WorldWideScience

Sample records for astronomical spectrograph calibration

  1. Using commercial amateur astronomical spectrographs

    CERN Document Server

    Hopkins, Jeffrey L

    2014-01-01

    Amateur astronomers interested in learning more about astronomical spectroscopy now have the guide they need. It provides detailed information about how to get started inexpensively with low-resolution spectroscopy, and then how to move on to more advanced  high-resolution spectroscopy. Uniquely, the instructions concentrate very much on the practical aspects of using commercially-available spectroscopes, rather than simply explaining how spectroscopes work. The book includes a clear explanation of the laboratory theory behind astronomical spectrographs, and goes on to extensively cover the practical application of astronomical spectroscopy in detail. Four popular and reasonably-priced commercially available diffraction grating spectrographs are used as examples. The first is a low-resolution transmission diffraction grating, the Star Analyser spectrograph. The second is an inexpensive fiber optic coupled bench spectrograph that can be used to learn more about spectroscopy. The third is a newcomer, the ALPY ...

  2. Astronomical calibration of the Maastrichtian (Late Cretaceous)

    DEFF Research Database (Denmark)

    Husson, Dorothée; Galbrun, Bruno; Laskar, Jacques;

    2011-01-01

    Recent improvements to astronomical modeling of the Solar System have contributed to important refinements of the Cenozoic time scale through astronomical calibration of sedimentary series. We extend this astronomical calibration into the Cretaceous, on the base of the 405 ka orbital eccentricity...

  3. A spectrograph for exoplanet observations calibrated at the centimetre-per-second level.

    Science.gov (United States)

    Wilken, Tobias; Curto, Gaspare Lo; Probst, Rafael A; Steinmetz, Tilo; Manescau, Antonio; Pasquini, Luca; González Hernández, Jonay I; Rebolo, Rafael; Hänsch, Theodor W; Udem, Thomas; Holzwarth, Ronald

    2012-05-31

    The best spectrographs are limited in stability by their calibration light source. Laser frequency combs are the ideal calibrators for astronomical spectrographs. They emit a spectrum of lines that are equally spaced in frequency and that are as accurate and stable as the atomic clock relative to which the comb is stabilized. Absolute calibration provides the radial velocity of an astronomical object relative to the observer (on Earth). For the detection of Earth-mass exoplanets in Earth-like orbits around solar-type stars, or of cosmic acceleration, the observable is a tiny velocity change of less than 10 cm s(-1), where the repeatability of the calibration--the variation in stability across observations--is important. Hitherto, only laboratory systems or spectrograph calibrations of limited performance have been demonstrated. Here we report the calibration of an astronomical spectrograph with a short-term Doppler shift repeatability of 2.5 cm s(-1), and use it to monitor the star HD 75289 and recompute the orbit of its planet. This repeatability should make it possible to detect Earth-like planets in the habitable zone of star or even to measure the cosmic acceleration directly.

  4. Performance of a laser frequency comb calibration system with a high-resolution solar echelle spectrograph

    Science.gov (United States)

    Doerr, H.-P.; Kentischer, T. J.; Steinmetz, T.; Probst, R. A.; Franz, M.; Holzwarth, R.; Udem, Th.; Hänsch, T. W.; Schmidt, W.

    2012-09-01

    Laser frequency combs (LFC) provide a direct link between the radio frequency (RF) and the optical frequency regime. The comb-like spectrum of an LFC is formed by exact equidistant laser modes, whose absolute optical frequencies are controlled by RF-references such as atomic clocks or GPS receivers. While nowadays LFCs are routinely used in metrological and spectroscopic fields, their application in astronomy was delayed until recently when systems became available with a mode spacing and wavelength coverage suitable for calibration of astronomical spectrographs. We developed a LFC based calibration system for the high-resolution echelle spectrograph at the German Vacuum Tower Telescope (VTT), located at the Teide observatory, Tenerife, Canary Islands. To characterize the calibration performance of the instrument, we use an all-fiber setup where sunlight and calibration light are fed to the spectrograph by the same single-mode fiber, eliminating systematic effects related to variable grating illumination.

  5. Astronomical optical frequency comb generation and test in a fiber-fed MUSE spectrograph

    Science.gov (United States)

    Chavez Boggio, J. M.; Fremberg, T.; Moralejo, B.; Rutowska, M.; Hernandez, E.; Zajnulina, M.; Kelz, A.; Bodenmüller, D.; Sandin, C.; Wysmolek, M.; Sayinc, H.; Neumann, J.; Haynes, R.; Roth, M. M.

    2014-07-01

    We here report on recent progress on astronomical optical frequency comb generation at innoFSPEC-Potsdam and present preliminary test results using the fiber-fed Multi Unit Spectroscopic Explorer (MUSE) spectrograph. The frequency comb is generated by propagating two free-running lasers at 1554.3 and 1558.9 nm through two dispersionoptimized nonlinear fibers. The generated comb is centered at 1590 nm and comprises more than one hundred lines with an optical-signal-to-noise ratio larger than 30 dB. A nonlinear crystal is used to frequency double the whole comb spectrum, which is efficiently converted into the 800 nm spectral band. We evaluate first the wavelength stability using an optical spectrum analyzer with 0.02 nm resolution and wavelength grid of 0.01 nm. After confirming the stability within 0.01 nm, we compare the spectra of the astro-comb and the Ne and Hg calibration lamps: the astro-comb exhibits a much larger number of lines than lamp calibration sources. A series of preliminary tests using a fiber-fed MUSE spectrograph are subsequently carried out with the main goal of assessing the equidistancy of the comb lines. Using a P3d data reduction software we determine the centroid and the width of each comb line (for each of the 400 fibers feeding the spectrograph): equidistancy is confirmed with an absolute accuracy of 0.4 pm.

  6. Calibrating echelle spectrographs with Fabry-Perot etalons

    CERN Document Server

    Bauer, Florian F; Reiners, Ansgar

    2015-01-01

    Over the past decades hollow-cathode lamps have been calibration standards for spectroscopic measurements. Advancing to cm/s radial velocity precisions with the next generation of instruments requires more suitable calibration sources with more lines and less dynamic range problems. Fabry-Perot interferometers provide a regular and dense grid of lines and homogeneous amplitudes making them good candidates for next generation calibrators. We investigate the usefulness of Fabry-Perot etalons in wavelength calibration, present an algorithm to incorporate the etalon spectrum in the wavelength solution and examine potential problems. The quasi periodic pattern of Fabry-Perot lines is used along with a hollow-cathode lamp to anchor the numerous spectral features on an absolute scale. We test our method with the HARPS spectrograph and compare our wavelength solution to the one derived from a laser frequency comb. The combined hollow-cathode lamp/etalon calibration overcomes large distortion (50 m/s) in the wavelengt...

  7. Calibrating echelle spectrographs with Fabry-Pérot etalons

    Science.gov (United States)

    Bauer, F. F.; Zechmeister, M.; Reiners, A.

    2015-09-01

    Context. Over the past decades hollow-cathode lamps have been calibration standards for spectroscopic measurements. Advancing to cm/s radial velocity precisions with the next generation of instruments requires more suitable calibration sources with more lines and fewer dynamic range problems. Fabry-Pérot interferometers provide a regular and dense grid of lines and homogeneous amplitudes, which makes them good candidates for next-generation calibrators. Aims: We investigate the usefulness of Fabry-Pérot etalons in wavelength calibration, present an algorithm to incorporate the etalon spectrum in the wavelength solution, and examine potential problems. Methods: The quasi-periodic pattern of Fabry-Pérot lines was used along with a hollow-cathode lamp to anchor the numerous spectral features on an absolute scale. We tested our method with the HARPS spectrograph and compared our wavelength solution to the one derived from a laser frequency comb. Results: The combined hollow-cathode lamp/etalon calibration overcomes large distortion (50 m/s) in the wavelength solution of the HARPS data reduction software. The direct comparison to the laser frequency comb shows differences of only 10 m/s at most. Conclusions: Combining hollow-cathode lamps with Fabry-Pérot interferometers can lead to substantial improvements in the wavelength calibration of echelle spectrographs. Etalons can provide economical alternatives to the laser frequency comb, especially for smaller projects.

  8. Modelling high resolution Echelle spectrographs for calibrations: Hanle Echelle spectrograph, a case study

    CERN Document Server

    Chanumolu, Anantha; Thirupathi, Sivarani

    2015-01-01

    We present a modelling scheme that predicts the centroids of spectral line features for a high resolution Echelle spectrograph to a high accuracy. Towards this, a computing scheme is used, whereby any astronomical spectrograph can be modelled and controlled without recourse to a ray tracing program. The computations are based on paraxial ray trace and exact corrections added for certain surface types and Buchdahl aberration coefficients for complex modules. The resultant chain of paraxial ray traces and corrections for all relevant components is used to calculate the location of any spectral line on the detector under all normal operating conditions with a high degree of certainty. This will allow a semi-autonomous control using simple in-house, programming modules. The scheme is simple enough to be implemented even in a spreadsheet or in any scripting language. Such a model along with an optimization routine can represent the real time behaviour of the instrument. We present here a case study for Hanle Echel...

  9. Precision spectroscopy with a frequency-comb-calibrated solar spectrograph

    Science.gov (United States)

    Doerr, H.-P.

    2015-06-01

    The measurement of the velocity field of the plasma at the solar surface is a standard diagnostic tool in observational solar physics. Detailed information about the energy transport as well as on the stratification of temperature, pressure and magnetic fields in the solar atmosphere are encoded in Doppler shifts and in the precise shape of the spectral lines. The available instruments deliver data of excellent quality and precision. However, absolute wavelength calibration in solar spectroscopy was so far mostly limited to indirect methods and in general suffers from large systematic uncertainties of the order of 100 m/s. During the course of this thesis, a novel wavelength calibration system based on a laser frequency comb was deployed to the solar Vacuum Tower Telescope (VTT), Tenerife, with the goal of enabling highly accurate solar wavelength measurements at the level of 1 m/s on an absolute scale. The frequency comb was developed in a collaboration between the Kiepenheuer-Institute for Solar Physics, Freiburg, Germany and the Max Planck Institute for Quantum Optics, Garching, Germany. The efforts cumulated in the new prototype instrument LARS (Lars is an Absolute Reference Spectrograph) for solar precision spectroscopy which is in preliminary scientific operation since~2013. The instrument is based on the high-resolution echelle spectrograph of the VTT for which feed optics based on single-mode optical fibres were developed for this project. The setup routinely achieves an absolute calibration accuracy of 60 cm/s and a repeatability of 2.5 cm/s. An unprecedented repeatability of only 0.32 cm/s could be demonstrated with a differential calibration scheme. In combination with the high spectral resolving power of the spectrograph of 7x10^5 and virtually absent internal scattered light, LARS provides a spectral purity and fidelity that previously was the domain of Fourier-transform spectrometers only. The instrument therefore provides unique capabilities for

  10. Absolute calibration of space-resolving soft X-ray spectrograph for plasma diagnostics

    Science.gov (United States)

    Yoshikawa, M.; Okamoto, Y.; Kawamori, E.; Watanabe, Y.; Watabe, C.; Yamaguchi, N.; Tamano, T.

    2001-07-01

    A grazing incidence flat-field soft X-ray (20-350 Å) spectrograph was constructed and applied for impurity diagnostics in the GAMMA 10 fusion plasma. The spectrograph consisted of a limited height entrance slit, an aberration-corrected concave grating, a microchannel-plate intensified detector and an instant camera/a high speed solid state camera. An absolute calibration experiment for the SX spectrograph was performed at the Photon Factory in the High Energy Accelerator Research Organization with monitoring the incident synchrotron beam intensity by using an absolutely calibrated XUV silicon photodiode. From the results of absolute calibration of the spectrograph, the radiation loss from the plasma was obtained.

  11. Absolute calibration of space-resolving soft X-ray spectrograph for plasma diagnostics

    CERN Document Server

    Yoshikawa, M; Kawamori, E; Watanabe, Y; Watabe, C; Yamaguchi, N; Tamano, T

    2001-01-01

    A grazing incidence flat-field soft X-ray (20-350 A) spectrograph was constructed and applied for impurity diagnostics in the GAMMA 10 fusion plasma. The spectrograph consisted of a limited height entrance slit, an aberration-corrected concave grating, a microchannel-plate intensified detector and an instant camera/a high speed solid state camera. An absolute calibration experiment for the SX spectrograph was performed at the Photon Factory in the High Energy Accelerator Research Organization with monitoring the incident synchrotron beam intensity by using an absolutely calibrated XUV silicon photodiode. From the results of absolute calibration of the spectrograph, the radiation loss from the plasma was obtained.

  12. The assembly, calibration, and preliminary results from the Colorado high-resolution Echelle stellar spectrograph (CHESS)

    Science.gov (United States)

    Hoadley, Keri; France, Kevin; Nell, Nicholas; Kane, Robert; Schultz, Ted; Beasley, Matthew; Green, James; Kulow, Jen; Kersgaard, Eliot; Fleming, Brian

    2014-07-01

    The Colorado High-resolution Echelle Stellar Spectrograph (CHESS) is a far ultraviolet (FUV) rocket-borne experiment designed to study the atomic-to-molecular transitions within translucent interstellar clouds. CHESS is an objective echelle spectrograph operating at f/12.4 and resolving power of 120,000 over a band pass of 100 - 160 nm. The echelle flight grating is the product of a research and development project with LightSmyth Inc. and was coated at Goddard Space Flight Center (GSFC) with Al+LiF. It has an empirically-determined groove density of 71.67 grooves/mm. At the Center for Astrophysics and Space Astronomy (CASA) at the University of Colorado (CU), we measured the efficiencies of the peak and adjacent dispersion orders throughout the 90 - 165 nm band pass to characterize the behavior of the grating for pre-flight calibrations and to assess the scattered-light behavior. The crossdispersing grating, developed and ruled by Horiba Jobin-Yvon, is a holographically-ruled, low line density (351 grooves/mm), powered optic with a toroidal surface curvature. The CHESS cross-disperser was also coated at GSFC; Cr+Al+LiF was deposited to enhance far-UV efficiency. Results from final efficiency and reflectivity measurements of both optics are presented. We utilize a cross-strip anode microchannel plate (MCP) detector built by Sensor Sciences to achieve high resolution (25 μm spatial resolution) and data collection rates (~ 106 photons/second) over a large format (40mm round, digitized to 8k x 8k) for the first time in an astronomical sounding rocket flight. The CHESS instrument was successfully launched from White Sands Missile Range on 24 May 2014. We present pre-flight sensitivity, effective area calculations, lab spectra and calibration results, and touch on first results and post-flight calibration plans.

  13. Design and modeling of a moderate-resolution astronomic spectrograph with volume-phase holographic gratings

    CERN Document Server

    Muslimov, Eduard R; Fabrika, Sergey N; Pavlycheva, Nadezhda K

    2016-01-01

    We present an optical design of astronomic spectrograph based on a cascade of volume-phase holographic gratings. The cascade consists of three gratings. Each of them provides moderately high spectral resolution in a narrow range of 83 nm. Thus the spectrum image represents three lines covering region 430-680 nm. Two versions of the scheme are described: a full-scale one with estimated resolving power of 5300-7900 and a small-sized one intended for creation of a lab prototype, which provides the resolving power of 1500-3000. Diffraction efficiency modeling confirms that the system throughput can reach 75 %, while stray light caused by the gratings crosstalk is negligible. We also propose a design of image slicer and focal reducer allowing to couple the instrument with the 6-m telescope. Finally, we present concept of the opto-mechanical design.

  14. Astrometry.net: Blind Astrometric Calibration of Arbitrary Astronomical Images

    Science.gov (United States)

    Lang, Dustin; Hogg, David W.; Mierle, Keir; Blanton, Michael; Roweis, Sam

    2010-05-01

    We have built a reliable and robust system that takes as input an astronomical image, and returns as output the pointing, scale, and orientation of that image (the astrometric calibration or World Coordinate System information). The system requires no first guess, and works with the information in the image pixels alone; that is, the problem is a generalization of the "lost in space" problem in which nothing—not even the image scale—is known. After robust source detection is performed in the input image, asterisms (sets of four or five stars) are geometrically hashed and compared to pre-indexed hashes to generate hypotheses about the astrometric calibration. A hypothesis is only accepted as true if it passes a Bayesian decision theory test against a null hypothesis. With indices built from the USNO-B catalog and designed for uniformity of coverage and redundancy, the success rate is >99.9% for contemporary near-ultraviolet and visual imaging survey data, with no false positives. The failure rate is consistent with the incompleteness of the USNO-B catalog; augmentation with indices built from the Two Micron All Sky Survey catalog brings the completeness to 100% with no false positives. We are using this system to generate consistent and standards-compliant meta-data for digital and digitized imaging from plate repositories, automated observatories, individual scientific investigators, and hobbyists. This is the first step in a program of making it possible to trust calibration meta-data for astronomical data of arbitrary provenance.

  15. Precession of the Equinoxes and the Calibration of Astronomical Epochs

    CERN Document Server

    Sidharth, Burra G

    2010-01-01

    Astronomical observations were used as a marker for time and the Calendar from ancient times. A more subtle calibration of epochs is thrown up by an observation of the position of the solstices and equinoxes, because these points shift in the sky with the years resulting in the gradual shift of celestial longitudes $\\lambda$. Chronology based on such observations however needs to be backed up by hard evidence. We match both to take us back to $10,000$ B.C., the epi-paleolithic period, and the beginning of civilization itself.

  16. A flux calibration device for the SuperNova Integral Field Spectrograph (SNIFS)

    CERN Document Server

    Lombardo, Simona; Hoffmann, Akos; Kowalski, Marek; Kuesters, Daniel; Reif, Klaus; Rigault, Mickael

    2014-01-01

    Observational cosmology employing optical surveys often require precise flux calibration. In this context we present SNIFS Calibration Apparatus (SCALA), a flux calibration system developed for the SuperNova Integral Field Spectrograph (SNIFS), operating at the University of Hawaii 2.2 m telescope. SCALA consists of a hexagonal array of 18 small parabolic mirrors distributed over the face of, and feeding parallel light to, the telescope entrance pupil. The mirrors are illuminated by integrating spheres and a wavelength-tunable (from UV to IR) light source, generating light beams with opening angles of 1 degree. These nearly parallel beams are flat and flux-calibrated at a subpercent level, enabling us to calibrate our "telescope + SNIFS system" at the required precision.

  17. A Laser Frequency Comb System for Absolute Calibration of the VTT Echelle Spectrograph

    CERN Document Server

    Doerr, H -P; Holzwarth, R; Schmidt, T Kentischer und W

    2012-01-01

    A wavelength calibration system based on a laser frequency comb (LFC) was developed in a co-operation between the Kiepenheuer-Institut f\\"ur Sonnenphysik, Freiburg, Germany and the Max-Planck-Institut f\\"ur Quantenoptik, Garching, Germany for permanent installation at the German Vacuum Tower Telescope (VTT) on Tenerife, Canary Islands. The system was installed successfully in October 2011. By simultaneously recording the spectra from the Sun and the LFC, for each exposure a calibration curve can be derived from the known frequencies of the comb modes that is suitable for absolute calibration at the meters per second level. We briefly summarize some topics in solar physics that benefit from absolute spectroscopy and point out the advantages of LFC compared to traditional calibration techniques. We also sketch the basic setup of the VTT calibration system and its integration with the existing echelle spectrograph.

  18. A Laser Frequency Comb System for Absolute Calibration of the VTT Echelle Spectrograph

    Science.gov (United States)

    Doerr, H.-P.; Steinmetz, T.; Holzwarth, R.; Kentischer, T.; Schmidt, W.

    2012-10-01

    A wavelength calibration system based on a laser frequency comb (LFC) was developed in a co-operation between the Kiepenheuer-Institut für Sonnenphysik, Freiburg, Germany and the Max-Planck-Institut für Quantenoptik, Garching, Germany for permanent installation at the German Vacuum Tower Telescope (VTT) on Tenerife, Canary Islands. The system was installed successfully in October 2011. By simultaneously recording the spectra from the Sun and the LFC, for each exposure a calibration curve can be derived from the known frequencies of the comb modes that is suitable for absolute calibration at the meters per second level. We briefly summarize some topics in solar physics that benefit from absolute spectroscopy and point out the advantages of LFC compared to traditional calibration techniques. We also sketch the basic setup of the VTT calibration system and its integration with the existing echelle spectrograph.

  19. A flux calibration device for the SuperNova Integral Field Spectrograph (SNIFS)

    Science.gov (United States)

    Lombardo, Simona; Aldering, Greg; Hoffmann, Akos; Kowalski, Marek; Kuesters, Daniel; Reif, Klaus; Rigault, Michael

    2014-07-01

    Observational cosmology employing optical surveys often require precise flux calibration. In this context we present SNIFS Calibration Apparatus (SCALA), a flux calibration system developed for the SuperNova Integral Field Spectrograph (SNIFS), operating at the University of Hawaii 2.2 m telescope. SCALA consists of a hexagonal array of 18 small parabolic mirrors distributed over the face of, and feeding parallel light to, the telescope entrance pupil. The mirrors are illuminated by integrating spheres and a wavelength-tunable (from UV to IR) light source, generating light beams with opening angles of 1°. These nearly parallel beams are flat and flux-calibrated at a subpercent level, enabling us to calibrate our "telescope + SNIFS system" at the required precision.

  20. Astrometry.net: Blind astrometric calibration of arbitrary astronomical images

    CERN Document Server

    Lang, Dustin; Mierle, Keir; Blanton, Michael; Roweis, Sam

    2009-01-01

    We have built a reliable and robust system that takes as input an astronomical image, and returns as output the pointing, scale, and orientation of that image (the astrometric calibration or WCS information). The system requires no first guess, and works with the information in the image pixels alone; that is, the problem is a generalization of the "lost in space" problem in which nothing--not even the image scale--is known. After robust source detection is performed in the input image, asterisms (sets of four or five stars) are geometrically hashed and compared to pre-indexed hashes to generate hypotheses about the astrometric calibration. A hypothesis is only accepted as true if it passes a Bayesian decision theory test against a background hypothesis. With indices built from the USNO-B Catalog and designed for uniformity of coverage and redundancy, the success rate is 99.9% for contemporary near-ultraviolet and visual imaging survey data, with no false positives. The failure rate is consistent with the inc...

  1. The list of tantalum lines for wavelengths calibration of the Hamilton echelle-spectrograph

    CERN Document Server

    Pakhomov, Yu V

    2015-01-01

    We present solution of the problem of wavelength calibration for Hamilton Echelle spectrograph using hollow cathode lamp, which was operated at Lick Observatory Shane telescope before June 9, 2011. The spectrum of the lamp claimed to be thorium-argon, contains, in addition to the lines of thorium and argon, a number of the unrecognized lines identified by us with tantalum. Using atomic data for measured lines of tantalum and thorium, we estimated the temperature of the gas in the lamp as T=3120+/-60 K. From the atomic line database VALD3 we selected all lines of TaI and TaII which can be seen in the spectrum of the lamp and compiled a list for the use in the processing of spectral observations. We note a limitation of the accuracy of calibration due to the influence of the hyperfine line splitting.

  2. Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

    Science.gov (United States)

    Hock, R. A.; Chamberlin, P. C.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Woods, E. C.

    2012-01-01

    The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. ( Solar Phys., 2010, doi:10.1007/s11207-009-9485-8). In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

  3. Radio Astronomical Polarimetry and Point-Source Calibration

    Science.gov (United States)

    van Straten, W.

    2004-05-01

    A mathematical framework is presented for use in the experimental determination of the polarimetric response of observatory instrumentation. Elementary principles of linear algebra are applied to model the full matrix description of the polarization measurement equation by least-squares estimation of nonlinear, scalar parameters. The formalism is applied to calibrate the center element of the Parkes Multibeam receiver using observations of the millisecond pulsar PSR J0437-4715 and the radio galaxy 3C 218 (Hydra A).

