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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. 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.

  6. The Space Infrared Interferometric Telescope (SPIRIT): A Unique Mission for Exploring the Universe

    NASA Astrophysics Data System (ADS)

    Rinehart, S. A.; SPIRIT Origins Probe Mission Study Team

    2005-12-01

    The Space Infrared Interferometric Telescope (SPIRIT) was selected for study by NASA as a candidate Origins Probe mission. SPIRIT is a two-telescope Michelson interferometer operating over a nominal wavelength range 25 to 400 μ m, and offering a powerful combination of spectroscopy (λ / Δ λ ˜ 3000) and sub-arcsecond angular resolution imaging in a single instrument. With angular resolution two orders of magnitude better than that of the Spitzer Space Telescope, and with comparable sensitivity, SPIRIT will enable us to learn how planetary systems form in protostellar disks, how they acquire their chemical structure, and how they evolve. Further, SPIRIT will be a powerful tool for understanding how the present-day population of galaxies formed and evolved. SPIRIT could be ready to launch as early as 2015.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Note: Near infrared interferometric silicon wafer metrology

    NASA Astrophysics Data System (ADS)

    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.

  12. Broadband infrared beam splitter for spaceborne interferometric infrared sounder.

    PubMed

    Yu, Tianyan; Liu, Dingquan; Qin, Yang

    2014-10-01

    A broadband infrared beam splitter (BS) on ZnSe substrate used for the spaceborne interferometric infrared sounder (SIIRS) is studied in the spectral range of 4.44-15 μm. Both broadband antireflection coating and broadband beam-splitter coating in this BS are designed and tested. To optimize the optical properties and the stability of the BS, suitable infrared materials were selected, and improved deposition techniques were applied. The designed structures matched experimental data well, and the properties of the BS met the application specification of SIIRS. PMID:25322240

  13. Interferometric near-infrared spectroscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    We introduce and implement interferometric near-infrared spectroscopy (iNIRS), which simultaneously extracts the optical and dynamic properties of turbid media from the analysis of the spectral interference fringe pattern. The spectral interference fringe pattern is measured using a Mach-Zehnder interferometer with a frequency swept narrow bandwidth light source such that the temporal intensity autocorrelations can be determined for all photon path lengths. This approach enables time-of-flight (TOF) resolved measurement of scatterer motion, which is a feature inaccessible in well-established diffuse correlation spectroscopy techniques. We prove this by analyzing intensity correlations of the light transmitted through diffusive fluid phantoms with photon random walks of up to 55 (approximately 110 scattering events) using laser sweep rates on the order of 100kHz. Thus, the results we present here advance diffuse optical methods by enabling simultaneous determination of depth-resolved optical properties and dynamics in highly scattering samples.

  14. Optical design of interferometric telescopes with wide fields of view.

    PubMed

    Sabatke, Erin E; Burge, James H; Hinz, Philip

    2006-11-01

    The performance of wide-field multiple-aperture imaging systems is dominated by easily understood, low-order errors. Each aperture produces an individual image, each pair of apertures produces a set of fringes under a diffraction envelope, and the system bandwidth produces a coherence envelope. For wide-field imaging, each of these elements must be coincident in the image plane as the field angle changes. We explore the causes of image degradation, derive first-order rules for preserving image quality across field, and give an example design that enforces some of the rules to achieve a relatively wide-field interferometric imaging telescope. PMID:17068543

  15. AKARI: space infrared cooled telescope

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Salama, Alberto

    2009-12-01

    AKARI, formerly known as ASTRO-F, is the second Japanese space mission to perform infrared astronomical observations. AKARI was launched on 21 February 2006 (UT) and brought into a sun-synchronous polar orbit at an altitude of 700 km by a JAXA M-V rocket. AKARI has a telescope with a primary-mirror aperture size of 685 mm together with two focal-plane instruments on board: the Infrared Camera (IRC), which covers the spectral range 2-26 μm and the Far-Infrared Surveyor (FIS), which operates in the range 50-180 μm. The telescope mirrors are made of sandwich-type silicon carbide, specially developed for AKARI. The focal-plane instruments and the telescope are cooled by a unique cryogenic system that kept the telescope at 6K for 550 days with 180 l super-fluid liquid Helium (LHe) with the help of mechanical coolers on board. Despite the small telescope size, the cold environment and the state-of-the-art detectors enable very sensitive observations at infrared wavelengths. To take advantage of the characteristics of the sun-synchronous polar orbit, AKARI performed an all-sky survey during the LHe holding period in four far-infrared bands with FIS and two mid-infrared bands with IRC, which surpasses the IRAS survey made in 1983 in sensitivity, spatial resolution, and spectral coverage. AKARI also made over 5,000 pointing observations at given targets in the sky for approximately 10 min each, for deep imaging and spectroscopy from 2 to 180 μm during the LHe holding period. The LHe ran out on 26 August 2007, since which date the telescope and instrument are still kept around 40K by the mechanical cooler on board, and near-infrared imaging and spectroscopic observations with IRC are now being continued in pointing mode.

  16. Construction of a Novel Interferometric Array of Small Radio Telescopes

    NASA Astrophysics Data System (ADS)

    Engelhardt, Dalit; Timbie, P.

    2006-12-01

    Interferometric arrays of large numbers of antennas are under study for a variety of programs, such as the Square Kilometer Array and instruments optimized for observing the cosmic microwave background radiation. The Wisconsin Small Telescope Array for Radio-waves (WSTAR) will serve as a test of a simple and inexpensive method for building an adding interferometer with a large number of antennas. The approach creates a simple analog correlator from an ordinary receiver. Signals from each radio antenna are phase-modulated between 0 and 180 degrees at unique frequencies. The signals are added together and then enter a receiver/spectrometer. The visibilities from each baseline are decoded by phase-sensitive detection of the receiver output at the appropriate modulation frequencies. The scheme can be extended to an arbitrary number of antennas and has minimal computational requirements. WSTAR will consist of three small radio telescopes of 2.5 meter diameter which closely follow the Small Radio Telescope (SRT) design developed at the MIT Haystack Observatory. WSTAR will operate as a three-dish adding interferometer of variable spacing. The initial configuration is an equilateral triangle with 10 m spacing. At this stage, one telescope has been successfully constructed and is undergoing initial testing. Completion of the array is expected in 2007. This poster will present the adding algorithm and its significance as well as the construction details of WSTAR. This work was supported by the National Science Foundation's REU program and the Department of Defense's ASSURE program through NSF Award AST-0453442.

  17. Infrared telescope on Spacelab 2

    NASA Technical Reports Server (NTRS)

    Koch, D.

    1979-01-01

    The infrared telescope (IRT) on Spacelab 2 which will be the first cryogenically cooled telescope operated from the Orbiter is discussed. Its objectives are to measure the induced environment about the Orbiter and to demonstrate the ability to manage a large volume of superfluid helium in space. The prime astrophysical objectives are to map extended sources of low surface brightness infrared emission, including the zodiacal light, the galactic plane, and extragalactic regions. The IRT design is described, including the f/4 15.2 cm highly baffled Herschelian telescope cooled to 8 K which may scan to within 35 deg of the sun. The focal plane cooled to 3 K consists of nine discrete photoconductors covering the wavelength of 4.5-120 microns in five bands, with a single stellar detector used for aspect determination. Overlapping scans, contiguous orbits, and a six degree per second scan rate permit rapid redundant coverage of 60 % of the sky.

  18. Space infrared telescope facility project

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.

    1988-01-01

    The functions undertaken during this reporting period were: to inform the planetary science community of the progress and status of the Space Infrared Telescope Facility (SIRTF) Project; to solicit input from the planetary science community on needs and requirements of planetary science in the use of SIRTF at such time that it becomes an operational facility; and a white paper was prepared on the use of the SIRTF for solar system studies.

  19. 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

  20. SIRTF - The Space Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Werner, Michael W.; Eisenhardt, Peter

    1988-01-01

    The complexity and variety of objects in the infrared universe have been revealed by the Infrared Astronomical Satellite (IRAS). Further exploration of this universe will be possible with the Space Infrared Telescope Facility (SIRTF), which offers vast improvements in sensitivity and resolution over IRAS. SIRTF's planned capabilities and current status are briefly reviewed.

  1. Determination of physical properties of the Asteroid (41) Daphne from interferometric observations in the thermal infrared

    NASA Astrophysics Data System (ADS)

    Matter, Alexis; Delbo, Marco; Ligori, Sebastiano; Crouzet, Nicolas; Tanga, Paolo

    2011-09-01

    We describe interferometric observations of the Asteroid (41) Daphne in the thermal infrared obtained with the Mid-Infrared Interferometric Instrument (MIDI) and the Auxiliary Telescopes (ATs) of the European Southern Observatory (ESO) Very Large Telescope Interferometer (VLTI). We derived the size and the surface thermal properties of (41) Daphne by means of a thermophysical model (TPM), which is used for the interpretation of interferometric data for the first time. From our TPM analysis, we derived a volume equivalent diameter for (41) Daphne of 189 km, using a non-convex 3-D shape model derived from optical lightcurves and adaptive optics images (B. Carry, private communication). On the other hand, when using the convex shape of Kaasalainen et al. (Kaasalainen, M., Mottola, S., Fulchignoni, M. [2002]. Icarus 159, 369-395) in our TPM analysis, the resulting volume equivalent diameter of (41) Daphne is between 194 and 209 km, depending on the surface roughness. The shape of the asteroid is used as an a priori information in our TPM analysis. No attempt is made to adjust the shape to the data. Only the size of the asteroid and its thermal parameters such as, albedo, thermal inertia and roughness are adjusted to the data. We estimated our model systematic uncertainty to be of 4% and of 7% on the determination of the asteroid volume equivalent diameter depending on whether the non-convex or the convex shape is used, respectively. In terms of thermal properties, we derived a value of the surface thermal inertia smaller than 50 J m -2 s -0.5 K -1 and preferably in the range between 0 and ˜30 J m -2 s -0.5 K -1. Our TPM analysis also shows that Daphne has a moderate macroscopic surface roughness.

  2. 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.

  3. 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. PMID:16410516

  4. A cooled telescope for infrared balloon astronomy

    NASA Technical Reports Server (NTRS)

    Frederick, C.; Jacobson, M. R.; Harwit, M. O.

    1974-01-01

    The characteristics of a 16 inch liquid helium cooled Cassegrain telescope with vibrating secondary mirror are discussed. The telescope is used in making far infrared astronomical observations. The system houses several different detectors for multicolor photometry. The cooled telescope has a ten to one increase in signal-to-noise ratio over a similar warm version and is installed in a high altitude balloon gondola to obtain data on the H2 region of the galaxy.

  5. 1-meter near-infrared solar telescope

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Xu, J.

    In order to observe the fine structure of solar dynamical field and magnetic field, a 1-meter near-infrared solar telescope was developed by Yunnan Astronomical Observatory, Chinese Academy of Sciences. The telescope is located by the Fuxian Lake in southwest China. In this paper, we will introduce some details of the telescope such as scientific goals, structures, instruments and the parameters of the site. First light observation of high resolution photosphere is introduced too.

  6. 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.

  7. Cooled baffle system for spaceborne infrared telescopes.

    PubMed

    Bock, J J; Lange, A E; Matsuhara, H; Matsumoto, T; Onaka, T; Sato, S

    1995-05-01

    We report the design and testing of a compact system of baffles for cooled infrared telescopes. The baffle system consists of a reflecting forebaffle and a black aftbaffle and provides a high level of rejection of emission from off-axis sources. The forebaffle reflects radiation incident at angles greater than 40° off axis out of the telescope, thereby reducing the aperture heat load. The black aftbaffle absorbs radiation scattered or diffracted by the forebaffle, as well as radiation from sources within 40° off axis. We describe ground-based measurements at λ = 0.9 µm of the baffle system at ambient temperature and rocketborne measurements at far-infrared wavelengths of the baffle system at ~3 K. The effective emissivity of the cooled forebaffle was measured to be 7 × 10(-3). The system has been successfully used in rocketborne measurements of the diffuse infrared background and will be used in the Infrared Telescope in Space. PMID:21037777

  8. 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.

  9. 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.

  10. The Spatial Infrared Imaging Telescope III.

    NASA Astrophysics Data System (ADS)

    Bartschi, B. Y.; Morse, D. E.; Woolston, T. L.

    1996-06-01

    The Spatial Infrared Imaging Telescope III (SPIRIT III) is a mid- through long-wave infrared instrumentation package built and managed by the Space Dynamics Laboratory at Utah State University for the Midcourse Space Experiment. SPIRIT III contains a radiometer and an auto-aligning interferometer-spectrometer that share a telescope designed for high off-axis rejection. A solid-hydrogen cryostat, the first of its kind to be used in a space/satellite application, cools the entire sensor system to cryogenic operating temperatures. This hardware will measure the spectral, spatial, temporal, and intensity characteristics of Earth-limb backgrounds, celestial objects, and other upper atmospheric phenomena. Collected data will provide answers to fundamental questions about Department of Defense surveillance systems and supply invaluable information for system planners and designers of future threat detection systems.

  11. The Infrared Telescope in Space Mission

    NASA Technical Reports Server (NTRS)

    Roellig, Thomas L.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The NASA/Japanese Space Agency Infrared Telescope in Space (IRTS) mission was one of seven experiments on the first Space Flyer Unit (SFU-1). This satellite was launched on a Japanese H-2 expendable launch vehicle from Tanegashima Space Center on March 18, 1995 and was retrieved by the NASA space shuttle the following January for refurbishment and reuse. The IRTS itself consisted of a super-fluid liquid helium-cooled telescope with four infrared focal plane science instruments that operated simultaneously. During its one-month lifetime before the liquid helium was exhausted the IRTS mapped 7% of the sky. These data are now being released to the general astronomical community through IPAC at the California Institute of Technology.

  12. 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.

  13. Cryogenic system for the interferometric cryogenic gravitationalwave telescope, KAGRA - design, fabrication, and performance test -

    NASA Astrophysics Data System (ADS)

    Tokoku, C.; Kimura, N.; Koike, S.; Kume, T.; Sakakibara, Y.; Suzuki, T.; Yamamoto, K.; Chen, D.; Goto, S.; Tanaka, M.; Ioka, S.; Nakamoto, K.; Nezuka, H.; Uchiyama, T.; Ohashi, M.; Kuroda, K.

    2014-01-01

    KAGRA is the cryogenic interferometric gravitational wave telescope designed for the direct detection of gravitational waves from the astronomical sources. To achieve the best sensitivity, one of the most difficult challenges is cooling the mirrors to 20K to reduce the thermal noise. We developed four cryostats and sixteen very-low-vibration cryocooler units to accomplish our purpose. In this paper, we describe the outline of the cryogenic design and fabrication, and the results of the cryogenic performance test of the cryostats and cryocooler units.

  14. Telescope protection algorithm for the Space Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Class, B. F.; Welch, R. V.; Wiltsee, C.

    1988-01-01

    This paper presents a proposed on-board Telescope Protection Algorithm (TPA) for the Space Infrared Telescope Facility (SIRTF). This TPA consists of hardware and software capable of performing both fail-operational and fail-safe modes of operation. In the fail-operational mode, each ephemeris load and slew/dwell command sequence is checked on-board before use. The slew command monitor detects unallowable slew/dwell commands and transfers control to an algorithm which slews to and maintains a safe telescope orientation while preserving precise attitude determination and control. This fail-operational mode is also given the authority to autonomously restart the slew/dwell sequence at a point beyond the faulty command. The fail-safe system consists of software and hardware which detects impending earth, moon, or sun avoidance zone violations and activates a backup hardware safe hold mode. The subject TPA and relevant sensor complement were designed for the SIRTF mission; however, this system can easily be used as a basis for failure detection and correction in a wide range of other missions.

  15. Catadioptric Afocal Telescopes For Scanning Infrared Systems

    NASA Astrophysics Data System (ADS)

    Norrie, David G.

    1986-02-01

    Reflecting and catadioptric lenses have been used in astronomical telescopes for many years. More recently, among other applications, they have been widely used in large-aperture and man-portable image-intensified night vision equipment. The afocal telescope used with a scanning infrared system operating in the 8 to 12µm wave-band is required to match the large field of view and small aperture of the scanner with the small field of view and large entrance aperture required for long-range observation. The telescope construction used is usually a refracting telephoto. This can be configured either as a single field of view lens, as part of a dual or multiple field of view switchable system, or as the basis for a mechanically or optically compensated zoom system. However, for large, high magnification telescopes, catadioptric systems can offer advantages over refractors. Two types of catadioptric lens are described. The first has a "low" magnification (7.5 x ) and utilizes a full aperture germanium lens to correct spherical aberration. The second has a "high" magnification (30 x ) and uses a subaperture germanium element to correct the same aberration.

  16. Spica: the next generation infrared space telescope

    NASA Astrophysics Data System (ADS)

    Goicoechea, J. R.; Nakagawa, T.

    2011-11-01

    We present an overview of SPICA, the Space Infrared Telescope for Cosmology and Astrophysics, a world-class space observatory optimized for mid- and far-IR astronomy (from 5 to ~210 μm) with a cryogenically cooled ~3.2 m telescope (<6 K). Its high spatial resolution and unprecedented sensitivity in both photometry and spectroscopy modes will enable us to address a number of key problems in astronomy. SPICA's large, cold aperture will provide a two order of magnitude sensitivity advantage over current far-IR facilities (λ > 30μm wavelength). In the present design, SPICA will carry mid-IR camera, spectrometers and coronagraph (by JAXA institutes) and a far-IR imager FTS-spectrometer, SAFARI (~34-210 μm, provided by an European/Canadian consortium lead by SRON). Complementary instruments such as a far-IR/submm spectrometer (proposed by NASA) are also being discussed. SPICA will be the only space observatory of its era to bridge the far-IR wavelength gap between JWST and ALMA, and carry out unique science not achievable at visible or submm wavelengths. In this contribution we summarize some of the scientific advances that will be made possible by the large increase in sensitivity compared to previous infrared space missions.

  17. 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

  18. 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.

  19. Control system designs for the shuttle infrared telescope facility

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Parsons, E. K.; Lorell, K. R.

    1979-01-01

    The stringent pointing and stability requirements of the Shuttle Infrared and Telescope Facility (STIRF) are stressed as well as the demands that infrared astronomy and the STIRF in particular place on the design of the pointing system.

  20. Near-infrared interferometric observation of the Herbig Ae star HD 144432 with VLTI/AMBER

    NASA Astrophysics Data System (ADS)

    Chen, L.; Kreplin, A.; Wang, Y.; Weigelt, G.; Hofmann, K.-H.; Kraus, S.; Schertl, D.; Lagarde, S.; Natta, A.; Petrov, R.; Robbe-Dubois, S.; Tatulli, E.

    2012-05-01

    Aims: We study the sub-AU-scale circumstellar environment of the Herbig Ae star HD 144432 with near-infrared VLTI/AMBER observations to investigate the structure of its inner dust disk. Methods: The interferometric observations were carried out with the AMBER instrument in the H and K band. We interpret the measured H- and K-band visibilities, the near- and mid-infrared visibilities from the literature, and the spectral energy distribution (SED) of HD 144432 by using geometric ring models and ring-shaped temperature-gradient disk models with power-law temperature distributions. Results: We derive a K-band ring-fit radius of 0.17 ± 0.01 AU and an H-band radius of 0.18 ± 0.01 AU (for a distance of 145 pc). This measured K-band radius of ~0.17 AU lies in the range between the dust sublimation radius of ~0.13 AU (predicted for a dust sublimation temperature of 1500 K and gray dust) and the prediction of models including backwarming (~0.27 AU). We find that an additional extended halo component is required in both the geometric and temperature-gradient modeling. In the best-fit temperature-gradient model, the disk consists of two components. The inner part of the disk is a thin ring with an inner radius of ~0.21 AU, a temperature of ~1600 K, and a ring thickness ~0.02 AU. The outer part extends from ~1 AU to ~10 AU with an inner temperature of ~400 K. We find that the disk is nearly face-on with an inclination angle of <28°. Conclusions: Our temperature-gradient modeling suggests that the near-infrared excess is dominated by emission from a narrow, bright rim located at the dust sublimation radius, while an extended halo component contributes ~6% to the total flux at 2 μm. The mid-infrared model emission has a two-component structure with ~20% of the flux originating from the inner ring and the rest from the outer parts. This two-component structure is indicative of a disk gap, which is possibly caused by the shadow of a puffed-up inner rim. Based on observations

  1. Infrared detector performance in the Shuttle Infrared Telescope Facility /SIRTF/

    NASA Technical Reports Server (NTRS)

    Mccarthy, S. G.; Autio, G. W.

    1978-01-01

    The limitations imposed on infrared detectors for SIRTF are quite different from those imposed on ground-based, balloon-borne, or aircraft-borne systems. The paper examines the limitations and provides performance predictions corresponding to SIRTF conditions. Detector parameters typical of an infrared camera are used. The detector size is taken to be of the order of the diffraction-limited spot, frequency response is taken to correspond to a fraction of a second or less time constant, and spectral definition is provided by multilayer dielectric filters, inductive or capacitive grids, intrinsic absorption, or a combination of these. A nominal 10-micron bandwidth is assumed. The discussion covers atmospheric absorption and emission, zodiacal dust radiance, Shuttle contaminants, telescope self-emission, charged particle radiation, clear environment detector performance, and trapped radiation effects. It is concluded that the SIRTF design and operating conditions will allow current and near-term state-of-the-art detectors to reach their performance limits with SIRTF at a temperature of 10-12 K.

  2. 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.

  3. 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.

  4. Perspective of imaging in the mid-infrared at the Very Large Telescope Interferometer

    NASA Astrophysics Data System (ADS)

    Lopez, B.; Lagarde, S.; Antonelli, P.; Jaffe, W.; Petrov, R.; Venema, L.; Robbe-Dubois, Sylvie; Bettonvil, F.; Berio, P.; Navarro, R.; Graser, U.; Beckman, U.; Weigelt, G.; Vakili, F.; Henning, T.; Gonzales, J.-C.; Wolf, S.; Bailet, C.; Behrend, J.; Bresson, Y.; Chesneau, O.; Clausse, J. M.; Connot, C.; Dugué, M.; Fantei, Y.; Elswijk, E.; Hanenburg, H.; Hofmann, K. H.; Heininger, M.; ter Horst, R.; Hron, J.; Kragt, J.; Tromp, N.; Agocs, T.; Kroes, G.; Laun, W.; Leinert, Ch.; Lehmitz, M.; Matter, A.; Menut, J. L.; Millour, F.; Neumann, U.; Nussbaum, E.; Ottogalli, S.; Pott, J.-U.; Rigal, F.; Roussel, A.; Schertl, D.; Vannier, M.; Wagner, K.; Mellein, M.; Kroener, T.; Mauclert, N.; Girard, P.; Lagarde, G. M.; Mosoni, L.; Jasko, A.; Glindemann, A.; Phan Duc, T.; Finger, G.; Ives, D.; Jakob, G.; Percheron, I.; Avila, G.; Palsa, R.; Pozna, E.; Lizon, J. L.; Lucuix, Ch.; Menardi, S.; Haguenauer, P.; Gitton, P.; Morel, S.; Gonté, F.; Jolley, P.; Rupprecht, G.; Bourget, P.; Delplancke, F.; Mehrgan, L.; Stegmeier, J.; van Belle, G.; Richichi, A.; Moorwood, A.

    2012-07-01

    MATISSE is a mid-infrared spectro-interferometer combining the beams of up to four Unit Telescopes or Auxiliary Telescopes of the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory. MATISSE will constitute an evolution of the two-beam interferometric instrument MIDI. New characteristics present in MATISSE will give access to the mapping and the distribution of the material, the gas and essentially the dust, in the circumstellar environments by using the mid-infrared band coverage extended to L, M and N spectral bands. The four beam combination of MATISSE provides an efficient uv-coverage: 6 visibility points are measured in one set and 4 closure phase relations which can provide aperture synthesis images in the mid-infrared spectral regime. We give an overview of the instrument including the expected performances and a view of the Science Case. We present how the instrument would be operated. The project involves the collaborations of several agencies and institutes: the Observatoire de la Côte d’Azur of Nice and the INSU-CNRS in Paris, the Max Planck Institut für Astronomie of Heidelberg; the University of Leiden and the NOVA-ASTRON Institute of Dwingeloo, the Max Planck Institut für Radioastronomie of Bonn, the Institut für Theoretische Physik und Astrophysik of Kiel, the Vienna University and the Konkoly Observatory.

  5. Mirror seeing control of large infrared solar telescope

    NASA Astrophysics Data System (ADS)

    Zhang, Haiying; Li, Xinnan; Meng, Xiaohui; Ni, Houkun

    2010-07-01

    To obtain high resolution infrared image, both low photon efficiency and long wavelength of infrared light requires enough large aperture telescope, but large aperture vacuum windows can hardly achieve high optical quality, so open structure becomes the only viable choice for large infrared solar telescope. In addition to the effects of atmospheric turbulence, open solar telescopes suffer from the heating of the optics by sunlight, especially primary mirror heating. These factors cause the image to shiver and become blurred, and increase infrared observing noise. Since blowing air across the front surface of the primary mirror doesn't have the necessary heat transfer coefficient to remove the absorbed heat load, it must be cooled down to maintained at a temperature between 0K and 2K below ambient air temperature to reduce the effects of turbulence. This paper will introduce some cooling methods and simulation results of primary mirror in large infrared solar telescope. On the other hand, mirror material with nice thermal conductivity can reduce the temperature difference between mirror surface and air, and mirror surface polishing at infrared wavelength can be comparatively easier than at visible wavelength, so it is possible to select low cost metal mirror as primary mirror of infrared solar telescope. To analyze the technical feasibility of metal mirror serving as primary mirror, this paper also give some polishing results of aluminum mirror with electroless nickel coating.

  6. Wavefront measurement of space infrared telescopes at cryogenic temperature

    NASA Astrophysics Data System (ADS)

    Kaneda, Hidehiro; Onaka, Takashi; Nakagawa, Takao; Enya, Keigo; Murakami, Hiroshi; Yamashiro, Ryoji; Ezaki, Tatsuhiko; Numao, Yasuyuki; Sugiyama, Yoshikazu

    2005-10-01

    In this paper, we describe our recent activities on wave-front measurement of space infrared telescopes. Optical performance of the 685-mm lightweight telescope on board the Japanese infrared astronomical satellite, ASTRO-F, has been evaluated at cryogenic temperatures. The mirrors of the ASTRO-F telescope are made of sandwich-type silicon carbide (SiC) material, comprising porous core and CVD coat of SiC on the surface. The total wavefront errors of the telescope were measured with an interferometer from outside a liquid-helium chamber; a 75-cm reflecting flat mirror was used for auto-collimating the light from the interferometer. The cryogenic deformation of the flat mirror was derived independently by shifting it in the chamber and its contribution to the wavefront error was removed. In addition to the ASTRO-F telescope, we are currently developing a 3.5-m telescope system for SPICA, the next Japanese infrared astronomical satellite project. Details of our methodology for the ASTRO-F telescope, together with our optical test plan for the SPICA telescope, are reported.

  7. 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.

  8. 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.

  9. Mexican infrared optical new technology telescope (TIM) project

    NASA Astrophysics Data System (ADS)

    Salas, Luis; Ruiz, Elfego; Cruz-Gonzales, Irene; Luna, Esteban; Cuevas, Salvador; Pedrayes, Maria H.; Sierra, Gerardo; Sohn, Erika; Koenigsberger, G.; Valdez, Jorge; Harris, Oswaldo N.; Cobos Duenas, Francisco J.; Tejada, Carlos; Gutierrez, L.; Iriarte, Arturo

    1998-08-01

    We present the Mexican Infrared-Optical New Technology Telescope Project (TIM). The design and construction of a 7.8 m telescope, which will operate at the Observatorio Astronomico Nacional in San Pedro Martir, B.C. (Mexico), are described. The site has been selected based on seeing and sky condition measurements taken for several years. The f/1.5 primary mirror consists of 19 hexagonal off-axis parabolic Zerodur segments. The telescope structure will be alt-az, lightweight, low cost, and high stiffness. It will be supported by hydrostatic bearings. The single secondary will complement a Ritchey-Chretien f/15 design, delivering to Cassegrain focus instrumentation. The telescope will be infrared optimized to allow observations ranging from 0.3 to 20 microns. The TIM mirror cell provides an independent and full active support system for each segment, in order to achieve both, phasing capability and very high quality imaging (0.25 arcsec).

  10. 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.

  11. Performance of HST as an infrared telescope

    NASA Astrophysics Data System (ADS)

    Robberto, Massimo; Sivaramakrishnan, Anand; Bacinski, John J.; Calzetti, Daniela; Krist, John E.; MacKenty, John W.; Piquero, J.; Stiavelli, Massimo

    2000-07-01

    On the basis of the measured NICMOS performance in HST-Cycle 7 and Cycle 7N programs, we analyze the behavior of the HST optical assembly at IR wavelengths. An accurate analysis of the telescope thermal status allows us to estimate the background flux observed by NICMOS, and compare it with the flux actually measured in different filters. The very close match between expected and measured fluxes confirms the validity of our model. A good understanding of the HST emissivity, which turns out to be lower than previous estimates, allows to predict with higher accuracy the performance of the future IR instruments on HST like NICMOS+cooling system and to specify critical design parameters for WFC3. Also, issues related to the long term stability of the system can be addressed more properly, providing useful quantitative insight on future missions such as the Next Generation Space Telescope.

  12. The NASA Infrared Telescope Facility: A Dedicated Telescope for Planetary Astronomy

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    The NASA Infrared Telescope Facility (IRTF) is a dedicated 3.0-m infrared telescope for planetary science. It is located at the summit of Mauna Kea on the island of Hawaii. Important capabilities of the IRTF include: (1) Remote observing from any location, including Europe; (2) Instrument changes during the night can be accommodated; (3) Observing periods as short as one hour can be scheduled; (4) Daytime observing is supported; and (5) Unique instrumentation for planetary science are available. Providing groundbased support of planetary missions is the main objective of this facility.

  13. 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.

  14. 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.

  15. 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.

  16. Progress on the cryogenic system for the KAGRA cryogenic interferometric gravitational wave telescope

    NASA Astrophysics Data System (ADS)

    Sakakibara, Yusuke; Akutsu, Tomotada; Chen, Dan; Khalaidovski, Aleksandr; Kimura, Nobuhiro; Koike, Shigeaki; Kume, Tatsuya; Kuroda, Kazuaki; Suzuki, Toshikazu; Tokoku, Chihiro; Yamamoto, Kazuhiro

    2014-11-01

    KAGRA is a project to construct a cryogenic interferometric gravitational wave detector in Japan. Its mirrors and the lower parts of the suspension systems will be cooled to 20 K in order to reduce thermal noise, one of the fundamental noise sources. One of the key features of KAGRA's cooling system is that it will keep the mirrors cooled without introducing vibration. This paper describes the current status of the design, manufacture and testing of the KAGRA cooling system.

  17. Active control of a 30 m ring interferometric telescope primary mirror.

    PubMed

    Dai, Yichun; Liu, Zhong; Jin, Zhenyu; Xu, Jun; Lin, Jing

    2009-02-01

    The active control of a primary mirror for a ring aperture segmented telescope is different from that of a full aperture segmented telescope. Two active maintenance proposals for the ring telescope designed from the segmented patterns are outlined. We present a preliminary calculation of noise propagation and analysis of primary mirror mode characteristics for each proposal. The modulation transfer functions (MTFs) of the primary mirror corresponding to each maintenance method at several typical working wavelengths are also simulated. PMID:19183591

  18. 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

  19. 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.

  20. 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.

  1. Infrared Photometry for Automated Telescopes: Passband Selection

    NASA Astrophysics Data System (ADS)

    Milone, Gene; Young, Andrew T.

    2011-03-01

    The high precision that photometry in the near and intermediate infrared region can provide has not been achieved, partly because of technical challenges (including cryogenics, which most IR detectors require), and partly because the filters in common use are not optimized to avoid water-vapor absorptions, which are the principal impediment to precise ground-based IR photometry. We review the IRWG filters that achieve this goal, and the trials that were undertaken to demonstrate their superiority. We focus especially on the near IR set and, for high elevation sites, the passbands in the N window. We also discuss the price to be paid for the improved precision, in the form of lower throughput, and why it should be paid: to achieve not only higher precision (i.e., improved signal-to-noise ratio), but also lower extinction, thus producing higher accuracy in extra-atmospheric magnitudes. The edges of the IRWG passbands are not defined by the edges of the atmospheric windows: therefore, they admit no flux from these (constantly varying) edges. The throughput cost and the lack of a large body of data already obtained in these passbands are principal reasons why the IRWG filters are not in wide use at observatories around the world that currently do IR work. Yet a measure of the signal-to-noise ratio varies inversely with both extinction and with a measure of the Forbes effect. So, the small loss of raw throughput is recouped in signal-to-noise gain. We illustrate these points with passbands of both near and intermediate IR passbands. There is also the matter of cost for small production runs of these filters; reduced costs can be realized through bulk orders with uniform filter specifications. As a consequence, the near-IR IRWG passbands offer the prospect of being able to do photometry in those passbands at both high and low elevation sites that are capable of supporting precise photometry, thereby freeing infrared photometry from the need to access exclusively high and

  2. The next-generation infrared space telescope SPICA

    NASA Astrophysics Data System (ADS)

    Nakagawa, Takao; Matsuhara, Hideo; Kawakatsu, Yasuhiro

    2012-09-01

    We present the overview and the current status of SPICA (Space Infrared Telescope for Cosmology and Astrophysics), which is a mission optimized for mid- and far-infrared astronomy with a cryogenically cooled 3.2 m telescope. SPICA has high spatial resolution and unprecedented sensitivity in the mid- and far-infrared, which will enable us to address a number of key problems in present-day astronomy, ranging from the star-formation history of the universe to the formation of planets. To reduce the mass of the whole mission, SPICA will be launched at ambient temperature and cooled down on orbit by mechanical coolers on board with an efficient radiative cooling system, a combination of which allows us to have a 3-m class cooled (6 K) telescope in space with moderate total weight (3.7t). SPICA is proposed as a Japanese-led mission together with extensive international collaboration. ESA's contribution to SPICA has been studied under the framework of the ESA Cosmic Vision. The consortium led by SRON is in charge of a key focal plane instrument SAFARI (SPICA Far-Infrared Instrument). Korea and Taiwan are also important partners for SPICA. US participation to SPICA is under discussion. The SPICA project is now in the "risk mitigation phase". The target launch year of SPICA is 2022.

