/or Spitzer mid-IR spectroscopy for six 70 {mu}m selected galaxies at z {approx} 1 in order to quantify the properties of the molecular gas reservoir, the contribution of an active galactic nucleus (AGN) to the mid-IR luminosity, and the star formation efficiency (SFE = L{sub IR}/L{sup '}{sub CO}). The mid-IR spectra show strong polycyclic aromatic hydrocarbon (PAH) emission, and our spectral decomposition suggests that the AGN makes a minimal contribution (<25%) to the mid-IR luminosity. The 70 {mu}m selected ULIRGs, which we find to be spectroscopic close pairs, are observed to have high SFE, similar to local ULIRGs and high-redshift submillimeter galaxies, consistent with enhanced IR luminosity due to an ongoing major merger. Combined with existing observations of local and high-redshift ULIRGs, we further compare the PAH, IR, and CO luminosities. We show that the ratio L{sub PAH,6.2}/L{sub IR} decreases with increasing IR luminosity for both local and high-redshift galaxies, but the trend for high-redshift galaxies is shifted to higher IR luminosities; the average L{sub PAH,6.2}/L{sub IR} ratio at a given L{sub IR} is {approx}3 times higher at high-redshift. When we normalize by the molecular gas, we find this trend to be uniform for galaxies at all redshifts and that the molecular gas is correlated with the PAH dust emission. The similar trends seen in the [C II] to molecular gas ratios in other studies suggests that PAH emission, like [C II], continues to be a good tracer of photodissociation regions even at high-redshift. Together the CO, PAH, and far-IR fine structure lines should be useful for constraining the interstellar medium conditions in high-redshift galaxies.

  5. Test results of Spacelab 2 infrared telescope focal plane. [photoconductive detector fabrication and JFET transimpedance amplifier design

    NASA Technical Reports Server (NTRS)

    Young, E. T.; Rieke, G. H.; Gautier, T. N.; Hoffmann, W. F.; Low, F. J.; Poteet, W.; Fazio, G. G.; Koch, D.; Traub, W. A.; Urban, E. W.

    1981-01-01

    The small helium cooled infrared telescope for Spacelab 2 is designed for sensitive mapping of extended, low-surface-brightness celestial sources as well as highly sensitive investigations of the shuttle contamination environment (FPA) for this mission is described as well as the design for a thermally isolated, self-heated J-FET transimpedance amplifier. This amplifier is Johnson noise limited for feedback resistances from less than 10 to the 8th power Omega to greater than 2 x 10 to the 10th power Omega at T = 4.2K. Work on the focal plane array is complete. Performance testing for qualification of the flight hardware is discussed, and results are presented. All infrared data channels are measured to be background limited by the expected level of zodiacal emission.

  6. BETTII: The Balloon Experimental Twin Telescope for Infrared Interferometry (Phase 2a)- High Angular Resolution Astronomy at Far-Infrared Wavelengths

    NASA Astrophysics Data System (ADS)

    Rinehart, Stephen

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an eight-meter baseline far-infrared interferometer to fly on a high altitude balloon. The combination of the long baseline with a double-Fourier instrument allows BETTII to simultaneously gain both spatial and spectral information; BETTII is designed for spatially-resolved spectroscopy. The unique data obtained with BETTII will be valuable for understanding how stars form within dense clusters, by isolating individual objects that are unresolved by previous space telescopes and my measuring their spectral energy distributions. BETTII will be also used in future flights to understand the processes in the cores of Active Galactic Nuclei. In addition to these scientific goals, BETTII serves as a major step towards achieving the vision of space-based interferometry. BETTII was first funded through the 2010 APRA program; last year, the proposal also fared well in the APRA review, but for programmatic reasons was only awarded one year of funding. With the current funding, we will complete the BETTII experiment and conduct a Commissioning Flight in August/September 2016. The effort proposed includes full analysis of data from the Commissioning Flight, which will help us determine the technical and scientific capabilities of the experiment. It also includes two science flights, one in each 2017 and 2018, with full data analysis being completed in 2019.

  7. Serviceable Large Low Cost/Mass Infrared 4 Kelvin Telescope Passively Cooled

    NASA Astrophysics Data System (ADS)

    Tenerelli, Domenick; Tolomeo, J.; Klavins, A.; Putnam, D.

    2012-05-01

    An innovative space telescope concept was studied for the New Millenium program for ST6. The telescope called a Dual Anamorphic Reflector Telescope (DART) features two single curvature monolith parabolic surfaces. The telescope system personifies simplicity which extrapolates to low cost and mass. We at Lockheed Martin have implemented this design in two large prototypes that demonstrate imaging in the IR without the use of corrective optics as well as demonstrate the mass scaling advantageous of this architecture. A serviceable deployment concept is described which will enable apertures greater than 10m with areal density less than 10 kg/m2 to be realized for space applications. Because of the overall simplicity of the architecture the instrument section is easily replaceable when new detector technology is developed. In addition the simplicity of the overall architecture allows the system to assembled on the International Space Station (ISS). Anti sun pointing, low conductance support structure and deployable sun shade made of multiple deployable shields in an open groove configuration maintains telescope temperatures near 4K with minimal gradients

  8. Photometry of Galactic and Extragalactic Far-Infrared Sources using the 91.5 cm Airborne Infrared Telescope

    NASA Technical Reports Server (NTRS)

    Harper, D. A.

    1996-01-01

    The objective of this grant was to construct a series of far infrared photometers, cameras, and supporting systems for use in astronomical observations in the Kuiper Airborne Observatory. The observations have included studies of galaxies, star formation regions, and objects within the Solar System.

  9. Experiment requirements document for reflight of the small helium-cooled infrared telescope experiment

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The four astronomical objectives addressed include: the measurement and mapping of extended low surface brightness infrared emission from the galaxy; the measurement of diffuse emission from intergalactic material and/or galaxies and quasi-stellar objects; the measurement of the zodiacal dust emission; and the measurement of a large number of discrete infrared sources.

  10. Optical design for the Narrow Field InfraRed Adaptive Optics System (NFIRAOS) Petite on the Thirty Meter Telescope

    SciTech Connect

    Bauman, B; Gavel, D; Dekany, R; Ellerbroek, B

    2005-08-02

    We describe an exploratory optical design for the Narrow Field InfraRed Adaptive Optics (AO) System (NFIRAOS) Petite, a proposed adaptive optics system for the Thirty Meter Telescope Project. NFIRAOS will feed infrared spectrograph and wide-field imaging instruments with a diffraction limited beam. The adaptive optics system will require multi-guidestar tomographic wavefront sensing and multi-conjugate AO correction. The NFIRAOS Petite design specifications include two small 60 mm diameter deformable mirrors (DM's) used in a woofer/tweeter or multiconjugate arrangement. At least one DM would be a micro-electromechanical system (MEMS) DM. The AO system would correct a 10 to 30 arcsec diameter science field as well as laser guide stars (LGS's) located within a 60 arcsec diameter field and low-order or tip/tilt natural guide stars (NGS's) within a 60 arcsec diameter field. The WFS's are located downstream of the DM's so that they can be operated in true closed-loop, which is not necessarily a given in extremely large telescope adaptive optics design. The WFS's include adjustable corrector elements which correct the static aberrations of the AO relay due to field position and LGS distance height.

  11. Dusty Disks, Diffuse Clouds, and Dim Suns: Galactic Science with the Infrared Spectrograph on the Spitzer Space Telescope

    NASA Technical Reports Server (NTRS)

    Roellig, T. L.; Watson, D. M.; Uchida, K. I.; Forrest, W. J.; VanCleve, J. E.; Herter, T. L.; Sloan, G. C.; Furlan, E.; Wilson, J. C.; Bernard-Salas, J.

    2004-01-01

    The Infrared Spectrograph (IRS) on the Spitzer Space Telescope has now been in routine science operations since Dec. 14,2003. The IRS Science Team has used a portion of their guaranteed time to pursue three major science themes in galactic astronomy: the evolution of protostellar disks and debris disks; the composition and evolution of diffuse matter and clouds in the interstellar medium; and the composition and structure of brown dwarfs and low-mass main-sequence stars. We report here on the results from the first five months of IRS observations in these programs. Full IRS Spectra have already been obtained for large samples of YSO/protoplanetary disks in the Taurus and TW Hya associations, and or debris disks around main-sequence stars, in which many aspects of the evolution of planetary systems can be addressed for the first time. As anticipated, the mid-infrared IRS observations of brown dwarfs have yielded important new information about their atmospheres, including the identification of NH3 and measurements of new methane features. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407. Support for this work was provided by NASA's Office of Space Science.

  12. An optical design of the wide-field imaging and multi-object spectrograph for an Antarctic infrared telescope

    NASA Astrophysics Data System (ADS)

    Ichikawa, Takashi; Obata, Tomokazu

    2016-08-01

    A design of the wide-field infrared camera (AIRC) for Antarctic 2.5m infrared telescope (AIRT) is presented. The off-axis design provides a 7'.5 ×7'. 5 field of view with 0".22 pixel-1 in the wavelength range of 1 to 5 μm for the simultaneous three-color bands using cooled optics and three 2048×2048 InSb focal plane arrays. Good image quality is obtained over the entire field of view with practically no chromatic aberration. The image size corresponds to the refraction limited for 2.5 m telescope at 2 μm and longer. To enjoy the stable atmosphere with extremely low perceptible water vapor (PWV), superb seeing quality, and the cadence of the polar winter at Dome Fuji on the Antarctic plateau, the camera will be dedicated to the transit observations of exoplanets. The function of a multi-object spectroscopic mode with low spectra resolution (R 50-100) will be added for the spectroscopic transit observation at 1-5 μm. The spectroscopic capability in the environment of extremely low PWV of Antarctica will be very effective for the study of the existence of water vapor in the atmosphere of super earths.

  13. Discovery and characterization of on-orbit degradation of the Visible Infrared Imaging Radiometer Suite (VIIRS) Rotating Telescope Assembly (RTA)

    NASA Astrophysics Data System (ADS)

    De Luccia, F.; Moyer, D.; Johnson, E.; Rausch, K.; Lei, N.; Chiang, K.; Xiong, X.; Fulbright, J.; Haas, E.; Iona, G.

    2012-09-01

    The Suomi National Polar-orbiting Partnership (NPP) satellite was launched on Oct. 28, 2011, and began the commissioning phase of several of its instruments shortly thereafter. One of these instruments, VIIRS, was found to exhibit a gradual but persistent decrease in the optical throughput of several bands, with the near-infrared bands being more affected than those in the visible. The rate of degradation quickly increased upon opening of the nadir door that permits the VIIRS telescope to view the earth. Simultaneously, a second instrument on NPP, the Solar Diffuser Stability Monitor (SDSM), was experiencing a similar decrease in response, leading the investigation team to suspect that the cause must be the result of some common contamination process. This paper will discuss a series of experiments that were performed to demonstrate that the VIIRS and SDSM response changes were due to separate causes, and which enabled the team to conclude that the VIIRS sensor degradation was the result of ultraviolet light exposure of the rotating telescope assembly. The root cause investigation of the telescope degradation will be addressed in a separate paper.

  14. STRAY An Interactive Program For The Computation Of Stray Radiation In Infrared Telescopes

    NASA Astrophysics Data System (ADS)

    Dinger, Ann S.

    1987-06-01

    STRAY has been developed to quickly but roughly model the amount of stray radiation reaching the focal plane of a well-baffled telescope. This radiation arises from the scattering and diffraction of the light of bright off-axis sources, such as the Sun, Earth and Moon, as well as the thermal emission of the telescope itself. A series of specular reflections, scatters and diffractions propagates this energy to the focal plane. The sum of the various paths yields the focal plane irradiance. The telescope may be of Cassegrain, Gregorian or Herschelian design, as well as prime focus. A two-section conical aperture shade is included, which may be sliced off at an angle to the optical axis. Data on Class 100, 300 and 500 mirror contaminations, as well as a number of clean mirrors, are available for BRDF calculations. The stray radiation signal accumulated after a series of telescope nods and/or chops against a time-varying background may also be evaluated. The user enters the nodding and chopping frequencies, the chopping amplitude and duty cycle, and the time rate-of-change of the off-axis angle or temperature.

  15. A Multi-Band Far-Infrared Survey with a Balloon-Borne Telescope. Final Report, 20 Nov. 1972 - 19 Feb. 1978. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Jacobson, M. R.; Harwit, M.; Frederick, C.; Ward, D. B.; Melnick, G.; Stasavage, G.

    1978-01-01

    Nine additional radiation sources, above a 3-sigma confidence level of 1300 Jy, were identified at 100 microns by far infrared photometry of the galactic plane using a 0.4 meter aperture, liquid helium cooled, multichannel far infrared balloon-borne telescope. The instrument is described, including its electronics, pointing and suspension systems, and ground support equipment. Testing procedures and flight staging are discussed along with the reduction and analysis of the data acquired. The history of infrared astronomy is reviewed. General infrared techniques and the concerns of balloon astronomers are explored.

  16. 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.

  17. Solar System Studies in the Infrared with the Spitzer Space Telescope

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Stansberry, J. A.; Cleve, J. Van; Burgdorf, M. J.; Fernandez, Y. R.; Meadows, V. S.; Reach, W. T.

    2004-01-01

    The Spitzer Space Telescope, formerly known as SIRTF, is a cryogenic telescope (85 cm diameter) operating in a heliocentric orbit trailing the Earth. Its three instruments provide capabilities for spectroscopy, wide-field and small-field imaging at many wavelengths in the range 3.5-160 microns. Observations to be executed in the first two years in programs defined by the Guaranteed Time Observer (GTO) group (the authors of this presentation) consist of photometry, spectroscopy, and radiometry of many Solar System objects, including Titan and other satellites of the outer planets, Pluto, Centaurs, trans-Neptunian objects, comers, asteroids, Uranus, and Neptune. At the time of the preparation of this abstract, some preliminary observations have been made, but the final calibration and reduction of the data are still in progress. The latest results of the Solar System investigations will be presented here.

  18. Optimised radiative cooling of infrared space telescopes and applications to possible missions

    NASA Technical Reports Server (NTRS)

    Hawarden, T. G.; Cummings, R. O.; Telesco, C. M.; Thronson, H. A., Jr.

    1992-01-01

    Simple guidelines are presented for designing radiatively cooled space telescopes that must reach low temperatures. The limits achievable by such means are explored and secondary issues such as the on-orbit cooling time are examined. Results to date from a program of more detailed model simulations are summarized. These indicate that radiative cooling can indeed lower the temperatures of large-aperture telescopes sufficiently to make the technique of great interest for future IR space missions, while retaining advantages of size and duration, and can attain such low temperatures in quite reasonable times. Possible missions of this type are outlined, including the Edison proposal, the Japanese SMIRT survey mission, and an intermediate-size ESA/NASA mission.

  19. Balloon-borne three-meter telescope for far-infrared and submillimeter astronomy

    NASA Technical Reports Server (NTRS)

    Fazio, Giovanni G.

    1986-01-01

    The study and revision of the gimbal design of the Three-Meter Balloon Borne Telescope (TMBBT) is discussed. Efforts were made to eliminate the alignment and limited rotation problems inherent in the flex-pivot design. A new design using ball bearings to replace the flex-pivots was designed and its performance analyzed. An error analysis for the entire gondola pointing system was also prepared.

  20. Prime Focus Spectrograph (PFS): A Very Wide-Field, Massively Multi-Object, Optical and Near-Infrared Fiber-Fed Spectrograph on the Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Tamura, N.; PFS Collaboration

    2016-10-01

    PFS (Prime Focus Spectrograph), a next generation facility instrument on the Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared fiber spectrograph: 2400 reconfigurable fibers are distributed in the 1.3 deg. field of view at the prime focus of the Subaru Telescope. The spectrograph system has blue, red, and near-infrared cameras to simultaneously observe spectra from 380 nm to 1260 nm in one exposure. The project is now entering the construction phase, aiming at starting system integration and commissioning in 2017-2018, and science operation in 2019.

  1. Infrared-faint radio sources are at high redshifts. Spectroscopic redshift determination of infrared-faint radio sources using the Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Herzog, A.; Middelberg, E.; Norris, R. P.; Sharp, R.; Spitler, L. R.; Parker, Q. A.

    2014-07-01

    Context. Infrared-faint radio sources (IFRS) are characterised by relatively high radio flux densities and associated faint or even absent infrared and optical counterparts. The resulting extremely high radio-to-infrared flux density ratios up to several thousands were previously known only for high-redshift radio galaxies (HzRGs), suggesting a link between the two classes of object. However, the optical and infrared faintness of IFRS makes their study difficult. Prior to this work, no redshift was known for any IFRS in the Australia Telescope Large Area Survey (ATLAS) fields which would help to put IFRS in the context of other classes of object, especially of HzRGs. Aims: This work aims at measuring the first redshifts of IFRS in the ATLAS fields. Furthermore, we test the hypothesis that IFRS are similar to HzRGs, that they are higher-redshift or dust-obscured versions of these massive galaxies. Methods: A sample of IFRS was spectroscopically observed using the Focal Reducer and Low Dispersion Spectrograph 2 (FORS2) at the Very Large Telescope (VLT). The data were calibrated based on the Image Reduction and Analysis Facility (IRAF) and redshifts extracted from the final spectra, where possible. This information was then used to calculate rest-frame luminosities, and to perform the first spectral energy distribution modelling of IFRS based on redshifts. Results: We found redshifts of 1.84, 2.13, and 2.76, for three IFRS, confirming the suggested high-redshift character of this class of object. These redshifts and the resulting luminosities show IFRS to be similar to HzRGs, supporting our hypothesis. We found further evidence that fainter IFRS are at even higher redshifts. Conclusions: Considering the similarities between IFRS and HzRGs substantiated in this work, the detection of IFRS, which have a significantly higher sky density than HzRGs, increases the number of active galactic nuclei in the early universe and adds to the problems of explaining the formation of

  2. IRAN: Interferometric Remapped Array Nulling

    NASA Astrophysics Data System (ADS)

    Aristidi, E.; Vakili, F.; Schutz, A.; Lanteri, H.; Abe, L.; Belu, A.; Gori, P. M.; Lardière, O.; Lopez, B.; Menut, J. L.; Patru, F.

    IRAN is a method of beam-combination in the hypertelescope imaging technique recently introduced by Labeyrie in optical interferometry. We propose to observe the interferometric image in the pupil plane, performing multi-axial pupil plane interferometry. Imaging is performed in a combined pupil-plane where the point-source intensity distribution (PSID) tends towards a pseudo Airy disc for a sufficiently large number of telescopes. The image is concentrated into the limited support of the output pupil of the individual telescopes, in which the object-image convolution relation is conserved. Specific deconvolution algorithms have been developped for IRAN hypertelescope imagery, based upon Lucy-like iterative techniques. We show that the classical (image plane) and IRAN (pupil plane) hypertelescope imaging techniques are equivalent if one uses optical fibers for beam transportation. An application to the VLT/VIDA concept is presented.

  3. The mid-infrared instrument for the James Webb Space Telescope: performance and operation of the Low-Resolution Spectrometer

    NASA Astrophysics Data System (ADS)

    Kendrew, Sarah; Scheithauer, Silvia; Bouchet, Patrice; Amiaux, Jerome; Azzollini, Ruymán.; Bouwman, Jeroen; Chen, Christine; Dubreuil, Didier; Fischer, Sebastian; Fox, Ori D.; Glasse, Alistair; Gordon, Karl; Greene, Tom; Hines, Dean C.; Lagage, Pierre-Olivier; Lahuis, Fred; Ronayette, Samuel; Wright, David; Wright, Gillian S.

    2016-07-01

    We describe here the performance and operational concept for the Low Resolution Spectrometer (LRS) of the mid-infrared instrument (MIRI) for the James Webb Space Telescope. The LRS will provide R˜100 slit and slitless spectroscopy from 5 to 12 micron, and its design is optimised for observations of compact sources, such as exoplanet host stars. We provide here an overview of the design of the LRS, and its performance as measured during extensive test campaigns, examining in particular the delivered image quality, dispersion, and resolving power, as well as spectrophotometric performance. The instrument also includes a slitless spectroscopy mode, which is optimally suited for transit spectroscopy of exoplanet atmospheres. We provide an overview of the operational procedures and the differences ahead of the JWST launch in 2018.

  4. Optical design of MEMS-based infrared multi-object spectrograph concept for the Gemini South Telescope

    NASA Astrophysics Data System (ADS)

    Chen, Shaojie; Sivanandam, Suresh; Moon, Dae-Sik

    2016-08-01

    We discuss the optical design of an infrared multi-object spectrograph (MOS) concept that is designed to take advantage of the multi-conjugate adaptive optics (MCAO) corrected field at the Gemini South telescope. This design employs a unique, cryogenic MEMS-based focal plane mask to select target objects for spectroscopy by utilizing the Micro-Shutter Array (MSA) technology originally developed for the Near Infrared Spectrometer (NIRSpec) of the James Webb Space Telescope (JWST). The optical design is based on all spherical refractive optics, which serves both imaging and spectroscopic modes across the wavelength range of 0.9-2.5 μm. The optical system consists of a reimaging system, MSA, collimator, volume phase holographic (VPH) grisms, and spectrograph camera optics. The VPH grisms, which are VPH gratings sandwiched between two prisms, provide high dispersing efficiencies, and a set of several VPH grisms provide the broad spectral coverage at high throughputs. The imaging mode is implemented by removing the MSA and the dispersing unit out of the beam. We optimize both the imaging and spectrographic modes simultaneously, while paying special attention to the performance of the pupil imaging at the cold stop. Our current design provides a 1' ♢ 1' and a 0.5' ♢ 1' field of views for imaging and spectroscopic modes, respectively, on a 2048 × 2048 pixel HAWAII-2RG detector array. The spectrograph's slit width and spectral resolving power are 0.18'' and 3,000, respectively, and spectra of up to 100 objects can be obtained simultaneously. We present the overall results of simulated performance using optical model we designed.

  5. 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.

  6. The Lower Main Sequence of ω Centauri from Deep Hubble Space Telescope NICMOS Near-Infrared Observations

    NASA Astrophysics Data System (ADS)

    Pulone, Luigi; De Marchi, Guido; Paresce, Francesco; Allard, France

    1998-01-01

    A 20" × 20" field located ~7' from the center of the massive galactic globular cluster ω Centauri (NGC 5139) was observed by the NIC2 camera of the Near-Infrared Camera and Multiobject Spectrometer on board the Hubble Space Telescope (HST) through the F110W and F160W broadband filters centered at 1.1 and 1.6 μm for a total of 3000 and 4000 s for the two filters, respectively. Standard photometric analysis of the resulting images yields 340 stars with a signal above a 10 σ threshold in both filters, covering the range of HST m160 magnitudes between 20 and 26, the deepest probe yet of a globular cluster in this wavelength region. These objects form a well-defined sequence in the m160 versus m110-m160 plane that is consistent with the theoretical near-IR color-magnitude diagram expected from recent low-mass stellar model calculations. The resulting stellar luminosity function increases steadily with increasing magnitude up to a peak at m160~=25, where it turns over and drops slowly down to the detection limit set by the incompleteness limit of 60% at m160~=26. With the theoretical mass-luminosity relationship that provides the best fit to the IR color-magnitude diagram, we obtain an excellent fit to the observed luminosity function down to a mass of ~0.2 Msolar with a power-law mass function having a slope of α=-1. Based on observations 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., for NASA under contract NAS5-26555.

  7. Thermal study of payload module for the next-generation infrared space telescope SPICA in risk mitigation phase

    NASA Astrophysics Data System (ADS)

    Shinozaki, Keisuke; Sato, Yoichi; Sawada, Kenichiro; Ando, Makiko; Sugita, Hiroyuki; Yamawaki, Toshihiro; Mizutani, Tadahiro; Komatsu, Keiji; Nakagawa, Takao; Murakami, Hiroshi; Matsuhara, Hideo; Takada, Makoto; Takai, Shigeki; Okabayashi, Akinobu; Tsunematsu, Shoji; Kanao, Kenichi; Narasaki, Katsuhiro

    2014-11-01

    SPace Infrared telescope for Cosmology and Astrophysics (SPICA) is a pre-project of JAXA in collaboration with ESA to be launched around 2020. The SPICA is transferred into a halo orbit around the second Lagrangian point (L2) in the Sun-Earth system, which enables us to use effective radiant cooling in combination with mechanical cooling system in order to cool a 3 m large IR telescope below 6 K. At a present, a conceptional study of SPICA is underway to assess and mitigate mission's risks; the thermal study for the risk mitigation sets a goal of a 25% margin on cooling power of 4 K/1 K temperature regions, a 25% margin on the heat load from Focal Plane Instruments (FPIs) at intermediated temperature region, to enhance the reliability of the mechanical cooler system, and to enhance feasibility of ground tests. Thermal property measurements of FRP materials are also important. This paper introduces details of the thermal design study for risk mitigation, including development of the truss separation mechanism, the cryogenic radiator, mechanical cooler system, and thermal property measurements of materials.

  8. Wide-Field InfraRed Survey Telescope (WFIRST) Mission and Synergies with LISA and LIGO-Virgo

    NASA Technical Reports Server (NTRS)

    Gehrels, N.; Spergel, D.

    2015-01-01

    The Wide-Field InfraRed Survey Telescope (WFIRST) is a NASA space mission in study for launch in 2024. It has a 2.4 m telescope, wide-field IR instrument operating in the 0.7 - 2.0 micron range and an exoplanet imaging coronagraph instrument operating in the 400 - 1000 nm range. The observatory will perform galaxy surveys over thousands of square degrees to J=27 AB for dark energy weak lensing and baryon acoustic oscillation measurements and will monitor a few square degrees for dark energy SN Ia studies. It will perform microlensing observations of the galactic bulge for an exoplanet census and direct imaging observations of nearby exoplanets with a pathfinder coronagraph. The mission will have a robust and wellfunded guest observer program for 25% of the observing time. WFIRST will be a powerful tool for time domain astronomy and for coordinated observations with gravitational wave experiments. Gravitational wave events produced by mergers of nearby binary neutron stars (LIGO-Virgo) or extragalactic supermassive black hole binaries (LISA) will produce electromagnetic radiation that WFIRST can observe.

  9. Wide-Field InfraRed Survey Telescope (WFIRST) Mission and Synergies with LISA and LIGO-Virgo

    NASA Astrophysics Data System (ADS)

    Gehrels, N.; Spergel, D.; WFIRST SDT Project

    2015-05-01

    The Wide-Field InfraRed Survey Telescope (WFIRST) is a NASA space mission in study for launch in 2024. It has a 2.4 m telescope, wide-field IR instrument operating in the 0.7 - 2.0 micron range and an exoplanet imaging coronagraph instrument operating in the 400 - 1000 nm range. The observatory will perform galaxy surveys over thousands of square degrees to J=27 AB for dark energy weak lensing and baryon acoustic oscillation measurements and will monitor a few square degrees for dark energy SN Ia studies. It will perform microlensing observations of the galactic bulge for an exoplanet census and direct imaging observations of nearby exoplanets with a pathfinder coronagraph. The mission will have a robust and well- funded guest observer program for 25% of the observing time. WFIRST will be a powerful tool for time domain astronomy and for coordinated observations with gravitational wave experiments. Gravitational wave events produced by mergers of nearby binary neutron stars (LIGO-Virgo) or extragalactic supermassive black hole binaries (LISA) will produce electromagnetic radiation that WFIRST can observe.

  10. Catching the fish - Constraining stellar parameters for TX Piscium using spectro-interferometric observations

    NASA Astrophysics Data System (ADS)

    Klotz, D.; Paladini, C.; Hron, J.; Aringer, B.; Sacuto, S.; Marigo, P.; Verhoelst, T.

    2013-02-01

    Context. Stellar parameter determination is a challenging task when dealing with galactic giant stars. The combination of different investigation techniques has proven to be a promising approach. Aims: We analyse archive spectra obtained with the Short Wavelength Spectrometer (SWS) onboard ISO, and new interferometric observations from the Very Large Telescope MID-infrared Interferometric instrument (VLTI/MIDI) of a very well studied carbon-rich giant: TX Psc. The aim of this work is to determine stellar parameters using spectroscopy and interferometry. Methods: The observations are used to constrain the model atmosphere, and eventually the stellar evolutionary model in the region where the tracks map the beginning of the carbon star sequence. Two different approaches are used to determine stellar parameters: (i) the "classic" interferometric approach where the effective temperature is fixed by using the angular diameter in the N-band (from interferometry) and the apparent bolometric magnitude; (ii) parameters are obtained by fitting a grid of state-of-the-art hydrostatic models to spectroscopic and interferometric observations. Results: We find good agreement between the parameters of the two methods. The effective temperature and luminosity clearly place TX Psc in the carbon-rich AGB star domain in the H-R-diagram. Current evolutionary tracks suggest that TX Psc became a C-star just recently, which means that the star is still in a "quiet" phase compared to the subsequent strong-wind regime. This agrees with the C/O ratio being only slightly greater than one. Based on observations made with ESO telescopes at Paranal Observatory under program IDs 74.D-0601, 60.A-9224, 77.C-0440, 60.A-9006, 78.D-0112, 84.D-0805.

  11. Optical design of a near-infrared imaging spectropolarimeter for the Advanced Technology Solar Telescope

    NASA Astrophysics Data System (ADS)

    Greco, Vincenzo; Cavallini, Fabio

    2013-06-01

    In designing the optics of an imaging multi-etalon spectropolarimeter as a post-focus instrument for the Advanced Technology Solar Telescope (ATST), many constraints must be considered. Among these are the large entrance pupil diameter of the telescope (4 m), the demanded large field of view (≥90 arc sec), high spectral resolving power (≥200,000), and limited field-dependent blue-shift of the instrumental profile [≤3 full width at half maximum (FWHM)], which require Fabry-Perot interferometers of large diameter (≥200 mm), lighted by highly collimated beams. This implies large optical elements and long optical paths. Moreover, to use interference pre-filters with a relatively small diameter (≤70 mm) and placed between the interferometers to reduce the inter-reflections in axial-mount, a "pupil adapter" must be included with a further increase of the optical path length. Although a multi-etalon spectropolarimeter works in quasi-monochromatic light, the Fraunhofer lines of interest cover a wide range of wavelengths (850 to 1650 nm), which demands a good chromatic aberration control. A low instrumental polarization (≤0.5%) is also required to allow a high polarimetric precision. Finally, some secondary optical paths are required to perform the initial instrumental setup and to secure the best instrumental performances. A diffraction-limited optical solution for ATST is described that fulfills all the above requirements in a relative small volume.

  12. Study of alternate optical and fine guidance sensor designs for the space infrared telescope facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Wissinger, A.; Steir, M.; Mcfarlane, M.; Fuschetto, A.

    1984-01-01

    A unique optical design was developed that compensates for the coma degraded images caused by field chopping in SIRTF. The conic constants of a Cassegrain telescope were altered to compensate for the coma induced by the secondary mirror tilt. The modulation transfer function is essentially independent of secondary mirror tilt, and diffraction limited image quality is maintained over a several arcminute field during chopping. With an untilted secondary mirror, the coma compensated (CC) design has a smaller field than the unchopped Ritchey-Chretien design; but use of relay optics, such as the inverted Cassegrain design developed for the fine guidance sensor (FGS), can increase the CC telescope's field size. A reactionless secondary mirror chopper mechanism that uses superconducting magnets was studied. The heart producing elements are confined to a reaction plate that is not directly viewed by the IR focal plane. A design was also developed for a low moment of inertia, reticulated HIP beryllium secondary mirror consistent with blank fabrication technology and optical finishing requirements.

  13. Hydrogen sulfide on Io - Evidence from telescopic and laboratory infrared spectra

    NASA Technical Reports Server (NTRS)

    Nash, Douglas B.; Howell, Robert R.

    1989-01-01

    Evidence is reported for hydrogen sulfide on Io's surface. An infrared band at 3.915 (+ or - 0.015) micrometers in several ground-based spectra of Io can be accounted for by reflectance from H2S frost deposited on or cocondensed with sulfur dioxide frost. Temporal variation in the occurrence and intensity of the band suggests that condensed H2S on Io's surface is transient, implying a similar variation of H2S abundance in Io's atmosphere.

  14. Optimal Merging of Point Sources Extracted from Spitzer Space Telescope Data in Multiple Infrared Passbands Versus Simple General Source Association

    NASA Astrophysics Data System (ADS)

    Laher, R. R.; Fowler, J. W.

    2008-08-01

    For collating point-source flux measurements derived from multiple infrared passbands of Spitzer-Space-Telescope data -- e.g., channels 1-4 of the Infrared Array Camera (IRAC) and channels 1-3 of the Multiband Imaging Photometer for Spitzer (MIPS) -- it is best to use the `bandmerge' software developed at the Spitzer Science Center rather than the relatively simple method of general source association (GSA). The former method uses both source positions and positional uncertainties to form a chi-squared statistic that can be thresholded for optimal matching, while the latter method finds nearest neighbors across bands that fall within a user-specified radius of the primary source. Our assertion is supported by our study of completeness (C) vs. reliability (R) for the two methods, which involved MIPS-24/IRAC-1 matches in the SWIRE Chandra Deep Field South. Both methods can achieve C = 98%, but with R=92.7% for GSA vs. R=97.4% for bandmerge. With almost a factor of three lower in unreliability (1-R), bandmerge is the clear winner of this comparison.

  15. The Mid-Infrared Instrument for the James Webb Space Telescope, II: Design and Build

    NASA Astrophysics Data System (ADS)

    Wright, G. S.; Wright, David; Goodson, G. B.; Rieke, G. H.; Aitink-Kroes, Gabby; Amiaux, J.; Aricha-Yanguas, Ana; Azzollini, Ruymán; Banks, Kimberly; Barrado-Navascues, D.; Belenguer-Davila, T.; Bloemmart, J. A. D. L.; Bouchet, Patrice; Brandl, B. R.; Colina, L.; Detre, Örs; Diaz-Catala, Eva; Eccleston, Paul; Friedman, Scott D.; García-Marín, Macarena; Güdel, Manuel; Glasse, Alistair; Glauser, Adrian M.; Greene, T. P.; Groezinger, Uli; Grundy, Tim; Hastings, Peter; Henning, Th.; Hofferbert, Ralph; Hunter, Faye; Jessen, N. C.; Justtanont, K.; Karnik, Avinash R.; Khorrami, Mori A.; Krause, Oliver; Labiano, Alvaro; Lagage, P.-O.; Langer, Ulrich; Lemke, Dietrich; Lim, Tanya; Lorenzo-Alvarez, Jose; Mazy, Emmanuel; McGowan, Norman; Meixner, M. E.; Morris, Nigel; Morrison, Jane E.; Müller, Friedrich; rgaard-Nielson, H.-U. Nø; Olofsson, Göran; O’Sullivan, Brian; Pel, J.-W.; Penanen, Konstantin; Petach, M. B.; Pye, J. P.; Ray, T. P.; Renotte, Etienne; Renouf, Ian; Ressler, M. E.; Samara-Ratna, Piyal; Scheithauer, Silvia; Schneider, Analyn; Shaughnessy, Bryan; Stevenson, Tim; Sukhatme, Kalyani; Swinyard, Bruce; Sykes, Jon; Thatcher, John; Tikkanen, Tuomo; van Dishoeck, E. F.; Waelkens, C.; Walker, Helen; Wells, Martyn; Zhender, Alex

    2015-07-01

    The Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) provides measurements over the wavelength range 5 to 28.5 microns. MIRI has, within a single 'package', four key scientific functions: photometric imaging, coronagraphy, single-source low-spectral resolving power (R ~ 100) spectroscopy, and medium-resolving power (R ~ 1500 to 3500) integral field spectroscopy. An associated cooler system maintains MIRI at its operating temperature of < 6.7 K. This paper describes the driving principles behind the design of MIRI, the primary design parameters, and their realization in terms of the 'as-built' instrument. It also describes the test program that led to delivery of the tested and calibrated Flight Model to NASA in 2012, and the confirmation after delivery of the key interface requirements.

  16. Space infrared telescope facility wide field and diffraction limited array camera (IRAC)

    NASA Technical Reports Server (NTRS)

    Fazio, G. G.

    1986-01-01

    IRAC focal plane detector technology was developed and studies of alternate focal plane configurations were supported. While any of the alternate focal planes under consideration would have a major impact on the Infrared Array Camera, it was possible to proceed with detector development and optical analysis research based on the proposed design since, to a large degree, the studies undertaken are generic to any SIRTF imaging instrument. Development of the proposed instrument was also important in a situation in which none of the alternate configurations has received the approval of the Science Working Group.

  17. The near-infrared spectrometer of the Observatoire du Mont megantic 1.6-m telescope

    NASA Astrophysics Data System (ADS)

    Nadeau, Daniel; Beland, Stephane; Doyon, Rene

    1987-12-01

    An infrared spectrometer based on a piezo-electrically scanned Fabry-Pérot interferometer is described. The instrument includes a remote-controlled offset guider, the Fabry-Pérot interferometer and associated optics, and a cryostat containing the cold optics, and InSb detector. In the present configuration the spectrometer can be used from 1.8 to 2.5 μm, but it can be modified for observations in the range from 1 to 5 μm. Line profiles of the H2 emission in Cepheus A obtained with this instrument are shown.