  4. Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra

    CERN Document Server

    Becker, Juliette C; Vanderburg, Andrew; Morton, Timothy D

    2015-01-01

    We present a technique to extract radial velocity measurements from echelle spectrograph observations of rapidly rotating stars ($V\\sin{i} \\gtrsim 50$ km s$^{-1}$). This type of measurement is difficult because the line widths of such stars are often comparable to the width of a single echelle order. To compensate for the scarcity of lines and Doppler information content, we have developed a process that forward-models the observations, fitting the radial velocity shift of the star for all echelle orders simultaneously with the echelle blaze function. We use our technique to extract radial velocity measurements from a sample of rapidly rotating A- and B-type stars used as calibrator stars observed by the California Planet Survey observations. We measure absolute radial velocities with a precision ranging from 0.5-2.0 km s$^{-1}$ per epoch for more than 100 A- and B-type stars. In our sample of 10 well-sampled stars with radial velocity scatter in excess of their measurement uncertainties, three of these are s...

  5. A novel ion source for the calibration of an MRTOF Mass Spectrograph to be used in superheavy elements mass measurements

    CERN Document Server

    Naimi, S; Ito, Y; Mita, H; Okada, K; Ozawa, A; Schury, P; Sonoda, T; Takamine, A; Wada, M; Wollnik, H

    2012-01-01

    A novel ion source based on electrospray ionization and radiofrequency carpet technique has been built. This ion source is designed to deliver relatively heavy molecules for the calibration of a multi reflection time-of-flight mass spectrograph (MRTOF-MS) that will be used for direct mass measurements of superheavy elements. The operation of the ion source as well as the analysis by the MRTOF-MS with heavy molecular ions is described.

  6. Million object spectrograph

    Science.gov (United States)

    Ditto, Thomas D.; Ritter, Joseph M.

    2008-07-01

    A new class of astronomical telescope with a primary objective grating (POG) has been studied as an alternative to mirrors. Nineteenth century POG telescopes suffered from low resolution and ambiguity of overlapping spectra as well as background noise. The present design uses a conventional secondary spectrograph to disambiguate all objects while enjoying a very wide instantaneous field-of-view, up to 40°. The POG competes with mirrors, in part, because diffraction gratings provide the very chromatic dispersion that mirrors defeat. The resulting telescope deals effectively with long-standing restrictions on multiple object spectrographs (MOS). The combination of a POG operating in the first-order, coupled to a spectrographic astronomical telescope, isolates spectra from all objects in the free spectral range of the primary. First disclosed as a concept in year 2002, a physical proof-of-principle is now reported. The miniature laboratory model used a 50 mm plane grating primary and was able to disambiguate between objects appearing at angular resolutions of 55 arcseconds and spectral spacings of 0.15 nm. Astronomical performance is a matter of increasing instrument size. A POG configured according to our specifications has no moving parts during observations and is extensible to any length that can be held flat to tolerances approaching float glass. The resulting telescope could record over one million spectra per night of objects in a line of right ascension. The novel MOS does not require pre-imaging to start acquisition of uncharted star fields. Problems are anticipated in calibration and integration time. We propose means to ameliorate them.

  7. Development of Fiber Fabry-Perot Interferometers as Stable Near-infrared Calibration Sources for High Resolution Spectrographs

    CERN Document Server

    Halverson, Samuel; Ramsey, Lawrence; Hearty, Fred; Wilson, John; Holtzman, Jon; Redman, Stephen; Nave, Gillian; Nidever, David; Nelson, Matt; Venditti, Nick; Bizyaev, Dmitry; Fleming, Scott

    2014-01-01

    We discuss the ongoing development of single-mode fiber Fabry-Perot (FFP) Interferometers as precise astro-photonic calibration sources for high precision radial velocity (RV) spectrographs. FFPs are simple, inexpensive, monolithic units that can yield a stable and repeatable output spectrum. An FFP is a unique alternative to a traditional etalon, as the interferometric cavity is made of single-mode fiber rather than an air-gap spacer. This design allows for excellent collimation, high spectral finesse, rigid mechanical stability, insensitivity to vibrations, and no need for vacuum operation. The device we have tested is a commercially available product from Micron Optics. Our development path is targeted towards a calibration source for the Habitable-Zone Planet Finder (HPF), a near-infrared spectrograph designed to detect terrestrial-mass planets around low-mass stars, but this reference could also be used in many existing and planned fiber-fed spectrographs as we illustrate using the Apache Point Observato...

  8. Precise astronomical flux calibration and its impact on studying the nature of the dark energy

    Science.gov (United States)

    Stubbs, Christopher W.; Brown, Yorke J.

    2015-12-01

    Measurements of the luminosity of Type Ia supernovae versus redshift provided the original evidence for the accelerating expansion of the Universe and the existence of dark energy. Despite substantial improvements in survey methodology, systematic uncertainty in flux calibration dominates the error budget for this technique, exceeding both statistics and other systematic uncertainties. Consequently, any further collection of Type Ia supernova data will fail to refine the constraints on the nature of dark energy unless we also improve the state of the art in astronomical flux calibration to the order of 1%. We describe how these systematic errors arise from calibration of instrumental sensitivity, atmospheric transmission and Galactic extinction, and discuss ongoing efforts to meet the 1% precision challenge using white dwarf stars as celestial standards, exquisitely calibrated detectors as fundamental metrologic standards, and real-time atmospheric monitoring.

  9. Precise Astronomical Flux Calibration and its Impact on Studying the Nature of Dark Energy

    CERN Document Server

    Stubbs, Christopher W

    2016-01-01

    Measurements of the luminosity of type Ia supernovae vs. redshift provided the original evidence for the accelerating expansion of the Universe and the existence of dark energy. Despite substantial improvements in survey methodology, systematic uncertainty in flux calibration dominates the error budget for this technique, exceeding both statistics and other systematic uncertainties. Consequently, any further collection of type Ia supernova data will fail to refine the constraints on the nature of dark energy unless we also improve the state of the art in astronomical flux calibration to the order of 1%. We describe how these systematic errors arise from calibration of instrumental sensitivity, atmospheric transmission, and Galactic extinction, and discuss ongoing efforts to meet the 1% precision challenge using white dwarf stars as celestial standards, exquisitely calibrated detectors as fundamental metrologic standards, and real-time atmospheric monitoring.

  10. A Laser Frequency Comb System for Absolute Calibration of the VTT Echelle Spectrograph

    OpenAIRE

    Doerr, H. -P.; T Steinmetz; Holzwarth, R.; Schmidt, T. Kentischer und W.

    2012-01-01

    A wavelength calibration system based on a laser frequency comb (LFC) was developed in a co-operation between the Kiepenheuer-Institut f\\"ur Sonnenphysik, Freiburg, Germany and the Max-Planck-Institut f\\"ur Quantenoptik, Garching, Germany for permanent installation at the German Vacuum Tower Telescope (VTT) on Tenerife, Canary Islands. The system was installed successfully in October 2011. By simultaneously recording the spectra from the Sun and the LFC, for each exposure a calibration curve ...

  11. Astronomical optics

    CERN Document Server

    Schroeder, Daniel J

    1988-01-01

    Written by a recognized expert in the field, this clearly presented, well-illustrated book provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic instruments used by astronomers of today.Key Features* Written by a recognized expert in the field* Provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic i

  12. Astronomical calibration and global correlation of the Santonian (Cretaceous) based on the marine carbon isotope record

    Science.gov (United States)

    Thibault, N.; Jarvis, I.; Voigt, S.; Gale, A. S.; Attree, K.; Jenkyns, H. C.

    2016-06-01

    High-resolution records of bulk carbonate carbon isotopes have been generated for the Upper Coniacian to Lower Campanian interval of the sections at Seaford Head (southern England) and Bottaccione (central Italy). An unambiguous stratigraphic correlation is presented for the base and top of the Santonian between the Boreal and Tethyan realms. Orbital forcing of carbon and oxygen isotopes at Seaford Head points to the Boreal Santonian spanning five 405 kyr cycles (Sa1 to Sa5). Correlation of the Seaford Head time scale to that of the Niobrara Formation (Western Interior Basin) permits anchoring these records to the La2011 astronomical solution at the Santonian-Campanian (Sa/Ca) boundary, which has been recently dated to 84.19 ± 0.38 Ma. Among the five tuning options examined, option 2 places the Sa/Ca at the 84.2 Ma 405 kyr insolation minimum and appears as the most likely. This solution indicates that minima of the 405 kyr filtered output of the resistivity in the Niobrara Formation correlate to 405 kyr insolation minima in the astronomical solution and to maxima in the filtered δ13C of Seaford Head. We suggest that variance in δ13C is driven by climate forcing of the proportions of CaCO3 versus organic carbon burial on land and in oceanic basins. The astronomical calibration generates a 200 kyr mismatch of the Coniacian-Santonian boundary age between the Boreal Realm in Europe and the Western Interior, due either to diachronism of the lowest occurrence of the inoceramid Cladoceramus undulatoplicatus between the two regions or to remaining uncertainties of radiometric dating and cyclostratigraphic records.

  13. Echelle spectrograph calibration with a frequency comb based on a harmonically mode-locked fiber laser: a proposal

    International Nuclear Information System (INIS)

    Details for constructing an astronomical frequency comb suitable as a wavelength reference for echelle spectrographs associated with optical telescopes are outlined. The source laser for the frequency comb is a harmonically mode-locked fiber laser with a central wavelength of 1.56 μm. The means of producing a repetition rate greater than 7 GHz and a peak optical power of ∼8 kW are discussed. Conversion of the oscillator light into the visible can occur through a two-step process of (i) nonlinear conversion in periodically poled lithium niobate and (ii) spectral broadening in photonic crystal fiber. While not necessarily octave spanning in spectral range to permit the use of an f -to- 2f interferometer for offset frequency control, the frequency comb can be granted accuracy by linking the mode spacing and a comb tooth to separate frequency references. The design avoids the use of a Fabry-Perot cavity to increase the mode spacing of the frequency comb; however, the level of supermode suppression and sideband asymmetry in the fiber oscillator and in the subsequent frequency conversion stages are aspects that need to be experimentally tested.

  14. Current Calibration Efforts and Performance of the HST Space Telescope Imaging Spectrograph: Echelle Flux Calibration, the BAR5 Occulter, and Lamp Lifetimes

    Science.gov (United States)

    Monroe, TalaWanda R.; Aloisi, Alessandra; Debes, John H.; Jedrzejewski, Robert I.; Lockwood, Sean A.; Peeples, Molly S.; Proffitt, Charles R.; Riley, Allyssa; Walborn, Nolan R.

    2016-06-01

    The variety of operating modes of the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) continues to allow STIS users to obtain unique, high quality observations and cutting-edge results 19 years after its installation on HST. STIS is currently the only instrument available to the astronomy community that allows high spectral and spatial resolution spectroscopy in the FUV and NUV, including echelle modes. STIS also supports solar-blind imaging in the FUV. In the optical, STIS provides long-slit, first-order spectra that take advantage of HST's superb spatial resolution, as well as several unique unfiltered coronagraphic modes, which continue to benefit the exoplanet and debris-disk communities. The STIS instrument team monitors the instrument’s health and performance over time to characterize the effects of radiation damage and continued use of the detectors and optical elements. Additionally, the STIS team continues to improve the quality of data products for the user community. We present updates on efforts to improve the echelle flux calibration of overlapping spectral orders due to changes in the grating blaze function since HST Servicing Mission 4, and efforts to push the contrast limit and smallest inner working angle attainable with the coronagraphic BAR5 occulter. We also provide updates on the performance of the STIS calibration lamps, including work to maintain the accuracy of the wavelength calibration for all modes.

  15. Spectro-photometric calibration of the SuperNova Integral Field Spectrograph in the Nearby Supernova Factory collaboration framework

    International Nuclear Information System (INIS)

    Ten years ago, type Ia supernovae used as distances indicators led to the discovery of the accelerating expansion of the universe. Today, a second generation of surveys has significantly increased the high-redshift type Ia supernovae sample. The low-redshift sample was however still limiting the cosmological analysis using SNe. In this framework, the Nearby Supernova Factory has followed 200 nearby type Ia supernovae using the dedicated Supernovae Integral Field Spectrograph with spectro-photometric capacities. My PhD thesis has been carried out at the Institut de Physique Nucleaire de Lyon and at the Lawrence Berkeley National Laboratory in the framework of the international cosmological project SNfactory. In order to reach the design spectrophotometric accuracy, attention has been focused on several key aspects of the calibration procedure, including: determination of a dedicated point spread function for 3D point source extraction, estimating the nightly photometric quality, derivation of the nightly sky extinction over the extended optical domain, its modeling in terms of physical components and its variability within a given night. A full multi-standards calibration pipeline has been implemented using approximately 4000 observations of spectrophotometric standard stars taken throughout the night over nearly 500 individual nights. Preliminary scientific results of the whole SNfactory collaboration will be presented at the end of this thesis. (author)

  16. Astronomical calibration of Gauss to Matuyama sapropels in the Mediterranean and implication for the Geomagnetic Polarity Time Scale

    NARCIS (Netherlands)

    Hilgen, F.J.

    1991-01-01

    The late Pliocene-early Pleistocene sapropel-bearing sequences exposed in the Vrica, Semaforo, Singa and Punta Piccola sections of southern Italy and the Francocastello section on Crete have been calibrated to the new astronomical solutions for the precession of the equinox and the eccentricity of t

  17. Absolute calibration of a SPRED [Spectrometer Recording Extended Domain] EUV [extreme ultraviolet] spectrograph for use on the DIII-D tokamak

    International Nuclear Information System (INIS)

    We have performed an absolute intensity calibration of a SPRED multichannel EUV spectrograph using synchrotron radiation from the NBS SURF-II electron storage ring. The calibration procedure and results for both a survey grating (450 g/mm) and a high-resolution (2100 g/mm) grating are presented. The spectrograph is currently in use on the DIII-D tokamak with a tangential line-of-sight at the plasma midplane. Data is first acquired and processed by a microcomputer; the absolute line intensities are then sent to the DIII-D database for comparison with data from other diagnostics. Representative data from DIII-D plasma operations will be presented. 6 refs., 3 figs., 1 tab

  18. Astronomical calibration of the Boreal Santonian (Cretaceous) based on the marine carbon isotope record and correlation to the tropical realm

    Science.gov (United States)

    Thibault, Nicolas; Jarvis, Ian; Voigt, Silke; Gale, Andy; Attree, Kevin; Jenkyns, Hugh

    2016-04-01

    New high-resolution records of bulk carbonate carbon isotopes have been generated for the Upper Coniacian to Lower Campanian interval of the reference sections at Seaford Head (southern England) and Bottaccione (Gubbio, central Italy). These records allow for a new and unambiguous stratigraphic correlation of the base and top of the Santonian between the Boreal and Tethyan realms. Orbital forcing of stable carbon and oxygen isotopes can be highlighted in the Seaford Head dataset, and a floating astronomical time scale is presented for the Santonian of the section, which spans five 405 kyr cycles (Sa1 to Sa5). Macro-, micro- and nannofossil biostratigraphy of the Seaford section is integrated along with magnetostratigraphy, carbon-isotope chemostratigraphy and cyclostratigraphy. Correlation of the Seaford Head astronomical time scale to that of the Niobrara Formation (U.S. Western Interior Basin) allows for anchoring these records to the La2011 astronomical solution at the Santonian-Campanian (Sa/Ca) boundary, which has been recently dated to 84.19±0.38 Ma. Five different astronomical tuning options are examined. The astronomical calibration generates a c. 200 kyr mismatch of the Coniacian-Santonian boundary age between the Boreal Realm in Europe and the Western Interior, likely due either to slight diachronism of the first occurrence of the inoceramid Cladoceramus undulatoplicatus between the two regions, or to remaining uncertainties of radiometric dating and the cyclostratigraphic records.

  19. Astronomical calibration of Gauss to Matuyama sapropels in the Mediterranean and implication for the Geomagnetic Polarity Time Scale

    OpenAIRE

    Hilgen, F. J.

    1991-01-01

    The late Pliocene-early Pleistocene sapropel-bearing sequences exposed in the Vrica, Semaforo, Singa and Punta Piccola sections of southern Italy and the Francocastello section on Crete have been calibrated to the new astronomical solutions for the precession of the equinox and the eccentricity of the Earth's orbit using inferred phase relationships between these orbital cycles and the sapropel cycles. A new Mediterranean Precession-Related Sapropel (MPRS) coding is introduced according to wh...

  20. Support for the Astronomically Calibrated 40Ar/39Ar Age of Fish Canyon Sanidine

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Storey, Michael; Zeeden, Christian;

    2011-01-01

    intercalated in the direct astronomically tuned Faneromeni section on Crete. The tuning of this section was achieved through correlations to long (400kyr) and short (100kyr) eccentricity cycles, followed by tuning of sedimentary cycles to precession and summer insolation by applying the La2004(1,1) orbital...

  1. Supporting Evidence for the Astronomically Calibrated Age of Fish Canyon Sanidine

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Storey, Michael; Zeeden, Christian;

    . The direct tuning of this section was achieved through correlation to long (~400-kyr) and short (~100-kyr) eccentricity, followed by tuning - of basic sedimentary cycles - to precession and summer insolation, using the La2004(1,1) astronomical solution (Laskar, et al., 2004). We employed a Nu Instruments...

  2. A Refined Astronomically Calibrated 40Ar/39Ar Age for Fish Canyon Sanidine

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Storey, Michael; Zeeden, Christian;

    2011-01-01

    , but more precise (±0.10%) than, the previous 40Ar/39Ar age determined by intercalibration with astronomically tuned tephras from the Melilla Basin (Morocco). Using this proposed age for FCs, combined with measurements using the A1Ts as the neutron fluence monitor, a weighted mean Bishop Tuff 40Ar/39Ar...

  3. A refined astronomically calibrated 40Ar/39Ar age for Fish Canyon sanidine

    NARCIS (Netherlands)

    Rivera, T.A.; Storey, M.; Zeeden, C.; Hilgen, F.J.; Kuiper, K.

    2011-01-01

    Intercalibration between the astronomical and radio-isotopic dating methods provides a means to improving accuracy and reducing uncertainty of an integrated, multi-chronometer geologic timescale. Here we report a high-precision 40Ar/39Ar age for the FishCanyon sanidine (FCs) neutron fluence monitor,

  4. Laser frequency comb techniques for precise astronomical spectroscopy

    CERN Document Server

    Murphy, Michael T; Light, Philip S; Luiten, Andre N; Lawrence, Jon S

    2012-01-01

    Precise astronomical spectroscopic analyses routinely assume that individual pixels in charge-coupled devices (CCDs) have uniform sensitivity to photons. Intra-pixel sensitivity (IPS) variations may already cause small systematic errors in, for example, studies of extra-solar planets via stellar radial velocities and cosmological variability in fundamental constants via quasar spectroscopy, but future experiments requiring velocity precisions approaching ~1 cm/s will be more strongly affected. Laser frequency combs have been shown to provide highly precise wavelength calibration for astronomical spectrographs, but here we show that they can also be used to measure IPS variations in astronomical CCDs in situ. We successfully tested a laser frequency comb system on the Ultra-High Resolution Facility spectrograph at the Anglo-Australian Telescope. By modelling the 2-dimensional comb signal recorded in a single CCD exposure, we find that the average IPS deviates by <8 per cent if it is assumed to vary symmetri...

  5. Replicated Spectrographs in Astronomy

    CERN Document Server

    Hill, Gary J

    2014-01-01

    As telescope apertures increase, the challenge of scaling spectrographic astronomical instruments becomes acute. The next generation of extremely large telescopes (ELTs) strain the availability of glass blanks for optics and engineering to provide sufficient mechanical stability. While breaking the relationship between telescope diameter and instrument pupil size by adaptive optics is a clear path for small fields of view, survey instruments exploiting multiplex advantages will be pressed to find cost-effective solutions. In this review we argue that exploiting the full potential of ELTs will require the barrier of the cost and engineering difficulty of monolithic instruments to be broken by the use of large-scale replication of spectrographs. The first steps in this direction have already been taken with the soon to be commissioned MUSE and VIRUS instruments for the Very Large Telescope and the Hobby-Eberly Telescope, respectively. MUSE employs 24 spectrograph channels, while VIRUS has 150 channels. We compa...

  6. GRACES: Gemini remote access to CFHT ESPaDOnS Spectrograph through the longest astronomical fiber ever made (Experimental phase completed.)

    CERN Document Server

    Chené, André-Nicolas; Barrick, Gregory; Anthony, Andre; Benedict, Tom; Duncan, David; Gigoux, Pedro; Kleinman, Scot; Malo, Lison; Martioli, Eder; Moutou, Claire; Placco, Vinicius; Reshetovand, Vlad; Rhee, Jaehyon; Roth, Katherine; Schiavon, Ricardo P; Tollestrup, Eric; Vermeulen, Tom; White, John; Wooff, Robert

    2014-01-01

    The Gemini Remote Access to CFHT ESPaDONS Spectrograph has achieved first light of its experimental phase in May 2014. It successfully collected light from the Gemini North telescope and sent it through two 270 m optical fibers to the the ESPaDOnS spectrograph at CFHT to deliver high-resolution spectroscopy across the optical region. The fibers gave an average focal ratio degradation of 14% on sky, and a maximum transmittance of 85% at 800nm. GRACES achieved delivering spectra with a resolution power of R = 40,000 and R = 66,000 between 400 and 1,000 nm. It has a ~8% throughput and is sensitive to target fainter than 21st mag in 1 hour. The average acquisition time of a target is around 10 min. This project is a great example of a productive collaboration between two observatories on Maunakea that was successful due to the reciprocal involvement of the Gemini, CFHT, and NRC Herzberg teams, and all the staff involved closely or indirectly.

  7. GRACES: Gemini remote access to CFHT ESPaDOnS spectrograph through the longest astronomical fiber ever made: experimental phase completed

    Science.gov (United States)

    Chene, André-Nicolas; Padzer, John; Barrick, Gregory; Anthony, Andre; Benedict, Tom; Duncan, Dave; Gigoux, Pedro; Kleinman, Scot; Malo, Lison; Martioli, Eder; Moutou, Claire; Placco, Vinicius; Reshetovand, Vladimir; Rhee, Jaehyon; Roth, Katherine; Schiavon, Ricardo; Tollestrup, Eric V.; Vermeulen, Tom A.; White, John; Wooff, Robert

    2014-07-01

    The Gemini Remote Access to CFHT ESPaDONS Spectrograph has achieved first light of its experimental phase in May 2014. It successfully collected light from the Gemini North telescope and sent it through two 270 m optical fibers to the the ESPaDOnS spectrograph at CFHT to deliver high-resolution spectroscopy across the optical region. The fibers gave an average focal ratio degradation of 14% on sky, and a maximum transmittance of 85% at 800nm. GRACES achieved delivering spectra with a resolution power of R = 40,000 and R = 66,000 between 400 and 1,000 nm. It has a ~8% throughput and is sensitive to target fainter than 21st mag in 1 hour. The average acquisition time of a target is around 10 min. This project is a great example of a productive collaboration between two observatories on Maunakea that was successful due to the reciprocal involvement of the Gemini, CFHT, and NRC Herzberg teams, and all the staff involved closely or indirectly.

  8. SparsePak: A Formatted Fiber Field Unit for The WIYN Telescope Bench Spectrograph. I. Design, Construction, and Calibration

    CERN Document Server

    Bershady, M A; Harker, J; Ramsey, L W; Verheijen, M A W

    2004-01-01

    We describe the design and construction of a formatted fiber field-unit, SparsePak, and characterize its optical and astrometric performance. This array is optimized for spectroscopy of low-surface brightness, extended sources in the visible and near-infrared. SparsePak contains 82, 4.7" fibers subtending an area of 72"x71" in the telescope focal plane, and feeds the WIYN Bench spectrograph. Together, these instruments are capable of achieving spectral resolutions of lambda/dlambda ~ 20000 and an area--solid-angle product of ~140 arcsec^2 m^2 per fiber. Laboratory measurements of SparsePak lead to several important conclusions on the design of fiber termination and cable curvature to minimize focal ratio degradation. SparsePak itself has throughput >80% redwards of 5200 A, and 90-92% in the red. Fed at f/6.3, the cable delivers an output 90% encircled energy at nearly f/5.2. This has implications for performance gains if the WIYN Bench Spectrograph had a faster collimator. Our approach to integral-field spect...

  9. Calibration of radio-astronomical data on the cloud. LOFAR, the pathway to SKA

    Science.gov (United States)

    Sabater, J.; Sánchez-Expósito, S.; Garrido, J.; Ruiz, J. E.; Best, P. N.; Verdes-Montenegro, L.