  3. 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.

  4. Infrared Observations from the New Solar Telescope at Big Bear

    NASA Astrophysics Data System (ADS)

    Goode, Philip R.; Cao, Wenda

    2013-10-01

    The 1.6 m clear aperture solar telescope in Big Bear is operational and with its adaptive optics (AO) system it provides diffraction limited solar imaging and polarimetry in the near-infrared (NIR). While the AO system is being upgraded to provide diffraction limited imaging at bluer wavelengths, the instrumentation and observations are concentrated in the NIR. The New Solar Telescope (NST) operates in campaigns, making it the ideal ground-based telescope to provide complementary/supplementary data to SDO and Hinode. The NST makes photometric observations in Hα (656.3 nm) and TiO (705.6 nm) among other lines. As well, the NST collects vector magnetograms in the 1565 nm lines and is beginning such observations in 1083.0 nm. Here we discuss the relevant NST instruments, including AO, and present some results that are germane to NASA solar missions.

  5. 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.

  6. The Mexican Infrared-Optical New Technology Telescope: TIM Project

    NASA Astrophysics Data System (ADS)

    Cruz-Gonzalez, I.; Salas, L.; Ruiz, E.; Luna, E.; Pedrayes, M.; Sohn, E.; Si Erra, G.; Sanchez, B.; Valdez, J.; Gutierrez, L.; Hiriart, D.; Iriarte, A.

    2001-07-01

    We present the Mexican Infrared-Optical New Technology Telescope Project (TIM). The design and construction of a 7.8 m telescope, which will operate at the Observatorio Astronomico Nacional in San Pedro Martir, B.C. (Mexico), are described. The site has been selected based on seeing and sky condition measurements taken for several years. The f/1.5 primary mirror consists of 19 hexagonal off-axis hyperbolic segments of 1.8 m in diameter. The telescope structure will be alt-az, lightweight, low cost, and high stiffness. It will be supported by hydrostatic bearings. The single secondary will complement a Ritchey-Chretien f/15 design, delivering to Cassegrain focus instrumentation. The telescope will be infrared optimized to allow observations ranging from 0.3 to 20 microns. The TIM mirror cell provides an independent and full active support system for each segment, in order to achieve both, phasing capability and very high quality imaging (0.25 arcsec). The TIM project is one of the most advanced technological UNAM projects. The participation of technical and scientific professionals of other national institutions is crucial for its success. The project is seeking partners and financing.

  7. Prototype Secondary Mirror Assembly For The Space Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

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

    1988-04-01

    We describe our concept for a liquid helium temperature prototype secondary mirror assembly (PSMA) for the Space Infrared Telescope Facility. SIRTF, a NASA "Great Observatory" to be launched in the 1990's, is a superfluid heliumcooled 1-meter class telescope with much more stringent performance requirements than its precursor the Infrared Astronomical Satellite (IRAS). The SIRTF secondary mirror assembly must operate near 4 K and provide the functions of 2-axis dynamic tilting ("chopping") in addition to the conventional functions of focus and centering. The PSMA must be able to withstand random vibration testing and provide all of the functions needed by the SIRTF observatory. Our PSMA concept 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 a unique flexure pivot and a four-actuator control system with feed-back provided by pairs of eddy current position sensors. The actuators are mounted on a second flexure-pivoted mass providing angular momentum compensation 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 AL/L characteristics are nominally identical to that of the aluminum flexure pivot material. The mounting plate is connected to the outer housing by a focus and centering mechanism based upon the six degree of freedom secondary mirror assembly developed for the Hubble Space Telescope.

  8. LINC-NIRVANA for the large binocular telescope: setting up the world's largest near infrared binoculars for astronomy

    NASA Astrophysics Data System (ADS)

    Hofferbert, Ralph; Baumeister, Harald; Bertram, Thomas; Berwein, Jürgen; Bizenberger, Peter; Böhm, Armin; Böhm, Michael; Borelli, José Luis; Brangier, Matthieu; Briegel, Florian; Conrad, Albert; De Bonis, Fulvio; Follert, Roman; Herbst, Tom; Huber, Armin; Kittmann, Frank; Kürster, Martin; Laun, Werner; Mall, Ulrich; Meschke, Daniel; Mohr, Lars; Naranjo, Vianak; Pavlov, Aleksei; Pott, Jörg-Uwe; Rix, Hans-Walter; Rohloff, Ralf-Rainer; Schinnerer, Eva; Storz, Clemens; Trowitzsch, Jan; Yan, Zhaojun; Zhang, Xianyu; Eckart, Andreas; Horrobin, Matthew; Rost, Steffen; Straubmeier, Christian; Wank, Imke; Zuther, Jens; Beckmann, Udo; Connot, Claus; Heininger, Matthias; Hofmann, Karl-Heinz; Kröner, Tim; Nussbaum, Eddy; Schertl, Dieter; Weigelt, Gerd; Bergomi, Maria; Brunelli, Alessandro; Dima, Marco; Farinato, Jacopo; Magrin, Demetrio; Marafatto, Luca; Ragazzoni, Roberto; Viotto, Valentina; Arcidiacono, Carmelo; Bregoli, Giovanni; Ciliegi, Paolo; Cosentino, Guiseppe; Diolaiti, Emiliano; Foppiani, Italo; Lombini, Matteo; Schreiber, Laura; D'Alessio, Francesco; Li Causi, Gianluca; Lorenzetti, Dario; Vitali, Fabrizio; Bertero, Mario; Boccacci, Patrizia; La Camera, Andrea

    2013-08-01

    LINC-NIRVANA (LN) is the near-infrared, Fizeau-type imaging interferometer for the large binocular telescope (LBT) on Mt. Graham, Arizona (elevation of 3267 m). The instrument is currently being built by a consortium of German and Italian institutes under the leadership of the Max Planck Institute for Astronomy in Heidelberg, Germany. It will combine the radiation from both 8.4 m primary mirrors of LBT in such a way that the sensitivity of a 11.9 m telescope and the spatial resolution of a 22.8 m telescope will be obtained within a 10.5×10.5 arcsec scientific field of view. Interferometric fringes of the combined beams are tracked in an oval field with diameters of 1 and 1.5 arcmin. In addition, both incoming beams are individually corrected by LN's multiconjugate adaptive optics system to reduce atmospheric image distortion over a circular field of up to 6 arcmin in diameter. A comprehensive technical overview of the instrument is presented, comprising the detailed design of LN's four major systems for interferometric imaging and fringe tracking, both in the near infrared range of 1 to 2.4 μm, as well as atmospheric turbulence correction at two altitudes, both in the visible range of 0.6 to 0.9 μm. The resulting performance capabilities and a short outlook of some of the major science goals will be presented. In addition, the roadmap for the related assembly, integration, and verification process are discussed. To avoid late interface-related risks, strategies for early hardware as well as software interactions with the telescope have been elaborated. The goal is to ship LN to the LBT in 2014.

  9. 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,

  10. A near-infrared spectrograph for the Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Roe, H. G.; Dunham, E. W.; Bida, T. A.; Hall, J. C.; Degroff, W.

    2011-10-01

    Lowell Observatory is constructing the Discovery Channel Telescope (DCT) at Happy Jack, Arizona, approximately an hour from Lowell's main campus in Flagstaff, Arizona. The DCT is a 4.3-m optical/ infrared telescope. Construction of the telescope is complete and First Light of the DCT is planned for 2012Q2. In its initial configuration instruments will be co-mounted on a rotatable/selectable cube at the Cassegrain focus. Motorized deployable fold mirrors enable rapid switching amongst instruments. In the future the Nasmyth foci will be available for larger instruments as well. The first generation of instruments on DCT include: the Large Monolithic Imager (LMI), the Near-Infrared High-Throughput Spectrograph (NIHTS, pronounced "nights"), and the DeVeny optical spectrograph. The LMI contains a single large 6.1x6.1 K detector with a 12.5 arcmin2 FOV. NIHTS is a low resolution efficient near-infrared spectrograph and is the subject of this presentation. The DeVeny is Lowell's existing optical spectrograph with resolutions available between 500 and 4000. NIHTS is a low-resolution high-throughput infrared spectrograph covering 0.9-2.4 μm in a single fixed spectral setting at a resolution of »100. For simplicity and replicability NIHTS contains no moving parts. The science detector is a 10242 HAWAII-1 array. The fixed slit plate features an 80" long slit with several different slit widths (2,3,4 and 12 pixels) available along its length. The widest slit width is designed to allow accurate flux calibration, while the 3 and 4-pixel slits are closely matched to typical seeing at the DCT site (0.86" mean). Different resolutions will be rapidly selectable by dithering the telescope, and a typical observation is anticipated to involve a sequence of dithers both at the desired resolution and at SED resolution for calibration purposes. Offset guiding and wavefront sensing to control the active optics of the primary mirror are provided by the facility via deployable probes in

  11. Thermal modeling of the Shuttle Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Gier, H. L.; Taylor, W. D.

    1983-01-01

    The Shuttle Infrared Telescope Facility (SIRTF) is a cryogenically cooled telescope in the one-meter aperture class designed for sensing in the infrared from 2-200 microns. This facility is currently planned for multiple missions onboard the Space Shuttle with varying instrument complements. All components of the SIRTF within the field of view of the optics are cryogenically cooled. The baseline primary coolant is supercritical helium which is stored in an external tank and routed through the telescope-cooling the instruments, the optical components and the baffles. For detector cooling below 6 K, small reservoirs of superfluid helium (HeII) are provided. The SIRTF was thermally modeled on the SINDA computer program both for steady state and transient solutions. The analysis shows that the baseline configuration has a large capacity for growth in cryogen requirements. A proportional controller model was developed for transient operations. The control system maintained the optics within all prescribed temperature limits except for certain combinations of transients involving a large step change in the power dissipation in the secondary mirror assembly and/or when the primary mirror was assumed to be constructed of quartz. The baseline SIRTF will perform the mission for which it was designed.

  12. Infrared Doppler instrument for the Subaru Telescope (IRD)

    NASA Astrophysics Data System (ADS)

    Tamura, M.; Suto, H.; Nishikawa, J.; Kotani, T.; Sato, B.; Aoki, W.; Usuda, T.; Kurokawa, T.; Kashiwagi, K.; Nishiyama, S.; Ikeda, Y.; Hall, D.; Hodapp, K.; Hashimoto, J.; Morino, J.; Inoue, S.; Mizuno, Y.; Washizaki, Y.; Tanaka, Y.; Suzuki, S.; Kwon, J.; Suenaga, T.; Oh, D.; Narita, N.; Kokubo, E.; Hayano, Y.; Izumiura, H.; Kambe, E.; Kudo, T.; Kusakabe, N.; Ikoma, M.; Hori, Ya.; Omiya, M.; Genda, H.; Fukui, A.; Fujii, Y.; Guyon, O.; Harakawa, H.; Hayashi, M.; Hidai, M.; Hirano, T.; Kuzuhara, M.; Machida, M.; Matsuo, T.; Nagata, T.; Ohnuki, H.; Ogihara, M.; Oshino, S.; Suzuki, R.; Takami, H.; Takato, N.; Takahashi, Y.; Tachinami, C.; Terada, H.

    2012-09-01

    IRD is the near-infrared high-precision radial velocity instrument for the Subaru 8.2-m telescope. It is a relatively compact (~1m size) spectrometer with a new echelle-grating and Volume-Phase Holographic gratings covering 1-2 micron wavelengths combined with an original frequency comb using optical pulse synthesizer. The spectrometer will employ a 4096x4096-pixel HgCdTe array under testing at IfA, University of Hawaii. Both the telescope/Adaptive Optics and comb beams are fed to the spectrometer via optical fibers, while the instrument is placed at the Nasmyth platform of the Subaru telescope. Expected accuracy of the Doppler-shifted velocity measurements is about 1 m s-1. Helped with the large collecting area and high image quality of the Subaru telescope, IRD can conduct systematic radial velocity surveys of nearby middle-to-late M stars aiming for down to one Earth-mass planet. Systematic observational and theoretical studies of M stars and their planets for the IRD science are also ongoing. We will report the design and preliminary development progresses of the whole and each component of IRD.

  13. NASA Infrared Telescope Facility- The Next 5 Years

    NASA Astrophysics Data System (ADS)

    Tokunaga, A. T.; Bus, S. J.; Tollestrup, E. V.; Rayner, J. T.

    2005-08-01

    The NASA Infrared Telescope Facility (IRTF) is a 3-meter optical/IR telescope dedicated to NASA-related programs of mission support and basic solar system research. All of the funding for IRTF operations comes from the Planetary Astronomy Program. We are preparing the Cooperative Agreement with NASA for the next 5 years (Feb. 2006 -- Jan. 2011). We will strive to refurbish the telescope in order to provide mission support and to allow the IRTF to provide fundamental data for future missions to Mars, comets, satellites, Near-Earth Objects, and asteroids. A major component of our activities will be to improve the image quality of the telescope and to provide high dynamic imaging on the IRTF. Details of our plans can be obtained at: http://irtfweb.ifa.hawaii.edu/Documents/pdf/1_plan_mar04C.pdf We acknowledge the support of NASA Cooperative Agreement no. NCC 5-538 with the National Aeronautics and Space Administration, Planetary Astronomy Program.

  14. Sensitive observations with the Spacelab 2 infrared telescope

    NASA Astrophysics Data System (ADS)

    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.

    The small helium-cooled infrared telescope (Spacelab IRT) is a multiband instrument capable of highly sensitive observations from space. The experiment consists of a cryogenically cooled, very well baffled telescope with a ten channel focal plane array. During the Spacelab 2 flight of the Space Shuttle, this instrument will make observations between 5 and 120 micron wavelength that will be background limited by the expected zodiacal emission. Design considerations necessitated by this level of performance are discussed in this paper. In particular, the operation of a very sensitive focal plane array in the space environment is described. The Spacelab IRT will be used to map the extended, low-surface brightness celestial emission. During the seven day length of the mission better than 70 percent sky coverage is expected. The instrument will also be used to measure the infrared contamination environment of the Space Shuttle. This information will be important in the development of the next generation of infrared astronomical instruments. The performance of the Spacelab IRT, in particular its sensitivity to the contamination environment is detailed.

  15. MIRIS: A Compact Wide-field Infrared Space Telescope

    NASA Astrophysics Data System (ADS)

    Han, Wonyong; Lee, Dae-Hee; Jeong, Woong-Seob; Park, Youngsik; Moon, Bongkon; Park, Sung-Joon; Pyo, Jeonghyun; Kim, Il-Joong; Park, Won-Kee; Lee, Dukhang; Seon, Kwang-Il; Nam, Uk-Won; Cha, Sang-Mok; Park, Kwijong; Park, Jang-Hyun; Yuk, In-Soo; Ree, Chang Hee; Jin, Ho; Choel Yang, Sun; Park, Hong-Young; Shin, Goo-Hwan; Seo, Joung-Ki; Rhee, Seung-Wu; Park, Jong-Oh; Lee, Hyung Mok; Murakami, Hiroshi; Matsumoto, Toshio

    2014-09-01

    A compact infrared space telescope called MIRIS (Multi-purpose Infra-Red Imaging System) was developed by the Korea Astronomy and Space Science Institute (KASI), and launched onboard the Science and Technology Satellite-3 of Korea (STSAT-3) in 2013 November. The main mission of MIRIS is the Paschen-α emission line survey along the Galactic plane and the cosmic infrared background (CIB) observation, particularly around the north ecliptic pole region. For these missions, a wide field of view (3.67 × 3.67°) with an angular resolution of 51.6'' and wavelength coverage from 0.9 ~ 2.0 μm have been adopted for MIRIS, having optical components consisting of a 80 mm main lens and four other lenses with F/2 focal ratio optics. The opto-mechanical system was carefully designed to minimize any effects from shock during the launch process and thermal variation. Also, the telescope was designed to use a passive cooling technique to maintain the temperature around 200 K in order to reduce thermal noise. A micro Stirling cooler was used to cool down the Teledyne PICNIC infrared array to 90 K, which was equipped in a dewar with four filters for infrared passbands of I, H, and Paschen-α and a dual-band continuum line filter. MIRIS system was integrated into the STSAT-3 as its primary payload and successfully passed required tests in the laboratory, such as thermal-vacuum, vibration, and shock tests. MIRIS is now operating in sun synchronous orbits for initial tests and has observed its first images successfully.

  16. 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.

  17. Precision Attitude Determination for an Infrared Space Telescope

    NASA Technical Reports Server (NTRS)

    Benford, Dominic J.

    2008-01-01

    We have developed performance simulations for a precision attitude determination system using a focal plane star tracker on an infrared space telescope. The telescope is being designed for the Destiny mission to measure cosmologically distant supernovae as one of the candidate implementations for the Joint Dark Energy Mission. Repeat observations of the supernovae require attitude control at the level of 0.010 arcseconds (0.05 microradians) during integrations and at repeat intervals up to and over a year. While absolute accuracy is not required, the repoint precision is challenging. We have simulated the performance of a focal plane star tracker in a multidimensional parameter space, including pixel size, read noise, and readout rate. Systematic errors such as proper motion, velocity aberration, and parallax can be measured and compensated out. Our prediction is that a relative attitude determination accuracy of 0.001 to 0.002 arcseconds (0.005 to 0.010 microradians) will be achievable.

  18. Long-range Plans for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Tokunaga, A. T.; Bus, S. J.; Rayner, J.; Tollestrup, E. V.

    2004-11-01

    The NASA Infrared Telescope Facility (IRTF) is a 3-meter optical/IR telescope dedicated to NASA-related programs of mission support and basic solar system research. All of the funding for IRTF operations comes from the Planetary Astronomy Program. The IRTF is unique in providing NASA with a dedicated telescope for mission support. Its aperture is sufficient for many kinds of solar system observations. While large telescopes like the Keck allow astronomers to push the limits of sensitivity, the IRTF provides the ability to carry out complementary studies on brighter objects. In addition, the IRTF provides the planetary community with access to one of the world's best observing sites, the summit of Mauna Kea. The user base of the telescope has been expanding in recent years due to new instrumentation, visible imaging capability, and remote observing. The IRTF also provides opportunities for instrument development and training of students and post-docs, thus helping ensure a solid foundation for the next generation of planetary scientists. A long-range plan is being developed that will position the IRTF to be a powerful facility for mission support well beyond the Cassini mission. A refurbished IRTF would have: (1) Optimized instruments for planetary science that provide high-spectral resolution, wide wavelength coverage, and diffraction-limited imaging capabilities. (2) An adaptive optics system that produces extremely high Strehl ratio images, and includes an extended object wave-front sensor. (3) Focused programs on mission support, NEOs, asteroids, and comets. (4) Remote observing. (5) Rapid response to needs of the planetary community. (6) Flexible scheduling. (7) Daytime observing close to the Sun. We acknowledge the support of NASA Cooperative Agreement no. NCC 5-538 with the National Aeronautics and Space Administration, Planetary Astronomy Program.

  19. The Balloon Experimental Twin Telescope for Infrared Interferometry

    NASA Astrophysics Data System (ADS)

    Rinehart, S. A.; BETTII Team

    2010-10-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe, and Herschel and SOFIA will continue to provide exciting new discoveries. However, the relatively low angular resolution of these missions limits our ability to answer key science questions. Interferometry enables high angular resolution at long wavelengths - a powerful tool for scientific discovery. We will build the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII), and eight-meter baseline Michelson stellar interferometer to fly on a high-altitude balloon. BETTII, using a double-Fourier technique, will simultaneously obtain spatial and spectral information. Further, BETTII will serve as a technological pathfinder for future space-based interferometers such as FKSI, TPF-I, and Darwin.

  20. Contamination control of the SABER cryogenic infrared telescope

    NASA Astrophysics Data System (ADS)

    Dyer, James S.; Brown, Steven; Esplin, Roy W.; Hansen, Galen; Jensen, Scott M.; Stauder, John L.; Zollinger, Lorin

    2002-09-01

    The SABER instrument (Sounding of the Atmosphere using Broadband Emission Spectroscopy) is a cryogenic infrared sensor on the TIMED spacecraft with stringent molecular and particulate contamination control requirements. The sensor measures infrared emissions from atmospheric constituents in the earth limb at altitudes ranging from 60 to 180 km using radiatively-cooled 240 K optics and a mechanically-refrigerated 75 K detector. The stray light performance requirements necessitate nearly pristine foreoptics. The cold detector in a warm sensor presents challenges in controlling the cryodeposition of water and other condensable vapors. Accordingly, SABER incorporates several unique design features and test strategies to control and measure the particulate and molecular contamination environment. These include internal witness mirrors, dedicated purge/depressurization manifolds, labyrinths, cold stops, and validated procedures for bakeout, cooldown, and warmup. The pre-launch and on-orbit contamination control performance for the SABER telescope will be reviewed.

  1. 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.

  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. An Unbiased Near-infrared Interferometric Survey for Hot Exozodiacal Dust

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    Exozodiacal dust is warm or hot dust found in the inner regions of planetary systems orbiting main sequence stars, in or around their habitable zones. The dust can be the most luminous component of extrasolar planetary systems, but predominantly emits in the near- to mid-infrared where it is outshone by the host star. Interferometry provides a unique method of separating this dusty emission from the stellar emission. The visitor instrument PIONIER at the Very Large Telescope Interferometer (VLTI) has been used to search for hot exozodiacal dust around a large sample of nearby main sequence stars. The results of this survey are summarised: 9 out of 85 stars show excess exo- zodiacal emission over the stellar photospheric emission.

  4. 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.

  5. Cryogenic infrared spectrometers and telescopes for the atmosphere: new frontiers

    NASA Astrophysics Data System (ADS)

    Kullmann, Andreas; Riese, Martin; Olschewski, Friedhelm; Stroh, Fred; Grossmann, Klaus-Ulrich

    2004-11-01

    The new airborne CRyogenic Infrared Spectrometers and Telescope for the Atmosphere experiment (CRISTA-New Frontiers) succeeds the CRISTA satellite instrument operated twice during NASA space shuttle flights in November 1994 (STS 66) and August 1997 (STS 85). The first mission of the instrument will take place aboard the high altitude research aircraft M55-Geophysica in a campaign in the tropics in 2005/06. CRISTA-NF is a limb-scanning instrument measuring thermal emissions of various atmospheric trace gases (e.g. water vapor, ozone, chlorofluorocarbons), clouds and aerosols in the mid-infrared spectral region. The incoming radiation entering the optics through a Herschel telescope is analyzed by two Ebert-Fastie grating spectrometers with moderate spectral resolution and finally registered by cryogenic semiconductor-detectors. The optical system is integrated into a compact cryostat which reaches temperatures down to 10K by cooling with supercritical helium. This allows fast measurements and provides good signal-to-noise ratio. A narrow vertical field of view (200m) results in high vertical resolution which is neccessary for the analysis of small scale dynamic processes especially in the upper troposphere and lower stratosphere. This paper gives a scientific motivation, some remarks on the measurement technique and an overview of instrument design and technology.

  6. 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.

  7. 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.

  8. 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

  9. 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

  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. 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.

  12. Lightweighted secondary mirror for the United Kingdom Infrared Telescope

    NASA Astrophysics Data System (ADS)

    Rohloff, Ralf-Rainer; Pitz, Eckhart; Hawarden, Timothy G.; Rees, Nicholas P.; Atad-Ettedgui, Eli; Kaufmann, Horst W.; Schmadel, Lutz

    1999-10-01

    The paper describes the manufacture and testing of a lightweighted Zerodur secondary mirror for the United Kingdom Infrared Telescope on Mauna Kea, Hawaii. The 313 mm diameter mirror is mounted on a Piezo platform for fast tip/tilt corrections. Therefore, the mirror mass has to be minimized to achieve high dynamic properties of the adaptive tip/tilt platform. The goal was to test the convex secondary without large auxiliary optics (Hindle sphere). We measured the mirror through the back surface using a small null lens system. A special transparent and highly homogeneous Zerodur was used for this purpose. We demonstrate that grinding a honeycomb structure and acid-etching of the back side of the mirror does not affect the figure of the polished convex surface.

  13. 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.

  14. 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.

  15. 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.

  16. Infrared telescope design - Implications from cryogenic tests of fused-silica mirrors

    NASA Technical Reports Server (NTRS)

    Melugin, R. K.; Miller, J. H.

    1983-01-01

    A brief review of results from recent cryogenic tests of fused-silica mirrors is given with consideration of the implications for the design of cooled infrared telescopes. Implications include optical performance with a discusion of the top-down optical error budgeting for the Shuttle Infrared Telescope Facility (SIRTF), thermal properties of the mirrors, and mirror mounting.

  17. The Infrared Telescope Facility (IRTF) Spectral Library: Cool Stars

    NASA Astrophysics Data System (ADS)

    Rayner, John T.; Cushing, Michael C.; Vacca, William D.

    2009-12-01

    We present a 0.8-5 μm spectral library of 210 cool stars observed at a resolving power of R ≡ λ/Δλ ~ 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.

  18. Cryogenic telescope on the Infrared Astronomical Satellite (IRAS)

    NASA Astrophysics Data System (ADS)

    Low, F. J.; Beichman, C. A.; Gillett, F. C.; Houck, J. R.; Neugebauer, G.; Langford, D. E.; Walker, R. G.; White, R. H.

    1984-04-01

    The Infrared Astronomical Satellite (IRAS) has completed an unbiased all-sky survey at wavelengths from 10 to 100 microns. The design and performance of the focal plane array is described with emphasis on in-orbit measurements of the sensitivity and stability. In the four broad spectral bands centered at 12, 25, 60, and 100 microns, the system noise equivalent flux density (NEFD) values are in Jy/(Square root of Hz), 0.03, 0.025, 0.046, and 0.21, respectively (Jansky = 10 to the -26th W/sq m/Hz). For point sources, a single scan at the survey rate of 3.8 arcmin/s yields limiting flux densities at the 3-sigma confidence level of 0.36, 0.30, 0.39, and 1.2 Jy. The dc stability of the junction field effect transistor (JFET) amplifiers and the excellent off-axis rejection of the telescope permit total flux measurements of extended infrared emission at levels below 6,000,000 Jy/sr. Response of the extrinsic silicon and germanium photo-detectors to ionizing radiation is described.

  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. Cryogenic silicon carbide mirrors for infrared astronomical telescopes: lessons learnt from AKARI for SPICA

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Kaneda, Hidehiro; Kawada, Mitsunobu; Enya, Keigo; Nakagawa, Takao

    2013-09-01

    Silicon carbide (SiC) has good thermal conductivity, high stiffness, and a relatively low specific density, all of which are advantageous to the application to telescopes operating at cryogenic temperatures. The first Japanese astronomical infrared space mission AKARI, which was launched in 2006 February and completed the second generation all-sky survey at 6 bands from mid- to far-infrared, employed a 700mm cryogenic telescope made of specially developed SiC. It was a sandwich-type of SiC composed of a lightweight porous core and a dense chemical vapor deposition (CVD) coat to decrease the specific density and facilitate machining for achieving the required surface figure accuracy. Measurements with an interferometer of 160-mm sample mirrors demonstrated that the AKARI mirror SiC had good thermal stability down to cryogenic temperatures (~6K), while the mirror support of the compact design became the primary source of the wave-front errors of the AKARI telescope. Taking the advantage of the heritage of the AKARI telescope development as well as ESA's Herschel telescope, we are planning the next infrared space mission SPICA (Space Infrared Telescope for Cosmology and Astrophysics) of a 3.2m cooled telescope in participation of ESA using SiC-based materials. In this presentation, we summarize the development of AKARI SiC telescope and present the development activities of the SPICA telescope from the point of view of SiC being as the mirror material for cryogenic space infrared telescopes.

  1. 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.

  2. 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

  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. Large-area cryocooling for far-infrared telescopes

    NASA Astrophysics Data System (ADS)

    Hoang, Triem T.; O'Connell, Tamara A.; Ku, Jentung; Butler, C. D.; Swanson, Theodore D.

    2003-10-01

    Requirements for cryocooling of large-area heat sources begin to appear in studies of future space missions. Examples are the cooling of (i) the entire structure/mirror of large Far Infrared space telescopes to 4-40K and (ii) cryogenic thermal bus to maintain High Temperature Superconductor electronics to below 75K. The cryocooling system must provide robust/reliable operation and not cause significant vibration to the optical components. But perhaps the most challenging aspect of the system design is the removal of waste heat over a very large area. A cryogenic Loop Heat Pipe (C-LHP)/ cryocooler cooling system was developed with the ultimate goal of meeting the aforementioned requirements. In the proposed cooling concept, the C-LHP collected waste heat from a large-area heat source and then transported it to the cryocooler coldfinger for rejection. A proof-of-concept C-LHP test loop was constructed and performance tested in a vacuum chamber to demonstrate the feasibility of the proposed C-LHP to distribute the cryocooler cooling power over a large area. The test loop was designed to operate with any cryogenic working fluid such as Oxygen/Nitrogen (60-120K), Neon (28-40K), Hydrogen (18-30K), and Helium (2.5-4.5K). Preliminary test results indicated that the test loop had a cooling capacity of 4.2W in the 30-40K temperature range with Neon as the working fluid.

  5. 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

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

    PubMed

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

    2016-01-01

    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. PMID:27193803

  7. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27193803

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

    PubMed

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

    2016-01-11

    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

  10. The (new) Mid-Infrared Spectrometer and Imager (MIRSI) for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Hora, Joseph L.; Trilling, David; Mommert, Michael; Smith, Howard A.; Moskovitz, Nicholas; Marscher, Alan P.; Tokunaga, Alan; Bergknut, Lars; Bonnet, Morgan; Bus, Schelte J.; Connelly, Michael; Rayner, John; Watanabe, Darryl

    2015-11-01

    The Mid-Infrared Spectrometer and Imager (MIRSI) was developed at Boston University and has been in use since 2002 on the Infrared Telescope Facility (IRTF), making observations of asteroids, planets, and comets in the 2 - 25 μm wavelength range. Recently the instrument has been unavailable due to electronics issues and the high cost of supplying liquid helium on Maunakea. We have begun a project to upgrade MIRSI to a cryocooler-based system with new array readout electronics and a dichroic and optical camera to simultaneously image the science field for image acquisition and optical photometry. The mechanical cryocooler will enable MIRSI to be continuously mounted on the IRTF multiple instrument mount (MIM) along with the other facility instruments, making it available to the entire community for multi-wavelength imaging and spectral observations. We will propose to use the refurbished MIRSI to measure the 10 μm flux from Near Earth Objects (NEOs) and determine their diameters and albedos through the use of a thermal model. We plan to observe up to 750 NEOs over the course of a three year survey, most of whose diameters will be under 300 meters. Here we present an overview of the MIRSI upgrade and give the current status of the project.This work is funded by the NASA Solar System Observations/NEOO program.

  11. 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.

  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. System design parameter study for Shuttle Infrared Telescope Facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Mord, A. J.; Bottema, M.; Devereux, W. P.; Poley, R. L.; Strecker, D. W.; Tai, F.

    1983-01-01

    SIRTF is a high-sensitivity, cooled astronomical telescope operating from 2 to 1000 microns. The techniques used in analyzing the sensitivity of the SIRTF system performance to several technical issues are presented. Lowering the telescope temperature to near 4K is found to produce margin in several areas. A refined observing requirements model relieves the hardware performance requirements, and identifies extended source size/observing strategy as an important system specification. Other major conclusions are presented.

  14. Telescope system of the infrared imaging surveyor (IRIS)

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Sugiyama, Yoshikazu; Miura, Shinji

    1998-08-01

    The telescope system of a Japanese IR Astronomical Space Mission, 'IR Imaging Surveyor (IRIS)', is described. The IRIS is a cryogenically-cooled telescope, being planned to be launched in 2003. It will make astronomical observations from near-IR to far-IR regions. The IRIS telescope system is a Ritchey-Chretien type, whose primary mirror size ins 700mm in diameter and whose system F ratio is 6. In order to share the focal plane with two scientific instruments and a focal- plane star sensor, it has a clear field of view of 38 arcminutes in radius. It is being designed to achieve the diffraction-limited performance at 5 micrometers for temperatures below 10K. The IRIS telescope will use light-weight silicon carbide (SiC) mirrors. The current estimate of the primary mirror weight is 9 kg and the goal of total weight of the telescope system is less than 27 kg. Preliminary tests of small size SiC mirrors at 4.2K suggest that slight distortion of the surface figure detected at low temperatures can be reduced by improved CVD processes. The telescope system is designed to meet the launch conditions of the M-V rocket and to have the fundamental frequencies above 100 Hz.