  18. Practical Issues Related to the Interferometric Imaging of Geosats

    DTIC Science & Technology

    2014-09-01

    telescope in the interferometer, and how this influences the amount of light coupled into a fiber and the observed interferometric visibility amplitude. We...geostationary satellites, optical interferometry imaging, telescope arrays 1. INTRODUCTION A critical gap in the Space Situational Awareness capability is the...55 milli arcsec), equivalent to the resolving power of a 3.6 m telescope observing at 800 nm. In order to obtain high-resolution (∼10 cm) ground based

  19. Antarctic Surveying Telescope (AST3-3) NIR camera for the Kunlun Infrared Sky Survey (KISS): thermal optimization and system performance

    NASA Astrophysics Data System (ADS)

    Zheng, Jessica R.; Lawrence, Jon; Content, Robert; Churilov, Vladimir; Zhang, Kaiyuan; Yuan, Xiangyan; Lu, Haiping

    2016-08-01

    The Antarctic survey telescope (AST 3-3) near infrared(NIR) camera is designed to conduct the Kunlun Infrared Sky Survey which will provide a comprehensive exploration of the time varying Universe in the near infrared. It is going to be located at Dome A, on the Antarctic plateau, one of the most unique low background sites at the Kdark band (2.4μm). Carefully designed thermal emission from the telescope and the Kdark camera is very important to realize background limited operation. We setup a scattering and thermal emission model of the whole system to optimize the camera performance. An exposure time calculator was also built to predict system performance.

  20. Thermal and cryogenic design study for space infrared telescope facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Urbach, A. R.; Kelly, T.; Poley, R.

    1984-01-01

    A study was conducted to determine the ability of an all superfluid helium design to meet the performance requirements of background limited to 200 micrometer, and a two year lifetime for a one meter class free flying infrared observatory. Both a 98 deg and 28.5 deg inclination orbits were examined, and aperture shade designs were developed for both orbits. A unique forebaffle cooling design significantly reduces the sensitivity to aperture heat loads. With certain restrictions on observing modes, the study determined that an all superfluid helium Dewar will meet the temperature and lifetime requirements. A dual cryogen SFHe/SH2 system was also investigated for the 28.5 deg orbit and found to provide a more constant forebaffle temperature but with only a slight improvement in lifetime.

  1. Mean angular diameters, distances, and pulsation modes of the classical Cepheids FF Aquilae and T Vulpeculae. CHARA/FLUOR near-infrared interferometric observations

    NASA Astrophysics Data System (ADS)

    Gallenne, A.; Kervella, P.; Mérand, A.; McAlister, H.; ten Brummelaar, T.; Coudé du Foresto, V.; Sturmann, J.; Sturmann, L.; Turner, N.; Farrington, C.; Goldfinger, P. J.

    2012-05-01

    We report the first angular diameter measurements of two classical Cepheids, FF Aql and T Vul, that we obtain using observations with the FLUOR instrument installed at the CHARA interferometric array. We derive average limb-darkened angular diameters of θLD = 0.878 ± 0.013 mas and θLD = 0.629 ± 0.013 mas, respectively, for FF Aql and T Vul. Combining these angular diameters with the HST-FGS trigonometric parallaxes leads to linear radii R = 33.6 ± 2.2 R⊙ and R = 35.6 ± 4.4 R⊙, respectively. The comparison with empirical and theoretical period-radius relations leads to the conclusion that these Cepheids are pulsating in their fundamental mode. The knowledge of this pulsation mode is of prime importance to calibrating the period-luminosity relation with a uniform sample of fundamental mode Cepheids.

  2. Large Binocular Telescope Observations of Europa Occulting Io's Volcanoes at 4.8 μm

    NASA Astrophysics Data System (ADS)

    Skrutskie, Michael F.; Conrad, Albert; Resnick, Aaron; Leisenring, Jarron; Hinz, Phil; de Pater, Imke; de Kleer, Katherine; Spencer, John; Skemer, Andrew; Woodward, Charles E.; Davies, Ashley Gerard; Defrére, Denis

    2015-11-01

    On 8 March 2015 Europa passed nearly centrally in front of Io. The Large Binocular Telescope observed this event in dual-aperture AO-corrected Fizeau interferometric imaging mode using the mid-infrared imager LMIRcam operating behind the Large Binocular Telescope Interferometer (LBTI) at a broadband wavelength of 4.8 μm (M-band). Occultation light curves generated from frames recorded every 123 milliseconds show that both Loki and Pele/Pillan were well resolved. Europa's center shifted by 2 kilometers relative to Io from frame-to-frame. The derived light curve for Loki is consistent with the double-lobed structure reported by Conrad et al. (2015) using direct interferometric imaging with LBTI.

  3. INFRARED NARROWBAND TOMOGRAPHY OF THE LOCAL STARBURST NGC 1569 WITH THE LARGE BINOCULAR TELESCOPE/LUCIFER

    SciTech Connect

    Pasquali, A.; Zibetti, S.; Brandner, W.; Rix, H.-W.; Laun, W.; Lehmitz, M.; Lenzen, R.; Mall, U.; Ageorges, N.; Buschkamp, P.; Gemperlein, H.; Hofmann, R.; Lederer, R.; Seifert, W.; Feiz, C.; Germeroth, A.; Mandel, H.; Juette, M.; Knierim, V.; Bik, A.

    2011-04-15

    We used the near-IR imager/spectrograph LUCIFER mounted on the Large Binocular Telescope to image, with subarcsecond seeing, the local dwarf starburst NGC 1569 in the JHK bands and He I 1.08 {mu}m, [Fe II] 1.64 {mu}m, and Br{gamma} narrowband filters. We obtained high-quality spatial maps of He I 1.08 {mu}m, [Fe II] 1.64 {mu}m, and Br{gamma} emission across the galaxy, and used them together with Hubble Space Telescope/Advanced Camera for Surveys images of NGC 1569 in the H{alpha} filter to derive the two-dimensional spatial map of the dust extinction and surface star formation rate (SFR) density. We show that dust extinction (as derived from the H{alpha}/Br{gamma} flux ratio) is rather patchy and, on average, higher in the northwest (NW) portion of the galaxy (E{sub g}(B - V) {approx_equal} 0.71 mag) than in the southeast (E{sub g}(B - V) {approx_equal} 0.57 mag). Similarly, the surface density of SFR (computed from either the dereddened H{alpha} or dereddened Br{gamma} image) peaks in the NW region of NGC 1569, reaching a value of about 4 x 10{sup -6} M{sub sun} yr{sup -1} pc{sup -2}. The total SFR as estimated from the integrated, dereddened H{alpha} (or, alternatively, Br{gamma}) luminosity is about 0.4 M{sub sun} yr{sup -1}, and the total supernova rate from the integrated, dereddened [Fe II] 1.64 {mu}m luminosity is about 0.005 yr{sup -1} (assuming a distance of 3.36 Mpc). The azimuthally averaged [Fe II] 1.64 {mu}m/Br{gamma} flux ratio is larger at the edges of the central, gas-deficient cavities (encompassing the superstar clusters A and B) and in the galaxy outskirts. If we interpret this line ratio as the ratio between the average past star formation (as traced by supernovae) and ongoing activity (represented by OB stars able to ionize the interstellar medium), it would then indicate that star formation has been quenched within the central cavities and lately triggered in a ring around them. The number of ionizing hydrogen and helium photons as computed

  4. GMTNIRS: progress toward the Giant Magellan Telescope near-infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Jaffe, Daniel T.; Barnes, Stuart; Brooks, Cynthia; Lee, Hanshin; Mace, Gregory; Pak, Soojong; Park, Byeong-Gon; Park, Chan

    2016-08-01

    GMTNIRS is a first-generation instrument for the Giant Magellan Telescope. It is a high-resolution spectrograph that will cover the 1.15-5.3 μm range in a single exposure with R=60,000 in the J, H, and K bands and R=85,000 in the L and M bands. It resides on the GMT's rotating instrument platform and employs the facility adaptive optics system. The GMTNIRS design is evolving in response to emerging science problems, particularly in the area of exoplanet atmospheres. Our design revisions also derive lessons from GMTNIRS' highly successful forerunner instrument, IGRINS. Technical changes also drive evolution of the design. It has proven impractical to manufacture 200mm long immersion gratings at the necessary precision. The success of primary mirror phasing efforts has removed the need for a very wide entrance slit that we would have needed to accommodate the Airy pattern of individual segments at the shortest operating wavelengths. The high efficiency of our double-side coated JWST grisms introduces the possibility of transmissive cross-dispersers at L and M. These changes move us toward a design with almost the same R as presented in our previous work but with a much more compact physical envelope. We will report on the optimization of the instrument design with these technical changes in mind. We are also producing the critical Si immersion gratings. The grating production is well under way and includes manufacture of H and K gratings and process development for the precision needed in the J band and for the manufacture of larger gratings for the L and M band. The development of GMTNIRS is on track with the results from IGRINS and the progress in the lab giving us substantial assurance that the new instrument can meet its performance goals.

  5. Hubble Space Telescope Observations of the Luminous IRAS Source FSC 10214+4724: A Gravitationally Lensed Infrared Quasar

    NASA Technical Reports Server (NTRS)

    Eisenhardt, Peter R.; Armus, Lee; Hogg, David W.; Soifer, B. T.; Neugebauer, G.; Werner, Michael W.

    1996-01-01

    With a redshift of 2.3, the IRAS source FSC 10214+4724 is apparently one of the most luminous objects known in the universe. We present an image of FSC 10214+4724 at 0.8 pm obtained with the Hubble Space Telescope (HST) WFPC2 Planetary Camera. The source appears as an unresolved (less then 0.06) arc 0.7 long, with significant substructure along its length. The center of curvature of the arc is located near an elliptical galaxy 1.18 to the north. An unresolved component 100 times fainter than the arc is clearly detected on the opposite side of this galaxy. The most straightforward interpretation is that FSC 10214+4724 is gravitationally lensed by the foreground elliptical galaxy, with the faint component a counter-image of the IRAS source. The brightness of the arc in the HST image is then magnified by approx. 100, and the intrinsic source diameter is approx. 0.0l (80 pc) at 0.25 microns rest wavelength. The bolometric luminosity is probably amplified by a smaller factor (approx. 30) as a result of the larger extent expected for the source in the far-infrared. A detailed lensing model is presented that reproduces the observed morphology and relative flux of the arc and counterimage and correctly predicts the position angle of the lensing galaxy. The model also predicts reasonable values for the velocity dispersion, mass, and mass-to-light ratio of the lensing galaxy for a wide range of galaxy redshifts. A redshift for the lensing galaxy of -0.9 is consistent with the measured surface brightness profile from the image, as well as with the galaxy's spectral energy distribution. The background lensed source has an intrinsic luminosity approx. 2 x 10(exp 13) L(solar mass) and remains a highly luminous quasar with an extremely large ratio of infrared to optical/ultraviolet luminosity.

  6. Micro-spec: an Integrated Direct-detection Spectrometer for Far-infrared Space Telescopes

    NASA Technical Reports Server (NTRS)

    Cataldo, Giuseppe; Hsieh, Wen-Ting; Huang, Wei-Chung; Moseley, S. Harvey; Stevenson, Thomas R.; Wollack, Edward J.

    2014-01-01

    The far-infrared and submillimeter portions of the electromagnetic spectrum provide a unique view of the astrophysical processes present in the early universe. Our ability to fully explore this rich spectral region has been limited, however, by the size and cost of the cryogenic spectrometers required to carry out such measurements.Micro-Spec (µ-Spec) is a high-sensitivity, direct-detection spectrometer concept working in the 450-1000 (micrometers) wavelength range which will enable a wide range of flight missions that would otherwise be challenging due tothe large size of current instruments with the required spectral resolution and sensitivity. The spectrometer design utilizes two internal antenna arrays, one for transmitting and one for receiving, superconducting microstrip transmission lines for power division and phase delay, and an array of microwave kinetic inductance detectors (MKIDs) to achieve these goals. The instrument will be integrated on a approximately 10 sq cm silicon chip and can therefore become an important capability under the low background conditions accessible via space and high-altitude borne platforms. In this paper, an optical design methodology for micro-Spec is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the maximization of the instrument resolving power and minimization of the RMS phase error on the instrument focal plane. This two-step optimization can generate geometrical configurations given specific requirements on spectrometer size, operating spectral range and performance.Two point designs with resolving power of 260 and 520 and an RMS phase error less than approximately 0.004 radians were developed for initial demonstration and will be the basis of future instruments with resolving power up to about 1200.

  7. HUBBLE SPACE TELESCOPE/NEAR-INFRARED CAMERA AND MULTI-OBJECT SPECTROMETER OBSERVATIONS OF THE GLIMPSE9 STELLAR CLUSTER

    SciTech Connect

    Messineo, Maria; Figer, Donald F.; Davies, Ben; Trombley, Christine; Kudritzki, R. P.; Rich, R. Michael; MacKenty, John

    2010-01-10

    We present Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer photometry, and low-resolution K-band spectra of the GLIMPSE9 stellar cluster. The newly obtained color-magnitude diagram shows a cluster sequence with H - K{sub S} = approx1 mag, indicating an interstellar extinction A{sub K{sub s}} = 1.6 +- 0.2 mag. The spectra of the three brightest stars show deep CO band heads, which indicate red supergiants with spectral type M1-M2. Two 09-B2 supergiants are also identified, which yield a spectrophotometric distance of 4.2 +- 0.4 kpc. Presuming that the population is coeval, we derive an age between 15 and 27 Myr, and a total cluster mass of 1600 +- 400 M{sub sun}, integrated down to 1 M{sub sun}. In the vicinity of GLIMPSE9 are several H II regions and supernova remnants, all of which (including GLIMPSE9) are probably associated with a giant molecular cloud (GMC) in the inner galaxy. GLIMPSE9 probably represents one episode of massive star formation in this GMC. We have identified several other candidate stellar clusters of the same complex.

  8. AGE SPREAD IN W3 MAIN: LARGE BINOCULAR TELESCOPE/LUCI NEAR-INFRARED SPECTROSCOPY OF THE MASSIVE STELLAR CONTENT

    SciTech Connect

    Bik, A.; Henning, Th.; Brandner, W.; Gouliermis, D. A.; Gennaro, M.; Rochau, B.; Beuther, H.; Kudryavtseva, N.; Stolte, A.; Pasquali, A.; Ageorges, N.; Seifert, W.; Wang, Y.

    2012-01-10

    We present near-infrared multi-object spectroscopy and JHK{sub s} imaging of the massive stellar content of the Galactic star-forming region W3 Main, obtained with LUCI at the Large Binocular Telescope. We confirm 15 OB stars in W3 Main and derive spectral types between O5V and B4V from their absorption line spectra. Three massive young stellar objects are identified by their emission line spectra and near-infrared excess. The color-color diagram of the detected sources allows a detailed investigation of the slope of the near-infrared extinction law toward W3 Main. Analysis of the Hertzsprung-Russell diagram suggests that the Nishiyama extinction law fits the stellar population of W3 Main best (E(J - H)/E(H - K{sub s}) = 1.76 and R{sub K{sub s}} = 1.44). From our spectrophotometric analysis of the massive stars and the nature of their surrounding H II regions, we derive the evolutionary sequence of W3 Main and we find evidence of an age spread of at least 2-3 Myr. While the most massive star (IRS2) is already evolved, indications for high-mass pre-main-sequence evolution are found for another star (IRS N1), deeply embedded in an ultracompact H II (UCH II) region, in line with the different evolutionary phases observed in the corresponding H II regions. We derive a stellar mass of W3 Main of (4 {+-} 1) Multiplication-Sign 10{sup 3} M{sub Sun} by extrapolating from the number of OB stars using a Kroupa initial mass function and correcting for our spectroscopic incompleteness. We have detected the photospheres of OB stars from the more evolved diffuse H II region to the much younger UCH II regions, suggesting that these stars have finished their formation and cleared away their circumstellar disks very fast. Only in the hyper-compact H II region (IRS5) do the early-type stars seem to be still surrounded by circumstellar material.

  9. Developing Wide-Field Spatio-Spectral Interferometry for Far-Infrared Space Applications

    NASA Technical Reports Server (NTRS)

    Leisawitz, David; Bolcar, Matthew R.; Lyon, Richard G.; Maher, Stephen F.; Memarsadeghi, Nargess; Rinehart, Stephen A.; Sinukoff, Evan J.

    2012-01-01

    Interferometry is an affordable way to bring the benefits of high resolution to space far-IR astrophysics. We summarize an ongoing effort to develop and learn the practical limitations of an interferometric technique that will enable the acquisition of high-resolution far-IR integral field spectroscopic data with a single instrument in a future space-based interferometer. This technique was central to the Space Infrared Interferometric Telescope (SPIRIT) and Submillimeter Probe of the Evolution of Cosmic Structure (SPECS) space mission design concepts, and it will first be used on the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). Our experimental approach combines data from a laboratory optical interferometer (the Wide-field Imaging Interferometry Testbed, WIIT), computational optical system modeling, and spatio-spectral synthesis algorithm development. We summarize recent experimental results and future plans.

  10. 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.

  11. 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.

  12. Modal Filters for Infrared Interferometry

    NASA Technical Reports Server (NTRS)

    Ksendzov, Alexander; MacDonald, Daniel R.; Soibel, Alexander

    2009-01-01

    Modal filters in the approximately equal to 10-micrometer spectral range have been implemented as planar dielectric waveguides in infrared interferometric applications such as searching for Earth-like planets. When looking for a small, dim object ("Earth") in close proximity to a large, bright object ("Sun"), the interferometric technique uses beams from two telescopes combined with a 180 phase shift in order to cancel the light from a brighter object. The interferometer baseline can be adjusted so that, at the same time, the light from the dimmer object arrives at the combiner in phase. This light can be detected and its infrared (IR) optical spectra can be studied. The cancellation of light from the "Sun" to approximately equal to 10(exp 6) is required; this is not possible without special devices-modal filters- that equalize the wavefronts arriving from the two telescopes. Currently, modal filters in the approximately equal to 10-micrometer spectral range are implemented as single- mode fibers. Using semiconductor technology, single-mode waveguides for use as modal filters were fabricated. Two designs were implemented: one using an InGaAs waveguide layer matched to an InP substrate, and one using InAlAs matched to an InP substrate. Photon Design software was used to design the waveguides, with the main feature all designs being single-mode operation in the 10.5- to 17-micrometer spectral range. Preliminary results show that the filter's rejection ratio is 26 dB.

  13. 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.

  14. The UK Infrared Telescope M 33 monitoring project - V. The star formation history across the galactic disc

    NASA Astrophysics Data System (ADS)

    Javadi, Atefeh; van Loon, Jacco Th.; Khosroshahi, Habib G.; Tabatabaei, Fatemeh; Hamedani Golshan, Roya; Rashidi, Maryam

    2017-01-01

    We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope of the Local Group spiral galaxy M 33 (Triangulum). On the basis of their variability, we have identified stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this fifth paper of the series, we construct the birth mass function and hence derive the star formation history across the galactic disc of M 33. The star formation rate has varied between ˜0.010 ± 0.001 (˜0.012 ± 0.007) and 0.060±0.005 (0.052±0.009) M⊙ yr-1 kpc-2 statistically (systematically) in the central square kiloparsec of M 33, comparable with the values derived previously with another camera. The total star formation rate in M 33 within a galactocentric radius of 14 kpc has varied between ˜0.110 ± 0.005 (˜0.174 ± 0.060) and ˜0.560 ± 0.028 (˜0.503 ± 0.100) M⊙ yr-1 statistically (systematically). We find evidence of two epochs during which the star formation rate was enhanced by a factor of a few - one that started ˜6 Gyr ago and lasted ˜3 Gyr and produced ≥71 per cent of the total mass in stars, and one ˜250 Myr ago that lasted ˜200 Myr and formed ≤13 per cent of the mass in stars. Radial star formation history profiles suggest that the inner disc of M 33 was formed in an inside-out formation scenario. The outskirts of the disc are dominated by the old population, which may be the result of dynamical effects over many Gyr. We find correspondence to spiral structure for all stars, but enhanced only for stars younger than ˜100 Myr; this suggests that the spiral arms are transient features and not a part of a global density wave potential.

  15. The Near-Infrared Camera on the James Webb Space Telescope: The Next Great Step in Exoplanet Research

    NASA Astrophysics Data System (ADS)

    Beichman, C.; Doyon, R.; Greene, T.; Hodapp, K.; Horner, S.; Krist, J.; McCarthy, D.; Meyer, M.; Rieke, M.; Stansberry, J.; Stauffer, J.; Trauger, J.; NIRCam Team

    2014-03-01

    The Near-Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST) offers revolutionary gains in sensitivity throughout the 1-5 mm region. NIRCam will enable great advances in all areas of astrophysics, from the composition of objects in our own Kuiper Belt and the physical properties of planets orbiting nearby stars to the formation of stars and the detection of the youngest galaxies in the Universe. NIRCam will make some of its most dramatic contributions in the field of exoplanets: • Coronagraphy at 3 and 5 mm offers a very stable Point Spread Function (PSF) outside of ~5 l/D, or ~300 mas at 3.5 mm, plus the great sensitivity possible with a cooled telescope in the low background of space. While large ground-based telescopes with Adaptive Optics can achieve smaller working angles, they will be hard-pressed to find planets as small as 1 MJup whereas simulations suggest NIRCam will be able to find planets as small as Saturn on orbits from 10 to a few 100 AU around nearby young stars. • The great stability of NIRCam photometry will enable precision observations of known transiting systems to determine the vertical structure of exoplanet atmospheres and to measure complete phase curves to study atmospheric circulation. The use of sub-array mode and defocused images produced by a weak lenses in the pupil wheel will permit observations of transit host stars as bright as K~4 mag. • NIRCam's grism mode will be used to obtain R~2000 spectra in the 3 - 5 mm region to investigate the composition and atmospheric structure of transiting planets with radii as small as that of Uranus and perhaps super-Earths with hydrogen rich atmospheres. The use of sub-array mode and high spectral resolution will permit observations of objects as bright as K~ 6 mag. Laboratory tests suggest that NIRCam's HgCdTe detectors will be able to achieve (spectro-)photometric precision better than 50 mmag consistent with these goals. • NIRCam grism spectroscopy will reveal the

  16. The Large Binocular Telescope's ARGOS ground-layer AO system

    NASA Astrophysics Data System (ADS)

    Hart, M.; Rabien, S.; Busoni, L.; Barl, L.; Bechmann, U.; Bonaglia, M.; Boose, Y.; Borelli, J.; Bluemchen, T.; Carbonaro, L.; Connot, C.; Deysenroth, M.; Davies, R.; Durney, O.; Elberich, M.; Ertl, T.; Esposito, S.; Gaessler, W.; Gasho, V.; Gemperlein, H.; Hubbard, P.; Kanneganti, S.; Kulas, M.; Newman, K.; Noenickx, J.; de Xivry, G.; Qirrenback, A.; Rademacher, M.; Schwab, C.; Storm, J.; Vaitheeswaran, V.; Weigelt, G.; Ziegleder, J.

    2011-09-01

    ARGOS, the laser-guided adaptive optics system for the Large Binocular Telescope (LBT), is now under construction at the telescope. By correcting atmospheric turbulence close to the telescope, the system is designed to deliver high resolution near infrared images over a field of 4 arc minute diameter. ARGOS is motivated by a successful prototype multi-laser guide star system on the 6.5 m MMT telescope, results from which are presented in this paper. At the LBT, each side of the twin 8.4 m aperture is being equipped with three Rayleigh laser guide stars derived from six 18 W pulsed green lasers and projected into two triangular constellations matching the size of the corrected field. The returning light is to be detected by wavefront sensors that are range gated within the seeinglimited depth of focus of the telescope. Wavefront correction will be introduced by the telescope’s deformable secondary mirrors driven on the basis of the average wavefront errors computed from the respective guide star constellation. Measured atmospheric turbulence profiles from the site lead us to expect that by compensating the ground-layer turbulence, ARGOS will deliver median image quality of about 0.2 arc sec in the near infrared bands. This will be exploited by a pair of multi-object near-IR spectrographs, LUCI1 and LUCI2, each with 4 arc minute field already operating on the telescope. In future, ARGOS will also feed two interferometric imaging instruments, the LBT Interferometer operating in the thermal infrared, and LINC-NIRVANA, operating at visible and near infrared wavelengths. Together, these instruments will offer very broad spectral coverage at the diffraction limit of the LBT’s combined aperture, 23 m in size.

  17. Detector control and data acquisition for the wide field infrared survey telescope (WFIRST) with a custom ASIC

    NASA Astrophysics Data System (ADS)

    Smith, Brian; Loose, Markus; Alkire, Greg; Joshi, Atul; Kelly, Daniel; Siskind, Eric; Rossetti, Dino; Mah, Jonathan; Cheng, Edward; Miko, Laddawan; Luppino, Gerard; Culver, Harry; Wollack, Edward; Content, David

    2016-07-01

    The Wide-Field Infrared Survey Telescope (WFIRST) will have the largest near-IR focal plane ever flown by NASA, a total of 18 4K x 4K devices. The project has adopted a system-level approach to detector control and data acquisition where 1) control and processing intelligence is pushed into components closer to the detector to maximize signal integrity, 2) functions are performed at the highest allowable temperatures, and 3) the electronics are designed to ensure that the intrinsic detector noise is the limiting factor for system performance. For WFIRST, the detector arrays operate at 90 to 100 K, the detector control and data acquisition functions are performed by a custom ASIC at 150 to 180 K, and the main data processing electronics are at the ambient temperature of the spacecraft, notionally 300 K. The new ASIC is the main interface between the cryogenic detectors and the warm instrument electronics. Its single-chip design provides basic clocking for most types of hybrid detectors with CMOS ROICs. It includes a flexible but simple-to-program sequencer, with the option of microprocessor control for more elaborate readout schemes that may be data-dependent. All analog biases, digital clocks, and analog-to-digital conversion functions are incorporated and are connected to the nearby detectors with a short cable that can provide thermal isolation. The interface to the warm electronics is simple and robust through multiple LVDS channels. It also includes features that support parallel operation of multiple ASICs to control detectors that may have more capability or requirements than can be supported by a single chip.

  18. Brown dwarf photospheres are patchy: A Hubble space telescope near-infrared spectroscopic survey finds frequent low-level variability

    SciTech Connect

    Buenzli, Esther; Apai, Dániel; Radigan, Jacqueline; Reid, I. Neill; Flateau, Davin

    2014-02-20

    Condensate clouds strongly impact the spectra of brown dwarfs and exoplanets. Recent discoveries of variable L/T transition dwarfs argued for patchy clouds in at least some ultracool atmospheres. This study aims to measure the frequency and level of spectral variability in brown dwarfs and to search for correlations with spectral type. We used Hubble Space Telescope/Wide Field Camera 3 to obtain spectroscopic time series for 22 brown dwarfs of spectral types ranging from L5 to T6 at 1.1-1.7 μm for ≈40 minutes per object. Using Bayesian analysis, we find six brown dwarfs with confident (p > 95%) variability in the relative flux in at least one wavelength region at sub-percent precision, and five brown dwarfs with tentative (p > 68%) variability. We derive a minimum variability fraction f{sub min}=27{sub −7}{sup +11}% over all covered spectral types. The fraction of variables is equal within errors for mid-L, late-L, and mid-T spectral types; for early-T dwarfs we do not find any confident variable but the sample is too small to derive meaningful limits. For some objects, the variability occurs primarily in the flux peak in the J or H band, others are variable throughout the spectrum or only in specific absorption regions. Four sources may have broadband peak-to-peak amplitudes exceeding 1%. Our measurements are not sensitive to very long periods, inclinations near pole-on and rotationally symmetric heterogeneity. The detection statistics are consistent with most brown dwarf photospheres being patchy. While multiple-percent near-infrared variability may be rare and confined to the L/T transition, low-level heterogeneities are a frequent characteristic of brown dwarf atmospheres.

  19. Thirty Meter Telescope (TMT) Narrow Field Infrared Adaptive Optics System (NFIRAOS) real-time controller preliminary architecture

    NASA Astrophysics Data System (ADS)

    Kerley, Dan; Smith, Malcolm; Dunn, Jennifer; Herriot, Glen; Véran, Jean-Pierre; Boyer, Corinne; Ellerbroek, Brent; Gilles, Luc; Wang, Lianqi

    2016-08-01

    The Narrow Field Infrared Adaptive Optics System (NFIRAOS) is the first light Adaptive Optics (AO) system for the Thirty Meter Telescope (TMT). A critical component of NFIRAOS is the Real-Time Controller (RTC) subsystem which provides real-time wavefront correction by processing wavefront information to compute Deformable Mirror (DM) and Tip/Tilt Stage (TTS) commands. The National Research Council of Canada - Herzberg (NRC-H), in conjunction with TMT, has developed a preliminary design for the NFIRAOS RTC. The preliminary architecture for the RTC is comprised of several Linux-based servers. These servers are assigned various roles including: the High-Order Processing (HOP) servers, the Wavefront Corrector Controller (WCC) server, the Telemetry Engineering Display (TED) server, the Persistent Telemetry Storage (PTS) server, and additional testing and spare servers. There are up to six HOP servers that accept high-order wavefront pixels, and perform parallelized pixel processing and wavefront reconstruction to produce wavefront corrector error vectors. The WCC server performs low-order mode processing, and synchronizes and aggregates the high-order wavefront corrector error vectors from the HOP servers to generate wavefront corrector commands. The Telemetry Engineering Display (TED) server is the RTC interface to TMT and other subsystems. The TED server receives all external commands and dispatches them to the rest of the RTC servers and is responsible for aggregating several offloading and telemetry values that are reported to other subsystems within NFIRAOS and TMT. The TED server also provides the engineering GUIs and real-time displays. The Persistent Telemetry Storage (PTS) server contains fault tolerant data storage that receives and stores telemetry data, including data for Point-Spread Function Reconstruction (PSFR).

  20. Detector Control and Data Acquisition for the Wide-Field Infrared Survey Telescope (WFIRST) with a Custom ASIC

    NASA Technical Reports Server (NTRS)

    Smith, Brian S.; Loose, Markus; Alkire, Greg; Joshi, Atul; Kelly, Daniel; Siskind, Eric; Rossetti, Dino; Mah, Jonathan; Cheng, Edward; Miko, Laddawan; Luppino, Gerard; Culver, Harry; Wollack, Edward; Content, David

    2016-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) will have the largest near-IR focal plane ever flown by NASA, a total of 18 4K x 4K devices. The project has adopted a system-level approach to detector control and data acquisition where 1) control and processing intelligence is pushed into components closer to the detector to maximize signal integrity, 2) functions are performed at the highest allowable temperatures, and 3) the electronics are designed to ensure that the intrinsic detector noise is the limiting factor for system performance. For WFIRST, the detector arrays operate at 90 to 100 K, the detector control and data acquisition functions are performed by a custom ASIC at 150 to 180 K, and the main data processing electronics are at the ambient temperature of the spacecraft, notionally approx.300 K. The new ASIC is the main interface between the cryogenic detectors and the warm instrument electronics. Its single-chip design provides basic clocking for most types of hybrid detectors with CMOS ROICs. It includes a flexible but simple-to-program sequencer, with the option of microprocessor control for more elaborate readout schemes that may be data-dependent. All analog biases, digital clocks, and analog-to-digital conversion functions are incorporated and are connected to the nearby detectors with a short cable that can provide thermal isolation. The interface to the warm electronics is simple and robust through multiple LVDS channels. It also includes features that support parallel operation of multiple ASICs to control detectors that may have more capability or requirements than can be supported by a single chip.

  1. Multipulse interferometric frequency-resolved optical gating

    SciTech Connect

    Siders, C.W.; Siders, J.L.W.; Omenetto, F.G.; Taylor, A.J.

    1999-04-01

    The authors review multipulse interferometric frequency-resolved optical gating (MI-FROG) as a technique, uniquely suited for pump-probe coherent spectroscopy using amplified visible and near-infrared short-pulse systems and/or emissive targets, for time-resolving ultrafast phase shifts and intensity changes. Application of polarization-gate MI-FROG to the study of ultrafast ionization in gases is presented.

  2. Review of the absorption spectra of solid O2 and N2 as they relate to contamination of a cooled infrared telescope

    NASA Technical Reports Server (NTRS)

    Smith, S. M.

    1977-01-01

    During contamination studies for the liquid helium cooled shuttle infrared telescope facility, a literature search was conducted to determine the absorption spectra of the solid state of homonuclear molecules of O2 and N2, and ascertain what laboratory measurements of the solid have been made in the infrared. With the inclusion of one unpublished spectrum, the absorption spectrum of the solid oxygen molecule has been thoroughly studied from visible to millimeter wavelengths. Only two lines appear in the solid that do not also appear in the gas or liquid. A similar result is implied for the solid nitrogen molecule because it also is homonuclear. The observed infrared absorption lines result from lattice modes of the alpha phase of the solid, and disappear at the warmer temperatures of the beta, gamma, and liquid phases. They are not observed from polycrystalline forms of O2, while strong scattering is. Scattering, rather than absorption, is considered to be the principal natural contamination problem for cooled infrared telescopes in low earth orbit.

  3. Status report on the Large Binocular Telescope's ARGOS ground-layer AO system

    NASA Astrophysics Data System (ADS)

    Hart, M.; Rabien, S.; Busoni, L.; Barl, L.; Beckmann, U.; Bonaglia, M.; Boose, Y.; Borelli, J. L.; Bluemchen, T.; Carbonaro, L.; Connot, C.; Deysenroth, M.; Davies, R.; Durney, O.; Elberich, M.; Ertl, T.; Esposito, S.; Gaessler, W.; Gasho, V.; Gemperlein, H.; Hubbard, P.; Kanneganti, S.; Kulas, M.; Newman, K.; Noenickx, J.; Orban de Xivry, G.; Peter, D.; Quirrenbach, A.; Rademacher, M.; Schwab, C.; Storm, J.; Vaitheeswaran, V.; Weigelt, G.; Ziegleder, J.

    2011-10-01

    ARGOS, the laser-guided adaptive optics system for the Large Binocular Telescope (LBT), is now under construction at the telescope. By correcting atmospheric turbulence close to the telescope, the system is designed to deliver high resolution near infrared images over a field of 4 arc minute diameter. Each side of the LBT is being equipped with three Rayleigh laser guide stars derived from six 18 W pulsed green lasers and projected into two triangular constellations matching the size of the corrected field. The returning light is to be detected by wavefront sensors that are range gated within the seeing-limited depth of focus of the telescope. Wavefront correction will be introduced by the telescope's deformable secondary mirrors driven on the basis of the average wavefront errors computed from the respective guide star constellation. Measured atmospheric turbulence profiles from the site lead us to expect that by compensating the ground-layer turbulence, ARGOS will deliver median image quality of about 0.2 arc sec across the JHK bands. This will be exploited by a pair of multi-object near-IR spectrographs, LUCIFER1 and LUCIFER2, with 4 arc minute field already operating on the telescope. In future, ARGOS will also feed two interferometric imaging instruments, the LBT Interferometer operating in the thermal infrared, and LINC-NIRVANA, operating at visible and near infrared wavelengths. Together, these instruments will offer very broad spectral coverage at the diffraction limit of the LBT's combined aperture, 23 m in size.

  4. A near-infrared interferometric survey of debris-disc stars. III. First statistics based on 42 stars observed with CHARA/FLUOR

    NASA Astrophysics Data System (ADS)

    Absil, O.; Defrère, D.; Coudé du Foresto, V.; Di Folco, E.; Mérand, A.; Augereau, J.-C.; Ertel, S.; Hanot, C.; Kervella, P.; Mollier, B.; Scott, N.; Che, X.; Monnier, J. D.; Thureau, N.; Tuthill, P. G.; ten Brummelaar, T. A.; McAlister, H. A.; Sturmann, J.; Sturmann, L.; Turner, N.