    2015-05-01

    The radio interferometer LOFAR (LOw Frequency ARray) is fully operational now. This Square Kilometre Array (SKA) pathfinder allows the observation of the sky at frequencies between 10 and 240 MHz, a relatively unexplored region of the spectrum. LOFAR is a software defined telescope: the data is mainly processed using specialized software running in common computing facilities. That means that the capabilities of the telescope are virtually defined by software and mainly limited by the available computing power. However, the quantity of data produced can quickly reach huge volumes (several Petabytes per day). After the correlation and pre-processing of the data in a dedicated cluster, the final dataset is handled to the user (typically several Terabytes). The calibration of these data requires a powerful computing facility in which the specific state of the art software under heavy continuous development can be easily installed and updated. That makes this case a perfect candidate for a cloud infrastructure which adds the advantages of an on demand, flexible solution. We present our approach to the calibration of LOFAR data using Ibercloud, the cloud infrastructure provided by Ibergrid. With the calibration work-flow adapted to the cloud, we can explore calibration strategies for the SKA and show how private or commercial cloud infrastructures (Ibercloud, Amazon EC2, Google Compute Engine, etc.) can help to solve the problems with big datasets that will be prevalent in the future of astronomy.

  10. Extension of the astronomically calibrated (polarity) time scale to the Miocene/Pliocene boundary

    NARCIS (Netherlands)

    Hilgen, F.J.

    1991-01-01

    The early Pleistocene to late Pliocene astronormcally calibrated time scale of Shackleton et al. [1] and Hllgen [2] is extended to the Mlocene/Pllocene boundary This is done by correlating the detailed record of CaCO 3 cycles in the Trubl and the lower part of the overlying Narbone Formation (Rossel

  11. New method for atmospheric calibration at the Pierre Auger Observatory using FRAM, a robotic astronomical telescope

    CERN Document Server

    BenZvi, Segev; Connolly, Brian; Grygar, Jiri; Hrabovsky, Miroslav; Karova, Tatiana; Mandat, Dusan; Necesal, Petr; Nosek, Dalibor; Nozka, Libor; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Ridky, Jan; Schovanek, Petr; Smida, Radomir; Travnicek, Petr; Vitale, Primo; Westerhoff, Stefan

    2007-01-01

    FRAM - F/(Ph)otometric Robotic Atmospheric Monitor is the latest addition to the atmospheric monitoring instruments of the Pierre Auger Observatory. An optical telescope equipped with CCD camera and photometer, it automatically observes a set of selected standard stars and a calibrated terrestrial source. Primarily, the wavelength dependence of the attenuation is derived and the comparison between its vertical values (for stars) and horizontal values (for the terrestrial source) is made. Further, the integral vertical aerosol optical depth can be obtained. A secondary program of the instrument, the detection of optical counterparts of gamma-ray bursts, has already proven successful. The hardware setup, software system, data taking procedures, and first analysis results are described in this paper.

  12. New method for atmospheric calibration at the Pierre Auger Observatory using FRAM, a robotic astronomical telescope

    Science.gov (United States)

    Trávníček, Petr; Benzvi, Segev; Boháčová, Martina; Connolly, Brian; Grygar, Jiří; Hrabovský, Miroslav; Kárová, Tatiana; Mandát, Dušan; Nečesal, Petr; Nosek, Dalibor; Nožka, Libor; Palatka, Miroslav; sPech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Šmída, Radomír; Vitale, Primo; Westerhoff, Stefan

    FRAM - F/(Ph)otometric Robotic Atmospheric Monitor is the latest addition to the atmospheric monitoring instruments of the Pierre Auger Observatory. An optical telescope equipped with CCD camera and photometer, it automatically observes a set of selected standard stars and a calibrated terrestrial source. Primarily, the wavelength dependence of the attenuation is derived and the comparison between its vertical values (for stars) and horizontal values (for the terrestrial source) is made. Further, the integral vertical aerosol optical depth can be obtained. A secondary program of the instrument, the detection of optical counterparts of gamma-ray bursts, has already proven successful. The hardware setup, software system, data taking procedures, and first analysis results are described in this paper.

  13. ECHARPE: a fiber-fed echelle spectrograph for the Pico dos Dias Observatory

    Science.gov (United States)

    Dominici, Tania P.; Castilho, Bruno; Gneiding, Clemens D.; Delabre, Bernard A.; Macanhan, Vanessa B. P.; de Arruda, Marcio V.; de Oliveira, Antonio C.; Melendez, Jorge; Vaz, Luiz P. R.; Corradi, Wagner J. B.; Franco, Gabriel A. P.; do Nascimento, Jose D.; Quast, Germano R.; Porto de Mello, Gustavo F.

    2012-09-01

    At least during the last ten years, the Brazilian astronomical community has been asking for an echelle spectrograph for the 1.6 m telescope installed at Pico dos Dias Observatory (Brazópolis, MG, Brazil, OPD/MCTI/LNA). Among the scientific cases are topics related to the chemical evolution of the Galaxy, asteroseismology, chemical composition and chromospheric activities of solar type stars and the relations between solar analogues and terrestrial planets. During 2009 the project finally got started. The called ECHARPE spectrograph (Espectrógrafo ECHelle de Alta Resolução para o telescópio Perkin-Elmer) is being projected to offer a spectral resolution of R ~ 50000, in the range 390-900 nm and with a single exposition. It will be a bench spectrograph with two channels: blue and red, fed by two optical fibers (object, sky or calibration) with aperture of 1.5 or 2.0 arcseconds. The instrument will be placed in one of the telescope pillar ramification, in the originals installations of a Coudé spectrograph and in a specially created environment controlled room. In this work we will present the scientific motivations, the conceptual optical design, the expected performance of the spectrograph, and the status of its development. ECHARPE is expected to be delivered to the astronomical community in 2014, fully prepared and optimized for remote operations.

  14. Direct high-precision U-Pb geochronology of the end-Cretaceous extinction and calibration of Paleocene astronomical timescales

    Science.gov (United States)

    Clyde, William C.; Ramezani, Jahandar; Johnson, Kirk R.; Bowring, Samuel A.; Jones, Matthew M.

    2016-10-01

    The Cretaceous-Paleogene (K-Pg) boundary is the best known and most widely recognized global time horizon in Earth history and coincides with one of the two largest known mass extinctions. We present a series of new high-precision uranium-lead (U-Pb) age determinations by the chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) method from volcanic ash deposits within a tightly constrained magnetobiostratigraphic framework across the K-Pg boundary in the Denver Basin, Colorado, USA. This new timeline provides a precise interpolated absolute age for the K-Pg boundary of 66.021 ± 0.024 / 0.039 / 0.081 Ma, constrains the ages of magnetic polarity Chrons C28 to C30, and offers a direct and independent test of early Paleogene astronomical and 40Ar/39Ar based timescales. Temporal calibration of paleontological and palynological data from the same deposits shows that the interval between the extinction of the dinosaurs and the appearance of earliest Cenozoic mammals in the Denver Basin lasted ∼185 ky (and no more than 570 ky) and the 'fern spike' lasted ∼1 ky (and no more than 71 ky) after the K-Pg boundary layer was deposited, indicating rapid rates of biotic extinction and initial recovery in the Denver Basin during this event.

  15. Astronomical Polarimetry

    Science.gov (United States)

    Tinbergen, Jaap

    1996-09-01

    This handy volume provides a clear, comprehensive and concise introduction to astronomical polarimetry at all wavelengths. Starting from first principles and a simple physical picture of polarized radiation, the author introduces the reader to all the key topics, including Stokes parameters, applications of polarimetry in astronomy, polarization algebra, polarization errors and calibration methods, and a selection of instruments (from radio to X-ray). The author rounds off the book with a number of useful case studies, a collection of exercises, an extensive list of further reading and an informative index. This review of all aspects of astronomical polarization provides both an essential introduction for graduate students, and a valuable reference for practicing astronomers.

  16. WES - Weihai Echelle Spectrograph

    CERN Document Server

    Gao, Dong-Yang; Cao, Chen; Hu, Shao-Ming; Wittenmyer, Robert A; Hu, Zhong-Wen; Grupp, Frank; Kellermann, Hanna; Li, Kai; Guo, Di-Fu

    2016-01-01

    The Weihai Echelle Spectrograph (WES) is the first fiber-fed echelle spectrograph for astronomical observation in China. It is primarily used for chemical abundance and asteroseismology studies of nearby bright stars, as well as radial velocity detections for exoplanets. The optical design of WES is based on the widely demonstrated and well-established white-pupil concept. We describe the WES in detail and present some examples of its performance. A single exposure echelle image covers the spectral region 371-1,100 nm in 107 spectral orders over the rectangular CCD. The spectral resolution $R=\\lambda/\\Delta\\lambda$ changes from 40,600 to 57,000 through adjusting the entrance slit width from full to 2.2 pixels sampling at the fiber-exit. The limiting magnitude scales to $V=8$ with a signal-to-noise ratio (SNR) of more than 100 in $V$ for an hour exposure, at the spectral resolution R$\\approx$40,000 in the median seeing of 1.7$^{\\prime\\prime}$ at Weihai Observatory (WHO) for the 1-meter telescope. The radial ve...

  17. American West Tephras – Geomagnetic polarity events redefined through calibration of radio-isotopic and astronomical time

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Storey, Michael

    with the astronomical age of the Cobb Mountain event, independently determined through correlation of oxygen isotopes in a piston core (Horng, et al. 2002). Two other ash flows in the American west were analyzed: the Bishop and the Huckleberry Ridge Tuffs. Multi-crystal sanidine experiments of the Bishop Tuff provide...

  18. The re-flight of the Colorado high-resolution Echelle stellar spectrograph (CHESS): improvements, calibrations, and post-flight results

    CERN Document Server

    Hoadley, Keri; Kruczek, Nicholas; Fleming, Brian; Nell, Nicholas; Kane, Robert; Swanson, Jack; Green, James; Erickson, Nicholas; Wilson, Jacob

    2016-01-01

    In this proceeding, we describe the scientific motivation and technical development of the Colorado High-resolution Echelle Stellar Spectrograph (CHESS), focusing on the hardware advancements and testing supporting the second flight of the payload (CHESS-2). CHESS is a far ultraviolet (FUV) rocket-borne instrument designed to study the atomic-to-molecular transitions within translucent cloud regions in the interstellar medium (ISM). CHESS is an objective f/12.4 echelle spectrograph with resolving power $>$ 100,000 over the band pass 1000 $-$ 1600 {\\AA}. The spectrograph was designed to employ an R2 echelle grating with "low" line density. We compare the FUV performance of experimental echelle etching processes (lithographically by LightSmyth, Inc. and etching via electron-beam technology by JPL Microdevices Laboratory) with traditional, mechanically-ruled gratings (Bach Research, Inc. and Richardson Gratings). The cross-dispersing grating, developed and ruled by Horiba Jobin-Yvon, is a holographically-ruled, ...

  19. Suppression of Fiber Modal Noise Induced Radial Velocity Errors for Bright Emission-Line Calibration Sources

    CERN Document Server

    Mahadevan, Suvrath; Ramsey, Lawrence; Venditti, Nick

    2014-01-01

    Modal noise in optical fibers imposes limits on the signal to noise and velocity precision achievable with the next generation of astronomical spectrographs. This is an increasingly pressing problem for precision radial velocity (RV) spectrographs in the near-infrared (NIR) and optical that require both high stability of the observed line profiles and high signal to noise. Many of these spectrographs plan to use highly coherent emission line calibration sources like laser frequency combs and Fabry-Perot etalons to achieve precision sufficient to detect terrestrial mass planets. These high precision calibration sources often use single mode fibers or highly coherent sources. Coupling light from single mode fibers to multi-mode fibers leads to only a very low number of modes being excited, thereby exacerbating the modal noise measured by the spectrograph. We present a commercial off-the-shelf (COTS) solution that significantly mitigates modal noise at all optical and NIR wavelengths, and which can be applied to...

  20. A new Generation of Spectrometer Calibration Techniques based on Optical Frequency Combs

    CERN Document Server

    Schmidt, Piet O; Kimeswenger, Stefan

    2007-01-01

    Typical astronomical spectrographs have a resolution ranging between a few hundred to 200.000. Deconvolution and correlation techniques are being employed with a significance down to 1/1000 th of a pixel. HeAr and ThAr lamps are usually used for calibration in low and high resolution spectroscopy, respectively. Unfortunately, the emitted lines typically cover only a small fraction of the spectrometer's spectral range. Furthermore, their exact position depends strongly on environmental conditions. A problem is the strong intensity variation between different (intensity ratios {>300). In addition, the brightness of the lamps is insufficient to illuminate a spectrograph via an integrating sphere, which in turn is important to calibrate a long-slit spectrograph, as this is the only way to assure a uniform illumination of the spectrograph pupil. Laboratory precision laser spectroscopy has experienced a major advance with the development of optical frequency combs generated by pulsed femto-second lasers. These lase...

  1. High Dispersion Spectroscopy with Ond\\v{r}ejov Echelle Spectrograph

    CERN Document Server

    Grossová, Romana

    2016-01-01

    Echelle spectrographs with their high resolution plays important role in determination of characteristics of stellar lines. Wide field of applications is focused mainly on the measurements of precise radial velocity applied in exoplanetary research. In my diploma thesis I am concentrated on the calibration of the Ond\\v{r}ejov Echelle Spectrograph at Astronomical Institute of the Czech Academy of Sciences. My role was to investigate the wide field of opportunities how to process the data with the best possible results. Successful reduction was performed by both Image Reduction and Analysis Facility (IRAF) and for Open source Pipeline for ESPaDOnS Reduction and Analysis. This thesis includes the comparison of both pipelines.

  2. Suppression of Fiber Modal Noise Induced Radial Velocity Errors for Bright Emission-line Calibration Sources

    Science.gov (United States)

    Mahadevan, Suvrath; Halverson, Samuel; Ramsey, Lawrence; Venditti, Nick

    2014-05-01

    Modal noise in optical fibers imposes limits on the signal-to-noise ratio (S/N) and velocity precision achievable with the next generation of astronomical spectrographs. This is an increasingly pressing problem for precision radial velocity spectrographs in the near-infrared (NIR) and optical that require both high stability of the observed line profiles and high S/N. Many of these spectrographs plan to use highly coherent emission-line calibration sources like laser frequency combs and Fabry-Perot etalons to achieve precision sufficient to detect terrestrial-mass planets. These high-precision calibration sources often use single-mode fibers or highly coherent sources. Coupling light from single-mode fibers to multi-mode fibers leads to only a very low number of modes being excited, thereby exacerbating the modal noise measured by the spectrograph. We present a commercial off-the-shelf solution that significantly mitigates modal noise at all optical and NIR wavelengths, and which can be applied to spectrograph calibration systems. Our solution uses an integrating sphere in conjunction with a diffuser that is moved rapidly using electrostrictive polymers, and is generally superior to most tested forms of mechanical fiber agitation. We demonstrate a high level of modal noise reduction with a narrow bandwidth 1550 nm laser. Our relatively inexpensive solution immediately enables spectrographs to take advantage of the innate precision of bright state-of-the art calibration sources by removing a major source of systematic noise.

  3. Comb-calibrated solar spectroscopy through a multiplexed single-mode fiber channel

    CERN Document Server

    Probst, R A; Doerr, H-P; Steinmetz, T; Kentischer, T J; Zhao, G; Hänsch, T W; Udem, Th; Holzwarth, R; Schmidt, W

    2015-01-01

    We investigate a new scheme for astronomical spectrograph calibration using the laser frequency comb at the Solar Vacuum Tower Telescope on Tenerife. Our concept is based upon a single-mode fiber channel, that simultaneously feeds the spectrograph with comb light and sunlight. This yields nearly perfect spatial mode matching between the two sources. In combination with the absolute calibration provided by the frequency comb, this method enables extremely robust and accurate spectroscopic measurements. The performance of this scheme is compared to a sequence of alternating comb and sunlight, and to absorption lines from Earth's atmosphere. We also show how the method can be used for radial-velocity detection by measuring the well-explored 5-minute oscillations averaged over the full solar disk. Our method is currently restricted to solar spectroscopy, but with further evolving fiber-injection techniques it could become an option even for faint astronomical targets.

  4. A high-resolution Fourier transform spectrometer for astronomical observations and development of wavelength standards

    Science.gov (United States)

    Lemke, Ulrike; Reiners, Ansgar; Schäfer, Sebastian

    2012-09-01

    At the Institute for Astrophysics Goettingen (IAG), we are purchasing a high resolution Fourier Transform Spectrograph (FTS) for astronomical observations and development of calibration standards aiming at high wavelength precision. Astronomical spectrographs that work in the regime of very high resolution (resolving powers λ/δλ>=105) now achieve unprecedented precision and stability. Precise line shifts can be investigated to conclude for an objects radial velocity relative to the observer. As a long-term scientific goal, the evolution of galaxy redshift due to dark energy can be monitored. Also, the detection of lower mass, down to Earth-like planets will become feasible. Here, M-dwarfs are promising objects where an orbiting exo-Earth can cause a wavelength shift large enough to be detected. Emitting mainly in the near infrared (NIR), these objects require novel calibration standards. Current schemes under consideration are gas cathode lamps (e.g. CN, UNe) and a highly stable Fabry-Perot interferometer (FPI) to act as a cost-efficient alternative to the laser frequency comb (LFC, [1]). In addition to experiments exploring novel wavelength calibration types, light will be fed from our telescopes at IAG. A Vacuum Tower Telescope (VTT) for solar observations and the 50 cm Cassegrain telescope allow to investigate stellar and spatially resolved light at our facilities.

  5. Design and Construction of VUES: the Vilnius University Echelle Spectrograph

    CERN Document Server

    Jurgenson, Colby; McCracken, Tyler; Sawyer, David; Szymkowiak, Andrew; Giguere, Matt; Santoro, Fernando; Muller, Gary

    2016-01-01

    In February of 2014 the Yale Exoplanet Laboratory was commissioned to design, build, and deliver a high resolution (R = 60,000) spectrograph for the 1.65-meter telescope at the Moletai Astronomical Observatory. The observatory is operated by the Institute of Theoretical Physics and Astronomy at Vilnius University. The Vilnius University Echelle Spectrograph (VUES) is a white-pupil design that is fed via an octagonal fiber from the telescope and has an operational bandpass from 400 to 880 nm. VUES incorporates a novel modular optomechanical design that allows for quick assembly and alignment on commercial optical tables. This approach allowed the spectrograph to be assembled and commissioned at Yale using lab optical tables and then reassembled at the observatory on a different optical table with excellent repeatability. The assembly and alignment process for the spectrograph was reduced to a few days, allowing the spectrograph to be completely disassembled for shipment to Lithuania, and then installed at the ...

  6. Astronomical Cybersketching

    CERN Document Server

    Grego, Peter

    2009-01-01

    Outlines the techniques involved in making observational sketches and more detailed 'scientific' drawings of a wide variety of astronomical subjects using modern digital equipment; primarily PDAs and tablet PCs. This book also discusses about choosing hardware and software

  7. Multiple object fiber optics spectrograph feed for the Hale telescope

    Science.gov (United States)

    Tubbs, E. F.; Goss, W. C.; Cohen, J. G.

    1982-01-01

    The preliminary design for a computer-controlled fiber-optics feed linking the 5-m Hale telescope at Palomar Observatory to the entrance slit of an astronomical spectrograph is presented. A 76-mm square field will be divided into ten strips containing two movable fibers each; the fibers can be moved by stepper-motor-driven lead screws to any position on the strip. The device is designed to allow the simultaneous spectrographic observation of many astronomical objects in a small angular field. A prototype feed using two fibers and manually commanded digital control is described in detail. Test observations of two bright O stars made in April, 1981 using the prototype with the Hale telescope are considered sufficiently positive to warrant construction of the 20-fiber feed, which would enhance the spectrographic-survey effectiveness of the telescope by a factor of ten.

  8. NRES: The Network of Robotic Echelle Spectrographs

    Science.gov (United States)

    Siverd, Robert; Brown, Timothy M.; Henderson, Todd; Hygelund, John; Tufts, Joseph; Eastman, Jason; Barnes, Stuart; Van Eyken, Julian C.

    2016-06-01

    Las Cumbres Observatory Global Network (LCOGT) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by up to two 1-meter telescopes and a thorium argon calibration source. We plan to install one at up to 6 observatory sites in the Northern and Southern hemispheres, creating a single, globally-distributed, autonomous spectrograph facility using up to twelve 1-m telescopes. Simulations suggest we will achieve long-term radial velocity precision of 3 m/s in less than an hour for stars brighter than V = 12. We have been funded with NSF MRI and ATI grants, and expect to deploy the first spectrograph in fall 2016, with the full network operation of 5 or 6 units beginning in 2017. We will briefly overview the NRES design, goals, robotic operation, and status. In addition, we will discuss early results from our prototype spectrograph, the laboratory and on-sky performance of our first production unit, initial science results, and the ongoing software development effort to bring this resource online.

  9. Astronomical Observatory

    Directory of Open Access Journals (Sweden)

    Mansi Khanna

    2014-03-01

    Full Text Available This photograph was taken at Jantar Mantar, one of India’s most famous astronomical observatories, located in Central Delhi. It was built in 1724 by Maharaja Jai Singh II of Jaipur, who then went on to build other observatories in Jaipur, Varanasi, and Mathura. It was used to make astronomical tables and predict movements of the planets and the sun. Its name is derived from yantra meaning instruments and mantar meaning formula.Due to the construction of several high rise buildings around the monument, it is no longer used for astronomical purposes. It however continues to be one of the biggest tourist attractions of the capital city. 

  10. Immersion echelle spectrograph

    Science.gov (United States)

    Stevens, Charles G.; Thomas, Norman L.

    2000-01-01

    A small spectrograph containing no moving components and capable of providing high resolution spectra of the mid-infrared region from 2 microns to 4 microns in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 10.sup.-5 cm.sup.2 sr. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first order transmission grating in a cross-dispersing configuration to provide a two-dimensional (2-D) spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a near aberration-free axially symmetric design. The spectrometer has wide use potential in addition to general research, such as monitoring atmospheric constituents for air quality, climate change, global warming, as well as monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

  11. PRISM Spectrograph Optical Design

    Science.gov (United States)

    Chipman, Russell A.

    1995-01-01

    The objective of this contract is to explore optical design concepts for the PRISM spectrograph and produce a preliminary optical design. An exciting optical configuration has been developed which will allow both wavelength bands to be imaged onto the same detector array. At present the optical design is only partially complete because PRISM will require a fairly elaborate optical system to meet its specification for throughput (area*solid angle). The most complex part of the design, the spectrograph camera, is complete, providing proof of principle that a feasible design is attainable. This camera requires 3 aspheric mirrors to fit inside the 20x60 cm cross-section package. A complete design with reduced throughput (1/9th) has been prepared. The design documents the optical configuration concept. A suitable dispersing prism material, CdTe, has been identified for the prism spectrograph, after a comparison of many materials.

  12. In-flight performance of the Goddard High Resolution Spectrograph of the Hubble Space Telescope

    Science.gov (United States)

    Troeltzsch, J.; Ebbets, D.; Garner, H.; Tuffli, A.; Breyer, R.; Kinsey, J.; Peck, C.; Lindler, D.; Feggans, J.

    1991-09-01

    The Goddard High Resolution Spectrograph (GHRS) has completed Orbital Verification and is well into the Science Verification phase of its mission. The instrument performance has been flawless, and many significant early science observations have been completed. The GHRS digicon detectors are well calibrated including the determination of operating parameters, detector geometry, and noise sensitivity. Tests using calibration lamps and standard UV stars have confirmed the instrument sensitivity and spectral resolving powers of Lambda/Delta-Lambda = 2000, 20,000, and 90,000. The sensitivity has not changed since the 1984 baseline ground based calibration. The GHRS flight software has been thoroughly tested, and is controlling all instrument observing as expected. Basic target acquisition testing and GHRS alignment calibrations have been successfully completed, and targets are routinely being located within 2-3 arcsecs of the initial pointing. Observations have been successfully performed using both the 2.0 x 2.0 arcsec aperture, and the smaller 0.25 x 0.25 arcsec aperture. The extended point spread function caused by the spherical aberration of the HST primary mirror has been well measured, and observing methods to deal with it have been developed. The aberrated image allows approximately 70 percent of the total energy into the large science aperture, and 15 percent of the total energy into the smaller aperture. Numerous science assessment observations of interesting astronomical targets have been completed, and indicate the extreme usefulness of the GHRS to the scientific community.