  15. Interferometry with the ESO Very Large Telescope

    NASA Astrophysics Data System (ADS)

    von der Luehe, Oskar; Derie, Frederic; Koehler, Bertrand; Leveque, Samuel A.; Paresce, Francesco; Verola, Massimo

    1997-03-01

    The interferometric mode of the ESO very large telescope (VLT) permits coherent combination of stellar light beams collected by four telescopes with 8 m diameter and by several auxiliary telescopes of the 2 m class. While the position of the 8 m telescopes is fixed, auxiliary telescopes can be moved on rails, and can operate from 30 stations distributed on the top of the observatory site for efficient UV coverage. Coherent beam combination can be achieved with the 8 m telescopes alone, with the auxiliary telescopes alone, or with any combination, up to eight telescopes in total. A distinct feature of the interferometric mode is the high sensitivity due to the 8 m pupil of the main telescopes, with the potential for adaptive optics compensation in the near- infrared spectral regime. The VLT interferometer is conceived as an evolutionary program where a significant fraction of the interferometer's functionality is initially funded, and more capability may be added later while experience is gained and further funding becomes available. The scientific program is now defined by a team which consists of a VLTI scientist at ESO and fifteen astronomers from the VLT community. ESO has recently decided to resume the construction of the VLTI which was delayed in December 1993, in order to achieve first interferometric fringes with two of the 8 m telescopes around the year 2000, and routine operation with 2 m auxiliary telescopes from 2003 onwards. This paper presents an overview of the recent evolution of the project and its future development.

  16. Future technologies for optical and infrared telescopes and instruments

    NASA Astrophysics Data System (ADS)

    Cunningham, Colin

    2009-08-01

    The theme of this conference is the evolution of telescopes over the last 400 years. I present my view on what the major leaps of technology have been, and attempt to predict what new technologies could come along in the next 50 years to change the way we do astronomy and help us make new discoveries. Are we approaching a peak of innovation and discovery, and will this be followed by a slow decline? Or are there prospects for even further technology leaps and consequent new discoveries? Will global resource and financial crises bring an end to our great ambitions, or will we continue with bigger telescopes and more ambitious space observatories?

  17. Image-plane incidence for a baffled infrared telescope

    NASA Astrophysics Data System (ADS)

    Scholl, Marija Strojnik; Padilla, Gonzalo Páez

    1997-03-01

    The on-axis image plane incidence of an extended object (sometimes also called irradiance), radiating as a Lambertian radiator is derived for an optical system with a central obscuration. It is then extended to off-axis image points to obtain a generalized form of image incidence for an extended source. A specific example is provided by the conceptual design proposed for the next generation US IR telescope facility, called SIRTF. An incidence error of 1% is obtained for a telescope with a large baffle around a small secondary mirror. The small error is attributed to the unusually small diameter of the secondary mirror.

  18. Infrared Astronomical Satellite /IRAS/ and Shuttle Infrared Telescope Facility /SIRTF/ - Implications of scientific objectives on focal plane sensitivity requirements

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R.; Walker, R. G.; Witteborn, F. C.

    1978-01-01

    The full potential of infrared astronomy can be realized only through observations made with space-based telescopes cooled to cryogenic temperatures. The paper outlines the scientific mission, system description, and focal plane requirements for two cryogenic telescopes: the Infrared Astronomical Satellite (IRAS) and the Shuttle Infrared Telescope Facility (SIRTF). IRAS, a 60-cm superfluid-helium-cooled telescope system, will perform a one-year 8-120-micron IR sky survey; it will provide results of high reliability and sensitivity, produce the first complete survey data for the 30-120-micron region, and fill in missing portions (spectrally and spatially) of previous surveys short of 30 microns; its focal plane assembly is being designed to approach background-limited performance with an array of 62 discrete detectors. The SIRTF design will allow detailed follow-up studies in the 1-1000-micron range with a 116-160-cm observatory-class instrument. The Shuttle sortie capability introduces the unique SIRTF concept of an easily refurbishable or replaceable focal plane instrument complement in an orbiting cryogenic telescope.

  19. The Design and Capabilities of the EXIST Optical and Infra-Red Telescope (IRT)

    NASA Technical Reports Server (NTRS)

    Kutyrev, A S.; Moseley, S. H.; Golisano, C.; Gong, Q.; Allen, B. T.; Gehrels, N.; Grindlay, J. E.; Hong, J. S.; Woodgate, B. E.

    2010-01-01

    The Infra-Red Telescope is a critical element of the EXIST (Energetic X-Ray Imaging Survey Telescope) observatory. The primary goal of the IRT is to obtain photometric and spectroscopic measurements of high redshift (> or =6) gamma ray reaching to the epoque of reionization. The photometric and spectral capabilities of the IRT will allow to use GRB afterglow as probes of the composition and ionization state of the intergalactic medium of the young universe. 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 in the infrared and optical wavelength, which is particularly valuable at wavelengths unavailable to the ground based observatories. We present the results of the mission study development on the IRT as part of the EXIST observatory. Keywords: infrared spectroscopy, space telescope, gamma ray bursts, early universe

  20. Step-zoom dual-field-of-view infrared telescope

    NASA Astrophysics Data System (ADS)

    Nadeem Akram, Muhammad; Hammad Asghar, Muhammad

    2003-05-01

    The design of a dual-field-of-view telescope for an 8 -12- μm imaging waveband is described. Preliminary calculations are made to determine the first-order parameters of the narrow- and the wide-field modes. To achieve a switchable dual-field-of-view system, one uses an optical configuration based on the axial motion of a single lens group along the optical axis. The same lens is also used for focusing at near objects and for athermalization by small axial movement. A total of six lenses with one conic surface are used in the design, making the telescope cost effective and lightweight. The final optical design is presented, along with the aberrations curves and modulation transfer function plots, showing excellent performance in both fields of view.

  1. Step-zoom dual-field-of-view infrared telescope

    NASA Astrophysics Data System (ADS)

    Akram, Muhammad Nadeem; Asghar, Muhammad Hammad

    2003-05-01

    The design of a dual-field-of-view telescope for an 8-12-μm imaging waveband is described. Preliminary calculations are made to determine the first-order parameters of the narrow- and the wide-field modes. To achieve a switchable dual-field-of-view system, one uses an optical configuration based on the axial motion of a single lens group along the optical axis. The same lens is also used for focusing at near objects and for athermalization by small axial movement. A total of six lenses with one conic surface are used in the design, making the telescope cost effective and lightweight. The final optical design is presented, along with the aberrations curves and modulation transfer function plots, showing excellent performance in both fields of view.

  2. Step-zoom dual-field-of-view infrared telescope.

    PubMed

    Akram, Muhammad Nadeem; Asghar, Muhammad Hammad

    2003-05-01

    The design of a dual-field-of-view telescope for an 8-12-microm imaging waveband is described. Preliminary calculations are made to determine the first-order parameters of the narrow- and the wide-field modes. To achieve a switchable dual-field-of-view system, one use an optical configuration based on the axial motion of a single lens group along the optical axis. The same lens is also used for focusing at near objects and for athermalization by small axial movement. A total of six lenses with one conic surface are used in the design, making the telescope cost effective and lightweight. The final optical design is presented, along with the aberrations curves and modulation transfer function plots, showing excellent performance in both fields of view. PMID:12737462

  3. Automated 1.3-m near-infrared telescope system triggered by gamma-ray burst

    NASA Astrophysics Data System (ADS)

    Murakami, Toshio; Yonetoku, Daisuke; Kinoshita, Shin; Masui, Hiroki; Okuno, Shinya; Yoshinari, Satoru; Kidamura, Takashi; Tanabe, Sachiko; Yokota, Satoshi; Kobayashi, Yukiyasu; Nakagawa, Takao; Nakamura, Takashi

    2006-06-01

    The design for robotic telescopes to observe Gamma-Ray Burst (GRB) afterglows and the results of observations are presented. Quickly fading bright GRB flashes and afterglows provide a good tool to study an extremely early universe. However, most large ground-based telescopes cannot afford to follow-up the afterglows and flashes quickly within a few hours since a GRB explosion. We re-modeled the existing middle-class 1.3 m ø telescope of the near infrared band at ISAS in Japan to match for the above requirement. We also set a small telescope of 30 cm diameter with a conventional CCD. These telescopes can monitor afterglows quickly within a few minutes in J, H, Ks and R band with a grism spectrometer.

  4. 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.

  5. A cryogenically-cooled, balloon-borne far infrared survey telescope

    NASA Technical Reports Server (NTRS)

    Campbell, M. F.

    1979-01-01

    The design and performance of the Arizona cryogenically-cooled, balloon-borne, multiband far infrared survey telescope are described. The 40 cm Cassegrain telescope is completely contained in a liquid helium dewar. The focal plane array consists of Fabry optics and four detectors which each have a 12 arc minute field of view. Both photoconductive and bolometer detectors are utilized at effective wavelengths of 20, 80, 100 and 150 microns. In 1977 the telescope was used to make multicolor large scale maps of 70 square degrees in the Cygnus X region and the W3 region.

  6. 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. PMID:22695670

  7. 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.

  8. Characterization of exoplanet atmospheres using future space-based infrared telescopes: challenges in detecting biomarkers

    NASA Astrophysics Data System (ADS)

    Enya, Keigo

    2014-01-01

    Characterization of exoplanet atmospheres with space-based infrared telescopes is important to detect biomarkers. A promising method is temporary differential observation. For this method, designs of a wideband infrared spectral disperser are presented. A design using a CdTe prism simultaneously covers λ=1-30 μm. Designing binary pupil masks for segmented pupils to be used in spatially resolved observations are also shown for another observational method.

  9. 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.

  10. 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.

  11. Euro50: Proposal for a 50 m Optical and Infrared Telescope

    NASA Astrophysics Data System (ADS)

    Ardeberg, Arne; Andersen, Torben; Rodriguez Espinosa, Jose Miguel

    Staff from Instituto de Astrofisica de Canarias, Lund Observatory, Physics Department and Larmor Research Institute at Galway, and Tuorla Observatory is collaborating on studies for a 50 m optical and infrared telescope. The telescope concepts are based on the work on extremely large telescopes carried out during 1991-2000 at Lund Observatory, and on the experience from the 10.4 m segmented Grantecan telescope presently under construction. The proposed 50 m telescope is a fully adaptive Nasmyth telescope with a Ritchey Chretien configuration. It will have an aspherical, segmented primary mirror with 2 m large segments and a deformable secondary. Adaptive optics will be implemented in several steps. From the beginning, there will be single-conjugate adaptive optics for the K-band. Next, and within the first year of operation, the telescope will have single-conjugate adaptive optics for visible wavelengths. As a third step, and another year of operation, dual-conjugate adaptive optics will be made available for the K-band. The telescope will be housed in a co-rotating enclosure at the Roque de los Muchachos observatory on La Palma. Further studies are in progress aiming at preparation of a proposal during the first half of 2002.

  12. 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.

  13. 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.

  14. The Visible and Infrared Survey Telescope for Astronomy (VISTA): Design, technical overview, and performance

    NASA Astrophysics Data System (ADS)

    Sutherland, Will; Emerson, Jim; Dalton, Gavin; Atad-Ettedgui, Eli; Beard, Steven; Bennett, Richard; Bezawada, Naidu; Born, Andrew; Caldwell, Martin; Clark, Paul; Craig, Simon; Henry, David; Jeffers, Paul; Little, Bryan; McPherson, Alistair; Murray, John; Stewart, Malcolm; Stobie, Brian; Terrett, David; Ward, Kim; Whalley, Martin; Woodhouse, Guy

    2015-03-01

    The Visible and Infrared Survey Telescope for Astronomy (VISTA) is the 4-m wide-field survey telescope at ESO's Paranal Observatory, equipped with the world's largest near-infrared imaging camera (VISTA IR Camera, VIRCAM), with 1.65 degree diameter field of view, and 67 Mpixels giving 0.6 deg2 active pixel area, operating at wavelengths 0.8-2.3 μm. We provide a short history of the project, and an overview of the technical details of the full system including the optical design, mirrors, telescope structure, IR camera, active optics, enclosure and software. The system includes several innovative design features such as the f/1 primary mirror, thedichroic cold-baffle camera design and the sophisticated wavefront sensing system delivering closed-loop 5-axis alignment of the secondary mirror. We conclude with a summary of the delivered performance, and a short overview of the six ESO public surveys in progress on VISTA.

  15. Cryogenic testing of mirrors for infrared space telescopes

    NASA Technical Reports Server (NTRS)

    Miller, J. H.; Witteborn, F. C.; Garland, H. J.

    1982-01-01

    The Shuttle IR Telescope Facility (SIRTF) test apparatus can test candidate mirror materials as large as 66 cm in diameter, at temperatures as low as about 10 K, and is accurate enough to detect optical figure changes as small as a fraction of a wavelength from the room temperature figure. The fused silica mirrors currently undergoing testing in the SIRTF are sunk into a liquid He reservoir with copper straps, whose individual strands are soldered to small silver spots diffused throughout the unfigured side of the mirror to accomplish fast conductive cooling. Optical access to the cold mirror is by means of a small glass port in the vacuum chamber. An interferometer is used to examine the mirror figure throughout the cool-down. Interferograms are photographed, fringe patterns are digitized, and mirror figure contour plots are calculated by means of a computer.

  16. 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.

  17. 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.

  18. Silicon immersion grating spectrograph design for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Tokunaga, A. T.; Bond, T.; Jaffe, D. T.; Mumma, M. J.; Rayner, J. T.; Tollestrup, E. V.; Warren, D. W.

    2008-07-01

    We present a conceptual design for an innovative infrared cross-dispersed spectrograph for the NASA Infrared Telescope Facility (IRTF) at Mauna Kea. This facility-class instrument will provide a resolving power of up to 80,000 at 1.2-2.5 μm and 67,000 at 3-5 μm with a minimum slit width of 0.25". The instrument employs a silicon immersion grating in order to reduce the size of the instrument. The design incorporates a 2048×2048 infrared array for the spectrograph and an infrared slit viewer. The optical design is optimized for the thermal infrared (2.8-5.5 μm).

  19. Large Binocular Telescope Project

    NASA Astrophysics Data System (ADS)

    Hill, John M.; Salinari, Piero

    1998-08-01

    The Large Binocular Telescope (LBT) Project is a collaboration between institutions in Arizona, Germany, Italy, and Ohio. With the addition of the partners from Ohio State and Germany in February 1997, the Large Binocular Telescope Corporation has the funding required to build the full telescope populated with both 8.4 meter optical trans. The first of two 8.4 meter borosilicate honeycomb primary mirrors for LBT was cast at the Steward Observatory Mirror Lab in 1997. The baseline optical configuration of LBT includes adaptive infrared secondaries of a Gregorian design. The F/15 secondaries are undersized to provide a low thermal background focal plane. The interferometric focus combining the light from the two 8.4 meter primaries will reimage the two folded Gregorian focal planes to three central locations. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance were important drivers for the design of the telescope in order to provide the best possible images for interferometric observations. 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 was completed in 1997 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). A series of contracts for the fabrication and machining of the telescope structure had been placed at the end of 1997. The final enclosure design was completed at M3 Engineering & Technology (Tucson), EIE and ADS Italia. During 1997, the telescope pier and the concrete ring wall for the rotating enclosure were completed along with the steel structure of the fixed portion of the enclosure. The erection of the steel structure for the rotating portion of the enclosure will begin in the Spring of 1998.

  20. 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.

  1. NASA-ARC 91.5-cm airborne infrared telescope. [tracking mechanism

    NASA Technical Reports Server (NTRS)

    Mobley, R. E.; Brown, T. M.

    1979-01-01

    A 91.5 cm aperture telescope installed aboard NASA-Lockheed C-141A aircraft for the performance of infrared astronomy is described. A unique feature of the telescope is that its entire structure is supported by a 41 cm spherical air bearing which effectively uncouples it from aircraft angular motion, and with inertial stabilization and star tracking, limits tracking errors to less than 1 arc second in most applications. A general description of the system, a summary of its performance, and a detailed description of an offset tracking mechanism is presented.

  2. The VLTI/PIONIER near-infrared interferometric survey of southern T Tauri stars. I. First results

    NASA Astrophysics Data System (ADS)

    Anthonioz, F.; Ménard, F.; Pinte, C.; Le Bouquin, J.-B.; Benisty, M.; Thi, W.-F.; Absil, O.; Duchêne, G.; Augereau, J.-C.; Berger, J.-P.; Casassus, S.; Duvert, G.; Lazareff, B.; Malbet, F.; Millan-Gabet, R.; Schreiber, M. R.; Traub, W.; Zins, G.

    2015-01-01

    Context. The properties of the inner disks of bright Herbig AeBe stars have been studied with near-infrared (NIR) interferometry and high resolution spectroscopy. The continuum (dust) and a few molecular gas species have been studied close to the central star; however, sensitivity problems limit direct information about the inner disks of the fainter T Tauri stars. Aims: Our aim is to measure some of the properties (inner radius, brightness profile, shape) of the inner regions of circumstellar disk surrounding southern T Tauri stars. Methods: We performed a survey with the VLTI/PIONIER recombiner instrument at H-band of 21 T Tauri stars. The baselines used ranged from 11 m to 129 m, corresponding to a maximum resolution of ~3 mas (~0.45 au at 150 pc). Results: Thirteen disks are resolved well and the visibility curves are fully sampled as a function of baseline in the range 45-130 m for these 13 objects. A simple qualitative examination of visibility profiles allows us to identify a rapid drop-off in the visibilities at short baselines(<10 Mλ) in 8 resolved disks. This is indicative of a significant contribution from an extended (R> 3 au, at 150 pc) contribution of light from the disk. We demonstrate that this component is compatible with scattered light, providing strong support to an earlier prediction. The amplitude of the drop-off and the amount of dust thermal emission changes from source to source suggesting that each disk is different. A by-product of the survey is the identification of a new milli-arcsec separation binary: WW Cha. Spectroscopic and interferometric data of AK Sco have also been fitted with a binary + disk model. Conclusions: The visibility data are reproduced well when thermal emission and scattering from dust are fully considered. The inner radii measured are consistent with the expected dust sublimation radii. The modelling of AK Sco suggests a likely coplanarity between the disk and the binary's orbital plane. Data obtained at the ESO

  3. Internal image motion compensation system for the Shuttle Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Lorell, K. R.; Parsons, E. K.; Powell, J. D.

    1980-01-01

    The Shuttle Infrared Telescope Facility (SIRTF) is being designed as a 1-m, cryogenically cooled telescope capable of a thirty-fold improvement over currently available infrared instruments. The SIRTF, mounted in the Orbiter bay on the Instrument Pointing System (IPS), requires that the image at the focal plane be stabilized to better than 0.1 arcsec with an absolute accuracy of 1 arcsec in order to attain this goal. Current estimates of IPS performance for both stability and accuracy indicate that additional stabilization will be necessary to meet the SIRTF requirements. An Image Motion Compensation (IMC) system, utilizing a Charge Coupled Device (CCD) star tracker located at the focal plane and a steerable mirror in the SIRTF optical path, has been designed to work in conjunction with the IPS.

  4. 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.

  5. Large-Area Reflective Infrared Filters for Millimeter/Sub-mm Telescopes

    NASA Astrophysics Data System (ADS)

    Ahmed, Z.; Grayson, J. A.; Thompson, K. L.; Kuo, C.-L.; Brooks, G.; Pothoven, T.

    2014-09-01

    Ground-based millimeter and sub-millimeter telescopes are attempting to image the sky with ever-larger cryogenically-cooled bolometer arrays, but face challenges in mitigating the infrared loading accompanying large apertures. Absorptive infrared filters supported by mechanical coolers scale insufficiently with aperture size. Reflective metal-mesh filters placed behind the telescope window provide a scalable solution in principle, but have been limited by photolithography constraints to diameters under 300 mm. We present laser etching as an alternate technique to photolithography for fabrication of large-area reflective filters, and show results from lab tests of 500-mm-diameter filters. Filters with up to 700-mm diameter can be fabricated using laser etching with existing capability.

  6. Detectors for the James Webb Space Telescope near-infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Rauscher, Bernard J.; Figer, Donald F.; Regan, Michael W.; Boeker, Torsten; Garnett, James; Hill, Robert J.; Bagnasco, Giorgio; Balleza, Jesus; Barney, Richard; Bergeron, Louis E.; Brambora, Clifford; Connelly, Joe; Derro, Rebecca; DiPirro, Michael J.; Doria-Warner, Christina; Ericsson, Aprille; Glazer, Stuart D.; Greene, Charles; Hall, Donald N.; Jacobson, Shane; Jakobsen, Peter; Johnson, Eric; Johnson, Scott D.; Krebs, Carolyn; Krebs, Danny J.; Lambros, Scott D.; Likins, Blake; Manthripragada, Sridhar; Martineau, Robert J.; Morse, Ernie C.; Moseley, Samuel H.; Mott, D. Brent; Muench, Theo; Park, Hongwoo; Parker, Susan; Polidan, Elizabeth J.; Rashford, Robert; Shakoorzadeh, Kamdin; Sharma, Rajeev; Strada, Paolo; Waczynski, Augustyn; Wen, Yiting; Wong, Selmer; Yagelowich, John; Zuray, Monica

    2004-10-01

    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 λco ~ 5 μm 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.

  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. 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.

  9. 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.

  10. 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.

  11. 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.

  12. An Infrared Optimized AO System for a 15 - 20m Class Telescope

    NASA Astrophysics Data System (ADS)

    Brandl, Bernhard R.; Eikenberry, Stephen S.; Herter, Terry L.; Kulkarni, Jayant

    2003-02-01

    Despite the relatively large number of proposed 'extremely large telescopes' very few of them concentrate on the thermal infrared as their main operating wavelengths. An IR-optimized large telescope located in the Atacama dessert at about 5500m altitude, where many atmospheric windows in the mid-IR open up, would be ideal to study astronomical targets that are either intrinsically red or heavily obscured by dust. A large aperture in the order of 15 - 20m requires adaptive optics correction out to λ<= 20 μm with the least possible thermal emission from the instrument itself. Here we discuss a specialized, integrated AO system that provides diffraction-limited performance in the thermal infrared (at λ>=2.5 μm). This approach is very different from the AO systems proposed for other 10m+ class telescopes. We present the basic concept of such an IR-optimized AO system, based on a 2m chopping adaptive secondary. We derive its technical specifications: configuration, bandwidth, and degrees of freedom show its predicted performance for typical seeing in terms of Strehl ratio as a function of limiting guide star magnitude, wavelength and corrected field-of-view. We also briefly address the science that this AO system/telescope would be ideal for.

  13. The Spitzer South Pole Telescope Deep Field: Survey Design and Infrared Array Camera Catalogs

    NASA Astrophysics Data System (ADS)

    Ashby, M. L. N.; Stanford, S. A.; Brodwin, M.; Gonzalez, A. H.; Martinez-Manso, J.; Bartlett, J. G.; Benson, B. A.; Bleem, L. E.; Crawford, T. M.; Dey, A.; Dressler, A.; Eisenhardt, P. R. M.; Galametz, A.; Jannuzi, B. T.; Marrone, D. P.; Mei, S.; Muzzin, A.; Pacaud, F.; Pierre, M.; Stern, D.; Vieira, J. D.

    2013-12-01

    The Spitzer South Pole Telescope Deep Field (SSDF) is a wide-area survey using Spitzer's Infrared Array Camera (IRAC) to cover 94 deg2 of extragalactic sky, making it the largest IRAC survey completed to date outside the Milky Way midplane. The SSDF is centered at (α, δ) = (23:30, -55:00), in a region that combines observations spanning a broad wavelength range from numerous facilities. These include millimeter imaging from the South Pole Telescope, far-infrared observations from Herschel/SPIRE, X-ray observations from the XMM XXL survey, near-infrared observations from the VISTA Hemisphere Survey, and radio-wavelength imaging from the Australia Telescope Compact Array, in a panchromatic project designed to address major outstanding questions surrounding galaxy clusters and the baryon budget. Here we describe the Spitzer/IRAC observations of the SSDF, including the survey design, observations, processing, source extraction, and publicly available data products. In particular, we present two band-merged catalogs, one for each of the two warm IRAC selection bands. They contain roughly 5.5 and 3.7 million distinct sources, the vast majority of which are galaxies, down to the SSDF 5σ sensitivity limits of 19.0 and 18.2 Vega mag (7.0 and 9.4 μJy) at 3.6 and 4.5 μm, respectively.

  14. 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).

  15. 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.

  16. Cryogenic far-infrared laser absorptivity measurements of the Herschel Space Observatory telescope mirror coatings.

    PubMed

    Fischer, Jacqueline; Klaassen, Tjeerd; Hovenier, Niels; Jakob, Gerd; Poglitsch, Albrecht; Sternberg, Oren

    2004-07-01

    Far-infrared laser calorimetry was used to measure the absorptivity, and thus the emissivity, of aluminum-coated silicon carbide mirror samples produced during the coating qualification run of the Herschel Space Observatory telescope to be launched by the European Space Agency in 2007. The samples were measured at 77 K to simulate the operating temperature of the telescope in its planned orbit about the second Lagrangian point, L2, of the Earth-Sun system. Together, the telescope's equilibrium temperature in space and the emissivity of the mirror surfaces will determine the far-infrared-submillimeter background and thus the sensitivity of two of the three astronomical instruments aboard the observatory if stray-light levels can be kept low relative to the mirror emission. Absorptivities of both clean and dust-contaminated samples were measured at 70, 118, 184, and 496 microm. Theoretical fits to the data predict absorptivities of 0.2-0.4% for the clean sample and 0.2-0.8% for the dusty sample, over the spectral range of the Herschel Space Observatory instruments. PMID:15250543

  17. Aspects of mechanical design for an infrared robotic telescope in Antarctica: IRAIT

    NASA Astrophysics Data System (ADS)

    Di VArano, Igor

    2006-09-01

    The purpose of this thesis is to focus attention on the mechanical aspects in designing an infrared telescope, IRAIT (International Robotic Antarctic Infrared Telescope), with aperture size of 80 cm, f#=21, entirely robotic and remote controlled, which must operate at Dome C, on Antarctic Plateau, starting on Summer 2007. Before illustrating in detail the choice criteria of different mechanical components, in order to satisfy stress requirements and structural verification, and the final design solutions we have adopted,firstly a few tissues must be considered. They mainly concern the preference for Dome C as probably the best observing site in the world, the scientific targets, instruments and tools necessary to reach such goals. The mechanical structure of telescope has been analyzed, and results retrieved by the static and dynamic analysis through a finite element software are illustrated. They concern the behavior of single parts, subassemblies and overall structure to active loads applied. It is shown that, as a matter of fact, thermal stress can be reckoned as the most influent of all static loads. A dynamic analysis of some critical subassemblies was used,in order to determine the frequency response of the system aiming at its best insulation from vibrations.

  18. 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.

  19. Configuration trade-offs for the Space Infrared Telescope Facility pointing control system

    NASA Technical Reports Server (NTRS)

    Pue, A. J.; Strohbehn, K.; Hunt, J. W.

    1985-01-01

    Conceptual pointing control system designs for the Space Infrared Telescope Facility (SIRTF) are examined in terms of fine guidance pointing and large-angle slewing accuracies. In particular, basic trade-offs between body pointing only and body pointing plus image motion compensation (IMC) are considered using a steady-state linear covariance analysis to compute rms pointing errors. It is shown that body pointing can provide good performance during nominal fine pointing but limits the telescope capability to rapidly slew and acquire targets. Overall, body pointing plus IMC would offer superior performance but must be judged against the difficulties posed by the attitude sensor noise and the higher cost and complexity of IMC. It is recommended that improved sensor designs be pursued while slewing performance be enhanced by a combination of an appropriate command profile and control compensation.

  20. 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.

  1. The James Webb Space Telescope's Near-Infrared Camera (NIRCam): Making Models, Building Understanding

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

    Since 2003, the Near Infrared Camear (NIRCam) science team for the James Webb Space Telescope (JWST) has conducted "Train the Trainer" workshops for adult leaders of the Girl Scout of the USA (GSUSA), engaging them in the process of scientific inquiry and equipping them to host astronomy-related activities at the troop level. Training includes topics in basic astronomy (night sky, phases of the Moon, the scale of the Solar System and beyond, stars, galaxies, telescopes, etc.) as well as JWST-specific research areas in extra-solar planetary systems and cosmology, to pave the way for girls and women to understand the first images from JWST. Participants become part of our world-wide network of 160 trainers teaching young women essential STEM-related concepts using astronomy, the night sky environment, applied math, engineering, and critical thinking.

  2. 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.

  3. Design of a new 1-5.5-um infrared camera for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Rayner, John T.; Shure, Mark A.; Toomey, Douglas W.; Onaka, Peter M.; Denault, Anthony J.; Stahlberger, Werner E.; Watanabe, Darryl; Criez, K.; Robertson, L.; Cook, D.; Kidger, Michael J.

    1993-10-01

    The design of a multipurpose 1 - 5.5 micrometers infrared camera (NSFCAM) for the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, is described. The camera is built around the new 256 X 256 InSb array manufactured by Santa Barbara Research Center (SBRC) and incorporates a variety of observing modes to fulfill its role as a major facility instrument. These include three remotely-selectable image scales, a selection of fixed bandpass filters, R equals 50 - 100 spectral resolution circularly variable filters, a grism, coronographic masks, and a polarization imaging capability. Through the use of flexible array clocking schemes, driven by programmable digital signal processors (DSPs), we plan to implement several new operating modes, including real-time shift and add for image stabilization, and fast subarray readouts for occultations. Simultaneous optical and infrared imaging of the same field will be possible through the use of a cold dichroic beamsplitter. This feature is primarily intended for use with the IRTF tip-tilt image stabilization system currently being built. Given a suitable guide star, the camera should achieve near-diffraction limited imaging at 2 - 5 micrometers . In this paper we discuss the design of the optics, cryogenic, electronics and software needed to provide the camera with these capabilities.

  4. 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.

  5. A secondary wobbling mechanism for a balloon-borne infrared telescope

    NASA Astrophysics Data System (ADS)

    Matsuhara, Hideo; Hiromoto, Norihisa; Shibai, Hiroshi; Nakagawa, Takao; Okuda, Haruyuki; Maihara, Toshinori

    1991-11-01

    A wobbling mechanism for a secondary mirror has been developed for a balloon-borne infrared telescope. Friction of the wobbling mechanism is negligibly small, and hence the wobbling mechanism is very reliable for the use in a severe environment at balloon altitudes. Motion is controlled by servo electronics, whose transfer function includes the second-order differential term of the error signal in order to improve the waveform. Good performance of the drive mechanism has been confirmed in two balloon flights in 1988 at an altitude of 31 km.

  6. Estimating the Supernova Cosmological Constraints Possible With the Wide-Field Infrared Survey Telescope

    NASA Astrophysics Data System (ADS)

    Currie, Miles; Rubin, David; Aldering, Greg Scott; Baltay, Charles; Fagrelius, Parker; Law, David R.; Perlmutter, Saul; Pontoppidan, Klaus

    2016-01-01

    The proposed Wide-Field Infrared Survey Telescope (WFIRST) supernova survey will measure precision distances continuously in redshift to 1.7 with excellent systematics control. However, the Science Definition Team report presented a idealized version of the survey, and we now work to add realism. Using SNe from HST programs, we investigate the expected contamination from the host-galaxy light to estimate required exposure times. We also present estimates of purity and completeness, generated by degrading well-measured nearby SN spectra to WFIRST resolution and signal-to-noise. We conclude with a more accurate prediction of the cosmological constraints possible with WFIRST SNe.

  7. 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.

  8. 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.

  9. The Near Infrared Spectrograph on the James Webb Space Telescope: Instrument Overview and User Interface Development

    NASA Astrophysics Data System (ADS)

    Gilbert, Karoline; Beck, Tracy; Karakla, Diane M.; Kassin, Susan; Keyes, Tony; Muzerolle, James; Pavlovsky, Cheryl; Soderblom, David; Ubeda, Leonardo

    2015-08-01

    The Near Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope will provide astronomers the ability to observe through fixed slits, the integral field unit, or in multi-object mode with the micro-shutter array, at spectral resolutions of R ˜ 100, 1000, and 2700. The combination of JWST’s sensitivity and superb resolution in the infrared and NIRSpec’s full wavelength coverage from 0.6 to 5 μm will open new parameter space for studies of galaxies and resolved stellar populations alike. We will provide a general overview of the NIRSpec instrument and the user interface development, including proposal planning and the data calibration and reduction pipeline. We will discuss the capabilities of NIRSpec for survey science, and introduce the science use cases that are being used to drive development of the NIRSpec user interfaces.

  10. 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.

  11. 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.

  12. 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.

    2016-02-01

    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.

  13. Another 5 Years of Operation for the NASA Infrared Telescope Facility

    NASA Astrophysics Data System (ADS)

    Tokunaga, Alan T.; Bus, S. J.; Rayner, J. T.; Tollestrup, E. V.

    2008-09-01

    The 3.0-m NASA Infrared Telescope Facility is funded by the Planetary Astronomy Program and is located near the summit of Mauna Kea. The IRTF was established to obtain solar system observations of interest to NASA. Proposals are accepted twice a year on 01 April and 01 October. A new Cooperative Agreement to operate the IRTF was approved for the time period Feb. 2008 to Jan. 2013. We currently offer a suite of facility instruments that cover the 1--25 μm spectral region, and details can be found at: http://irtfweb.ifa.hawaii.edu/. We offer flexible remote observing that allows convenient access to the telescope with observing blocks as short as one hour. In the coming year we plan to upgrade our moderate resolution spectrograph (SpeX) with a new infrared array as well as to begin work on a high spectral resolution (λ/Δ λ 70,000) cross-dispersed spectrograph for 1--5 μm.