    2013-07-01

    Context. Dust is expected to be ubiquitous in extrasolar planetary systems owing to the dynamical activity of minor bodies. Inner dust populations are, however, still poorly known because of the high contrast and small angular separation with respect to their host star, and yet, a proper characterisation of exozodiacal dust is mandatory for the design of future Earth-like planet imaging missions. Aims: We aim to determine the level of near-infrared exozodiacal dust emission around a sample of 42 nearby main sequence stars with spectral types ranging from A to K and to investigate its correlation with various stellar parameters and with the presence of cold dust belts. Methods: We use high-precision K-band visibilities obtained with the FLUOR interferometer on the shortest baseline of the CHARA array. The calibrated visibilities are compared with the expected visibility of the stellar photosphere to assess whether there is an additional, fully resolved circumstellar emission source. Results: Near-infrared circumstellar emission amounting to about 1% of the stellar flux is detected around 13 of our 42 target stars. Follow-up observations showed that one of them (eps Cep) is associated with a stellar companion, while another one was detected around what turned out to be a giant star (kap CrB). The remaining 11 excesses found around single main sequence stars are most probably associated with hot circumstellar dust, yielding an overall occurrence rate of 28+8-6 for our (biased) sample. We show that the occurrence rate of bright exozodiacal discs correlates with spectral type, K-band excesses being more frequent around A-type stars. It also correlates with the presence of detectable far-infrared excess emission in the case of solar-type stars. Conclusions: This study provides new insight into the phenomenon of bright exozodiacal discs, showing that hot dust populations are probably linked to outer dust reservoirs in the case of solar-type stars. For A-type stars, no

  5. Progress with the Prime Focus Spectrograph for the Subaru Telescope: a massively multiplexed optical and near-infrared fiber spectrograph

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Tamura, Naoyuki; Karoji, Hiroshi; Shimono, Atsushi; Takato, Naruhisa; Kimura, Masahiko; Ohyama, Youichi; Ueda, Akitoshi; Aghazarian, Hrand; de Arruda, Marcio V.; Barkhouser, Robert H.; Bennett, Charles L.; Bickerton, Steve; Bozier, Alexandre; Braun, David F.; Bui, Khanh; Capocasale, Christopher M.; Carr, Michael A.; Castilho, Bruno; Chang, Yin-Chang; Chen, Hsin-Yo; Chou, Richard C. Y.; Dawson, Olivia R.; Dekany, Richard G.; Ek, Eric M.; Ellis, Richard S.; English, Robin J.; Ferrand, Didier; Ferreira, Décio; Fisher, Charles D.; Golebiowski, Mirek; Gunn, James E.; Hart, Murdock; Heckman, Timothy M.; Ho, Paul T. P.; Hope, Stephen; Hovland, Larry E.; Hsu, Shu-Fu; Hu, Yen-Sang; Huang, Pin Jie; Jaquet, Marc; Karr, Jennifer E.; Kempenaar, Jason G.; King, Matthew E.; Le Fèvre, Olivier; Le Mignant, David; Ling, Hung-Hsu; Loomis, Craig; Lupton, Robert H.; Madec, Fabrice; Mao, Peter; Marrara, Lucas S.; Ménard, Brice; Morantz, Chaz; Murayama, Hitoshi; Murray, Graham J.; de Oliveira, Antonio Cesar; de Oliveira, Claudia M.; de Oliveira, Ligia S.; Orndorff, Joe D.; de Paiva Vilaça, Rodrigo; Partos, Eamon J.; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J.; Riddle, Reed; Santos, Leandro; dos Santos, Jesulino B.; Schwochert, Mark A.; Seiffert, Michael D.; Smee, Stephen A.; Smith, Roger M.; Steinkraus, Ronald E.; Sodré, Laerte; Spergel, David N.; Surace, Christian; Tresse, Laurence; Vidal, Clément; Vives, Sebastien; Wang, Shiang-Yu; Wen, Chih-Yi; Wu, Amy C.; Wyse, Rosie; Yan, Chi-Hung

    2014-07-01

    The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber spectrograph with 2394 science fibers, which are distributed in 1.3 degree diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide wavelength coverage from 0.38 μm to 1.26 μm, with the resolving power of 3000, strengthens its ability to target three main survey programs: cosmology, Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with resolving power of 5000 for 0.71 μm to 0.89 μm also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts (SuMIRe) project, while Hyper Suprime-Cam (HSC) works on the imaging part. HSC's excellent image qualities have proven the high quality of the Wide Field Corrector (WFC), which PFS shares with HSC. The PFS collaboration has succeeded in the project Preliminary Design Review and is now in a phase of subsystem Critical Design Reviews and construction. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated microlens is glued to each fiber tip. The microlenses are molded glass, providing uniform lens dimensions and a variety of refractive-index selection. After successful production of mechanical and optical samples, mass production is now complete. Following careful investigations including Focal Ratio Degradation (FRD) measurements, a higher transmission fiber is selected for the longest part of cable system, while one with a better FRD performance is selected for the fiber-positioner and fiber-slit components, given the more frequent fiber movements and tightly curved structure. Each Fiber positioner consists of two stages of piezo-electric rotary motors. Its engineering model has been produced and tested. After evaluating the statistics of positioning accuracies, collision avoidance software, and interferences (if any) within/between electronics boards, mass production will commence. Fiber

  6. INFRARED SPECTRAL ENERGY DISTRIBUTIONS OF SEYFERT GALAXIES: SPITZER SPACE TELESCOPE OBSERVATIONS OF THE 12 {mu}m SAMPLE OF ACTIVE GALAXIES

    SciTech Connect

    Gallimore, J. F.; Yzaguirre, A.; Jakoboski, J.; Stevenosky, M. J.; Axon, D. J.; O'Dea, C. P.; Robinson, A.; Baum, S. A.; Buchanan, C. L.; Elitzur, M.; Elvis, M.

    2010-03-01

    The mid-infrared spectral energy distributions (SEDs) of 83 active galaxies, mostly Seyfert galaxies, selected from the extended 12 {mu}m sample are presented. The data were collected using all three instruments, Infrared Array Camera (IRAC), Infrared Spectrograph (IRS), and Multiband Imaging Photometer for Spitzer (MIPS), aboard the Spitzer Space Telescope. The IRS data were obtained in spectral mapping mode, and the photometric data from IRAC and IRS were extracted from matched, 20'' diameter circular apertures. The MIPS data were obtained in SED mode, providing very low-resolution spectroscopy (R {approx} 20) between {approx}55 and 90 {mu}m in a larger, 20'' x 30'' synthetic aperture. We further present the data from a spectral decomposition of the SEDs, including equivalent widths and fluxes of key emission lines; silicate 10 {mu}m and 18 {mu}m emission and absorption strengths; IRAC magnitudes; and mid-far-infrared spectral indices. Finally, we examine the SEDs averaged within optical classifications of activity. We find that the infrared SEDs of Seyfert 1s and Seyfert 2s with hidden broad line regions (HBLRs, as revealed by spectropolarimetry or other technique) are qualitatively similar, except that Seyfert 1s show silicate emission and HBLR Seyfert 2s show silicate absorption. The infrared SEDs of other classes within the 12 {mu}m sample, including Seyfert 1.8-1.9, non-HBLR Seyfert 2 (not yet shown to hide a type 1 nucleus), LINER, and H II galaxies, appear to be dominated by star formation, as evidenced by blue IRAC colors, strong polycyclic aromatic hydrocarbon emission, and strong far-infrared continuum emission, measured relative to mid-infrared continuum emission.

  7. Prime Focus Spectrograph: A very wide-field, massively multiplexed, optical & near-infrared spectrograph for Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Tamura, Naoyuki

    This short article is about Prime Focus Spectrograph (PFS), a very wide-field, massively-multiplexed, and optical & near-infrared (NIR) spectrograph as a next generation facility instrument on Subaru Telescope. More details and updates are available on the PFS official website (http://pfs.ipmu.jp), blog (http://pfs.ipmu.jp/blog/), and references therein. The project, instrument, & timeline PFS will position 2400 fibers to science targets or blank sky in the 1.3 degree field on the Subaru prime focus. These fibers will be quickly (~60sec) reconfigurable and feed the photons during exposures to the Spectrograph System (SpS). SpS consists of 4 modules each of which accommodate ~600 fibers and deliver spectral images ranging from 380nm to 1260nm simultaneously at one exposure via the 3 arms of blue, red, and NIR cameras. The instrument development has been undertaken by the international collaboration at the initiative of Kavli IPMU. The project is now going into the construction phase aiming at system integration and on-sky engineering observations in 2017-2018, and science operation in 2019. The survey design has also been under development envisioning a survey spanning ~300 nights over ~5 years in the framework of Subaru Strategic Program (SSP). The key science areas are: Cosmology, galaxy/AGN evolution, and Galactic Archaeology (GA) (Takada et al. 2014). The cosmology program will be to constrain the nature of dark energy via a survey of emission line galaxies over a comoving volume of 10 Gpc3 at z=0.8-2.4. In the galaxy/AGN program, the wide wavelength coverage of PFS as well as the large field of view will be exploited to characterize the galaxy populations and its clustering properties over a wide redshift range. A survey of color-selected galaxies/AGN at z = 1-2 will be conducted over 20 square degrees yielding a fair sample of galaxies with stellar masses down to ~1010 M ⊙. In the GA program, radial velocities and chemical abundances of stars in the Milky

  8. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    SciTech Connect

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E.; Ryan, R. E.; Koekemoer, A. M.; Schneider, G.; Fan, X.; Hathi, N. P.; Keel, W. C.; Roettgering, H.; Schneider, D. P.; Strauss, M. A.; Yan, H. J.

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  9. Coherence versus interferometric resolution

    SciTech Connect

    Luis, Alfredo

    2010-06-15

    We examine the relation between second-order coherence and resolution in the interferometric detection of phase shifts. While for classical thermal light resolution and second-order coherence are synonymous, we show that for quantum light beams reaching optimum precision second-order coherence and resolution become antithetical.

  10. A near-infrared interferometric survey of debris-disk stars. IV. An unbiased sample of 92 southern stars observed in H band with VLTI/PIONIER

    NASA Astrophysics Data System (ADS)

    Ertel, S.; Absil, O.; Defrère, D.; Le Bouquin, J.-B.; Augereau, J.-C.; Marion, L.; Blind, N.; Bonsor, A.; Bryden, G.; Lebreton, J.; Milli, J.

    2014-10-01

    Context. Detecting and characterizing circumstellar dust is a way to study the architecture and evolution of planetary systems. Cold dust in debris disks only traces the outer regions. Warm and hot exozodiacal dust needs to be studied in order to trace regions close to the habitable zone. Aims: We aim to determine the prevalence and to constrain the properties of hot exozodiacal dust around nearby main-sequence stars. Methods: We searched a magnitude-limited (H ≤ 5) sample of 92 stars for bright exozodiacal dust using our VLTI visitor instrument PIONIER in the H band. We derived statistics of the detection rate with respect to parameters, such as the stellar spectral type and age or the presence of a debris disk in the outer regions of the systems. We derived more robust statistics by combining our sample with the results from our CHARA/FLUOR survey in the K band. In addition, our spectrally dispersed data allowed us to put constraints on the emission mechanism and the dust properties in the detected systems. Results: We find an overall detection rate of bright exozodiacal dust in the H band of 11% (9 out of 85 targets) and three tentative detections. The detection rate decreases from early type to late type stars and increases with the age of the host star. We do not confirm the tentative correlation between the presence of cold and hot dust found in our earlier analysis of the FLUOR sample alone. Our spectrally dispersed data suggest that either the dust is extremely hot or the emission is dominated by the scattered light in most cases. The implications of our results for the target selection of future terrestrial planet-finding missions using direct imaging are discussed. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program IDs 089.C-0365 and 090.C-0526.Appendix A and Table 1 are available in electronic form at http://www.aanda.org

  11. 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)

  12. The Mechanical Design of a Kinematic Mount for the Mid Infrared Instrument Focal Plane Module on the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Thelen, Michael P.; Moore, Donald M.

    2009-01-01

    The detector assembly for the Mid Infrared Instrument (MIRI) of the James Webb Space Telescope (JWST) is mechanically supported in the Focal Plane Module (FPM) Assembly with an efficient hexapod design. The kinematic mount design allows for precision adjustment of the detector boresight to assembly alignment fiducials and maintains optical alignment requirements during flight conditions of launch and cryogenic operations below 7 Kelvin. This kinematic mounting technique is able to be implemented in a variety of optical-mechanical designs and is capable of micron level adjustment control and stability over wide dynamic and temperature ranges.

  13. Far-Infrared Photometry with an 0.4-Meter Liquid Helium Cooled Balloon-Borne Telescope. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Jacobson, M. R.

    1977-01-01

    A 0.4-meter aperture, liquid helium cooled multichannel far-infrared balloon-borne telescope was constructed to survey the galactic plane. Nine new sources, above a 3-sigma confidence level of 1300 Jy, were identified. Although two-thirds of the scanned area was more than 10 degrees from the galactic plane, no sources were detected in that region; all nine fell within 10 degrees and eight of those within 4 degrees of the galactic equator. Correlations with visible, compact H lines associated with radio continuum and with sources displaying spectra steeply rising between 11 and 20 microns were noted, while stellar objects were not detected.

  14. Longer-baseline telescopes using quantum repeaters.

    PubMed

    Gottesman, Daniel; Jennewein, Thomas; Croke, Sarah

    2012-08-17

    We present an approach to building interferometric telescopes using ideas of quantum information. Current optical interferometers have limited baseline lengths, and thus limited resolution, because of noise and loss of signal due to the transmission of photons between the telescopes. The technology of quantum repeaters has the potential to eliminate this limit, allowing in principle interferometers with arbitrarily long baselines.

  15. FORCAST Camera Installed on SOFIA Telescope

    NASA Video Gallery

    Cornell University's Faint Object Infrared Camera for the SOFIA Telescope, or FORCAST, being installed on the Stratospheric Observatory for Infrared Astronomy's 2.5-meter telescope in preparation f...

  16. 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.

  17. Precision Interferometric Dilatometer

    DTIC Science & Technology

    2013-05-23

    reference mirrors on a ULE glass or Zerodur block in a thermally insulated - part of the system. Since the BIP, (or B2P2) paths are in air, mounting...into the vacuum chamber. The reference mirror support (e.g., Zerodur ) is shielded from temperature excursion, and a conservative error is ALu - aL... Mirror (1000 V B 15 pm motion)s............s.. 24 10. Interferometric Counter Output vs. Voltage Applied to PZT-Driven Mirror (fine scale

  18. Interferometric Remapped Array Nulling

    NASA Astrophysics Data System (ADS)

    Abe, L.; Aristidi, E.; Vakili, F.; Domiciano, A.

    We present an interferometric beam recombination technique which allows achromatic and direct true imaging of targets at very high angular resolution. This technique intrinsically overcomes the main problems of Labeyrie's hypertelescope design, and can be used in a nulling configuration. It is thus particularly well suited for high contrast imaging in the context of exo-planet search and characterization especially for future space-borne arrays. We present the concept on a formal basis, and discuss its instrumental implementation.

  19. CEPHEID PERIOD-LUMINOSITY RELATIONS IN THE NEAR-INFRARED AND THE DISTANCE TO M31 FROM THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    SciTech Connect

    Riess, Adam G.; Fliri, Juergen; Valls-Gabaud, David E-mail: jurgen.fliri@obspm.fr

    2012-02-01

    We present measurements of 68 classical Cepheids, most detected from the Canada-France-Hawaii Telescope POMME Survey, with periods from 10 to 78 days observed in the near-infrared by the Panchromatic Hubble Andromeda Treasury Program using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). The combination of HST's resolution and the use of near-infrared measurements provide a dramatic reduction in the dispersion of the period-luminosity relation over the present optical, ground-based data. Even using random phase magnitudes we measure a dispersion of just 0.17 mag, implying a dispersion of just 0.12 mag for mean magnitudes. The error in the mean for this relation is 1% in distance. Combined with similar observations of Cepheids in other hosts and independent distance determinations, we measure a distance to M31 of {mu}{sub 0} = 24.38 {+-} 0.06(statistical) {+-} 0.03(systematic), 752 {+-} 27 kpc, in good agreement with past measurements though with a better, 3% precision here. The result is also in good agreement with independent distance determinations from two detached eclipsing binaries allowing for an independent calibration of the Cepheid luminosities and a determination of the Hubble constant.

  20. The close circumstellar environment of Betelgeuse. IV. VLTI/PIONIER interferometric monitoring of the photosphere

    NASA Astrophysics Data System (ADS)

    Montargès, M.; Kervella, P.; Perrin, G.; Chiavassa, A.; Le Bouquin, J.-B.; Aurière, M.; López Ariste, A.; Mathias, P.; Ridgway, S. T.; Lacour, S.; Haubois, X.; Berger, J.-P.

    2016-04-01

    Context. The mass-loss mechanism of cool massive evolved stars is poorly understood. The proximity of Betelgeuse makes it an appealing target to study its atmosphere, map the shape of its envelope, and follow the structure of its wind from the photosphere out to the interstellar medium. Aims: A link is suspected between the powerful convective motions in Betelgeuse and its mass loss. We aim to constrain the spatial structure and temporal evolution of the convective pattern on the photosphere and to search for evidence of this link. Methods: We report new interferometric observations in the infrared H-band using the VLTI/PIONIER instrument. We monitored the photosphere of Betelgeuse between 2012 January and 2014 November to look for evolutions that may trigger the outflow. Results: Our interferometric observations at low spatial frequencies are compatible with the presence of a hot spot on the photosphere that has a characteristic width of one stellar radius. It appears to be superposed on the smaller scale convective pattern. In the higher spatial frequency domain, we observe a significant difference between the observations and the predictions of 3D hydrodynamical simulations. Conclusions: We bring new evidence for the presence of a convective pattern in the photosphere of red supergiants. The inferred hot spot is probably the top of a giant convection cell although an asymmetric extension of the star cannot be excluded by these interferometric observations alone. The properties of the observed surface features show a stronger contrast and inhomogeneity as predicted by 3D radiative hydrodynamical simulations. We propose that the large observed feature is modifying the signature of the convective pattern at the surface of the star in a way that simulations cannot reproduce. Based on observations made with ESO telescopes at Paranal Observatory, under ESO programs 288.D-5035(A), 090.D-0548(A), 092.D-0366(A), 092.D-0366(B) and 094.D-0869 (A).

  1. Design Tradeoffs for a High Spectral Resolution Mid-Infrared Echelle Spectrograph on the Thirty-Meter Telescope

    DTIC Science & Technology

    2006-01-01

    characterizing extrasolar planetary systems with the Kepler mission, Space Interferometry Mission, Gemini Precision Radial Velocity Spectrometer, Gemini... Planet Imager, Atacama Large Millimeter Array, and the James Webb Space Telescope...that will allow high-angular resolution imaging to be accomplished. MIRES on the TMT will be a powerful tool for probing planet formation

  2. Technology Development for the Advanced Technology Large Aperture Space Telescope (ATLAST) as a Candidate Large UV-Optical-Infrared (LUVOIR) Surveyor

    NASA Technical Reports Server (NTRS)

    Bolcar, Matthew R.; Balasubramanian, Kunjithapatha; Clampin, Mark; Crooke, Julie; Feinberg, Lee; Postman, Marc; Quijada, Manuel; Rauscher, Bernard; Redding, David; Rioux, Norman; Shaklan, Stuart; Stahl, H. Philip; Stahle, Carl; Thronson, Harley

    2015-01-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) team has identified five key technologies to enable candidate architectures for the future large-aperture ultraviolet/optical/infrared (LUVOIR) space observatory envisioned by the NASA Astrophysics 30-year roadmap, Enduring Quests, Daring Visions. The science goals of ATLAST address a broad range of astrophysical questions from early galaxy and star formation to the processes that contributed to the formation of life on Earth, combining general astrophysics with direct-imaging and spectroscopy of habitable exoplanets. The key technologies are: internal coronagraphs, starshades (or external occulters), ultra-stable large-aperture telescopes, detectors, and mirror coatings. Selected technology performance goals include: 1x10?10 raw contrast at an inner working angle of 35 milli-arcseconds, wavefront error stability on the order of 10 pm RMS per wavefront control step, autonomous on-board sensing & control, and zero-read-noise single-photon detectors spanning the exoplanet science bandpass between 400 nm and 1.8 µm. Development of these technologies will provide significant advances over current and planned observatories in terms of sensitivity, angular resolution, stability, and high-contrast imaging. The science goals of ATLAST are presented and flowed down to top-level telescope and instrument performance requirements in the context of a reference architecture: a 10-meter-class, segmented aperture telescope operating at room temperature (290 K) at the sun-Earth Lagrange-2 point. For each technology area, we define best estimates of required capabilities, current state-of-the-art performance, and current Technology Readiness Level (TRL) - thus identifying the current technology gap. We report on current, planned, or recommended efforts to develop each technology to TRL 5.

  3. Technology development for the Advanced Technology Large Aperture Space Telescope (ATLAST) as a candidate large UV-Optical-Infrared (LUVOIR) surveyor

    NASA Astrophysics Data System (ADS)

    Bolcar, Matthew R.; Balasubramanian, Kunjithapatham; Clampin, Mark; Crooke, Julie; Feinberg, Lee; Postman, Marc; Quijada, Manuel; Rauscher, Bernard; Redding, David; Rioux, Norman; Shaklan, Stuart; Stahl, H. Philip; Stahle, Carl; Thronson, Harley

    2015-09-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) team has identified five key technologies to enable candidate architectures for the future large-aperture ultraviolet/optical/infrared (LUVOIR) space observatory envisioned by the NASA Astrophysics 30-year roadmap, Enduring Quests, Daring Visions. The science goals of ATLAST address a broad range of astrophysical questions from early galaxy and star formation to the processes that contributed to the formation of life on Earth, combining general astrophysics with direct-imaging and spectroscopy of habitable exoplanets. The key technologies are: internal coronagraphs, starshades (or external occulters), ultra-stable large-aperture telescopes, detectors, and mirror coatings. Selected technology performance goals include: 1x10-10 raw contrast at an inner working angle of 35 milli-arcseconds, wavefront error stability on the order of 10 pm RMS per wavefront control step, autonomous on-board sensing and control, and zero-read-noise single-photon detectors spanning the exoplanet science bandpass between 400 nm and 1.8 μm. Development of these technologies will provide significant advances over current and planned observatories in terms of sensitivity, angular resolution, stability, and high-contrast imaging. The science goals of ATLAST are presented and flowed down to top-level telescope and instrument performance requirements in the context of a reference architecture: a 10-meter-class, segmented aperture telescope operating at room temperature (~290 K) at the sun-Earth Lagrange-2 point. For each technology area, we define best estimates of required capabilities, current state-of-the-art performance, and current Technology Readiness Level (TRL) - thus identifying the current technology gap. We report on current, planned, or recommended efforts to develop each technology to TRL 5.

  4. 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...

  5. Deep 610-MHz Giant Metrewave Radio Telescope observations of the Spitzer extragalactic First Look Survey field - III. The radio properties of infrared-faint radio sources

    NASA Astrophysics Data System (ADS)

    Garn, Timothy; Alexander, Paul

    2008-12-01

    Infrared-faint radio sources (IFRSs) are a class of source which are bright at radio frequencies, but do not appear in deep infrared images. We report the detection of 14 IFRSs within the Spitzer extragalactic First Look Survey field, eight of which are detected near to the limiting magnitude of a deep R-band image of the region, at R ~ 24.5. Sensitive Spitzer Space Telescope images are stacked in order to place upper limits on their mid-infrared flux densities, and using recent 610-MHz and 1.4-GHz observations we find that they have spectral indices which vary between α = 0.05 and 1.38, where we define α such that Sν = S0ν-α, and should not be thought of as a single source population. We place constraints on the luminosity and linear size of these sources, and through comparison with well-studied local objects in the Revised Revised Third Cambridge catalogue demonstrate that they can be modelled as being compact (<20 kpc) Fanaroff-Riley type II (FRII) radio galaxies located at high redshift (z ~ 4).

  6. Nonlinear interferometric vibrational imaging.

    PubMed

    Marks, Daniel L; Boppart, Stephen A

    2004-03-26

    Coherent anti-Stokes Raman scattering (CARS) processes are "coherent," but the phase of the anti-Stokes radiation is lost by most incoherent spectroscopic CARS measurements. We propose a Raman microscopy imaging method called nonlinear interferometric vibrational imaging, which measures Raman spectra by obtaining the temporal anti-Stokes signal through nonlinear interferometry. With a more complete knowledge of the anti-Stokes signal, we show through simulations that a high-resolution Raman spectrum can be obtained of a molecule in a single pulse using broad band radiation. This could be useful for identifying the three-dimensional spatial distribution of molecular species in tissue.

  7. Moving toward queue operations at the Large Binocular Telescope Observatory

    NASA Astrophysics Data System (ADS)

    Edwards, Michelle L.; Summers, Doug; Astier, Joseph; Suarez Sola, Igor; Veillet, Christian; Power, Jennifer; Cardwell, Andrew; Walsh, Shane

    2016-07-01

    The Large Binocular Telescope Observatory (LBTO), a joint scientific venture between the Instituto Nazionale di Astrofisica (INAF), LBT Beteiligungsgesellschaft (LBTB), University of Arizona, Ohio State University (OSU), and the Research Corporation, is one of the newest additions to the world's collection of large optical/infrared ground-based telescopes. With its unique, twin 8.4m mirror design providing a 22.8 meter interferometric baseline and the collecting area of an 11.8m telescope, LBT has a window of opportunity to exploit its singular status as the "first" of the next generation of Extremely Large Telescopes (ELTs). Prompted by urgency to maximize scientific output during this favorable interval, LBTO recently re-evaluated its operations model and developed a new strategy that augments classical observing with queue. Aided by trained observatory staff, queue mode will allow for flexible, multi-instrument observing responsive to site conditions. Our plan is to implement a staged rollout that will provide many of the benefits of queue observing sooner rather than later - with more bells and whistles coming in future stages. In this paper, we outline LBTO's new scientific model, focusing specifically on our "lean" resourcing and development, reuse and adaptation of existing software, challenges presented from our one-of-a-kind binocular operations, and lessons learned. We also outline further stages of development and our ultimate goals for queue.

  8. Interferometric Fiber Optic Sensors

    PubMed Central

    Lee, Byeong Ha; Kim, Young Ho; Park, Kwan Seob; Eom, Joo Beom; Kim, Myoung Jin; Rho, Byung Sup; Choi, Hae Young

    2012-01-01

    Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG) is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair. PMID:22736961

  9. Interferometric fiber optic sensors.

    PubMed

    Lee, Byeong Ha; Kim, Young Ho; Park, Kwan Seob; Eom, Joo Beom; Kim, Myoung Jin; Rho, Byung Sup; Choi, Hae Young

    2012-01-01

    Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG) is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  10. HUBBLE SPACE TELESCOPE Near-infrared and Optical Imaging of Faint Radio Sources in the Distant Cluster CL 0939+4713

    NASA Astrophysics Data System (ADS)

    Smail, Ian; Morrison, G.; Gray, M. E.; Owen, F. N.; Ivison, R. J.; Kneib, J.-P.; Ellis, R. S.

    1999-11-01

    We present deep Hubble Space Telescope Near-Infrared Camera and Multiobject Spectrograph (NICMOS) and Wide Field and Planetary Camera 2 (WFPC2) optical imaging of a small region in the core of the distant rich cluster Cl 0939+4713 (z=0.41). We compare the optical and near-infrared morphologies of cluster members and find apparent small-scale optical structures within the galaxies that are absent in the near-infrared. We conclude that strong dust obscuration is a common feature in the late-type galaxies in distant clusters. We then concentrate on a sample of 10 faint radio galaxies lying within our NICMOS field and selected from a very deep 1.4 GHz VLA map of the cluster with a 1 σ flux limit of 9 μJy. Using published data we focus on the spectral properties of the eight radio-selected cluster members and show that these comprise a large fraction of the poststarburst population in the cluster. The simplest interpretation of the radio emission from these galaxies is that they are currently forming massive stars, contradicting their classification as poststarburst systems based on the optical spectra. We suggest that this star formation is hidden from view in the optical by the same obscuring dust that is apparent in our comparison on the optical and near-infrared morphologies of these galaxies. We caution that even in the rest-frame optical the effects of dust cannot be ignored when comparing samples of distant galaxies to low-redshift systems, particularly if dust is as prevalent in distant galaxies as appears to be the case in our study.

  11. Laser interferometric high-precision geometry (angle and length) monitor for JASMINE

    NASA Astrophysics Data System (ADS)

    Niwa, Y.; Arai, K.; Ueda, A.; Sakagami, M.; Gouda, N.; Kobayashi, Y.; Yamada, Y.; Yano, T.

    2008-07-01

    The telescope geometry of JASMINE should be stabilized and monitored with the accuracy of about 10 to 100 pm or 10 to 100 prad of rms over about 10 hours. For this purpose, a high-precision interferometric laser metrology system is employed. Useful techniques for measuring displacements on extremely small scales are the wave-front sensing method and the heterodyne interferometrical method. Experiments for verification of measurement principles are well advanced.

  12. Nanohertz gravitational wave searches with interferometric pulsar timing experiments.

    PubMed

    Tinto, Massimo

    2011-05-13

    We estimate the sensitivity to nano-Hertz gravitational waves of pulsar timing experiments in which two highly stable millisecond pulsars are tracked simultaneously with two neighboring radio telescopes that are referenced to the same timekeeping subsystem (i.e., "the clock"). By taking the difference of the two time-of-arrival residual data streams we can exactly cancel the clock noise in the combined data set, thereby enhancing the sensitivity to gravitational waves. We estimate that, in the band (10(-9)-10(-8))  Hz, this "interferometric" pulsar timing technique can potentially improve the sensitivity to gravitational radiation by almost 2 orders of magnitude over that of single-telescopes. Interferometric pulsar timing experiments could be performed with neighboring pairs of antennas of the NASA's Deep Space Network and the forthcoming large arraying projects.

  13. Near-infrared Emission Spectrum of WASP-103b Using Hubble Space Telescope/Wide Field Camera 3

    NASA Astrophysics Data System (ADS)

    Cartier, Kimberly M. S.; Beatty, Thomas G.; Zhao, Ming; Line, Michael; Ngo, Henry; Mawet, Dimitri; Stassun, Keivan G.; Wright, Jason T.; Kreidberg, Laura; Fortney, Jonathan; Knutson, Heather

    2017-01-01

    We present here our observations and analysis of the dayside emission spectrum of the hot Jupiter WASP-103b. We observed WASP-103b during secondary eclipse using two visits of the Hubble Space Telescope with the G141 grism on Wide Field Camera 3 in spatial scan mode. We generated secondary eclipse light curves of the planet in both blended white-light and spectrally binned wavechannels from 1.1 {to} 1.7 μ {{m}} and corrected the light curves for flux contamination from a nearby companion star. We modeled the detector systematics and secondary eclipse spectrum using Gaussian process regression and found that the near-IR emission spectrum of WASP-103b is featureless across the observed near-IR region to down to a sensitivity of 175 ppm, and shows a shallow slope toward the red. The atmosphere has a single brightness temperature of {T}{{B}}=2890 K across this wavelength range. This region of the spectrum is indistinguishable from isothermal, but may not manifest from a physically isothermal system, i.e., pseudo-isothermal. A solar-metallicity profile with a thermal inversion layer at 10‑2 bar fits the spectrum of WASP-103b with high confidence, as do an isothermal profile with solar metallicity and a monotonically decreasing atmosphere with C/O > 1. The data rule out a monotonically decreasing atmospheric profile with solar composition, and we rule out a low-metallicity decreasing profile as unphysical for this system. The pseudo-isothermal profile could be explained by a thermal inversion layer just above the layer probed by our observations, or by clouds or haze in the upper atmosphere. Transmission spectra at optical wavelengths would allow us to better distinguish between potential atmospheric models. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  14. Development status of the mid-infrared two-field camera and spectrograph MIMIZUKU for the TAO 6.5-m Telescope

    NASA Astrophysics Data System (ADS)

    Kamizuka, Takafumi; Miyata, Takashi; Sako, Shigeyuki; Ohsawa, Ryou; Okada, Kazushi; Uchiyama, Masahito S.; Mori, Kiyoshi; Yamaguchi, Jumpei; Asano, Kentaro; Uchiyama, Mizuho; Sakon, Itsuki; Onaka, Takashi; Kataza, Hirokazu; Hasegawa, Sunao; Usui, Fumihiko; Takato, Naruhisa; Aoki, Tsutomu; Doi, Mamoru; Kato, Natsuko M.; Kitagawa, Yutaro; Kobayakawa, Yutaka; Kohno, Kotaro; Konishi, Masahiro; Minezaki, Takeo; Morokuma, Tomoki; Motohara, Kentaro; Ohashi, Hirofumi; Soyano, Takao; Takahashi, Hidenori; Tamura, Yoichi; Tanabé, Toshihiko; Tanaka, Masuo; Tarusawa, Ken'ichi; Terao, Yasunori; Yoshii, Yuzuru

    2016-08-01

    MIMIZUKU is the first-generation mid-infrared instrument for the university of Tokyo Atacama Observatory (TAO) 6.5-m telescope. MIMIZUKU provides imaging and spectroscopic monitoring capabilities in a wide wavelength range from 2 to 38 μm, including unique bands like 2.7-μm and 30-μm band. Recently, we decided to add spectroscopic functions, KL-band mode (λ= 2.1-4.0 μm R =λ/Δλ 210) and 2.7-μm band mode ( λ= 2.4-2.95 μm R 620), and continuous spectroscopic coverage from 2.1 to 26 μm is realized by this update. Their optical designing is completed, and fabrications of optical elements are ongoing. As recent progress, we also report the completion of the cryogenic system and optics. The cryogenic system has been updated by changing materials and structures of thermal links, and the temperatures of the optical bench and detector mounting stages finally achieved required temperatures. Their stability against instrument attitude is also confirmed through an inclination test. As for the optics, its gold-plated mirrors have been recovered from galvanic corrosion by refabrication and reconstruction. Enough image quality and stability are confirmed by room-temperature tests. MIMIZUKU is intended to be completed in this autumn, and commissioning at the Subaru telescope and scientific operations on the TAO telescope are planned in 2017 and around 2019, respectively. In this paper, these development activities and future prospects of MIMIZUKU are reported.

  15. 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.

  16. First light observation of GIGMICS (germanium immersion grating mid-infrared cryogenic spectrograph) by Kanata 1.5-m Telescope at Higashi-Hiroshima Observatory

    NASA Astrophysics Data System (ADS)

    Hirahara, Yasuhiro; Aoki, Keishin; Ohta, Kanako; Shibata, Sho; Hirao, Tsuyoshi; Tatamitani, Yoshio; Ebizuka, Noboru; Kawabata, Koji S.; Yoshida, Michitoshi; Uemura, Makoto; Oosugi, Takashi; Kawaguchi, Kentaro; Fujimori, Ryuji; Ohiwa, Hiroki; Nagahiro, Hisayuki

    2012-09-01

    We have developed a germanium immersion grating mid-infrared cryogenic spectrograph (GIGMICS) designed for the Nasmyth focus stage of NAOJ Subaru 8.2-m telescope, which operates at N-band (8-13 μm) in wavelength (λ) with maximum resolving power R(≡λ/Δλ) ~ 50,000. A single crystal germanium echelle immersion grating (30 × 30 × 72 mm) for collimated beam size of 28 mmφ was fabricated by utilizing ultra precision micro-grinding method coupled with the ELID (ELectrolytic In-process Dressing) technique (Ohmori, H. 1992, Ebizuka et al. 2003, Tokoro et al. 2003). After the critical test for the application to the laboratory gas-phase IR high-resolution spectroscopy(Hirahara et al. 2010), we have conducted the "first light" astronomical observation of GIGMICS by the Kanata 1.5-m telescope at Higashi- Hiroshima Observatory from January to April, 2011. Toward many astronomical objects such as the Moon, Venus, Jupiter, circumstellar envelopes of late-type stars, proto-planetary nebulae, and interstellar molecular clouds in the vicinity of star-forming regions, we conducted spectroscopic observations in the N-band region.

  17. The Performance and Scientific Rationale for an Infrared Imaging Fourier Transform Spectrograph on a Large Space Telescope

    DTIC Science & Technology

    1998-06-22

    their youth. An exciting prospect is the study of extrasolar giant planets (EGPs) that have been ejected from young planetary systems. The unexpected...spectrometers developed at the Goddard Space Flight Center (GSFC) flew on board the Mariner 9 mission to Mars and were carried to the outer planets by the...giant gaseous planets (e.g., Jupiter; Hanel et al. 1979). The Composite Infrared Spectrom- eter (CIRS), currently traveling to Saturn on board the Cassini

  18. Differential interferometric measurement of mirror shape parameters

    NASA Astrophysics Data System (ADS)

    Robinson, Brian

    This project was inspired by the need for a remote method to accurately measure radius of curvature of mirrors tested under the NASA Advanced Mirror System Demonstrator program. Under this program, off axis parabolas (subscale candidates for James Webb Space Telescope optical elements) were tested under cryo-vac conditions. A remote, differential interferometric method is presented for measuring the shape parameters of general aspheric mirrors. The result of measurement is the assignment of best-fit values to a set of parameters that characterize the shape of the surface. If the mirror is nominally a conic of rotation, for example, the measurement yields the radius of curvature and conic constant. The method involves testing the optic in an interferometric center-of-curvature null configuration but can easily be extended to include conjugate null tests. During the measurement, known translational misalignments are introduced and the effects on the optical path length function are measured using a phase-shifting interferometer. Based on the nominal mirror shape, a model function is defined, up to a set of free shape parameters. The mirror shape parameters are regressed, based on the interferometric data, from this model. This differential measurement method works for on- and off-axis mirrors of all shapes and can be applied remotely as long as the mirror is mounted on an actuated stage. Hence, this measurement method would work well in a cryogenic testing situation. We have successfully applied the method to the case of an off-axis parabola with a nominal radius of curvature of 304.8 mm, a diameter of 76.17 mm, and a pupil offset of -89.40 mm.