  13. LOTUS: A low cost, ultraviolet spectrograph

    OpenAIRE

    Steele, I. A.; Marchant, J. M.; Jermak, H. E.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Fitzsimmons, A.; Jehin, E.; Jones, G.; Mottram, C. J.; R.J. Smith; Snodgrass, C.; de Val-Borro, M.

    2016-01-01

    We describe the design, construction and commissioning of LOTUS; a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5x95 arcsec) and wide (5x25 arcsec) options that are optimized for spectral resolution and flux calibration respectively. On sky ...

  14. Astronomical Ecosystems

    Science.gov (United States)

    Neuenschwander, D. E.; Finkenbinder, L. R.

    2004-05-01

    Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical ecosystems," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.

  15. Single Mode, Extreme Precision Doppler Spectrographs

    Science.gov (United States)

    Schwab, Christian; Leon-Saval, Sergio G.; Betters, Christopher H.; Bland-Hawthorn, Joss; Mahadevan, Suvrath

    2014-04-01

    The `holy grail' of exoplanet research today is the detection of an earth-like planet: a rocky planet in the habitable zone around a main-sequence star. Extremely precise Doppler spectroscopy is an indispensable tool to find and characterize earth-like planets; however, to find these planets around solar-type stars, we need nearly one order of magnitude better radial velocity (RV) precision than the best current spectrographs provide. Recent developments in astrophotonics (Bland-Hawthorn & Horton 2006, Bland-Hawthorn et al. 2010) and adaptive optics (AO) enable single mode fiber (SMF) fed, high resolution spectrographs, which can realize the next step in precision. SMF feeds have intrinsic advantages over multimode fiber or slit coupled spectrographs: The intensity distribution at the fiber exit is extremely stable, and as a result the line spread function of a well-designed spectrograph is fully decoupled from input coupling conditions, like guiding or seeing variations (Ihle et al. 2010). Modal noise, a limiting factor in current multimode fiber fed instruments (Baudrand & Walker 2001), can be eliminated by proper design, and the diffraction limited input to the spectrograph allows for very compact instrument designs, which provide excellent optomechanical stability. A SMF is the ideal interface for new, very precise wavelength calibrators, like laser frequency combs (Steinmetz et al. 2008, Osterman et al. 2012), or SMF based Fabry-Perot Etalons (Halverson et al. 2013). At near infrared wavelengths, these technologies are ready to be implemented in on-sky instruments, or already in use. We discuss a novel concept for such a spectrograph.

  16. AIPY: Astronomical Interferometry in PYthon

    Science.gov (United States)

    Parsons, Aaron

    2016-09-01

    AIPY collects together tools for radio astronomical interferometry. In addition to pure-python phasing, calibration, imaging, and deconvolution code, this package includes interfaces to MIRIAD (ascl:1106.007) and HEALPix (ascl:1107.018), and math/fitting routines from SciPy.

  17. V. M. Slipher and the Development of the Nebular Spectrograph

    Science.gov (United States)

    Thompson, L. A.

    2013-04-01

    Vesto Melvin Slipher was the first astronomer to clearly define the factors that determine the “speed” of a nebular spectrograph. This brief historical summary recounts the way these ideas developed and how Slipher's early work on galaxy Doppler shifts was so quickly extended in the 1930s when Milton Humason and Edwin Hubble at Mt. Wilson Observatory began to push the velocity-distance relationship to such a depth that no one could doubt its cosmological significance.

  18. The Progress in High Precision Astronomical Radial Velocity Technique%高精度天体视向速度测量技术研究进展

    Institute of Scientific and Technical Information of China (English)

    姜明达; 肖东; 朱永田

    2012-01-01

    近年来,尽管对太阳系外行星探测的手段层出不穷,视向速度测量依然是探测太阳系外行星卓有成效的方法.随着探测太阳系外类地行星的呼声日益高涨,大幅度提高视向速度测量精度的任务迫在眉睫.为了提高天文光谱仪的稳定性,人们采用真空或恒温、恒压的仪器工作环境来确保视向速度的测量精度;同时,激光频率梳技术的出现又为天体视向速度测量系统提供了一个高精度的光谱定标源.将激光频率梳技术应用于天体视向速度测量是今后一段时间内的研究重点.%Discovering extrasolar planet has been pursued for a long time. Since the detection of the first extrasolar planet was reported two decades ago, over seven hundred extrasolar planets were reported. Although the new technique is emerging, the radial velocity measurement is still the most productive technique for extrasolar planet hunting. As the earth 'twin' is becoming the next goal, the precision of radial velocity measurement has to be dramatically improved. First of all, varies techniques were adopted to guarantee the stability of an astronomical spectrograph. One successful spectrograph is the HARPS, ESO operating in a vacuum tank. Another effort is put the spectrograph into a regulated instrument case whose temperature and air pressure are kept constant, like the PEPSI spectrograph. In the last decade, the laser frequency comb emerges as an ideal calibration source for the astronomical spectrograph. Based on a femtosecond laser referencing to a stable oscillator such as atomic clocks, the laser frequency comb could generate evenly distributed calibration lines in a wide spectral range with the precision of absolute frequencies better than 10-10. It would ensure the precision of radial velocity measurement achieving centimeters per second, much better than current precision, meter per second. As a broad range of laser frequency combs suitable for astronomical

  19. The Cosmic Origins Spectrograph

    CERN Document Server

    Green, James C; Osterman, Steve; Ebbets, Dennis; Heap, Sara H; Linsky, Claus Leitherer Jeffrey L; Savage, Blair D; Sembach, Kenneth; Shull, J Michael; Siegmund, Oswald H W; Snow, Theodore P; Spencer, John; Stern, S Alan; Stocke, John; Welsh, Barry; Beland, Stephane; Burgh, Eric B; Danforth, Charles; France, Kevin; Keeney, Brian; McPhate, Jason; Penton, Steven V; Andrews, John; Brownsberger, Kenneth; Morse, Jon; Wilkinson, Erik

    2011-01-01

    The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in May 2009, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F_lambda ~ 1.0E10-14 ergs/s/cm2/Angstrom, COS can achieve comparable signal to noise (when compared to STIS echelle modes) in 1-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (September 2009 - June 2011) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is 9 times that sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of June 2011....

  20. Micro photometer's automation for quantitative spectrograph analysis

    International Nuclear Information System (INIS)

    A Microphotometer is used to increase the sharpness of dark spectral lines. Analyzing these lines one sample content and its concentration could be determined and the analysis is known as Quantitative Spectrographic Analysis. The Quantitative Spectrographic Analysis is carried out in 3 steps, as follows. 1. Emulsion calibration. This consists of gauging a photographic emulsion, to determine the intensity variations in terms of the incident radiation. For the procedure of emulsion calibration an adjustment with square minimum to the data obtained is applied to obtain a graph. It is possible to determine the density of dark spectral line against the incident light intensity shown by the microphotometer. 2. Working curves. The values of known concentration of an element against incident light intensity are plotted. Since the sample contains several elements, it is necessary to find a work curve for each one of them. 3. Analytical results. The calibration curve and working curves are compared and the concentration of the studied element is determined. The automatic data acquisition, calculation and obtaining of resulting, is done by means of a computer (PC) and a computer program. The conditioning signal circuits have the function of delivering TTL levels (Transistor Transistor Logic) to make the communication between the microphotometer and the computer possible. Data calculation is done using a computer programm

  1. Construction and status of the CHARIS high contrast imaging spectrograph

    Science.gov (United States)

    Groff, Tyler D.; Kasdin, N. J.; Limbach, Mary A.; Galvin, Michael; Carr, Michael A.; Knapp, Gillian; Brandt, Timothy; Loomis, Craig; Jarosik, Norm; Mede, Kyle; McElwain, Michael W.; Janson, Markus; Guyon, Olivier; Jovanovic, Nemanja; Takato, Naruhisa; Martinache, Frantz; Hayashi, Masahiko

    2014-07-01

    Princeton University is building the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), an integral field spectrograph (IFS) for the Subaru telescope. CHARIS is funded by the National Astronomical Observatory of Japan and is designed to take high contrast spectra of brown dwarfs and hot Jovian planets in the coronagraphic image provided by the Coronagraphic Extreme Adaptive Optics (SCExAO) and the AO188 adaptive optics systems. The project is now in the build and test phase at Princeton University. Once laboratory testing has been completed CHARIS will be integrated with SCExAO and AO188 in the winter of 2016. CHARIS has a high-resolution characterization mode in J, H, and K bands. The average spectral resolution in J, H, and K bands are R82, R68, and R82 respectively, the uniformity of which is a direct result of a new high index material, L-BBH2. CHARIS also has a second low-resolution imaging mode that spans J,H, and K bands with an average spectral resolution of R19, a feature unique to this instrument. The field of view in both imaging modes is 2.07x2.07 arcseconds. SCExAO+CHARIS will detect objects five orders of magnitude dimmer than their parent star down to an 80 milliarcsecond inner working angle. The primary challenge with exoplanet imaging is the presence of quasi-static speckles in the coronagraphic image. SCExAO has a wavefront control system to suppress these speckles and CHARIS will address their impact on spectral crosstalk through hardware design, which drives its optical and mechanical design. CHARIS constrains crosstalk to be below 1% for an adjacent source that is a full order of magnitude brighter than the neighboring spectra. Since CHARIS is on the Nasmyth platform, the optical alignment between the lenslet array and prism is highly stable. This improves the stability of the spectra and their orientation on the detector and results in greater stability in the wavelength solution for the data pipeline. This means less

  2. Design and Construction of VUES: The Vilnius University Echelle Spectrograph

    Science.gov (United States)

    Jurgenson, Colby; Fischer, Debra; McCracken, Tyler; Sawyer, David; Giguere, Matt; Szymkowiak, Andrew; Santoro, Fernando; Muller, Gary

    2016-03-01

    In February 2014, the Yale Exoplanet Laboratory was commissioned to design, build, and deliver a high resolution (R=60,000) spectrograph for the 1.65m telescope at the Molėtai Astronomical Observatory. The observatory is operated by the Institute of Theoretical Physics and Astronomy at Vilnius University. The Vilnius University Echelle Spectrograph (VUES) is a white-pupil design that is fed via an octagonal fiber from the telescope and has an operational bandpass from 400nm to 880nm. VUES incorporates a novel modular optomechanical design that allows for quick assembly and alignment on commercial optical tables. This approach allowed the spectrograph to be assembled and commissioned at Yale using lab optical tables and then reassembled at the observatory on a different optical table with excellent repeatability. The assembly and alignment process for the spectrograph was reduced to a few days, allowing the spectrograph to be completely disassembled for shipment to Lithuania, and then installed at the observatory during a 10-day period in June of 2015.

  3. Echelle spectrograph software design aid

    Science.gov (United States)

    Dantzler, A. A.

    1985-01-01

    A method for mapping, to first order, the spectrograms that result from echelle spectrographic systems is discussed. An in-depth description of the principles behind the method are given so that software may be generated. Such software is an invaluable echelle spectrograph design aid. Results from two applications are discussed.

  4. Compact low resolution spectrograph, an imaging and long slit spectrograph for robotic telescopes

    International Nuclear Information System (INIS)

    The COmpact LOw REsolution Spectrograph (COLORES) is a compact and lightweight (13 kg) f/8 imaging spectrograph designed for robotic telescopes, now installed and operating on the TELMA, a rapid-slewing 60 cm telescope of the BOOTES-2 observatory in Málaga (Spain). COLORES is a multi-mode instrument that enables the observer to seamlessly switch between low-dispersion spectroscopy and direct imaging modes during an observation. In this paper, we describe the instrument and its development, from the initial scientific requirements through the optical design process to final configuration with theoretical performance calculations. The mechanical and electronic design is described, methods of calibration are discussed and early laboratory and scientific results are shown

  5. A new fiber slit assembly for the FOCES spectrograph

    Science.gov (United States)

    Kellermann, Hanna; Grupp, Frank; Brucalassi, Anna; Lang-Bardl, Florian; Franik, Christian; Hopp, Ulrich; Bender, Ralf

    2015-09-01

    After successful operation at the Calar Alto telescope until 2009, and extensive lab tests at the Munich University Observatory the high resolution Échelle spectrograph FOCES (Fiber Optics Cassegrain Échelle Spectrograph) is now about to be reinstalled at the 2 m Wendelstein Observatory in the German Alps. For this new phase of operation FOCES will be equipped with new components that will improve time stability and wavelength calibration. With these modifications FOCES will meet the requirements for performing precision radial velocity measurements on a competitive level. One of the key features of the upgraded spectrograph is the new calibration system, which uses a laser frequency comb as reference light source. Another aspect is the possibility to perform simultaneous wavelength calibration, while recording science data. For this purpose a new 4-fiber slit has been developed, which opens up the possibility to feed light from different sources at the same time through the entrance slit of the spectrograph. We present a detailed characterization of this new device, based on the results of extensive lab tests performed at the Munich University Observatory.

  6. The Development of WIFIS: a Wide Integral Field Infrared Spectrograph

    CERN Document Server

    Sivanandam, Suresh; Moon, Dae-Sik; Ma, Ke; Millar-Blanchaer, Maxwell; Eikenberry, Stephen S; Chun, Moo-Young; Kim, Sang Chul; Raines, Steven N; Eisner, Joshua

    2012-01-01

    We present the current results from the development of a wide integral field infrared spectrograph (WIFIS). WIFIS offers an unprecedented combination of etendue and spectral resolving power for seeing-limited, integral field observations in the 0.9-1.8 um range and is most sensitive in the 0.9-1.35 um range. Its optical design consists of front-end re-imaging optics, an all-reflective image slicer-type, integral field unit (IFU) called FISICA, and a long-slit grating spectrograph back-end that is coupled with a HAWAII 2RG focal plane array. The full wavelength range is achieved by selecting between two different gratings. By virtue of its re-imaging optics, the spectrograph is quite versatile and can be used at multiple telescopes. The size of its field-of-view is unrivalled by other similar spectrographs, offering a 4.5" x 12" integral field at a 10-meter class telescope (or 20" x 50" at a 2.3-meter telescope). The use of WIFIS will be crucial in astronomical problems which require wide-field, two-dimensiona...

  7. Modelling the application of integrated photonic spectrographs to astronomy

    CERN Document Server

    Harris, R J

    2012-01-01

    One of the well-known problems of producing instruments for Extremely Large Telescopes is that their size (and hence cost) scales rapidly with telescope aperture. To try to break this relation alternative new technologies have been proposed, such as the use of the Integrated Photonic Spectrograph (IPS). Due to their diffraction limited nature the IPS is claimed to defeat the harsh scaling law applying to conventional instruments. The problem with astronomical applications is that unlike conventional photonics, they are not usually fed by diffraction limited sources. This means in order to retain throughput and spatial information the IPS will require multiple Arrayed Waveguide Gratings (AWGs) and a photonic lantern. We investigate the implications of these extra components on the size of the instrument. We also investigate the potential size advantage of using an IPS as opposed to conventional monolithic optics. To do this, we have constructed toy models of IPS and conventional image sliced spectrographs to c...

  8. Biographical encyclopedia of astronomers

    CERN Document Server

    Trimble, Virginia; Williams, Thomas; Bracher, Katherine; Jarrell, Richard; Marché, Jordan; Palmeri, JoAnn; Green, Daniel

    2014-01-01

    The Biographical Encyclopedia of Astronomers is a unique and valuable resource for historians and astronomers alike. It includes approx. 1850 biographical sketches on astronomers from antiquity to modern times. It is the collective work of 430 authors edited by an editorial board of 8 historians and astronomers. This reference provides biographical information on astronomers and cosmologists by utilizing contemporary historical scholarship. The fully corrected and updated second edition adds approximately 300 biographical sketches. Based on ongoing research and feedback from the community, the new entries will fill gaps and provide expansions. In addition, greater emphasis on Russo phone astronomers and radio astronomers is given. Individual entries vary from 100 to 1500 words, including the likes of the super luminaries such as Newton and Einstein, as well as lesser-known astronomers like Galileo's acolyte, Mario Guiducci.

  9. LOTUS: A low cost, ultraviolet spectrograph

    CERN Document Server

    Steele, I A; Jermak, H E; Barnsley, R M; Bates, S D; Clay, N R; Fitzsimmons, A; Jehin, E; Jones, G; Mottram, C J; Smith, R J; Snodgrass, C; de Val-Borro, M

    2016-01-01

    We describe the design, construction and commissioning of LOTUS; a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5x95 arcsec) and wide (5x25 arcsec) options that are optimized for spectral resolution and flux calibration respectively. On sky testing shows a wavelength range of 3200-6300 Angstroms with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependant spectral resolution of R=225-430. By repeated observations of the symbiotic emission line star AG Peg we demonstrate the wavelength stability of the system is less than 2 Angstroms rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its ...

  10. Atmospheric Scintillation in Astronomical Photometry

    CERN Document Server

    Osborn, J; Dhillon, V S; Wilson, R W

    2015-01-01

    Scintillation noise due to the Earth's turbulent atmosphere can be a dominant noise source in high-precision astronomical photometry when observing bright targets from the ground. Here we describe the phenomenon of scintillation from its physical origins to its effect on photometry. We show that Young's (1967) scintillation-noise approximation used by many astronomers tends to underestimate the median scintillation noise at several major observatories around the world. We show that using median atmospheric optical turbulence profiles, which are now available for most sites, provides a better estimate of the expected scintillation noise and that real-time turbulence profiles can be used to precisely characterise the scintillation noise component of contemporaneous photometric measurements. This will enable a better understanding and calibration of photometric noise sources and the effectiveness of scintillation correction techniques. We also provide new equations for calculating scintillation noise, including ...

  11. Polarimetric calibration of large mirrors

    CERN Document Server

    Ariste, A Lopez

    2015-01-01

    Aims: To propose a method for the polarimetric calibration of large astronomical mirrors that does not require use of special optical devices nor knowledge of the exact polarization properties of the calibration target. Methods: We study the symmetries of the Mueller matrix of mirrors to exploit them for polarimetric calibration under the assumptions that only the orientation of the linear polarization plane of the calibration target is known with certainty. Results: A method is proposed to calibrate the polarization effects of single astronomical mirrors by the observation of calibration targets with known orientation of the linear polarization. We study the uncertainties of the method and the signal-to-noise ratios required for an acceptable calibration. We list astronomical targets ready for the method. We finally extend the method to the calibration of two or more mirrors, in particular to the case when they share the same incidence plane.

  12. Astrophotonics: a new era for astronomical instruments

    CERN Document Server

    Bland-Hawthorn, J

    2009-01-01

    Astrophotonics lies at the interface of astronomy and photonics. This burgeoning field -- now formally recognized by the optics community -- has emerged over the past decade in response to the increasing demands of astronomical instrumentation. Early successes include: (i) planar waveguides to combine signals from widely spaced telescopes in stellar interferometry; (ii) frequency combs for ultra-high precision spectroscopy to detect planets around nearby stars; (iii) ultra-broadband fibre Bragg gratings to suppress unwanted background; (iv) photonic lanterns that allow single-mode behaviour within a multimode fibre; (v) planar waveguides to miniaturize astronomical spectrographs; (vi) large mode area fibres to generate artificial stars in the upper atmosphere for adaptive optics correction; (vii) liquid crystal polymers in optical vortex coronographs and adaptive optics systems. Astrophotonics, a field that has already created new photonic capabilities, is now extending its reach down to the Rayleigh scatteri...

  13. Radioastronomy at the National Astronomical Observatory of Colombia

    Science.gov (United States)

    Guevara Gómez, J. C.; Calvo-Mozo, B.; Martinez Oliveros, J. C.

    2015-12-01

    Colombia is located in the northern tip of South America close to the amazon rain forest. This makes astronomical observations in the visible range very challenging, as cloud coverage is relatively high. Hence, radio astronomy becomes a natural and good choice. We present the design, characterization and first results of the Observatorio Astronomico Nacional solar radio spectrograph. This instrument is a Log-Periodic Dipole Array Antenna (LPDA) working between 100 MHz and 1 GHz optimized for solar observations. The radio spectrograph is a working prototype for a more ambitious solar radio interferometer, that will be the first instrument of this kind in Colombia.

  14. KIDSpec: an MKID based medium resolution integral field spectrograph

    Science.gov (United States)

    O'Brien, Kieran; Thatte, Niranjan; Mazin, Benjamin

    2014-07-01

    We present a novel concept for a highly sensitive, medium spectral resolution optical through near-IR spectrograph. KIDSpec, the Kinetic Inductance Detector Spectrograph, uses the intrinsic energy resolving capability of an array of optical/IR-sensitive MKIDs to distinguish multiple orders from a low line-density (echelle) grating. MKID arrays have a wide bandpass (0.1-2.5um) and good quantum efficiency, making them strong candidates for replacing CCDs in many astronomical instruments. By acting as an `order resolver', the MKID array replaces the cross-disperser in an echelle spectrograph. This greatly simplifies the optical layout of the spectrograph and enables longer slits than are possible with cross-dispersed instruments. KIDSpec would have similar capabilities to ESO's X-shooter instrument. It would provide an R=4000-10,000 spectrum covering the entire optical and near-IR spectral range. In addition to a `long-slit' mode, the IFU would provide a small (~50 spaxel) field-of-view for spatially resolved sources. In addition, the photon-counting operation of MKIDs and their photon-energy resolving ability enable a read-noise free spectrum with perfect cosmic ray removal. The spectral resolution would be sufficient to remove the bright night-sky lines without the additional pixel noise, making the instrument more sensitive than an equivalent semiconductor-based instrument. KIDSpec would enhance many existing high-profile science cases, including transient (GRB, SNe, etc.) follow-up, redshift determination of faint objects and transit spectroscopy of exoplanets. In addition it will enable unique science cases, such as dynamical mass estimates of the compact objects in ultra-compact binaries.

  15. Prime Focus Spectrograph - Subaru's future -

    CERN Document Server

    Sugai, Hajime; Takato, Naruhisa; Tamura, Naoyuki; Shimono, Atsushi; Ohyama, Youichi; Ueda, Akitoshi; Ling, Hung-Hsu; de Arruda, Marcio Vital; Barkhouser, Robert H; Bennett, Charles L; Bickerton, Steve; Braun, David F; Bruno, Robin J; Carr, Michael A; Oliveira, João Batista de Carvalho; Chang, Yin-Chang; Chen, Hsin-Yo; Dekany, Richard G; Dominici, Tania Pereira; Ellis, Richard S; Fisher, Charles D; Gunn, James E; Heckman, Timothy M; Ho, Paul T P; Hu, Yen-Shan; Jaquet, Marc; Karr, Jennifer; Kimura, Masahiko; Fèvre, Olivier Le; Mignant, David Le; Loomis, Craig; Lupton, Robert H; Madec, Fabrice; Marrara, Lucas Souza; Martin, Laurent; Murayama, Hitoshi; de Oliveira, Antonio Cesar; de Oliveira, Claudia Mendes; de Oliveira, Ligia Souza; Orndorff, Joe D; Vilaça, Rodrigo de Paiva; Macanhan, Vanessa Bawden de Paula; Prieto, Eric; Santos, Jesulino Bispo dos; Seiffert, Michael D; Smee, Stephen A; Smith, Roger M; Sodré, Laerte; Spergel, David N; Surace, Christian; Vives, Sebastien; Wang, Shiang-Yu; Yan, Chi-Hung

    2012-01-01

    The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution. Taking advantage of Subaru's wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a wide-field metrology camera. Fibers then carry l...

  16. Auto Adjusting Astronomical Telescope

    Directory of Open Access Journals (Sweden)

    Rohit R. Ghalsasi

    2014-04-01

    Full Text Available Astronomical telescope is powerful and basic tool for star or celestial observation. Here we proposed integrated system using Raspberry Pi for auto adjusting astronomical telescope. This integrated circuit helps to control stellar monitoring, stellar targeting, and tracking functions of telescope. Astro compass gives the direction of the celestial objects.