  14. 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.

  15. 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.

  16. Aberration-corrected concave grating for the mid-infrared spectrometer aboard the Infrared Telescope in Space.

    PubMed

    Onaka, T

    1995-02-01

    A mechanically ruled aberration-corrected concave grating was developed for use in the low-resolution mid-infrared spectrometer aboard the cryogenically cooled Infrared Telescope in Space. The design and the performance testing of the grating are reported. The spectrometer requires a wide spectral range (4.5-11.7 µm) and a wide field of view (8 × 8 arcmin) with a low wavelength resolution (Δλ ≤ 0.3 µm). The aberration-corrected concave grating provides a flat focal plane with a small aberration in the spatial direction compared with those caused by the finite size of the entrance slit. It also permits a simple design for the spectrometer, which is advantageous for applications in space cryogenic instruments. The measurements of the wavelength resolution and the spatial resolution are shown to be in good agreement with the predicted performance. The diffraction efficiency of the grating is more than 80% at the blaze wavelength (6 µm) and fairly high (>30%) over the entire wavelength range in question. The grating produces polarization of less than 10% for λ < 6.4 µm and of 10-20% for 6.7 µm <λ 9.7 µm. These results indicate the potential applicability of this type of grating to the wide-field IR spectroscopic observations. PMID:20963166

  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. A near-infrared interferometric survey of debris disc stars. II. CHARA/FLUOR observations of six early-type dwarfs

    NASA Astrophysics Data System (ADS)

    Absil, O.; di Folco, E.; Mérand, A.; Augereau, J.-C.; Coudé du Foresto, V.; Defrère, D.; Kervella, P.; Aufdenberg, J. P.; Desort, M.; Ehrenreich, D.; Lagrange, A.-M.; Montagnier, G.; Olofsson, J.; ten Brummelaar, T. A.; McAlister, H. A.; Sturmann, J.; Sturmann, L.; Turner, N. H.

    2008-09-01

    Aims: We aim at directly detecting the presence of optically thin circumstellar dust emission within the terrestrial planetary zone around main sequence stars known to harbour cold debris discs. The present study focuses on a sample of six bright A- and early F-type stars. Methods: High-precision interferometric observations have been obtained in the near-infrared K band with the FLUOR instrument installed on the CHARA Array. The measured squared visibilities are compared to the expected visibility of the stellar photospheres based on theoretical photospheric models taking into account rotational distortion. We search for potential visibility reduction at short baselines, a direct piece of evidence for resolved circumstellar emission. Results: Our observations bring to light the presence of resolved circumstellar emission around one of the six target stars (ζ Aql) at the 5σ level. The morphology of the emission source cannot be directly constrained because of the sparse spatial frequency sampling of our interferometric data. Using complementary adaptive optics observations and radial velocity measurements, we find that the presence of a low-mass companion is a likely origin for the excess emission. The potential companion is characterised by a K-band contrast of four magnitudes. It has a most probable mass of about 0.6~M⊙ and is expected to orbit between about 5.5 AU and 8 AU from its host star assuming a purely circular orbit. Nevertheless, by adjusting a physical debris disc model to the observed Spectral Energy Distribution of the ζ Aql system, we also show that the presence of hot dust within 10 AU from ζ Aql, producing a total thermal emission equal to 1.69 ± 0.31% of the photospheric flux in the K band, is another viable explanation for the observed near-infrared excess. Our re-interpretation of archival near- to far-infrared photometric measurements shows however that cold dust is not present around ζ Aql at the sensitivity limit of the IRS and MIPS

  19. 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.

  20. Far-infrared BRDFs and reflectance spectra of candidate SOFIA telescope, cavity, and focal-plane instrument surfaces

    NASA Astrophysics Data System (ADS)

    Meyer, Allan W.; Smith, Sheldon M.; Koerber, Christopher T.

    2000-06-01

    The far-infrared reflectance and scattering properties of telescope surfaces, surrounding cavity walls, and surfaces within focal-plane instruments can be significant contributors to background noise. Radiation from sources well off-axis, such as the earth, moon or aircraft engines may be multiply scattered by the cavity walls and/or surface facets of a complex telescope structure. The Non-Specular Reflectometer at NASA Ames Research Center was reactivated and upgraded, and used to measure reflectance and Bi- directional Reflectance Distribution Functions for samples of planned telescope system structural materials and associated surface treatments.

  1. The close environment of high-mass X-ray binaries at high angular resolution. I. VLTI/AMBER and VLTI/PIONIER near-infrared interferometric observations of Vela X-1

    NASA Astrophysics Data System (ADS)

    Choquet, É.; Kervella, P.; Le Bouquin, J.-B.; Mérand, A.; Berger, J.-P.; Haubois, X.; Perrin, G.; Petrucci, P.-O.; Lazareff, B.; Pott, J.-U.

    2014-01-01

    Context. Recent improvements in the sensitivity and spectral resolution of X-ray observations have led to a better understanding of the properties of matter in the near vicinity of high-mass X-ray binaries (HMXB) hosting a supergiant star and a compact object. However, the geometry and physical properties of their environments on larger scales (up to a few stellar radii) are currently only predicted by simulations but have never been directly observed. Aims: We aim to explore the environment of Vela X-1 at a few stellar radii (R⋆) of the supergiant using spatially resolved observations in the near-infrared, and to study its dynamical evolution along the nine-day orbital period of the system. Methods: We observed Vela X-1 in 2010 and 2012 using near-infrared long baseline interferometry at the Very Large Telescope Interferometer (VLTI), respectively with the AMBER instrument in the K band (medium spectral resolution), and the PIONIER instrument in the H band (low spectral resolution). The PIONIER observations span one orbital period to monitor possible evolutions in the geometry of the system. Results: We resolved a structure of 8 ± 3 R⋆ from the AMBER K-band observations, and 2.0-1.2+0.7R* from the PIONIER H-band data. From the closure phase observable, we found that the circumstellar environment of Vela X-1 is symmetrical in the near-infrared. We observed comparable interferometric measurements between the continuum and the spectral lines in the K band, meaning that both emissions originate from the same forming region. From the monitoring of the system over one period in the H band in 2012, we found the signal to be constant with the orbital phase within the error bars. Conclusions: We propose three possible scenarios for this discrepancy between the two measurements: 1) there is a strong temperature gradient in the supergiant wind, leading to a hot component that is much more compact than the cool part of the wind observed in the K band; 2) we observed a

  2. IO:I, a near-infrared camera for the Liverpool Telescope

    NASA Astrophysics Data System (ADS)

    Barnsley, Robert M.; Jermak, Helen E.; Steele, Iain A.; Smith, Robert J.; Bates, Stuart D.; Mottram, Chris J.

    2016-01-01

    IO:I is a new instrument that has recently been commissioned for the Liverpool Telescope, extending current imaging capabilities beyond the optical and into the near-infrared. Cost has been minimized by the use of a previously decommissioned instrument's cryostat as the base for a prototype and retrofitting it with Teledyne's 1.7-μm cutoff Hawaii-2RG HgCdTe detector, SIDECAR ASIC controller, and JADE2 interface card. The mechanical, electronic, and cryogenic aspects of the cryostat retrofitting process will be reviewed together with a description of the software/hardware setup. This is followed by a discussion of the results derived from characterization tests, including measurements of read noise, conversion gain, full well depth, and linearity. The paper closes with a brief overview of the autonomous data reduction process and the presentation of results from photometric testing conducted on on-sky, pipeline processed data.

  3. 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.

  4. 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. PMID:16149339

  5. 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.

  6. Scattering characteristics of Martin Black at 118 microns. [from Infrared Astronomical Satellite telescope baffles

    NASA Technical Reports Server (NTRS)

    Brooks, L. D.; Hubbs, J. E.; Bartell, F. O.; Wolfe, W. L.

    1982-01-01

    BRDF (bidirectional reflectance distribution function) values for 0.000118 m radiation at different angles of incidence and different scattering angles from the Infrared Astronomical Satellite telescope baffle coated with Martin Black are presented. Data from scatterometer experiments are collected and the BRDF and beta - beta sub 0 (sin theta sub s - sin theta sub 0) values are calculated based on the geometry, the voltage readings, the attenuators in the beam, and the calculated reference levels. A composite curve of forward and backward scattering data for several angles of incidence shows a peak near the specular direction (beta - beta sub 0 = 0), which is the instrument profile reduced by the 20% specular reflection of the Martin Black. The nonspecular part of the reflectivity indicates the slightly specular but largely Lambertian character of the coating. Data for the specular reflectivity as a function of the incidence angle unexpectedly shows a decrease in the specular reflectance with increasing angle of incidence.

  7. Robust determination of optical path difference: fringe tracking at the Infrared Optical Telescope Array interferometer

    SciTech Connect

    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 {approx}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 m{sub H}=7.0.

  8. 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.

  9. 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.

  10. A new multi-wavelength solar telescope: Optical and Near-infrared Solar Eruption Tracer (ONSET)

    NASA Astrophysics Data System (ADS)

    Fang, Cheng; Chen, Peng-Fei; Li, Zhen; Ding, Ming-De; Dai, Yu; Zhang, Xiao-Yu; Mao, Wei-Jun; Zhang, Jun-Ping; Li, Ting; Liang, Yong-Jun; Lu, Hai-Tian

    2013-12-01

    A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics & Technology, and the operation is jointly administered with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows: He I 10830 Å, Hα and white-light at 3600 Å and 4250 Å, which are selected in order to simultaneously record the dynamics of the corona, chromosphere and photosphere respectively. Full-disk or partial-disk solar images with a field of 10' at three wavelengths can be obtained nearly simultaneously. It is designed to trace solar eruptions with high spatial and temporal resolutions. This telescope was installed at a new solar observing site near Fuxian Lake in Yunnan Province, southwest China. The site is located at E102N24, with an altitude of 1722 m. The seeing is stable and has high quality. We give a brief description of the scientific objectives and the basic structure of ONSET. Some preliminary results are also presented.

  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. Spectroscopic Capabilities and Possibilities of the Far Infrared and Submillimeter Telescope Mission

    NASA Technical Reports Server (NTRS)

    Pearson, J. C.

    2000-01-01

    The Far Infrared and Submillimeter Telescope (FIRST) mission is the fourth European Space Agency corner stone mission. FIRST will be an observatory with a passively cooled (80 Kelvin) 3.5 meter class telescope and three cryogenic instruments covering the 670 to 80 mm spectral region. The mission is slated for a 4.5 year operational lifetime in an L2 orbit. It will share an Arian 5 launch with PLANCK in early 2007. The three payload instruments include the Spectral and Photometric Imaging Receiver (SPIRE), which is a bolometer array with Martin-Puplett FTS for 200-670 microns, the Photoconductor Array Camera and Spectrometer (PACS), which is a photoconductor array with a grating spectrometer for 80-210 microns and the Heterodyne Instrument for FIRST (HIFI), which is a series of seven heterodyne receivers covering 480-1250 GHz and portions of 1410-1910 GHz and 2400-2700 GHz. FIRST will make many detailed spectral surveys of a wide variety of objects previously obscured by the atmosphere and in regions of the spectrum seldom used for astronomical observations, With all of the spectroscopic capability on FIRST a great deal of laboratory spectroscopic support will be needed for accurate interpretation of the spectral data.

  13. 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.

  14. 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.

  15. 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.

  16. Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA

    NASA Astrophysics Data System (ADS)

    Mizutani, Tadahito; Yamawaki, Toshihiko; Komatsu, Keiji; Goto, Ken; Takeuchi, Shinsuke; Shinozaki, Keisuke; Matsuhara, Hideo; Nakagawa, Takao

    2015-04-01

    The infrared space telescope SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is a next-generation astronomical project of the Japan Aerospace Exploration Agency, which features a 3 m class and 6 K cryogenically cooled space telescope. This paper outlines the current status for the preliminary structural design of the SPICA payload module. Dedicated studies were conducted for key technologies to enhance the design accuracy of the SPICA cryogenic assembly and mitigate the development risk. One of the results is described for the concept of the on-orbit truss separation mechanisms, which aim to both reduce the heat load from the main truss assembly and isolate the microvibration by changing the natural frequency of the spacecraft.

  17. Preliminary structural design and key technology demonstration of cryogenic assembly in the next-generation infrared space telescope SPICA

    NASA Astrophysics Data System (ADS)

    Mizutani, Tadahito; Yamawaki, Toshihiko; Komatsu, Keiji; Goto, Ken; Takeuchi, Shinsuke; Shinozaki, Keisuke

    2014-08-01

    The infrared space telescope SPICA, Space Infrared Telescope for Cosmology and Astrophysics, is a next-generation astronomical project of the Japanese Aerospace Exploration Agency (JAXA), which features a 3m-class and 6K cryogenically- cooled space telescope. This paper outlines the current status for the preliminary structural design of the SPICA payload module. Dedicated studies were conducted for key technologies to enhance the design accuracy of the SPICA cryogenic assembly and mitigate the development risk. One of the results is described in this paper for the concept of the on-orbit truss separation mechanisms, which aim to both reduce the heat load from the main truss assembly and isolate the micro-vibration by changing the natural frequency of the spacecraft.

  18. 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.

  19. Near-Infrared photometry of BOs and Centaurs in support of Spitzer Space Telescope data

    NASA Astrophysics Data System (ADS)

    Pinilla-Alonso, Noemi; Emery, Josh P.; Trilling, David; Mommert, Michael

    2014-08-01

    We propose to measure near-infrared broadband colors of Centaurs and Kuiper Belt objects (KBOs). The proposed ground-based observations will complement 3.6 and 4.5 microns photometry of these bodies obtained with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. Extending reflectances past 2.5 micron with Spitzer enables sensitive searches for absorptions in the 3 to 5 micron region, where relevant species (e.g., complex organics, H2O, CO2, CH4, hydrated silicates) have their fundamental absorption bands. In order to assess the presence of absorptions, however, the Spitzer photometry must be tied to shorter wavelength near-infrared reflectances. Recently, Wright et al. (2012) combined IRAC/Spitzer and NIR colors for a sample of cold KBOs and showed how powerful this technique is detecting the presence of volatiles. In semester 2011B we obtained Gemini NIR data for 12 KBOs (results were presented in the DPS Meeting 2012 and part is included in the Master Dissertation of D. Wright, under the supervision of J.P. Emery). In semester 2011B and 2013A we obtained Gemini NIR data for 12 and 7 KBOs respectively (part of these results were presented in the DPS Meeting 2012 and part is included in the Master Dissertation of D. Wright, under the supervision of J.P. Emery). But our sample is not yet completed and we need more time to complete our study and cover a larger number of targets from our sample of Spitzer data. Approximately 54 objects in our sample that lack NIR colors are visible from GEMINI South in 2014B semester, we propose here to observe 16 of these objects.

  20. 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

  1. 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.

  2. 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.

  3. Direct and interferometric imaging approaches for detecting earth-like extrasolar planets

    NASA Technical Reports Server (NTRS)

    Diner, D. J.; Van Zyl, J.; Jones, D. L.; Tubbs, E.; Wright, V.

    1988-01-01

    This paper discusses functional requirements of space-based observational systems with sufficient sensitivity, resolution, and dynamic range to image earth-like extrasolar planets within a search radius of 10 parsecs from the sun. Both direct and interferometric systems operating at visible and infrared wavelengths are evaluated, and the methods used to establish the system tolerances are presented. Due to the more favorable star/planet contrast ratio in the infrared, optical tolerance requirements are less stringent than in the visible. However, reduction of thermal radiation from the telescope requires cooling of the primary optics. Other tradeoffs between various approaches are enumerated.

  4. 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

  5. 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.

  6. Measuring High-Precision Astrometry with the Infrared Array Camera on the Spitzer Space Telescope

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    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. Based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

  7. 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.

  8. GRAVITY: Microarcsecond Astrometry and Deep Interferometric Imaging with the VLT

    NASA Astrophysics Data System (ADS)

    Eisenhauer, F.; Perrin, G.; Brandner, W.; Straubmeier, C.; Böhm, A.; Baumeister, H.; Cassaing, F.; Clénet, Y.; Dodds-Eden, K.; Eckart, A.; Gendron, E.; Genzel, R.; Gillessen, S.; Gräter, A.; Gueriau, C.; Hamaus, N.; Haubois, X.; Haug, M.; Henning, T.; Hippler, S.; Hofmann, R.; Hormuth, F.; Houairi, K.; Kellner, S.; Kervella, P.; Klein, R.; Kolmeder, J.; Laun, W.; Léna, P.; Lenzen, R.; Marteaud, M.; Naranjo, V.; Neumann, U.; Paumard, T.; Rabien, S.; Ramos, J. R.; Reess, J. M.; Rohloff, R.-R.; Rouan, D.; Rousset, G.; Ruyet, B.; Sevin, A.; Thiel, M.; Ziegleder, J.; Ziegler, D.

    We present the AO assisted, near-infrared VLTI instrument GRAVITY for precision narrow-angle astrometry and interferometric phase referenced imaging of faint objects. With its two fibers per telescope beam, its internal wavefront sensors and fringe tracker, and a novel metrology concept, GRAVITY will not only push the sensitivity far beyond what is offered today, but will also advance the astrometric accuracy for UTs to 10 μas. GRAVITY is designed to work with four telescopes, thus providing phase referenced imaging and astrometry for 6 baselines simultaneously. Its unique capabilities and sensitivity will open a new window for the observation of a wide range of objects, and—amongst others—will allow the study of motions within a few times the event horizon size of the Galactic Center black hole.

  9. Space Telescope Imaging Spectrograph Ultraviolet/Optical Spectroscopy of ``Warm'' Ultraluminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Farrah, D.; Surace, J. A.; Veilleux, S.; Sanders, D. B.; Vacca, W. D.

    2005-06-01

    We present high spatial resolution ultraviolet and optical spectroscopy, obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, of nuclear structures within four ``warm'' ultraluminous infrared galaxies (ULIRGs). We find an active galactic nucleus (AGN) in at least three and probably all four in our sample, hosted in a compact, optically luminous ``knot.'' In three cases these knots were previously identified as a putative AGN from multiband optical imaging. Three objects of the sample also harbor a starburst in one or more knots, suggesting that the optically luminous knots seen in local ULIRGs are the most likely sites of the dust-shrouded starburst and AGN activity that power the infrared emission. The four AGNs have a diverse range of properties: two are classical narrow-line AGNs, one shows both broad and narrow lines and evidence for lines of sight from the narrow- to the broad-line regions, and one is plausibly an FeLoBAL AGN. The probable presence in one object of an FeLoBAL AGN, which are extremely rare in the QSO population, supports the idea that LoBAL AGNs may be youthful systems shrouded in gas and dust rather than AGNs viewed along a certain line of sight. The three starbursts for which detailed constraints are possible show a smaller range in properties; all three bursts are young, with two having ages of ~4 Myr and the third having an age of 20 Myr, suggesting that ULIRGs undergo several bursts of star formation during their lifetimes. None of the starbursts show evidence for initial mass function slopes steeper than about 3.3. The metallicities of the knots for which metallicities can be derived are all at least 1.5 Zsolar. The properties of one further starburst knot are consistent with it being the forming core of an elliptical galaxy. Our results suggest that detailed studies of the knots seen in ULIRGs can give important insights into the most violent starburst and AGN activity at both low and high redshift.

  10. The Space Infrared Telescope for Cosmology and Astrophysics (SPICA) in the New Framework

    NASA Astrophysics Data System (ADS)

    Bradford, Charles; SPICA Consortium, the SAFARI Consortium

    2016-01-01

    SPICA is a cryogenic space-borne observatory designed for optimal sensitivity in the mid-infrared through submillimeter range: 17-230 microns. The mission is an ESA / JAXA collaboration, now considered for the ESA Cosmic Visions M5 opportunity. 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 topics. 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 230 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. SPICA has emerged with a new ESA-JAXA collaborative framework. In the current 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 national agencies led by

  11. Study of the ammonia ice cloud layer in the Equatorial Region of Jupiter from the infrared interferometric experiment on Voyager

    NASA Technical Reports Server (NTRS)

    Marten, A.; Rouan, D.; Baluteau, J. P.; Gautier, D.; Conrath, B. J.; Hanel, R. A.; Kunde, V.; Samuelson, R.; Chedin, A.; Scott, N.

    1981-01-01

    Spectra from the Voyager 1 infrared interferometer spectrometer (IRIS) obtained near the time of closest approach to Jupiter were analyzed for the purpose of inferring ammonia cloud properties associated with the Equatorial Region. Comparisons of observed spectra with synthetic spectra computed from a radiative transfer formulation, that includes multiple scattering, yielded the following conclusions: (1) very few NH3 ice particles with radii less than 3 microns contribute to the cloud opacity; (2) the major source of cloud opacity arises from particles with radii in excess of 30 microns; (3) column particle densities are between 1 and 2 orders of magnitude smaller than those derived from thermochemical considerations alone, implying the presence of important atmospheric motion; and (4) another cloud system is confirmed to exist deeper in the Jovian troposphere.

  12. Spartan infrared camera: high-resolution imaging for the SOAR Telescope

    NASA Astrophysics Data System (ADS)

    Loh, Edwin D.; Biel, Jason D.; Chen, Jian-Jun; Davis, Michael; Laporte, Rene; Loh, Owen Y.

    2004-09-01

    The Spartan Infrared Camera provides tip-tilt corrected imaging for the SOAR Telescope in the 1-2.5μm spectral range with four 2048x2048 HAWAII2 detectors. The median image size is expected to be less than 0.25 arcsec (FWHM), and in the H and K bands a significant amount of the light is expected to be in a core having the diffraction-limited width. The camera has two plate scales: 0.04 arcsec/pixel (f/21) for diffraction-limited sampling in the H and K bands and 0.07 arcsec/pixel (f/12) to cover a 5×5 arcmin2 field, over which tip-tilt correction is substantial. Except for CaF2 field-flattening lenses, the optics is all reflective to achieve the large field size and achromaticity, and all aluminum to match thermally the aluminum cryogenic-optical box in which the optics mount. The Strehl ratio of the camera itself is 0.95-1.00 for the f/21 channel. The optics (including the off-axis aspherical mirrors) will be aligned with precise metrology rather than adjusted using interferometry.

  13. 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.

  14. 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.

  15. 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

  16. Three-element stressed Ge:Ga photoconductor array for the infrared telescope in space.

    PubMed

    Hiromoto, N; Itabe, T; Shibai, H; Matsuhara, H; Nakagawa, T; Okuda, H

    1992-02-01

    A stressed Ge:Ga photoconductor array with three elements applied to the Infrared Telescope in Space satellite was fabricated and tested in experiments at 2.0 K in very low-photon-influx conditions (~ 10(5) photons/s). Stress was applied to three Ge:Ga detectors in a series by a stable and compact stressing apparatus by using cone-disk springs. The cutoff wavelength was ~ 180 microm. Responsivity was ~ 100 A/W, and the product of quantum efficiency and photoconductive gain, etaG, was ~ 1 with a chopping frequency of 2 Hz. The noise equivalent power was <5 x 10(-18) W/Hz((1/2)) when low-noise transimpedance amplifiers were used. A slow transient response and a nonlinear response that was dependent on the background photon influx were observed in the experiments. The latter showed that the etaG had a time constant tau(c) that was proportional to N(ph)(-(1/2)). PMID:20720636

  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. Operation and performance of the mid-infrared camera, NOMIC, on the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Hoffmann, William F.; Hinz, Philip M.; Defrère, Denis; Leisenring, Jarron M.; Skemer, Andrew J.; Arbo, Paul A.; Montoya, Manny; Mennesson, Bertrand

    2014-07-01

    The mid-infrared (8-13 μm) camera, NOMIC, is a critical component of the Large Binocular Telescope Interferometer search for exozodiacal light around near-by stars. It is optimized for nulling interferometry but has general capability for direct imaging, low resolution spectrometry, and Fizeau interferometry. The camera uses a Raytheon 1024x1024 Si:As IBC Aquarius array with a 30 μm pitch which yields 0.018 arc-second pixels on the sky. This provides spatial resolution (λ/D) at a 10 μm wavelength of 0.27 arc-seconds for a single 8.4 meter LBT aperture and of 0.10 arcseconds for Fizeau interferometry with the dual apertures. The array is operated with a differential preamplifier and a version of the 16 channel array controller developed at Cornell University for the FORCAST instrument on the Sofia Observatory. With a 2.4 MHz pixel rate the camera can achieve integration times as short as 27 milliseconds full array and 3 milliseconds partial array. The large range of integration times and two array integration well sizes allow for a wide range of background flux on the array. We describe the design and operation of the camera and present the performance of this system in terms of linearity, noise, quantum efficiency, image quality, and photometric sensitivity.

  19. A contamination control cover for the Mid Infrared Instrument of the James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Glauser, Adrian M.; Langer, Ulrich; Zehnder, Alex; Güdel, Manuel

    2008-07-01

    During its cold mission phase at 7 Κ the Mid Infrared Instrument (MIRI) is the coldest spot on the James Webb Space Telescope (JWST) and will act consequently as a cryopump of the instrument's environment. Since the absorption of outgassing molecules from the spacecraft (mainly water and hydrocarbons) on optical surfaces would lead to a significant degradation of the optical performance of MIRI, a Contamination Control Cover (CCC) has been introduced. This cover is placed in the entrance optical path of MIRI right after the picko. mirror (POM) and will be closed during the instrument's cool down phase and at MIRI's operational temperature each time the POM is heated up for decontamination. The CCC will be used further as an optical shutter for dark sky calibration and for the protection against latency images which might emerge from coronagraphic filter changes. Therefore, the CCC has been designed to be multi operational with approximately 3000 life cycles. A contact-free labyrinth seal allows the required reduction of molecular flow towards the instrument and avoids the possibility of any freezing. The CCC is operational between 300 Κ and 7 Κ and is actuated by two redundant stepper motors. In this paper we describe the design of the CCC and the results of the qualification campaign. Further a dedicated measurement of its molecular conductance at various temperatures is presented.

  20. Optical/infrared views of the distant universe with ground-based telescopes

    NASA Astrophysics Data System (ADS)

    Gallagher, J. S.; Tolstoy, E.

    1997-05-01

    Ground-based optical/IR observatories offer access to the rest frame ultraviolet and visible spectral regions of objects with high redshifts. Current observations of high redshift objects with natural seeing of 0.5-1 arcsec include optical/IR photometry and a variety of spectroscopic measurements. These take advantage of the large apertures and efficient instruments of ground-based observatories to obtain high spectral resolution and to reach low surface brightnesses, which is required to overcome cosmological effects. The success of natural guide star adaptive optics systems suggests that observations could become routine with image diameters <=0.25 arcsec (and often approaching 0.1 arcsec) over modest fields of view in the IJHK bands. The combination of adaptive optics on 8-10-m class telescopes, versatile arrays of powerful instruments (including multi-slit or integral field unit spectrographs), and airglow suppression schemes will support deeper and more intensive infrared investigations of faint galaxies, and will allow us to take advantage of increased brightness in strong emission lines. This work should lead to a better understanding of selection effects at high redshift, as well as the identification and measurement of internal properties for typical galaxies at early epochs.

  1. 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.

  2. 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).

  3. The Adaptive Optics System for the New 6.5 Meter MMT Optical/Infrared Telescope

    NASA Astrophysics Data System (ADS)

    McGuire, Patrick C.; Lloyd-Hart, Michael; Angel, J. Roger P.; Angeli, George Z.; Johnson, Robert L.; Fitz-Patrick, Bruce C.; Davison, Warren B.; Sarlot, Roland J.; Bresloff, Cyndy J.; Hughes, John M.; Miller, Steve M.; Schaller, Phillip; Wildi, Francois P.; Kenworthy, Matthew A.; Cordova, Richard M.; Rademacher, Matthew L.; Rascon, Mario H.; Langlois, Maud; Roberts, Thomas; McCarthy, Don; Burge, James H.; Rhoadarmer, Troy A.; Shelton, J. Christopher; Jacobsen, Bruce; Salinari, Piero; Brusa, Guido; Del Vecchio, Ciro; Biasi, Roberto; Gallieni, Daniele; Sandler, David G.; Barrett, Todd K.

    1999-10-01

    The Multiple Mirror Telescope (MMT) is currently being upgraded to a single 6.5 meter diameter mirror and should see first light at prime focus in September 1999. We are constructing an F/15 adaptive optics (AO) system which will be an integral part of the new MMT with first light in early 2000, removing the effect of atmospheric turbulence so that images near the diffraction limit in the near-infrared can be achieved. The deformable element of this system is a 64 cm diameter secondary mirror composed of a 1.8 mm thick thin glass shell and 336 voice coil actuators operating at 1 kHz. This is the first system that uses the secondary mirror as the correcting element, which means thermal background is minimized. We will primarily present an overview of the adaptive optics technique, followed by select results which will include the laboratory testing of the AO system components with a solid secondary, data taken with the wavefront sensor camera at prime focus of the new MMT, and tests of the secondary mirror control system.

  4. 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

    2016-07-01

    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.

  5. 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.

  6. INTERFEROGRAM-BASED INFRARED SEARCH SYSTEM

    EPA Science Inventory

    A computerized search routine for the identification of infrared spectra using interferometric data exclusively is described. Two forms of instrument-dependent information present in raw interferometric data are removed prior to the search process. Interferometric phase error is ...

  7. The Infrared Telescope Facility (IRTF) spectral library:. Spectral diagnostics for cool stars

    NASA Astrophysics Data System (ADS)

    Cesetti, M.; Pizzella, A.; Ivanov, V. D.; Morelli, L.; Corsini, E. M.; Dalla Bontà, E.

    2013-01-01

    Context. The near-infrared (NIR) wavelength range offers some unique spectral features, and it is less prone to the extinction than the optical one. Recently, the first flux calibrated NIR library of cool stars from the NASA Infrared Telescope Facility (IRTF) have become available, and it has not been fully exploited yet. Aims: We want to develop spectroscopic diagnostics for stellar physical parameters based on features in the wavelength range 1-5 μm. In this work we test the technique in the I and K bands. The study of the Y, J, H, and L bands will be presented in the following paper. Methods: An objective method for semi-empirical definition of spectral features sensitive to various physical parameters is applied to the spectra. It is based on sensitivity map - i.e., derivative of the flux in the spectra with respect to the stellar parameters at a fixed wavelength. New optimized indices are defined and their equivalent widths (EWs) are measured. Results: The method is applied in the I- and K-band windows of the IRTF stellar spectra to verify the new technique by comparing the results with the known behavior of well-studied spectral features. A number of sensitive features to the effective temperature and surface gravity are re-identified or newly identified clearly showing the reliability of the sensitivity map analysis. Conclusions: The sensitivity map allows to identify the best bandpass limits for the line and nearby continuum. It reliably predicts the trends of spectral features with respect to a given physical parameter but not their absolute strengths. Line blends are easy to recognize when blended features have different behavior with respect to some physical stellar parameter. The use of sensitivity map is therefore complementary to the use of indices. We give the EWs of the new indices measured for the IRTF star sample. This new and homogeneous set of EWs will be useful for stellar population synthesis models and can be used to get element

  8. 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.

  9. 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).

  10. 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.

  11. 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.

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

    SciTech Connect

    Shorthill, R.W.

    1990-04-01

    An infrared (I.R.) optics package designed for a I.R. detector calibration survey will be used in conjunction with the 90 inch telescope at the University of Wyoming, or as a portable, stand along unit. An important part of this instrument package is a mechanical light beam chopper which rotates with a fixed phase relation with respect to a wobbling secondary mirror in the telescope. A control circuit synchronizes the chopper to an external signal when used at the Wyoming site, or generates an internal reference frequency when used as a portable system. The portable system consists of a small equatorial telescope mount to support the same I.R. instrumentation package, which is used without additional optics. An automated positioning and tracking system encorporates a personal computer to control the environment of the telescope mount via stepper motors attached to the drive axis. The computer is also used to record all data on floppy disc for both fixed and portable systems.

  13. The potential for detecting gamma-ray burst afterglows from population III stars with the next generation of infrared telescopes

    SciTech Connect

    Macpherson, D.; Coward, D. M.; Zadnik, M. G.

    2013-12-10

    We investigate the detectability of a proposed population of gamma-ray bursts (GRBs) from the collapse of Population III (Pop III) stars. The James Webb Space Telescope (JWST) and Space Infrared Telescope for Cosmology and Astrophysics (SPICA) will be able to observe the late time infrared afterglows. We have developed a new method to calculate their detectability, which takes into account the fundamental initial mass function and formation rates of Pop III stars, from which we find the temporal variability of the afterglows and ultimately the length of time JWST and SPICA can detect them. In the range of plausible Pop III GRB parameters, the afterglows are always detectable by these instruments during the isotropic emission, for a minimum of 55 days and a maximum of 3.7 yr. The average number of detectable afterglows will be 2.96× 10{sup –5} per SPICA field of view (FOV) and 2.78× 10{sup –6} per JWST FOV. These are lower limits, using a pessimistic estimate of Pop III star formation. An optimal observing strategy with SPICA could identify a candidate orphan afterglow in ∼1.3 yr, with a 90% probability of confirmation with further detailed observations. A beamed GRB will align with the FOV of the planned GRB detector Energetic X-ray Imaging Survey Telescope once every 9 yr. Pop III GRBs will be more easily detected by their isotropic emissions (i.e., orphan afterglows) rather than by their prompt emissions.

  14. The Potential for Detecting Gamma-Ray Burst Afterglows from Population III Stars with the Next Generation of Infrared Telescopes

    NASA Astrophysics Data System (ADS)

    Macpherson, D.; Coward, D. M.; Zadnik, M. G.