  19. THE FIRST DETECTION OF GeV EMISSION FROM AN ULTRALUMINOUS INFRARED GALAXY: Arp 220 AS SEEN WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Peng, Fang-Kun; Wang, Xiang-Yu; Liu, Ruo-Yu; Tang, Qing-Wen; Wang, Jun-Feng

    2016-04-20

    Cosmic rays (CRs) in starburst galaxies produce high-energy gamma-rays by colliding with the dense interstellar medium. Arp 220 is the nearest ultraluminous infrared galaxy that has star formation at extreme levels, so it has long been predicted to emit high-energy gamma-rays. However, no evidence of gamma-ray emission was found despite intense search efforts. Here we report the discovery of high-energy gamma-ray emission above 200 MeV from Arp 220 at a confidence level of ∼6.3σ using 7.5 years of Fermi Large Area Telescope observations. The gamma-ray emission shows no significant variability over the observation period and it is consistent with the quasi-linear scaling relation between the gamma-ray luminosity and total infrared luminosity for star-forming galaxies, suggesting that these gamma-rays arise from CR interactions. As the high-density medium of Arp 220 makes it an ideal CR calorimeter, the gamma-ray luminosity can be used to measure the efficiency of powering CRs by supernova (SN) remnants given a known supernova rate in Arp 220. We find that this efficiency is about 4.2 ± 2.6% for CRs above 1 GeV.

  20. SPIRou: the near-infrared spectropolarimeter/high-precision velocimeter for the Canada-France-Hawaii telescope

    NASA Astrophysics Data System (ADS)

    Artigau, Étienne; Kouach, Driss; Donati, Jean-François; Doyon, René; Delfosse, Xavier; Baratchart, Sébastien; Lacombe, Marielle; Moutou, Claire; Rabou, Patrick; Parès, Laurent P.; Micheau, Yoan; Thibault, Simon; Reshetov, Vladimir A.; Dubois, Bruno; Hernandez, Olivier; Vallée, Philippe; Wang, Shiang-Yu; Dolon, François; Pepe, Francesco A.; Bouchy, François; Striebig, Nicolas; Hénault, François; Loop, David; Saddlemyer, Leslie; Barrick, Gregory; Vermeulen, Tom; Dupieux, Michel; Hébrard, Guillaume; Boisse, Isabelle; Martioli, Eder; Alencar, Silvia H. P.; do Nascimento, José-Diaz; Figueira, Pedro

    2014-07-01

    SPIRou is a near-IR echelle spectropolarimeter and high-precision velocimeter under construction as a next- generation instrument for the Canada-France-Hawaii-Telescope. It is designed to cover a very wide simultaneous near-IR spectral range (0.98-2.35 μm) at a resolving power of 73.5K, providing unpolarized and polarized spectra of low-mass stars at a radial velocity (RV) precision of 1m/s. The main science goals of SPIRou are the detection of habitable super-Earths around low-mass stars and the study of stellar magnetism of star at the early stages of their formation. Following a successful final design review in Spring 2014, SPIRou is now under construction and is scheduled to see first light in late 2017. We present an overview of key aspects of SPIRou's optical and mechanical design.

  1. Two telescopes ABCD electro-optic beam combiner based on lithium niobate for near infrared stellar interferometry

    NASA Astrophysics Data System (ADS)

    Heidmann, S.; Caballero, O.; Nolot, A.; Gineys, M.; Moulin, T.; Delboulbé, A.; Jocou, L.; Le Bouquin, J.-B.; Berger, J.-P.; Martin, G.

    2011-06-01

    Lithium Niobate (LN) based electro-optic modulators are well known in the optical communications field, due to their high bandwidth and deep rejection ratio [1]. These performances could be used in the field of astronomy for stellar interferometry in the mid-infrared domain [2]. With our partners from Photline Technologies, we have conceived, developed and characterized a 2T ABCD [3] beam combiner in the near-infrared (1.5μm, the H-band in astrophysics). The modulation scheme, presented below in Figure 1, allows to determine the fringe characteristics in a single shot measurement, without the need to externally scan the optical phase delay. Fine adjustment of the relative phase can be achieved using the electro-optic properties of the lithium niobate waveguides. In particular, the phase on each output can be electrically controlled and locked by using appropriate electrodes. These devices have to ensure modal filtering to reject optical aberrations of the wavefront and thus optimize the fringes contrast, which means that they have to be single mode through all the spectral range of interest. This also means that the couplers should be achromatic and balanced in order to optimize the fringe contrast. We will present results on global transmission, performance of the couplers and the electro-optic behavior of the device using monochromatic as well as wide spectral sources in the H-band.

  2. HONIR: an optical and near-infrared simultaneous imager, spectrograph, and polarimeter for the 1.5-m Kanata telescope

    NASA Astrophysics Data System (ADS)

    Akitaya, Hiroshi; Moritani, Yuki; Ui, Takahiro; Urano, Takeshi; Ohashi, Yuma; Kawabata, Koji S.; Nakashima, Asami; Sasada, Mahito; Sakimoto, Kiyoshi; Harao, Tatsuya; Miyamoto, Hisashi; Matsui, Rieko; Itoh, Ryosuke; Takaki, Katsutoshi; Ueno, Issei; Ohsugi, Takashi; Nakaya, Hidehiko; Yamashita, Takuya; Yoshida, Michitoshi

    2014-08-01

    We have developed an optical and near-infrared instrument HONIR (Hiroshima Optical and Near-InfraRed camera) with imaging, spectroscopy, and polarimetry capabilities in two (one optical and one near-infrared) bands simultaneously. Imaging capability with a field of view of 10 arcmin by 10 arcmin has been available since 2011, as reported in the previous SPIE conference. In addition, spectroscopic and polarimetric optical components (grisms, an Wollaston prism, a half-wave plate, and focal masks) were installed in the instrument, which enabled us to perform spectroscopy and linear polarization measurement by imaging polarimetry and spectro-polarimetry. Spectral resolution of R = λ/(triangle)λ ~ 440 - 800 is achieved in spectroscopy using a slit mask with an 1".3 width. In polarimetry, instrumental polarization is less than ~0.05 % with stability of better than ~0.05 %, which is sufficiently small to achieve an aimed accuracy of polarization measurement of ~0.1 % at primal observing wavelengths.

  3. Fresnel Interferometric Imager: ground-based prototype.

    PubMed

    Serre, Denis; Deba, Paul; Koechlin, Laurent

    2009-05-20

    The Fresnel Interferometric Imager is a space-based astronomical telescope project yielding milli-arcsecond angular resolution and high contrast images with loose manufacturing constraints. This optical concept involves diffractive focusing and formation flying: a first "primary optics" space module holds a large binary Fresnel array, and a second "focal module" holds optical elements and focal instruments that allow for chromatic dispersion correction. We have designed a reduced-size Fresnel Interferometric Imager prototype and made optical tests in our laboratory in order to validate the concept for future space missions. The primary module of this prototype consists of a square, 8 cm side, 23 m focal length Fresnel array. The focal module is composed of a diaphragmed small telescope used as "field lens," a small cophased diverging Fresnel zone lens that cancels the dispersion, and a detector. An additional module collimates the artificial targets of various shapes, sizes, and dynamic ranges to be imaged. We describe the experimental setup, different designs of the primary Fresnel array, and the cophased Fresnel zone lens that achieves rigorous chromatic correction. We give quantitative measurements of the diffraction limited performances and dynamic range on double sources. The tests have been performed in the visible domain, lambda = 400-700 nm. In addition, we present computer simulations of the prototype optics based on Fresnel propagation that corroborate the optical tests. This numerical tool has been used to simulate the large aperture Fresnel arrays that could be sent to space with diameters of 3 to 30 m, foreseen to operate from Lyman alpha (121 nm) to mid IR (25 microm).

  4. Nonclassical light in interferometric measurements

    NASA Technical Reports Server (NTRS)

    Ansari, N. A.; Difiore, L.; Romano, R.; Solimeno, S.; Zaccaria, F.; Manko, Margarita A.; Manko, Vladimir I.

    1995-01-01

    It is shown that the even and odd coherent light and other nonclassical states of light like superposition of coherent states with different phases may replace the squeezed light in an interferometric gravitational wave detector to increase its sensitivity.

  5. 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.

  6. The host galaxies and explosion sites of long-duration gamma ray bursts: Hubble Space Telescope near-infrared imaging

    NASA Astrophysics Data System (ADS)

    Lyman, J. D.; Levan, A. J.; Tanvir, N. R.; Fynbo, J. P. U.; McGuire, J. T. W.; Perley, D. A.; Angus, C. R.; Bloom, J. S.; Conselice, C. J.; Fruchter, > A. S.; Hjorth, J.; Jakobsson, P.; Starling, R. L. C.

    2017-01-01

    We present the results of a Hubble Space Telescope WFC3/F160W SNAPSHOT survey of the host galaxies of 39 long-duration gamma-ray bursts (LGRBs) at z < 3. We have non-detections of hosts at the locations of 4 bursts. Sufficient accuracy to astrometrically align optical afterglow images and determine the location of the LGRB within its host was possible for 31/35 detected hosts. In agreement with other work, we find the luminosity distribution of LGRB hosts is significantly fainter than that of a star formation rate-weighted field galaxy sample over the same redshift range, indicating LGRBs are not unbiasedly tracing the star formation rate. Morphologically, the sample of LGRB hosts are dominated by spiral-like or irregular galaxies. We find evidence for evolution of the population of LGRB hosts towards lower-luminosity, higher concentrated hosts at lower redshifts. Their half-light radii are consistent with other LGRB host samples where measurements were made on rest-frame UV observations. In agreement with recent work, we find their 80 per cent enclosed flux radii distribution to be more extended than previously thought, making them intermediate between core-collapse supernova (CCSN) and super-luminous supernova (SLSN) hosts. The galactocentric projected-offset distribution confirms LGRBs as centrally concentrated, much more so than CCSNe and similar to SLSNe. LGRBs are strongly biased towards the brighter regions in their host light distributions, regardless of their offset. We find a correlation between the luminosity of the LGRB explosion site and the intrinsic column density, NH, towards the burst.

  7. Pupil configurations for an interferometric TPF mission

    NASA Technical Reports Server (NTRS)

    Serabyn, G.; Mennesson, B.

    2003-01-01

    The primary goal of the proposed Terrestrial Planet Finder mission is the direct detection of radiation from potential terrestrial planets orbiting around nearby stars. However, the faintness of the expected signals leads to very stringent technical requirements on the optical performance. As a result, both of the candidate approaches currently under active development by the TPF project, infrared nulling interferometry with separated aperture telescopes, and optical coronagraphy with a large singl aperture telescope, require complex optical systems which push the state of the art.

  8. Prime Focus Spectrograph: A very wide-field, massively multiplexed, optical & near-infrared spectrograph for Subaru Telescope

    NASA Astrophysics Data System (ADS)

    TAMURA, NAOYUKI

    2015-08-01

    PFS (Prime Focus Spectrograph), a next generation facility instrument on Subaru, is a very wide-field, massively-multiplexed, and optical & near-infrared spectrograph. Exploiting the Subaru prime focus, 2400 reconfigurable fibers will be distributed in the 1.3 degree field. The spectrograph will have 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm at one exposure. The development of this instrument has been undertaken by the international collaboration at the initiative of Kavli IPMU. The project is now going into the construction phase aiming at system integration and on-sky commissioning in 2017-2018, and science operation in 2019. In parallel, the survey design has also been developed envisioning a Subaru Strategic Program (SSP) that spans roughly speaking 300 nights over 5 years. The major science areas are three-folds: Cosmology, galaxy/AGN evolution, and Galactic archaeology (GA). The cosmology program will be to constrain the nature of dark energy via a survey of emission line galaxies over a comoving volume of ~10 Gpc^3 in the redshift range of 0.8 < z < 2.4. In the GA program, radial velocities and chemical abundances of stars in the Milky Way, dwarf spheroidal galaxies, and M31 will be used to understand the past assembly histories of those galaxies and the structures of their dark matter halos. Spectra will be taken for ~1 million stars as faint as V = 22 therefore out to large distances from the Sun. For the extragalactic program, our simulations suggest the wide wavelength coverage of PFS will be particularly powerful in probing the galaxy populations and its clustering properties over a wide redshift range. We will conduct a survey of color-selected 1 < z < 2 galaxies and AGN over 20 square degrees down to J = 23.4, yielding a fair sample of galaxies with stellar masses above ˜10^10 solar masses. Further, PFS will also provide unique spectroscopic opportunities even in the era of Euclid, LSST

  9. Nulling Data Reduction and On-Sky Performance of the Large Binocular Telescope Interferometer

    NASA Technical Reports Server (NTRS)

    Defrere, D.; Hinz, P. M.; Mennesson, B.; Hoffman, W. F.; Millan-Gabet, R.; Skemer, A. J.; Bailey, V.; Danchi, W. C.; Downy, E. C.; Durney, O.; Grenz, P.; Hill, J. M.; McMahon, T. J.; Montoya, M.; Spalding, E.; Vaz, A.; Absil, O.; Arbo, P.; Roberge, A.

    2016-01-01

    The Large Binocular Telescope Interferometer (LBTI) is a versatile instrument designed for high angular resolution and high-contrast infrared imaging (1.5-13 micrometers). In this paper, we focus on the mid-infrared (8-13 micrometers) nulling mode and present its theory of operation, data reduction, and on-sky performance as of the end of the commissioning phase in 2015 March. With an interferometric baseline of 14.4 m, the LBTI nuller is specifically tuned to resolve the habitable zone of nearby main-sequence stars, where warm exozodiacal dust emission peaks. Measuring the exozodi luminosity function of nearby main-sequence stars is a key milestone to prepare for future exo-Earth direct imaging instruments. Thanks to recent progress in wavefront control and phase stabilization, as well as in data reduction techniques, the LBTI demonstrated in 2015 February a calibrated null accuracy of 0.05% over a 3 hr long observing sequence on the bright nearby A3V star Beta Leo. This is equivalent to an exozodiacal disk density of 15-30 zodi for a Sun-like star located at 10 pc, depending on the adopted disk model. This result sets a new record for high-contrast mid-infrared interferometric imaging and opens a new window on the study of planetary systems.

  10. Nulling Data Reduction and On-sky Performance of the Large Binocular Telescope Interferometer

    NASA Astrophysics Data System (ADS)

    Defrère, D.; Hinz, P. M.; Mennesson, B.; Hoffmann, W. F.; Millan-Gabet, R.; Skemer, A. J.; Bailey, V.; Danchi, W. C.; Downey, E. C.; Durney, O.; Grenz, P.; Hill, J. M.; McMahon, T. J.; Montoya, M.; Spalding, E.; Vaz, A.; Absil, O.; Arbo, P.; Bailey, H.; Brusa, G.; Bryden, G.; Esposito, S.; Gaspar, A.; Haniff, C. A.; Kennedy, G. M.; Leisenring, J. M.; Marion, L.; Nowak, M.; Pinna, E.; Powell, K.; Puglisi, A.; Rieke, G.; Roberge, A.; Serabyn, E.; Sosa, R.; Stapeldfeldt, K.; Su, K.; Weinberger, A. J.; Wyatt, M. C.

    2016-06-01

    The Large Binocular Telescope Interferometer (LBTI) is a versatile instrument designed for high angular resolution and high-contrast infrared imaging (1.5-13 μm). In this paper, we focus on the mid-infrared (8-13 μm) nulling mode and present its theory of operation, data reduction, and on-sky performance as of the end of the commissioning phase in 2015 March. With an interferometric baseline of 14.4 m, the LBTI nuller is specifically tuned to resolve the habitable zone of nearby main-sequence stars, where warm exozodiacal dust emission peaks. Measuring the exozodi luminosity function of nearby main-sequence stars is a key milestone to prepare for future exo-Earth direct imaging instruments. Thanks to recent progress in wavefront control and phase stabilization, as well as in data reduction techniques, the LBTI demonstrated in 2015 February a calibrated null accuracy of 0.05% over a 3 hr long observing sequence on the bright nearby A3V star β Leo. This is equivalent to an exozodiacal disk density of 15-30 zodi for a Sun-like star located at 10 pc, depending on the adopted disk model. This result sets a new record for high-contrast mid-infrared interferometric imaging and opens a new window on the study of planetary systems.

  11. The Antarctic Planet Interferometer and the potential for interferometric observations of extrasolar planets from Dome C Antarctica

    NASA Technical Reports Server (NTRS)

    Swain, M. R.; Foresto, V. Coude du; Vakili, F.

    2003-01-01

    We present a concept for the Antarctic Planet Interferometer (API) and discuss the improvements in interferometric detection and characterization of extrasolar planets by exploiting the unique potential of the best accessbile site on Earth for thermal infrared interferometry.

  12. 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.

  13. 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.

  14. CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey—The Hubble Space Telescope Observations, Imaging Data Products, and Mosaics

    NASA Astrophysics Data System (ADS)

    Koekemoer, Anton M.; Faber, S. M.; Ferguson, Henry C.; Grogin, Norman A.; Kocevski, Dale D.; Koo, David C.; Lai, Kamson; Lotz, Jennifer M.; Lucas, Ray A.; McGrath, Elizabeth J.; Ogaz, Sara; Rajan, Abhijith; Riess, Adam G.; Rodney, Steve A.; Strolger, Louis; Casertano, Stefano; Castellano, Marco; Dahlen, Tomas; Dickinson, Mark; Dolch, Timothy; Fontana, Adriano; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Huang, Kuang-Han; van der Wel, Arjen; Yan, Hao-Jing; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frédéric; Brown, Thomas M.; Caputi, Karina I.; Cassata, Paolo; Challis, Peter J.; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Roshan Cooray, Asantha; Croton, Darren J.; Daddi, Emanuele; Davé, Romeel; de Mello, Duilia F.; de Ravel, Loic; Dekel, Avishai; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Frazer, Chris; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Gruetzbauch, Ruth; Hartley, Will G.; Häussler, Boris; Herrington, Jessica; Hopkins, Philip F.; Huang, Jia-Sheng; Jha, Saurabh W.; Johnson, Andrew; Kartaltepe, Jeyhan S.; Khostovan, Ali A.; Kirshner, Robert P.; Lani, Caterina; Lee, Kyoung-Soo; Li, Weidong; Madau, Piero; McCarthy, Patrick J.; McIntosh, Daniel H.; McLure, Ross J.; McPartland, Conor; Mobasher, Bahram; Moreira, Heidi; Mortlock, Alice; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Nielsen, Jennifer L.; Niemi, Sami; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Snyder, Diana; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; Vargas, Carlos; Villforth, Carolin; Wagner, Cory R.; Wandro, Pat; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yun, Min S.

    2011-12-01

    This paper describes the Hubble Space Telescope imaging data products and data reduction procedures for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). This survey is designed to document the evolution of galaxies and black holes at z ≈ 1.5-8, and to study Type Ia supernovae at z > 1.5. Five premier multi-wavelength sky regions are selected, each with extensive multi-wavelength observations. The primary CANDELS data consist of imaging obtained in the Wide Field Camera 3 infrared channel (WFC3/IR) and the WFC3 ultraviolet/optical channel, along with the Advanced Camera for Surveys (ACS). The CANDELS/Deep survey covers ~125 arcmin2 within GOODS-N and GOODS-S, while the remainder consists of the CANDELS/Wide survey, achieving a total of ~800 arcmin2 across GOODS and three additional fields (Extended Groth Strip, COSMOS, and Ultra-Deep Survey). We summarize the observational aspects of the survey as motivated by the scientific goals and present a detailed description of the data reduction procedures and products from the survey. Our data reduction methods utilize the most up-to-date calibration files and image combination procedures. We have paid special attention to correcting a range of instrumental effects, including charge transfer efficiency degradation for ACS, removal of electronic bias-striping present in ACS data after Servicing Mission 4, and persistence effects and other artifacts in WFC3/IR. For each field, we release mosaics for individual epochs and eventual mosaics containing data from all epochs combined, to facilitate photometric variability studies and the deepest possible photometry. A more detailed overview of the science goals and observational design of the survey are presented in a companion paper.

  15. Infrared

    NASA Astrophysics Data System (ADS)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  16. THE INFRARED EYE OF THE WIDE-FIELD CAMERA 3 ON THE HUBBLE SPACE TELESCOPE REVEALS MULTIPLE MAIN SEQUENCES OF VERY LOW MASS STARS IN NGC 2808

    SciTech Connect

    Milone, A. P.; Aparicio, A.; Monelli, M. E-mail: aparicio@iac.es; and others

    2012-08-01

    We use images taken with the infrared channel of the Wide Field Camera 3 on the Hubble Space Telescope to study the multiple main sequences (MSs) of NGC 2808. Below the turnoff, the red, the middle, and the blue MS, previously detected from visual-band photometry, are visible over an interval of about 3.5 F160W magnitudes. The three MSs merge together at the level of the MS bend. At fainter magnitudes, the MS again splits into two components containing {approx}65% and {approx}35% of stars, with the most-populated MS being the bluest one. Theoretical isochrones suggest that the latter is connected to the red MS discovered in the optical color-magnitude diagram (CMD) and hence corresponds to the first stellar generation, having primordial helium and enhanced carbon and oxygen abundances. The less-populated MS in the faint part of the near-IR CMD is helium-rich and poor in carbon and oxygen, and it can be associated with the middle and the blue MS of the optical CMD. The finding that the photometric signature of abundance anti-correlation is also present in fully convective MS stars reinforces the inference that they have a primordial origin.

  17. Interferometric radar measurements

    NASA Astrophysics Data System (ADS)

    Smith, Ronald A.; Shipman, Mark; Holder, E. J.; Williams, James K.

    2002-08-01

    The United States Army Space and Missile Defense Command (USASMDC) has interest in a technology demonstration that capitalizes on investment in fire control and smart interceptor technologies that have matured beyond basic research. The concept SWORD (Short range missile defense With Optimized Radar Distribution) consists of a novel approach utilizing a missile interceptor and interferometric fire control radar. A hit-to-kill, closed-loop, command guidance scheme is planned that takes advantage of extremely accurate target and interceptor state vectors derived via the fire control radar. The fire control system has the capability to detect, track, and classify multiple threats in a tactical regime as well as simultaneously provide command guidance updates to multiple missile interceptors. The missile interceptor offers a cost reduction potential as well as an enhancement to the kinematics range and lethality over existing SHORAD systems. Additionally, the Radio Frequency (RF) guidance scheme offers increased battlefield weather performance. The Air Defense (AD) community, responding to current threat capabilities and trends, has identified an urgent need to have a capability to counter proliferated, low cost threats with a low cost-per-kill weapon system. The SWORD system will offer a solution that meets this need. The SWORD critical technologies will be identified including a detailed description of each. Validated test results and basic principles of operation will be presented to prove the merit of past investments. The Deputy Assistant Secretary of the Army for Research and Technology (DAS(R&T) has a three- year Science and Technology Program to evaluate the errors and proposed mitigation techniques associated with target spectral dispersion and range gate straddle. Preliminary bench-top experiment results will be presented in this paper.

  18. 180-GHz Interferometric Imager

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka P.; Lim, Boon H.; O'Dwyer, Ian J.; Soria, Mary M.; Owen, Heather R.; Gaier, Todd C.; Lambrigtsen, Bjorn, H.; Tanner, Alan B.; Ruf, Christopher

    2011-01-01

    A 180-GHz interferometric imager uses compact receiver modules, combined high- and low-gain antennas, and ASIC (application specific integrated circuit) correlator technology, enabling continuous, all-weather observations of water vapor with 25-km resolution and 0.3-K noise in 15 minutes of observation for numerical weather forecasting and tropical storm prediction. The GeoSTAR-II prototype instrument is broken down into four major subsystems: the compact, low-noise receivers; sub-array modules; IF signal distribution; and the digitizer/correlator. Instead of the single row of antennas adopted in GeoSTAR, this version has four rows of antennas on a coarser grid. This dramatically improves the sensitivity in the desired field of view. The GeoSTAR-II instrument is a 48-element, synthetic, thinned aperture radiometer operating at 165-183 GHz. The instrument has compact receivers integrated into tiles of 16 elements in a 4x4 arrangement. These tiles become the building block of larger arrays. The tiles contain signal distribution for bias controls, IF signal, and local oscillator signals. The IF signals are digitized and correlated using an ASIC correlator to minimize power consumption. Previous synthetic aperture imagers have used comparatively large multichip modules, whereas this approach uses chip-scale modules mounted on circuit boards, which are in turn mounted on the distribution manifolds. This minimizes the number of connectors and reduces system mass. The use of ASIC technology in the digitizers and correlators leads to a power reduction close to an order of magnitude.

  19. Weighting interferometric data for direct imaging

    NASA Astrophysics Data System (ADS)

    Boone, Frédéric

    2013-08-01

    The new generation interferometric arrays such as the Atacama Large Millimeter/submillimeter Array (ALMA) are composed of a large number of telescopes and their configurations are optimized for Fourier plane (a.k.a. uv-plane) coverage. As a consequence, solving for the missing information in the uv-plane is becoming less critical and the imaging algorithms can be revisited. The situation is getting similar to that encountered with single filled aperture telescopes and it is becoming possible to make images in a direct way. In this article a new weighting method is introduced to obtain "pseudo-clean" images without using prior information to solve for the Fourier transform of the source. This method is similar but not equivalent to the successive application of robust weighting and tapering at different scales. The idea is to weight the data to compensate for the imperfect distribution of natural weights in the uv-plane. The price to pay for this direct imaging technique is that the final point spread function (PSF or beam) may not follow a simple analytical shape such as a Gaussian (but this is also the case in optical astronomy) and some sensitivity is lost (but this is the case with any imaging algorithm in interferometry). Two parameters are introduced to control the trade-off between imaging quality and sensitivity, namely a threshold parameter and a coupling parameter. This method is applied to simulated ALMA observations with 16, 32 and 50 antennas. As expected this method is found to be more efficient with more antennas and for more compact configurations because the uv-plane coverage is more complete. With 50 antennas in compact configuration it is possible to reduce the amplitude of the inner sidelobes (outer sidelobes) by a factor >6 (>2) compared to natural weighting for ~10 % loss in sensitivity, leading to sidelobes lower than 1.6 % of the main lobe peak value. With 16 antennas only, the method can still be used to reduce the inner sidelobes of a

  20. Interferometric atmospheric refractive-index environmental monitor.

    PubMed

    Ludman, J E; Ludman, J J; Callahan, H; Caulfield, H J; Watt, D; Sampson, J L; Robinson, J; Davis, S; Hunt, A

    1995-06-20

    Long, open-path, outdoor interferometric measurement of the index of refraction as a function of wavelength (spectral refractivity) requires a number of innovations. These include active compensation for vibration and turbulence. The use of electronic compensation produces an electronic signal that is ideal for extracting data. This allows the appropriate interpretation of those data and the systematic and fast scanning of the spectrum by the use of bandwidths that are intermediate between lasers (narrow bandwidth) and white light (broad bandwidth). An Environmental Interferometer that incorporates these features should be extremely valuable in both pollutant detection and pollutant identification. Spectral refractivity measurements complement the information available from spectral absorption instruments (e.g., a Fourier-transform infrared spectrometer). The Environmental Interferometer currently uses an electronic compensating device with a 1-kHz response time, and therefore rapid spectral scans are feasibe so that it is possible to monitor the time evolution of pollutant events.

  1. Interferometric sensor for plant fluorescence

    NASA Astrophysics Data System (ADS)

    Georgieva, E.; Heaps, W. S.; Middleton, E. M.; Campbell, P. K. E.; Corp, L. A.

    2009-08-01

    We present preliminary design studies and modeling results for a new system for the assessment of vegetation photosynthetic function, especially carbon uptake. Plant health and carbon uptake efficiency are of key consideration in assessing global productivity, biomass, changes in land cover and carbon dioxide flux. Chlorophyll fluorescence (ChlF) measurements are critical for understanding photosynthetic functioning, plant environmental stress responses and direct assessments of plant health. Plant ChlF occurs predominately in two broad emission bands in the red and infrared regions of the spectrum. Unfortunately, the fluorescence signal from vegetation is much weaker than, and obscured by, the reflected signal. This limitation can be overcome by acquiring ChlF measurements in atmospheric absorption lines. The Interferometric Sensor for Plant Fluorescence (ISPF) will measure plant ChlF using the Fraunhofer Line Discrimination approach. Fabry-Perot (FP) etalons will be used to restrict the measurement to radiation in the Solar Fraunhofer lines (SFL). An advantage of the proposed sensor design is that it will collect measurements using two sets of SFL at the same time. This technique increases the optical throughput producing a larger signal to noise ratio (SNR). The instrument is designed to have two channels for two different spectral regions. Each channel will have two sub-channels, one defined by a prefilter (Reference, Ref) and the other having a tunable FP etalon. The first subchannel (the Ref) will cover a relatively broad spectral range to include at least two Fraunhofer lines but for which the fluorescence signal will represent only a small fraction of total reflected light. The second subchannel will use a FP interferometer to restrict the detected light to include only the selected SFL where the ChlF in-filling is significant. A small change in the fluorescence will then produce an insignificant change in the Ref subchannel but a relatively large change in

  2. Mobile radio interferometric geodetic systems

    NASA Technical Reports Server (NTRS)

    Macdoran, P. F.; Niell, A. E.; Ong, K. M.; Resch, G. M.; Morabito, D. D.; Claflin, E. S.; Lockhart, T. G.

    1978-01-01

    Operation of the Astronomical Radio Interferometric Earth Surveying (ARIES) in a proof of concept mode is discussed. Accuracy demonstrations over a short baseline, a 180 km baseline, and a 380 km baseline are documented. Use of ARIES in the Sea Slope Experiment of the National Geodetic Survey to study the apparent differences between oceanographic and geodetic leveling determinations of the sea surface along the Pacific Coast is described. Intergration of the NAVSTAR Global Positioning System and a concept called SERIES (Satellite Emission Radio Interferometric Earth Surveying) is briefly reviewed.

  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 2014 interferometric imaging beauty contest

    NASA Astrophysics Data System (ADS)

    Monnier, John D.; Berger, Jean-Philippe; Le Bouquin, Jean-Baptiste; Tuthill, Peter G.; Wittkowski, Markus; Grellmann, Rebekka; Müller, André; Renganswany, Sridhar; Hummel, Christian; Hofmann, Karl-Heinz; Schertl, Dieter; Weigelt, Gerd; Young, John; Buscher, David; Sanchez-Bermudez, Joel; Alberdi, Antxon; Schoedel, Rainer; Köhler, Rainer; Soulez, Ferréol; Thiébaut, Éric; Kluska, Jacques; Malbet, Fabien; Duvert, Gilles; Kraus, Stefan; Kloppenborg, Brian K.; Baron, Fabien; de Wit, Willem-Jan; Rivinius, Thomas; Merand, Antoine

    2014-07-01

    Here we present the results of the 6th biennial optical interferometry imaging beauty contest. Taking advantage of a unique opportunity, the red supergiant VY CMa and the Mira variable R Car were observed in the astronomical H-band with three 4-telescope configurations of the VLTI-AT array using the PIONIER instrument. The community was invited to participate in the subsequent image reconstruction and interpretation phases of the project. Ten groups submitted entries to the beauty contest, and we found reasonable consistency between images obtained from independent workers using quite different algorithms. We also found that significant differences existed between the submitted images, much greater than in past beauty contests that were all based on simulated data. A novel crowd-sourcing" method allowed consensus median images to be constructed, filtering likely artifacts and retaining real features." We definitively detect strong spots on the surfaces of both stars as well as distinct circumstellar shells of emission (likely water/CO) around R Car. In a close contest, Joel Sanchez (IAA-CSIC/Spain) was named the winner of the 2014 interferometric imaging beauty contest. This process has shown that new comers" can use publicly-available imaging software to interpret VLTI/PIONIER imaging data, as long as sufficient observations are taken to have complete uv coverage { a luxury that is often missing. We urge proposers to request adequate observing nights to collect sufficient data for imaging and for time allocation committees to recognise the importance of uv coverage for reliable interpretation of interferometric data. We believe that the result of the proposed broad international project will contribute to inspiring trust in the image reconstruction processes in optical interferometry.

  5. Preliminary LISA Telescope Spacer Design

    NASA Technical Reports Server (NTRS)

    Livas, J.; Arsenovic, P.; Catellucci, K.; Generie, J.; Howard, J.; Stebbins, R. T.

    2010-01-01

    The Laser Interferometric Space Antenna (LISA) mission observes gravitational waves by measuring the separations between freely floating proof masses located 5 million kilometers apart with an accuracy of approximately 10 picometers. The separations are measured interferometrically. The telescope is an afocal Cassegrain style design with a magnification of 80x. The entrance pupil has a 40 cm diameter and will either be centered on-axis or de-centered off-axis to avoid obscurations. Its two main purposes are to transform the small diameter beam used on the optical bench to a diffraction limited collimated beam to efficiently transfer the metrology laser between spacecraft, and to receive the incoming light from the far spacecraft. It transmits and receives simultaneously. The basic optical design and requirements are well understood for a conventional telescope design for imaging applications, but the LISA design is complicated by the additional requirement that the total optical path through the telescope must remain stable at the picometer level over the measurement band during the mission to meet the measurement accuracy. This poster describes the requirements for the telescope and the preliminary work that has been done to understand the materials and mechanical issues associated with the design of a passive metering structure to support the telescope and to maintain the spacing between the primary and secondary mirrors in the LISA on-orbit environment. This includes the requirements flowdown from the science goals, thermal modeling of the spacecraft and telescope to determine the expected temperature distribution,layout options for the telescope including an on- and off-axis design, and plans for fabrication and testing.

  6. 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.

  7. A SPITZER SPACE TELESCOPE FAR-INFRARED SPECTRAL ATLAS OF COMPACT SOURCES IN THE MAGELLANIC CLOUDS. II. THE SMALL MAGELLANIC CLOUD

    SciTech Connect

    Van Loon, Jacco Th.; Oliveira, Joana M.; Gordon, Karl D.; Sloan, G. C.; Engelbracht, C. W.

    2010-04-15

    We present far-infrared spectra, {lambda} = 52-93 {mu}m, obtained with the Spitzer Space Telescope in the spectral energy distribution mode of its Multiband Imaging Photometer for Spitzer instrument, of a selection of luminous compact far-infrared sources in the Small Magellanic Cloud (SMC). These comprise nine young stellar objects (YSOs), the compact H II region N 81 and a similar object within N 84, and two red supergiants (RSGs). We use the spectra to constrain the presence and temperature of cool dust and the excitation conditions within the neutral and ionized gas, in the circumstellar environments and interfaces with the surrounding interstellar medium. We compare these results with those obtained in the Large Magellanic Cloud (LMC). The spectra of the sources in N 81 (of which we also show the Infrared Space Observatory-Long-wavelength Spectrograph spectrum between 50 and 170 {mu}m) and N 84 both display strong [O I] {lambda}63 {mu}m and [O III] {lambda}88 {mu}m fine-structure line emission. We attribute these lines to strong shocks and photo-ionized gas, respectively, in a 'champagne flow' scenario. The nitrogen content of these two H II regions is very low, definitely N(N)/N(O) < 0.04 but possibly as low as N(N)/N(O) < 0.01. Overall, the oxygen lines and dust continuum are weaker in star-forming objects in the SMC than in the LMC. We attribute this to the lower metallicity of the SMC compared to that of the LMC. While the dust mass differs in proportion to metallicity, the oxygen mass differs less; both observations can be reconciled with higher densities inside star-forming cloud cores in the SMC than in the LMC. The dust in the YSOs in the SMC is warmer (37-51 K) than in comparable objects in the LMC (32-44 K). We attribute this to the reduced shielding and reduced cooling at the low metallicity of the SMC. On the other hand, the efficiency of the photo-electric effect to heat the gas is found to be indistinguishable to that measured in the same manner

  8. INFRARED TRANSMISSION SPECTROSCOPY OF THE EXOPLANETS HD 209458b AND XO-1b USING THE WIDE FIELD CAMERA-3 ON THE HUBBLE SPACE TELESCOPE

    SciTech Connect

    Deming, Drake; Wilkins, Ashlee; McCullough, Peter; Crouzet, Nicolas; Burrows, Adam; Fortney, Jonathan J.; Agol, Eric; Dobbs-Dixon, Ian; Madhusudhan, Nikku; Desert, Jean-Michel; Knutson, Heather A.; Line, Michael; Gilliland, Ronald L.; Haynes, Korey; Magic, Zazralt; Mandell, Avi M.; Clampin, Mark; Ranjan, Sukrit; Charbonneau, David; Seager, Sara; and others

    2013-09-10

    Exoplanetary transmission spectroscopy in the near-infrared using the Hubble Space Telescope (HST) NICMOS is currently ambiguous because different observational groups claim different results from the same data, depending on their analysis methodologies. Spatial scanning with HST/WFC3 provides an opportunity to resolve this ambiguity. We here report WFC3 spectroscopy of the giant planets HD 209458b and XO-1b in transit, using spatial scanning mode for maximum photon-collecting efficiency. We introduce an analysis technique that derives the exoplanetary transmission spectrum without the necessity of explicitly decorrelating instrumental effects, and achieves nearly photon-limited precision even at the high flux levels collected in spatial scan mode. Our errors are within 6% (XO-1) and 26% (HD 209458b) of the photon-limit at a resolving power of {lambda}/{delta}{lambda} {approx} 70, and are better than 0.01% per spectral channel. Both planets exhibit water absorption of approximately 200 ppm at the water peak near 1.38 {mu}m. Our result for XO-1b contradicts the much larger absorption derived from NICMOS spectroscopy. The weak water absorption we measure for HD 209458b is reminiscent of the weakness of sodium absorption in the first transmission spectroscopy of an exoplanet atmosphere by Charbonneau et al. Model atmospheres having uniformly distributed extra opacity of 0.012 cm{sup 2} g{sup -1} account approximately for both our water measurement and the sodium absorption. Our results for HD 209458b support the picture advocated by Pont et al. in which weak molecular absorptions are superposed on a transmission spectrum that is dominated by continuous opacity due to haze and/or dust. However, the extra opacity needed for HD 209458b is grayer than for HD 189733b, with a weaker Rayleigh component.