  17. Science case and requirements for the MOSAIC concept for a multi-object spectrograph for the European Extremely Large Telescope

    NARCIS (Netherlands)

    Evans, C. J.; Puech, M.; Barbuy, B.; Bonifacio, P.; Cuby, J.-G.; Guenther, E.; Hammer, F.; Jagourel, P.; Kaper, L.; Morris, S. L.; Afonso, J.; Amram, P.; Aussel, H.; Basden, A.; Bastian, N.; Battaglia, G.; Biller, B.; Bouché, N.; Caffau, E.; Charlot, S.; Clénet, Y.; Combes, F.; Conselice, C.; Contini, T.; Dalton, G.; Davies, B.; Disseau, K.; Dunlop, J.; Fiore, F.; Flores, H.; Fusco, T.; Gadotti, D.; Gallazzi, A.; Giallongo, E.; Gonçalves, T.; Gratadour, D.; Hill, V.; Huertas-Company, M.; Ibata, R.; Larsen, S.; Le Fèvre, O.; Lemasle, B.; Maraston, C.; Mei, S.; Mellier, Y.; Östlin, G.; Paumard, T.; Pello, R.; Pentericci, L.; Petitjean, P.; Roth, M.; Rouan, D.; Schaerer, D.; Telles, E.; Trager, S.; Welikala, N.; Zibetti, S.; Ziegler, B.

    2014-01-01

    Over the past 18 months we have revisited the science requirements for a multi-object spectrograph (MOS) for the European Extremely Large Telescope (E-ELT). These efforts span the full range of E-ELT science and include input from a broad cross-section of astronomers across the ESO partner countries

  18. V.M. Slipher and the Development of the Nebular Spectrograph

    CERN Document Server

    Thompson, Laird A

    2013-01-01

    Vesto Melvin Slipher was the first astronomer to clearly define the factors that determine the "speed" of a nebular spectrograph. This brief historical summary recounts the way these ideas developed and how Slipher's early work on galaxy Doppler shifts was so quickly extended in the 1930's when Milton Humason and Edwin Hubble at Mt. Wilson Observatory began to push the velocity-distance relationship to such a depth that no one could doubt its cosmological significance.

  19. Astronomical Video Suites

    Science.gov (United States)

    Francisco Salgado, Jose

    2010-01-01

    Astronomer and visual artist Jose Francisco Salgado has directed two astronomical video suites to accompany live performances of classical music works. The suites feature awe-inspiring images, historical illustrations, and visualizations produced by NASA, ESA, and the Adler Planetarium. By the end of 2009, his video suites Gustav Holst's The Planets and Astronomical Pictures at an Exhibition will have been presented more than 40 times in over 10 countries. Lately Salgado, an avid photographer, has been experimenting with high dynamic range imaging, time-lapse, infrared, and fisheye photography, as well as with stereoscopic photography and video to enhance his multimedia works.

  20. HERMES: a high-resolution fibre-fed spectrograph for the Mercator telescope

    CERN Document Server

    Raskin, Gert; Hensberge, Herman; Jorissen, Alain; Lehmann, Holger; Waelkens, Christoffel; Avila, Gerardo; De Cuyper, Jean-Pierre; Degroote, Pieter; Dubosson, Rene; Dumortier, Louis; Fremat, Yves; Laux, Uwe; Michaud, Bernard; Morren, Johan; Padilla, Jesus Perez; Pessemier, Wim; Prins, Saskia; Smolders, Kristof; Van Eck, Sophie; Winkler, Johannes

    2010-01-01

    The HERMES high-resolution spectrograph project aims at exploiting the specific potential of small but flexible telescopes in observational astrophysics. The optimised optical design of the spectrograph is based on the well-proven concept of white-pupil beam folding for high-resolution spectroscopy. In this contribution we present the complete project, including the spectrograph design and procurement details, the telescope adaptor and calibration unit, the detector system, as well as the optimised data-reduction pipeline. We present a detailed performance analysis to show that the spectrograph performs as specified both in optical quality and in total efficiency. With a spectral resolution of 85000 (63000 for the low-resolution fibre), a spectral coverage from 377 to 900nm in a single exposure and a peak efficiency of 28%, HERMES proves to be an ideal instrument for building up time series of high-quality data of variable (stellar) phenomena.

  1. On the Instrument Profile of Slit Spectrographs

    OpenAIRE

    Casini, R.; de Wijn, A.G.

    2014-01-01

    We derive an analytic expression for the instrument profile of a slit spectrograph, also known as the line spread function. While this problem is not new, our treatment relies on the operatorial approach to the description of diffractive optical systems, which provides a general framework for the analysis of the performance of slit spectrographs under different illumination conditions. Based on our results, we propose an approximation to the spectral resolution of slit spectrographs, taking i...

  2. First Light results from PARAS: The PRL Echelle Spectrograph

    CERN Document Server

    Chakraborty, Abhijit; Roy, Arpita; Pathan, Fazalahmed M; Shah, Vishal; Richardson, Eric H; Ubale, Girish; Shah, Rajesh

    2010-01-01

    We present the first light commissioning results from the Physical Research Laboratory (PRL) optical fiber-fed high resolution cross-dispersed Echelle Spectrograph. It is capable of a single- shot spectral coverage of 3700A to 8600A at R ~ 63,000 and is under very stable conditions of temperature (0.04{\\deg}C at 23{\\deg}C). In the very near future pressure control will also be achieved by enclosing the entire spectrograph in a low-pressure vacuum chamber (~0.01mbar). It is attached to a 1.2m telescope using two 50micron core optical fibers (one for the star and another for simultaneous Th-Ar spectral calibration). The 1.2m telescope is located at Mt. Abu, India, and we are guaranteed about 80 to 100 nights a year for observations with the spectrograph. The instrument will be ultimately used for radial-velocity searches of exoplanets around 1000 dwarf stars, brighter than 10th magnitude, for the next 5 years with a precision of 3 to 5m/s using the simultaneous Th-Ar spectral lamp reference technique. The spect...

  3. The infrared imaging spectrograph (IRIS) for TMT: sensitivities and simulations

    CERN Document Server

    Wright, Shelley A; Larkin, James E; Moore, Anna M; Crampton, David; Simard, Luc

    2010-01-01

    We present sensitivity estimates for point and resolved astronomical sources for the current design of the InfraRed Imaging Spectrograph (IRIS) on the future Thirty Meter Telescope (TMT). IRIS, with TMT's adaptive optics system, will achieve unprecedented point source sensitivities in the near-infrared (0.84 - 2.45 {\\mu}m) when compared to systems on current 8-10m ground based telescopes. The IRIS imager, in 5 hours of total integration, will be able to perform a few percent photometry on 26 - 29 magnitude (AB) point sources in the near-infrared broadband filters (Z, Y, J, H, K). The integral field spectrograph, with a range of scales and filters, will achieve good signal-to-noise on 22 - 26 magnitude (AB) point sources with a spectral resolution of R=4,000 in 5 hours of total integration time. We also present simulated 3D IRIS data of resolved high-redshift star forming galaxies (1 < z < 5), illustrating the extraordinary potential of this instrument to probe the dynamics, assembly, and chemical abunda...

  4. Field Raman spectrograph for environmental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Haas, J.W. III; Forney, R.W.; Carrabba, M.M. [EIC Labs, Norwood, MA (United States)] [and others

    1995-10-01

    This project entails the development of a compact raman spectrograph for field screening and monitoring of a wide variety of wastes, pollutants, and corrosion products in tanks, and environmental materials. The design of a fiber optic probe for use with the spectrograph is also discussed.

  5. High-resolving mass spectrographs and spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Wollnik, Hermann, E-mail: hwollnik@gmail.com [New Mexico State University, Department of Chemistry & Biochemistry (United States)

    2015-11-15

    Discussed are different types of high resolving mass spectrographs and spectrometers. In detail outlined are (1) magnetic and electric sector field mass spectrographs, which are the oldest systems, (2) Penning Trap mass spectrographs and spectrometers, which have achieved very high mass-resolving powers, but are technically demanding (3) time-of-flight mass spectrographs using high energy ions passing through accelerator rings, which have also achieved very high mass-resolving powers and are equally technically demanding, (4) linear time-of-flight mass spectrographs, which have become the most versatile mass analyzers for low energy ions, while the even higher performing multi-pass systems have only started to be used, (5) orbitraps, which also have achieved remarkably high mass-resolving powers for low energy ions.

  6. Alternative Astronomical FITS imaging

    CERN Document Server

    Varsaki, Eleni E; Fotopoulos, Vassilis; Skodras, Athanassios N

    2012-01-01

    Astronomical radio maps are presented mainly in FITS format. Astronomical Image Processing Software (AIPS) uses a set of tables attached to the output map to include all sorts of information concerning the production of the image. However this information together with information on the flux and noise of the map is lost as soon as the image of the radio source in fits or other format is extracted from AIPS. This information would have been valuable to another astronomer who just uses NED, for example, to download the map. In the current work, we show a method of data hiding inside the radio map, which can be preserved under transformations, even for example while the format of the map is changed from fits to other lossless available image formats.

  7. Atlas of Astronomical Discoveries

    CERN Document Server

    Schilling, Govert

    2011-01-01

    Four hundred years ago in Middelburg, in the Netherlands, the telescope was invented. The invention unleashed a revolution in the exploration of the universe. Galileo Galilei discovered mountains on the Moon, spots on the Sun, and moons around Jupiter. Christiaan Huygens saw details on Mars and rings around Saturn. William Herschel discovered a new planet and mapped binary stars and nebulae. Other astronomers determined the distances to stars, unraveled the structure of the Milky Way, and discovered the expansion of the universe. And, as telescopes became bigger and more powerful, astronomers delved deeper into the mysteries of the cosmos. In his Atlas of Astronomical Discoveries, astronomy journalist Govert Schilling tells the story of 400 years of telescopic astronomy. He looks at the 100 most important discoveries since the invention of the telescope. In his direct and accessible style, the author takes his readers on an exciting journey encompassing the highlights of four centuries of astronomy. Spectacul...

  8. Astrobiology: An Astronomer's Perspective

    OpenAIRE

    Bergin, Edwin A.

    2013-01-01

    In this review we explore aspects of the field of astrobiology from an astronomical viewpoint. We therefore focus on the origin of life in the context of planetary formation, with additional emphasis on tracing the most abundant volatile elements, C, H, O, and N that are used by life on Earth. We first explore the history of life on our planet and outline the current state of our knowledge regarding the delivery of the C, H, O, N elements to the Earth. We then discuss how astronomers track th...

  9. On the Instrument Profile of Slit Spectrographs

    CERN Document Server

    Casini, R

    2014-01-01

    We derive an analytic expression for the instrument profile of a slit spectrograph, also known as the line spread function. While this problem is not new, our treatment relies on the operatorial approach to the description of diffractive optical systems, which provides a general framework for the analysis of the performance of slit spectrographs under different illumination conditions. Based on our results, we propose an approximation to the spectral resolution of slit spectrographs, taking into account diffraction effects and sampling by the detector, which improves upon the often adopted approximation based on the root-sumsquare of the individual contributions from the slit, the grating, and the detector pixel.

  10. Astronomical Data in Undergraduate courses

    Science.gov (United States)

    Clarkson, William I.; Swift, Carrie; Hughes, Kelli; Burke, Christopher J. F.; Burgess, Colin C.; Elrod, Aunna V.; Howard, Brittany; Stahl, Lucas; Matzke, David; Bord, Donald J.

    2016-06-01

    We present status and plans for our ongoing efforts to develop data analysis and problem-solving skills through Undergraduate Astronomy instruction. While our initiatives were developed with UM-Dearborn’s student body primarily in mind, they should be applicable for a wide range of institution and of student demographics. We focus here on two strands of our effort.Firstly, students in our Introductory Astronomy (ASTR 130) general-education course now perform several “Data Investigations”, in which they interrogate the Hubble Legacy Archive to illustrate important course concepts. This was motivated in part by the realization that typical public data archives now include tools to interrogate the observations that are sufficiently accessible that introductory astronomy students can use them to perform real science, albeit mostly at a descriptive level. We are continuing to refine these investigations, and, most importantly, to critically assess their effectiveness in terms of the student learning outcomes we wish to achieve. This work is supported by grant HST-EO-13758, provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.Secondly, at the advanced-undergraduate level, students taking courses in our Astronomy minor are encouraged to gain early experience in techniques of astronomical observation and analysis that are used by professionals. We present two example projects from the Fall 2015 iteration of our upper-division course ASTR330 (The Cosmic Distance Ladder), one involving Solar System measurements, the second producing calibrated aperture photometry. For both projects students conducted, analysed, and interpreted observations using our 0.4m campus telescope, and used many of the same analysis tools as professional astronomers. This work is supported partly from a Research Initiation and Seed grant from the

  11. The On-Orbit Performance of the Space Telescope Imaging Spectrograph

    Science.gov (United States)

    Kimble, R. A.; Woodgate, B. E.; Bowers, C. W.; Kraemer, S. B.; Kaiser, M. E.; Gull, T. R.; Heap, S. R.; Danks, A. C.; Boggess, A.; Green, R. F.; Hutchings, J. B.; Jenkins, E. B.; Joseph, C. L.; Linsky, J. L.; Maran, S. P.; Moos, H. W.; Roesler, F.; Timothy, J. G.; Weistrop, D. E.; Grady, J. F.; Loiacono, J. J.; Brown, L. W.; Brumfield, M. D.; Content, D. A.; Feinberg, L. D.; Isaacs, M. N.; Krebs, C. A.; Krueger, V. L.; Melcher, R. W.; Rebar, F. J.; Vitagliano, H. D.; Yagelowich, J. J.; Meyer, W. W.; Hood, D. F.; Argabright, V. S.; Becker, S. I.; Bottema, M.; Breyer, R. R.; Bybee, R. L.; Christon, P. R.; Delamere, A. W.; Dorn, D. A.; Downey, S.; Driggers, P. A.; Ebbets, D. C.; Gallegos, J. S.; Garner, H.; Hetlinger, J. C.; Lettieri, R. L.; Ludtke, C. W.; Michika, D.; Nyquist, R.; Rose, D. M.; Stocker, R. B.; Sullivan, J. F.; Van Houten, C. N.; Woodruff, R. A.; Baum, S. A.; Hartig, G. F.; Balzano, V.; Biagetti, C.; Blades, J. C.; Bohlin, R. C.; Clampin, M.; Doxsey, R.; Ferguson, H. C.; Goudfrooij, P.; Hulbert, S. J.; Kutina, R.; McGrath, M.; Lindler, D. J.; Beck, T. L.; Feggans, J. K.; Plait, P. C.; Sandoval, J. L.; Hill, R. S.; Collins, N. R.; Cornett, R. H.; Fowler, W. B.; Hill, R. J.; Landsman, W. B.; Malumuth, E. M.; Standley, C.; Blouke, M.; Grusczak, A.; Reed, R.; Robinson, R. D.; Valenti, J. A.; Wolfe, T.

    1998-01-01

    The Space Telescope Imaging Spectrograph (STIS) was successfully installed into the Hubble Space Telescope (HST) in 1997 February, during the second HST servicing mission, STS-82. STIS is a versatile spectrograph, covering the 115-1000 nm wavelength range in a variety of spectroscopic and imaging modes that take advantage of the angular resolution, unobstructed wavelength coverage, and dark sky offered by the HST. In the months since launch, a number of performance tests and calibrations have been carried out and are continuing. These tests demonstrate that the instrument is performing very well. We present here a synopsis of the results to date.

  12. NIR Camera/spectrograph: TEQUILA

    Science.gov (United States)

    Ruiz, E.; Sohn, E.; Cruz-Gonzalez, I.; Salas, L.; Parraga, A.; Torres, R.; Perez, M.; Cobos, F.; Tejada, C.; Iriarte, A.

    1998-11-01

    We describe the configuration and operation modes of the IR camera/spectrograph called TEQUILA, based on a 1024X1024 HgCdTe FPA (HAWAII). The optical system will allow three possible modes of operation: direct imaging, low and medium resolution spectroscopy and polarimetry. The basic system is being designed to consist of the following: 1) A LN$_2$ dewar that allocates the FPA together with the preamplifiers and a 24 filter position cylinder. 2) Control and readout electronics based on DSP modules linked to a workstation through fiber optics. 3) An optomechanical assembly cooled to -30oC that provides an efficient operation of the instrument in its various modes. 4) A control module for the moving parts of the instrument. The opto-mechanical assembly will have the necessary provisions to install a scanning Fabry-Perot interferometer and an adaptive optics correction system. The final image acquisition and control of the whole instrument is carried out in a workstation to provide the observer with a friendly environment. The system will operate at the 2.1 m telescope at the Observatorio Astronomico Nacional in San Pedro Martir, B.C. (Mexico), and is intended to be a first-light instrument for the new 7.8 m Mexican Infrared-Optical Telescope (TIM).

  13. Astronomers as Software Developers

    Science.gov (United States)

    Pildis, Rachel A.

    2016-01-01

    Astronomers know that their research requires writing, adapting, and documenting computer software. Furthermore, they often have to learn new computer languages and figure out how existing programs work without much documentation or guidance and with extreme time pressure. These are all skills that can lead to a software development job, but recruiters and employers probably won't know that. I will discuss all the highly useful experience that astronomers may not know that they already have, and how to explain that knowledge to others when looking for non-academic software positions. I will also talk about some of the pitfalls I have run into while interviewing for jobs and working as a developer, and encourage you to embrace the curiosity employers might have about your non-standard background.

  14. Studying focal ratio degradation of optical fibers for Subaru Prime Focus Spectrograph

    CERN Document Server

    Santos, Jesulino Bispo dos; Gunn, James; de Oliveira, Ligia Souza; de Arruda, Marcio Vital; Castilho, Bruno; Gneiding, Clemens Darvin; Ribeiro, Flavio Felipe; Murray, Graham; Reiley, Daniel J; Junior, Laerte Sodré; de Oliveira, Claudia Mendes

    2014-01-01

    Focal Ration Degradation (FRD) is a change in light angular distribution caused by fiber optics. FRD is important to fiber-fed, spectroscopic astronomical systems because it can cause loss of signal, degradation in spectral resolution, or increased complexity in spectrograph design. Laborat\\'orio Nacional de Astrof\\'isica (LNA) has developed a system that can accurately and precisely measures FRD, using an absolute method that can also measure fiber throughput. This paper describes the metrology system and shows measurements of Polymicro fiber FBP129168190, FBP127165190 and Fujikura fiber 128170190. Although the FRD of the two fibers are low and similar to one another, it is very important to know the exact characteristics of these fibers since both will be used in the construction of FOCCoS (Fiber Optical Cable and Connectors System) for PFS (Prime Focus Spectrograph) to be installed at the Subaru telescope.

  15. MEGARA: a new generation optical spectrograph for GTC

    Science.gov (United States)

    Gil de Paz, A.; Gallego, J.; Carrasco, E.; Iglesias-Páramo, J.; Cedazo, R.; Vílchez, J. M.; García-Vargas, M. L.; Arrillaga, X.; Carrera, M. A.; Castillo-Morales, A.; Castillo-Domínguez, E.; Eliche-Moral, M. C.; Ferrusca, D.; González-Guardia, E.; Lefort, B.; Maldonado, M.; Marino, R. A.; Martínez-Delgado, I.; Morales Durán, I.; Mujica, E.; Páez, G.; Pascual, S.; Pérez-Calpena, A.; Sánchez-Penim, A.; Sánchez-Blanco, E.; Tulloch, S.; Velázquez, M.; Zamorano, J.; Aguerri, A. L.; Barrado y Naváscues, D.; Bertone, E.; Cardiel, N.; Cava, A.; Cenarro, J.; Chávez, M.; García, M.; Guichard, J.; Gúzman, R.; Herrero, A.; Huélamo, N.; Hughes, D.; Jiménez-Vicente, J.; Kehrig, C.; Márquez, I.; Masegosa, J.; Mayya, Y. D.; Méndez-Abreu, J.; Mollá, M.; Muñoz-Tuñón, C.; Peimbert, M.; Pérez-González, P. G.; Pérez Montero, E.; Rodríguez, M.; Rodríguez-Espinosa, J. M.; Rodríguez-Merino, L.; Rosa-González, D.; Sánchez-Almeida, J.; Sánchez Contreras, C.; Sánchez-Blázquez, P.; Sánchez Moreno, F. M.; Sánchez, S. F.; Sarajedini, A.; Serena, F.; Silich, S.; Simón-Díaz, S.; Tenorio-Tagle, G.; Terlevich, E.; Terlevich, R.; Torres-Peimbert, S.; Trujillo, I.; Tsamis, Y.; Vega, O.; Villar, V.

    2014-07-01

    MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4m telescope in La Palma. MEGARA offers two IFU fiber bundles, one covering 12.5x11.3 arcsec2 with a spaxel size of 0.62 arcsec (Large Compact Bundle; LCB) and another one covering 8.5x6.7 arcsec2 with a spaxel size of 0.42 arcsec (Small Compact Bundle; SCB). The MEGARA MOS mode will allow observing up to 100 objects in a region of 3.5x3.5 arcmin2 around the two IFU bundles. Both the LCB IFU and MOS capabilities of MEGARA will provide intermediate-to-high spectral resolutions (RFWHM~6,000, 12,000 and 18,700, respectively for the low-, mid- and high-resolution Volume Phase Holographic gratings) in the range 3650-9700ÅÅ. These values become RFWHM~7,000, 13,500, and 21,500 when the SCB is used. A mechanism placed at the pseudo-slit position allows exchanging the three observing modes and also acts as focusing mechanism. The spectrograph is a collimator-camera system that has a total of 11 VPHs simultaneously available (out of the 18 VPHs designed and being built) that are placed in the pupil by means of a wheel and an insertion mechanism. The custom-made cryostat hosts an E2V231-84 4kx4k CCD. The UCM (Spain) leads the MEGARA Consortium that also includes INAOE (Mexico), IAA-CSIC (Spain), and UPM (Spain). MEGARA is being developed under a contract between GRANTECAN and UCM. The detailed design, construction and AIV phases are now funded and the instrument should be delivered to GTC before the end of 2016.

  16. Progress on the Gemini High-Resolution Optical SpecTrograph (GHOST) design

    Science.gov (United States)

    Ireland, Michael; Anthony, Andre; Burley, Greg; Chisholm, Eric; Churilov, Vladimir; Dunn, Jennifer; Frost, Gabriella; Lawrence, Jon; Loop, David; McGregor, Peter; Martell, Sarah; McConnachie, Alan; McDermid, Richard M.; Pazder, John; Reshetov, Vlad; Robertson, J. G.; Sheinis, Andrew; Tims, Julia; Young, Peter; Zhelem, Ross

    2014-07-01

    The Gemini High-Resolution Optical SpecTrograph (GHOST) is the newest instrument being developed for the Gemini telescopes, in a collaboration between the Australian Astronomical Observatory (AAO), the NRC - Herzberg in Canada and the Australian National University (ANU). We describe the process of design optimisation that utilizes the unique strengths of the new partner, NRC - Herzberg, the design and need for the slit viewing camera system, and we describe a simplification for the lenslet-based slit reformatting. Finally, we out- line the updated project plan, and describe the unique scientific role this instrument will have in an international context, from exoplanets through to the distant Universe.

  17. A spectrograph instrument concept for the Prime Focus Spectrograph (PFS) on Subaru Telescope

    CERN Document Server

    Vives, Sébastien; Madec, Fabrice; Jaquet, Marc; Prieto, Eric; Martin, Laurent; Fèvre, Olivier Le; Gunn, James; Carr, Michael; Smee, Stephen; Barkhouser, Robert; Sugai, Hajime; Tamura, Naoyuki

    2012-01-01

    We describe the conceptual design of the spectrograph opto-mechanical concept for the SuMIRe Prime Focus Spectrograph (PFS) being developed for the SUBARU telescope. The SuMIRe PFS will consist of four identical spectrographs, each receiving 600 fibers from a 2400 fiber robotic positioner at the prime focus. Each spectrograph will have three channels covering in total, a wavelength range from 380 nm to 1300 nm. The requirements for the instrument are summarized in Section 1. We present the optical design and the optical performance and analysis in Section 2. Section 3 introduces the mechanical design, its requirements and the proposed concepts. Finally, the AIT phases for the Spectrograph System are described in Section 5.