    2013-12-01

    We investigate the detectability of a proposed population of gamma-ray bursts (GRBs) from the collapse of Population III (Pop III) stars. The James Webb Space Telescope (JWST) and Space Infrared Telescope for Cosmology and Astrophysics (SPICA) will be able to observe the late time infrared afterglows. We have developed a new method to calculate their detectability, which takes into account the fundamental initial mass function and formation rates of Pop III stars, from which we find the temporal variability of the afterglows and ultimately the length of time JWST and SPICA can detect them. In the range of plausible Pop III GRB parameters, the afterglows are always detectable by these instruments during the isotropic emission, for a minimum of 55 days and a maximum of 3.7 yr. The average number of detectable afterglows will be 2.96× 10-5 per SPICA field of view (FOV) and 2.78× 10-6 per JWST FOV. These are lower limits, using a pessimistic estimate of Pop III star formation. An optimal observing strategy with SPICA could identify a candidate orphan afterglow in ~1.3 yr, with a 90% probability of confirmation with further detailed observations. A beamed GRB will align with the FOV of the planned GRB detector Energetic X-ray Imaging Survey Telescope once every 9 yr. Pop III GRBs will be more easily detected by their isotropic emissions (i.e., orphan afterglows) rather than by their prompt emissions.

  15. 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.

  16. Infrared Spectroscopy of Comet 73P/Schwassmann-Wachmann 3 Using the Spitzer Space Telescope

    NASA Astrophysics Data System (ADS)

    Sitko, Michael L.; Lisse, Carey M.; Kelley, Michael S.; Polomski, Elisha F.; Lynch, David K.; Russell, Ray W.; Kimes, Robin L.; Whitney, Barbara A.; Wolff, Michael J.; Harker, David E.

    2011-09-01

    We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 μm thermal emission of comet 73P/Schwassmann-Wachmann 3 (SW3), components B and C. We obtained low spectral resolution (R ~ 100) data over the entire wavelength interval, along with images at 16 and 22 μm. These observations provided an unprecedented opportunity to study nearly pristine material from the surface and what was until recently the interior of an ecliptic comet—the cometary surface having experienced only two prior perihelion passages, and including material that was totally fresh. The spectra were modeled using a variety of mineral types including both amorphous and crystalline components. We find that the degree of silicate crystallinity, ~35%, is somewhat lower than most other comets with strong emission features, while its abundance of amorphous carbon is higher. Both suggest that SW3 is among the most chemically primitive solar system objects yet studied in detail, and that it formed earlier or farther from the Sun than the bulk of the comets studied so far. The similar dust compositions of the two fragments suggest that these are not mineralogically heterogeneous, but rather uniform throughout their volumes. The best-fit particle size distribution for SW3B has a form dn/da ~ a -3.5, close to that expected for dust in collisional equilibrium, while that for SW3C has dn/da ~ a -4.0, as seen mostly in active comets with strong directed jets, such as C/1995 O1 Hale-Bopp. The total mass of dust in the comae plus nearby tail, extrapolated from the field of view of the IRS peak-up image arrays, is (3-5) × 108 kg for B and (7-9) × 108 kg for C. Atomic abundances derived from the spectral models indicate a depletion of O compared to solar photospheric values, despite the inclusion of water ice and gas in the models. Atomic C may be solar or slightly sub-solar, but its abundance is complicated by the potential contribution of spectrally featureless mineral species

  17. Hubble Space Telescope WFC3 Early Release Science: Emission-line Galaxies from Infrared Grism Observations

    NASA Astrophysics Data System (ADS)

    Straughn, Amber N.; Kuntschner, Harald; Kümmel, Martin; Walsh, Jeremy R.; Cohen, Seth H.; Gardner, Jonathan P.; Windhorst, Rogier A.; O'Connell, Robert W.; Pirzkal, Norbert; Meurer, Gerhardt; McCarthy, Patrick J.; Hathi, Nimish P.; Malhotra, Sangeeta; Rhoads, James; Balick, Bruce; Bond, Howard E.; Calzetti, Daniela; Disney, Michael J.; Dopita, Michael A.; Frogel, Jay A.; Hall, Donald N. B.; Holtzman, Jon A.; Kimble, Randy A.; Mutchler, Max; Paresce, Francesco; Saha, Abhijit; Silk, Joseph I.; Trauger, John T.; Walker, Alistair R.; Whitmore, Bradley C.; Young, Erick T.; Xu, Chun

    2011-01-01

    We present grism spectra of emission-line galaxies (ELGs) from 0.6 to 1.6 μm from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95 μm grism data in GOODS-South from the PEARS program, extending the wavelength coverage well past the G800L red cutoff. The Early Release Science (ERS) grism field was observed at a depth of two orbits per grism, yielding spectra of hundreds of faint objects, a subset of which is presented here. ELGs are studied via the Hα, [O III], and [O II] emission lines detected in the redshift ranges 0.2 <~ z <~ 1.4, 1.2 <~ z <~ 2.2, and 2.0 <~ z <~ 3.3, respectively, in the G102 (0.8-1.1 μm R ~= 210) and G141 (1.1-1.6 μm R ~= 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [S II] and [S III] lines). From these relatively shallow observations, line luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 48 ELGs to m AB(F098M) ~= 25 mag. Seventeen GOODS-South galaxies that previously only had photometric redshifts now have new grism-spectroscopic redshifts, in some cases with large corrections to the photometric redshifts (Δz ~= 0.3-0.5). Additionally, one galaxy had no previously measured redshift but now has a secure grism-spectroscopic redshift, for a total of 18 new GOODS-South spectroscopic redshifts. The faintest source in our sample has a magnitude m AB(F098M)= 26.9 mag. The ERS grism data also reflect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample as a function of redshift, consistent with downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes and redshifts to z >~ 2.

  18. HUBBLE SPACE TELESCOPE WFC3 EARLY RELEASE SCIENCE: EMISSION-LINE GALAXIES FROM INFRARED GRISM OBSERVATIONS

    SciTech Connect

    Straughn, Amber N.; Gardner, Jonathan P.; Kuntschner, Harald; Kuemmel, Martin; Walsh, Jeremy R.; Cohen, Seth H.; Windhorst, Rogier A.; Malhotra, Sangeeta; Rhoads, James; O'Connell, Robert W.; Pirzkal, Norbert; Bond, Howard E.; Meurer, Gerhardt; McCarthy, Patrick J.; Hathi, Nimish P.; Balick, Bruce; Calzetti, Daniela; Disney, Michael J.; Dopita, Michael A.; Frogel, Jay A.

    2011-01-15

    We present grism spectra of emission-line galaxies (ELGs) from 0.6 to 1.6 {mu}m from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95 {mu}m grism data in GOODS-South from the PEARS program, extending the wavelength coverage well past the G800L red cutoff. The Early Release Science (ERS) grism field was observed at a depth of two orbits per grism, yielding spectra of hundreds of faint objects, a subset of which is presented here. ELGs are studied via the H{alpha}, [O III], and [O II] emission lines detected in the redshift ranges 0.2 {approx}< z {approx}< 1.4, 1.2 {approx}< z {approx}< 2.2, and 2.0 {approx}< z {approx}< 3.3, respectively, in the G102 (0.8-1.1 {mu}m; R {approx_equal} 210) and G141 (1.1-1.6 {mu}m; R {approx_equal} 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [S II] and [S III] lines). From these relatively shallow observations, line luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 48 ELGs to m A{sub B(F098M)} {approx_equal} 25 mag. Seventeen GOODS-South galaxies that previously only had photometric redshifts now have new grism-spectroscopic redshifts, in some cases with large corrections to the photometric redshifts ({Delta}z {approx_equal} 0.3-0.5). Additionally, one galaxy had no previously measured redshift but now has a secure grism-spectroscopic redshift, for a total of 18 new GOODS-South spectroscopic redshifts. The faintest source in our sample has a magnitude m{sub AB(F098M)}= 26.9 mag. The ERS grism data also reflect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample as a function of redshift, consistent with downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the

  19. 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.

  20. Lunar Interferometric Radio Array: LIRA

    NASA Astrophysics Data System (ADS)

    Abbott, J.; Pixton, S.; Roberts, C.; Reyhanoglu, M.

    2000-01-01

    The Lunar Interferometric Radio Array (LIRA) is a performance driven design, with emphasis on utilizing the unique attributes of the far-side of the moon as a platform for radio astronomy. LIRA consists of three independent Lunar Telescope Units (LTUs), autonomously landed on the moon, and a communications relay satellite orbiting at libration point two (L2). Each LTU deploys a large inflatable spheroid, whose underside has been impregnated with a reflective coating. The spheroid is then gradually hardened into a shell by the suns ultraviolet radiation. LIRA achieves broadband capabilities by operating each LTU independently (tuned to offset frequencies), or provides high resolution observations as a three-element interferometer. The interferometer is functional with as few as two elements, yet will achieve greater resolution with additional elements. Thus, LIRA delivers both redundancy and the possibility for future expansion. Data processing, including interferometric synthesis, occurs at an earth-based ground station, eliminating the need for complex onboard data manipulation.

  1. 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 image performance requirement of 80% encircled energy within a 432 microns diameter circle.

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

    NASA Astrophysics Data System (ADS)

    Hart, M.; Jefferies, S.; Hope, D.; Nagy, J.; Williams, S.

    2014-09-01

    We report daytime sky brightness measurements recorded in the near infrared from the 3.6 m AEOS telescope. Measurements were made at various positions in the sky and separation angles from the sun. The detector was an InGaAs focal plane array in a FLIR SC6000 camera, with images taken through a 50 nm wide filter centered at 1250 nm as well as without any optical filter. The brightness measurements have been calibrated by reference to observations of a photometric standard star in the same bands. We discuss how these new results are motivated by the selection of optimal techniques for high-resolution imaging of satellites from the AEOS telescope.

  3. Physical Conditions of the Earliest Phases of Massive Star Formation: Single-dish and Interferometric Observations of Ammonia and CCS in Infrared Dark Clouds

    NASA Astrophysics Data System (ADS)

    Dirienzo, William J.; Brogan, Crystal; Indebetouw, Rémy; Chandler, Claire J.; Friesen, Rachel K.; Devine, Kathryn E.

    2015-11-01

    Infrared Dark Clouds (IRDCs) harbor the earliest phases of massive star formation, and many of the compact cores in IRDCs, traced by millimeter continuum or by molecular emission in high critical density lines, host massive young stellar objects (YSOs). We used the Robert C. Byrd Green Bank Telescope and the Karl G. Jansky Very Large Array (VLA) to map {NH}{}3 and CCS in nine IRDCs to reveal the temperature, density, and velocity structures and explore chemical evolution in the dense (\\gt {10}22 {cm}{}-2) gas. Ammonia is an excellent molecular tracer for these cold, dense environments. The internal structure and kinematics of the IRDCs include velocity gradients, filaments, and possibly colliding clumps that elucidate the formation process of these structures and their YSOs. We find a wide variety of substructure including filaments and globules at distinct velocities, sometimes overlapping at sites of ongoing star formation. It appears that these IRDCs are still being assembled from molecular gas clumps even as star formation has already begun, and at least three of them appear consistent with the morphology of “hub-filament structures” discussed in the literature. Furthermore, we find that these clumps are typically near equipartition between gravitational and kinetic energies, so these structures may survive for multiple free-fall times.

  4. Hydrous carbonates on Mars?: evidence from Mariner 6/7 infrared spectrometer and ground-based telescopic spectra

    USGS Publications Warehouse

    Calvin, W.M.; King, T.V.V.; Clark, R.N.

    1994-01-01

    Absorption features at 2.28 and 5.4 ??m identified in Mariner 6/7 infrared spectrometer and terrestrial telescopic spectra are consistent with the spectra of hydrous magnesium carbonates such as hydromagnesite and artinite. Spectral characteristics of these hydrous carbonates are different from those of the anhydrous carbonates, as the former do not have the strong spectral features typically associated with anhydrous carbonates such as calcite and siderite. Although the spectroscopic evidence for anhydrous carbonates is scant, the possible presence of hydrous carbonates provides an appealing mechanism for the existence of carbonates on Mars. -from Authors

  5. Optical performance assessment of a fluorescence detector for the telescope array low-energy extension experiment by using the interferometric simulation method

    NASA Astrophysics Data System (ADS)

    Jeong, In Seok; Lee, Jin Ho

    2016-07-01

    The fluorescence detector (FD) of the Telescope Array Low-Energy Extension (TALE) has been designed with different structures comprised of various materials. However, the cycle of expansion and contraction in these materials in response to thermal effects results in structural deformation. Furthermore, because the TALE-FD is exposed to high-temperature environments, significant light dispersion occurs as a result of the substantial deformation of the mirror (due to thermal expansion mismatch); this is considered to be an important issue that must be addressed in order to enhance the array performance and productivity. As the optical surface accuracy may be influenced by the structural deformation, an assessment of any significant structural deformations of the component materials is necessary to increase confidence in the array's operation. The primary purpose of this paper is to identify the relationship between temperature increases and changes in the surface accuracy of the TALE-FD large mirror. For this purpose, Cherenkov light emission and the fluorescence processes of ultra-high-energy cosmic rays (UHECRs) are emulated in order to assess the optical performance of the TALE-FD in practical situations. Additionally, the detection sensitivity of the TALE-FD large mirror is experimentally identified by measuring the distribution of the focused spot produced by incident light over the surface of a photomultiplier tube (PMT) sensor array.

  6. 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.

  7. 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.

  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. A multi-wavelength interferometric study of the massive young stellar object IRAS 13481-6124

    NASA Astrophysics Data System (ADS)

    Boley, Paul A.; Kraus, Stefan; de Wit, Willem-Jan; Linz, Hendrik; van Boekel, Roy; Henning, Thomas; Lacour, Sylvestre; Monnier, John D.; Stecklum, Bringfried; Tuthill, Peter G.

    2016-02-01

    We present new mid-infrared interferometric observations of the massive young stellar object IRAS 13481-6124, using VLTI/MIDI for spectrally-resolved, long-baseline measurements (projected baselines up to ~120 m) and GSO/T-ReCS for aperture-masking interferometry in five narrow-band filters (projected baselines of ~1.8-6.4 m) in the wavelength range of 7.5-13μm. We combine these measurements with previously-published interferometric observations in the K and N bands in order to assemble the largest collection of infrared interferometric observations for a massive YSO to date. Using a combination of geometric and radiative-transfer models, we confirm the detection at mid-infrared wavelengths of the disk previously inferred from near-infrared observations. We show that the outflow cavity is also detected at both near- and mid-infrared wavelengths, and in fact dominates the mid-infrared emission in terms of total flux. For the disk, we derive the inner radius (~1.8 mas or ~6.5 AU at 3.6 kpc), temperature at the inner rim (~1760 K), inclination (~48°) and position angle (~107°). We determine that the mass of the disk cannot be constrained without high-resolution observations in the (sub-)millimeter regime or observations of the disk kinematics, and could be anywhere from ~10-3 to 20M⊙. Finally, we discuss the prospects of interpreting the spectral energy distributions of deeply-embedded massive YSOs, and warn against attempting to infer disk properties from the spectral energy distribution. Based in part on observations with the Very Large Telescope Interferometer of the European Southern Observatory, under program IDs 384.C-0625, 086.C-0543, 091.C-0357.

  11. Optical design for the narrow field infrared adaptive optics system (NFIRAOS) petite on the thirty meter telescope

    NASA Astrophysics Data System (ADS)

    Bauman, Brian J.; Gavel, Donald T.; Dekany, Richard G.; Ellerbroek, Brent L.

    2005-08-01

    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 (WFS) 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.

  12. 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.

  13. Design tradeoffs for a high spectral resolution mid-infrared echelle spectrograph on the Thirty-Meter Telescope

    NASA Astrophysics Data System (ADS)

    Tokunaga, A. T.; Bond, T.; Elias, J.; Chun, M.; Richter, M.; Liang, M.; Lacy, J.; Daggert, L.; Tollestrup, E.; Ressler, M.; Warren, D.; Fisher, S.; Carr, J.

    2006-06-01

    A feasibility design study was undertaken to assess the requirements of a mid-infrared echelle spectrograph (MIRES) with a resolving power of 120,000 and its associated mid-infrared adaptive optics (MIRAO) system on the Thirty-Meter Telescope. Our baseline design incorporates a 2K×2K Si:As array or array mosaic for the spectrograph and a 1K×1K Si:As array for the slit viewer. Various tradeoffs were studied to minimize risk and to optimize the sensitivity of the instrument. Major challenges are to integrate the spectrograph to the MIRAO system and, later, to an adaptive secondary, the procurement of a suitable window and large KRS-5 lenses, and the acquisition of large format mid-IR detector arrays suitable for the range of background conditions. We conclude that the overall risk is relatively low and there is no technical reason that should prevent this instrument from being ready for use at first light on the Thirty- Meter Telescope.

  14. The Search for Optical and Near-Infrared Counterparts of GRBs with the Super-LOTIS Telescope

    NASA Astrophysics Data System (ADS)

    Williams, G. G.; Park, H. S.; Barthelmy, S. D.; Hartmann, D. H.; Hurley, K. C.; Milne, P. A.; Lindsay, K. J.; Bradshaw, M.; Wurtz, R. E.; Wickersham, J.

    2004-09-01

    The 0.6-m Super-LOTIS (Livermore Optical Transient Imaging System) telescope is a fully robotic system dedicated to the search for prompt optical emission from gamma-ray bursts. The telescope began routine operations from its Steward Observatory site atop Kitt Peak in April 2000. We summarize the current capabilities of the system and present some recent scientific results. A progress report is given on the upgrade of the system to allow for simultaneous near-infrared (NIR) and optical imaging. This upgrade will be completed to coincide with the launch of the Swift GRB explorer mission in mid-2004. Swift will have the capability of localizing very high redshift GRBs but absorption by the Ly-α forest prohibits optical detection of z > 5 bursts. NIR observations can detect GRBs out to z ~ 10. Although Swift is a multi-wavelength observatory capable of observing GRBs from the hard x-rays to the optical it has no NIR capability. The upgraded Super-LOTIS telescope will fill this NIR need.

  15. STRAY - An interactive program for the computation of stray radiation in infrared telescopes

    NASA Technical Reports Server (NTRS)

    St. Clair Dinger, Ann

    1987-01-01

    The STRAY program to model the amount of stray radiation reaching the focal plane of a well-baffled telescope is described. The STRAY telescope model is addressed, including the aperture shade, barrel baffle, optics, mirror sectioning and chopping, and off-axis points in focal plane. The possible illumination paths are shown, and calculation options using STRAY are discussed. The stored data and computational aspects of STRAY are addressed. STRAY is compared to the MINI-APART model, and applications of STRAY are described.

  16. 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.

  17. 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.

  18. 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

  19. Effect of the Shuttle contaminant environment on a sensitive infrared telescope

    NASA Technical Reports Server (NTRS)

    Simpson, J. P.; Witteborn, F. C.

    1977-01-01

    A sensitive IR telescope on the Space Shuttle Orbiter will be limited in its performance by fluctuations in the IR radiation from the natural environment and the contaminant atmosphere. Models of the Orbiter's contaminant atmosphere were used to predict its spectral radiance from 3 to 300 microns. At 350 km, statistical fluctuations in the radiation from a water vapor column, and a noise equivalent power were measured. This noise is somewhat smaller than the expected contribution from zodiacal light from 5 to 30 microns. The column density of all IR emitting molecules can be kept low only if restrictions on rocket firings and liquid vents are maintained. The relatively low frequency of particle sightings from Skylab, coupled with improvements in Orbiter venting techniques, indicate that sightings of particles 2 microns and larger in radius will not seriously hamper telescope performance provided that liquid vents and rocket firings are properly restricted.

  20. 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.

  1. Integration and testing of the GRAVITY infrared camera for multiple telescope optical beam analysis

    NASA Astrophysics Data System (ADS)

    Gordo, Paulo; Amorim, Antonio; Abreu, Jorge; Eisenhauer, Frank; Anugu, Narsireddy; Garcia, Paulo; Pfuhl, Oliver; Haug, Marcus; Sturm, Eckhard; Wieprecht, Ekkehard; Perrin, Guy; Brandner, Wolfgang; Straubmeier, Christian; Perraut, Karine; Naia, M. Duarte; Guimarães, M.

    2014-07-01

    The GRAVITY Acquisition Camera was designed to monitor and evaluate the optical beam properties of the four ESO/VLT telescopes simultaneously. The data is used as part of the GRAVITY beam stabilization strategy. Internally the Acquisition Camera has four channels each with: several relay mirrors, imaging lens, H-band filter, a single custom made silica bulk optics (i.e. Beam Analyzer) and an IR detector (HAWAII2-RG). The camera operates in vacuum with operational temperature of: 240k for the folding optics and enclosure, 100K for the Beam Analyzer optics and 80K for the detector. The beam analysis is carried out by the Beam Analyzer, which is a compact assembly of fused silica prisms and lenses that are glued together into a single optical block. The beam analyzer handles the four telescope beams and splits the light from the field mode into the pupil imager, the aberration sensor and the pupil tracker modes. The complex optical alignment and focusing was carried out first at room temperature with visible light, using an optical theodolite/alignment telescope, cross hairs, beam splitter mirrors and optical path compensator. The alignment was validated at cryogenic temperatures. High Strehl ratios were achieved at the first cooldown. In the paper we present the Acquisition Camera as manufactured, focusing key sub-systems and key technical challenges, the room temperature (with visible light) alignment and first IR images acquired in cryogenic operation.

  2. An Interferometric Search for Bright Companions to 51 Pegasi

    NASA Technical Reports Server (NTRS)

    Boden, A. F.; van Belle, G. T.; Colavita, M. M.; Dumont, P. J.; Gubler, J.; Koresko, C. D.; Kulkarni, S. R.; Lane, B. F.; Mobley, D. W.; Shao, M.; Wallace, J. K.

    1998-01-01

    We report on a near-infrared, long-baseline interferometric search for luminous companions to the star 51 Pegasi conducted with the Palomar Testbed Interferometer. Our data is completely consistent with a single-star hypothesis.

  3. 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.

  4. 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.

  5. First Light for Mimir, a Near-Infrared Wide-Field Imager, Spectrometer, and Polarimeter for the Perkins Telescope

    NASA Astrophysics Data System (ADS)

    Clemens, D. P.; Sarcia, D.; Tollestrup, E. V.; Grabau, A.; Bosh, A.; Buie, M.; Taylor, B.; Dunham, E.

    2004-12-01

    The Mimir instrument completed its 5-year development in our Boston University lab and was delivered this past July to Flagstaff, Arizona and the Perkins telescope for commissioning. Mimir is a "facility-class" multi-function near-infrared imager, spectrometer, and polarimeter developed under a joint program by Boston University and Lowell Observatory scientists, staff, and engineers. It fully covers the wavelength range 1-5 microns onto its 1024x1024 Aladdin III InSb array detector. In its wide-field imaging mode, a 10x10 arcmin field is sampled at 0.6 arcsec per pixel. In its narrow-field mode, the field is 3x3 arcmin, sampled at 0.2 arcsec per pixel. A full complement of JHKsL'M' broad-band filters are present in its four filter wheels. Spectroscopy is accomplished using a matched slit-plate and selector system, three grisms, and special spectroscopy filters (for order suppression). Polarimetry is accomplished using rotating half-wave plates and a fixed wire grid. All of these modes were certified in the lab; all have been certified at the Perkins telescope during the August/September commissioning run. Mode switches are accomplished in a matter of only seconds, making Mimir exceedingly versatile. The poster highlights the designs and components of Mimir as well as examples of images, spectra, and polarimetry from the commissioning telescope runs this past fall. Internal, shared-risk observations with Mimir begin this quarter. Mimir design and development has been funded by NASA, NSF, and the W.M. Keck Foundation.

  6. 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.

  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. Stray light analysis of CRISTA - The Cryogenic Infrared Spectrometer and Telescope of the Atmosphere

    NASA Astrophysics Data System (ADS)

    Breault, Robert P.; Barthol, Peter

    1990-12-01

    The CRISTA experiment is designed to detect and analyze short term upper atmospheric waves and turbulence of the middle atmosphere. This paper presents two of the more intriguing stray light characteristics of the CRISTA instrument as revealed through a much more extensive stray light analysis. The two topics are the diffraction propagation from a series of edges, and the thermal loading characteristics of the outer baffles by the earth's radiation. The interesting parameters that play very complex roles relative to each other are: CRISTA's three different telescopes peer through a common aperture; the Center Telescope has an image plane shared by two spectrometers offset above or below the axis by 0.358 deg; the point source angles walk away from one slit but across the other; the wavelength bands vary from 4 microns to 70 microns; all of the imaging mirrors are simple spherical surfaces; the major source of stray light is the earth, which is only .5 deg from the optical axis; and the intermediate field stop is oversized.

  9. 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.

  10. 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.

  11. A TYPE Ia SUPERNOVA AT REDSHIFT 1.55 IN HUBBLE SPACE TELESCOPE INFRARED OBSERVATIONS FROM CANDELS

    SciTech Connect

    Rodney, Steven A.; Riess, Adam G.; Jones, David O.; Dahlen, Tomas; Ferguson, Henry C.; Casertano, Stefano; Grogin, Norman A.; Strolger, Louis-Gregory; Hjorth, Jens; Frederiksen, Teddy F.; Weiner, Benjamin J.; Mobasher, Bahram; Challis, Peter; Kirshner, Robert P.; Filippenko, Alexei V.; Garnavich, Peter; Hayden, Brian; Graur, Or; Jha, Saurabh W.; and others

    2012-02-10

    We report the discovery of a Type Ia supernova (SN Ia) at redshift z = 1.55 with the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data of the Hubble Ultra Deep Field and followed as part of the CANDELS+CLASH Supernova project, comprising the SN search components from those two HST multi-cycle treasury programs. This is the highest redshift SN Ia with direct spectroscopic evidence for classification. It is also the first SN Ia at z > 1 found and followed in the infrared, providing a full light curve in rest-frame optical bands. The classification and redshift are securely defined from a combination of multi-band and multi-epoch photometry of the SN, ground-based spectroscopy of the host galaxy, and WFC3-IR grism spectroscopy of both the SN and host. This object is the first of a projected sample at z > 1.5 that will be discovered by the CANDELS and CLASH programs. The full CANDELS+CLASH SN Ia sample will enable unique tests for evolutionary effects that could arise due to differences in SN Ia progenitor systems as a function of redshift. This high-z sample will also allow measurement of the SN Ia rate out to z Almost-Equal-To 2, providing a complementary constraint on SN Ia progenitor models.

  12. Long-wavelength infrared camera (LWIRC): a 10 micron camera for the Keck telescope

    NASA Astrophysics Data System (ADS)

    Wishnow, Edward H.; Danchi, William C.; Tuthill, Peter G.; Wurtz, Ronald E.; Jernigan, J. G.; Arens, John F.

    1998-08-01

    The long wavelength IR camera 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 micrometers using ZnSe transmissive optics. A set of filters, a circular variable filter, and a mid-IR polarizer are available, as are three plate scales: 0.05 inch, 0.10 inch, 0.12 inch 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 wit both the hardware and software of the other Keck IR instruments NIRC and LWS. A new pre-amplifier/A-D converter has been designed and constructed which decreases greatly the system susceptibility to noise.

  13. 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.

  14. 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.

  15. Infrared Narrowband Tomography of the Local Starburst NGC 1569 with the Large Binocular Telescope/LUCIFER

    NASA Astrophysics Data System (ADS)

    Pasquali, A.; Bik, A.; Zibetti, S.; Ageorges, N.; Seifert, W.; Brandner, W.; Rix, H.-W.; Jütte, M.; Knierim, V.; Buschkamp, P.; Feiz, C.; Gemperlein, H.; Germeroth, A.; Hofmann, R.; Laun, W.; Lederer, R.; Lehmitz, M.; Lenzen, R.; Mall, U.; Mandel, H.; Müller, P.; Naranjo, V.; Polsterer, K.; Quirrenbach, A.; Schäffner, L.; Storz, C.; Weiser, P.

    2011-04-01

    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 μm, [Fe II] 1.64 μm, and Brγ narrowband filters. We obtained high-quality spatial maps of He I 1.08 μm, [Fe II] 1.64 μm, and Brγ emission across the galaxy, and used them together with Hubble Space Telescope/Advanced Camera for Surveys images of NGC 1569 in the Hα 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 Hα/Brγ flux ratio) is rather patchy and, on average, higher in the northwest (NW) portion of the galaxy (E g(B - V) ~= 0.71 mag) than in the southeast (E g(B - V) ~= 0.57 mag). Similarly, the surface density of SFR (computed from either the dereddened Hα or dereddened Brγ image) peaks in the NW region of NGC 1569, reaching a value of about 4 × 10-6 M sun yr-1 pc-2. The total SFR as estimated from the integrated, dereddened Hα (or, alternatively, Brγ) luminosity is about 0.4 M sun yr-1, and the total supernova rate from the integrated, dereddened [Fe II] 1.64 μm luminosity is about 0.005 yr-1 (assuming a distance of 3.36 Mpc). The azimuthally averaged [Fe II] 1.64 μm/Brγ 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 from the integrated, dereddened Hα and He I 1.08 μm luminosities suggests that the latest burst of star formation occurred about 4 Myr

  16. Fabrication of Metallic Freefrom Mirrors for Wide-Field Space Infrared Telescope

    NASA Astrophysics Data System (ADS)

    Jeong, Byeongjoon; Pak, Soojong; kim, Sanghyuk; Lee, Kwangjo; Chang, Seunghyuk; KIM, GUN HEE; Hyun, Sangwon; Jeon, Min Woo

    2016-01-01

    We experimentally demonstrate an error compensation method for high form accuracy of metallic freeform mirrors. The technique is based on single point diamond turning on the rotational asymmetric surfaces. We compensate tool path by subtracting form error patterns which are converted into the polynomial expression. The experimental results illustrate that RMS form error value is reduced from 1.168um to 0.211um which is applicable in Near Infrared regions. We analyze that error compensation is also applicable to the rotational asymmetric tool path. We highlight that our approach is applied only diamond turning technique without additional manufacturing process like polishing and figuring. The proposed scheme is useful to enhance productivity of freeform mirrors.

  17. 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.

  18. NIRIS: The Second Generation Near-Infrared Imaging Spectro-polarimeter for the 1.6 Meter New Solar Telescope

    NASA Astrophysics Data System (ADS)

    Cao, W.; Goode, P. R.; Ahn, K.; Gorceix, N.; Schmidt, W.; Lin, H.

    2012-12-01

    The largest aperture solar telescope, the 1.6 m New Solar Telescope (NST) has been installed at the Big Bear Solar Observatory (BBSO). To take full advantage of the NST's greatest potential, we are upgrading the routinely operational InfraRed Imaging Magnetograph (IRIM) to its second generation, the NIRIS (Near-InfraRed Imaging Spectropolarimeter). NIRIS will offer unprecedented high resolution spectroscopic and polarimetric imaging data of the solar atmosphere from the deepest photosphere through the base of the corona. With the aid of the BBSO adaptive optics (AO) system, the spatial resolution will be close to the diffraction limit of the NST. The spectroscopic cadence will reach one second, while polarimetric measurements, including Stokes I, Q, U, V profiles, remain at a better than 10 s cadence. Polarization sensitivity is expected to be reach ˜ 10-4Ic. NIRIS will cover a broad spectral range from 1.0 to 1.7μm, with particular attention to two unique spectral lines: the Fe I 1565 nm doublet has already proven to be the most sensitive to Zeeman effect for probing the magnetic field in the deepest photosphere; the He I 1083 nm multiplet is one of the best currently available diagnostic of upper chromospheric magnetic fields that allows one to map the vector field at the base of the corona. NIRIS will be built on dual Fabry-Pérot Interferometers (FPIs), each of which has an aperture of 100 mm. The larger aperture of FPIs allows the available field-of-view up to one and half minutes with a spectral power of ˜ 105.

  19. Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) data processing and atmospheric temperature and trace gas retrieval

    NASA Astrophysics Data System (ADS)

    Riese, M.; Spang, R.; Preusse, P.; Ern, M.; Jarisch, M.; Offermann, D.; Grossmann, K. U.

    1999-07-01

    The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment aboard the Shuttle Pallet Satellite (SPAS) was successfully flown in early November 1994 (STS 66) and in August 1997 (STS 85). This paper focuses on the first flight of the instrument, which was part of the Atmospheric Laboratory for Application and Science 3 (ATLAS 3) mission of NASA. During a free flying period of 7 days, limb scan measurements of atmospheric infrared emissions were performed in the 4 to 71 μm wavelength region. For improved horizontal resolution, three telescopes (viewing directions) were used that sensed the atmosphere simultaneously. Atmospheric pressures, temperatures, and volume mixing ratios of various trace gases were retrieved from the radiance data by using a fast onion-peeling retrieval technique. This paper gives an overview of the data system including the raw data processing and the temperature and trace gas profile retrieval. Examples of version 1 limb radiance data (level 1 product) and version 1 mixing ratios (level 2 product) of ozone, ClONO2, and CFC-11 are given. A number of important atmospheric transport processes can already be identified in the level 1 limb radiance data. Radiance data of the lower stratosphere (18 km) indicate strong upwelling in some equatorial regions, centered around the Amazon, Congo, and Indonesia. Respective data at the date line are consistent with convection patterns associated with El Niño. Very low CFC-11 mixing ratios occur inside the South Polar vortex and cause low radiance values in a spectral region sensitive to CFC-11 emissions. These low values are a result of considerable downward transport of CFC-11 poor air that occurred during the winter months. Limb radiance profiles and retrieved mixing ratio profiles of CFC-11 indicate downward transport over ˜5 km. The accuracy of the retrieved version 1 mixing ratios is rather different for the various trace gases. In the middle atmosphere the estimated

  20. 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.