  9. Herschel Far-infrared Photometry of the Swift Burst Alert Telescope Active Galactic Nuclei Sample of the Local Universe. I. PACS Observations

    NASA Astrophysics Data System (ADS)

    Meléndez, M.; Mushotzky, R. F.; Shimizu, T. T.; Barger, A. J.; Cowie, L. L.

    2014-10-01

    Far-Infrared (FIR) photometry from the Photodetector Array Camera and Spectrometer on the Herschel Space Observatory is presented for 313 nearby, hard X-ray selected galaxies from the 58 month Swift Burst Alert Telescope (BAT) Active Galactic Nuclei catalog. The present data do not distinguish between the FIR luminosity distributions at 70 and 160 μm for Seyfert 1 and Seyfert 2 galaxies. This result suggests that if the FIR emission is from the nuclear obscuring material surrounding the accretion disk, then it emits isotropically, independent of orientation. Alternatively, a significant fraction of the 70 and 160 μm luminosity could be from star formation, independent of active galactic nucleus (AGN) type. Using a non-parametric test for partial correlation with censored data, we find a statistically significant correlation between the AGN intrinsic power (in the 14-195 keV band) and the FIR emission at 70 and 160 μm for Seyfert 1 galaxies. We find no correlation between the 14-195 keV and FIR luminosities in Seyfert 2 galaxies. The observed correlations suggest two possible scenarios: (1) if we assume that the FIR luminosity is a good tracer of star formation, then there is a connection between star formation and the AGN at sub-kiloparsec scales, or (2) dust heated by the AGN has a statistically significant contribution to the FIR emission. Using a Spearman rank-order analysis, the 14-195 keV luminosities for the Seyfert 1 and 2 galaxies are weakly statistically correlated with the F 70/F 160 ratios. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  10. Herschel far-infrared photometry of the swift burst alert telescope active galactic nuclei sample of the local universe. I. PACS observations

    SciTech Connect

    Meléndez, M.; Mushotzky, R. F.; Shimizu, T. T.; Barger, A. J.; Cowie, L. L.

    2014-10-20

    Far-Infrared (FIR) photometry from the Photodetector Array Camera and Spectrometer on the Herschel Space Observatory is presented for 313 nearby, hard X-ray selected galaxies from the 58 month Swift Burst Alert Telescope (BAT) Active Galactic Nuclei catalog. The present data do not distinguish between the FIR luminosity distributions at 70 and 160 μm for Seyfert 1 and Seyfert 2 galaxies. This result suggests that if the FIR emission is from the nuclear obscuring material surrounding the accretion disk, then it emits isotropically, independent of orientation. Alternatively, a significant fraction of the 70 and 160 μm luminosity could be from star formation, independent of active galactic nucleus (AGN) type. Using a non-parametric test for partial correlation with censored data, we find a statistically significant correlation between the AGN intrinsic power (in the 14-195 keV band) and the FIR emission at 70 and 160 μm for Seyfert 1 galaxies. We find no correlation between the 14-195 keV and FIR luminosities in Seyfert 2 galaxies. The observed correlations suggest two possible scenarios: (1) if we assume that the FIR luminosity is a good tracer of star formation, then there is a connection between star formation and the AGN at sub-kiloparsec scales, or (2) dust heated by the AGN has a statistically significant contribution to the FIR emission. Using a Spearman rank-order analysis, the 14-195 keV luminosities for the Seyfert 1 and 2 galaxies are weakly statistically correlated with the F {sub 70}/F {sub 160} ratios.

  11. Herschel far-infrared photometry of the Swift Burst Alert Telescope active galactic nuclei sample of the local universe - II. SPIRE observations

    NASA Astrophysics Data System (ADS)

    Shimizu, T. Taro; Meléndez, Marcio; Mushotzky, Richard F.; Koss, Michael J.; Barger, Amy J.; Cowie, Lennox L.

    2016-03-01

    We present far-infrared (FIR) and submillimetre photometry from the Herschel Space Observatory's Spectral and Photometric Imaging Receiver (SPIRE) for 313 nearby (z < 0.05) active galactic nuclei (AGN). We selected AGN from the 58 month Swift Burst Alert Telescope (BAT) catalogue, the result of an all-sky survey in the 14-195 keV energy band, allowing for a reduction in AGN selection effects due to obscuration and host galaxy contamination. We find 46 per cent (143/313) of our sample is detected at all three wavebands and combined with our Photoconductor Array Camera and Spectrometer (PACS) observations represents the most complete FIR spectral energy distributions of local, moderate-luminosity AGN. We find no correlation among the 250, 350, and 500 μm luminosities with 14-195 keV luminosity, indicating the bulk of the FIR emission is not related to the AGN. However, Seyfert 1s do show a very weak correlation with X-ray luminosity compared to Seyfert 2s and we discuss possible explanations. We compare the SPIRE colours (F250/F350 and F350/F500) to a sample of normal star-forming galaxies, finding the two samples are statistically similar, especially after matching in stellar mass. But a colour-colour plot reveals a fraction of the Herschel-BAT AGN are displaced from the normal star-forming galaxies due to excess 500 μm emission (E500). Our analysis shows E500 is strongly correlated with the 14-195 keV luminosity and 3.4/4.6 μm flux ratio, evidence the excess is related to the AGN. We speculate these sources are experiencing millimetre excess emission originating in the corona of the accretion disc.

  12. Optical aperture synthesis with electronically connected telescopes.

    PubMed

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D

    2015-04-16

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths.

  13. Two-Wavelength Interferometric Keratometer

    NASA Technical Reports Server (NTRS)

    Hochberg, Eric; Page, Norman

    1991-01-01

    Proposed interferometric keratometer measures shapes of corneas without touching them. Used to test strongly aspherical optics. Resembling present commercial lens-testing interferometers, generates interferograms representative of deviation of surfaces under test from sphericity. Such interferograms used to generate contour maps of surfaces. Measures corneal topography to diameters as large as 12 mm.

  14. 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'...

  15. Infrared: Beyond the Visible

    NASA Video Gallery

    Infrared: Beyond the Visible, is a fast, fun look at why infrared light matters to astronomy, and what the Webb Space Telescope will search for once it's in orbit. Caption file available at: http:/...

  16. Interferometric IR observations: a diversity of dusty AGN tori

    NASA Astrophysics Data System (ADS)

    Burtscher, Leonard

    Interferometric observations in the infrared have resolved dusty structures on parsec and sub-parsec scales in more than two dozen AGNs by now -- a giant leap when considering that the first infrared interferometric observation of an extragalactic object is only about 10 years old. Since then, studies have confirmed the existence of dust in AGNs at its sublimation radius and have clearly dismissed models of very extended tori. Individual, well studied sources have been instrumental to reveal the complexity of these parsec-scale structures and statistical studies have shown a perplexing diversity in the population as a whole. Surprisingly, the diversity does not seem to follow the expected bimodality between optical type 1 and type 2 AGNs -- which are thought to be just face-on and edge-on tori. This central premise of viewing-angle dependent unified models is challenged if not dismissed by interferometric observations. The next step in understanding the AGN phenomenon -- beyond unification aspects -- is now to combine multi-scale observations with multi-scale simulations to constrain the physical processes driving the feeding and feedback of AGNs.

  17. A SPITZER SPACE TELESCOPE FAR-INFRARED SPECTRAL ATLAS OF COMPACT SOURCES IN THE MAGELLANIC CLOUDS. I. THE LARGE MAGELLANIC CLOUD

    SciTech Connect

    Van Loon, Jacco Th.; Oliveira, Joana M.; Gordon, Karl D.; Meixner, Margaret; Shiao, Bernie; Boyer, Martha L.; Kemper, F.; Woods, Paul M.; Tielens, A. G. G. M.; Marengo, Massimo; Indebetouw, Remy; Chen, C.-H. Rosie; Sloan, G. C.

    2010-01-15

    We present far-infrared spectra, {lambda} = 52-93 {mu}m, obtained with the Spitzer Space Telescope in the spectral energy distribution mode of its MIPS instrument, of a representative sample of the most luminous compact far-infrared sources in the Large Magellanic Cloud (LMC). These include carbon stars, OH/IR asymptotic giant branch (AGB) stars, post-AGB objects and planetary nebulae, the R CrB-type star HV 2671, the OH/IR red supergiants (RSGs) WOH G064 and IRAS 05280 - 6910, the three B[e] stars IRAS 04530 - 6916, R 66 and R 126, the Wolf-Rayet star Brey 3a, the luminous blue variable (LBV) R 71, the supernova remnant N 49, a large number of young stellar objects (YSOs), compact H II regions and molecular cores, and a background galaxy at a redshift z {approx_equal} 0.175. We use the spectra to constrain the presence and temperature of cold dust and the excitation conditions and shocks within the neutral and ionized gas, in the circumstellar environments and interfaces with the surrounding interstellar medium (ISM). First, we introduce a spectral classification scheme. Then, we measure line strengths, dust temperatures, and IR luminosities. Objects associated with star formation are readily distinguished from evolved stars by their cold dust and/or fine-structure lines. Evolved stars, including the LBV R 71, lack cold dust except in some cases where we argue that this is swept-up ISM. This leads to an estimate of the duration of the prolific dust-producing phase ('superwind') of several thousand years for both RSGs and massive AGB stars, with a similar fractional mass loss experienced despite the different masses. We tentatively detect line emission from neutral oxygen in the extreme RSG WOH G064, which suggests a large dust-free cavity with implications for wind driving. In N 49, the shock between the supernova ejecta and ISM is revealed in spectacular fashion by its strong [O I] {lambda}63 {mu}m emission and possibly water vapor; we estimate that 0.2 M {sub

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. The history of radio telescopes, 1945-1990

    NASA Astrophysics Data System (ADS)

    Sullivan, Woodruff T.

    2009-08-01

    Forged by the development of radar during World War II, radio astronomy revolutionized astronomy during the decade after the war. A new universe was revealed, centered not on stars and planets, but on the gas between the stars, on explosive sources of unprecedented luminosity, and on hundreds of mysterious discrete sources with no optical identifications. Using “radio telescopes” that looked nothing like traditional (optical) telescopes, radio astronomers were a very different breed from traditional (optical) astronomers. This pathbreaking of radio astronomy also made it much easier for later “astronomies” and their “telescopes” (X-ray, ultraviolet, infrared, gamma-ray) to become integrated into astronomy after the launch of the space age in the 1960s. This paper traces the history of radio telescopes from 1945 through about 1990, from the era of converted small-sized, military radar antennas to that of large interferometric arrays connected by complex electronics and computers; from the era of strip-chart recordings measured by rulers to powerful computers and display graphics; from the era of individuals and small groups building their own equipment to that of Big Science, large collaborations and national observatories.

  3. Development of laser interferometric high-precision geometry monitor for JASMINE

    NASA Astrophysics Data System (ADS)

    Niwa, Yoshito; Arai, Koji; Ueda, Akitoshi; Sakagami, Masaaki; Gouda, Naoteru; Kobayashi, Yukiyasu; Yamada, Yoshiyuki; Yano, Taihei

    2008-07-01

    The telescope geometry of JASMINE should be stabilized and monitored with the accuracy of about 10 to 100 picometer or 10 to 100 picoradian in root-mean-square over about 10 hours. For this purpose, a high-precision interferometric laser metrology system is employed. One of useful techniques for measuring displacements in extremely minute scales is the heterodyne interferometrical method. Experiment for verification of multi degree of freedom measurement was performed and mirror motions were successfully monitored with three degree of freedom.

  4. An overview of instrumentation for the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark

    2008-07-01

    An overview of instrumentation for the Large Binocular Telescope is presented. Optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (27' × 27') mosaic CCD imagers at the prime focus, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam blue-red optimized long-slit spectrographs mounted at the straight-through F/15 Gregorian focus incorporating multiple slit masks for multi-object spectroscopy over a 6 field and spectral resolutions of up to 8000. Infrared instrumentation includes the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCIFER), a modular near-infrared (0.9-2.5 μm) imager and spectrograph pair mounted at a bent interior focal station and designed for seeing-limited (FOV: 4' × 4') imaging, long-slit spectroscopy, and multi-object spectroscopy utilizing cooled slit masks and diffraction limited (FOV: 0.5' × 0.5') imaging and long-slit spectroscopy. Strategic instruments under development for the remaining two combined focal stations include an interferometric cryogenic beam combiner with near-infrared and thermal-infrared instruments for Fizeau imaging and nulling interferometry (LBTI) and an optical bench near-infrared beam combiner utilizing multi-conjugate adaptive optics for high angular resolution and sensitivity (LINC-NIRVANA). In addition, a fiber-fed bench spectrograph (PEPSI) capable of ultra high resolution spectroscopy and spectropolarimetry (R = 40,000-300,000) will be available as a principal investigator instrument. The availability of all these instruments mounted simultaneously on the LBT permits unique science, flexible scheduling, and improved operational support.

  5. An overview of instrumentation for the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark

    2010-07-01

    An overview of instrumentation for the Large Binocular Telescope is presented. Optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (27 × 27) mosaic CCD imagers at the prime focus, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam blue-red optimized long-slit spectrographs mounted at the straight-through F/15 Gregorian focus incorporating multiple slit masks for multi-object spectroscopy over a 6 field and spectral resolutions of up to 8000. Infrared instrumentation includes the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCIFER), a modular near-infrared (0.9-2.5 μm) imager and spectrograph pair mounted at a bent interior focal station and designed for seeing-limited (FOV: 4 × 4) imaging, long-slit spectroscopy, and multi-object spectroscopy utilizing cooled slit masks and diffraction limited (FOV: 0.5 × 0.5) imaging and long-slit spectroscopy. Strategic instruments under development for the remaining two combined focal stations include an interferometric cryogenic beam combiner with near-infrared and thermal-infrared instruments for Fizeau imaging and nulling interferometry (LBTI) and an optical bench near-infrared beam combiner utilizing multi-conjugate adaptive optics for high angular resolution and sensitivity (LINC-NIRVANA). In addition, a fiber-fed bench spectrograph (PEPSI) capable of ultra high resolution spectroscopy and spectropolarimetry (R = 40,000-300,000) will be available as a principal investigator instrument. The availability of all these instruments mounted simultaneously on the LBT permits unique science, flexible scheduling, and improved operational support. Over the past two years the LBC and the first LUCIFER instrument have been brought into routine scientific operation and MODS1 commissioning is set to begin in the fall of 2010.

  6. An overview of instrumentation for the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark

    2004-09-01

    An overview of instrumentation for the Large Binocular Telescope is presented. Optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (27'x 27') UB/VRI optimized mosaic CCD imagers at the prime focus, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam blue-red optimized long-slit spectrographs mounted at the straight-through F/15 Gregorian focus incorporating multiple slit masks for multi-object spectroscopy over a 6\\arcmin\\ field and spectral resolutions of up to 8000. Infrared instrumentation includes the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCIFER), a modular near-infrared (0.9-2.5 μm) imager and spectrograph pair mounted at a bent interior focal station and designed for seeing-limited (FOV: 4'x 4') imaging, long-slit spectroscopy, and multi-object spectroscopy utilizing cooled slit masks and diffraction limited (FOV: 0'.5 x 0'.5) imaging and long-slit spectroscopy. Strategic instruments under development for the remaining two combined focal stations include an interferometric cryogenic beam combiner with near-infrared and thermal-infrared instruments for Fizeau imaging and nulling interferometry (LBTI) and an optical bench beam combiner with visible and near-infrared imagers utilizing multi-conjugate adaptive optics for high angular resolution and sensitivity (LINC/NIRVANA). In addition, a fiber-fed bench spectrograph (PEPSI) capable of ultra high resolution spectroscopy and spectropolarimetry (R = 40,000-300,000) will be available as a principal investigator instrument. The availability of all these instruments mounted simultaneously on the LBT permits unique science, flexible scheduling, and improved operational support.

  7. An overview of instrumentation for the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark

    2006-06-01

    An overview of instrumentation for the Large Binocular Telescope is presented. Optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (27' × 27') mosaic CCD imagers at the prime focus, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam blue-red optimized long-slit spectrographs mounted at the straight-through F/15 Gregorian focus incorporating multiple slit masks for multi-object spectroscopy over a 6' field and spectral resolutions of up to 8000. Infrared instrumentation includes the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCIFER), a modular near-infrared (0.9-2.5 μm) imager and spectrograph pair mounted at a bent interior focal station and designed for seeing-limited (FOV: 4' × 4') imaging, long-slit spectroscopy, and multi-object spectroscopy utilizing cooled slit masks and diffraction limited (FOV: 0'.5 × 0'.5) imaging and long-slit spectroscopy. Strategic instruments under development for the remaining two combined focal stations include an interferometric cryogenic beam combiner with near-infrared and thermal-infrared instruments for Fizeau imaging and nulling interferometry (LBTI) and an optical bench near-infrared beam combiner utilizing multi-conjugate adaptive optics for high angular resolution and sensitivity (LINC-NIRVANA). In addition, a fiber-fed bench spectrograph (PEPSI) capable of ultra high resolution spectroscopy and spectropolarimetry (R = 40,000-300,000) will be available as a principal investigator instrument. The availability of all these instruments mounted simultaneously on the LBT permits unique science, flexible scheduling, and improved operational support.

  8. Registration of interferometric SAR images

    NASA Technical Reports Server (NTRS)

    Lin, Qian; Vesecky, John F.; Zebker, Howard A.

    1992-01-01

    Interferometric synthetic aperture radar (INSAR) is a new way of performing topography mapping. Among the factors critical to mapping accuracy is the registration of the complex SAR images from repeated orbits. A new algorithm for registering interferometric SAR images is presented. A new figure of merit, the average fluctuation function of the phase difference image, is proposed to evaluate the fringe pattern quality. The process of adjusting the registration parameters according to the fringe pattern quality is optimized through a downhill simplex minimization algorithm. The results of applying the proposed algorithm to register two pairs of Seasat SAR images with a short baseline (75 m) and a long baseline (500 m) are shown. It is found that the average fluctuation function is a very stable measure of fringe pattern quality allowing very accurate registration.

  9. POST: a polar stratospheric telescope

    NASA Astrophysics Data System (ADS)

    Ford, Holland C.; Bely, Pierre Y.; Bally, John; Crocker, James H.; Dopita, Mike; Tilley, James N.; Allen, Ronald; Bartko, Frank; White, Richard L.; Burg, Richard; Burrows, Christopher J.; Clampin, Mark; Harper, Doyal A.; Illingworth, Garth; McCray, Richard; Meyer, Stephan; Mould, Jeremy; Norman, Colin

    1994-06-01

    The lower stratosphere in the polar regions offers conditions for observation in the near-infrared comparable to those obtained from space. We describe a concept for a 6-meter, diluted aperture, near-infrared telescope carried by a tethered aerostat flying at 12 km altitude, to serve as a testbed for future space astronomical observatories while producing frontier science.

  10. Practical Issues Related to the Interferometric Imaging of Geosats

    NASA Astrophysics Data System (ADS)

    Schmitt, H.; Restaino, S.; Mozurkewich, D.; Mason, J.; Bock, K.; Dank, J.; Armstrong, J. T.; Baines, E.; Feller, G.

    2014-09-01

    Imaging geostationary satellites from the ground is an important Space Situational Awareness diagnostic tool that will require the use of optical interferometry. We developed a series of imaging and data quality simulations that allow us to investigate issues related to the interferometric imaging of such targets. We will discuss the number of baselines and sampling density needed to achieve different resolutions. We will also discuss some issues that are specific to the problem of imaging geosats, such as the size of the target relative to the resolving power of a single telescope in the interferometer, the precision needed in order to determine and correct for different sources of delay (atmospheric turbulence, telescope and target motion), and retrieve phase information from multiple baselines. The results presented here will be important to guide the design of future optical interferometers dedicated to the imaging of geosats.

  11. 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.

  12. James Webb Space Telescope Project (JWST) Overview

    NASA Technical Reports Server (NTRS)

    Dutta, Mitra

    2008-01-01

    This presentation provides an overview of the James Webb Space Telescope (JWST) Project. The JWST is an infrared telescope designed to collect data in the cosmic dark zone. Specifically, the mission of the JWST is to study the origin and evolution of galaxies, stars and planetary systems. It is a deployable telescope with a 6.5 m diameter, segmented, adjustable primary mirror. outfitted with cryogenic temperature telescope and instruments for infrared performance. The JWST is several times more sensitive than previous telescope and other photographic and electronic detection methods. It hosts a near infrared camera, near infrared spectrometer, mid-infrared instrument and a fine guidance sensor. The JWST mission objection and architecture, integrated science payload, instrument overview, and operational orbit are described.

  13. Telescope Systems for Balloon-Borne Research

    NASA Technical Reports Server (NTRS)

    Swift, C. (Editor); Witteborn, F. C. (Editor); Shipley, A. (Editor)

    1974-01-01

    The proceedings of a conference on the use of balloons for scientific research are presented. The subjects discussed include the following: (1) astronomical observations with balloon-borne telescopes, (2) orientable, stabilized balloon-borne gondola for around-the-world flights, (3) ultraviolet stellar spectrophotometry from a balloon platform, (4) infrared telescope for balloon-borne infrared astronomy, and (5) stabilization, pointing, and command control of balloon-borne telescopes.

  14. Infrared astronomy

    NASA Technical Reports Server (NTRS)

    Gillett, Frederick; Houck, James; Bally, John; Becklin, Eric; Brown, Robert Hamilton; Draine, Bruce; Frogel, Jay; Gatley, Ian; Gehrz, Robert; Hildebrand, Roger

    1991-01-01

    The decade of 1990's presents an opportunity to address fundamental astrophysical issues through observations at IR wavelengths made possible by technological and scientific advances during the last decade. The major elements of recommended program are: the Space Infrared Telescope Facility (SIRTF), the Stratospheric Observatory For Infrared Astronomy (SOFIA) and the IR Optimized 8-m Telescope (IRO), a detector and instrumentation program, the SubMilliMeter Mission (SMMM), the 2 Microns All Sky Survey (2MASS), a sound infrastructure, and technology development programs. Also presented are: perspective, science opportunities, technical overview, project recommendations, future directions, and infrastructure.

  15. The Spitzer Space Telescope Mission

    NASA Technical Reports Server (NTRS)

    Werner, M. W.

    2005-01-01

    The Spitzer Space Telescope, NASA's Great Observatory for infrared astronomy, was launched 2003 August 25 and is returning excellent scientific data from its Earth-trailing solar orbit. Spitzer combines the intrinsic sensitivity achievable with a cryogenic telescope in space with the great imaging and spectroscopic power of modern detector arrays to provide the user community with huge gains in capability for exploration of the cosmos in the infrared. The observatory systems are largely performing as expected, and the projected cryogenic lifetime is about five years. Spitzer is thus both a scientific and a technical precursor to the infrared astronomy missions of the future. This very brief paper refers interested readers to several sets of recent publications which describe both the scientific and the technical features of Spitzer in detail. Note that, until 2003 December, Spitzer was known as the Space Infrared Telescope Facility (SIRTF).

  16. A New Spectroscopic and Interferometric Study of the Young Stellar Object V645 Cyg

    NASA Technical Reports Server (NTRS)

    Miroshinichenko, A. S.; Hofmann, K.-H.; Schertl, D.; Weigelt, G.; Kraus, S.; Manset, N.; Balega, Y. Y.; Klochkova, V. G.; Rudy, R. J.; Lynch, D. K.; Mazuk, S.; Venturini, C. C.; Grankin, K. N.; Puetter, R. C.; Perry, R. B.

    2009-01-01

    Aims. We present the results of high-resolution optical spectroscopy, low-resolution near-IR spectroscopy and near-infrared speckle interferometry of the massive young stellar object candidate V645 Cyg that were taken in order to refine its fundamental parameters and properties of its circumstellar envelope. Methods. Speckle interferometry in the H- and K-bands and an optical spectrum in the range 5200-6680 A with a spectral resolving power of R = 60000 were obtained at the 6 m telescope of the Russian Academy of Sciences. Another optical spectrum in the range 4300-10500 A with R = 79000 was obtained at the 3.6m CFHT. A low-resolution spectrum in the ranges 0.46-1.4 and 1.4-2.5 microns with a R approx. 800 and approx. 700, respectively, were obtained at the 3m Shain telescope of the Lick Observatory. Results. Using a new kinematic method based on non-linear modeling of the neutral hydrogen density profile in the direction toward the object, we suggest a new a distance D = 4.2+/-0.2 kpc. We also suggest a new estimate for the star's effective temperature, T(sub eff) approx. 25000 K. We have resolved the object in both H- and K-bands. Using a two-component ring fit, we derived a compact component size of 18 mas and 15 mas in the H- and K-band, respectively, which correspond to 37 and 33 AU at the new distance. Analysis of our and previously published data shows a approx. 2 mag drop of the near-infrared brightness of V645 Cyg in the beginning of the 1980 s. At the same time, the cometary nebular condensation N1 seems to fade in this wavelength range with respect to the N0 object, which represent the star with a nearly pole-on optically-thick disk and an optically-thin envelope. Conclusions. We conclude that V645 Cyg is a young massive main-sequence star, which recently emerged from its cocoon. and already passed the protostellar accretion stage. The presence of accretion is not necessary to account for the high observed luminosity of (2.6) x 10(exp 4) Solar Mass

  17. Infrared astronomy from the Moon

    NASA Technical Reports Server (NTRS)

    Harwit, Martin

    1994-01-01

    The purpose of this paper is to exhibit the advantages and limitations to infrared astronomical observations form the moon. The most obvious apparent advantage is the lack of a lunar atmosphere; radiation arriving from the universe is neither extinguished nor refracted as it approaches the lunar surface. However, the Earth's atmosphere's protection against cosmic rays is also lost, and infrared detectors are highly sensitive to irradiation by energetic particles. A second apparent advantage is the relative ease with which beams from an array of telescopes can be interferometrically combined; again the vacuum environment with constant refractive index of unity throughout, permits combination without phase delay across the entire spectral range. But thermal radiation from optical components and stray radiation from the lunar environment, just outside the light path, tend to lessen that advantage, except in narrow-spectral-band spatial interferometry, in which only the radiation in individual spectral lines is mapped, and broad-band thermal emission can be effectively filtered out. On the Moon's night side, and in polar craters on the Moon, radiative cooling should permit the attainment of high sensitivity with large telescopes. Just as the proposed Edison spacecraft primary mirror is expected to reach temperatures around 40 K, so also large lunar primary mirrors might be expected to reach temperatures in that range, making the zodiacal glow the main source of noise at wavelengths shortward of 25 micrometers. The slow rota tion of the Moon, and the lack of vibrations from natural sources such as winds, should provide advantages in guiding on specific astronomical sources. To learn as much as possible about the difficulties of remote observations in a hostile environment, Antarctic observatories should be used as test beds for the rigors of lunar observations. The strenuous requirements for successful astronomical observations from the South Pole are similar to those

  18. Infrared astronomy from the Moon

    NASA Astrophysics Data System (ADS)

    Harwit, Martin

    1994-06-01

    The purpose of this paper is to exhibit the advantages and limitations to infrared astronomical observations form the moon. The most obvious apparent advantage is the lack of a lunar atmosphere; radiation arriving from the universe is neither extinguished nor refracted as it approaches the lunar surface. However, the Earth's atmosphere's protection against cosmic rays is also lost, and infrared detectors are highly sensitive to irradiation by energetic particles. A second apparent advantage is the relative ease with which beams from an array of telescopes can be interferometrically combined; again the vacuum environment with constant refractive index of unity throughout, permits combination without phase delay across the entire spectral range. But thermal radiation from optical components and stray radiation from the lunar environment, just outside the light path, tend to lessen that advantage, except in narrow-spectral-band spatial interferometry, in which only the radiation in individual spectral lines is mapped, and broad-band thermal emission can be effectively filtered out. On the Moon's night side, and in polar craters on the Moon, radiative cooling should permit the attainment of high sensitivity with large telescopes. Just as the proposed Edison spacecraft primary mirror is expected to reach temperatures around 40 K, so also large lunar primary mirrors might be expected to reach temperatures in that range, making the zodiacal glow the main source of noise at wavelengths shortward of 25 micrometers. The slow rota tion of the Moon, and the lack of vibrations from natural sources such as winds, should provide advantages in guiding on specific astronomical sources. To learn as much as possible about the difficulties of remote observations in a hostile environment, Antarctic observatories should be used as test beds for the rigors of lunar observations. The strenuous requirements for successful astronomical observations from the South Pole are similar to those

  19. Compression of interferometric radio-astronomical data

    NASA Astrophysics Data System (ADS)

    Offringa, A. R.

    2016-11-01

    Context. The volume of radio-astronomical data is a considerable burden in the processing and storing of radio observations that have high time and frequency resolutions and large bandwidths. For future telescopes such as the Square Kilometre Array (SKA), the data volume will be even larger. Aims: Lossy compression of interferometric radio-astronomical data is considered to reduce the volume of visibility data and to speed up processing. Methods: A new compression technique named "Dysco" is introduced that consists of two steps: a normalization step, in which grouped visibilities are normalized to have a similar distribution; and a quantization and encoding step, which rounds values to a given quantization scheme using a dithering scheme. Several non-linear quantization schemes are tested and combined with different methods for normalizing the data. Four data sets with observations from the LOFAR and MWA telescopes are processed with different processing strategies and different combinations of normalization and quantization. The effects of compression are measured in image plane. Results: The noise added by the lossy compression technique acts similarly to normal system noise. The accuracy of Dysco is depending on the signal-to-noise ratio (S/N) of the data: noisy data can be compressed with a smaller loss of image quality. Data with typical correlator time and frequency resolutions can be compressed by a factor of 6.4 for LOFAR and 5.3 for MWA observations with less than 1% added system noise. An implementation of the compression technique is released that provides a Casacore storage manager and allows transparent encoding and decoding. Encoding and decoding is faster than the read/write speed of typical disks. Conclusions: The technique can be used for LOFAR and MWA to reduce the archival space requirements for storing observed data. Data from SKA-low will likely be compressible by the same amount as LOFAR. The same technique can be used to compress data from

  20. 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.

  1. Superresolved spatially multiplexed interferometric microscopy.

    PubMed

    Picazo-Bueno, José Ángel; Zalevsky, Zeev; García, Javier; Micó, Vicente

    2017-03-01

    Superresolution capability by angular and time multiplexing is implemented onto a regular microscope. The technique, named superresolved spatially multiplexed interferometric microscopy (S2MIM), follows our previously reported SMIM technique [Opt. Express22, 14929 (2014)OPEXFF1094-408710.1364/OE.22.014929, J. Biomed. Opt.21, 106007 (2016)JBOPFO1083-366810.1117/1.JBO.21.10.106007] improved with superresolved imaging. All together, S2MIM updates a commercially available non-holographic microscope into a superresolved holographic one. Validation is presented for an Olympus BX-60 upright microscope with resolution test targets.

  2. Interferometric optical vortex array generator

    SciTech Connect

    Vyas, Sunil; Senthilkumaran, P

    2007-05-20

    Two new interferometric configurations for optical vortex array generation are presented.These interferometers are different from the conventional interferometers in that they are capable of producing a large number of isolated zeros of intensity, and all of them contain optical vortices. Simulation and theory for optical vortex array generation using three-plane-wave interference is presented. The vortex dipole array produced this way is noninteracting, as there are no attraction or repulsion forces between them, leading to annihilation or creation of vortex pairs.

  3. Improved Interferometric Photorefractive Optical Processor

    NASA Technical Reports Server (NTRS)

    Cheng, Li-Jen; Liu, Tsuen-Hsi

    1991-01-01

    Processing speed increased substantially. Improved optical interferometric image-processing scheme based on four-wave mixing via photorefractive effect in GaAs or InP. Gives rise to index-of-refraction gratings acting as phase-conjugate mirrors: interactions among four input beams generate wave-front-reversed replicas of two of these beams. Each phase-conjugate beam travels precisely back along path of corresponding input beam, regardless of angle of incidence. Any distortions introduced into input beam during forward propagation removed from phase-conjugate beam during backward propagation.

  4. 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.

  5. 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.

  6. VLTI First Fringes with Two Auxiliary Telescopes at Paranal

    NASA Astrophysics Data System (ADS)

    2005-03-01

    interferometric installation of this size and crucial for its exceptional performance. The ATs may be placed at 30 different positions and thus be combined in a very large number of ways. If the 8.2-m VLT Unit Telescopes are also taken into account, no less than 254 independent pairings of two telescopes ("baselines"), different in length and/or orientation, are available. Moreover, while the largest possible distance between two 8.2-m telescopes (ANTU and YEPUN) is about 130 metres, the maximal distance between two ATs may reach 200 metres. As the achievable image sharpness increases with telescope separation, interferometric observations with the ATs positioned at the extreme positions will therefore yield sharper images than is possible by combining light from the large telescopes alone. All of this will enable the VLTI to obtain exceedingly detailed (sharp) and very complete images of celestial objects - ultimately with a resolution that corresponds to detecting an astronaut on the Moon. Auxiliary Telescope no. 1 (AT1) was installed on the observatory's platform in January 2004. Now, one year later, the second of the four to be delivered, has been integrated into the VLTI. The installation period lasted two months and ended around midnight during the night of February 2-3, 2005. With extensive experience from the installation of AT1, the team of engineers and astronomers were able to combine the light from the two Auxiliary Telescopes in a very short time. In fact, following the necessary preparations, it took them only five minutes to adjust this extremely complex optical system and successfully capture the "First Fringes" with the VINCI test instrument! The star which was observed is named HD62082 and is just at the limit of what can be observed with the unaided eye (its visual magnitude is 6.2). The fringes were as clear as ever, and the VLTI control system kept them stable for more than one hour. Four nights later this exercise was repeated successfully with the mid-infrared

  7. An overview of interferometric metrology and NDT techniques and applications for the aerospace industry

    NASA Astrophysics Data System (ADS)

    Georges, Marc P.; Thizy, Cédric; Languy, Fabian; Vandenrijt, Jean-François

    2016-08-01

    We review some full-field interferometric techniques which have been successfully applied in different applications related to the aerospace industry. The first part of the paper concerns the long-wave infrared (LWIR) digital holographic interferometry which allows the measurement large displacements that occur when space structures undergo large temperature excursions. A second part of the paper concerns different developments in interferometric nondestructive testing (NDT) techniques intended to improve their usability in aerospace industrial environments. Among others, we discuss LWIR speckle interferometry for simultaneous deformation and temperature variation measurements and new post-processing techniques applied to shearography for an easier detection of flaws in composite structures.

  8. 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.

  9. Phase closure retrieval in an infrared-to-visible upconversion interferometer for high resolution astronomical imaging.

    PubMed

    Ceus, Damien; Tonello, Alessandro; Grossard, Ludovic; Delage, Laurent; Reynaud, François; Herrmann, Harald; Sohler, Wolfgang

    2011-04-25

    This paper demonstrates the use of a nonlinear upconversion process to observe an infrared source through a telescope array detecting the interferometric signal in the visible domain. We experimentally demonstrate the possibility to retrieve information on the phase of the object spectrum of an infrared source by using a three-arm upconversion interferometer. We focus our study on the acquisition of phase information of the complex visibility by means of the phase closure technique. In our experimental demonstration, a laboratory binary star with an adjustable photometric ratio is used as a test source. A real time comparison between a standard three-arm interferometer and our new concept using upconversion by sum-frequency generation demonstrates the preservation of phase information which is essential for image reconstruction.

  10. LISA Telescope Spacer Design Issues

    NASA Technical Reports Server (NTRS)

    Livas, Jeff; Arsenovic, P.; Catelluci, K.; Generie, J.; Howard, J.; Stebbins, Howard R.; Preston, A.; Sanjuan, J.; Williams, L.; Mueller, G.