  18. The Biographical Encyclopedia of Astronomers

    CERN Document Server

    Hockey, Thomas; Williams, Thomas R; Bracher, Katherine; Jarrell, Richard A; Marché, Jordan D; Ragep, F. Jamil; Palmeri, JoAnn; Bolt, Marvin

    2007-01-01

    The Biographical Encyclopedia of Astronomers is a unique and valuable resource for historians and astronomers alike. The two volumes include approximately 1550 biographical sketches on astronomers from antiquity to modern times. It is the collective work of about 400 authors edited by an editorial board of 9 historians and astronomers, and provides additional details on the nature of an entry and some summary statistics on the content of entries. This new reference provides biographical information on astronomers and cosmologists by utilizing contemporary historical scholarship. Individual entries vary from 100 to 1500 words, including the likes of the superluminaries such as Newton and Einstein, as well as lesser-known astronomers like Galileo's acolyte, Mario Guiducci. A comprehensive contributor index helps researchers to identify the authors of important scientific topics and treatises.

  19. Really Bad Astronomers

    Science.gov (United States)

    Hockey, Thomas A.

    2009-01-01

    What happens when even Percival Lowell stops believing in your Mars observations? History can be troubling. This I learned while editing the Biographical Encyclopedia of Astronomers (Springer, 2007). There have been astronomers who do not fit our commonly held, and clung to, conceptual model: a sociological system that sifts out generally like-minded and sensible colleagues. I refer to those individuals who (for at least a time) successfully entered the mainstream profession, but now disturb our worldview that says prosperity as a scientist usually is achieved by a rational being holding certain common values. My List of Shame includes examples from each of the last four centuries. Not "crack pot” cosmologists, these were hard-working observers for whom the end justified the means. And they all got away with it. Each person I discuss was vetted by the professional establishment of the day. Yet you will learn how to be fired from a major observatory, banned from prominent journals. But only after damage to the science is done. Be afraid.

  20. Grigor Narekatsi's astronomical insights

    Science.gov (United States)

    Poghosyan, Samvel

    2015-07-01

    What stand out in the solid system of Gr. Narekatsi's naturalistic views are his astronomical insights on the material nature of light, its high speed and the Sun being composed of "material air". Especially surprising and fascinating are his views on stars and their clusters. What astronomers, including great Armenian academician V. Ambartsumian (scattering of stellar associations), would understand and prove with much difficulty thousand years later, Narekatsi predicted in the 10th century: "Stars appear and disappear untimely", "You who gather and scatter the speechless constellations, like a flock of sheep". Gr. Narekatsti's reformative views were manifested in all the spheres of the 10th century social life; he is a reformer of church life, great language constructor, innovator in literature and music, freethinker in philosophy and science. His ideology is the reflection of the 10th century Armenian Renaissance. During the 9th-10th centuries, great masses of Armenians, forced to migrate to the Balkans, took with them and spread reformative ideas. The forefather of the western science, which originated in the period of Reformation, is considered to be the great philosopher Nicholas of Cusa. The study of Gr. Narekatsti's logic and naturalistic views enables us to claim that Gr. Narekatsti is the great grandfather of European science.

  1. Professional Ethics for Astronomers

    Science.gov (United States)

    Marvel, K. B.

    2005-05-01

    There is a growing recognition that professional ethics is an important topic for all professional scientists, especially physical scientists. Situations at the National Laboratories have dramatically proven this point. Professional ethics is usually only considered important for the health sciences and the legal and medical professions. However, certain aspects of the day to day work of professional astronomers can be impacted by ethical issues. Examples include refereeing scientific papers, serving on grant panels or telescope allocation committees, submitting grant proposals, providing proper references in publications, proposals or talks and even writing recommendation letters for job candidates or serving on search committees. This session will feature several speakers on a variety of topics and provide time for questions and answers from the audience. Confirmed speakers include: Kate Kirby, Director Institute for Theoretical Atomic and Molecular Physics - Professional Ethics in the Physical Sciences: An Overview Rob Kennicutt, Astrophysical Journal Editor - Ethical Issues for Publishing Astronomers Peggy Fischer, Office of the NSF Inspector General - Professional Ethics from the NSF Inspector General's Point of View

  2. Performance estimates for spectrographs using photonic reformatters

    CERN Document Server

    Harris, Robert J; Lemke, Ulrike; MacLachlan, David G; Thomson, Robert R; Reffert, Sabine; Quirrenbach, Andreas

    2016-01-01

    Using a photonic reformatter to eliminate the effects of conventional modal noise could greatly improve the stability of a high resolution spectrograph. However the regimes where this advantage becomes clear are not yet defined. Here we will look at where modal noise becomes a problem in conventional high resolution spectroscopy and what impact photonic spectrographs could have. We will theoretically derive achievable radial velocity measurements to compare photonic instruments and conventional ones. We will discuss the theoretical and experimental investigations that will need to be undertaken to optimize and prove the photonic reformatting concept.

  3. Developing arrayed waveguide grating spectrographs for multi-object astronomical spectroscopy

    CERN Document Server

    Cvetojevic, Nick; Lawrence, Jon; Withford, Michael; Bland-Hawthorn, Joss

    2012-01-01

    With the aim of utilizing arrayed waveguide gratings for multi-object spectroscopy in the field of astronomy, we outline several ways in which standard telecommunications grade chips should be modified. In particular, by removing the parabolic-horn taper or multimode interference coupler, and injecting with an optical fiber directly, the resolving power was increased threefold from 2400 \\pm 200 (spectral resolution of 0.63 \\pm 0.2 nm) to 7000 \\pm 700 (0.22 \\pm 0.02 nm) while attaining a throughput of 77 \\pm 5%. More importantly, the removal of the taper enabled simultaneous off-axis injection from multiple fibers, significantly increasing the number of spectra that can be obtained at once (i.e. the observing efficiency). Here we report that ~ 12 fibers can be injected simultaneously within the free spectral range of our device, with a 20% reduction in resolving power for fibers placed at 0.8 mm off centre.

  4. Astronomical tides and earthquakes

    Science.gov (United States)

    Wu, Xiaoping; Mao, Wei; Huang, Yong

    2001-03-01

    A review on the studies of correlation between astronomical tides and earthquakes is given in three categories, including (1) earthquakes and the relative locations of the sun, the moon and the earth, (2) earthquakes and the periods and phases of tides and (3) earthquakes and the tidal stress. The first two categories mainly investigate whether or not there exist any dominant pattern of the relative locations of the sun, the moon and the earth during earthquakes, whether or not the occurrences of earthquakes are clustered in any special phase during a tidal period, whether or not there exists any tidal periodic phenomenon in seismic activities, By empasizing the tidal stress in seismic focus, the third category investigates the relationship between various seismic faults and the triggering effects of tidal stress, which reaches the crux of the issue. Possible reasons to various inconsistent investigation results by using various methods and samples are analyzed and further investigations are proposed.

  5. The SIMBAD astronomical database

    CERN Document Server

    Wenger, M; Egret, D; Dubois, P; Bonnarel, F; Borde, S; Genova, F; Jasniewicz, G; Laloe, S; Lesteven, S; Monier, R; Wenger, Marc; Ochsenbein, Francois; Egret, Daniel; Dubois, Pascal; Bonnarel, Francois; Borde, Suzanne; Genova, Francoise; Jasniewicz, Gerard; Laloe, Suzanne; Lesteven, Soizick; Monier, Richard

    2000-01-01

    Simbad is the reference database for identification and bibliography ofastronomical objects. It contains identifications, `basic data', bibliography,and selected observational measurements for several million astronomicalobjects. Simbad is developed and maintained by CDS, Strasbourg. Building thedatabase contents is achieved with the help of several contributing institutes.Scanning the bibliography is the result of the collaboration of CDS withbibliographers in Observatoire de Paris (DASGAL), Institut d'Astrophysique deParis, and Observatoire de Bordeaux. When selecting catalogues and tables forinclusion, priority is given to optimal multi-wavelength coverage of thedatabase, and to support of research developments linked to large projects. Inparallel, the systematic scanning of the bibliography reflects the diversityand general trends of astronomical research. A WWW interface to Simbad is available at: http://simbad.u-strasbg.fr/Simbad

  6. Single mode, extreme precision Doppler spectrographs

    CERN Document Server

    Schwab, Christian; Betters, Christopher H; Bland-Hawthorn, Joss; Mahadevan, Suvrath

    2012-01-01

    The 'holy grail' of exoplanet research today is the detection of an earth-like planet: a rocky planet in the habitable zone around a main-sequence star. Extremely precise Doppler spectroscopy is an indispensable tool to find and characterize earth-like planets; however, to find these planets around solar-type stars, we need nearly one order of magnitude better radial velocity (RV) precision than the best current spectrographs provide. Recent developments in astrophotonics (Bland-Hawthorn & Horton 2006, Bland-Hawthorn et al. 2010) and adaptive optics (AO) enable single mode fiber (SMF) fed, high resolution spectrographs, which can realize the next step in precision. SMF feeds have intrinsic advantages over multimode fiber or slit coupled spectrographs: The intensity distribution at the fiber exit is extremely stable, and as a result the line spread function of a well-designed spectrograph is fully decoupled from input coupling conditions, like guiding or seeing variations (Ihle et al. 2010). Modal noise, a...

  7. The Infrared Imaging Spectrograph (IRIS) for TMT: Volume phase holographic grating performance testing and discussion

    CERN Document Server

    Chen, Shaojie; Wright, Shelley A; Moore, Anna M; Larkin, James E; Maire, Jerome; Mieda, Etsuko; Simard, Luc

    2014-01-01

    Maximizing the grating efficiency is a key goal for the first light instrument IRIS (Infrared Imaging Spectrograph) currently being designed to sample the diffraction limit of the TMT (Thirty Meter Telescope). Volume Phase Holographic (VPH) gratings have been shown to offer extremely high efficiencies that approach 100% for high line frequencies (i.e., 600 to 6000l/mm), which has been applicable for astronomical optical spectrographs. However, VPH gratings have been less exploited in the near-infrared, particularly for gratings that have lower line frequencies. Given their potential to offer high throughputs and low scattered light, VPH gratings are being explored for IRIS as a potential dispersing element in the spectrograph. Our team has procured near-infrared gratings from two separate vendors. We have two gratings with the specifications needed for IRIS current design: 1.51-1.82{\\mu}m (H-band) to produce a spectral resolution of 4000 and 1.19- 1.37 {\\mu}m (J-band) to produce a spectral resolution of 8000....

  8. CCD Readout Electronics for the Subaru Prime Focus Spectrograph

    OpenAIRE

    Hope, Stephen C.; Gunn, James E.; Loomis, Craig P.; Fitzgerald, Roger E.; Peacock, Grant O.

    2014-01-01

    We present details of the design for the CCD readout electronics for the Subaru Telescope Prime Focus Spectrograph (PFS). The spectrograph is comprised of four identical spectrograph modules, each collecting roughly 600 spectra. The spectrograph modules provide simultaneous wavelength coverage over the entire band from 380 nm to 1260 nm through the use of three separate optical channels: blue, red, and near infrared (NIR). A camera in each channel images the multi-object spectra onto a 4k x 4...

  9. XEphem: Interactive Astronomical Ephemeris

    Science.gov (United States)

    Downey, Elwood Charles

    2011-12-01

    XEphem is a scientific-grade interactive astronomical ephemeris package for UNIX-like systems. Written in C, X11 and Motif, it is easily ported to systems. Among other things, XEphem: computes heliocentric, geocentric and topocentric information for all objects; has built-in support for all planets; the moons of Mars, Jupiter, Saturn, Uranus and Earth; central meridian longitude of Mars and Jupiter; Saturn's rings; and Jupiter's Great Red Spot; allows user-defined objects including stars, deepsky objects, asteroids, comets and Earth satellites; provides special efficient handling of large catalogs including Tycho, Hipparcos, GSC; displays data in configurable tabular formats in conjunction with several interactive graphical views; displays a night-at-a-glance 24 hour graphic showing when any selected objects are up; displays 3-D stereo Solar System views that are particularly well suited for visualizing comet trajectories; quickly finds all close pairs of objects in the sky; and sorts and prints all catalogs with very flexible criteria for creating custom observing lists. Its capabilities are listed more fully in the user manual introduction.

  10. Applications of Integrated Photonic Spectrographs in Astronomy

    CERN Document Server

    Harris, Robert James

    2012-01-01

    One of the problems of producing instruments for Extremely Large Telescopes is that their size (and hence cost) scales rapidly with telescope aperture. To try to break this relation alternative new technologies have been proposed, such as the use of the Integrated Photonic Spectrograph (IPS). Due to their diffraction-limited nature the IPS is claimed to defeat the harsh scaling law applying to conventional instruments. In contrast to photonic applications, devices for astronomy are not usually used at the diffraction limit. Therefore to retain throughput and spatial information, the IPS requires a photonic lantern (PL) to decompose the input multimode light into single modes. This is then fed into either numerous Arrayed Waveguide Gratings (AWGs) or a conventional spectrograph. We investigate the potential advantage of using an IPS instead of conventional monolithic optics for a variety of capabilities represented by existing instruments and others planned for Extremely Large Telescopes. We show that a full I...

  11. Applications of Integrated Photonic Spectrographs in astronomy.

    OpenAIRE

    Harris, R. J.; Allington-Smith, J. R.

    2013-01-01

    One of the problems of producing instruments for extremely large telescopes (ELTs) is that their size (and hence cost) scales rapidly with telescope aperture. To try to break this relation alternative new technologies have been proposed, such as the use of the Integrated Photonic Spectrograph (IPS). Due to their diffraction-limited nature, the IPS is claimed to defeat the harsh scaling law applying to conventional instruments. In contrast to photonic applications, devices for astronomy are no...

  12. Positioning errors and efficiency in fiber spectrographs

    OpenAIRE

    Newman, Peter R.

    2002-01-01

    The use of wide-field multi-object fiber-input spectrographs for large redshift surveys introduces the possibility of variations in the observed signal-to-noise ratio across the survey area due to errors in positioning the fibers with respect to the target image positions, leading to position-dependent errors in the survey catalog. This paper brings together a comprehensive description of the sources of fiber-to-image position errors in different instrument designs, and quantifies their effec...

  13. GYES, a multifibre spectrograph for the CFHT

    CERN Document Server

    Bonifacio, P; Dournaux, J -L; François, P; Caffau, E; Royer, F; Babusiaux, C; Arenou, F; Balkowski, C; Bienaymé, O; Briot, D; Carlberg, R; Cohen, M; Dalton, G B; Famaey, B; Fasola, G; Frémat, Y; Gómez, A; Haywood, M; Hill, V; Huet, J -M; Katz, D; Horville, D; Kudritzky, R; Lallement, R; Laporte, Ph; de Laverny, P; Lemasle, B; Lewis, I J; Martayan, C; Monier, R; Mourard, D; Nardetto, N; Blanco, A Recio; Robichon, N; Robin, A C; Rodrigues, M; Soubiran, C; Turon, C; Venn, K; Viala, Y

    2010-01-01

    We have chosen the name of GYES, one of the mythological giants with one hundred arms, offspring of Gaia and Uranus, for our instrument study of a multifibre spectrograph for the prime focus of the Canada-France-Hawaii Telescope. Such an instrument could provide an excellent ground-based complement for the Gaia mission and a northern complement to the HERMES project on the AAT. The CFHT is well known for providing a stable prime focus environment, with a large field of view, which has hosted several imaging instruments, but has never hosted a multifibre spectrograph. Building upon the experience gained at GEPI with FLAMES-Giraffe and X-Shooter, we are investigating the feasibility of a high multiplex spectrograph (about 500 fibres) over a field of view 1 degree in diameter. We are investigating an instrument with resolution in the range 15000 to 30000, which should provide accurate chemical abundances for stars down to 16th magnitude and radial velocities, accurate to 1 km/s for fainter stars. The study is le...

  14. Islamic Astronomical Instruments and Observatories

    Science.gov (United States)

    Heidarzadeh, Tofigh

    This chapter is a brief survey of astronomical instruments being used and developed in Islamic territories from the eighth to the fifteenth centuries as well as a concise account of major observatories and observational programs in this period.

  15. Sixteenth Century Astronomical Telescopy

    Science.gov (United States)

    Usher, P. D.

    2001-12-01

    Ophelia in Shakespeare's Hamlet is named for the ``moist star" which in mythology is the partner of Hamlet's royal Sun. Together the couple seem destined to rule on earth just as their celestial counterparts rule the heavens, but the tragedy is that they are afflicted, just as the Sun and Moon are blemished. In 1.3 Laertes lectures Ophelia on love and chastity, describing first Cytherean phases (crescent to gibbous) and then Lunar craters. Spots mar the Sun (1.1, 3.1). Also reported are Jupiter's Red Spot (3.4) and the resolution of the Milky Way into stars (2.2). These interpretations are well-founded and support the cosmic allegory. Observations must have been made with optical aid, probably the perspective glass of Leonard Digges, father of Thomas Digges. Notably absent from Hamlet is mention of the Galilean moons, owing perhaps to the narrow field-of-view of the telescope. That discovery is later celebrated in Cymbeline, published soon after Galileo's Siderius Nuncius in 1610. In 5.4 of Cymbeline the four ghosts dance ``in imitation of planetary motions" and at Jupiter's behest place a book on the chest of Posthumus Leonatus. His name identifies the Digges father and son as the source of data in Hamlet since Jupiter's moons were discovered after the deaths of Leonard (``leon+hart") and Thomas (the ``lion's whelp"). Lines in 5.4 urge us not to read more into the book than is contained between its covers; this is understandable because Hamlet had already reported the other data in support of heliocentricism and the cosmic model discussed and depicted by Thomas Digges in 1576. I conclude therefore that astronomical telescopy began in England before the last quarter of the sixteenth century.

  16. Young Astronomers' Observe with ESO Telescopes

    Science.gov (United States)

    1995-11-01

    somewhat similar to the Earth, but it is too cold for life as we know it, and because of its comparatively small size, the atmospheric pressure is very low. It would in principle be possible to detect the outermost planet with the HST, if the distance to this planetary system was less than about 30 light-years. Ireland: Mr. Declan MacCuarta (Teacher), Mr. Colm McLoughlin (St. Peter's College, Wexford, Co. Wexford) The nearest star, Alpha Centauri, is a double star and a hypothetical planetary system around the A-component, a solar-type star, is studied in some detail. The presence of the companion star makes some planetary orbits unstable. In this project, 4 planets are placed within 2 AU (300 million km) of the central star; 3 of these are terrestrial (no. 3 is Earth-like) and the outermost is a small gaseous planet. Cometary orbits may be very complex in this gravitatinal field. A planetary system like the one described may be barely observable with the Hubble Space Telescope, and only if one of the planets passes in front of the star (an `occultation') and its light diminishes accordingly. Italy: Mr. Pasquale Ciarletta, Ms. Francesca D'elia, Ms. Ada Fortugna (Teacher), Mr. Alfredo Pudano (Liceo Scientifico `Leonardo da Vinci', Reggio Calabria) This group built a spectrograph from scratch, with a grating and all the usual optical parts. They were able to calibrate the solar spectrum with the help of standard lamps and in this way, they observed several prominent, solar absorption lines. Among them were the H-alpha line at 6562 A, the sodium D-lines at 5890--96 And the magnesium triplet near 5175 A. These observations were made with the eye and also with the photographic recording technique. They were planning to observe the spectra of some stars also, but in the end time was too short and they had to hurry to send in the report. The Netherlands: Mr. Alex De Beer, Mr. KlAs Huijbregts, Mr. Ruud Nellen (Norbertuscollege, RosendAl) This team has designed their own planetary

  17. SUBARU prime focus spectrograph: integration, testing and performance for the first spectrograph

    CERN Document Server

    Madec, F; Mignant, D Le; Dohlen, K; Barrette, R; Belhadi, M; Pascal, S; Smee, S; Gunn, J; Merrer, J Le; Lorred, M; Jaquet, M; Balard, P; Blanchard, P; Thao, W; Roman, F; Lapere, V; Gabriel, JF; Loomis, C; Golebiowski, M; Hart, M; Oliveira, L; Oliveira, A; Tamura, N; Shimono, A

    2016-01-01

    The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project for Subaru telescope consists in four identical spectrographs fed by 600 fibers each. Each spectrograph is composed by an optical entrance unit that creates a collimated beam and distributes the light to three channels, two visibles and one near infrared. This paper presents the on-going effort for the tests & integration process for the first spectrograph channel: we have developed a detailed Assembly Integration and Test (AIT) plan, as well as the methods, detailed processes and I&T tools. We describe the tools we designed to assemble the parts and to test the performance of the spectrograph. We also report on the thermal acceptance tests we performed on the first visible camera unit. We also report on and discuss the technical difficulties that did appear during this integration phase. Finally, we detail the important logistic process that is require to transport the components from other country t...

  18. Astronomical Receiver Modelling Using Scattering Matrices

    CERN Document Server

    King, O G; Copley, C; Davis, R J; Leahy, J P; Leech, J; Muchovej, S J C; Pearson, T J; Taylor, Angela C

    2014-01-01

    Proper modelling of astronomical receivers is vital: it describes the systematic errors in the raw data, guides the receiver design process, and assists data calibration. In this paper we describe a method of analytically modelling the full signal and noise behaviour of arbitrarily complex radio receivers. We use electrical scattering matrices to describe the signal behaviour of individual components in the receiver, and noise correlation matrices to describe their noise behaviour. These are combined to produce the full receiver model. We apply this approach to a specified receiver architecture: a hybrid of a continous comparison radiometer and correlation polarimeter designed for the C-Band All-Sky Survey. We produce analytic descriptions of the receiver Mueller matrix and noise temperature, and discuss how imperfections in crucial components affect the raw data. Many of the conclusions drawn are generally applicable to correlation polarimeters and continuous comparison radiometers.

  19. Flat-fielding strategy for the JWST/NIRSpec multi-object spectrograph

    Science.gov (United States)

    Rawle, T. D.; Alves de Oliveira, C.; Birkmann, S. M.; Boeker, T.; de Marchi, G.; Ferruit, P.; Giardino, G.; Luetzgendorf, N.; Sirianni, M.

    2016-07-01

    The Near-Infrared Spectrograph (NIRSpec) onboard the James Webb Space Telescope (JWST) will be the first space-borne Multi-Object Spectrograph (MOS), comprising a quarter of a million individually addressable microshutters to allow simultaneous observation of ˜100 targets. We present the strategy for flat-fielding the NIRSpec MOS, correcting for the combined effects of the telescope and instrument throughput as well as the detector response. With a highly configurable shutter array, a novel approach is required to ensure that flat- field reference observations do not significantly impact telescope efficiency. We envisage a two-step strategy: 1) Creation of a three-dimensional master flat-field reference (two spatial dimensions, one wavelength) from a small set of well-designed calibration data; 2) Correction of any data frame using a two-dimensional flat-field generated on-the-fly, for that specific MOS configuration, from the master.

  20. EXPRES: A Next Generation RV Spectrograph in the Search for Earth-like Worlds

    CERN Document Server

    Jurgenson, C; McCracken, T; Sawyer, D; Szymkowiak, A; Davis, A B; Muller, G; Santoro, F

    2016-01-01

    The EXtreme PREcision Spectrograph (EXPRES) is an optical fiber fed echelle instrument being designed and built at the Yale Exoplanet Laboratory to be installed on the 4.3-meter Discovery Channel Telescope operated by Lowell Observatory. The primary science driver for EXPRES is to detect Earth-like worlds around Sun-like stars. With this in mind, we are designing the spectrograph to have an instrumental precision of 15 cm/s so that the on-sky measurement precision (that includes modeling for RV noise from the star) can reach to better than 30 cm/s. This goal places challenging requirements on every aspect of the instrument development, including optomechanical design, environmental control, image stabilization, wavelength calibration, and data analysis. In this paper we describe our error budget, and instrument optomechanical design.