  1. Development of MIMIZUKU: a mid-infrared multi-field imager for 6.5-m TAO telescope

    NASA Astrophysics Data System (ADS)

    Kamizuka, Takafumi; Miyata, Takashi; Sako, Shigeyuki; Nakamura, Tomohiko; Asano, Kentaro; Uchiyama, Mizuho; Okada, Kazushi; Onaka, Takashi; Sakon, Itsuki; Kataza, Hirokazu; Sarugaku, Yuki; Yoshii, Yuzuru; Doi, Mamoru; Kohno, Kotaro; Kawara, Kimiaki; Tanaka, Masuo; Motohara, Kentaro; Tanabe, Toshihiko; Minezaki, Takeo; Morokuma, Tomoki; Tamura, Yoichi; Aoki, Tsutomu; Soyano, Takao; Tarusawa, Ken'ichi; Kato, Natsuko; Konishi, Masahiro; Takahashi, Hidenori; Koshida, Shintaro; Tateuchi, Ken; Handa, Toshihiro

    2012-09-01

    TAO (The University of Tokyo Atacama Observatory) is planned to be constructed at the summit of Co. Chajnantor (5640 m altitude) in Chile. MIMIZUKU (Mid-Infrared Multi-field Imager for gaZing at the UnKnown Universe) is a mid-infrared imager (Field of View: 1' x 1'- 2' x 2') and spectrometer (Δλ/λ: 60-230) for the 6.5-m TAO telescope, covering the wavelength range of 2-38 μm. The MIMIZUKU has a unique equipment called Field Stacker (FS) which enables the simultaneous observation of target and reference object. The simultaneity is expected to improve photometric accuracy and to realize long-term monitoring observations. The development status of the MIMIZUKU is reported in this paper. The FS and the cryostat of the MIMIZUKU have been fabricated and under testing. The cold optics (550 mm x 750 mm x 2 floors) with 28 mirrors has been constructed. The mirrors were aligned with the positional precision of 0.1 mm and the angular precision of 0.1 deg. The evaluated optical performance is that the diffraction-limited image at λ <8 μm and the enough compact image (r <2 pix=0.22") at 2 λ ~2μm can be obtained. In the cold optics, the drive systems with backlash-less gears are employed and work well even in cryogenic environment. The grisms made with silicon and germanium have been fabricated by ultraprecision cutting. It was found that their surface roughness, grating constant, and blaze angle almost measure up to the designed values.

  2. 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.

  3. Micro-Spec: an integrated direct-detection spectrometer for far-infrared space telescopes

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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 μm wavelength range which will enable a wide range of flight missions that would otherwise be challenging due to the 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 ~10 cm2 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 μ-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 ~0:004 radians were developed for initial demonstration and will be the basis of future instruments with resolving power up to about 1200.

  4. 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.

  5. Interferometric synthetic aperture microscopy

    NASA Astrophysics Data System (ADS)

    Ralston, Tyler S.

    State-of-the-art interferometric microscopies have problems representing objects that lie outside of the focus because the defocus and diffraction effects are not accounted for in the processing. These problems occur because of the lack of comprehensive models to include the scattering effects in the processing. In this dissertation, a new modality in three-dimensional (3D) optical microscopy, Interferometric Synthetic Aperture Microscopy (ISAM), is introduced to account for the scattering effects. Comprehensive models for interferometric microscopy, such as optical coherence tomography (OCT) are developed, for which forward, adjoint, normal, and inverse operators are formulated. Using an accurate model for the probe beam, the resulting algorithms demonstrate accurate linear estimation of the susceptibility of an object from the interferometric data. Using the regularized least squares solution, an ISAM reconstruction of underlying object structure having spatially invariant resolution is obtained from simulated and experimental interferometric data, even in regions outside of the focal plane of the lens. Two-dimensional (2D) and 3D interferometric data is used to resolve objects outside of the confocal region with minimal loss of resolution, unlike in OCT. Therefore, high-resolution details are recovered from outside of the confocal region. Models and solutions are presented for the planar-scanned, the rotationally scanned, and the full-field illuminated geometry. The models and algorithms presented account for the effects of a finite beam width, the source spectrum, the illumination and collection fields, as well as defocus, diffraction and dispersion effects.

  6. Flight model performance of the integral field unit for the James Webb Space Telescope's near-infrared spectrograph

    NASA Astrophysics Data System (ADS)

    Purll, David J.; Lobb, Daniel R.; Barnes, Andrew R.; Talbot, R. Gordon; Rolt, Stephen; Robertson, David J.; Closs, Martin F.; te Plate, Maurice

    2010-07-01

    The Near Infrared Spectrograph (NIRSpec) developed by EADS Astrium GmbH for the European Space Agency (ESA) is a spectrograph covering the 0.6-5.0 μm waveband to fly on the James Webb Space Telescope (JWST). NIRSpec will be primarily operated as a multi-object spectrograph but also includes an integral field unit (IFU) allowing a 3×3 arcsec field of view to be sampled continuously with 0.1 arcsec spatial resolution. The IFU, based on an advanced image slicer concept, is a very compact athermal unit made of aluminium. It contains three 30-element monolithic mirror arrays forming slicer, pupil and slit mirrors, and single-surface image relay and plane fold mirrors, produced using 5-axis diamond-machining techniques. Many of the mirrors have complex surfaces like toric sections with 3rd-order corrections in order to achieve the required performance within a small allowed volume, and could only have been fabricated with the most advanced free-form machining. The mechanical design accommodates the differential expansion between the aluminium IFU and its titanium parent assembly across a 250K drop to operating temperature using an isostatic mounting system. This paper presents the development of the IFU from the design and diamond-machining techniques to the optical and cryogenic testing of the assembled flight model unit.

  7. Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer Observations of the GLIMPSE9 Stellar Cluster

    NASA Astrophysics Data System (ADS)

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

    2010-01-01

    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 - KS = ~1 mag, indicating an interstellar extinction A _K_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 sun, integrated down to 1 M 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. W.M. Keck Telescope High Resolution Near-Infrared Imaging of FSC 10214+4724: Evidence for Gravitational Lensing

    NASA Astrophysics Data System (ADS)

    Liu, Michael C.; Graham, James R.

    1995-05-01

    We present near--infrared observations of the ultraluminous high--redshift (z=2.286) IRAS source FSC 10214+4724 obtained in 0.''4 seeing at the W. M. Keck Telescope. These new observations show that FSC 10214+4724 consists of a highly symmetric circular arc centered on a second weaker source. The arc has an angular extent of about 140(deg) and is probably unresolved in the transverse direction. This morphology constitutes compelling prima facie evidence for a gravitationally lensed system. Our images also contain evidence for the faint counter image predicted by the lens hypothesis. The morphology of FSC 10214+4724 can be explained in terms of a gravitationally lensed background source if the object located close to the center of the arc is an L(*) galaxy located at z~ 0.4 . The origin of the luminosity of FSC 10214+4724 is unclear -- it may be a protogalaxy undergoing its initial burst of star formation or a highly obscured quasar. If FSC 10214+4724 is lensed then there is significant magnification and its luminosity has been overestimated by a large factor. Our results suggest FSC 10214+4724 is not a uniquely luminous object but ranks among the most powerful quasars and ultraluminous IRAS galaxies.

  9. 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.

  10. 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.

  11. Development of a simultaneous two-color near-infrared multi-object spectrograph SWIMS for the TAO 6.5-m telescope

    NASA Astrophysics Data System (ADS)

    Motohara, Kentaro; Konishi, Masahiro; Takahashi, Hidenori; Tateuchi, Ken; Kitagawa, Yutaro; Todo, Soya; Kato, Natsuko M.; Ohsawa, Ryou; Aoki, Tsutomu; Asano, Kentaro; Doi, Mamoru; Kamizuka, Takafumi; Kawara, Kimiaki; Kohno, Kotaro; Koshida, Shintaro; Minezaki, Takeo; Miyata, Takashi; Morokuma, Tomoki; Okada, Kazushi; Sako, Shigeyuki; Soyano, Takao; Tamura, Yoichi; Tanabe, Toshihiko; Tanaka, Masuo; Tarusawa, Ken'ichi; Uchiyama, Mizuho; Yoshii, Yuzuru

    2014-07-01

    Simultaneous Color Wide-field Infrared Multi-object Spectrograph, SWIMS, is one of the first generation in- struments for the University of Tokyo Atacama Observatory (TAO) 6.5m Telescope now under construction. A dichroic mirror being inserted in the collimated beam, it is capable of two-color simultaneous imaging with FoV of 9:16φ or R ˜ 1000 multi-object spectroscopy at 0.9-2.5μm wavelength range in one shot, and enables us to carry out efficient NIR imaging/spectroscopic survey of objects such as distant galaxies and young stellar objects. All the major components have been fabricated and we will start integration and laboratory cool-down test in the summer of 2014. After the engineering and initial science observations at the Subaru telescope, SWIMS will be transported to TAO telescope and see the first light in 2018.

  12. Adaptive optics for array telescopes using piston-and-tilt wave-front sensing

    NASA Technical Reports Server (NTRS)

    Wizinowich, P.; Mcleod, B.; Lloyd-Yhart, M.; Angel, J. R. P.; Colucci, D.; Dekany, R.; Mccarthy, D.; Wittman, D.; Scott-Fleming, I.

    1992-01-01

    A near-infrared adaptive optics system operating at about 50 Hz has been used to control phase errors adaptively between two mirrors of the Multiple Mirror Telescope by stabilizing the position of the interference fringe in the combined unresolved far-field image. The resultant integrated images have angular resolutions of better than 0.1 arcsec and fringe contrasts of more than 0.6. Measurements of wave-front tilt have confirmed the wavelength independence of image motion. These results show that interferometric sensing of phase errors, when combined with a system for sensing the wave-front tilt of the individual telescopes, will provide a means of achieving a stable diffraction-limited focus with segmented telescopes or arrays of telescopes.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. The science case and data processing strategy for the Thinned Aperture Light Collector (TALC): a project for a 20m far-infrared space telescope

    NASA Astrophysics Data System (ADS)

    Sauvage, Marc; Chanial, Pierre; Durand, Gilles A.; Rodriguez, Louis R.; Starck, Jean-Luc; Ronayette, Samuel; Aussel, Hervé; Minier, Vincent; Motte, Frédérique; Pantin, Eric J.; Sureau, Florent; Terrisse, Robin

    2014-08-01

    The future of far-infrared observations rests on our capacity to reach sub-arcsecond angular resolution around 100 μm, in order to achieve a significant advance with respect to our current capabilities. Furthermore, by reaching this angular resolution we can bridge the gap between capacities offered by the JWST in the near infrared and those allowed by ALMA in the submillimeter, and thus benefit from similar resolving capacities over the whole wavelength range where interstellar dust radiates and where key atomic and molecular transitions are found. In an accompanying paper,1 we present a concept of a deployable annular telescope, named TALC for Thinned Aperture Light Collector, reaching 20m in diameter. Being annular, this telescope features a main beam width equivalent to that of a 27m telescope, i.e. an angular resolution of 0.92" at 100 μm. In this paper we focus on the science case of such a telescope as well on the aspects of unconventional data processing that come with this unconventional optical configuration. The principal science cases of TALC revolve around its imaging capacities, that allow resolving the Kuiper belt in extra-solar planetary systems, or the filamentary scale in star forming clouds all the way to the Galactic Center, or the Narrow Line Region in Active Galactic Nuclei of the Local Group, or breaking the confusion limit to resolve the Cosmic Infrared Background. Equipping this telescope with detectors capable of imaging polarimetry offers as well the extremely interesting perspective to study the influence of the magnetic field in structuring the interstellar medium. We will then present simulations of the optical performance of such a telescope. The main feature of an annular telescope is the small amount of energy contained in the main beam, around 30% for the studied configuration, and the presence of bright diffraction rings. Using simulated point spread functions for realistic broad-band filters, we study the observing performance

  18. Robust snapshot interferometric spectropolarimetry.

    PubMed

    Kim, Daesuk; Seo, Yoonho; Yoon, Yonghee; Dembele, Vamara; Yoon, Jae Woong; Lee, Kyu Jin; Magnusson, Robert

    2016-05-15

    This Letter describes a Stokes vector measurement method based on a snapshot interferometric common-path spectropolarimeter. The proposed scheme, which employs an interferometric polarization-modulation module, can extract the spectral polarimetric parameters Ψ(k) and Δ(k) of a transmissive anisotropic object by which an accurate Stokes vector can be calculated in the spectral domain. It is inherently strongly robust to the object 3D pose variation, since it is designed distinctly so that the measured object can be placed outside of the interferometric module. Experiments are conducted to verify the feasibility of the proposed system. The proposed snapshot scheme enables us to extract the spectral Stokes vector of a transmissive anisotropic object within tens of msec with high accuracy. PMID:27176992

  19. 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

  20. 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.

  1. Telescope With Reflecting Baffle

    NASA Technical Reports Server (NTRS)

    Linlor, W. I.

    1985-01-01

    Telescope baffle made from combination of reflecting surfaces. In contrast with previous ellipsoidal reflecting baffles, new baffle reflects skew rays more effectively and easier to construct. For infrared telescopes, reflecting baffles better than absorbing baffles because heat load reduced, and not necessary to contend with insufficiency of infrared absorption exhibited by black coatings.

  2. Coma-compensation telescope

    NASA Technical Reports Server (NTRS)

    MacFarlane, Malcolm J. (Inventor)

    1986-01-01

    A telescope for eliminating on axis coma due to tilt of the secondary mirror in infrared astronomy. The secondary mirror of a reflecting telescope is formed to cause field coma to always be equal and opposite at the optical axis of the telescope to tilt coma regardless of the angle through the secondary mirror is tilted with respect to the optical axis.

  3. 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

  4. 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

  5. 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.

  6. Modeling the diurnal tide for the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) 1 time period

    NASA Astrophysics Data System (ADS)

    Oberheide, Jens; Hagan, Maura E.; Ward, William E.; Riese, Martin; Offermann, Dirk

    2000-11-01

    High-resolution stratospheric and mesospheric temperature measurements from the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment taken during the space shuttle mission STS 66 in November 1994 show large tidal signatures in the day/night temperature differences. Previous comparisons with the predictions of the global-scale wave model (GSWM-95) for equinox conditions have shown these differences to be in very good qualitative agreement with GSWM results for the diurnal component of the migrating solar tide, although quantitative differences in the tidal amplitudes and phases did exist. In this paper the source of these differences is examined. Background fields corresponding to the flight conditions are derived from the CRISTA data and used as input to an updated version of the GSWM. The updated GSWM includes revised tidal heating and dissipation schemes. The background fields from CRISTA include temperature, ozone, pressure, mass density, and derived geostrophic wind (in geostrophic balance with the CRISTA temperatures). These model updates significantly improve the agreement with the CRISTA observations at all latitudes and altitudes. Modeled and observed phases match to within 1 hour at the equator. The amplitudes agree within 1 K for most altitudes. Above 75 km, however, the CRISTA measurements show a decrease in the tidal amplitude which is not present in the GSWM results, suggesting that the model underestimates the equatorial gravity wave dissipation in the form of eddy diffusivity and wave stress in the upper mesosphere. The mesospheric wind field update accounts for the most profound improvement in the phase distributions of the diurnal tide. The results show the strengths of the GSWM but also indicate the need for some model improvements. Our determination of the GSWM capability for reliable predictions of phases and amplitudes of the migrating diurnal tide when realistic atmospheric background conditions are used

  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. Error-Compensated Telescope

    NASA Technical Reports Server (NTRS)

    Meinel, Aden B.; Meinel, Marjorie P.; Stacy, John E.

    1989-01-01

    Proposed reflecting telescope includes large, low-precision primary mirror stage and small, precise correcting mirror. Correcting mirror machined under computer control to compensate for error in primary mirror. Correcting mirror machined by diamond cutting tool. Computer analyzes interferometric measurements of primary mirror to determine shape of surface of correcting mirror needed to compensate for errors in wave front reflected from primary mirror and commands position and movement of cutting tool accordingly.

  10. 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.

  11. 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.

  12. 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)

  13. 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...

  14. 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.

  15. 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).

  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. High resolution telescope

    SciTech Connect

    Massie, N.A.; Oster, Y.

    1990-01-01

    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 2.1m in a circle-of-nine configuration. The telescope array has an effective aperture of 12m 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 activities. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes. 9 figs., 1 tab.

  18. High resolution telescope

    SciTech Connect

    Massie, N.A.; Oster, Y.

    1990-12-31

    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 2.1m in a circle-of-nine configuration. The telescope array has an effective aperture of 12m 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 activities. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes. 9 figs., 1 tab.

  19. Sculpting the disk around T Chamaeleontis: an interferometric view

    NASA Astrophysics Data System (ADS)

    Olofsson, J.; Benisty, M.; Le Bouquin, J.-B.; Berger, J.-P.; Lacour, S.; Ménard, F.; Henning, Th.; Crida, A.; Burtscher, L.; Meeus, G.; Ratzka, T.; Pinte, C.; Augereau, J.-C.; Malbet, F.; Lazareff, B.; Traub, W.

    2013-04-01

    Context. Circumstellar disks are believed to be the birthplace of planets and are expected to dissipate on a timescale of a few Myr. The processes responsible for the removal of the dust and gas will strongly modify the radial distribution of the circumstellar matter and consequently the spectral energy distribution. In particular, a young planet will open a gap, resulting in an inner disk dominating the near-IR emission and an outer disk emitting mostly in the far-infrared. Aims: We analyze a full set of data involving new near-infrared data obtained with the 4-telescope combiner (VLTI/PIONIER), new mid-infrared interferometric VLTI/MIDI data, literature photometric and archival data from VLT/NaCo/SAM to constrain the structure of the transition disk around T Cha. Methods: After a preliminary analysis with a simple geometric model, we used the MCFOST radiative transfer code to simultaneously model the SED and the interferometric observables from raytraced images in the H-, L'-, and N-bands. Results: We find that the dust responsible for the strong emission in excess in the near-IR must have a narrow temperature distribution with a maximum close to the silicate sublimation temperature. This translates into a narrow inner dusty disk (0.07-0.11 AU), with a significant height (H/r ~ 0.2) to increase the geometric surface illuminated by the central star. We find that the outer disk starts at about 12 AU and is partially resolved by the PIONIER, SAM, and MIDI instruments. We discuss the possibility of a self-shadowed inner disk, which can extend to distances of several AU. Finally, we show that the SAM closure phases, interpreted as the signature of a candidate companion, may actually trace the asymmetry generated by forward scattering by dust grains in the upper layers of the outer disk. These observations help constrain the inclination and position angle of the disk to about + 58° and - 70°, respectively. Conclusions: The circumstellar environment of T Cha appears

  20. 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.

  1. 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.

  2. Interferometric rotation sensor

    NASA Technical Reports Server (NTRS)

    Walsh, T. M. (Inventor)

    1973-01-01

    An interferometric rotation sensor and control system is provided which includes a compound prism interferometer and an associated direction control system. Light entering the interferometer is split into two paths with the light in the respective paths being reflected an unequal number of times, and then being recombined at an exit aperture in phase differing relationships. Incoming light is deviated from the optical axis of the device by an angle, alpha. The angle causes a similar displacement of the two component images at the exit aperture which results in a fringe pattern. Fringe numbers are directly related to angle alpha. Various control systems of the interferometer are given.

  3. MID-INFRARED PROPERTIES OF THE SWIFT BURST ALERT TELESCOPE ACTIVE GALACTIC NUCLEI SAMPLE OF THE LOCAL UNIVERSE. I. EMISSION-LINE DIAGNOSTICS

    SciTech Connect

    Weaver, K. A.; Melendez, M.; Mushotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth, E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; Winter, L. M.; Armus, L.

    2010-06-20

    We compare mid-infrared emission-line properties from high-resolution Spitzer spectra of a hard X-ray (14-195 keV) selected sample of nearby (z < 0.05) active galactic nuclei (AGNs) detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared emission lines, [O IV] 25.89 {mu}m, [Ne II] 12.81 {mu}m, [Ne III] 15.56 {mu}m, and [Ne V] 14.32/24.32 {mu}m, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations; however, six newly discovered BAT AGNs are under-luminous in [O IV], most likely the result of dust extinction in the host galaxy. The overall tightness of the mid-infrared correlations and BAT fluxes and luminosities suggests that the emission lines primarily arise in gas ionized by the AGNs. We also compare the mid-infrared emission lines in the BAT AGNs with those from published studies of ULIRGs, Palomar-Green quasars, star-forming galaxies, and LINERs. We find that the BAT AGN sample falls into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] ratios. These line ratios are lower in sources that have been previously classified in the mid-infrared/optical as AGNs than those found for the BAT AGNs, suggesting that, in our X-ray selected sample, the AGNs represent the main contribution to the observed line emission. These ratios represent a new emission line diagnostic for distinguishing between AGNs and star-forming galaxies.

  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. Design and control of one precise tracking simulation bed for Chinese 20/30 meter optic/infrared telescope

    NASA Astrophysics Data System (ADS)

    Ren, Changzhi; Li, Xiaoyan; Song, Xiaoli; Niu, Yong; Li, Aihua; Zhang, Zhenchao

    2012-09-01

    Direct drive technology is the key to solute future 30-m and larger telescope motion system to guarantee a very high tracking accuracy, in spite of unbalanced and sudden loads such as wind gusts and in spite of a structure that, because of its size, can not be infinitely stiff. However, this requires the design and realization of unusually large torque motor that the torque slew rate must be extremely steep too. A conventional torque motor design appears inadequate. This paper explores one redundant unit permanent magnet synchronous motor and its simulation bed for 30-m class telescope. Because its drive system is one high integrated electromechanical system, one complexly electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. This paper discusses the design and control of the precise tracking simulation bed in detail.

  6. 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. PMID:21668135

  7. 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.

  8. Noise properties and signal-dependent interpixel crosstalk of the detectors of the Near-Infrared Spectrograph of the James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Giardino, Giovanna; Sirianni, Marco; Birkmann, Stephan M.; Rauscher, Bernard J.; Lindler, Don; Böker, Torsten; Ferruit, Pierre; De Marchi, Guido; Stuhlinger, Martin; Jensen, Peter; Strada, Paolo

    2013-03-01

    The Near-Infrared Spectrograph (NIRSpec) is one of the four science instruments of the James Webb Space Telescope. Its focal plane consists of two HAWAII-2RG sensors operating in the wavelength range of 0.6 to 5.0 μm and, as part of characterizing NIRSpec, the noise properties of these detectors under dark and illuminated conditions were studied. Under dark conditions, and as already known, 1/f noise in the detector system causes somewhat higher noise levels than can be accounted for by a simple model that includes white read noise and shot noise on integrated charge. More surprisingly, for high levels of accumulated charge, significantly lower total noise than expected was observed. This effect is shown to be due to pixel-to-pixel correlations introduced by signal-dependent interpixel crosstalk, with an interpixel coupling factor, α, that ranges from ˜0.01 for zero signal to ˜0.03 close to saturation.

  9. ASTROCAM: offner re-imaging 1024 X 1024 InSb camera for near-infrared astrometry on the USNO 1.55-m telescope

    NASA Astrophysics Data System (ADS)

    Fischer, Jacqueline; Vrba, Frederick J.; Toomey, Douglas W.; Lucke, Bob L.; Wang, Shu-i.; Henden, Arne A.; Robichaud, Joseph L.; Onaka, Peter M.; Hicks, Brian; Harris, Frederick H.; Stahlberger, Werner E.; Kosakowski, Kris E.; Dudley, Charles C.; Johnston, Kenneth J.

    2003-03-01

    In order to extend the US Naval Observatory (USNO) small-angle astrometric capabilities to near infrared wavelengths we have designed and manufactured a 1024 x 1024 InSb re-imaging infrared camera equipped with an array selected from the InSb ALADDIN (Advanced Large Area Detector Development in InSb) development program and broadband and narrowband 0.8 - 3.8 μm filters. Since the USNO 1.55-m telescope is optimized for observations at visible wavelengths with an oversized secondary mirror and sky baffles, the straylight rejection capabilities of the ASTROCAM Lyot stop and baffles are of critical importance for its sensitivity and flat- fielding capabilities. An Offner relay was chosen for the heart of the system and was manufactured from the same melt of aluminum alloy to ensure homologous contraction from room temperature to 77 K. A blackened cone was installed behind the undersized hole (the Lyot stop) in the Offner secondary. With low distortion, a well-sampled point spread function, and a large field of view, the system is well suited for astrometry. It is telecentric, so any defocus will not result in a change of image scale. The DSP-based electronics allow readout of the entire array with double-correlated sampling in 0.19 seconds, but shorter readout is possible with single sampling or by reading out only small numbers of subarrays. In this paper we report on the optical, mechanical, and electronic design of the system and present images and results on the sensitivity and astrometric stability obtained with the system, now operating routinely at the 1.55-m telescope with a science-grade ALADDIN array.

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

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

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

  11. A Hubble Space Telescope Survey of Extended [O III] λ5007 Emission in a Far-Infrared Selected Sample of Seyfert Galaxies: Observations

    NASA Astrophysics Data System (ADS)

    Schmitt, H. R.; Donley, J. L.; Antonucci, R. R. J.; Hutchings, J. B.; Kinney, A. L.

    2003-10-01

    We present a Hubble Space Telescope (HST) survey of extended [O III] emission for a sample of 60 Seyfert galaxies (22 Seyfert 1 galaxies and 38 Seyfert 2 galaxies), selected based on their far-infrared properties. The observations for 42 of these galaxies were done in a snapshot survey with WFPC2. The remaining 18 were obtained from the HST archive, most of which were observed with the same configuration. These observations cover 68% of the objects in the sample defined by Kinney et al. and create a valuable data set for the study of the narrow-line region (NLR) properties of Seyfert galaxies. In this paper, we present the details of the observations, reductions, and measurements. We also discuss the extended structure of individual sources, and the relation of this emission to the radio and host galaxy morphology. We also address how representative the subsample of [O III]-imaged galaxies is of the entire sample, and possible selection effects that may affect this comparison of the properties of Seyfert 1 and Seyfert 2 galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  12. Imaging interferometric microscopy.

    PubMed

    Schwarz, Christian J; Kuznetsova, Yuliya; Brueck, S R J

    2003-08-15

    We introduce and demonstrate a new microscopy concept: imaging interferometric microscopy (IIM), which is related to holography, synthetic-aperture imaging, and off-axis-dark-field illumination techniques. IIM is a wavelength-division multiplex approach to image formation that combines multiple images covering different spatial-frequency regions to form a composite image with a resolution much greater than that permitted by the same optical system using conventional techniques. This new type of microscopy involves both off-axis coherent illumination and reinjection of appropriate zero-order reference beams. Images demonstrate high resolution, comparable with that of a high-numerical-aperture (NA) objective, while they retain the long working distance, the large depth of field, and the large field of view of a low-NA objective. A Fourier-optics model of IIM is in good agreement with the experiment. PMID:12943079

  13. Near-infrared transmission spectrum of the warm-Uranus GJ 3470b with the Wide Field Camera-3 on the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Ehrenreich, D.; Bonfils, X.; Lovis, C.; Delfosse, X.; Forveille, T.; Mayor, M.; Neves, V.; Santos, N. C.; Udry, S.; Ségransan, D.

    2014-10-01

    The atmospheric composition of super-Earths and Neptunes is the object of intense observational and theoretical investigations. Transmission spectra recently obtained for such exoplanets are featureless in the near infrared. This flat signature is attributed to the presence of optically-thick clouds or translucent hazes. The planet GJ 3470b is a warm Neptune (or Uranus) detected in transit across a bright late-type star. The transit of this planet has already been observed in several band passes from the ground and space, allowing observers to draw an intriguing yet incomplete transmission spectrum of the planet atmospheric limb. In particular, published data in the visible suggest the existence of a Rayleigh scattering slope - making GJ 3470b a unique case among the known Neptunes, while data obtained beyond 2 μm are consistent with a flat infrared spectrum. The unexplored near-infrared spectral region between 1 μm and 2 μm, is thus the key to understanding the atmospheric nature of GJ 3470b. Here, we report on the first space-borne spectrum of GJ 3470, obtained during one transit of the planet with the Wide Field Camera-3 (WFC3) on board the Hubble Space Telescope (HST), operated in stare mode. The spectrum covers the 1.1-1.7 μm region with a resolution of ~300 (Δλ ~ 4 nm). We retrieve the transmission spectrum of GJ 3470b with a chromatic planet-to-star radius ratio precision of 0.09% (about half a scale height) per 40 nm bins. At this precision, the spectrum appears featureless, in good agreement with ground-based and Spitzer infrared data at longer wavelengths, pointing to a flat transmission spectrum from 1 μm to 5 μm. We present new simulations of possible theoretical transmission spectra for GJ 3470b, which allow us to show that the HST/WFC3 observations rule out cloudless hydrogen-rich atmospheres (>10σ) as well as hydrogen-rich atmospheres with tholin haze (>5σ). Adding our near-infrared measurements to the full set of previously published data

  14. The LINC-NIRVANA Fizeau interferometric imager: final lab integration, first light experiments and challenges

    NASA Astrophysics Data System (ADS)

    Herbst, T. M.; Ragazzoni, R.; Eckart, A.; Weigelt, G.

    2014-07-01

    LINC-NIRVANA (LN) is an innovative Fizeau interferometric imager for the Large Binocular Telescope (LBT). LN uses Multi-Conjugate Adaptive Optics (MCAO) for high-sky-coverage single-eye imagery and interferometric beam combination. The last two years have seen both successes and challenges. On the one hand, final integration is proceeding well in the lab. We also achieved First Light at the LBT with the Pathfinder experiment. On the other hand, funding constraints have forced a significant re-planning of the overall instrument implementation. These laboratory, observatory, and financial "events" provide lessons for builders of complex interferometric instruments on large telescopes. This paper presents our progress and plans for bringing the instrument online at the telescope.

  15. First Detection of GeV Emission from an Ultraluminous Infrared Galaxy: Arp 220 as Seen with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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.

  16. The Collapse of the Wien Tail in the Coldest Brown Dwarf? Hubble Space Telescope Near-infrared Photometry of WISE J085510.83–071442.5

    NASA Astrophysics Data System (ADS)

    Schneider, Adam C.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.

    2016-06-01

    We present Hubble Space Telescope (HST) near-infrared photometry of the coldest known brown dwarf, WISE J085510.83‑071442.5 (WISE 0855‑0714). WISE 0855‑0714 was observed with the Wide Field Camera 3 (WFC3) on board HST using the F105W, F125W, and F160W filters, which approximate the Y, J, and H near-infrared bands. WISE 0855‑0714 is undetected at F105W with a corresponding 2σ magnitude limit of ∼26.9. We marginally detect WISE 0855‑0714 in the F125W images (S/N ∼ 4), with a measured magnitude of 26.41 ± 0.27, more than a magnitude fainter than the J-band magnitude reported by Faherty et al. WISE J0855‑0714 is clearly detected in the F160W band, with a magnitude of 23.86 ± 0.03, the first secure detection of WISE 0855‑0714 in the near-infrared. Based on these data, we find that WISE 0855‑0714 has extremely red {{F}}105{{W}}-{{F}}125{{W}} and {{F}}125{{W}}-{{F}}160{{W}} colors relative to other known Y dwarfs. We find that when compared to the models of Saumon et al. and Morley et al., the {{F}}105{{W}}-{{F}}125{{W}} and {{F}}125{{W}}-{{F}}160{{W}} colors of WISE 0855‑0714 cannot be accounted for simultaneously. These colors likely indicate that we are seeing the collapse of flux on the Wien tail for this extremely cold object.

  17. Terahertz interferometric imaging of RDX

    NASA Astrophysics Data System (ADS)

    Sinyukov, Alexander M.; Barat, Robert B.; Gary, Dale E.; Michalopoulou, Zoi-Heleni; Zorych, Ivan; Zimdars, David; Federici, John F.

    2007-04-01

    Experimental results of homodyne terahertz interferometric 2-D imaging of RDX are presented. Continuous waves at 0.25-0.6 THz are used to obtain images of a C-4 sample at several THz frequencies. The performance of an N element detector array is imitated by only one detector placed at N positions. The distance between the C-4 sample and the detector array is ~30 cm. By taking interferometric images at several THz frequencies RDX can be recognized by the spectral peak at 0.82 THz. Simulations of interferometric images of two point sources of spherical waves are presented. The terahertz interferometric imaging method can be used in defense and security applications to detect concealed weapons, explosives as well as chemical and biological agents.

  18. 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.