    2010-01-01

    The LISA mission observes gravitational waves by measuring the separations between freely floating proof masses located 5 million kilometers apart with an accuracy of - 10 picometers. The separations are measured interferometrically. The telescope is an afocal Cassegrain style design with a magnification of 80x. The entrance pupil has a 40 cm diameter and will either be centered on-axis or de-centered off-axis to avoid obscurations. Its two main purposes are to transform the small diameter beam used on the optical bench to a diffraction limited collimated beam to efficiently transfer the metrology laser between spacecraft, and to receive the incoming light from the far spacecraft. It transmits and receives simultaneously. The basic optical design and requirements are well understood for a conventional telescope design for imaging applications, but the LISA design is complicated by the additional requirement that the total optical path through the telescope must remain stable at the picometer level over the measurement band during the mission to meet the measurement accuracy. We describe the mechanical requirements for the telescope and the preliminary work that has been done to understand the materials and mechanical issues associated with the design of a passive metering structure to support the telescope and to maintain the spacing between the primary and secondary mirrors in the LISA on-orbit environment. This includes the requirements flowdown from the science goals, thermal modeling of the spacecraft and telescope to determine the expected temperature distribution, layout options for the telescope including an on- and off-axis design. Plans for fabrication and testing will be outlined.

  11. An interferometric study of the Fomalhaut inner debris disk. III. Detailed models of the exozodiacal disk and its origin

    NASA Astrophysics Data System (ADS)

    Lebreton, J.; van Lieshout, R.; Augereau, J.-C.; Absil, O.; Mennesson, B.; Kama, M.; Dominik, C.; Bonsor, A.; Vandeportal, J.; Beust, H.; Defrère, D.; Ertel, S.; Faramaz, V.; Hinz, P.; Kral, Q.; Lagrange, A.-M.; Liu, W.; Thébault, P.

    2013-07-01

    Context. Debris disks are thought to be extrasolar analogs to the solar system planetesimal belts. The star Fomalhaut harbors a cold debris belt at 140 AU comparable to the Edgeworth-Kuiper belt, as well as evidence of a warm dust component, unresolved by single-dish telescopes, which is suspected of being a bright analog to the solar system's zodiacal dust. Aims: Interferometric observations obtained with the VLTI/VINCI instrument and the Keck Interferometer Nuller have identified near- and mid-infrared excesses attributed respectively to hot and warm exozodiacal dust residing in the inner few AU of the Fomalhaut environment. We aim to characterize the properties of this double inner dust belt and to unveil its origin. Methods: We performed parametric modeling of the exozodiacal disk ("exozodi") using the GRaTeR radiative transfer code to reproduce the interferometric data, complemented by mid- to far-infrared photometric measurements from Spitzer and Herschel. A detailed treatment of sublimation temperatures was introduced to explore the hot population at the size-dependent sublimation rim. We then used an analytical approach to successively testing several source mechanisms for the dust and suspected parent bodies. Results: A good fit to the multiwavelength data is found by two distinct dust populations: (1) a population of very small (0.01 to 0.5 μm), hence unbound, hot dust grains confined in a narrow region (~0.1-0.3 AU) at the sublimation rim of carbonaceous material; (2) a population of bound grains at ~2 AU that is protected from sublimation and has a higher mass despite its fainter flux level. We propose that the hot dust is produced by the release of small carbon grains following the disruption of dust aggregates that originate in the warm component. A mechanism, such as gas braking, is required to further confine the small grains for a long enough time. In situ dust production could hardly be ensured for the age of the star, so we conclude that the

  12. Multi-color interferometric observations of Mira stars

    NASA Technical Reports Server (NTRS)

    Mennesson, B.; Creech-Eakman, M.; Thompson, B. B.; Foresto, V. Coude du; Merand, A.; Ridgway, S.; Perrin, G.

    2002-01-01

    Interferometric observations in the atmospheric windows of the near infrared (1 to 4 microns) can be efficiently used to probe the chemical composition of Miras atmosphere and provide direct measurements of extended gas layers around these stars. This is illustrated by recent Miras observations carried out with the FLUOR instrument of the IOTA interferometer (Mennesson et al. 2002, and Perrin et al. proceedings of this conference) and with the PTI test-bed (Thompson 2002, Thompson et al. 2002). These visibility measurements show evidence for continuum emission from very extended ( 2-3 stellar radii) semi-transparent gaseous atmospheric layers, and large apparent diameter changes with pulsation phase. Interestingly these observations are consistent with the extended molecular gas layers (H20, CO ...) already inferred around some of these objects from IS0 and high resolution ground-based FTS infrared spectra.

  13. VLT interferometer upgrade for the 2nd generation of interferometric instruments

    NASA Astrophysics Data System (ADS)

    Gonté, Frederic; Woillez, Julien; Schuhler, Nicolas; Egner, Sebastian; Merand, Antoine; Abad, José Antonio; Abadie, Sergio; Abuter, Roberto; Acuña, Margarita; Allouche, Fatmé; Alonso, Jaime; Andolfalto, Luigi; Antonelli, Pierre; Avila, Gerardo; Barriga, Pablo José; Beltran, Juan; Berger, Jean-Philippe; Bolados, Carlos; Bonnet, Henri; Bourget, Pierre; Brast, Roland; Bristow, Paul; Caniguante, Luis; Castillo, Roberto; Conzelmann, Ralf; Cortes, Angela; Delplancke, Françoise; Del Valle, Diego; Derie, Frederic; Diaz, Alvaro; Donoso, Reinaldo; Dorn, Reinhold; Duhoux, Philippe; Dupuy, Christophe; Eisenhauer, Frank; Elao, Christian; Fuenteseca, Eloy; Fernandez, Ruben; Gaytan, Daniel; Glindemann, Andreas; Gonzales, Jaime; Guieu, Sylvain; Guisard, Stephane; Haguenauer, Pierre; Haimerl, Andreas; Heinz, Volker; Henriquez, Juan Pablo; van der Heyden, P.; Hubin, Norbert; Huerta, Rodrigo; Jochum, Lieselotte; Leiva, Alfredo; Lévêque, Samuel; Lizon, Jean-Louis; Luco, Fernando; Mardones, Pedro; Mellado, Angel; Osorio, Juan; Ott, Jürgen; Pallanca, Laurent; Pavez, Marcus; Pasquini, Luca; Percheron, Isabelle; Pirard, Jean-Francois; Than Phan, Duc; Pineda, Juan Carlos; Pino, Andres; Poupar, Sebastien; Ramírez, Andres; Reinero, Claudio; Riquelme, Miguel; Romero, Juan; Rivinius, Thomas; Rojas, Chester; Rozas, Felix; Salgado, Fernando; Scheithauer, Silvia; Schmid, Christian; Schöller, Markus; Siclari, Waldo; Stephan, Christian; Tamblay, Richard; Tapia, Mario; Tristram, Konrad; Valdes, Guillermo; de Wit, Willem-Jan; Wright, Andrew; Zins, Gerard

    2016-08-01

    ESO is undertaking a large upgrade of the infrastructure on Cerro Paranal in order to integrate the 2nd generation of interferometric instruments Gravity and MATISSE, and increase its performance. This upgrade started mid 2014 with the construction of a service station for the Auxiliary Telescopes and will end with the implementation of the adaptive optics system for the Auxiliary telescope (NAOMI) in 2018. This upgrade has an impact on the infrastructure of the VLTI, as well as its sub-systems and scientific instruments.

  14. Far infrared supplement: Catalog of infrared observations

    NASA Astrophysics Data System (ADS)

    Gezari, Daniel Y.; Schmitz, Marion; Mead, Jaylee M.

    1982-10-01

    The development of a new generation of orbital, airborne and ground-based infrared astronomical observatory facilities, including the infrared astronomical satellite (IRAS), the cosmic background explorer (COBE), the NASA Kuiper airborne observatory, and the NASA infrared telescope facility, intensified the need for a comprehensive, machine-readable data base and catalog of current infrared astronomical observations. The Infrared Astronomical Data Base and its principal data product, this catalog, comprise a machine-readable library of infrared (1 micrometer to 1000 micrometers) astronomical observations published in the scientific literature since 1965.

  15. Far infrared supplement: Catalog of infrared observations

    NASA Technical Reports Server (NTRS)

    Gezari, D. Y.; Schmitz, M.; Mead, J. M.

    1982-01-01

    The development of a new generation of orbital, airborne and ground-based infrared astronomical observatory facilities, including the infrared astronomical satellite (IRAS), the cosmic background explorer (COBE), the NASA Kuiper airborne observatory, and the NASA infrared telescope facility, intensified the need for a comprehensive, machine-readable data base and catalog of current infrared astronomical observations. The Infrared Astronomical Data Base and its principal data product, this catalog, comprise a machine-readable library of infrared (1 micrometer to 1000 micrometers) astronomical observations published in the scientific literature since 1965.

  16. DETECTION OF FAST TRANSIENTS WITH RADIO INTERFEROMETRIC ARRAYS

    SciTech Connect

    Bhat, N. D. R.; Chengalur, J. N.; Gupta, Y.; Prasad, J.; Roy, J.; Kudale, S. S.; Cox, P. J.; Bailes, M.; Burke-Spolaor, S.; Van Straten, W.

    2013-05-01

    Next-generation radio arrays, including the Square Kilometre Array (SKA) and its pathfinders, will open up new avenues for exciting transient science at radio wavelengths. Their innovative designs, comprising a large number of small elements, pose several challenges in digital processing and optimal observing strategies. The Giant Metre-wave Radio Telescope (GMRT) presents an excellent test-bed for developing and validating suitable observing modes and strategies for transient experiments with future arrays. Here we describe the first phase of the ongoing development of a transient detection system for GMRT that is planned to eventually function in a commensal mode with other observing programs. It capitalizes on the GMRT's interferometric and sub-array capabilities, and the versatility of a new software backend. We outline considerations in the plan and design of transient exploration programs with interferometric arrays, and describe a pilot survey that was undertaken to aid in the development of algorithms and associated analysis software. This survey was conducted at 325 and 610 MHz, and covered 360 deg{sup 2} of the sky with short dwell times. It provides large volumes of real data that can be used to test the efficacies of various algorithms and observing strategies applicable for transient detection. We present examples that illustrate the methodologies of detecting short-duration transients, including the use of sub-arrays for higher resilience to spurious events of terrestrial origin, localization of candidate events via imaging, and the use of a phased array for improved signal detection and confirmation. In addition to demonstrating applications of interferometric arrays for fast transient exploration, our efforts mark important steps in the roadmap toward SKA-era science.

  17. Detection of Fast Transients with Radio Interferometric Arrays

    NASA Astrophysics Data System (ADS)

    Bhat, N. D. R.; Chengalur, J. N.; Cox, P. J.; Gupta, Y.; Prasad, J.; Roy, J.; Bailes, M.; Burke-Spolaor, S.; Kudale, S. S.; van Straten, W.

    2013-05-01

    Next-generation radio arrays, including the Square Kilometre Array (SKA) and its pathfinders, will open up new avenues for exciting transient science at radio wavelengths. Their innovative designs, comprising a large number of small elements, pose several challenges in digital processing and optimal observing strategies. The Giant Metre-wave Radio Telescope (GMRT) presents an excellent test-bed for developing and validating suitable observing modes and strategies for transient experiments with future arrays. Here we describe the first phase of the ongoing development of a transient detection system for GMRT that is planned to eventually function in a commensal mode with other observing programs. It capitalizes on the GMRT's interferometric and sub-array capabilities, and the versatility of a new software backend. We outline considerations in the plan and design of transient exploration programs with interferometric arrays, and describe a pilot survey that was undertaken to aid in the development of algorithms and associated analysis software. This survey was conducted at 325 and 610 MHz, and covered 360 deg2 of the sky with short dwell times. It provides large volumes of real data that can be used to test the efficacies of various algorithms and observing strategies applicable for transient detection. We present examples that illustrate the methodologies of detecting short-duration transients, including the use of sub-arrays for higher resilience to spurious events of terrestrial origin, localization of candidate events via imaging, and the use of a phased array for improved signal detection and confirmation. In addition to demonstrating applications of interferometric arrays for fast transient exploration, our efforts mark important steps in the roadmap toward SKA-era science.

  18. Interferometric biochemical and chemical sensors

    NASA Astrophysics Data System (ADS)

    Gauglitz, Guenter; Brecht, Andreas; Kraus, Gerolf

    1995-09-01

    Interferometric principles have gained wide acceptance in the field of chemical and biochemical sensing. Reflectometric interference spectrometry sensors using white light multiple reflections at thin layers, structures of polymers, or monolayers of biochemicals are discussed in a survey. These are compared to other techniques, especially methods using surface plasmon resonance and grating couplers. Applications in the area of environmental monitoring in public safety are given, demonstrating the results for halogenated hydrocarbons in air and water as well as pesticides in ground water. Calibration curves, limits of decision, of detection, and of determination are specified and discussed with respect to EU limits. The application of multivariate data analysis is considered including artificial neuronal networks for multisensor systems and referencing in the case of gas sensors.

  19. Multifocal interferometric synthetic aperture microscopy

    PubMed Central

    Xu, Yang; Chng, Xiong Kai Benjamin; Adie, Steven G.; Boppart, Stephen A.; Scott Carney, P.

    2014-01-01

    There is an inherent trade-off between transverse resolution and depth of field (DOF) in optical coherence tomography (OCT) which becomes a limiting factor for certain applications. Multifocal OCT and interferometric synthetic aperture microscopy (ISAM) each provide a distinct solution to the trade-off through modification to the experiment or via post-processing, respectively. In this paper, we have solved the inverse problem of multifocal OCT and present a general algorithm for combining multiple ISAM datasets. Multifocal ISAM (MISAM) uses a regularized combination of the resampled datasets to bring advantages of both multifocal OCT and ISAM to achieve optimal transverse resolution, extended effective DOF and improved signal-to-noise ratio. We present theory, simulation and experimental results. PMID:24977909

  20. 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)

  1. UBVR and Hubble Space Telescope Mid-Ultraviolet and Near-Infrared Surface Photometry and Radial Color Gradients of Late-Type, Irregular, and Peculiar Galaxies

    NASA Astrophysics Data System (ADS)

    Taylor, Violet A.; Jansen, Rolf A.; Windhorst, Rogier A.; Odewahn, Stephen C.; Hibbard, John E.

    2005-09-01

    We introduce a data set of 142 mostly late-type spiral, irregular, and peculiar (interacting or merging) nearby galaxies observed in UBVR at the Vatican Advanced Technology Telescope (VATT), and we present an analysis of their radial color gradients. We confirm that nearby elliptical and early- to mid-type spiral galaxies show either no or only small color gradients, becoming slightly bluer with radius. In contrast, we find that late-type spiral, irregular, peculiar, and merging galaxies become on average redder with increasing distance from the center. The scatter in radial color gradient trends increases toward later Hubble type. As a preliminary analysis of a larger data set obtained with the Hubble Space Telescope (HST), we also analyze the color gradients of six nearby galaxies observed with NICMOS in the near-IR (H) and with WFPC2 in the mid-UV (F300W) and red (F814W). We discuss the possible implications of these results on galaxy formation and compare our nearby galaxy color gradients to those at high redshift. We present examples of images and UBVR radial surface brightness and color profiles, as well as of the tables of measurements; the full atlas and tables are published in the electronic edition only. 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 8645, 9124, and 9824.

  2. 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

  3. Interferometric test method for testing convex aspheric mirror surfaces

    NASA Astrophysics Data System (ADS)

    McKechnie, T. Stewart

    2010-07-01

    An interferometric null Test Method is described for testing convex aspheric surfaces, such as found in secondary mirrors of Cassegrain telescopes or variations thereof such as Mersenne and Ritchey-Chrétien. A family of test designs is described covering a wide range of mirror diameters, radii of curvature, and aspheric shapes as described by conic constants and/or polynomials. The Test Method has been used successfully for testing the convex hyperboloid surface of the 244-mm diameter secondary mirror of the NASA 3-meter IRTF telescope. The Test Method is currently being used to test the 120-mm diameter, convex paraboloid secondary mirrors of the Magdalena Ridge Observatory Interferometer (MROI). Test designs exist on paper for both Keck secondary mirrors (0.53-m and 1.4-m diameter), the HST secondary (0.3-meter diameter), and secondary mirrors of some of the extremely large telescopes of the future, such as the TMT secondary (3.2-m diameter). In typical test embodiments, the simplicity of the Test enables rapid implementation at a fraction of the cost of comparable Hindle-Sphere or Hindle-Simpson tests.

  4. Radio-interferometric Neutrino Reconstruction for the Askaryan Radio Array

    NASA Astrophysics Data System (ADS)

    Lu, Ming-Yuan

    2017-03-01

    The Askaryan Radio Array (ARA) is a neutrino telescope array under phased deployment near the South Pole. The array aims to discover and determine the ultra-high energy neutrino flux via detection of the Askaryan signal from neutrino-induced showers. This novel detection channel makes ARA the most cost-effective neutrino observatory in probing the neutrino flux from 1017eV - 1019eV. This contribution will discuss an interferometric vertex reconstruction technique developed for ARA, taking into account the curved paths traveled by EM radiation in inhomogeneous ice. Preliminary results on the directional reconstruction of an in situ calibration pulser as well as simulated neutrino vertices will be presented.

  5. Feasibility of coupling Euro50 interferometrically to a Carlina hypertelescope

    NASA Astrophysics Data System (ADS)

    Labeyrie, Antoine

    2004-07-01

    The interferometric coupling of an ELT with a large multi-aperture imaging interferometer can open new areas of science on compact objects. Numerical simulations indeed show that the combined image retains respectively the high luminosity and the high angular resolution of both instruments. The Canarian site envisaged for the Euro-50 is adjacent to the large Caldera de Taburiente crater, a favorable site for an optical and dilute form of the Arecibo radio-telescope. Our preliminary study indicates that the effective aperture size can exceed 1600 m if a balloon or kite is used to carry the focal optics, also receiving a coude beam from the Euro-50 if coupled. In spite of inherent limitations regarding field size and crowding, the 50 micro-arcsecond resolution thus achievable in visible snapshot images is of interest for stellar physics, active galactic nuclei and deep cosmological imaging of remote galaxies.

  6. Integrated circuit tester using interferometric imaging

    SciTech Connect

    Donaldson, W.R.; Michaels, E.M.R.; Akowuah, K.

    1997-04-01

    An interferometric imaging technique can provide time-resolved diagnostics of semiconductor integrated circuits. The semiconductor device is placed in one arm of an interferometer and illuminated with a picosecond pulse from a sub-bandgap infrared laser. As the laser passes through the semiconductor, it samples local variations in the index of refraction. These variations are caused by a number of physical phenomena including dopants in the material such as those used to form device structures, heating due to the flow of electrical currents, and changes in carrier concentration due to injection. These variations have both static and dynamic components. The dynamic components are associated with the normal device operation and are the most interesting. To separate the components, the device is first imaged in a quiescent state, and then a second image is taken after the device enters a known voltage state. Differences between the two images determine where the local index of refraction has changed and by how much. A third image taken with the reference arm of the interferometer blocked, allows device structures to be associated with particular changes in the index of refraction. Activation of the voltage state is synchronized with the pulsed illumination source, and the time delay between the application of the voltage and the laser probe pulse allows us to take a series of images that map the time evolution of the interferogram. This technique offers an exciting new diagnostic for semiconductor integrated circuits. The technique is noninvasive and compatible with high-speed operation of integrated circuits. The picosecond resolution enables us to either characterize specific logic states or watch an individual device turn on. This imaging technique is sensitive to all of the index of refraction changes that can be associated with IC`s. These include heating due to current flowing through narrow wires and charge injection into the depletion region of a transistor.

  7. Science cases in the integrated modeling of Chinese Giant Solar Telescope

    NASA Astrophysics Data System (ADS)

    Liu, Zhong; Ji, Haisheng; Jin, Zhenyu; Lin, Jun; Deng, Yuanyong

    2016-07-01

    Science goals of telescopes are the fundament data of integrated modeling of astronomical telescopes. The differences between science goals are sources of telescope's diversities. Solar telescopes are a very special type in astronomical telescopes. Chinese Giant Solar Telescope1 (CGST) is currently designed to be an 8-meter Ring Interferometric Telescope (RIT). Even compare with the other solar telescopes, CGST is also an unusual telescope due to its ring aperture and distinctive science goals. As the initial data of integrated modeling of CGST, the main science cases determine the basic structure of the telescope as well as its working mode. This paper will discuss the importance of the primary science case in integrated modeling of CGST.

  8. Tangential Velocity Measurement Using Interferometric MTI Radar

    SciTech Connect

    DOERRY, ARMIN W.; MILESHOSKY, BRIAN P.; BICKEL, DOUGLAS L.

    2002-11-01

    An Interferometric Moving Target Indicator radar can be used to measure the tangential velocity component of a moving target. Multiple baselines, along with the conventional radial velocity measurement, allow estimating the true 3-D velocity vector of a target.

  9. SINS/zC-SINF Survey of z ˜ 2 Galaxy Kinematics: Rest-frame Morphology, Structure, and Colors from Near-infrared Hubble Space Telescope Imaging

    NASA Astrophysics Data System (ADS)

    Tacchella, S.; Lang, P.; Carollo, C. M.; Förster Schreiber, N. M.; Renzini, A.; Shapley, A. E.; Wuyts, S.; Cresci, G.; Genzel, R.; Lilly, S. J.; Mancini, C.; Newman, S. F.; Tacconi, L. J.; Zamorani, G.; Davies, R. I.; Kurk, J.; Pozzetti, L.

    2015-04-01

    We present the analysis of Hubble Space Telescope (HST) J- and H-band imaging for 29 galaxies on the star-forming main sequence at z ˜ 2, which have adaptive optics Very Large Telescope SINFONI integral field spectroscopy from our SINS/zC-SINF program. The SINFONI Hα data resolve the ongoing star formation and the ionized gas kinematics on scales of 1-2 kpc; the near-IR images trace the galaxies’ rest-frame optical morphologies and distributions of stellar mass in old stellar populations at a similar resolution. The global light profiles of most galaxies show disk-like properties well described by a single Sérsic profile with n˜ 1, with only ˜ 15% requiring a high n\\gt 3 Sérsic index, all more massive than {{10}10} {{M}⊙ }. In bulge+disk fits, about 40% of galaxies have a measurable bulge component in the light profiles, with ˜ 15% showing a substantial bulge-to-total ratio (B/T) B/T≳ 0.3. This is a lower limit to the frequency of z ˜ 2 massive galaxies with a developed bulge component in stellar mass because it could be hidden by dust and/or outshined by a thick actively star-forming disk component. The galaxies’ rest-optical half-light radii range between 1 and 7 kpc, with a median of 2.1 kpc, and lie slightly above the size-mass relation at these epochs reported in the literature. This is attributed to differences in sample selection and definitions of size and/or mass measurements. The {{(u-g)}rest} color gradient and scatter within individual z ˜ 2 massive galaxies with ≳ {{10}11} {{M}⊙ } are as high as in z = 0 low-mass, late-type galaxies and are consistent with the high star formation rates of massive z ˜ 2 galaxies being sustained at large galactocentric distances. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute.

  10. Integration of an interferometric IR absorber into an epoxy membrane based CO2 detector

    NASA Astrophysics Data System (ADS)

    Ashraf, S.; Mattsson, C. G.; Thungström, G.; Rödjegård, H.

    2014-05-01

    Measurements of carbon dioxide levels in the environment are commonly performed by using non-dispersive infrared technology (NDIR). Thermopile detectors are often used in NDIR systems because of their non-cooling advantages. The infrared absorber has a major influence on the detector responsivity. In this paper, the fabrication of a SU-8 epoxy membrane based Al/Bi thermopile detector and the integration of an interferometric infrared absorber structure of wavelength around 4 μm into the detector is reported. The membrane of thermopile detector has been utilized as a dielectric medium in an interferometric absorption structure. By doing so, a reduction in both thermal conductance and capacitance is achieved. In the fabrication of the thermopile, metal evaporation and lift off process had been used for the deposition of serially interconnected Al/Bi thermocouples. Serial resistance of fabricated thermopile was measured as 220 kΩ. The response of fabricated thermopile detector was measured using a visible to infrared source of radiation flux 3.23 mW mm-2. The radiation incident on the detector was limited using a band pass filter of wavelength 4.26 μm in front of the detector. A responsivity of 27.86 V mm2 W-1 at room temperature was achieved using this setup. The fabricated detector was compared to a reference detector with a broad band absorber. From the comparison it was concluded that the integrated interferometric absorber is functioning correctly.

  11. A Interferometric Approach to Suppression of Scattered Radiant Energy

    NASA Astrophysics Data System (ADS)

    Thompson, Christopher John Campbell

    The concept of using an interferometric process to reduce scattered light in optical systems has been examined from a physical optics viewpoint. An experiment is described which illustrates the basic concepts of a particular scheme addressing the important case of a telescope viewing a distant point object whose image is degraded by scattering from dust on the primary lens. A basic conceptual scheme is described, utilizing a modified Twyman-Green interferometer, which introduces a (pi) phase shift and a focal power difference between the arms. The interferometer is inserted into the optical train of an elementary telescope to null the scattered energy while preserving the image intensity associated with the distant point object, thereby enhancing the signal -to-noise ratio. The effect of this interferometer on the image of a distant point object is examined in detail. Computer techniques were used to solve Lommel function based series representations of the diffraction integral, and generate the intensity distributions which are presented as a series of iso-intensity contour maps. The results indicate that a distant point object could be reimaged successfully. Further analytic evaluations reveal specific operating conditions for the interferometer that optimize the peak intensity at the focal plane. A wavefront model was used to derive the radially dependent intensity distribution at the focal plane from the single on-axis scattering point. To evaluate the effectiveness of the scatter-nulling interferometric technique, an analytic expression for the gain in signal-to-noise ratio was developed, utilizing elementary models of a reimaging systems with and without the inclusion of a nulling interferometer. Gains up to a factor of 10('8) were observed with the assumption of a reasonable set of system parameters and for the limited set of conditions employed. Results imply that the interferometric approach could be successful and effective under restricted conditions

  12. Characterization of the transmitted near-infrared wavefront error for the GRAVITY/VLTI Coudé Infrared Adaptive Optics System.

    PubMed

    Yang, Pengqian; Hippler, Stefan; Deen, Casey P; Brandner, Wolfgang; Clénet, Yann; Henning, Thomas; Huber, Armin; Kendrew, Sarah; Lenzen, Rainer; Pfuhl, Oliver; Zhu, Jianqiang

    2013-04-08

    The adaptive optics system for the second-generation VLT-interferometer (VLTI) instrument GRAVITY consists of a novel cryogenic near-infrared wavefront sensor to be installed at each of the four unit telescopes of the Very Large Telescope (VLT). Feeding the GRAVITY wavefront sensor with light in the 1.4 to 2.4 micrometer band, while suppressing laser light originating from the GRAVITY metrology system, custom-built optical components are required. In this paper, we present the development of a quantitative near-infrared point diffraction interferometric characterization technique, which allows measuring the transmitted wavefront error of the silicon entrance windows of the wavefront sensor cryostat. The technique can be readily applied to quantitative phase measurements in the near-infrared regime. Moreover, by employing a slightly off-axis optical setup, the proposed method can optimize the required spatial resolution and enable real time measurement capabilities. The feasibility of the proposed setup is demonstrated, followed by theoretical analysis and experimental results. Our experimental results show that the phase error repeatability in the nanometer regime can be achieved.

  13. ASTROCAM: An Offner Re-imaging 1024 x 1024 InSb Camera for Near-Infrared Astrometry on the USNO 1.55-m Telescope

    DTIC Science & Technology

    2003-01-01

    Kosakowskif, C. C. Dudleya and Kenneth Johnstoni aNaval Research Laboratory, Remote Sensing Division, Washington, DC, USA bU.S. Naval Observatory ...Flagstaff Station, PO Box 1149, Flagstaff, AZ, USA cMauna Kea Infrared, LLC, 159 Kalanikoa St, Hilo, HI USA dUniversity of Chicago Engineering Center...gApplied Designs, 3001 Specific Heights Rd, Honolulu, HI, USA hCAD Services, 1158 Mowai St, Kailua, HI, USA iU.S. Naval Observatory , 3450 Massachusetts

  14. Adaptive Nulling for Interferometric Detection of Planets

    NASA Technical Reports Server (NTRS)

    Lay, Oliver P.; Peters, Robert D.

    2010-01-01

    An adaptive-nulling method has been proposed to augment the nulling-optical- interferometry method of detection of Earth-like planets around distant stars. The method is intended to reduce the cost of building and aligning the highly precise optical components and assemblies needed for nulling. Typically, at the mid-infrared wavelengths used for detecting planets orbiting distant stars, a star is millions of times brighter than an Earth-sized planet. In order to directly detect the light from the planet, it is necessary to remove most of the light coming from the star. Nulling interferometry is one way to suppress the light from the star without appreciably suppressing the light from the planet. In nulling interferometry in its simplest form, one uses two nominally identical telescopes aimed in the same direction and separated laterally by a suitable distance. The light collected by the two telescopes is processed through optical trains and combined on a detector. The optical trains are designed such that the electric fields produced by an on-axis source (the star) are in anti-phase at the detector while the electric fields from the planet, which is slightly off-axis, combine in phase, so that the contrast ratio between the star and the planet is greatly decreased. If the electric fields from the star are exactly equal in amplitude and opposite in phase, then the star is effectively nulled out. Nulling is effective only if it is complete in the sense that it occurs simultaneously in both polarization states and at all wavelengths of interest. The need to ensure complete nulling translates to extremely tight demands upon the design and fabrication of the complex optical trains: The two telescopes must be highly symmetric, the reflectivities of the many mirrors in the telescopes and other optics must be carefully tailored, the optical coatings must be extremely uniform, sources of contamination must be minimized, optical surfaces must be nearly ideal, and alignments

  15. Radio and optical interferometric imaging

    NASA Technical Reports Server (NTRS)

    Cornwell, Tim J.

    1992-01-01

    Since diffraction-limited imaging with a single aperture yields angular resolution approx. lambda/D, the attainment of high angular resolution with single apertures requires the construction of correspondingly large monolithic apertures, the whole surface of which must be figured to much less than a wavelength. At the longer wavelengths, it is impossible to build a sufficiently large single aperture: for example, at lambda 21 cm, arcsec resolution requires an aperture of diameter approx. 50 km. At the shorter wavelengths, the atmosphere imposes a natural limit in resolution of about one arcsec. However, another route is possible; that is, using synthetic apertures to image the sky. Synthetic apertures are now in use in many fields, e.g., radio interferometry, radar imaging, and magnetic-resonance imaging. Radio-interferometric techniques developed in radio astronomy over the past 40 years are now being applied to optical and IR astronomical imaging by a number of groups. Furthermore, the problem of figuring synthetic apertures is considerably simpler, and can be implemented in a computer: new 'self-calibration' techniques allow imaging even in the presence of phase errors due to the atmosphere.

  16. Radio and optical interferometric imaging

    NASA Astrophysics Data System (ADS)

    Cornwell, Tim J.

    1992-11-01

    Since diffraction-limited imaging with a single aperture yields angular resolution approx. lambda/D, the attainment of high angular resolution with single apertures requires the construction of correspondingly large monolithic apertures, the whole surface of which must be figured to much less than a wavelength. At the longer wavelengths, it is impossible to build a sufficiently large single aperture: for example, at lambda 21 cm, arcsec resolution requires an aperture of diameter approx. 50 km. At the shorter wavelengths, the atmosphere imposes a natural limit in resolution of about one arcsec. However, another route is possible; that is, using synthetic apertures to image the sky. Synthetic apertures are now in use in many fields, e.g., radio interferometry, radar imaging, and magnetic-resonance imaging. Radio-interferometric techniques developed in radio astronomy over the past 40 years are now being applied to optical and IR astronomical imaging by a number of groups. Furthermore, the problem of figuring synthetic apertures is considerably simpler, and can be implemented in a computer: new 'self-calibration' techniques allow imaging even in the presence of phase errors due to the atmosphere.

  17. 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.

  18. 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…

  19. 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.

  20. LISA telescope spacer design investigations

    NASA Astrophysics Data System (ADS)

    Sanjuan, Josep; Mueller, Guido; Livas, Jeffrey; Preston, Alix; Arsenovic, Petar; Castellucci, Kevin; Generie, Joseph; Howard, Joseph; Stebbins, Robin

    The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave observa-tory with the goal of observing Gravitational Waves (GWs) from astronomical sources in a frequency range from 30 µHz to 0.1 Hz. The detection of GWs at such low frequency requires measurements of distances at the pico-meter level between bodies separated by 5 million kilo-meters. The LISA mission consists of three identical spacecraft (SC) separated by 5 × 106 km forming an equilateral triangle. Each SC contains two optical assemblies and two vacuum en-closures housing one proof mass (PM) in geodesic (free fall) motion each. The two assemblies on one SC are each pointing towards an identical assembly on each of the other two SC to form a non-equal arm interferometer. The measurement of the GW strain is done by measuring the change in the length of the optical path between the PMs of one arm relative to the other arms caused by the pass of a GW. An important element of the Interferometric Measurement System (IMS) is the telescope which, on one hand, gathers the light coming from the far SC (˜100 pW) and, on the other hand, expands and collimates the small outgoing beam ( 1 W) and sends it to the far SC. Due to the very demanding sensitivity requirements care must be taken in the design and validation of the telescope not to degrade the IMS performance. For instance, the diameter of the telescope sets the the shot noise of the IMS and depends critically on the diameter of the primary and the divergence angle of the outgoing beam. As the telescope is rather fast telescope, the divergence angle is a critical function of the overall separation between the primary and secondary. Any long term changes of the distance of more than a a few micro-meter would be detrimental to the LISA mission. Similarly challenging are the requirements on the in-band path-length noise for the telescope which has to be kept below 1 pm Hz-1/2 in the LISA band. Different configurations (on-axis/off axis

  1. Infrared astronomy takes center stage

    NASA Technical Reports Server (NTRS)

    Gillett, Frederick C.; Gatley, Ian; Hollenbach, David

    1991-01-01

    Characteristics of infrared astronomy, including the ability to detect cool matter, explore the hidden universe, reveal a wealth of spectral lines, and reach back to the beginning of time are outlined. Ground-based infrared observations such as observations in the thermal infrared region are discussed as well as observations utilizing infrared telescopes aboard NASA aircraft and orbiting telescopes. The Space Infrared Telescope Facility and the Stratospheric Observatory for Infrared Astronomy are described, and it is pointed out that infrared astronomers can penetrate obscuring dust to study stars and interstellar matter throughout the Milky Way galaxy. Application of various infrared instruments to the investigation of stars and planets is emphasized, and focus is placed on the discovery of clouds or disks of particles around mature stars and acquisition of high-resolution spectra of the gaseous and solid materials orbiting on the fringes of the solar system.

  2. Resolved Near-infrared Image of the Inner Cavity in the GM Aur Transitional Disk

    NASA Astrophysics Data System (ADS)

    Oh, Daehyeon; Hashimoto, Jun; Carson, Joseph C.; Janson, Markus; Kwon, Jungmi; Nakagawa, Takao; Mayama, Satoshi; Uyama, Taichi; Yang, Yi; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Abe, Lyu; Akiyama, Eiji; Brandner, Wolfgang; Brandt, Timothy D.; Currie, Thayne; Feldt, Markus; Goto, Miwa; Grady, Carol A.; Guyon, Olivier; Hayano, Yutaka; Hayashi, Masahiko; Hayashi, Saeko S.; Henning, Thomas; Hodapp, Klaus W.; Ishii, Miki; Iye, Masanori; Kandori, Ryo; Knapp, Gillian R.; Kuzuhara, Masayuki; Matsuo, Taro; Mcelwain, Michael W.; Miyama, Shoken; Morino, Jun-Ichi; Moro-Martin, Amaya; Nishimura, Tetsuo; Pyo, Tae-Soo; Serabyn, Eugene; Suenaga, Takuya; Suto, Hiroshi; Suzuki, Ryuji; Takahashi, Yasuhiro H.; Takato, Naruhisa; Terada, Hiroshi; Thalmann, Christian; Turner, Edwin L.; Watanabe, Makoto; Yamada, Toru; Takami, Hideki; Usuda, Tomonori; Tamura, Motohide

    2016-11-01

    We present high-contrast H-band polarized intensity (PI) images of the transitional disk around the young solar-like star GM Aur. The near-infrared direct imaging of the disk was derived by polarimetric differential imaging using the Subaru 8.2 m Telescope and HiCIAO. An angular resolution and an inner working angle of 0.″07 and r ˜ 0.″05, respectively, were obtained. We clearly resolved a large inner cavity, with a measured radius of 18 ± 2 au, which is smaller than that of a submillimeter interferometric image (28 au). This discrepancy in the cavity radii at near-infrared and submillimeter wavelengths may be caused by a 3-4 M Jup planet about 20 au away from the star, near the edge of the cavity. The presence of a near-infrared inner cavity is a strong constraint on hypotheses for inner cavity formation in a transitional disk. A dust filtration mechanism has been proposed to explain the large cavity in the submillimeter image, but our results suggest that this mechanism must be combined with an additional process. We found that the PI slope of the outer disk is significantly different from the intensity slope obtained from HST/NICMOS, and this difference may indicate the grain growth process in the disk. Based on ircs and hiciao data collected at subaru telescope, operated by the national astro-nomical observatory of japan.

  3. Studies of design parameters for interferometric methane sensors

    NASA Astrophysics Data System (ADS)

    Wykes, John S.; Willett, Martin J.; Croydon, W. F.