  1. Enthusiastic Little Astronomers

    Science.gov (United States)

    Novak, Ines

    2016-04-01

    Younger primary school students often show great interest in the vast Universe hiding behind the starry night's sky, but don't have a way of learning about it and exploring it in regular classes. Some of them would search children's books, Internet or encyclopedias for information or facts they are interested in, but there are those whose hunger for knowledge would go unfulfilled. Such students were the real initiators of our extracurricular activity called Little Astronomers. With great enthusiasm they would name everything that interests them about the Universe that we live in and I would provide the information in a fun and interactive yet acceptable way for their level of understanding. In our class we learn about Earth and its place in the Solar System, we learn about the planets and other objects of our Solar System and about the Sun itself. We also explore the night sky using programs such as Stellarium, learning to recognize constellations and name them. Most of our activities are done using a PowerPoint presentation, YouTube videos, and Internet simulations followed by some practical work the students do themselves. Because of the lack of available materials and funds, most of materials are hand made by the teacher leading the class. We also use the school's galileoscope as often as possible. Every year the students are given the opportunity to go to an observatory in a town 90 km away so that they could gaze at the sky through the real telescope for the first time. Our goal is to start stepping into the world of astronomy by exploring the secrets of the Universe and understanding the process of rotation and revolution of our planet and its effects on our everyday lives and also to become more aware of our own role in our part of the Universe. The hunger for knowledge and enthusiasm these students have is contagious. They are becoming more aware of their surroundings and also understanding their place in the Universe that helps them remain humble and helps

  2. The New Amateur Astronomer

    Science.gov (United States)

    Mobberley, Martin

    Amateur astronomy has changed beyond recognition in less than two decades. The reason is, of course, technology. Affordable high-quality telescopes, computer-controlled 'go to' mountings, autoguiders, CCD cameras, video, and (as always) computers and the Internet, are just a few of the advances that have revolutionized astronomy for the twenty-first century. Martin Mobberley first looks at the basics before going into an in-depth study of what’s available commercially. He then moves on to the revolutionary possibilities that are open to amateurs, from imaging, through spectroscopy and photometry, to patrolling for near-earth objects - the search for comets and asteroids that may come close to, or even hit, the earth. The New Amateur Astronomer is a road map of the new astronomy, equally suitable for newcomers who want an introduction, or old hands who need to keep abreast of innovations. From the reviews: "This is one of several dozen books in Patrick Moore's "Practical Astronomy" series. Amid this large family, Mobberley finds his niche: the beginning high-tech amateur. The book's first half discusses equipment: computer-driven telescopes, CCD cameras, imaging processing software, etc. This market is changing every bit as rapidly as the computer world, so these details will be current for only a year or two. The rest of the book offers an overview of scientific projects that serious amateurs are carrying out these days. Throughout, basic formulas and technical terms are provided as needed, without formal derivations. An appendix with useful references and Web sites is also included. Readers will need more than this book if they are considering a plunge into high-tech amateur astronomy, but it certainly will whet their appetites. Mobberley's most valuable advice will save the book's owner many times its cover price: buy a quality telescope from a reputable dealer and install it in a simple shelter so it can be used with as little set-up time as possible. A poor

  3. Astronomical forcing and geochronological application of sedimentary cycles in the Mediterranean Pliocene-Pleistocene

    OpenAIRE

    Hilgen, Frits

    1991-01-01

    A new, astronomically calibrated time scale is presented for the Mediterranean Pliocene based on the correlation of sedimentary cycles to astronomical curves which describe the quasi-periodic variations in the Earth's orbit during the last 5.5 Ma. These sedimentary cycles are found in a continuous deep-sea marl sequence emerged above present sea-level due to tectonic uplift. For this sequence, an integrated high-resolution magnetostratigraphy, (planktonic foraminiferal) biostratigraphy and li...

  4. Choosing and using astronomical eyepieces

    CERN Document Server

    Paolini, William

    2013-01-01

    This valuable reference fills a number of needs in the field of astronomical eyepieces, including that of a buyer's guide, observer's field guide and technical desk reference. It documents the past market for eyepieces and its evolution right up to the present day. In addition to appealing to practical astronomers - and potentially saving them money - it is useful both as a historical reference and as a detailed review of the current market place for this bustling astronomical consumer product. What distinguishes this book from other publications on astronomy is the involvement of observers from all aspects of the astronomical community, and also the major manufacturers of equipment. It not only catalogs the technical aspects of the many modern eyepieces but also documents amateur observer reactions and impressions of their utility over the years, using many different eyepieces. Eyepieces are the most talked-about accessories and collectible items available to the amateur astronomer. No other item of equi...

  5. Upgrade of the area II spectrograph

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E.; Bolduc, C.

    1995-08-01

    Because of the low beam energies required for experiments of astrophysical interest, the first test experiments with radioactive {sup 18}F beams can be performed in Area II. Because of the shorter distances between ion source and detector this also results in higher transmission efficiencies. The Enge split-pole spectrograph, which was not used during the last 8 years, was equipped with a new cryopump system, upgrades to the magnet power supply and the NMR system were performed. A rotating target system was built which should alleviate target deterioration effects that were observed in first test experiments.

  6. High resolution magnetic spectrograph 'Grand Raiden'

    International Nuclear Information System (INIS)

    In the report of the last 1988, the basic design of a new high resolution (p/Δp = 37750) magnetic spectrograph of the type QSQDMD (+D), named 'Grand Raiden', was presented. Here, we show results of more detailed ray-tracing calculations; the focal line property, the image aberration, and the compensation of the kinematic broadening by multipole fields. The final design of the new DSR (dipole for spin rotation) for the measurement of in-plane spin observables are also reported. (author)

  7. Astronomical Image and Data Analysis

    CERN Document Server

    Starck, J.-L

    2006-01-01

    With information and scale as central themes, this comprehensive survey explains how to handle real problems in astronomical data analysis using a modern arsenal of powerful techniques. It treats those innovative methods of image, signal, and data processing that are proving to be both effective and widely relevant. The authors are leaders in this rapidly developing field and draw upon decades of experience. They have been playing leading roles in international projects such as the Virtual Observatory and the Grid. The book addresses not only students and professional astronomers and astrophysicists, but also serious amateur astronomers and specialists in earth observation, medical imaging, and data mining. The coverage includes chapters or appendices on: detection and filtering; image compression; multichannel, multiscale, and catalog data analytical methods; wavelets transforms, Picard iteration, and software tools. This second edition of Starck and Murtagh's highly appreciated reference again deals with to...

  8. Choosing and using astronomical filters

    CERN Document Server

    Griffiths, Martin

    2014-01-01

    As a casual read through any of the major amateur astronomical magazines will demonstrate, there are filters available for all aspects of optical astronomy. This book provides a ready resource on the use of the following filters, among others, for observational astronomy or for imaging: Light pollution filters Planetary filters Solar filters Neutral density filters for Moon observation Deep-sky filters, for such objects as galaxies, nebulae and more Deep-sky objects can be imaged in much greater detail than was possible many years ago. Amateur astronomers can take

  9. Two amateur astronomers at Berkeley

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    The book on Mechanics of the Physics at Berkeley, by C. Kittel, W.D. Knight and M.A. Ruderman, is proposing at the end of its first chapter some problems of simple astronomy within the solar system. The discussion begins with two amateur astronomers who set for themselves the goal of determining the diameter and mass of the Sun. Here we discuss the problems proposed by the book and some other matters on ancient and modern astronomical studies of the solar system.

  10. LRS2: A New Integral Field Spectrograph for the HET

    Science.gov (United States)

    Tuttle, Sarah E.; Hill, Gary J.; Chonis, Taylor S.; Tonnesen, Stephanie

    2016-01-01

    Here we present LRS2 (Low Resolution Spectrograph) and highlight early science opportunities with the newly upgraded Hobby Eberly telescope (HET). LRS2 is a four-channel optical wavelength (370nm - 1micron) spectrograph based on two VIRUS unit spectrographs. This fiber-fed integral field spectrograph covers a 12" x 6" field of view, switched between the two units (one blue, and one red) at R~2000. We highlight design elements, including the fundamental modification to grisms (from VPH gratings in VIRUS) to access the higher resolution. We discuss early science opportunities, including investigating nearby "blue-bulge" spiral galaxies and their anomalous star formation distribution.

  11. The deterministic optical alignment of the HERMES spectrograph

    Science.gov (United States)

    Gers, Luke; Staszak, Nicholas

    2014-07-01

    The High Efficiency and Resolution Multi Element Spectrograph (HERMES) is a four channel, VPH-grating spectrograph fed by two 400 fiber slit assemblies whose construction and commissioning has now been completed at the Anglo Australian Telescope (AAT). The size, weight, complexity, and scheduling constraints of the system necessitated that a fully integrated, deterministic, opto-mechanical alignment system be designed into the spectrograph before it was manufactured. This paper presents the principles about which the system was assembled and aligned, including the equipment and the metrology methods employed to complete the spectrograph integration.

  12. Field Raman Spectrograph for Environmental Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sylvia, J.M.; Haas, J.W.; Spencer, K.M.; Carrabba, M.M.; Rauh, R.D.; Forney, R.W.; Johnston, T.M.

    1998-07-01

    The widespread contamination found across the US Department of Energy (DOE) complex has received considerable attention from the government and public alike. A massive site characterization and cleanup effort has been underway for several years and is expected to continue for several decades more. The scope of the cleanup effort ranges from soil excavation and treatment to complete dismantling and decontamination of whole buildings. To its credit, DOE has supported research and development of new technologies to speed up and reduce the cost of this effort. One area in particular has been the development of portable instrumentation that can be used to perform analytical measurements in the field. This approach provides timely data to decision makers and eliminates the expense, delays, and uncertainties of sample preservation, transport, storage, and laboratory analysis. In this program, we have developed and demonstrated in the field a transportable, high performance Raman spectrograph that can be used to detect and identify contaminants in a variety of scenarios. With no moving parts, the spectrograph is rugged and can perform many Raman measurements in situ with flexible fiber optic sampling probes. The instrument operates under computer control and a software package has been developed to collect and process spectral data. A collection of Raman spectra for 200 contaminants of DOE importance has been compiled in a searchable format to assist in the identification of unknown contaminants in the field.

  13. The Interface Region Imaging Spectrograph (IRIS)

    CERN Document Server

    De Pontieu, B; Lemen, J; Kushner, G D; Akin, D J; Allard, B; Berger, T; Boerner, P; Cheung, M; Chou, C; Drake, J F; Duncan, D W; Freeland, S; Heyman, G F; Hoffman, C; Hurlburt, N E; Lindgren, R W; Mathur, D; Rehse, R; Sabolish, D; Seguin, R; Schrijver, C J; Tarbell, T D; Wuelser, J -P; Wolfson, C J; Yanari, C; Mudge, J; Nguyen-Phuc, N; Timmons, R; van Bezooijen, R; Weingrod, I; Brookner, R; Butcher, G; Dougherty, B; Eder, J; Knagenhjelm, V; Larsen, S; Mansir, D; Phan, L; Boyle, P; Cheimets, P N; DeLuca, E E; Golub, L; Gates, R; Hertz, E; McKillop, S; Park, S; Perry, T; Podgorski, W A; Reeves, K; Saar, S; Testa, P; Tian, H; Weber, M; Dunn, C; Eccles, S; Jaeggli, S A; Kankelborg, C C; Mashburn, K; Pust, N; Springer, L; Carvalho, R; Kleint, L; Marmie, J; Mazmanian, E; Pereira, T M D; Sawyer, S; Strong, J; Worden, S P; Carlsson, M; Hansteen, V H; Leenaarts, J; Wiesmann, M; Aloise, J; Chu, K -C; Bush, R I; Scherrer, P H; Brekke, P; Martinez-Sykora, J; Lites, B W; McIntosh, S W; Uitenbroek, H; Okamoto, T J; Gummin, M A; Auker, G; Jerram, P; Pool, P; Waltham, N

    2014-01-01

    The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33-0.4 arcsec spatial resolution, 2 s temporal resolution and 1 km/s velocity resolution over a field-of-view of up to 175 arcsec x 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332-1358, 1389-1407 and 2783-2834 Angstrom including bright spectral lines formed in the chromosphere (Mg II h 2803 Angstrom and Mg II k 2796 Angstrom) and transition region (C II 1334/1335 Angstrom and Si IV 1394/1403 Angstrom). Slit-jaw images in four different passbands (C II 1330, Si IV 1400, Mg II k 2796 and Mg II wing 2830 Angstrom) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec x 175 arcsec at a variety of spatial sa...

  14. The new 2meter RCC Telescope in the Northern CAucasus (3100m) for Modern Astronomical Research

    Science.gov (United States)

    Tarady, V.; Yatskiv, Ya.

    A new 2 meter Ritchey-Chretien-Coude telescope in the Northern Caucasus is expected to be ready for astronomical research in late 1995. The telescope is located on the Terskol peak (near Elbrus) with the altitude of 3100 meter. The low atmospheric water vapour content and the high air transparency in the ultraviolet region allow us to infer that the Terskol peak is one of the best sites in Europe for astronomical ground observation. The mean seeing is about 1 arcsec at the Terskol peak. The main parameters of the optical system are as follows: * equivalent focal length is 16000 mm for the Ritchey-Chretien system and 72000 mm for the Coude system; * diameter of the field free from vignetting is 108' for the Ritchey-Chretien system and 5' for another one; *spot concentration is 80% inside the 0.5" circle. The new telescope will be used in investigating the fundamental problems of the star brightness variability, physics of stars and galaxies, studying the planet and satellite atmosphere dynamics. The precise astrometrical problems can also be solved with this telescope. The telescope will be equiped with the following detectors: -CCD Echelle spectrograph in the Coude focus; - astronomical infrared Fourie spectrometre; -digital panoramic polarimeter; -panoramic spectrophotometer with Fabry-Perot interferometer. This project is realized by the joint efforts of the Main Astronomical Observatory in Kiev (Ukrainian Academy of Sciences) and the International Centre for Astronomical and Medical-Ecological Investigations. Proposals for Scientific observation at the Terskol Observatory are encouraged.

  15. Temperature control system for optical elements in astronomical instrumentation

    Science.gov (United States)

    Verducci, Orlando; de Oliveira, Antonio C.; Ribeiro, Flávio F.; Vital de Arruda, Márcio; Gneiding, Clemens D.; Fraga, Luciano

    2014-07-01

    Extremely low temperatures may damage the optical components assembled inside of an astronomical instrument due to the crack in the resin or glue used to attach lenses and mirrors. The environment, very cold and dry, in most of the astronomical observatories contributes to this problem. This paper describes the solution implemented at SOAR for remotely monitoring and controlling temperatures inside of a spectrograph, in order to prevent a possible damage of the optical parts. The system automatically switches on and off some heat dissipation elements, located near the optics, as the measured temperature reaches a trigger value. This value is set to a temperature at which the instrument is not operational to prevent malfunction and only to protect the optics. The software was developed with LabVIEWTM and based on an object-oriented design that offers flexibility and ease of maintenance. As result, the system is able to keep the internal temperature of the instrument above a chosen limit, except perhaps during the response time, due to inertia of the temperature. This inertia can be controlled and even avoided by choosing the correct amount of heat dissipation and location of the thermal elements. A log file records the measured temperature values by the system for operation analysis.

  16. Creating Data that Never Die: Building a Spectrograph Data Pipeline in the Virtual Observatory Era

    Science.gov (United States)

    Mink, D. J.; Wyatt, W. F.; Roll, J. B.; Tokarz, S. P.; Conroy, M. A.; Caldwell, N.; Kurtz, M.; Geller, M. J.

    2005-12-01

    Data pipelines for modern complex astronomical instruments do not begin when the data is taken and end when it is delivered to the user. Information must flow between the observatory and the observer from the time a project is conceived and between the observatory and the world well past the time when the original observers have extracted all the information they want from the data. For the 300-fiber Hectospec low dispersion spectrograph on the MMT, the SAO Telescope Data Center is constructing a data pipeline which provides assistance from preparing and submitting observing proposals through observation, reduction, and analysis to publication and an afterlife in the Virtual Observatory. We will describe our semi-automatic pipeline and how it has evolved over the first nine months of operation.

  17. Toward accurate radial velocities with the fiber-fed GIRAFFE multi-object VLT spectrograph

    Science.gov (United States)

    Royer, Frederic; Blecha, Andre; North, Pierre; Simond, Gilles; Baratchart, Sebastien; Cayatte, Veronique; Chemin, Laurent; Palsa, Ralf

    2002-12-01

    We describe briefly the Data-Reduction of the VLT fiber-fed multi-object GIRAFFE spectrograph - part of the VLT FLAMES facility. We focus on specific features of GIRAFFE - the simultaneous wavelength calibration - and their impact on the data-reduction strategy. We describe the implementation of the global physical model and we compare the results obtained with the simulated, laboratory and preliminary data. We discuss the influence of critical parameters, the overall accuracy of the wavelength solution, and the stability and the robustness of the global model approach. We address the accuracy of radial velocity measurements illustrated by solar spectra obtained during the Preliminary Acceptance in Europe.

  18. American Astronomical Society Honors NRAO Scientist

    Science.gov (United States)

    2005-01-01

    built in the late 1970s. Work on the package began in 1978 in Charlottesville. Now including nearly a million lines of program code and almost a half-million lines of documentation, AIPS is used at more than 500 sites around the world. The package is a mainstay and a daily tool for most of the world's radio astronomers, and also has been used by scientists in such other fields as fluid-dynamics simulation and medical imaging. Over the years, Greisen and his colleagues at NRAO have revised the AIPS package numerous times and expanded its capabilities as new astronomical and computing hardware was developed. The software has been kept independent of specific computing hardware and operating systems, and so has been successfully used on a wide variety of computing equipment. "We are extremely proud of Eric's work and congratulate him on receiving this award," said NRAO Director Dr. Fred K.Y. Lo. "He has shown extraordinary dedication to making AIPS a valuable and effective tool for the world astronomical community, and this award is well-deserved recognition." The AAS citation reads, "The 2005 Van Biesbroeck Prize is awarded to Dr. Eric Greisen of NRAO for the initiation, development, and maintenance for twenty-five years of the Astronomical Image Processing System (AIPS). Virtually every VLA and VLBA program relies on AIPS for calibration and image reconstruction, and it has been exported to more than 500 sites worldwide. Greisen, as its principal architect and tireless custodian, has provided an invaluable service to astronomy. Moreover, AIPS represented a new paradigm for the processing of massive astronomical datasets, i.e., a comprehensive software package that was rigorously independent of particular operating systems, which supported portability and adaptability to evolving hardware designs. Beyond the call of duty, Greisen has generously responded to individual queries about the code from users at all levels, sometimes in real time at odd hours to support

  19. The use of object-oriented techniques and CORBA in astronomical instrumentation control systems

    Science.gov (United States)

    Dipper, Nigel A.; Blackburn, Colin

    2004-09-01

    Control software for astronomy matches the ever increasing complexity of new large instrumentation projects. In order to speed the development cycle, object-oriented techniques have been used to generate loosely coupled software objects and larger scale components that can be reused in future projects. Such object-oriented systems provide for short development cycles which can respond to changing requirements and allow for extension. The Unified Modeling Language (UML) has been used for the analysis, design and implementation of this software. A distributed system is supported by the use of an object broker such as CORBA. These techniques are being applied to the development of an instrument control system for the UK spectrograph within FMOS (Fiber-fed Multi-Object Spectrograph). This is a second generation instrument for the Subaru Telescope of the National Astronomical Observatory of Japan.

  20. Australian sites of astronomical heritage

    Science.gov (United States)

    Stevenson, T.; Lomb, N.

    2015-03-01

    The heritage of astronomy in Australia has proven an effective communication medium. By interpreting science as a social and cultural phenomenon new light is thrown on challenges, such as the dispersal of instruments and problems identifying contemporary astronomy heritage. Astronomers are asked to take note and to consider the communication of astronomy now and in the future through a tangible heritage legacy.

  1. An Astronomical Data Analyzing Monitor

    Science.gov (United States)

    Teuber, D.

    ThP need for exchange of programmes and data between astronomical facilities is generally recognized, but practicable concepts concerning its realization are rare. Standardization of data formats through FITS is widely accepted; for (interactive) programs, however, identical hardware configurations seem to be the favoured solution. As an alternative, a software approach to the problem is presented.

  2. The PRL Stabilized High Resolution Echelle Fiber-fed Spectrograph: Instrument Description & First Radial Velocity Results

    CERN Document Server

    Chakraborty, Abhijit; Roy, Arpita; Dixit, Vaibhav; Richardson, Eric Harvey; Dongre, Varun; Pathan, F M; Chaturvedi, Priyanka; Shah, Vishal; Ubale, Girish P; Anandarao, B G

    2013-01-01

    We present spectrograph design details and initial radial velocity results from the PRL optical fiber-fed high-resolution cross-dispersed echelle spectrograph (PARAS), which has recently been commissioned at the Mt Abu 1.2 m telescope, in India. Data obtained as part of the post-commissioning tests with PARAS show velocity precision better than 2m/s over a period of several months on bright RV standard stars. For observations of sigma-Dra we report 1.7m/s precision for a period of seven months and 2.1m/s for HD 9407 over a period of 2 months. PARAS is capable of a single-shot spectral coverage of 3800A - 9500A at a resolution of about 67,000. The RV results were obtained between 3800A and 6900A using simultaneous wavelength calibration with a Thorium-Argon (ThAr) hollow cathode lamp. The spectrograph is maintained under stable conditions of temperature with a precision of 0.01 - 0.02C (rms) at 25.55C, and enclosed in a vacuum vessel at pressure of 0.1 +/-0.03 mbar. The blaze peak efficiency of the spectrograp...

  3. The InfraRed Imaging Spectrograph (IRIS) for TMT: Overview of innovative science programs

    CERN Document Server

    Wright, Shelley A; Moore, Anna M; Do, Tuan; Simard, Luc; Adamkovics, Mate; Armus, Lee; Barth, Aaron J; Barton, Elizabeth; Cooke, Hope Boyce Jeffrey; Cote, Patrick; Davidge, Timothy; Ellerbroek, Brent; Ghez, Andrea; Liu, Michael C; Lu, Jessica R; Macintosh, Bruce A; Mao, Shude; Marois, Christian; Schoeck, Mathias; Suzuki, Ryuji; Tan, Jonathan C; Treu, Tommaso; Wang, Lianqi; Weiss, Jason

    2014-01-01

    IRIS (InfraRed Imaging Spectrograph) is a first light near-infrared diffraction limited imager and integral field spectrograph being designed for the future Thirty Meter Telescope (TMT). IRIS is optimized to perform astronomical studies across a significant fraction of cosmic time, from our Solar System to distant newly formed galaxies (Barton et al. [1]). We present a selection of the innovative science cases that are unique to IRIS in the era of upcoming space and ground-based telescopes. We focus on integral field spectroscopy of directly imaged exoplanet atmospheres, probing fundamental physics in the Galactic Center, measuring 10^4 to 10^10 Msun supermassive black hole masses, resolved spectroscopy of young star-forming galaxies (1 < z < 5) and first light galaxies (6 < z < 12), and resolved spectroscopy of strong gravitational lensed sources to measure dark matter substructure. For each of these science cases we use the IRIS simulator (Wright et al. [2], Do et al. [3]) to explore IRIS capabi...

  4. Spectroscopic Survey of Eclipsing Binaries with a Low Cost \\'{E}chelle Spectrograph -- Scientific Commissioning

    CERN Document Server

    Kozłowski, Stanisław K; Sybilski, Piotr; Ratajczak, Milena; Pawłaszek, Rafał K; Hełminiak, Krzysztof G

    2016-01-01

    We present scientific results obtained with a recently commissioned \\'{e}chelle spectrograph on the 0.5-m Solaris-1 telescope in the South African Astronomical Observatory. BACHES is a low-cost slit \\'{e}chelle spectrograph that has a resolution of 21,000 at 5,500 \\AA. The described setup is fully remotely operated and partly automated. Custom hardware components have been designed to allow both spectroscopic and photometric observations. The setup is controlled via dedicated software. The throughput of the system allows us to obtain spectra with an average SNR of 22 at 6375 {\\AA} for a 30-min exposure of a $V=10$ mag target. The stability of the instrument is influenced mainly by the ambient temperature changes. We have obtained radial velocity RMS values for a bright (V = 5.9 mag) spectroscopic binary as good as 0.59 km s$^{-1}$ and 1.34 km s$^{-1}$ for a $V = 10.2$ mag eclipsing binary. Radial velocity measurements have been combined with available photometric light curves. We present models of six eclipsi...

  5. Spectroscopic Survey of Eclipsing Binaries with a Low-cost Echelle Spectrograph: Scientific Commissioning

    Science.gov (United States)

    Kozłowski, S. K.; Konacki, M.; Sybilski, P.; Ratajczak, M.; Pawłaszek, R. K.; Hełminiak, K. G.