  19. 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). PMID:19458729

  20. Analysis of an interferometric Stokes imaging polarimeter

    NASA Astrophysics Data System (ADS)

    Murali, Sukumar

    Estimation of Stokes vector components from an interferometric fringe encoded image is a novel way of measuring the State Of Polarization (SOP) distribution across a scene. Imaging polarimeters employing interferometric techniques encode SOP in- formation across a scene in a single image in the form of intensity fringes. The lack of moving parts and use of a single image eliminates the problems of conventional polarimetry - vibration, spurious signal generation due to artifacts, beam wander, and need for registration routines. However, interferometric polarimeters are limited by narrow bandpass and short exposure time operations which decrease the Signal to Noise Ratio (SNR) defined as the ratio of the mean photon count to the standard deviation in the detected image. A simulation environment for designing an Interferometric Stokes Imaging polarimeter (ISIP) and a detector with noise effects is created and presented. Users of this environment are capable of imaging an object with defined SOP through an ISIP onto a detector producing a digitized image output. The simulation also includes bandpass imaging capabilities, control of detector noise, and object brightness levels. The Stokes images are estimated from a fringe encoded image of a scene by means of a reconstructor algorithm. A spatial domain methodology involving the idea of a unit cell and slide approach is applied to the reconstructor model developed using Mueller calculus. The validation of this methodology and effectiveness compared to a discrete approach is demonstrated with suitable examples. The pixel size required to sample the fringes and minimum unit cell size required for reconstruction are investigated using condition numbers. The importance of the PSF of fore-optics (telescope) used in imaging the object is investigated and analyzed using a point source imaging example and a Nyquist criteria is presented. Reconstruction of fringe modulated images in the presence of noise involves choosing an

  1. Interferometric synthetic aperture microscopy

    NASA Astrophysics Data System (ADS)

    Ralston, Tyler S.; Marks, Daniel L.; Scott Carney, P.; Boppart, Stephen A.

    2007-02-01

    State-of-the-art methods in high-resolution three-dimensional optical microscopy require that the focus be scanned through the entire region of interest. However, an analysis of the physics of the light-sample interaction reveals that the Fourier-space coverage is independent of depth. Here we show that, by solving the inverse scattering problem for interference microscopy, computed reconstruction yields volumes with a resolution in all planes that is equivalent to the resolution achieved only at the focal plane for conventional high-resolution microscopy. In short, the entire illuminated volume has spatially invariant resolution, thus eliminating the compromise between resolution and depth of field. We describe and demonstrate a novel computational image-formation technique called interferometric synthetic aperture microscopy (ISAM). ISAM has the potential to broadly impact real-time three-dimensional microscopy and analysis in the fields of cell and tumour biology, as well as in clinical diagnosis where in vivo imaging is preferable to biopsy.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. The 2010 interferometric imaging beauty contest

    NASA Astrophysics Data System (ADS)

    Malbet, Fabien; Cotton, William; Duvert, Gilles; Lawson, Peter; Chiavassa, Andrea; Young, John; Baron, Fabien; Buscher, David; Rengaswamy, Sridharan; Kloppenborg, Brian; Vannier, Martin; Mugnier, Laurent

    2010-07-01

    We present the results of the fourth Optical/IR Interferometry Imaging Beauty Contest. The contest consists of blind imaging of test data sets derived from model sources and distributed in the OI-FITS format. The test data consists of spectral data sets on an object "observed" in the infrared with spectral resolution. There were 4 different algorithms competing this time: BSMEM the Bispectrum Maximum Entropy Method by Young, Baron & Buscher; RPR the Recursive Phase Reconstruction by Rengaswamy; SQUEEZE a Markov Chain Monte Carlo algorithm by Baron, Monnier & Kloppenborg; and, WISARD theWeak-phase Interferometric Sample Alternating Reconstruction Device by Vannier & Mugnier. The contest model image, the data delivered to the contestants and the rules are described as well as the results of the image reconstruction obtained by each method. These results are discussed as well as the strengths and limitations of each algorithm.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. The Multiple Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Beckers, J. M.; Ulich, B. L.; Shannon, R. R.; Carleton, N. P.; Geary, J. C.; Latham, D. W.; Angel, J. R. P.; Hoffmann, W. F.; Low, F. J.; Weymann, R. J.

    The Multiple Mirror Telescope (MMT), located on top of Mount Hopkins (2600 m) in Arizona, consists of six main telescope systems, each of which is a classical Cassegrain with a 1.8 m diameter parabolic primary with focal ratio f/2.7, and a hyperbolic secondary producing a final f/31.6 for each of the individual telescopes. The most significant departures of the MMT from conventional optical telescope technology are (1) the use of light-weight 'egg-crate' mirrors, which reduced the telescope weight, (2) the use of an alt-azimuth mount, which simplifies the gravitational effects on the structure, (3) the use of a ball-bearing support rather than hydrostatic bearings, resulting in cost savings and less maintenance, (4) the use of spur gear drives rather than worm gears, and (5) the use of multiple coaligned light collectors rather than a single monolithic mirror. Early multiple objective telescopes are discussed, and the early history of the MMT project is given. The design and performance of the telescope are explained, and MMT instrumentation (spectrograph, optical design, detector, infrared photometer, SAO CCD camera) is given. Astronomical research with the telescope is discussed, along with plans for future multiple objective telescopes.

  17. Lear jet telescope system

    NASA Technical Reports Server (NTRS)

    Erickson, E. F.; Goorvitch, D.; Dix, M. G.; Hitchman, M. J.

    1974-01-01

    The telescope system was designed as a multi-user facility for observations of celestial objects at infrared wavelengths, where ground-based observations are difficult or impossible due to the effects of telluric atmospheric absorption. The telescope is mounted in a Lear jet model 24B which typically permits 70 min. of observing per flight at altitudes in excess of 45,000 ft (13 km). Telescope system installation is discussed, along with appropriate setup and adjustment procedures. Operation of the guidance system is also explained, and checklists are provided which pertain to the recommended safe operating and in-flight trouble-shooting procedures for the equipment.

  18. A Spitzer Space Telescope Far-infrared Spectral Atlas of Compact Sources in the Magellanic Clouds. II. The Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

    We present far-infrared spectra, λ = 52-93 μm, 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 μm) and N 84 both display strong [O I] λ63 μm and [O III] λ88 μm 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 in the LMC, ≈0

  19. Interferometric polarization control

    SciTech Connect

    Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey; Novak, Giles

    2006-07-20

    We develop the Jones and Mueller matrices for structures that allow control of the path length difference between two linear orthogonal polarizations and consider the effect of placing multiple devices in series. Specifically, we find that full polarization modulation (measurement of Stokes Q, U, and V) can be achieved by placing two such modulators in series if the relative angles of the beam-splitting grids with respect to the analyzer orientation are appropriately chosen. Such a device has several potential advantages over a spinning wave plate modulator for measuring astronomical polarization in the far infrared through millimeter: (i) The use of small, linear motions eliminates the need for cryogenic rotational bearings; (ii) the phase flexibility allows measurement of circular as well as linear polarization; and (iii) this architecture allows for both multiwavelength and broadband modulation. We also present initial laboratory results.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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:/...

  5. 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)

  6. 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.

  7. Interferometric Measurements Of The A-type Supergiant Deneb With The CHARA Array

    NASA Astrophysics Data System (ADS)

    Aufdenberg, Jason P.; Mérand, A.; Ridgway, S. T.; Coudé du Foresto, V.; Kervella, P.; Berger, D.; Sturmann, J.; Sturmann, L.; ten Brummelaar, T. A.; Turner, N. H.; McAlister, H. A.

    2006-06-01

    We have obtained precise interferometric measurements of the A-type supergiant Deneb (A2Ia) at the Center for High Angular Resolution Astronomy (CHARA) Array in the infrared K' band (1.94 to 2.34 microns) using the Fiber Linked Unit for Optical Recombination (FLUOR). Our observations were obtained over 20 nights in 2004 and 2005 with five telescope pairs E2-W2, W2-S2, W1-E2, E1-W1, and S1-W2. The projected baselines span 106 to 312 meters and sample the first and second lobes of Deneb's visibility curve. Our preliminary analysis reveals that the amplitude of the second lobe of the visibility curve is weaker than that predicted by a spherical hydrostatic model atmosphere.We also find that Deneb's angular diameter varies with position angle at the level of a few percent. We will present these data and discuss our analysis using a unified expanding model atmosphere and a rotationally distorted model atmosphere.This work was performed in part under contract with the Jet Propulsion Laboratory (JPL) funded by NASA through the Michelson Fellowship Program. JPL is managed for NASA by the California Institute of Technology. The CHARA Array is operated by the Center for High Angular Resolution Astronomy, Georgia State University, Atlanta, GA. Additional support comes from the National Science Foundation, the Keck Foundation and the Packard Foundation.

  8. 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

  9. Overview of instrumentation for the large binocular telescope

    NASA Astrophysics Data System (ADS)

    Wagner, Robert M.

    2003-03-01

    An overview of the 3 facility instruments and 2 strategic interferometric instruments under construction for the Large Binocular Telescope is presented. Planned optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (25' x 25') UB/VRI optimized mosaic CCD imagers at the prime focus, and the MultiObject Double Spectrograph (MODS), a pair of dual-beam blue-red optimized longslit spectrographs mounted at the straight-through F/15 Gregorian focus incorporating multiple slit masks for multi-object spectroscopy over a 5' field and spectral resolutions of 2000-8000. 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') and diffraction limited (FOV: 0.5' x 0.5') imaging and longslit spectroscopy, seeing limited multiobject spectroscopy utilizing cooled slit masks, and optional diffraction limited integral field spectroscopy. Strategic instruments under development for the remaining two combined focal stations include an interferometric cryogenic beam combiner with NIR and thermal IR instruments for Fizeau imaging and nulling interferometry and an optical bench beam combiner with visible and NIR imagers utilizing in the future multi-conjugate adaptive optics for angular resolutions as high as 5 mas at a wavelength of 0.5 μm. The availability of all these instruments mounted simultaneously on the LBT permits flexible scheduling and improved operational support.

  10. 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.

  11. Interferometric seismoelectric Green's function representations

    NASA Astrophysics Data System (ADS)

    de Ridder, Sjoerd A. L.; Slob, Evert; Wapenaar, Kees

    2009-09-01

    Interferometric Green's function representations can be used to retrieve a Green's function between two receiver stations, effectively turning one receiver into a source. Through reciprocity theorems of the convolution and correlation types, we derive interferometric Green's function representations for coupled electromagnetic and seismic wave propagation in 1-D. These representations express a symmetrized Green's function in terms of correlations of sources distributed throughout the domain of reciprocity and on its boundary. The main challenge for practical implementation is the necessity of sources throughout a domain. Numerical examples show how this constraint can be relaxed for different configurations. In a configuration of two layers bounded by a vacuum, seismic noise sources behind the interface can be used to recover seismoelectric reflection responses that suffer from small amplitude losses, but are not corrupted by spurious events.

  12. 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.

  13. Interferometric array layout design by tomographic projection

    NASA Astrophysics Data System (ADS)

    de Villiers, M.

    2007-07-01

    Context: This study pertains to the optimization of the layout of a single configuration interferometric array to achieve a desired natural tapering for the density distribution of its UV plane coverage. Existing techniques that seek this goal determine a two dimensional density gradient that acts on the UV samples and in turn on the antenna positions. This gradient is commonly computed by gridding the UV plane, and is sometimes averaged over a number of different scales due to the sparseness of the UV samples. Aims: The goal of this study is to demonstrate a new method that can move antenna positions to achieve an ideal density distribution for the UV samples without the need for gridding. Methods: An approach is described where the UV samples are projected into a one dimensional vector. If an equivalent projection is done for an ideal model distribution, the difference between these vectors yields correction terms which can be mapped to new antenna positions. Such modifications are made in all directions until a close match is achieved to the desired UV plane coverage and equivalently, by the Fourier transform, the ideal point spread function. Results: Results are provided that relate achievable resolution (for Gaussian UV coverage) to the number of antennas available to the algorithm, for a few different observation modes. Preliminary layouts are shown for the Square Kilometer Array pathfinder project, the Karoo Array Telescope. Conclusions: The proposed method is applicable to very few as well as a large number of antennas. Multiple objective optimization is not considered.

  14. From 1.5 Meters to 10.4 Meters in 20 Years: Technological Evolution at the Instituto de Astrofísica de Canarias in the Development of Infrared Instrumentation for Terrestrial Telescopes

    NASA Astrophysics Data System (ADS)

    Caicoya, P. G. R.; Cabrera, M. B.; Izquierdo, P. F.; Patrón, J.; Sánchez de La Rosa, V.; Sangines, F. T.

    This paper reviews the evolution of the technical development of infrared instrumentation for terrestrial telescopes at the Instituto de Astrofísica de Canarias (IAC). The three most representative instruments, CAIN (installed on the 1.5 m Carlos Sánchez Telescope), LIRIS (on the 4.2 m William Herschel Telescope), and EMIR (on the 10.4 m Gran Telescopio Canarias) are described and compared. Each project entailed an improvement and a technological advance in relation to its predecessor. Larger optical beams brought larger lenses, larger mechanisms to hold them, stiffer and more massive support structures, and a scale factor upgrade of their cryostats. The evolution of infrared projects has been closely linked to the development of the manufacturing, assembly, integration and verification facilities at the IAC and has also had a strong influence on management techniques. As an indication of the growth in complexity of projects over time, this paper highlights the framework of available human resources, established consortia, timing and costs associated with the three instruments.

  15. Interferometric observation of microlensing events

    NASA Astrophysics Data System (ADS)

    Cassan, Arnaud; Ranc, Clément

    2016-05-01

    Interferometric observations of microlensing events have the potential to provide unique constraints on the physical properties of the lensing systems. In this work, we first present a formalism that closely combines interferometric and microlensing observable quantities, which lead us to define an original microlensing (u, v) plane. We run simulations of long-baseline interferometric observations and photometric light curves to decide which observational strategy is required to obtain a precise measurement on vector Einstein radius. We finally perform a detailed analysis of the expected number of targets in the light of new microlensing surveys (2011+) which currently deliver 2000 alerts per year. We find that a few events are already at reach of long-baseline interferometers (CHARA, VLTI), and a rate of about six events per year is expected with a limiting magnitude of K ≃ 10. This number would increase by an order of magnitude by raising it to K ≃ 11. We thus expect that a new route for characterizing microlensing events will be opened by the upcoming generations of interferometers.

  16. Radar Interferometric Imaging of Near-Earth Asteroids

    NASA Astrophysics Data System (ADS)

    Margot, J. L.; Nolan, M. C.

    1999-09-01

    High resolution imagery and a three-dimensional characterization of Near-Earth Asteroids (NEAs) can be obtained with ground-based radars. The Arecibo and Goldstone radar systems yield data at spatial resolutions comparable to the highest resolution spacecraft images of asteroids obtained to date. The use of radar interferometry techniques can further improve imaging and shape reconstruction algorithms [1],[2] and may allow direct measurements of the topography of NEAs. A two-element radar interferometer of appropriate baseline provides an observable, the interferometric phase, which can be used to extract three-dimensional information about the target [3], hence giving additional control in shape modeling procedures. The measurement of interferometric phase also opens the possibility of mapping the topography of an asteroid, in a manner similar to that applied recently to the Moon [4]. Simulations show that this is feasible when potential ambiguities in range-Doppler imaging are avoided, for instance when elongated objects are in a favorable orientation. Radar interferometric imaging of 6489 Golevka was attempted during its June 1999 close approach to Earth [5]. The Arecibo 305 m telescope was used to transmit, and the DSN 70 m antenna in Madrid formed the second element of the interferometer. The Arecibo-Madrid baseline defined an ideal fringe pattern for interferometric mapping, but technical difficulties prevented imaging of the Madrid data. Radar interferometry concepts and simulation results will be presented, as well as any new data acquired before the meeting. [1] R. S. Hudson and S. J. Ostro (1994). Science, 263, 940. [2] R. S. Hudson and S. J. Ostro (1995). Science, 270, 84. [3] I. I. Shapiro et al. (1972). Science, 178, 939. [4] J. L. Margot et al. (1999). Science, 284, 1658. [5] J. L. Margot and M. C. Nolan (1999). ACM Meeting, July 26-30, Cornell University, Ithaca, NY.

  17. 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.

  18. 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.

  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.

    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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. A thermal spectral-spatial interferometric testbed

    NASA Astrophysics Data System (ADS)

    Savini, G.; Juanola-Parramon, R.; Stabbins, R.; Baccichet, N.; Donohoe, A.; Murphy, A.; O'Sullivan, C.

    2014-07-01

    We present an ongoing effort to achieve a Double Fourier Modulating (DFM) interferometer in the thermal infrared wavelength range. We describe a testbed designed to combine a sky simulator in the form of a miniaturized complex calibration source at the focus of a parabolic collimator with an interferometer baseline consisting of two parallel telescopes each mounted on a motorized linear stage. The two input arms are combined after one of them is modulated via a fast-scanning piezoelectric roof-top mirror. The optical design and layout of the testbed, the choice of interferometer parameters as well as the calibration scene adopted as source are described.

  7. Wide-Angle, Flat-Field Telescope

    NASA Technical Reports Server (NTRS)

    Hallam, K. L.; Howell, B. J.; Wilson, M. E.

    1987-01-01

    All-reflective system unvignetted. Wide-angle telescope uses unobstructed reflecting elements to produce flat image. No refracting elements, no chromatic aberration, and telescope operates over spectral range from infrared to far ultraviolet. Telescope used with such image detectors as photographic firm, vidicons, and solid-state image arrays.

  8. 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

  9. 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

  10. The Information Content of Interferometric Synthetic Aperture Radar: Vegetation and Underlying Surface Topography

    NASA Technical Reports Server (NTRS)

    Treuhaft, Robert N.

    1996-01-01

    This paper first gives a heuristic description of the sensitivity of Interferometric Synthetic Aperture Radar to vertical vegetation distributions and underlying surface topography. A parameter estimation scenario is then described in which the Interferometric Synthetic Aperture Radar cross-correlation amplitude and phase are the observations from which vegetation and surface topographic parameters are estimated. It is shown that, even in the homogeneous-layer model of the vegetation, the number of parameters needed to describe the vegetation and underlying topography exceeds the number of Interferometric Synthetic Aperture Radar observations for single-baseline, single-frequency, single-incidence-angle, single-polarization Interferometric Synthetic Aperture Radar. Using ancillary ground-truth data to compensate for the underdetermination of the parameters, forest depths are estimated from the INSAR data. A recently-analyzed multibaseline data set is also discussed and the potential for stand-alone Interferometric Synthetic Aperture Radar parameter estimation is assessed. The potential of combining the information content of Interferometric Synthetic Aperture Radar with that of infrared/optical remote sensing data is briefly discussed.

  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. Optomechanical spectroscopy with broadband interferometric and quantum cascade laser sources

    SciTech Connect

    Tetard, Laurene; Passian, Ali; Farahi, R H; Davison, Brian H; Thundat, Thomas George

    2011-01-01

    The spectral tunability of semiconductor-metal multilayer structures can provide a channel for the conversion of light into useful mechanical actuation. Response of suspended silicon, silicon nitride, chromium, gold, and aluminum microstructures is shown to be utilized as a detector for visible and infrared spectroscopy. Both dispersive and interferometric approaches are investigated to delineate the potential use of the structures in spatially resolved spectroscopy and spectrally resolved microscopy. The thermoplasmonic, spectral absorption, interference effects, and the associated energy deposition that contributes to the mechanical response are discussed to describe the optomechanical detection to be of potential importance in future integrated spectrometers.

  15. Interferometric optical vortex array generator.

    PubMed

    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. PMID:17514234

  16. 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.

  17. Interferometric monitoring of dip coating

    NASA Astrophysics Data System (ADS)

    Michels, Alexandre F.; Menegotto, Thiago; Horowitz, Flavio

    2004-02-01

    Dip-coated films, which are widely used in the coating industry, are usually measured by capacitive methods with micrometric precision. For the first time to our knowledge, we have applied an interferometric determination of the evolution of thickness in real time to nonvolatile Newtonian mineral oils with several viscosities and distinct dip withdrawing speeds. The evolution of film thickness during the process depends on time as t-1/2, in accordance with a simple model. Comparison with measured results with an uncertainty of +/-0.007 μm) showed good agreement after the initial steps of the process had been completed.

  18. Decorrelation in interferometric radar echoes

    NASA Technical Reports Server (NTRS)

    Zebker, Howard A.; Villasensor, John

    1992-01-01

    A radar interferometric technique for topographic mapping of surfaces promises a high resolution, globally consistent approach to generation of digital elevation models. One implementation approach, that of utilizing a single SAR system in a nearly repeating orbit, is attractive not only for cost and complexity reasons but also in that it permits inference of changes in the surface over the orbit repeat cycle from the correlation properties of the radar echoes. The various sources contributing to the echo correlation statistics are characterized, and the term which most closely describes surficial change is isolated. There is decorrelation increasing with time, but digital terrain model generation remains feasible.

  19. Frequency modulated lasers for interferometric optical gyroscopes.

    PubMed

    Komljenovic, Tin; Tran, Minh A; Belt, Michael; Gundavarapu, Sarat; Blumenthal, Daniel J; Bowers, John E

    2016-04-15

    We study the use of frequency modulated lasers in interferometric optical gyroscopes and show that by exploiting various frequency modulation signals, the laser coherence can be controlled. We show that both angle random walk and bias stability of an interferometric optical gyroscope based on laser sources can be improved with this technique. PMID:27082342

  20. 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. PMID:21643113

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. GRAVITY: a four-telescope beam combiner instrument for the VLTI

    NASA Astrophysics Data System (ADS)

    Gillessen, S.; Eisenhauer, F.; Perrin, G.; Brandner, W.; Straubmeier, C.; Perraut, K.; Amorim, A.; Schöller, M.; Araujo-Hauck, C.; Bartko, H.; Baumeister, H.; Berger, J.-P.; Carvas, P.; Cassaing, F.; Chapron, F.; Choquet, E.; Clenet, Y.; Collin, C.; Eckart, A.; Fedou, P.; Fischer, S.; Gendron, E.; Genzel, R.; Gitton, P.; Gonte, F.; Gräter, A.; Haguenauer, P.; Haug, M.; Haubois, X.; Henning, T.; Hippler, S.; Hofmann, R.; Jocou, L.; Kellner, S.; Kervella, P.; Klein, R.; Kudryavtseva, N.; Lacour, S.; Lapeyrere, V.; Laun, W.; Lena, P.; Lenzen, R.; Lima, J.; Moratschke, D.; Moch, D.; Moulin, T.; Naranjo, V.; Neumann, U.; Nolot, A.; Paumard, T.; Pfuhl, O.; Rabien, S.; Ramos, J.; Rees, J. M.; Rohloff, R.-R.; Rouan, D.; Rousset, G.; Sevin, A.; Thiel, M.; Wagner, K.; Wiest, M.; Yazici, S.; Ziegler, D.

    2010-07-01

    GRAVITY is an adaptive optics assisted Beam Combiner for the second generation VLTI instrumentation. The instrument will provide high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the astronomical K-band for faint objects. We describe the wide range of science that will be tackled with this instrument, highlighting the unique capabilities of the VLTI in combination with GRAVITY. The most prominent goal is to observe highly relativistic motions of matter close to the event horizon of Sgr A*, the massive black hole at center of the Milky Way. We present the preliminary design that fulfils the requirements that follow from the key science drivers: It includes an integrated optics, 4-telescope, dual feed beam combiner operated in a cryogenic vessel; near-infrared wavefrontsensing adaptive optics; fringe-tracking on secondary sources within the field of view of the VLTI and a novel metrology concept. Simulations show that 10 μas astrometry within few minutes is feasible for a source with a magnitude of mK = 15 like Sgr A*, given the availability of suitable phase reference sources (mK = 10). Using the same setup, imaging of mK = 18 stellar sources in the interferometric field of view is possible, assuming a full night of observations and the corresponding UV coverage of the VLTI.

  6. 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

  7. Multifocal interferometric synthetic aperture microscopy.

    PubMed

    Xu, Yang; Chng, Xiong Kai Benjamin; Adie, Steven G; Boppart, Stephen A; Carney, P Scott

    2014-06-30

    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

  8. Source Detection with Interferometric Datasets

    NASA Astrophysics Data System (ADS)

    Trott, Cathryn M.; Wayth, Randall B.; Macquart, Jean-Pierre R.; Tingay, Steven J.

    2012-04-01

    The detection of sources in interferometric radio data typically relies on extracting information from images, formed by Fourier transform of the underlying visibility dataset, and CLEANed of contaminating sidelobes through iterative deconvolution. Variable and transient radio sources span a large range of variability timescales, and their study has the potential to enhance our knowledge of the dynamic universe. Their detection and classification involve large data rates and non-stationary PSFs, commensal observing programs and ambitious science goals, and will demand a paradigm shift in the deployment of next-generation instruments. Optimal source detection and classification in real time requires efficient and automated algorithms. On short time-scales variability can be probed with an optimal matched filter detector applied directly to the visibility dataset. This paper shows the design of such a detector, and some preliminary detection performance results.

  9. The Chinese Giant Solar Telescope

    NASA Astrophysics Data System (ADS)

    Liu, Zhong; Deng, Yuanyong; Ji, Haisheng

    2014-01-01

    Chinese Giant Solar Telescope is the next generation ground-based solar telescope. The main science task of this telescope is to observe the ultra fine structures of the solar magnetic field and dynamic field. Due to the advantages in polarization detection and thermal controlling with a symmetrical circular system, the current design of CGST is a 6~8 meter circular symmetrical telescope. The results of simulations and analysis showed that the current design could meet the demands of most science cases not only in infrared bands but also in near infrared bands and even in visible bands. The prominences and the filaments are very important science cases of CGST. The special technologies for prominence observation will be developed, including the day time laser guide star and MCAO. CGST is proposed by all solar observatories and several institutes and universities in China. It is supported by CAS and NSFC (National Natural Science Foundation of China) as a long term astronomical project.

  10. Seventeenth-century telescope optics of Torricelli, Divini, and Campani

    NASA Astrophysics Data System (ADS)

    Miniati, Mara; van Helden, Albert; Greco, Vincenzo; Molesini, Giuseppe

    2002-02-01

    Optics of telescope makers Torricelli, Divini, and Campani dating back to the 17th century have been tested interferometrically. It was found that the optical polishing technology had progressed to thorough control over the surface figure and finish, while the nearly paraxial conditions of the aperture remained constant. The instruments that were examined exemplify the knowledge of optics of that time, particularly with respect to the early use of erector units in terrestrial telescopes.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Infrared Observations of Ongoing Star Formation in the 30 Doradus Nebula and a Comparison with Hubble Space Telescope WFPC 2 Images

    NASA Astrophysics Data System (ADS)

    Rubio, Mónica; Barbá, Rodolfo H.; Walborn, Nolan R.; Probst, Ronald G.; García, Jorge; Roth, Miguel R.

    1998-10-01

    Intercomparisons of ground-based IR continuum and H_2 images with Hubble Space Telescope WFPC2 images of the 30 Dor Nebula reveal detailed structural relationships, which provide new information about current star formation there. Numerous stellar IR sources have been discovered in or near the bright nebular filaments west and northeast of R136; their locations are intimately connected with the nebular microstructures, as well as with early O stars in dense nebular knots whose optical spectral classifications indicate extreme youth. The H_2 emission predominates in the dust clouds beyond the bright nebulosity and IR sources with respect to R136. The emerging picture suggests that a new stellar generation is being triggered by the energetic activity of the massive central cluster in the remanent interstellar material around its periphery. 30 Dor will likely evolve into a giant shell H ii region similar to N11 in the LMC, containing an older association inside an evacuated central cavity, which is surrounded by H ii regions ionized by a younger population. Such ``two-stage starbursts'' may be characteristic of massive-star formation on this scale. Based in part on observations with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 5-26555.

  16. Terahertz interferometric imaging of a concealed object

    NASA Astrophysics Data System (ADS)

    Sinyukov, Alexander M.; Bandyopadhyay, Aparajita; Sengupta, Amartya; Barat, Robert B.; Gary, Dale E.; Michalopoulou, Zoi-Heleni; Zimdars, David; Federici, John F.

    2006-10-01

    Experimental results of two-dimensional homodyne terahertz interferometric imaging are presented. The performance of an N element detector array is imitated by only one detector placed at N positions. Continuous waves at 0.25-0.3 THz are used to detect concealed objects: a metal object and an RDX sample. The terahertz interferometric imaging method can be used in defense and security applications to detect concealed weapons, explosives as well as chemical and biological agents.

  17. Space Telescopes

    NASA Technical Reports Server (NTRS)

    Rigby, Jane R.

    2011-01-01

    The science of astronomy depends on modern-day temples called telescopes. Astronomers make pilgrimages to remote mountaintops where these large, intricate, precise machines gather light that rains down from the Universe. Bit, since Earth is a bright, turbulent planet, our finest telescopes are those that have been launched into the dark stillness of space. These space telescopes, named after heroes of astronomy (Hubble, Chandra, Spitzer, Herschel), are some of the best ideas our species has ever had. They show us, over 13 billion years of cosmic history, how galaxies and quasars evolve. They study planets orbiting other stars. They've helped us determine that 95% of the Universe is of unknown composition. In short, they tell us about our place in the Universe. The next step in this journey is the James Webb Space Telescope, being built by NASA, Europe, and Canada for a 2018 launch; Webb will reveal the first galaxies that ever formed.

  18. 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)

  19. 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.

  20. 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.

  1. C2PU: 1-Meter Telescopes for the GAIA-FUN

    NASA Astrophysics Data System (ADS)

    Bendjoya, Ph.; Abe, L.; Rivet, J. P.

    2011-06-01

    C2PU stands in french for "Centre Pédagogique Planète Univers" (Planet and Universe Pedagogic Center). It is a project both for pedagogic and research purposes. It relies on the renewal of two 1-meter diameter telescopes. These two telescopes were earlier coupled as part of an interferometric instrument called SOIRDETE (for "Synthèse d'Ouverture en Infra Rouge avec DEux Telescopes"), described in Rabbia et al. 1990.

  2. 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.

  3. Infrared astronomy takes center stage

    SciTech Connect

    Gillett, F.C.; Gatley, I.; Hollenbach, D. NASA, Ames Research Center, Moffett Field, CA )

    1991-08-01

    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.

  4. γ^2 Velorum: combining interferometric observations with hydrodynamic simulations

    NASA Astrophysics Data System (ADS)

    Lamberts, A.; Millour, F.

    2015-12-01

    Colliding stellar winds in massive binary systems have been studied through their radio and strong X-ray emission for decades. More recently, spectro-interferometric observations in the near infrared have become available for certain binaries, but identifying the different contributions to the emission remains a challenge. Multidimensional hydrodynamic simulations reveal a complex double shocked structure and can guide the analysis of observational data. In this work, we analyse the wind collision region in the WR+O binary, γ^2 Velorum. We combine multi-epoch AMBER observations with mock data obtained with hydrodynamic simulations with the RAMSES code. We assess the contributions of the wind collision region in order to constrain the wind structure of both stars.

  5. An Interferometric Search for Bright Companions to 51 Pegasi

    NASA Astrophysics Data System (ADS)

    Boden, A. F.; van Belle, G. T.; Colavita, M. M.; Dumont, P. J.; Gubler, J.; Koresko, C. D.; Kulkarni, S. R.; Lane, B. F.; Mobley, D. W.; Shao, M.; Wallace, J. K.; PTI Collaboration

    1998-09-01

    We report on a near-infrared, long-baseline interferometric search for luminous companions to the star 51 Pegasi conducted with the Palomar Testbed Interferometer. Our data is completely consistent with a single-star hypothesis. We find no evidence to suggest a luminous companion to 51 Pegasi, and we can exclude a companion brighter than a ΔK of 4.27 at the 99% confidence level for the 4.2 day orbital period indicated by spectroscopic measurements. This ΔK corresponds to an upper limit in the companion MK of 7.30, which in turn implies a main-sequence companion mass of less than 0.22 Msolar.

  6. 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…

  7. Achieving stabilization in interferometric logic operations.

    PubMed

    Zavalin, Andrey I; Shamir, Joseph; Vikram, Chandra S; Caulfield, H John

    2006-01-10

    Interferometric systems with amplitude beam splitters can implement reversible operations that, on detection, become Boolean operators. Being passive, they consume no energy, do not limit the operating bandwidth, and have negligible latency. Unfortunately, conventional interferometric systems are notoriously sensitive to uncontrolled disturbances. Here the use of polarization in a common-path interferometric logic gate with and without polarization beam splitters is explored as an attractive alternative to overcome those difficulties. Two of three device configurations considered offer significant stability and lower drive modulator voltage as advantages over the previous systems. The first experimental tests of such a system are reported. Common-path interferometry lends itself to even more stability and robustness by compatibility with no-air-gap, solid optics. PMID:16422166

  8. Achieving stabilization in interferometric logic operations

    NASA Astrophysics Data System (ADS)

    Zavalin, Andrey I.; Shamir, Joseph; Vikram, Chandra S.; Caulfield, H. John

    2006-01-01

    Interferometric systems with amplitude beam splitters can implement reversible operations that, on detection, become Boolean operators. Being passive, they consume no energy, do not limit the operating bandwidth, and have negligible latency. Unfortunately, conventional interferometric systems are notoriously sensitive to uncontrolled disturbances. Here the use of polarization in a common-path interferometric logic gate with and without polarization beam splitters is explored as an attractive alternative to overcome those difficulties. Two of three device configurations considered offer significant stability and lower drive modulator voltage as advantages over the previous systems. The first experimental tests of such a system are reported. Common-path interferometry lends itself to even more stability and robustness by compatibility with no-air-gap, solid optics.

  9. 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

  10. Imaging through scattering media by interferometric techniques

    NASA Astrophysics Data System (ADS)

    Tai, A. M.; Aleksoff, C. C.; Chang, B. J.

    1981-07-01

    It is shown that while holographic techniques are effective in seeing through such scattering media as fog, their usefulness in field applications is limited by the requirement of a separate reference beam. An alternative interferometric technique that uses a grating interferometric imaging system is presented, whose main advantage is a relatively high tolerance to normal vibration and air disturbances. It is proposed that the system incorporate a recording device that combines an image converter-intensifier with a real time light modulator. In addition to permitting real time operation, such a device would also increase system sensitivity and permit the use of IR illumination.