    1992-08-01

    Methane detectors based on the absorption of infrared radiation show some promise as the basis of sensitive and accurate industrial instrumentation. Comb filter methods that utilize the vibration-rotation structure of the methane spectrum in an optically efficient manner have recently aroused particular interest in this context. We describe a mathematical model to simulate the behavior of scanning interferometric comb filters in methane detection systems and discuss the use of the model to investigate optimum design parameters for such systems. The behavior of prototype methane detectors based on scanning Fabry-Perot and Mach Zehnder interferometers is briefly reported. Possible techniques for obtaining further improvements in the design of comb filters for methane detection are suggested.

  4. An overview of instrumentation for the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark

    2012-09-01

    An overview of instrumentation for the Large Binocular Telescope (LBT) is presented. Optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (27' x 27') mosaic CCD imagers at the prime focus, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam blue-red optimized long-slit spectrographs mounted at the left and right direct F/15 Gregorian foci incorporating multiple slit masks for multi-object spectroscopy over a 6' field and spectral resolutions of up to 2000. Infrared instrumentation includes the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCI), a modular near-infrared (0.9-2.5 μm) imager and spectrograph pair mounted at the left and right front bent F/15 Gregorian foci and designed for seeing-limited (FOV: 4' × 4') imaging, long-slit spectroscopy, and multiobject spectroscopy utilizing cooled slit masks and diffraction limited (FOV: 0'.5 × 0'.5) imaging and long-slit spectroscopy. Strategic instruments under development that can utilize the full 23-m baseline of the LBT include an interferometric cryogenic beam combiner with near-infrared and thermal-infrared instruments for Fizeau imaging and nulling interferometry (LBTI) and an optical bench near-infrared beam combiner utilizing multi-conjugate adaptive optics for high angular resolution and sensitivity (LINC-NIRVANA). LBTI is currently undergoing commissioning on the LBT and utilizing the installed adaptive secondary mirrors in both single- sided and two-sided beam combination modes. In addition, a fiber-fed bench spectrograph (PEPSI) capable of ultra high resolution spectroscopy and spectropolarimetry (R = 40,000-300,000) will be available as a principal investigator instrument. Over the past four years the LBC pair, LUCI1, and MODS1 have been commissioned and are now scheduled for routine partner science observations. The delivery of both LUCI2 and MODS2 is anticipated before the end of 2012. The

  5. Hundred metre virtual telescope captures unique detailed colour image

    NASA Astrophysics Data System (ADS)

    2009-02-01

    A team of French astronomers has captured one of the sharpest colour images ever made. They observed the star T Leporis, which appears, on the sky, as small as a two-storey house on the Moon [1]. The image was taken with ESO's Very Large Telescope Interferometer (VLTI), emulating a virtual telescope about 100 metres across and reveals a spherical molecular shell around an aged star. ESO PR Photo 06a/09 The star T Leporis as seen with VLTI ESO PR Photo 06b/09 The star T Leporis to scale ESO PR Photo 06c/09 A virtual 100-metre telescope ESO PR Photo 06d/09 The orbit of Theta1 Orionis C ESO PR Video 06a/09 Zoom-in onto T Leporis "This is one of the first images made using near-infrared interferometry," says lead author Jean-Baptiste Le Bouquin. Interferometry is a technique that combines the light from several telescopes, resulting in a vision as sharp as that of a giant telescope with a diameter equal to the largest separation between the telescopes used. Achieving this requires the VLTI system components to be positioned to an accuracy of a fraction of a micrometre over about 100 metres and maintained so throughout the observations -- a formidable technical challenge. When doing interferometry, astronomers must often content themselves with fringes, the characteristic pattern of dark and bright lines produced when two beams of light combine, from which they can model the physical properties of the object studied. But, if an object is observed on several runs with different combinations and configurations of telescopes, it is possible to put these results together to reconstruct an image of the object. This is what has now been done with ESO's VLTI, using the 1.8-metre Auxiliary Telescopes. "We were able to construct an amazing image, and reveal the onion-like structure of the atmosphere of a giant star at a late stage of its life for the first time," says Antoine Mérand, member of the team. "Numerical models and indirect data have allowed us to imagine the

  6. Optical aperture synthesis with electronically connected telescopes

    PubMed Central

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D.

    2015-01-01

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths. PMID:25880705

  7. Interferometric millimeter observations of water vapor on Mars

    NASA Astrophysics Data System (ADS)

    Fouchet, T.; Moreno, R.; Lellouch, E.; Montmessin, F.; Giuranna, M.; Formisano, V.

    2011-10-01

    We present interferometric mapping of the 225.9-GHz HDO and 203.4-GHz H2 18O lines on Mars obtained with the IRAM Plateau de Bure facility (PdBI). The observations were performed during martian year 28 (MY28), at Ls = 320.3° for the HDO line, and at Ls = 324.3° for the H2 18O line. The HDO line is detected at the eastern (morning) and western (evening) limbs of the northern hemisphere, corresponding to a water column density in the range 3-6 pr.-μm(Fig. 1). The H2 18O line is not detected, which is compatible with the column densities derived from the HDO line (Fig. 2). Quasi-simultaneous far infrared measurements obtained by the Planetary Fourier Spectrometer (PFS) onboard the Mars Express spacecraft confirm our PdBI results, yielding a 5±1 pr.-μm meridionally constant water column abundance (Fig 3). Such a low water abundance during the southern mid-autumn of MY28 does not correspond to the standard martian climatology as observed during the previous years. It was however already retrieved from near-infrared observations performed by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard the Mars Reconnaissance Orbiter spacecraft [Smith, M. D., Wolff, M. J., Clancy, R. T., Murchie, S. L. 2009. CRISM observations of water vapor and carbon monoxide. J. Geophys. Res. 114, doi:10.1029/2008JE003288]. Our observations thus confirm that the planet-encircling dust storm that occured during MY28 significantly affected the martian water cycle. Our observations also demonstrate the usefulness of interferometric submillimeter observations to survey the martian water cycle from groundbased facilities.

  8. European Extremely Large Telescope: progress report

    NASA Astrophysics Data System (ADS)

    Tamai, R.; Spyromilio, J.

    2014-07-01

    The European Extremely Large Telescope is a project of the European Southern Observatory to build and operate a 40-m class optical near-infrared telescope. The telescope design effort is largely concluded and construction contracts are being placed with industry and academic/research institutes for the various components. The siting of the telescope in Northern Chile close to the Paranal site allows for an integrated operation of the facility providing significant economies. The progress of the project in various areas is presented in this paper and references to other papers at this SPIE meeting are made.

  9. Design of optical systems for large space telescopes

    NASA Astrophysics Data System (ADS)

    Malamed, Evgeny R.; Sokolsky, M. N.

    1995-09-01

    On the basis of long-term experience of LOMO PLC in creating large optical systems for ground and space telescopes, with diameter of primary mirror from 1 to 6 meters, the following issues should be considered: principles of constructing optical systems for space telescopes and selecting their optimum design in respect of dimensions/mass and performance criteria; ensuring the fulfillment of image quality requirements in the process of manufacturing optical systems for controlling ground telescope elements in operating conditions; providing automatic adjustment of telescope secondary mirror, automatic focusing, interferometric control of image quality by means of stellar interferometer with radial shift and internal control with Gartman's test. Description of space telescope equipped with primary mirror of diameter 1.5 m, manufactured in LOMO PLC, is given.

  10. Infrared Astronomy with Arrays: The Next Generation; Sunset Village, Los Angeles, CA, Oct. 1993

    NASA Technical Reports Server (NTRS)

    Mclean, Ian S.

    1994-01-01

    Conference papers on infrared array techniques and methods for infrared astronomy are presented. Topics covered include the following: infrared telescopes; infrared spectrometers; spaceborne astronomy; astronomical observatories; infrared cameras; imaging techniques; sky surveys; infrared photography; infrared photometry; infrared spectroscopy; equipment specifications; data processing and analysis; control systems; cryogenic equipment; adaptive optics; image resolution; infrared detector materials; and focal plane arrays.

  11. Applications of interferometrically derived terrain slopes: Normalization of SAR backscatter and the interferometric correlation coefficient

    NASA Technical Reports Server (NTRS)

    Werner, Charles L.; Wegmueller, Urs; Small, David L.; Rosen, Paul A.

    1994-01-01

    Terrain slopes, which can be measured with Synthetic Aperture Radar (SAR) interferometry either from a height map or from the interferometric phase gradient, were used to calculate the local incidence angle and the correct pixel area. Both are required for correct thematic interpretation of SAR data. The interferometric correlation depends on the pixel area projected on a plane perpendicular to the look vector and requires correction for slope effects. Methods for normalization of the backscatter and interferometric correlation for ERS-1 SAR are presented.

  12. Infrared Astronomy After IRAS.

    PubMed

    Rieke, G H; Werner, M W; Thompson, R I; Becklin, E E; Hoffmann, W F; Houck, J R; Low, F J; Stein, W A; Witteborn, F C

    1986-02-21

    The 250,000 sources in the recently issued Infrared Astronomy Satellite (IRAS) all-sky infrared catalog are a challenge to astronomy. Many of these sources will be studied with existing and planned ground-based and airborne telescopes, but many others can no longer even be detected now that IRAS has ceased to operate. As anticipated by advisory panels of the National Academy of Sciences for a decade, study of the IRAS sources will require the Space Infrared Telescope Facility (SIRTF), a cooled, pointed telescope in space. This instrument may be the key to our understanding of cosmic birth-the formation of planets, stars, galaxies, active galactic nuclei, and quasars. Compared with IRAS and existing telescopes, SIRTF's power derives from a thousandfold gain in sensitivity over five octaves of the spectrum.

  13. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2012-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes. It will be a large (6.6m) cold (SDK) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. The science goals for JWST include the formation of the first stars and galaxies in the early universe; the chemical, morphological and dynamical buildup of galaxies and the formation of stars and planetary systems. Recently, the goals have expanded to include studies of dark energy, dark matter, active galactic nuclei, exoplanets and Solar System objects. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Near-Infrared Imager and Slitless Spectrograph will cover the wavelength range 0.6 to S microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. The observatory is confirmed for launch in 2018; the design is complete and it is in its construction phase. Recent progress includes the completion of the mirrors, the delivery of the first flight instruments and the start of the integration and test phase.

  14. The NASA Spitzer Space Telescope.

    PubMed

    Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

  15. The mass-metallicity and fundamental metallicity relations at z > 2 using very large telescope and Subaru near-infrared spectroscopy of zCOSMOS galaxies

    SciTech Connect

    Maier, C.; Ziegler, B. L.; Lilly, S. J.; Peng, Y.; Contini, T.; Pérez Montero, E.; Balestra, I.

    2014-09-01

    In the local universe, there is good evidence that, at a given stellar mass M, the gas-phase metallicity Z is anti-correlated with the star formation rate (SFR) of the galaxies. It has also been claimed that the resulting Z(M, SFR) relation is invariant with redshift—the so-called 'fundamental metallicity relation' (FMR). Given a number of difficulties in determining metallicities, especially at higher redshifts, the form of the Z(M, SFR) relation and whether it is really independent of redshift is still very controversial. To explore this issue at z > 2, we used VLT-SINFONI and Subaru-MOIRCS near-infrared spectroscopy of 20 zCOSMOS-deep galaxies at 2.1 < z < 2.5 to measure the strengths of up to five emission lines: [O II] λ3727, Hβ, [O III] λ5007, Hα, and [N II] λ6584. This near-infrared spectroscopy enables us to derive O/H metallicities, and also SFRs from extinction corrected Hα measurements. We find that the mass-metallicity relation (MZR) of these star-forming galaxies at z ≈ 2.3 is lower than the local Sloan Digital Sky Survey (SDSS) MZR by a factor of three to five, a larger change than found by Erb et al. using [N II]/Hα-based metallicities from stacked spectra. We discuss how the different selections of the samples and metallicity calibrations used may be responsible for this discrepancy. The galaxies show direct evidence that the SFR is still a second parameter in the MZR at these redshifts. However, determining whether the Z(M, SFR) relation is invariant with epoch depends on the choice of extrapolation used from local samples, because z > 2 galaxies of a given mass have much higher SFRs than the local SDSS galaxies. We find that the zCOSMOS galaxies are consistent with a non-evolving FMR if we use the physically motivated formulation of the Z(M, SFR) relation from Lilly et al., but not if we use the empirical formulation of Mannucci et al.

  16. The Mass-Metallicity and Fundamental Metallicity Relations at z > 2 Using Very Large Telescope and Subaru Near-infrared Spectroscopy of zCOSMOS Galaxies

    NASA Astrophysics Data System (ADS)

    Maier, C.; Lilly, S. J.; Ziegler, B. L.; Contini, T.; Pérez Montero, E.; Peng, Y.; Balestra, I.

    2014-09-01

    In the local universe, there is good evidence that, at a given stellar mass M, the gas-phase metallicity Z is anti-correlated with the star formation rate (SFR) of the galaxies. It has also been claimed that the resulting Z(M, SFR) relation is invariant with redshift—the so-called "fundamental metallicity relation" (FMR). Given a number of difficulties in determining metallicities, especially at higher redshifts, the form of the Z(M, SFR) relation and whether it is really independent of redshift is still very controversial. To explore this issue at z > 2, we used VLT-SINFONI and Subaru-MOIRCS near-infrared spectroscopy of 20 zCOSMOS-deep galaxies at 2.1 < z < 2.5 to measure the strengths of up to five emission lines: [O II] λ3727, Hβ, [O III] λ5007, Hα, and [N II] λ6584. This near-infrared spectroscopy enables us to derive O/H metallicities, and also SFRs from extinction corrected Hα measurements. We find that the mass-metallicity relation (MZR) of these star-forming galaxies at z ≈ 2.3 is lower than the local Sloan Digital Sky Survey (SDSS) MZR by a factor of three to five, a larger change than found by Erb et al. using [N II]/Hα-based metallicities from stacked spectra. We discuss how the different selections of the samples and metallicity calibrations used may be responsible for this discrepancy. The galaxies show direct evidence that the SFR is still a second parameter in the MZR at these redshifts. However, determining whether the Z(M, SFR) relation is invariant with epoch depends on the choice of extrapolation used from local samples, because z > 2 galaxies of a given mass have much higher SFRs than the local SDSS galaxies. We find that the zCOSMOS galaxies are consistent with a non-evolving FMR if we use the physically motivated formulation of the Z(M, SFR) relation from Lilly et al., but not if we use the empirical formulation of Mannucci et al. AND SUBARU

  17. Interferometric direct imaging properties of a BIGRE-DAM device in laboratory

    NASA Astrophysics Data System (ADS)

    Patru, Fabien; Antichi, Jacopo; Rabou, Patrick; Giro, Enrico; Farinato, Jacopo; Gratton, Raffaele; Vassallo, Daniele; Verinaud, Christophe; Mourard, Denis; Girard, Julien

    2016-08-01

    DAM (Discretized Aperture Mapping) is an original optical concept able to improve the performance in high angular resolution and high contrast imaging by the present class of large telescopes equipped with adaptive optics. By discretizing the entrance pupil of a large telescope into an array of many coherent sub-apertures, DAM provides unique imaging and filtering properties by means of spatial filtering and interferometric techniques. DAM can be achieved by means of single-mode fibers, integrated optic waveguides, pinholes, or simply with an innovative BIGRE optical device. BIGRE is formed of an afocal double micro-lenses array. In addition to the pupil discretization process by spatial filtering, BIGRE can also provide two other optical processes: the pupil densification or the pupil dilution. DAD (Discretized Aperture Densification) increase the sub-aperture sizes and is suitable to a hypertelescope, whereas DADI (Discretized Aperture Dilution Interferometry) reduces the sub-aperture sizes and turns a large telescope into a Fizeau interferometer. This paper deals with the first in-lab experiment at visible wavelength of BIGRE devices for the three configurations above. We study the point spread function (PSF) when observing a point-like object located either on-axis or at various off-axis positions across the field of view. Both interferometric and diffractive effects are described. The experimental measurements are in good agreement with the BIGRE theory. It results that BIGRE fulfils the requirements to carry out spatially filtered pupil discretization (DAM), with possible densification (DAD) or dilution (DADI).

  18. 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.

  19. Interferometric study of a machine tool

    NASA Astrophysics Data System (ADS)

    Hoefling, Roland; Vaclavik, Jaroslav; Neigebauer, Reimund

    1996-09-01

    This paper describes the use of a non-destructive optical technique, digital speckle pattern interferometry, for the deformation analysis of a machine tool. An interferometric set-up has been designed and measurements of the milling head deformation have been made on the horizontal single spindle milling machine center.

  20. Interferometric Synthetic Aperture Microwave Radiometers : an Overview

    NASA Technical Reports Server (NTRS)

    Colliander, Andreas; McKague, Darren

    2011-01-01

    This paper describes 1) the progress of the work of the IEEE Geoscience and Remote Sensing Society (GRSS) Instrumentation and Future Technologies Technical Committee (IFT-TC) Microwave Radiometer Working Group and 2) an overview of the development of interferometric synthetic aperture microwave radiometers as an introduction to a dedicated session.

  1. Quantum Limits in Interferometric GW Antennas

    NASA Technical Reports Server (NTRS)

    Romano, R.; Barone, F.; Maddalena, P.; Solimeno, S.; Zaccaria, F.; Manko, M. A.; Manko, V. I.

    1996-01-01

    We discuss a model for interferometric GW antennas illuminated by a laser beam and a vacuum squeezed field. The sensitivity of the antenna will depend on the properties of the radiation entering the two ports and on the optical characteristics of the interferometer components, e.g. mirrors, beam-splitter, lenses.

  2. Infrared Studies of AFGL Sources.

    DTIC Science & Technology

    1980-04-14

    displaced. We have recently used a small beam infrared photometer on the Wyoming Infrared Telescope to produce a set of isophotal maps of GL- 2636 which...reported herein, suggest that GL2636 ma1 be similar to the - Lco;plex in N42. 35 11. The Infrared Observation Isophotal maps of GL2636 were produced at

  3. On the origin of [Ne II] emission in young stars: mid-infrared and optical observations with the Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Baldovin-Saavedra, C.; Audard, M.; Carmona, A.; Güdel, M.; Briggs, K.; Rebull, L. M.; Skinner, S. L.; Ercolano, B.

    2012-07-01

    the disk. For the stars with VLT-UVES observations, in several cases, the optical forbidden line profiles and shifts are very similar to the profile of the [Ne II] line, suggesting that the lines are emitted in the same region. A general trend observed with VISIR is a lower line flux when compared with the fluxes obtained with Spitzer. We found no correlation between the line full-width at half maximum and the line peak velocity. The [Ne II] line remains undetected in a large part of the sample, an indication that the emission detected with Spitzer in those stars is likely extended. Based on observations made with ESO Telescopes Kueyen/UT2 and Melipal/UT3 at the Paranal Observatory under programs ID 083.C-0471, 084.C-1062, 086.C-0911, and 286.C-5038.Appendix A is available in electronic form at http://www.aanda.org

  4. Beyond the Hubble Space Telescope: Early Development of the Next Generation Space Telescope

    NASA Astrophysics Data System (ADS)

    Smith, Robert W.; Patrick McCray, W.

    In this paper we investigate the early history of what was at first called the Next Generation Space Telescope, later to be renamed the James Webb Space Telescope. We argue that the initial ideas for such a Next Generation Space Telescope were developed in the context of the planning for a successor to the Hubble Space Telescope. Much the most important group of astronomers and engineers examining such a successor was based at the Space Telescope Science Institute in Baltimore. By the late 1980s, they had fashioned concepts for a successor that would work in optical, ultraviolet and infrared wavelengths, concepts that would later be regarded as politically unrealistic given the costs associated with them. We also explore how the fortunes of the planned Next Generation Space Telescope were intimately linked to that of its "parent," the Hubble Space Telescope.

  5. The Segmented Aperture Interferometric Nulling Testbed (SAINT) I: overview and air-side system description

    NASA Astrophysics Data System (ADS)

    Hicks, Brian A.; Lyon, Richard G.; Petrone, Peter; Ballard, Marlin; Bolcar, Matthew R.; Bolognese, Jeff; Clampin, Mark; Dogoda, Peter; Dworzanski, Daniel; Helmbrecht, Michael A.; Koca, Corina; Shiri, Ron

    2016-07-01

    This work presents an overview of the Segmented Aperture Interferometric Nulling Testbed (SAINT), a project that will pair an actively-controlled macro-scale segmented mirror with the Visible Nulling Coronagraph (VNC). SAINT will incorporate the VNC's demonstrated wavefront sensing and control system to refine and quantify end-to-end high-contrast starlight suppression performance. This pathfinder testbed will be used as a tool to study and refine approaches to mitigating instabilities and complex diffraction expected from future large segmented aperture telescopes.

  6. Kunlun Dark Universe Survey Telescope

    NASA Astrophysics Data System (ADS)

    Zhu, Yongtian; Wang, Lifan; Yuan, Xiangyan; Gu, Bozhong; Li, Xinnan; Yang, Shihai; Gong, Xuefei; Du, Fujia; Qi, Yongjun; Xu, Lingzhe

    2014-07-01

    Chinese Antarctic Observatory has been listed as National large research infrastructure during twelfth five-year plan. Kunlun Dark Universe Survey Telescope, one of two major facility of Chinese Antarctic Observatory, is a 2.5-meter optic/infrared telescope and will be built at the Chinese Antarctic Kunlun Station. It is intended to take advantage of the exceptional seeing conditions, as well as the low temperature reducing background for infrared observations. KDUST will adopt an innovative optical system, which can deliver very good image quality over a 2 square degree flat field of view. All of parts of it have been designed carefully to endure the extremely harsh environment. KDUST will be perched on a 14.5-meter-high tower to lift it above the turbulence layer. In this paper, preliminary design and key technology pre-research of KDUST will be introduced.

  7. Quantum telescope: feasibility and constraints.

    PubMed

    Kurek, A R; Pięta, T; Stebel, T; Pollo, A; Popowicz, A

    2016-03-15

    The quantum telescope is a recent idea aimed at beating the diffraction limit of spaceborne telescopes and possibly other distant target imaging systems. There is no agreement yet on the best setup of such devices, but some configurations have already been proposed. In this Letter we characterize the predicted performance of quantum telescopes and their possible limitations. Our extensive simulations confirm that the presented model of such instruments is feasible and the device can provide considerable gains in the angular resolution of imaging in the UV, optical, and infrared bands. We argue that it is generally possible to construct and manufacture such instruments using the latest or soon to be available technology. We refer to the latest literature to discuss the feasibility of the proposed QT system design.

  8. Telescopes on the Moon or pie in the sky?

    NASA Technical Reports Server (NTRS)

    Pilcher, Carl B.

    1992-01-01

    The question is examined of whether it makes sense to believe that there will one day be an interferometric array of telescopes on the Moon. The question is really one of national commitment to a lunar base, since it is not likely that a scientific undertaking of this magnitude would occur in the absence of permanent human presence on the Moon. A discussion is also given of the real possibility if the exploration of space should be a multinational effort.

  9. 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.

  10. Concept for a Large Space Telescope for Detailed Spectroscopy of Terrestrial exo-planets

    NASA Astrophysics Data System (ADS)

    Angel, J. R. P.; Woolf, N. J.; Burge, J. H.

    1998-12-01

    Once terrestrial planets of other stars are detected, cryogenic space telescopes of large collecting area will be needed to obtain detailed atmospheric spectra in the thermal infrared. Our concept is for an ultralightweight telescope with area approaching 1000 m(2) , made from large flat panels of stretched plastic membrane. Thin reflective material held in tension from points around a plane perimeter is fundamentally stable; its flat shape is not critically dependent on tension, and will hold even against penetration by micrometeorites. The perimeter support points would be actively controlled to maintain their co-planarity. We envisage about ten panels each about 10 m square, arranged on a rigid carbon composite truss to approximate a 100 m x 10 m mirror with 1 km focal length. A separate free-flyer at the quasi-focus would complete the telescope. Where all the beams from the target star overlap, a 10 m concave secondary would be used to form an image of the primary array at about 1/10 scale, and slightly below the plane of incoming beams. At each panel image would be a 1 m tertiary, suitably shaped so as to recollimate each individual starlight beam, or to bring all the beams to a common focus. From this point on the instrument might use the focus directly, or multi-aperture interferometric nulling techniques as described by Angel and Woolf. The unaberrated field will be large enough for exoplanet studies. The new technology goes beyond that needed for an 8 m NGST in two main ways: 1) need for thin metallized plastic of large size and uniform thickness and 2) capability to assemble or deploy in space the structure to support the panels.

  11. James Webb Space Telescope: large deployable cryogenic telescope in space

    NASA Astrophysics Data System (ADS)

    Lightsey, Paul A.; Atkinson, Charles; Clampin, Mark; Feinberg, Lee D.

    2012-01-01

    The James Webb Space Telescope (JWST) is an infrared space telescope designed to explore four major science themes: first light and reionization, the assembly of galaxies, the birth of stars and protoplanetary systems, and planetary systems and origins of life. JWST is a segmented architecture telescope with an aperture of 6.6 m. It will operate at cryogenic temperature (40 K), achieved via passive cooling, in an orbit about the Earth-Sun second Lagrange point (L2). Passive cooling is facilitated by means of a large sunshield that provides thermal isolation and protection from direct illumination from the Sun. The large size of the telescope and spacecraft systems require that they are stowed for launch in a configuration that fits the Ariane 5 fairing, and then deployed after launch. Routine wavefront sensing and control measurements are used to achieve phasing of the segmented primary mirror and initial alignment of the telescope. A suite of instruments will provide the capability to observe over a spectral range from 0.6- to 27-μm wavelengths with imaging and spectroscopic configurations. An overview is presented of the architecture and selected optical design features of JWST are described.

  12. Modeling Seven Years of Event Horizon Telescope Observations with Radiatively Inefficient Accretion Flow Models

    NASA Astrophysics Data System (ADS)

    Broderick, Avery E.; Fish, Vincent L.; Johnson, Michael D.; Rosenfeld, Katherine; Wang, Carlos; Doeleman, Sheperd S.; Akiyama, Kazunori; Johannsen, Tim; Roy, Alan L.

    2016-04-01

    An initial three-station version of the Event Horizon Telescope, a millimeter-wavelength very-long baseline interferometer, has observed Sagittarius A* (Sgr A*) repeatedly from 2007 to 2013, resulting in the measurement of a variety of interferometric quantities. Of particular importance is that there is now a large set of closure phases measured over a number of independent observing epochs. We analyze these observations within the context of a realization of semi-analytic radiatively inefficient disk models, implicated by the low luminosity of Sgr A*. We find a broad consistency among the various observing epochs and between different interferometric data types, with the latter providing significant support for this class of model of Sgr A*. The new data significantly tighten existing constraints on the spin magnitude and its orientation within this model context, finding a spin magnitude of a={0.10}-0.10-0.10+0.30+0.56, an inclination with respect to the line of sight of θ ={60^\\circ }-{8^\\circ -{13}^\\circ }+{5^\\circ +{10}^\\circ }, and a position angle of ξ ={156^\\circ }-{17^\\circ -{27}^\\circ }+{10^\\circ +{14}^\\circ } east of north. These are in good agreement with previous analyses. Notably, the previous 180° degeneracy in the position angle has now been conclusively broken by the inclusion of the closure-phase measurements. A reflection degeneracy in the inclination remains, permitting two localizations of the spin vector orientation, one of which is in agreement with the orbital angular momentum of the infrared gas cloud G2 and the clockwise disk of young stars. This may support a relationship between Sgr A*'s accretion flow and these larger-scale features.

  13. Proceedings of the Second Infrared Detector Technology Workshop

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R. (Compiler)

    1986-01-01

    The workshop focused on infrared detector, detector array, and cryogenic electronic technologies relevant to low-background space astronomy. Papers are organized into the following categories: discrete infrared detectors and readout electronics; advanced bolometers; intrinsic integrated infrared arrays; and extrinsic integrated infrared arrays. Status reports on the Space Infrared Telescope Facility (SIRTF) and Infrared Space Observatory (ISO) programs are also included.

  14. Near-field Interferometric Imaging of Lightning

    NASA Astrophysics Data System (ADS)

    Stock, M.; Wu, T.; Akiyama, Y.; Kawasaki, Z.; Ushio, T.

    2015-12-01

    In the past, lightning interferometric mapping systems assumed that a source is very far from the measurement location. The assumption greatly simplifies the mathematics needed to locate the source, but the resulting source positions are limited to two spatial dimensions (azimuth and elevation). For short baseline systems, this assumption is very good because the source is almost always much farther away than the diameter of the array, making three-dimensional location all but impossible. By removing the far-field assumption, if the array is large enough it is possible to locate the source in three spatial dimensions using purely interferometric techniques. The purely interferometric method is quite different from the more typical time-of-arrival method. Instead of measuring arrival times or time differences of the radiation arriving at each station, a volume is imaged over a some integration period and then searched for a source. It is not necessary to know that a source exists in the integration period for the interferometric imaging technique to produce a well defined solution. Interferometric imaging can locate sources buried in noise, can locate both continuous and impulsive emission, and is capable of locating multiple simultaneously radiating sources. If the waveforms are corrected for propagation delay to the search volume, the integration period can be made arbitrarily small (limited only by the frequencies being observed), allowing the progression of lightning to be examined in detail. Near-field interferometry works equally well on a wide range of different signal types, from the LF to VHF bands in radio, or even on acoustic emissions from lightning. Near-field imaging can be used to correct the angular locations of short baseline systems when a source is very close to the array, or to produce full three-dimensional maps of lightning with long baseline arrays. Presented here are preliminary results of applying near-field interferometric imaging to the

  15. 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

  16. First-light LBT Nulling Interferometric Observations: Warm Exozodiacal Dust Resolved within a Few AU of η Crv

    NASA Astrophysics Data System (ADS)

    Defrère, D.; Hinz, P. M.; Skemer, A. J.; Kennedy, G. M.; Bailey, V. P.; Hoffmann, W. F.; Mennesson, B.; Millan-Gabet, R.; Danchi, W. C.; Absil, O.; Arbo, P.; Beichman, C.; Brusa, G.; Bryden, G.; Downey, E. C.; Durney, O.; Esposito, S.; Gaspar, A.; Grenz, P.; Haniff, C.; Hill, J. M.; Lebreton, J.; Leisenring, J. M.; Males, J. R.; Marion, L.; McMahon, T. J.; Montoya, M.; Morzinski, K. M.; Pinna, E.; Puglisi, A.; Rieke, G.; Roberge, A.; Serabyn, E.; Sosa, R.; Stapeldfeldt, K.; Su, K.; Vaitheeswaran, V.; Vaz, A.; Weinberger, A. J.; Wyatt, M. C.

    2015-01-01

    We report on the first nulling interferometric observations with the Large Binocular Telescope Interferometer (LBTI), resolving the N' band (9.81-12.41 μm) emission around the nearby main-sequence star η Crv (F2V, 1-2 Gyr). The measured source null depth amounts to 4.40% ± 0.35% over a field-of-view of 140 mas in radius (~2.6 AU for the distance of η Crv) and shows no significant variation over 35° of sky rotation. This relatively low null is unexpected given the total disk to star flux ratio measured by the Spitzer Infrared Spectrograph (IRS; ~23% across the N' band), suggesting that a significant fraction of the dust lies within the central nulled response of the LBTI (79 mas or 1.4 AU). Modeling of the warm disk shows that it cannot resemble a scaled version of the solar zodiacal cloud unless it is almost perpendicular to the outer disk imaged by Herschel. It is more likely that the inner and outer disks are coplanar and the warm dust is located at a distance of 0.5-1.0 AU, significantly closer than previously predicted by models of the IRS spectrum (~3 AU). The predicted disk sizes can be reconciled if the warm disk is not centrosymmetric, or if the dust particles are dominated by very small grains. Both possibilities hint that a recent collision has produced much of the dust. Finally, we discuss the implications for the presence of dust for the distance where the insolation is the same as Earth's (2.3 AU).

  17. FIRST-LIGHT LBT NULLING INTERFEROMETRIC OBSERVATIONS: WARM EXOZODIACAL DUST RESOLVED WITHIN A FEW AU OF η Crv

    SciTech Connect

    Defrère, D.; Hinz, P. M.; Skemer, A. J.; Bailey, V. P.; Hoffmann, W. F.; Arbo, P.; Brusa, G.; Downey, E. C.; Durney, O.; Gaspar, A.; Grenz, P.; Kennedy, G. M.; Mennesson, B.; Bryden, G.; Millan-Gabet, R.; Beichman, C.; Danchi, W. C.; Absil, O.; Esposito, S.; Haniff, C.; and others

    2015-01-20

    We report on the first nulling interferometric observations with the Large Binocular Telescope Interferometer (LBTI), resolving the N' band (9.81-12.41 μm) emission around the nearby main-sequence star η Crv (F2V, 1-2 Gyr). The measured source null depth amounts to 4.40% ± 0.35% over a field-of-view of 140 mas in radius (∼2.6 AU for the distance of η Crv) and shows no significant variation over 35° of sky rotation. This relatively low null is unexpected given the total disk to star flux ratio measured by the Spitzer Infrared Spectrograph (IRS; ∼23% across the N' band), suggesting that a significant fraction of the dust lies within the central nulled response of the LBTI (79 mas or 1.4 AU). Modeling of the warm disk shows that it cannot resemble a scaled version of the solar zodiacal cloud unless it is almost perpendicular to the outer disk imaged by Herschel. It is more likely that the inner and outer disks are coplanar and the warm dust is located at a distance of 0.5-1.0 AU, significantly closer than previously predicted by models of the IRS spectrum (∼3 AU). The predicted disk sizes can be reconciled if the warm disk is not centrosymmetric, or if the dust particles are dominated by very small grains. Both possibilities hint that a recent collision has produced much of the dust. Finally, we discuss the implications for the presence of dust for the distance where the insolation is the same as Earth's (2.3 AU)

  18. 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.

  19. Far-Infrared Space Interferometers: Future Windows on Star and Planet Formation

    NASA Technical Reports Server (NTRS)

    Leisawitz, David

    2004-01-01

    Far-IR space interferometers will provide observational access to a spectral region containing many important cooling and diagnostic spectral lines and the bulk of the thermal emission from dust at angular scales critical to advancing our understanding of the star and planet formation process. We will describe concepts for the Space Infrared Interferometric Telescope (SPIRIT) and the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS). Both of these candidate NASA missions are imaging and spectral Michelson interferometers operating in the wavelength range -40 - 800 microns. SPIRIT, which could be launched in a decade as a NASA Origins Probe, is built on a deployable boom and has a maximum baseline length of -30 - 50 m, yielding sub-arcsecond resolution in the far-IR. SPIRIT will thus provide far-IR/sub-mm measurements complementary to the near- and mid-IR measurements obtainable with the James Webb Space Telescope (JWST), and well matched to JWST observations in angular resolution. Ultimately SPECS, a NASA Vision Mission, will use formation flying to attain baseline lengths up to 1 km, and thus angular resolution comparable to that of the Hubble Space Telescope and the Atacama Large Millimeter Array. We will report preliminary results of the NASA-sponsored SPIRIT and SPECS mission studies, which are now underway.

  20. The evolved circumbinary disk of AC Herculis: a radiative transfer, interferometric, and mineralogical study

    NASA Astrophysics Data System (ADS)

    Hillen, M.; de Vries, B. L.; Menu, J.; Van Winckel, H.; Min, M.; Mulders, G. D.

    2015-06-01

    Context. Many post-asymptotic giant branch (post-AGB) stars in binary systems have an infrared (IR) excess arising from a dusty circumbinary disk. The disk formation, current structure, and further evolution are, however, poorly understood. Aims: We aim to constrain the structure of the circumstellar material around the post-AGB binary and RV Tauri pulsator AC Her. We want to constrain the spatial distribution of the amorphous and of the crystalline dust. Methods: We present very high-quality mid-IR interferometric data that were obtained with the MIDI/VLTI instrument. We analyze the MIDI visibilities and differential phases in combination with the full spectral energy distribution, using the MCMax radiative transfer code, to find a good structure model of AC Her's circumbinary disk. We include a grain size distribution and midplane settling of dust self-consistently in our models. The spatial distribution of crystalline forsterite in the disk is investigated with the mid-IR features, the 69 μm band and the 11.3 μm signatures in the interferometric data. Results: All the data are well fitted by our best model. The inclination and position angle of the disk are precisely determined at i = 50 ± 8° and PA = 305 ± 10°. We firmly establish that the inner disk radius is about an order of magnitude larger than the dust sublimation radius. The best-fit dust grain size distribution shows that significant grain growth has occurred, with a significant amount of mm-sized grains now being settled to the midplane of the disk. A large total dust mass ≥10-3 M⊙ is needed to fit the mm fluxes. By assuming αturb = 0.01, a good fit is obtained with a small grain size power law index of 3.25, combined with a small gas/dust ratio ≤10. The resulting gas mass is compatible with recent estimates employing direct gas diagnostics. The spatial distribution of the forsterite is different from the amorphous dust, as more warm forsterite is needed in the surface layers of the inner

  1. Fast interferometric second harmonic generation microscopy

    PubMed Central

    Bancelin, Stéphane; Couture, Charles-André; Légaré, Katherine; Pinsard, Maxime; Rivard, Maxime; Brown, Cameron; Légaré, François

    2016-01-01

    We report the implementation of fast Interferometric Second Harmonic Generation (I-SHG) microscopy to study the polarity of non-centrosymmetric structures in biological tissues. Using a sample quartz plate, we calibrate the spatially varying phase shift introduced by the laser scanning system. Compensating this phase shift allows us to retrieve the correct phase distribution in periodically poled lithium niobate, used as a model sample. Finally, we used fast interferometric second harmonic generation microscopy to acquire phase images in tendon. Our results show that the method exposed here, using a laser scanning system, allows to recover the polarity of collagen fibrils, similarly to standard I-SHG (using a sample scanning system), but with an imaging time about 40 times shorter. PMID:26977349

  2. Polarization-sensitive interferometric synthetic aperture microscopy

    PubMed Central

    South, Fredrick A.; Liu, Yuan-Zhi; Xu, Yang; Shemonski, Nathan D.; Carney, P. Scott; Boppart, Stephen A.