  11. Terahertz interferometric and synthetic aperture imaging

    NASA Astrophysics Data System (ADS)

    Sinyukov, Alexander M.; Bandyopadhyay, Aparajita; Sengupta, Amartya; Barat, Robert B.; Gary, Dale E.; Michalopoulou, Zoi-Heleni; Zimdars, David; Federici, John F.

    2006-05-01

    Experimental results of homodyne terahertz interferometric 1-D and 2-D imaging are presented. Continuous waves at 0.25-0.3 THz are used to detect a metal object behind a barrier. The performance of an N element detector array is imitated by only one detector placed at N positions. The reconstructed images are in a good agreement with theoretical predictions. The terahertz interferometric imaging method can be used in defense and security applications to detect concealed weapons, explosives as well as chemical and biological agents.

  12. 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.

  13. Trade-off study for high resolution spectroscopy in the near infrared with ELT telescopes: seeing-limited vs. diffraction limited instruments

    NASA Astrophysics Data System (ADS)

    Sanna, Nicoletta; Oliva, E.; Massi, Fabrizio; Cresci, G.; Origlia, L.

    2014-08-01

    HIRES, a high resolution spectrometer, is one of the first five instruments foreseen in the ESO roadmap for the E-ELT. This spectrograph should ideally provide full spectral coverage from the UV limit to 2.5 microns, with a resolving power from R˜10,000 to R˜100,000. At visual/blue wavelengths, where the adaptive optics (AO) cannot provide an efficient light-concentration, HIRES will necessarily be a bulky, seeing-limited instrument. The fundamental question, which we address in this paper, is whether the same approach should be adopted in the near-infrared range, or HIRES should only be equipped with compact infrared module(s) with a much smaller aperture, taking advantage of an AO-correction. The main drawbacks of a seeing-limited instrument at all wavelengths are: i) Lower sensitivities at wavelengths dominated by thermal background (red part of the K-band). ii) Much higher volumes and costs for the IR spectrograph module(s). The main drawbacks of using smaller, AO-fed IR module(s) are: i) Performances rapidly degrading towards shorter wavelengths (especially J e Y bands). ii) Different spatial sampling of extended objects (the optical module see a much larger area on the sky). In this paper we perform a trade-off analysis and quantify the various effects that contribute to improve or deteriorate the signal to noise ratio. In particular, we evaluate the position of the cross-over wavelength at which AO-fed instruments starts to outperform seeing-limited instruments. This parameter is of paramount importance for the design of the part of HIRES covering the K-band.

  14. 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.

  15. Perception for a large deployable reflector telescope

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. M.; Swanson, P. N.; Meinel, A. B.; Meinel, M. P.

    1984-01-01

    Optical science and technology concepts for a large deployable reflector for far-infrared and submillimeter astronomy from above the earth's atmosphere are discussed. Requirements given at the Asilomar Conference are reviewed. The technical challenges of this large-aperture (about 20-meter) telescope, which will be diffraction limited in the infrared, are highlighted in a brief discussion of one particular configuration.

  16. Optical aperture synthesis with electronically connected telescopes.

    PubMed

    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

  17. 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

  18. 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.

  19. 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.

  20. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Clampin, Mark

    2011-01-01

    The James Webb Space Telescope (JWST) is a large, infrared-optimized space telescope. JWST's primary science goal is to detect and characterize the first galaxies. It will also study the assembly of galaxies, star formation, and the formation of evolution of planetary systems. The observatory has a large primary mirror 6.5 meter in diameter, designed to deliver high angular resolution in the infrared, combined with a large collecting area. The telescope optics are designed and fabricated to operate at the cryogenic temperatures (,...,40 k) required for an IR optimized telescope. The primary mirror is also a segmented mirror architecture. The observatory is designed to achieve cryogenic operating temperature via passive cooling, facilitated by a five-layer sunshield which keeps the telescope in the sun's shadow. Since the observatory dimensions exceed the Ariane 5 fairing size, the observatory has to be stowed for launch and deployed following launch. The observatory will be launched into an L2 orbit that provides continuous science operations and a benign thermal environment for optical stability.

  1. The Smiley Radio Telescope

    NASA Astrophysics Data System (ADS)

    Blake, R. M.; Castelaz, M. W.; Daugherty, J.; Owen, L.

    2004-12-01

    More than ever modern astronomy is based upon a multi-wavelength approach combining data-sets from optical, infrared, radio, X-ray and gamma ray observatories to provide improved understanding of astrophysical phenomena. In the field of astronomy education however, until recently most teaching resources available to high schools have been limited to small optical telescopes, with little coverage of other branches of observational astronomy. To fill in this resource gap, PARI has developed the School of Galactic Radio Astronomy and the Smiley 4.6 m Radio Telescope to provide high schools access to a state-of-the-art, internet accessable radio observatory for class projects and activities. We describe here the development of the Smiley radio telescope, its control systems and give examples of several class activities which have been developed for use by high school students. We describe the future development of Smiley and plans to upgrade its performance. The SGRA has been supported by grants from Progress Energy, Z. Smith Reynolds, STScI IDEAS, and the AAS Small Research Grant Program which is supported by NASA.

  2. 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.

  3. 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.

  4. Calibration of mixed-polarization interferometric observations. Tools for the reduction of interferometric data from elements with linear and circular polarization receivers

    NASA Astrophysics Data System (ADS)

    Martí-Vidal, I.; Roy, A.; Conway, J.; Zensus, A. J.

    2016-03-01

    Heterodyne receivers register the sky signal on either a circular polarization basis (where it is split into left-hand and right-hand circular polarization) or a linear polarization basis (where it is split into horizontal and vertical linear polarization). We study the problem of interferometric observations performed with telescopes that observe on different polarization bases, hence producing visibilities that we call "mixed basis" (i.e., linear in one telescope and circular in the other). We present novel algorithms for the proper calibration and treatment of such interferometric observations and test our algorithms with both simulations and real data. The use of our algorithms will be important for the optimum calibration of forthcoming observations with the Atacama Large Mm/submm Array (ALMA) in very-long-baseline interferometry (VLBI) mode. Our algorithms will also allow us to optimally calibrate future VLBI observations at very high data rates (i.e., wide bandwidths), where linear-polarization feeds will be preferable at some stations, to overcome the polarimetric limitations due to the use of quarter-wave plates.

  5. 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.

  6. 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/. PMID:17503900

  7. Performance of the Multi-Spectral Solar Telescope Array. III - Optical characteristics of the Ritchey-Chretien and Cassegrain telescopes

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Baker, Phillip C.; Hadaway, James B.; Johnson, R. B.; Peterson, Cynthia; Gabardi, David R.; Walker, Arthur B., Jr.; Lindblom, J. F.; Deforest, Craig; O'Neal, R. H.

    1991-01-01

    The Multi-Spectral Solar Telescope Array (MSSTA), which is a sounding-rocket-borne observatory for investigating the sun in the soft X-ray/EUV and FUV regimes of the electromagnetic spectrum, utilizes single reflection multilayer coated Herschelian telescopes for wavelengths below 100 A, and five doubly reflecting multilayer coated Ritchey-Chretien and two Cassegrain telescopes for selected wavelengths in the EUV region between 100 and 1000 A. The paper discusses the interferometric alignment, testing, focusing, visible light testing, and optical performance characteristics of the Ritchey-Chretien and Cassegrain telescopes of MSSTA. A schematic diagram of the MSSTA Ritchey-Chretien telescope is presented together with diagrams of the system autocollimation testing.

  8. Damage Assessment Map from Interferometric Coherence

    NASA Astrophysics Data System (ADS)

    Yun, S.; Fielding, E. J.; Simons, M.; Rosen, P. A.; Owen, S. E.; Webb, F.

    2010-12-01

    Large earthquakes cause buildings to collapse, which often claims the lives of many. For example, 2010 Haiti earthquake killed about 230,000 people, with about 280,000 buildings collapsed or severely damaged. When a major earthquake hits an urban area, one of the most critical information for rescue operations is rapid and accurate assessment of building-collapse areas. From a study on 2003 Bam earthquake in Iran, interferometric coherence was proved useful for earthquake damage assessment (Fielding et al., 2005) when similar perpendicular baselines can be found for pre- and coseismic interferometric pairs and when there is little temporal and volume decorrelation. In this study we develop a new algorithm to create a more robust and accurate damage assessment map using interferometric coherence despite different interferometric baselines and with other decorrelation sources. We test the algorithm on a building block that recently underwent demolition, which is a proxy for building collapse due to earthquakes, for new construction in the City of Pasadena, California. The size of the building block is about 150 m E-W and 300 m N-S, and the demolition project started on April 23, 2007 and continued until January 22, 2008. After we process Japanese L-band ALOS PALSAR data with ROI_PAC, an interferometric coherence map that spans the demolition period is registered to a coherence map before the demolition, and the relative bias of the coherence values are removed, then a causality constraint is applied to enhance the change due to demolition. The results show clear change in coherence at the demolition site. We improve the signal-to-noise ratio of the coherence change at the demolition site from 17.3 (for simple difference) to 44.6 (with the new algorithm). The damage assessment map algorithm will become more useful with the emergence of InSAR missions with more frequent data acquisition, such as Sentinel-1 and DESDynI.

  9. NRO 10-m submillimeter telescope

    NASA Astrophysics Data System (ADS)

    Ukita, Nobuharu; Kawabe, Ryohei; Ishiguro, Masato; Ezawa, Hajime; Sekimoto, Yutaro; Hasegawa, Tatsuo; Yamamoto, Satoshi; Miyawaki, Keizo; Matsumoto, Soichi

    2000-07-01

    A 10-m submillimeter telescope designed for interferometric observations at bands from 3 to 0.3 mm has constructed at Nobeyama Radio Observatory. The telescope is an engineering model for a large millimeter and sub-millimeter array, and will be operated for developments of sub-millimeter observation techniques at a remote site. We have fabricated lightweight machined aluminum panels (15 kg m-2) that have a surface accuracy of 5 micrometer rms. They have a typical size of 0.8 m X 0.6 m, and are supported with three motorized screws. The back-up structure is constructed of a central hub of low thermal expansion alloy, and CFRP honeycomb boards and tubes. Holography measurements will be made with a nearby transmitter at 3 mm. The overall surface accuracy is expected to be < 25 micrometer rms; the goal being 17 micrometer rms. We have achieved an accuracy of 0.03' rms for angle encoders. The drive and control system is designed to achieve a pointing error of 1'.0 rms with no wind and at night. Under a wind velocity of 7 m s-1, the pointing error increases to 2'.0 rms. An optical telescope of 10-cm diameter mounted on the center hub will be used to characterize pointing and tracking accuracy. Thermal effects on the pointing and surface accuracy will be investigated using temperature measurements and FEM analyses. The fast position switching capability is also demanded to cancel atmospheric fluctuations. The antenna is able to drive both axes at a maximum velocity of 3 deg s-2 with a maximum acceleration of 6 deg. s-2. The telescope is currently equipped with SIS receivers for 100, 150, 230, and 345 GHz and a continuum backend and an FX-type digital autocorrelator with an instantaneous bandwidth of 512 MHz and 1024 channel outputs.

  10. 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

  11. 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

  12. Interferometric observations of molecular clouds in the Andromeda galaxy (M31)

    NASA Astrophysics Data System (ADS)

    Muller, S.

    The study of the molecular component of the ISM in galaxies is crucial to our understanding of their structure and dynamics. Carbon monoxyde remains the best tracer of this cold molecular matter. A complete survey of the Andromeda galaxy in CO(1-0) at 115 GHz has now been completed with the IRAM 30m telescope. In addition, high--angular resolution, high--sensitivity interferometric observations of selected fields have been obtained with the Plateau de Bure Interferometer. The dynamical mass of molecular complexes can then be estimated with the virial theorem, and compared to the mass derived from the CO luminosity using the magic conversion factor X = NH2 / WCO.

  13. Error analysis and data reduction for interferometric surface measurements

    NASA Astrophysics Data System (ADS)

    Zhou, Ping

    High-precision optical systems are generally tested using interferometry, since it often is the only way to achieve the desired measurement precision and accuracy. Interferometers can generally measure a surface to an accuracy of one hundredth of a wave. In order to achieve an accuracy to the next order of magnitude, one thousandth of a wave, each error source in the measurement must be characterized and calibrated. Errors in interferometric measurements are classified into random errors and systematic errors. An approach to estimate random errors in the measurement is provided, based on the variation in the data. Systematic errors, such as retrace error, imaging distortion, and error due to diffraction effects, are also studied in this dissertation. Methods to estimate the first order geometric error and errors due to diffraction effects are presented. Interferometer phase modulation transfer function (MTF) is another intrinsic error. The phase MTF of an infrared interferometer is measured with a phase Siemens star, and a Wiener filter is designed to recover the middle spatial frequency information. Map registration is required when there are two maps tested in different systems and one of these two maps needs to be subtracted from the other. Incorrect mapping causes wavefront errors. A smoothing filter method is presented which can reduce the sensitivity to registration error and improve the overall measurement accuracy. Interferometric optical testing with computer-generated holograms (CGH) is widely used for measuring aspheric surfaces. The accuracy of the drawn pattern on a hologram decides the accuracy of the measurement. Uncertainties in the CGH manufacturing process introduce errors in holograms and then the generated wavefront. An optimal design of the CGH is provided which can reduce the sensitivity to fabrication errors and give good diffraction efficiency for both chrome-on-glass and phase etched CGHs.

  14. 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.

  15. Partially coherent analysis of imaging and interferometric phased arrays: noise, correlations, and fluctuations.

    PubMed

    Withington, Stafford; Saklatvala, George; Hobson, Michael P

    2006-06-01

    Phased arrays are of considerable importance for far-infrared, submillimeter-wave, and microwave astronomy; they are also being developed for areas as diverse as optical switching, radar, and radio communications. We present a discretized, modal theory of imaging and interferometric phased arrays. It is shown that the average powers, field correlations, power fluctuations, and correlations between power fluctuations at the output ports of an imaging, or interferometric, phased array can be determined for a source in any state of spatial coherence and polarization, once the synthesized beam patterns are known. It is not necessary to know anything about the internal construction of the beam-forming networks; indeed, the beam patterns can be taken from experimental data. The synthesized beams can be nonorthogonal and even linearly dependent. Our theory leads to many conceptual insights and opens the way to a range of new design and simulation techniques. PMID:16715152

  16. Practical considerations for pointing a binocular telescope

    NASA Astrophysics Data System (ADS)

    De La Peña, Michele D.; Terrett, David L.; Thompson, David; Biddick, Christopher J.

    2010-07-01

    The Large Binocular Telescope (LBT) consists of two 8.4-meter primary mirrors on a common mount. When the telescope is complete, to complement the two primaries there will be two 0.9-meter adaptive secondaries and two tertiary mirror flats that all work to support a variety of Gregorian focal stations, as well as prime focus. A fundamental goal of the telescope is to perform interferometric observations, and therefore, there is a critical need for the ability to co-point the individual telescopes to high precision. Further, a unique aspect of the LBT is the comparatively large range over which the optics can be adjusted which provides flexibility for the acquisition of targets. In the most general case, an observer could be performing an observation using different targets, within constraints, with different instruments on each of the two telescope sides, with different observing duty cycles. As a consequence of the binocular nature of the telescope and the number of possible observing combinations, there are unique requirements imposed on the Telescope Control System (TCS), and in particular, on the Pointing Control Subsystem (PCS). It is the responsibility of the PCS to arbitrate the pointing requests made on the two sides of the telescope by the observers, incorporate guide updates, and generate tracking trajectories for the mount and the rotators, in conjunction with providing tip/tilt demands on the subsystem controlling the optical elements, and ensure each target remains on the specified location (i.e., pointing origin) in the focal plane during an active observation. This paper describes the current design and implementation of the LBT PCS.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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. PMID:26977642

  2. 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).

  3. 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)

  4. Geodetic radio interferometric surveying - Applications and results

    NASA Astrophysics Data System (ADS)

    Carter, W. E.; Robertson, D. S.; Mackay, J. R.

    1985-05-01

    A National Geodetic Survey (NGS) review of candidate technologies in 1977 came to the conclusion that very long baseline interferometry (VLBI) using the MARK III system was suited for developing a modern polar motion and UT1 monitoring service. Project POLARIS (Polar-Motion Analysis by Radio Interferometric Surveying) was implemented jointly by the NGS, NASA, and the U.S. Naval Observatory (USNO). Three permanent geodetic VLBI observatories were developed in the U.S., while West Germany constructed a dedicated geodetic VLBI observatory in Wettzell, Bavaria. Agencies in the two countries jointly initiated project IRIS (International Radio Interferometric Surveying) in 1982 with the objective to exploit the improved capabilities of the combined POLARIS/Wettzell network. Attention is given to aspects of VLBI, polar motion and UT1 time series, baseline length measurements, source coordinates, nutation, frequency standard evaluation, and relativistic deflection.

  5. 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

  6. Polarization-sensitive interferometric synthetic aperture microscopy

    NASA Astrophysics Data System (ADS)

    South, Fredrick A.; Liu, Yuan-Zhi; Xu, Yang; Shemonski, Nathan D.; Carney, P. Scott; Boppart, Stephen A.

    2015-11-01

    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.

  7. Focused-laser interferometric position sensor

    SciTech Connect

    Friedman, Stephen J.; Barwick, Brett; Batelaan, Herman

    2005-12-15

    We describe a simple method to measure the position shifts of an object with a range of tens of micrometers using a focused-laser (FL) interferometric position sensor. In this article we examine the effects of mechanical vibration on FL and Michelson interferometers. We tested both interferometers using vibration amplitudes ranging from 0 to 20 {mu}m. Our FL interferometer has a resolution much better than the diffraction grating periodicities of 10 and 14 {mu}m used in our experiments. A FL interferometer provides improved mechanical stability at the expense of spatial resolution. Our experimental results show that Michelson interferometers cannot be used when the vibration amplitude is more than an optical wavelength. The main purpose of this article is to demonstrate that a focused-laser interferometric position sensor can be used to measure the position shifts of an object on a less sensitive, micrometer scale when the vibration amplitude is too large to use a Michelson interferometer.

  8. Neutrino telescopes

    SciTech Connect

    Costantini, H.

    2012-09-15

    Neutrino astrophysics offers a new possibility to observe our Universe: high-energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if not exclusive) information about the cosmos: this young discipline extends in fact the conventional astronomy beyond the usual electromagnetic probe. The weak interaction of neutrinos with matter allows them to escape from the core of astrophysical objects and in this sense they represent a complementary messenger with respect to photons. However, their detection on Earth due to the small interaction cross section requires a large target mass. The aim of this article is to review the scientific motivations of the high-energy neutrino astrophysics, the detection principles together with the description of a running apparatus, the experiment ANTARES, the performance of this detector with some results, and the presentation of other neutrino telescope projects.

  9. 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.

  10. Real-time interferometric synthetic aperture microscopy.

    PubMed

    Ralston, Tyler S; Marks, Daniel L; Carney, P Scott; Boppart, Stephen A

    2008-02-18

    An interferometric synthetic aperture microscopy (ISAM) system design with real-time 2D cross-sectional processing is described in detail. The system can acquire, process, and display the ISAM reconstructed images at frame rates of 2.25 frames per second for 512 X 1024 pixel images. This system provides quantitatively meaningful structural information from previously indistinguishable scattering intensities and provides proof of feasibility for future real-time ISAM systems. PMID:18542337

  11. 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

  12. Interferometric SAR coherence classification utility assessment

    SciTech Connect

    Yocky, D.A.

    1998-03-01

    The classification utility of a dual-antenna interferometric synthetic aperture radar (IFSAR) is explored by comparison of maximum likelihood classification results for synthetic aperture radar (SAR) intensity images and IPSAR intensity and coherence images. The addition of IFSAR coherence improves the overall classification accuracy for classes of trees, water, and fields. A threshold intensity-coherence classifier is also compared to the intensity-only classification results.

  13. Fizeau interferometric cophasing of segmented mirrors: experimental validation.

    PubMed

    Cheetham, Anthony; Cvetojevic, Nick; Norris, Barnaby; Sivaramakrishnan, Anand; Tuthill, Peter

    2014-06-01

    We present an optical testbed demonstration of the Fizeau Interferometric Cophasing of Segmented Mirrors (FICSM) algorithm. FICSM allows a segmented mirror to be phased with a science imaging detector and three filters (selected among the normal science complement). It requires no specialised, dedicated wavefront sensing hardware. Applying random piston and tip/tilt aberrations of more than 5 wavelengths to a small segmented mirror array produced an initial unphased point spread function with an estimated Strehl ratio of 9% that served as the starting point for our phasing algorithm. After using the FICSM algorithm to cophase the pupil, we estimated a Strehl ratio of 94% based on a comparison between our data and simulated encircled energy metrics. Our final image quality is limited by the accuracy of our segment actuation, which yields a root mean square (RMS) wavefront error of 25 nm. This is the first hardware demonstration of coarse and fine phasing an 18-segment pupil with the James Webb Space Telescope (JWST) geometry using a single algorithm. FICSM can be implemented on JWST using any of its scientic imaging cameras making it useful as a fall-back in the event that accepted phasing strategies encounter problems. We present an operational sequence that would co-phase such an 18-segment primary in 3 sequential iterations of the FICSM algorithm. Similar sequences can be readily devised for any segmented mirror. PMID:24921490

  14. 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.

  15. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2009-01-01

    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 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 for 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. I review the status and capabilities of the observatory and instruments in the context of the major scientific goals.

  16. 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.

  17. The Astronomical Telescope of New York: a new 12-meter astronomical telescope

    NASA Astrophysics Data System (ADS)

    Sebring, T.; Junquist, R.; Stutzki, C.; Sebring, P.; Baum, S.

    2012-09-01

    The Astronomical Corporation of New York has commissioned a study of a 12-meter class telescope to be developed by a group of NY universities. The telescope concept builds on the basic principles established by the Keck telescopes; segmented primary mirror, Ritchey Chretien Nasmyth instrument layout, and light weight structures. New, lightweight, and low cost approaches are proposed for the primary mirror architecture, dome structure and mechanisms, telescope mount approach, and adaptive optics. Work on the design is supported by several NY based corporations and universities. The design offers a substantially larger aperture than any existing Visible/IR wavelength telescope at historically low cost. The concept employs an adaptive secondary mirror and laser guide star adaptive optics. Two First Light instruments are proposed; A High resolution near infrared spectrograph and a near infrared Integral field spectrograph/imager.

  18. 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

  19. 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.

  20. Formation metrology and control for large separated optics space telescopes

    NASA Technical Reports Server (NTRS)

    Mettler, E.; Quadrelli, M.; Breckenridge, W.

    2002-01-01

    In this paper we present formation flying performance analysis initial results for a representative large space telescope composed of separated optical elements [Mett 02]. A virtual-structure construct (an equivalent rigid body) is created by unique metrology and control that combines both centralized and decentralized methods. The formation may be in orbit at GEO for super-resolution Earth observation, as in the case of Figure 1, or it may be in an Earth-trailing orbit for astrophysics, Figure 2. Extended applications are envisioned for exo-solar planet interferometric imaging by a formation of very large separated optics telescopes, Figure 3. Space telescopes, with such large apertures and f/10 to f/100 optics, are not feasible if connected by massive metering structures. Instead, the new virtual-structure paradigm of information and control connectivity between the formation elements provides the necessary spatial rigidity and alignment precision for the telescope.

  1. 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.

  2. Architecture of the FIRST telescope

    NASA Astrophysics Data System (ADS)

    Cohen, Eri J.; Connell, Steven J.; Dodson, Kelly J.; Abbott, Jamie L.; Abusafieh, Abdel A.; Backovsky, Z. F.; Dyer, Jack E.; Escobedo-Torres, Javier; Friedman, Zvi; Hull, Anthony B.; Small, Donald W.; Thorndyke, Phil; Whitmore, Shaun A.

    2000-07-01

    The Far Infrared and Submillimeter Telescope (FIRST), is an ESA cornerstone mission, that will be used for photometry, imaging and spectroscopy in the 80 to 670 micrometer range. NASA, through the Jet Propulsion Laboratory (JPL), will be contributing the telescope and its design to ESA. This paper will discuss the work being done by JPL and Composite Optics, Incorporated (COI), the developer of the primary mirror technology. Optical and mechanical constraints for the telescope have been defined by ESA and evolved from their trade studies. Design drivers are wave front error (10 micrometer rms with a goal of 6 micrometer rms), mass (260 kg), primary mirror diameter (3.5 m) and f number (f/0.5), and the operational temperature (less than 90 K). In response to these requirements a low mass, low coefficient of thermal expansion (CTE) telescope has been designed using carbon fiber reinforced polymer (CFRP). This paper will first present background on the JPL/COI CFRP mirror development efforts. After selection of the material, the next two steps, that are being done in parallel, are to demonstrate that a large CFRP mirror could meet the requirements and to detail the optical, thermal and mechanical design of the telescope.

  3. Improving terrain height estimates from RADARSAT interferometric measurements

    SciTech Connect

    Thompson, P.A.; Eichel, P.H.; Calloway, T.M.

    1998-03-01

    The authors describe two methods of combining two-pass RADAR-SAT interferometric phase maps with existing DTED (digital terrain elevation data) to produce improved terrain height estimates. The first is a least-squares estimation procedure that fits the unwrapped phase data to a phase map computed from the DTED. The second is a filtering technique that combines the interferometric height map with the DTED map based on spatial frequency content. Both methods preserve the high fidelity of the interferometric data.

  4. Global Astrophysical Telescope System - telescope No. 2

    NASA Astrophysics Data System (ADS)

    Kamiński, Krzysztof; Baranowski, Roman; Fagas, Monika; Borczyk, Wojciech; Dimitrov, Wojciech; Polińska, Magdalena

    2014-02-01

    We present the new, second spectroscopic telescope of Poznań Astronomical Observatory. The telescope allows automatic simultaneous spectroscopic and photometric observations and is scheduled to begin operation from Arizona in autumn 2013. Together with the telescope located in Borowiec, Poland, it will constitute a perfect instrument for nearly continuous spectroscopic observations of variable stars. With both instruments operational, the Global Astrophysical Telescope System will be established.

  5. 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.

  6. 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.

  7. Alignment and performance of the Infrared Multi-Object Spectrometer

    NASA Astrophysics Data System (ADS)

    Connelly, Joseph A.; Ohl, Raymond G.; Mentzell, J. E.; Madison, Timothy J.; Hylan, Jason E.; Mink, Ronald G.; Saha, Timo T.; Tveekrem, June L.; Sparr, Leroy M.; Chambers, Victor J.; Fitzgerald, Danette L.; Greenhouse, Matthew A.; MacKenty, John W.

    2003-10-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator class instrument for the Kitt Peak National Observatory 4 and 2.1 m telescopes. IRMOS is a near-IR (0.8 2.5 μm) spectrometer with low- to mid-resolving power (R = 300 3000). IRMOS produces simultaneous spectra of ~100 objects in its 2.8 ´ 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 nm, a blackbody source provides a line at 1550 nm, 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.

  8. 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.

  9. 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.

  10. 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.

  11. The James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Gardner, J. P.

    2009-12-01

    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 (6.5m) 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 operate within the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy between 5 and 29 microns. The scientific investigations described here define the measurement capabilities of the telescope, but they do not imply that those particular observations will be made. JWST is a facility-class mission, so most of the observing time will be allocated to investigators from the international astronomical community through competitively-selected proposals.

  12. 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.

  13. Materials for cryogenically cooled infrared telescopes

    NASA Astrophysics Data System (ADS)

    Patin, J. F.; Cecconi, J. L.

    1988-11-01

    Materials with satisfactory performance between 300 and 4 K are studied in order to implement ISO satellite cryogenic equipment. The definitions of the anticorrosion treatment that meet both on ground and in orbit life requirements are also studied. The families of materials considered include optical application materials and structural/mechanical application materials with emphasis on dimensional stability and microyield strength. The test programs are described.

  14. Commanding and Error Recovery of a Binocular Telescope

    NASA Astrophysics Data System (ADS)

    De La Peña, M. D.; Biddick, C.; Thompson, D.

    2014-05-01

    The Large Binocular Telescope (LBT) consists of two 8.4-meter primary mirrors on a common mount. Each primary is complemented by an adaptive secondary, as well as a tertiary mirror. Since the LBT was designed to perform interferometric measurements, there is a critical need for the ability to control the optics of the two sides of the telescope to high precision. A unique aspect of the LBT is the comparatively large range over which the optics can be adjusted: the optics provide the flexibility for the deliberate acquisition of different targets on each side of the telescope. Designing a Telescope Control System (TCS) which allows for the efficient commanding of both telescope sides viewing the same target (co-pointed), having both telescope sides viewing different targets, and retaining the ability to perform as a single-eyed telescope (monocular mode) is challenging. Error status, particularly in the binocular context, must provide very clear and specific information with respect to the problem in order to enable efficient recovery. This paper describes the high-level flow of the telescope commanding, the binocular observation rules and the recovery strategy for the observer. As the observatory and astronomers gain more experience working within the binocular context, it is anticipated that new strategies may be developed.

  15. The 4-meter lunar engineering telescope

    NASA Technical Reports Server (NTRS)

    Peacock, Keith; Giannini, Judith A.; Kilgus, Charles C.; Bely, Pierre Y.; May, B. Scott; Cooper, Shannon A.; Schlimm, Gerard H.; Sounder, Charles; Ormond, Karen; Cheek, Eric

    1991-01-01

    The 16-meter diffraction limited lunar telescope incorporates a primary mirror with 312 one-meter segments; 3 nanometer active optics surface control with laser metrology and hexapod positioners; a space frame structure with one-millimeter stability; and a hexapod mount for pointing. The design data needed to limit risk in this development can be obtained by building a smaller engineering telescope on the moon with all of the features of the 16-meter design. This paper presents a 4.33-meter engineering telescope concept developed by the Summer 1990 Student Program of the NASA/JHU Space Grant Consortium Lunar Telescope Project. The primary mirror, made up of 18 one-meter hexagonal segments, is sized to provide interesting science as well as engineering data. The optics are configured as a Ritchey-Chretien with a coude relay to the focal plane beneath the surface. The optical path is continuously monitored with 3-nanometer precision interferometrically. An active optics processor and piezoelectric actuators operate to maintain the end-to-end optical configuration established by wave front sensing using a guide star. The mirror segments, consisting of a one-centimeter thick faceplate on 30-cm deep ribs, maintain the surface figure to a few nanometers under lunar gravity and thermal environment.

  16. High resolution broad-band spectroscopy in the NIR using the Triplespec externally dispersed interferometer at the Hale telescope

    NASA Astrophysics Data System (ADS)

    Erskine, David J.; Edelstein, J.; Sirk, M.; Wishnow, E.; Ishikawa, Y.; McDonald, E.; Shourt, W. V.

    2014-07-01

    High resolution broad-band spectroscopy at near-infrared wavelengths has been performed using externally dis- persed interferometry (EDI) at the Hale telescope at Mt. Palomar. The EDI technique uses a field-widened Michelson interferometer in series with a dispersive spectrograph, and is able to recover a spectrum with a resolution 4 to 10 times higher than the existing grating spectrograph. This method increases the resolution well beyond the classical limits enforced by the slit width and the detector pixel Nyquist limit and, in principle, decreases the effect of pupil variation on the instrument line-shape function. The EDI technique permits arbi- trarily higher resolution measurements using the higher throughput, lower weight, size, and expense of a lower resolution spectrograph. Observations of many stars were performed with the TEDI interferometer mounted within the central hole of the 200 inch primary mirror. Light from the interferometer was then dispersed by the TripleSpec near-infrared echelle spectrograph. Continuous spectra between 950 and 2450 nm with a resolution as high as ~27,000 were recovered from data taken with TripleSpec at a native resolution of ˜2,700. Aspects of data analysis for interferometric spectral reconstruction are described. This technique has applications in im- proving measurements of high-resolution stellar template spectra, critical for precision Doppler velocimetry using conventional spectroscopic methods. A new interferometer to be applied for this purpose at visible wavelengths is under construction.

  17. 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.

  18. Interferometric tomography metrology of conformal optics

    NASA Astrophysics Data System (ADS)

    Gutin, Mikhail; Gutin, Olga; Wang, Xu-Ming; Ehlinger, Dennis

    2013-06-01

    Conformal windows and domes improve aerodynamic quality of missiles and aircraft but introduce significant optical aberrations. These aberrations can be compensated, provided both window and corrective optics are fabricated to high tolerances. Highly accurate measurement of conformal optics is required for success of the fabrication process. This paper describes the development of the Interferometric Tomography - a new tool for metrology of conformal aspheric optics, including optics with very high aberrations. The metrology system is designed to measure wavefront aberrations as well as the optical figure of both surfaces.

  19. 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.

  20. Constraining Mass Ratio and Extinction in the FU Orionis Binary System with Infrared Integral Field Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pueyo, Laurent; Hillenbrand, Lynne; Vasisht, Gautam; Oppenheimer, Ben R.; Monnier, John D.; Hinkley, Sasha; Crepp, Justin; Roberts, Lewis C., Jr.; Brenner, Douglas; Zimmerman, Neil; Parry, Ian; Beichman, Charles; Dekany, Richard; Shao, Mike; Burruss, Rick; Cady, Eric; Roberts, Jenny; Soummer, Rémi

    2012-09-01

    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 0farcs5 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 μm 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, AV = 8-12, with an effective temperature of ~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.