    2015-01-01

    Three-dimensional optical microscopy suffers from the well-known compromise between transverse resolution and depth-of-field. This is true for both structural imaging methods and their functional extensions. Interferometric synthetic aperture microscopy (ISAM) is a solution to the 3D coherent microscopy inverse problem that provides depth-independent transverse resolution. We demonstrate the extension of ISAM to polarization sensitive imaging, termed polarization-sensitive interferometric synthetic aperture microscopy (PS-ISAM). This technique is the first functionalization of the ISAM method and provides improved depth-of-field for polarization-sensitive imaging. The basic assumptions of polarization-sensitive imaging are explored, and refocusing of birefringent structures is experimentally demonstrated. PS-ISAM enables high-resolution volumetric imaging of birefringent materials and tissue. PMID:26648593

  3. Interferometric diagnostics for magnetic spots detection

    NASA Astrophysics Data System (ADS)

    Ligi, R.

    2014-09-01

    The signature of activity in general, and of stellar magnetic spots in particular, is present in every measurements, including interferometric ones. Indeed, stellar spots can be found on many stellar surfaces, their size and number varying according to their host's magnetic field and rotational velocity. To correctly determine stellar parameters, it is thus necessary to determine and extract stellar activity's signals. Interferometric observables are disturbed by activity, and this observing technique thus constitutes a good way of probing stellar surface. However, magnetic spots sometimes mimic other phenomenon, like a transiting exoplanet. In that case, the combination of several observing techniques, like photometry and interferometry, is mandatory to extract the planetary signal from the spot's one, and then characterize the exoplanet.

  4. Deconvolution of interferometric data using interior point iterative algorithms

    NASA Astrophysics Data System (ADS)

    Theys, C.; Lantéri, H.; Aime, C.

    2016-09-01

    We address the problem of deconvolution of astronomical images that could be obtained with future large interferometers in space. The presentation is made in two complementary parts. The first part gives an introduction to the image deconvolution with linear and nonlinear algorithms. The emphasis is made on nonlinear iterative algorithms that verify the constraints of non-negativity and constant flux. The Richardson-Lucy algorithm appears there as a special case for photon counting conditions. More generally, the algorithm published recently by Lanteri et al. (2015) is based on scale invariant divergences without assumption on the statistic model of the data. The two proposed algorithms are interior-point algorithms, the latter being more efficient in terms of speed of calculation. These algorithms are applied to the deconvolution of simulated images corresponding to an interferometric system of 16 diluted telescopes in space. Two non-redundant configurations, one disposed around a circle and the other on an hexagonal lattice, are compared for their effectiveness on a simple astronomical object. The comparison is made in the direct and Fourier spaces. Raw "dirty" images have many artifacts due to replicas of the original object. Linear methods cannot remove these replicas while iterative methods clearly show their efficacy in these examples.

  5. Analysis of the interferometric Ronchi test.

    PubMed

    Malacara, D

    1990-09-01

    It is well known that the Ronchi test has two equivalent interpretations, Physical, as an interferometer, or geometrical, as if the fringes were just shadows from the fringes on the ruling. The second interpretation is nearly always used in practice because it is simpler. However, the disadvantage is that the irradiance profile of the fringes cannot be calculated with this theory. Here, the interferometric interpretation of the test will be used to obtain the irradiance profile and the sharpness of the fringes.

  6. TE/TM Simulations of Interferometric Measurements

    NASA Technical Reports Server (NTRS)

    Houshmand, Bijan

    2000-01-01

    Interferometric synthetic aperture radar (IFSAR) measurements at X-, C-, L-, and P-band are used to derive ground topography at meter level resolution. Interpretation of the derived topography requires attention due to the complex interaction of the radar signal with ground cover. The presence of penetrable surfaces such as vegetation, and tree canopies poses a challenge since the depth of penetration depends on a number of parameters such as the operating radar frequency, polarization, incident angle, as well as terrain structure. The dependence of the reconstructed topography on polarization may lead to the characterization of the ground cover. Simulation of interferometric measurements is useful for interpretation of the derived topography (B. Houshmand, Proceedings of URSI, 314, 1997). In this talk , time domain simulations for interferometric measurement for TE- and TM- polarization are presented. Time domain simulation includes the effects of the surface material property as well geometry comparable the radar signal wavelength (B. Houshmand, Proceedings of the URSI, 25, 1998). The IFSAR simulation is carried out in two steps. First, the forward scattering data is generated based on full wave analysis. Next, the electromagnetic information is inverted to generate surface topography. This inversion is based on the well known IFSAR processing technique which is composed of signal compression, and formation of an interferogram. The full wave forward scattering data is generated by the scattered-field formulation of the FDTD algorithm. The simulation is carried out by exciting the computational domain by a radar signal. The scattered field is then computed and translated to the receiving interferometric antennas using the time-domain Huygen's principle. The inversion process starts by compressing the time-domain data. The range compressed data from both receivers are then coregistered to form an interferogram. The resulting interferogram is then related to the

  7. Speckle-interferometric camera for displacement measurements

    NASA Astrophysics Data System (ADS)

    Klumpp, P. A.; Schnack, E.

    1990-12-01

    A simple setup of standard optical elements comparable to a shearographic camera can be used used to record speckle interferograms with a fast lens. Rigid-body translations of the object are compensated for by a reference mirror attached to the object; the method requires only moderate stability and resolution of the storage medium (film). Interferogram reconstruction is possible with white light. Hence the method unites advances of different holographic and speckle-interferometric setups.

  8. DUST EXTINCTION FROM BALMER DECREMENTS OF STAR-FORMING GALAXIES AT 0.75 {<=} z {<=} 1.5 WITH HUBBLE SPACE TELESCOPE/WIDE-FIELD-CAMERA 3 SPECTROSCOPY FROM THE WFC3 INFRARED SPECTROSCOPIC PARALLEL SURVEY

    SciTech Connect

    Dominguez, A.; Siana, B.; Masters, D.; Henry, A. L.; Martin, C. L.; Scarlata, C.; Bedregal, A. G.; Malkan, M.; Ross, N. R.; Atek, H.; Colbert, J. W.; Teplitz, H. I.; Rafelski, M.; McCarthy, P.; Hathi, N. P.; Dressler, A.; Bunker, A.

    2013-02-15

    Spectroscopic observations of H{alpha} and H{beta} emission lines of 128 star-forming galaxies in the redshift range 0.75 {<=} z {<=} 1.5 are presented. These data were taken with slitless spectroscopy using the G102 and G141 grisms of the Wide-Field-Camera 3 (WFC3) on board the Hubble Space Telescope as part of the WFC3 Infrared Spectroscopic Parallel survey. Interstellar dust extinction is measured from stacked spectra that cover the Balmer decrement (H{alpha}/H{beta}). We present dust extinction as a function of H{alpha} luminosity (down to 3 Multiplication-Sign 10{sup 41} erg s{sup -1}), galaxy stellar mass (reaching 4 Multiplication-Sign 10{sup 8} M {sub Sun }), and rest-frame H{alpha} equivalent width. The faintest galaxies are two times fainter in H{alpha} luminosity than galaxies previously studied at z {approx} 1.5. An evolution is observed where galaxies of the same H{alpha} luminosity have lower extinction at higher redshifts, whereas no evolution is found within our error bars with stellar mass. The lower H{alpha} luminosity galaxies in our sample are found to be consistent with no dust extinction. We find an anti-correlation of the [O III] {lambda}5007/H{alpha} flux ratio as a function of luminosity where galaxies with L {sub H{alpha}} < 5 Multiplication-Sign 10{sup 41} erg s{sup -1} are brighter in [O III] {lambda}5007 than H{alpha}. This trend is evident even after extinction correction, suggesting that the increased [O III] {lambda}5007/H{alpha} ratio in low-luminosity galaxies is likely due to lower metallicity and/or higher ionization parameters.

  9. Herschel far-infrared photometry of the Swift Burst Alert Telescope active galactic nuclei sample of the local universe - III. Global star-forming properties and the lack of a connection to nuclear activity

    NASA Astrophysics Data System (ADS)

    Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio; Koss, Michael J.; Barger, Amy J.; Cowie, Lennox L.

    2017-04-01

    We combine the Herschel Space Observatory PACS (Photoconductor Array Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging Receiver) photometry with archival WISE (Wide-field Infrared Survey Explorer) photometry to construct the spectral energy distributions (SEDs) for over 300 local (z < 0.05), ultrahard X-ray (14-195 keV) selected active galactic nuclei (AGN) from the Swift Burst Alert Telescope (BAT) 58-month catalogue. Using a simple analytical model that combines an exponentially cutoff power law with a single temperature modified blackbody, we decompose the SEDs into a host galaxy and AGN component. We calculate dust masses, dust temperatures, and star formation rates (SFRs) for our entire sample and compare them to a stellar mass-matched sample of local non-AGN galaxies. We find AGN host galaxies have systematically higher dust masses, dust temperatures, and SFRs due to the higher prevalence of late-type galaxies to host an AGN, in agreement with previous studies of the Swift/BAT AGN. We provide a scaling to convert X-ray luminosities into 8-1000 μm AGN luminosities, as well as determine the best mid-to-far IR colours for identifying AGN-dominated galaxies in the IR regime. We find that for nearly 30 per cent of our sample, the 70 μm emission contains a significant contribution from the AGN (>0.5), especially at higher luminosities (L14 - 195 keV > 1042.5 erg s-1). Finally, we measure the local SFR-AGN luminosity relationship, finding a slope of 0.18, large scatter (0.37 dex), and no evidence for an upturn at high AGN luminosity. We conclude with a discussion on the implications of our results within the context of galaxy evolution with and without AGN feedback.

  10. Bayes classification of interferometric TOPSAR data

    NASA Technical Reports Server (NTRS)

    Michel, T. R.; Rodriguez, E.; Houshmand, B.; Carande, R.

    1995-01-01

    We report the Bayes classification of terrain types at different sites using airborne interferometric synthetic aperture radar (INSAR) data. A Gaussian maximum likelihood classifier was applied on multidimensional observations derived from the SAR intensity, the terrain elevation model, and the magnitude of the interferometric correlation. Training sets for forested, urban, agricultural, or bare areas were obtained either by selecting samples with known ground truth, or by k-means clustering of random sets of samples uniformly distributed across all sites, and subsequent assignments of these clusters using ground truth. The accuracy of the classifier was used to optimize the discriminating efficiency of the set of features that was chosen. The most important features include the SAR intensity, a canopy penetration depth model, and the terrain slope. We demonstrate the classifier's performance across sites using a unique set of training classes for the four main terrain categories. The scenes examined include San Francisco (CA) (predominantly urban and water), Mount Adams (WA) (forested with clear cuts), Pasadena (CA) (urban with mountains), and Antioch Hills (CA) (water, swamps, fields). Issues related to the effects of image calibration and the robustness of the classification to calibration errors are explored. The relative performance of single polarization Interferometric data classification is contrasted against classification schemes based on polarimetric SAR data.

  11. Monitoring LMXBs with the Faulkes Telescope

    NASA Astrophysics Data System (ADS)

    Lewis, Fraser; Russell, D. M.; Fender, R. P.; Roche, P.

    The Faulkes Telescope Project is the educational arm of the Las Cumbres Observatory Global Telescope Network (LCOGT). It currently has two 2-metre robotic telescopes, located at Haleakala on Maui (FT North) and Siding Spring in Australia (FT South). It is planned to increase this to six 2-metre telescopes in the future, complemented by a network of 30-40 smaller (0.4 - 1 metre) telescopes providing 24 hour coverage of both northern and southern hemispheres. We are undertaking a monitoring project of 10 low-mass X-ray binaries (LMXBs) using FT North to study the optical continuum behaviour of X-ray transients in quiescence. The introduction of FT South in September 2006 allows us to extend this monitoring to include 17 southern hemisphere LMXBs. With new instrumentation, we also intend to expand this monitoring to include both infrared wavelengths and spectroscopy.

  12. MI-6: Michigan interferometry with six telescopes

    NASA Astrophysics Data System (ADS)

    Monnier, John D.; Anderson, M.; Baron, F.; Berger, D. H.; Che, X.; Eckhause, T.; Kraus, S.; Pedretti, E.; Thureau, N.; Millan-Gabet, R.; ten Brummelaar, T.; Irwin, P.; Zhao, M.

    2010-07-01

    Based on the success of four-telescope imaging with the Michigan Infrared Combiner (MIRC) on the CHARA Array, our Michigan-based group will now upgrade our system to combine all six CHARA telescope simultaneously. In order to make this observationally efficient, we have had to improve a number of subsystems and commission new ones, including the new CHAMP fringe tracker, the introduction of photometric channels, the upgrading of the realtime operating systems, and the obvious hardware and software upgrades of the control system and the data pipeline. Here we will discuss the advantages of six-telescope operation, outline our upgrade plans and discuss our current progress.

  13. 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.

  14. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched in about 5 years into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  15. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  16. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched in about 5 years into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Proto planetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  17. Simultaneous water vapor and dry air optical path length measurements and compensation with the large binocular telescope interferometer

    NASA Astrophysics Data System (ADS)

    Defrère, D.; Hinz, P.; Downey, E.; Böhm, M.; Danchi, W. C.; Durney, O.; Ertel, S.; Hill, J. M.; Hoffmann, W. F.; Mennesson, B.; Millan-Gabet, R.; Montoya, M.; Pott, J.-U.; Skemer, A.; Spalding, E.; Stone, J.; Vaz, A.

    2016-08-01

    The Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 microns). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI/MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illustrate the feasibility of our feedforward approach to stabilize the path length fluctuations seen by the LBTI nuller.

  18. The VLTI/MIDI survey of massive young stellar objects . Sounding the inner regions around intermediate- and high-mass young stars using mid-infrared interferometry

    NASA Astrophysics Data System (ADS)

    Boley, Paul A.; Linz, Hendrik; van Boekel, Roy; Henning, Thomas; Feldt, Markus; Kaper, Lex; Leinert, Christoph; Müller, André; Pascucci, Ilaria; Robberto, Massimo; Stecklum, Bringfried; Waters, L. B. F. M.; Zinnecker, Hans

    2013-10-01

    Context. Because of inherent difficulties involved in observations and numerical simulations of the formation of massive stars, an understanding of the early evolutionary phases of these objects remains elusive. In particular, observationally probing circumstellar material at distances ≲100 AU from the central star is exceedingly difficult, as such objects are rare (and thus, on average, far away) and typically deeply embedded. Long-baseline mid-infrared interferometry provides one way of obtaining the necessary spatial resolution at appropriate wavelengths for studying this class of objects; however, interpreting such observations is often difficult due to sparse spatial-frequency coverage. Aims: We aim to characterize the distribution and composition of circumstellar material around young massive stars and to investigate exactly which physical structures in these objects are probed by long-baseline mid-infrared interferometric observations. Methods: We used the two-telescope interferometric instrument MIDI of the Very Large Telescope Interferometer of the European Southern Observatory to observe a sample of 24 intermediate- and high-mass young stellar objects in the N band (8-13 μm). We had successful fringe detections for 20 objects and present spectrally-resolved correlated fluxes and visibility levels for projected baselines of up to 128 m. We fit the visibilities with geometric models to derive the sizes of the emitting regions, as well as the orientation and elongation of the circumstellar material. Fourteen objects in the sample show the 10 μm silicate feature in absorption in the total and correlated flux spectra. For 13 of these objects, we were able to fit the correlated flux spectra with a simple absorption model, allowing us to constrain the composition and absorptive properties of the circumstellar material. Results: Nearly all of the massive young stellar objects observed show significant deviations from spherical symmetry at mid-infrared

  19. Alignment and Performance of the Infrared Multi-Object Spectrometer

    NASA Technical Reports Server (NTRS)

    Connelly, Joseph A.; Ohl, Raymond G.; Mentzell, J. Eric; Madison, Timothy J.; Hylan, Jason E.; Mink, Ronald G.; Saha, Timo T.; Tveekrem, June L.; Sparr, Leroy M.; Chambers, V. John; Fitzgerald, Danetter; Greenhouse, Matthew A.; MacKenty, John W.

    2004-01-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator class instrument for the Kitt Peak National Observatory 4 and 2.1 meter telescopes. IRMOS is a near-IR (0.8 - 2.5 micron) spectrometer with low-to mid-resolving power (R = 300 - 3000). IRMOS produces simultaneous spectra of approximately 100 objects in its 2.8 x 2.0 arc-min field of view (4 m telescope) using a commercial Micro Electro-Mechanical Systems (MEMS) micro-mirror array (MMA) from Texas Instruments. The IRMOS optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the MMA field stop, and the spectrograph images the MMA onto the detector. We describe ambient breadboard subsystem alignment and imaging performance of each stage independently, and ambient imaging performance of the fully assembled instrument. Interferometric measurements of subsystem wavefront error serve as a qualitative alignment guide, and are accomplished using a commercial, modified Twyman-Green laser unequal path interferometer. Image testing provides verification of the optomechanical alignment method and a measurement of near-angle scattered light due to mirror small-scale surface error. Image testing is performed at multiple field points. A mercury-argon pencil lamp provides a spectral line at 546.1 nanometers, a blackbody source provides a line at 1550 nanometers, and a CCD camera and IR camera are used as detectors. We use commercial optical modeling software to predict the point-spread function and its effect on instrument slit transmission and resolution. Our breadboard and instrument level test results validate this prediction. We conclude with an instrument performance prediction for cryogenic operation and first light in late 2003.

  20. State-of-art pulsar studies using interferometric arrays

    NASA Astrophysics Data System (ADS)

    Roy, Jayanta

    The new flexible and powerful software back-end (GSB) opens up the possibility of new regimes of pulsar studies with interferometric arrays like the GMRT, as exemplified by two unique techniques - a gating correlator for millisecond pulsars (MSPs) and a multi-pixel beamformer. We have developed a coherently dedispersed MSP gating correlator at the GMRT motivated by the requirement of localising the newly discovered faint Fermi MSPs. This imaging technique uses the dedispersed visibility data folded with period, acceleration and jerk. We could localise the tighter and fainter binary MSPs in the ON-OFF image plane, even outside the HPBW of GMRT. This tool enables study of unique aspects of MSP population (also pulsars in general) using present and up-coming interferometric arrays (LEAP, ASKAP, MeerKAT, SKA etc). Study the off-pulse emission from the gamma-ray selected MSPs using the MSP gating imaging technique can provide additional constrain on the emission region in pulsar magnetosphere. Moreover, proper motion study of the fainter pulsars is highly benefited from the sensitivity enhancement on the gated image plane. We have also developed a multi-pixel beamformer technique, which is able to look for pulsations much more efficiently over a larger solid angle. This efficient technique combines the enhanced sensitivity of a coherent array beamformer with the wide field-of-view seen by an incoherent array beamformer. I will present a special application of this technique, where we use continuum imaging followed by the multi-pixel beamformer to obtain the precise locations of newly discovered MSPs with the GMRT. Accurate positions measured with single observations enable highly sensitive follow-up studies using coherent array beamformer and rapid follow up at higher radio frequencies and other wavelengths. Normally, such accurate positions can only be obtained from a long-term pulsar timing program. The multi-pixel beamformer technique can also be used for highly

  1. EST: The European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Collados, M.

    2008-09-01

    The European Solar Telescope (EST) is a project for a 4 meter-class ground-based telescope, to be located in the Canary Islands. The project is promoted by the European Association for Solar Telescopes (EAST), a consortium formed by research organizations from 15 European countries. EST will be optimized for studies of magnetic coupling between the deep photosphere and upper chromosphere. The project has been approved for funds by the European Union, within the FP-7 framework, to produce the design of all systems and subsystems of the telescope during the next three years. This includes the optical and optomechanical design of the telescope itself and of the instruments and their control. MCAO will be included in the optical path in a natural way to compensate for atmospheric disturbances in an optimum way. The design of EST will strongly emphasize the use of a large number of visible and near-infrared instruments simultaneously which will influence the telescope design from the very beginning. This communication will center mainly on the scientific objectives that EST will address. Generally speaking, they involve understanding how the magnetic field emerges through the solar surface, interacts with the plasma dynamics to transfer energy between different regions, and finally releases it in the form of heat or as violent events in the solar chromosphere and corona. Among the many topics of interest, one may cite, as described in the EST Science Requirements Document: small-scale flux emergence in quiet sun regions, large-scale magnetic structures, magnetic flux cancellation processes, polar magnetic fields, magnetic topology of the photosphere and chromosphere, conversion of mechanical to magnetic energy in the photosphere, wave propagation from photosphere to chromosphere, energy dissipation in the chromosphere at small and large scales, etc. The present status and future perspectives of the project will also be outlined.

  2. Infrared astronomy after IRAS

    NASA Technical Reports Server (NTRS)

    Rieke, G. H.; Thompson, R. I.; Werner, M. W.; Witteborn, F. C.; Becklin, E. E.

    1986-01-01

    The development of infrared astronomy in the wake of IRAS is discussed. Attention is given to an overview of next generation infrared telescope technology, with emphasis on the Space Infrared Telescope Facility (SIRTF) which has been built to replace IRAS in the 1990s. Among the instruments to be included on SIRTF are: a wide-field high-resolution camera covering the infrared range 3-30 microns with large arrays of detectors; an imaging photometer operating in the range 3-700 microns; and a spectrograph covering the range 2.5-200 microns with resolutions of 2 and 0.1 percent. Observational missions for the SIRTF are proposed in connection with: planetary formation; star formation; cosmic energy sources; active galactic nuclei; and quasars.

  3. 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.

  4. Improvements in the data quality of the Interferometric Monitor for Greenhouse Gases.

    PubMed

    Walden, Von P; Tanamachi, Robin L; Rowe, Penny M; Revercomb, Henry E; Tobin, David C; Ackerman, Steven A

    2010-01-20

    The Interferometric Monitor for Greenhouse Gases (IMG) operated aboard the polar-orbiting Advanced Earth Observing Satellite from October 1996 through June 1997. The IMG measured upwelling infrared radiance at fine spectral resolution. This paper identifies previously undocumented issues with IMG interferograms and describes procedures for correcting the majority of the affected data. In particular, single-sided interferograms should be used to avoid large noise bursts, and phase ambiguities must be resolved in uncalibrated spectra before radiometric calibration. The corrections are essential for studies that require accurately calibrated radiance spectra, including those that track atmospheric changes globally on decadal time scales.

  5. CONSTRAINING MASS RATIO AND EXTINCTION IN THE FU ORIONIS BINARY SYSTEM WITH INFRARED INTEGRAL FIELD SPECTROSCOPY

    SciTech Connect

    Pueyo, Laurent; Hillenbrand, Lynne; Hinkley, Sasha; Dekany, Richard; Roberts, Jenny; Vasisht, Gautam; Roberts, Lewis C. Jr.; Shao, Mike; Burruss, Rick; Cady, Eric; Oppenheimer, Ben R.; Brenner, Douglas; Zimmerman, Neil; Monnier, John D.; Crepp, Justin; Parry, Ian; Beichman, Charles; Soummer, Remi

    2012-09-20

    We report low-resolution near-infrared spectroscopic observations of the eruptive star FU Orionis using the Integral Field Spectrograph (IFS) Project 1640 installed at the Palomar Hale telescope. This work focuses on elucidating the nature of the faint source, located 0.''5 south of FU Ori, and identified in 2003 as FU Ori S. We first use our observations in conjunction with published data to demonstrate that the two stars are indeed physically associated and form a true binary pair. We then proceed to extract J- and H-band spectro-photometry using the damped LOCI algorithm, a reduction method tailored for high contrast science with IFS. This is the first communication reporting the high accuracy of this technique, pioneered by the Project 1640 team, on a faint astronomical source. We use our low-resolution near-infrared spectrum in conjunction with 10.2 {mu}m interferometric data to constrain the infrared excess of FU Ori S. We then focus on estimating the bulk physical properties of FU Ori S. Our models lead to estimates of an object heavily reddened, A{sub V} = 8-12, with an effective temperature of {approx}4000-6500 K. Finally, we put these results in the context of the FU Ori N-S system and argue that our analysis provides evidence that FU Ori S might be the more massive component of this binary system.

  6. Interferometric observations of an artificial satellite.

    PubMed

    Preston, R A; Ergas, R; Hinteregger, H F; Knight, C A; Robertson, D S; Shapiro, I I; Whitney, A R; Rogers, A E; Clark, T A

    1972-10-27

    Very-long-baseline interferometric observations of radio signals from the TACSAT synchronous satellite, even though extending over only 7 hours, have enabled an excellent orbit to be deduced. Precision in differenced delay and delay-rate measurements reached 0.15 nanosecond ( approximately 5 centimeters in equivalent differenced distance) and 0.05 picosecond per second ( approximately 0.002 centimeter per second in equivalent differenced velocity), respectively. The results from this initial three-station experiment demonstrate the feasibility of using the method for accurate satellite tracking and for geodesy. Comparisons are made with other techniques.

  7. Millimeter-wave interferometric SAR and polarimetry

    NASA Astrophysics Data System (ADS)

    Boehmsdorff, Stephan; Essen, Helmut; Schimpf, Hartmuf; Wahlen, Alfred

    1998-07-01

    Using synthetic aperture radars with appropriate signal processing algorithms is a recognized technique for remote sensing applications. A wide spectrum of radar frequencies is used and a high degree of sophistication implies polarimetric and further multichannel approaches. Each frequency band used, exhibits special sensitivities to features of the earth's surface or man-made targets. This is mostly due to the coupling of the electromagnetic waves to backscattering geometries which are related to the radarwavelength. A part of the spectrum which has been covered not very intensely is the millimeterwave region. This may be mostly due to the relatively high atmospheric absorption at millimeterwaves which obstructs the use of such sensors for long range applications. On the other hand for military applications IR-imaging sensors are widely used which suffer even more from adverse transmission properties of the atmosphere. Application of multichannel techniques as polarimetry, multifrequency techniques and interferometry are also done with more ease due to compactness of the hardware and simplicity of processing. As there exist no data which would allow to investigate the potential of multifrequency polarimetric and interferometric mmW-SAR the Millimeterwave Experimental Multifrequency Polarimetric High Resolution Interferometric Imaging System was installed into an aircraft C-160 `Transall' to gather respective data over different land scenarios. The off-line evaluation of the radar data starts with off-line track, calibration and reformatting procedures. Afterwards synthetic aperture processing is applied to these data to generate radar images for co- and cross-polarization at 35 GHz and 94 GHz. As already mentioned above, SAR-processing at millimeterwavelengths requires a considerable lower amount of sophistication in comparison with algorithms applied at lower radar-frequencies. This can mainly be attributed to the short aperture length at mm-wave frequencies

  8. Light-pulse atom interferometric device

    DOEpatents

    Biedermann, Grant; McGuinness, Hayden James Evans; Rakholia, Akash; Jau, Yuan-Yu; Schwindt, Peter; Wheeler, David R.

    2016-03-22

    An atomic interferometric device useful, e.g., for measuring acceleration or rotation is provided. The device comprises at least one vapor cell containing a Raman-active chemical species, an optical system, and at least one detector. The optical system is conformed to implement a Raman pulse interferometer in which Raman transitions are stimulated in a warm vapor of the Raman-active chemical species. The detector is conformed to detect changes in the populations of different internal states of atoms that have been irradiated by the optical system.

  9. Speckle Interferometry and Speckle Photometry of Binary Stars at Telescopes of Observatorio Astronomico Nacional

    NASA Astrophysics Data System (ADS)

    Orlov, V.

    The Observatorio Astronomico Nacional (OAN) is a facility of the Instituto de Astronomía of the Universidad Nacional Autónoma de México (IA-UNAM). There are two astronomical sites where the four telescopes are mounted: one site is located at San Pedro Mártir (OAN-SPM), Baja California, and the second one at Tonantzintla (OAN-T), near Puebla, Mexico. These telescopes can be effectively used for speckle interferometric and for speckle photometric measurements of binary and multiple stars with the Rayleigh resolution limit R = 1.22 λ/D. Regular speckle interferometric measurements of binary stars have been made with telescopes of the OAN since 2008. In 2011 we start speckle photometric measurements in three colors (V,R,I). In 2012 two more spectral bands (U,B) were added.

  10. Far Infrared Imaging Spectrometer for Large Aperture Infrared Telescope System

    DTIC Science & Technology

    1985-12-01

    a number of DoD related issues related to Anti-Satellite (ASAT), Space-Based Space Survelliance (SBSS), and Ballistic Missile Defense (BMD...possible using their (1) thermal emission, (2) exhaust, dump and plume spectra, and (3) spatial character- istics and track . 2.2 Cold Target Skin Emission

  11. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2007-01-01

    The scientific capabilities of the James Webb Space Telescope (JWST) fall into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. To enable these four science themes, JWST will be a large (6.6m) cold (50K) telescope launched to the second Earth-Sun Lagrange point early in the next decade. It is the successor to the Hubble Space Telescope, and is a partnership of NASA, ESA and CSA. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In this paper, the status and capabilities of the observatory and instruments in the context of the major scientific goals are reviewed.

  12. System for absolute measurements by interferometric sensors

    NASA Astrophysics Data System (ADS)

    Norton, Douglas A.

    1993-03-01

    The most common problem of interferometric sensors is their inability to measure absolute path imbalance. Presented in this paper is a signal processing system that gives absolute, unambiguous reading of optical path difference for almost any style of interferometric sensor. Key components are a wide band (incoherent) optical source, a polychromator, and FFT electronics. Advantages include no moving parts in the signal processor, no active components at the sensor location, and the use of standard single mode fiber for sensor illumination and signal transmission. Actual absolute path imbalance of the interferometer is determined without using fringe counting or other inferential techniques. The polychromator extracts the interference information that occurs at each discrete wavelength within the spectral band of the optical source. The signal processing consists of analog and digital filtering, Fast Fourier analysis, and a peak detection and interpolation algorithm. This system was originally designed for use in a remote pressure sensing application that employed a totally passive fiber optic interferometer. A performance qualification was made using a Fabry-Perot interferometer and a commercially available laser interferometer to measure the reference displacement.

  13. Digital Detection of Exosomes by Interferometric Imaging

    PubMed Central

    Daaboul, George G.; Gagni, Paola; Benussi, Luisa; Bettotti, Paolo; Ciani, Miriam; Cretich, Marina; Freedman, David S.; Ghidoni, Roberta; Ozkumur, Ayca Yalcin; Piotto, Chiara; Prosperi, Davide; Santini, Benedetta; Ünlü, M. Selim; Chiari, Marcella

    2016-01-01

    Exosomes, which are membranous nanovesicles, are actively released by cells and have been attributed to roles in cell-cell communication, cancer metastasis, and early disease diagnostics. The small size (30–100 nm) along with low refractive index contrast of exosomes makes direct characterization and phenotypical classification very difficult. In this work we present a method based on Single Particle Interferometric Reflectance Imaging Sensor (SP-IRIS) that allows multiplexed phenotyping and digital counting of various populations of individual exosomes (>50 nm) captured on a microarray-based solid phase chip. We demonstrate these characterization concepts using purified exosomes from a HEK 293 cell culture. As a demonstration of clinical utility, we characterize exosomes directly from human cerebrospinal fluid (hCSF). Our interferometric imaging method could capture, from a very small hCSF volume (20 uL), nanoparticles that have a size compatible with exosomes, using antibodies directed against tetraspanins. With this unprecedented capability, we foresee revolutionary implications in the clinical field with improvements in diagnosis and stratification of patients affected by different disorders. PMID:27853258

  14. Model predictions of the results of interferometric observations for stars under conditions of strong gravitational scattering by black holes and wormholes

    SciTech Connect

    Shatskiy, A. A. Kovalev, Yu. Yu.; Novikov, I. D.

    2015-05-15

    The characteristic and distinctive features of the visibility amplitude of interferometric observations for compact objects like stars in the immediate vicinity of the central black hole in our Galaxy are considered. These features are associated with the specifics of strong gravitational scattering of point sources by black holes, wormholes, or black-white holes. The revealed features will help to determine the most important topological characteristics of the central object in our Galaxy: whether this object possesses the properties of only a black hole or also has characteristics unique to wormholes or black-white holes. These studies can be used to interpret the results of optical, infrared, and radio interferometric observations.

  15. Model predictions of the results of interferometric observations for stars under conditions of strong gravitational scattering by black holes and wormholes

    NASA Astrophysics Data System (ADS)

    Shatskiy, A. A.; Kovalev, Yu. Yu.; Novikov, I. D.

    2015-05-01

    The characteristic and distinctive features of the visibility amplitude of interferometric observations for compact objects like stars in the immediate vicinity of the central black hole in our Galaxy are considered. These features are associated with the specifics of strong gravitational scattering of point sources by black holes, wormholes, or black-white holes. The revealed features will help to determine the most important topological characteristics of the central object in our Galaxy: whether this object possesses the properties of only a black hole or also has characteristics unique to wormholes or black-white holes. These studies can be used to interpret the results of optical, infrared, and radio interferometric observations.

  16. Ground based infrared astronomy

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.

    1988-01-01

    Infrared spectroscopic instrumentation has been developed for ground-based measurements of astrophysical objects in the intermediate infrared. A conventional Michelson interferometer is limited for astronomical applications in the intermediate infrared by quantum noise fluctuations in the radiation form the source and/or background incident on the detector, and the multiplex advantage is no longer available. One feasible approach to recovering the multiplex advantage is post-dispersion. The infrared signal after passing through telescope and interferometer, is dispersed by a low resolution grating spectrometer onto an array of detectors. The feasibility of the post-dispersion system has been demonstrated with observations of astrophysical objects in the 5 and 10 micrometer atmospheric windows from ground-based telescopes. During FY87/88 the post-disperser was used at the Kitt Peak 4-meter telescope and McMath telescope with facility Fourier transform spectrometers. Jupiter, Saturn, Mars, and Venus were observed. On Jupiter, the resolution at 12 micrometer was 0.01/cm, considerably higher than had been acheived previously. The spectrum contains Jovian ethane and acetylene emission. Construction was begun on the large cryogenic grating spectrometer.

  17. The DAG project, a 4m class telescope: the telescope main structure performances

    NASA Astrophysics Data System (ADS)

    Marchiori, G.; Busatta, A.; Ghedin, L.; Marcuzzi, E.; Manfrin, C.; Battistel, C.; Pirnay, O.; Flebus, Carlo; Yeşilyaprak, C.; Keskin, O.; Yerli, S.

    2016-07-01

    Dogu Anatolu Gözlemevi (DAG-Eastern Anatolia Observatory) Project is a 4m class optical, near-infrared Telescope and suitable enclosure which will be located at an altitude of 3.170m in Erzurum, Turkey. The DAG telescope is a project fully funded by Turkish Ministry of Development and the Atatürk University of Astrophysics Research Telescope - ATASAM. The Project is being developed by the Belgian company AMOS (project leader), which is also the optics supplier and EIE GROUP, the Telescope Main Structure supplier and responsible for the final site integration. The design of the Telescope Main Structure fits in the EIE TBO Program which aims at developing a Dome/Telescope systemic optimization process for both performances and competitive costs based on previous project commitments like NTT, VLT, VST and ASTRI. The optical Configuration of the DAG Telescope is a Ritchey-Chretien with two Nasmyth foci and a 4m primary thin mirror controlled in shape and position by an Active Optic System. The main characteristics of the Telescope Main Structure are an Altitude-Azimuth light and rigid structure system with Direct Drive Systems for both axis, AZ Hydrostatic Bearing System and Altitude standard bearing system; both axes are equipped with Tape Encoder System. An innovative Control System characterizes the telescope performance.

  18. An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status

    NASA Astrophysics Data System (ADS)

    Matter, A.; Lopez, B.; Antonelli, P.; Lehmitz, M.; Bettonvil, F.; Beckmann, U.; Lagarde, S.; Jaffe, W.; Petrov, R.; Berio, P.; Millour, F.; Robbe-Dubois, S.; Glindemann, A.; Bristow, P.; Schoeller, M.; Lanz, T.; Henning, T.; Weigelt, G.; Heininger, M.; Morel, S.; Cruzalebes, P.; Meisenheimer, K.; Hofferbert, R.; Wolf, S.; Bresson, Y