    2016-07-01

    We present scientific results obtained with a recently commissioned échelle spectrograph on the 0.5 m Solaris-1 telescope in the South African Astronomical Observatory. BACHES is a low-cost slit échelle spectrograph that has a resolution of 21,000 at 5500 Å. The described setup is fully remotely operated and partly automated. Custom hardware components have been designed to allow both spectroscopic and photometric observations. The setup is controlled via dedicated software. The throughput of the system allows us to obtain spectra with an average signal-to-noise ratio of 22 at 6375 Å for a 30 minute exposure of a V = 10 mag target. The stability of the instrument is influenced mainly by the ambient temperature changes. We have obtained radial velocity (RV) rms values for a bright (V = 5.9 mag) spectroscopic binary as good as 0.59 and 1.34 km s‑1 for a V = 10.2 mag eclipsing binary. RV measurements have been combined with available photometric light curves. We present models of six eclipsing binary systems, and for previously known targets, we compare our results with those available in the literature. Masses of binary components have been determined with 3% errors for some targets. We confront our results with benchmark values based on measurements from the HARPS and UCLES spectrographs on 4 m class telescopes and find very good agreement. The described setup is very efficient and well suited for a spectroscopic survey. We can now spectroscopically characterize about 300 eclipsing binary stars per year up to 10.2 mag assuming typical weather conditions at SAAO without a single observing trip.

  6. Spectroscopic Survey of Eclipsing Binaries with a Low-cost Echelle Spectrograph: Scientific Commissioning

    Science.gov (United States)

    Kozłowski, S. K.; Konacki, M.; Sybilski, P.; Ratajczak, M.; Pawłaszek, R. K.; Hełminiak, K. G.

    2016-07-01

    We present scientific results obtained with a recently commissioned échelle spectrograph on the 0.5 m Solaris-1 telescope in the South African Astronomical Observatory. BACHES is a low-cost slit échelle spectrograph that has a resolution of 21,000 at 5500 Å. The described setup is fully remotely operated and partly automated. Custom hardware components have been designed to allow both spectroscopic and photometric observations. The setup is controlled via dedicated software. The throughput of the system allows us to obtain spectra with an average signal-to-noise ratio of 22 at 6375 Å for a 30 minute exposure of a V = 10 mag target. The stability of the instrument is influenced mainly by the ambient temperature changes. We have obtained radial velocity (RV) rms values for a bright (V = 5.9 mag) spectroscopic binary as good as 0.59 and 1.34 km s-1 for a V = 10.2 mag eclipsing binary. RV measurements have been combined with available photometric light curves. We present models of six eclipsing binary systems, and for previously known targets, we compare our results with those available in the literature. Masses of binary components have been determined with 3% errors for some targets. We confront our results with benchmark values based on measurements from the HARPS and UCLES spectrographs on 4 m class telescopes and find very good agreement. The described setup is very efficient and well suited for a spectroscopic survey. We can now spectroscopically characterize about 300 eclipsing binary stars per year up to 10.2 mag assuming typical weather conditions at SAAO without a single observing trip.

  7. Engaging Students through Astronomically Inspired Music

    Science.gov (United States)

    Whitehouse, M.

    2011-09-01

    This paper describes a lesson outline in which astronomically inspired musical compositions are used to teach astronomical concepts via an introductory activity, close listening, and critical/creative reflection.

  8. The astronomical tables of Giovanni Bianchini

    CERN Document Server

    Chabas, Jose

    2009-01-01

    This book describes and analyses, for the first time, the astronomical tables of Giovanni Bianchini of Ferrara (d. after 1469), explains their context, inserts them into an astronomical tradition that began in Toledo, and addresses their diffusion.

  9. Interactive Visualization and Simulation of Astronomical Nebulae

    CERN Document Server

    Wenger, Stephan; Steffen, Wolfgang; Koning, Nico; Weiskopf, Daniel; Magnor, Marcus

    2012-01-01

    Interactive visualization and simulation of astrophysical phenomena help astronomers and enable digital planetariums and television documentaries to take their spectators on a journey into deep space to explore the astronomical wonders of our universe in 3D.

  10. Near ultraviolet spectrograph for balloon platform

    Science.gov (United States)

    Sreejith, A. G.; Safonova, Margarita; Murthy, Jayant

    2015-06-01

    Small and compact scientific payloads may be easily designed constructed and own on high altitude balloons. Despite the fact that large orbital observatories provide accurate observations and statistical studies of remote and/or faint space sources, small telescopes on board balloons or rockets are still attractive because of their low cost and rapid response time. We describe here a near ultraviolet (NUV) spectrograph designed to be own on a high{altitude balloon platform. Our basic optical design is a modified Czerny-Turner system using off the shelf optics. We compare different methods of aberration corrections in such a system. We intend the system to be portable and scalable to different telescopes. The use of reflecting optics reduces the transmission loss in UV. We plan on using an image intensified CMOS sensor operating in photon counting mode as the detector of choice.

  11. Spectrographic determination of impurities in beryllium oxide

    International Nuclear Information System (INIS)

    A method for the spectrographic determination of Al, B, Cd, Co, Cu, Cr, Fe, Mg, NaNi, Si and Zn in nuclear grade beryllium oxide has been developed. The determination of Co, Al, Na and Zn is besed upon a carrier distillation technique. Better results were obtained with 2% Ga2O3 as carrier in beryllium oxide. For the elements B, Cd, Cu, Fe, Cr, Mg, Ni and Si the sample is loaded in a Scribner-Mullin shallow cup electrode, covered with graphite powder and excited in DC arc. The relative standard deviation values for different elements are in the range of 10 to 20%. The method fulfills requirements of precision and sensitivity for specification analysis of nuclear grade beryllium oxide.(Author)

  12. First light results from the Hermes spectrograph at the AAT

    NARCIS (Netherlands)

    Sheinis, A.; Barden, S.; Birchall, M.; Carollo, D.; Bland-Hawthorn, J.; Brzeski, J.; Case, S.; Cannon, R.; Churilov, V.; Couch, W.; Dean, R.; De Silva, G.; D'Orazi, V.; Farrell, T.; Fiegert, K.; Freeman, K.; Frost, G.; Gers, L.; Goodwin, M.; Gray, D.; Heald, R.; Heijmans, J.A.C.; Jones, D.; Keller, S.; Klauser, U.; Kondrat, Y.; Lawrence, J.; Lee, S.; Mali, S.; Martell, S.; Mathews, D.; Mayfield, D.; Miziarski, S.; Muller, R.; Pai, N.; Patterson, R.; Penny, E.; Orr, D.; Shortridge, K.; Simpson, J.; Smedley, S.; Smith, G.; Stafford, D.; Staszak, N.; Vuong, M.; Waller, L.; Wylie de Boer, E.; Xavier, P.; Zheng, J.; Zhelem, R.; Zucker, D.

    2014-01-01

    The High Efficiency and Resolution Multi Element Spectrograph, HERMES is an facility-class optical spectrograph for the AAT. It is designed primarily for Galactic Archeology [21], the first major attempt to create a detailed understanding of galaxy formation and evolution by studying the history of

  13. Quantitative imaging through a spectrograph. 1. Principles and theory.

    NARCIS (Netherlands)

    Tolboom, R.A.L.; Dam, N.J.; Meulen, J.J. ter; Mooij, J.M.; Maassen, J.D.M.

    2004-01-01

    Laser-based optical diagnostics, such as planar laser-induced fluorescence and, especially, Raman imaging, often require selective spectral filtering. We advocate the use of an imaging spectrograph with a broad entrance slit as a spectral filter for two-dimensional imaging. A spectrograph in this mo

  14. A multipurpose fiber-fed VPHG spectrograph for LAMOST

    Science.gov (United States)

    Zhu, Yongtian; Hu, Zhongwen; Zhang, Qingfeng; Wang, Lei; Wang, Jianing

    2006-06-01

    A multipurpose fiber-fed double-beam Schmidt spectrograph using VPHG (volume phase holographic gratings) is under construction for LAMOST (The Large Sky Area Multi-Object Fiber Spectroscopic Telescope). There are 16 such spectrographs (hereafter referred to as LRSs) for the project. The spectrographs are designed with wavelength coverage from 370 to 900 nm, with spectral resolutions of 1000-10000, and with multi-object capability over a 5 degrees field of view. Each spectrograph will be accommodating 250 fibers of 320 microns diameter (corresponding 3.3 arcsecs). The 200 mm diameter collimated beam is split into two separate channels. The blue channel is optimized for 370nm-590nm, and the red channel for 570nm-900nm. The LRS can work in several varied resolution modes. The optical design and performance is described. The spectrograph is of simple design with moderate image quality and good throughput. Progress on the construction of LRS is reported as well.

  15. Optimizing energy resolution in accelerator-spectrograph systems

    International Nuclear Information System (INIS)

    This paper describes the optimization of energy resolution in magnetic spectrograph systems and at the same time compares two significantly different systems, HHH and VHV systems. In the first, HHH, we have in the same plane, the incident beam dispersion, the nuclear reaction or scattering, and the spectrograph analysis, the plane being commonly the Horziontal plane. In the second scheme, VHV, which is the case for the Los Alamos HRS (High Resolution Spectrograph), the incident beam dispersion and the analysis of the reaction products by the spectrograph are in one plane (vertical), while the reaction plane is an orthogonal plane (horizontal). This latter scheme, VHV, has been selected for the high resolution 1.2 GeV/c spectrograph to be used in the study of heavy-ion reactions at the National Superconducting Cyclotron Laboratory (NSCL) which is being constructed on the campus of Michigan State University

  16. Magnetic spectrograph for the Holifield heavy ion research facility

    International Nuclear Information System (INIS)

    The need for a new generation magnetic spectrograph for the Holifield Heavy Ion Research Facility is discussed. The advantages of a magnetic spectrograph for heavy ion research are discussed, as well as some of the types of experiments for which such an instrument is suited. The limitations which the quality of the incident beam, target and spectrograph itself impose on high resolution heavy ion measurements are discussed. Desired features of an ideal new spectrograph are: (1) intrinsic resolving power E/ΔE greater than or equal to 3000; (2) maximum solid angle greater than or equal to 20 msr; (3) dispersion approx. 4-8m; (4) maximum energy interval approx. 30%; and (5) mass-energy product greater than or equal to 200. Various existing and proposed spectrographs are compared with the specifications for a new heavy ion magnet design

  17. Developments in high-density Cobra fiber positioners for the Subaru Telescope's Prime Focus Spectrograph

    CERN Document Server

    Fisher, Charles D; Kaluzny, Joel V; Seiffert, Michael D; Dekany, Richard G; Ellis, Richard S; Smith, Roger M

    2012-01-01

    The Prime Focus Spectrograph (PFS) is a fiber fed multi-object spectrometer for the Subaru Telescope that will conduct a variety of targeted surveys for studies of dark energy, galaxy evolution, and galactic archaeology. The key to the instrument is a high density array of fiber positioners placed at the prime focus of the Subaru Telescope. The system, nicknamed "Cobra", will be capable of rapidly reconfiguring the array of 2394 optical fibers to the image positions of astronomical targets in the focal plane with high accuracy. The system uses 2394 individual "SCARA robot" mechanisms that are 7.7mm in diameter and use 2 piezo-electric rotary motors to individually position each of the optical fibers within its patrol region. Testing demonstrates that the Cobra positioner can be moved to within 5{\\mu}m of an astronomical target in 6 move iterations with a success rate of 95 per cent. The Cobra system is a key aspect of PFS that will enable its unprecedented combination of high-multiplex factor and observing ef...

  18. National Astronomical Observatory of Japan

    CERN Document Server

    Haubold, Hans J; UN/ESA/NASA Workshop on the International Heliophysical Year 2007 and Basic Space Science, hosted by the National Astronomical Observatory of Japan

    2010-01-01

    This book represents Volume II of the Proceedings of the UN/ESA/NASA Workshop on the International Heliophysical Year 2007 and Basic Space Science, hosted by the National Astronomical Observatory of Japan, Tokyo, 18 - 22 June, 2007. It covers two programme topics explored in this and past workshops of this nature: (i) non-extensive statistical mechanics as applicable to astrophysics, addressing q-distribution, fractional reaction and diffusion, and the reaction coefficient, as well as the Mittag-Leffler function and (ii) the TRIPOD concept, developed for astronomical telescope facilities. The companion publication, Volume I of the proceedings of this workshop, is a special issue in the journal Earth, Moon, and Planets, Volume 104, Numbers 1-4, April 2009.

  19. Astronomical optics and elasticity theory

    CERN Document Server

    Lemaitre, Gerard Rene

    2008-01-01

    Astronomical Optics and Elasticity Theory provides a very thorough and comprehensive account of what is known in this field. After an extensive introduction to optics and elasticity, the book discusses variable curvature and multimode deformable mirrors, as well as, in depth, active optics, its theory and applications. Further, optical design utilizing the Schmidt concept and various types of Schmidt correctors, as well as the elasticity theory of thin plates and shells are elaborated upon. Several active optics methods are developed for obtaining aberration corrected diffraction gratings. Further, a weakly conical shell theory of elasticity is elaborated for the aspherization of grazing incidence telescope mirrors. The very didactic and fairly easy-to-read presentation of the topic will enable PhD students and young researchers to actively participate in challenging astronomical optics and instrumentation projects.

  20. Geopulsation, Volcanism and Astronomical Periods

    Institute of Scientific and Technical Information of China (English)

    Yang Xuexiang; Chen Dianyou; Yang Xiaoying; Yang Shuchen

    2000-01-01

    Volcanism is mainly controlled by the intermittent release of energy in the earth. As far as the differential rotation of the earth's inner core is concerned, the Galactic Year may change the gravitational constant G, the solar radiative quantity and the moving speed of the solar system and affect the exchange of angular momentum between core and mantle as well as the energy exchange between crust and mantle. As a result, this leads to eruptions of superplumes and magma, and controls the energy flow from core - mantle boundary (CMB) to crust. When the earth' s speed decreases, it will release a huge amount of energy. They are the reason of the correspondence of the volcanic cycles one by one with the astronomical periods one by one. According to the astronomical periods, volcanic eruptions may possibly be predicted in the future.

  1. Observatory Sponsoring Astronomical Image Contest

    Science.gov (United States)

    2005-05-01

    Forget the headphones you saw in the Warner Brothers thriller Contact, as well as the guttural throbs emanating from loudspeakers at the Very Large Array in that 1997 movie. In real life, radio telescopes aren't used for "listening" to anything - just like visible-light telescopes, they are used primarily to make images of astronomical objects. Now, the National Radio Astronomy Observatory (NRAO) wants to encourage astronomers to use radio-telescope data to make truly compelling images, and is offering cash prizes to winners of a new image contest. Radio Galaxy Fornax A Radio Galaxy Fornax A Radio-optical composite image of giant elliptical galaxy NGC 1316, showing the galaxy (center), a smaller companion galaxy being cannibalized by NGC 1316, and the resulting "lobes" (orange) of radio emission caused by jets of particles spewed from the core of the giant galaxy Click on image for more detail and images CREDIT: Fomalont et al., NRAO/AUI/NSF "Astronomy is a very visual science, and our radio telescopes are capable of producing excellent images. We're sponsoring this contest to encourage astronomers to make the extra effort to turn good images into truly spectacular ones," said NRAO Director Fred K.Y. Lo. The contest, offering a grand prize of $1,000, was announced at the American Astronomical Society's meeting in Minneapolis, Minnesota. The image contest is part of a broader NRAO effort to make radio astronomical data and images easily accessible and widely available to scientists, students, teachers, the general public, news media and science-education professionals. That effort includes an expanded image gallery on the observatory's Web site. "We're not only adding new radio-astronomy images to our online gallery, but we're also improving the organization and accessibility of the images," said Mark Adams, head of education and public outreach (EPO) at NRAO. "Our long-term goal is to make the NRAO Image Gallery an international resource for radio astronomy imagery

  2. Astronomical Signatures of Dark Matter

    OpenAIRE

    Paul Gorenstein; Wallace Tucker

    2014-01-01

    Several independent astronomical observations in different wavelength bands reveal the existence of much larger quantities of matter than what we would deduce from assuming a solar mass to light ratio. They are very high velocities of individual galaxies within clusters of galaxies, higher than expected rotation rates of stars in the outer regions of galaxies, 21 cm line studies indicative of increasing mass to light ratios with radius in the halos of spiral galaxies, hot gaseous X-ray emitti...

  3. Euler: Genius Blind Astronomer Mathematician

    OpenAIRE

    Musielak, Dora

    2014-01-01

    Leonhard Euler, the most prolific mathematician in history, contributed to advance a wide spectrum of topics in celestial mechanics. At the Saint Petersburg Observatory, Euler observed sunspots and tracked the movements of the Moon. Combining astronomical observations with his own mathematical genius, he determined the orbits of planets and comets. Euler laid the foundations of the methods of planetary perturbations and solved many of the Newtonian mechanics problems of the eighteenth century...

  4. Armenian Astronomical Society Annual Activities in 2014

    Science.gov (United States)

    Mickaelian, A. M.

    2015-07-01

    A report is given on the achievements of the Armenian astronomy during the last year and on the present activities of the Armenian Astronomical Society (ArAS). ArAS membership, ArAS electronic newsletters (ArASNews), ArAS webpage, annual meetings, Annual Prize for Young Astronomers (Yervant Terzian Prize) and other awards, international relations, presence in international organizations, summer schools, astronomical Olympiads and other events, matters related to astronomical education, astronomical heritage, astronomy outreach and ArAS further projects are discussed. The present meeting, BAO Science Camp, ArAS School lectures are among 2014 events as well.

  5. Conceptual approach to astronomical problems

    Science.gov (United States)

    Skvortsov, N. A.; Avvakumova, E. A.; Bryukhov, D. O.; Vovchenko, A. E.; Vol'nova, A. A.; Dluzhnevskaya, O. B.; Kaigorodov, P. V.; Kalinichenko, L. A.; Kniazev, A. Yu.; Kovaleva, D. A.; Malkov, O. Yu.; Pozanenko, A. S.; Stupnikov, S. A.

    2016-01-01

    New technical capabilities have brought about the sweeping growth of the amount of data acquired by the astronomers from observations with different instruments in various parts of the electromagnetic spectrum. We consider conceptual approach to be a promising tool to efficiently deal with these data. It uses problem domain knowledge to formulate the tasks and develop problem-solving algorithms and data analysis methods in terms of domain concepts without reference to particular data sources, and thereby allows solving certain problems in general form. We demonstrate the benefits of conceptual approach by using it to solve problems related to search for secondary photometric standard candidates, determination of galaxy redshifts, creation of a binary and multiple star repository based on inhomogeneous databases, and classification of eclipsing binaries.We formulate and solve these problems over specifications of astronomical knowledge units such as photometric systems, astronomical objects, multiple stars, etc., and define them in terms of the corresponding problem domains independently of the existing data resources.

  6. Developments in simulations and software for a near-infrared precision radial velocity spectrograph

    Science.gov (United States)

    Terrien, Ryan C.; Bender, Chad F.; Mahadevan, Suvrath; Halverson, Samuel P.; Ramsey, Lawrence W.; Hearty, Frederick R.

    2014-07-01

    We present developments in simulations and software for the Habitable Zone Planet Finder (HPF), an R~50,000 near-infrared cross-dispersed radial velocity spectrograph that will be used to search for planets around M dwarfs. HPF is fiber-fed, operates in the zYJ bands, and uses a 1.7μm cutoff HAWAII-2RG (H2RG) NIR detector. We have constructed an end-to-end simulator that accepts as input a range of stellar models contaminated with telluric features and processes these through a simulated detector. This simulator accounts for the characteristics of the H2RG, including interpixel capacitance, persistence, nonlinearities, read noise, and other detector characteristics, as measured from our engineering-grade H2RG. It also implements realistic order curvature. We describe applications of this simulator including optimization of the fiber configuration at the spectrograph slit and selection of properties for a laser frequency comb calibration source. The simulator has also provided test images for development of the HPF survey extraction and RV analysis pipeline and we describe progress on this pipeline itself, which will implement optimal extraction, laser frequency comb and emission lamp wavelength calibration, and cross-correlation based RV measurement.

  7. Constraining the age of the Matuyama-Brunhes reversal using intercalibrated 40Ar/39Ar and astronomical ages of the Bishop Tuff and Australasian Tektite

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Storey, Michael; Palike, Heiko;

    ). However, this age offset is not synchronous with a new astronomically intercalibrated 40Ar/39Ar age for the normal-polarity Quaternary Bishop Tuff, stratigraphically above the MB boundary by approximately 15 ka. In order to best constrain the age of the boundary, an astronomically calibrated radio...

  8. The Interface Region Imaging Spectrograph (IRIS)

    Science.gov (United States)

    De Pontieu, B.; Title, A. M.; Lemen, J. R.; Kushner, G. D.; Akin, D. J.; Allard, B.; Berger, T.; Boerner, P.; Cheung, M.; Chou, C.; Drake, J. F.; Duncan, D. W.; Freeland, S.; Heyman, G. F.; Hoffman, C.; Hurlburt, N. E.; Lindgren, R. W.; Mathur, D.; Rehse, R.; Sabolish, D.; Seguin, R.; Schrijver, C. J.; Tarbell, T. D.; Wülser, J.-P.; Wolfson, C. J.; Yanari, C.; Mudge, J.; Nguyen-Phuc, N.; Timmons, R.; van Bezooijen, R.; Weingrod, I.; Brookner, R.; Butcher, G.; Dougherty, B.; Eder, J.; Knagenhjelm, V.; Larsen, S.; Mansir, D.; Phan, L.; Boyle, P.; Cheimets, P. N.; DeLuca, E. E.; Golub, L.; Gates, R.; Hertz, E.; McKillop, S.; Park, S.; Perry, T.; Podgorski, W. A.; Reeves, K.; Saar, S.; Testa, P.; Tian, H.; Weber, M.; Dunn, C.; Eccles, S.; Jaeggli, S. A.; Kankelborg, C. C.; Mashburn, K.; Pust, N.; Springer, L.; Carvalho, R.; Kleint, L.; Marmie, J.; Mazmanian, E.; Pereira, T. M. D.; Sawyer, S.; Strong, J.; Worden, S. P.; Carlsson, M.; Hansteen, V. H.; Leenaarts, J.; Wiesmann, M.; Aloise, J.; Chu, K.-C.; Bush, R. I.; Scherrer, P. H.; Brekke, P.; Martinez-Sykora, J.; Lites, B. W.; McIntosh, S. W.; Uitenbroek, H.; Okamoto, T. J.; Gummin, M. A.; Auker, G.; Jerram, P.; Pool, P.; Waltham, N.

    2014-07-01

    The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33 - 0.4 arcsec spatial resolution, two-second temporal resolution, and 1 km s-1 velocity resolution over a field-of-view of up to 175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332 - 1358 Å, 1389 - 1407 Å, and 2783 - 2834 Å, including bright spectral lines formed in the chromosphere (Mg ii h 2803 Å and Mg ii k 2796 Å) and transition region (C ii 1334/1335 Å and Si iv 1394/1403 Å). Slit-jaw images in four different passbands (C ii 1330, Si iv 1400, Mg ii k 2796, and Mg ii wing 2830 Å) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec × 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative-MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.

  9. First Visiting Astronomers at VLT KUEYEN

    Science.gov (United States)

    2000-04-01

    A Deep Look into the Universal Hall of Mirrors Starting in the evening of April 1, 2000, Ghislain Golse and Francisco Castander from the Observatoire Midi-Pyrénées (Toulouse, France) [1] were the first "visiting astronomers" at Paranal to carry out science observations with the second 8.2-m VLT Unit Telescope, KUEYEN . Using the FORS2 multi-mode instrument as a spectrograph, they measured the distances to a number of very remote galaxies, located far out in space behind two clusters of galaxies. Such observations may help to determine the values of cosmological parameters that define the geometry and fate of the Universe. After two nights of observations, the astronomers came away from Paranal with a rich harvest of data and a good feeling. "We are delighted that the telescope performed so well. It is really impressive how far out one can reach with the VLT, compared to the `smaller' 4-meter telescopes with which we previously observed. It opens a new window towards the distant, early Universe. Now we are eager to start reducing and analysing these data!" , Francisco Castander said. Measuring the Geometry of the Universe with Multiple Images in Cluster Lenses The present programme is typical of the fundamental cosmological studies that are now being undertaken with the ESO Very Large Telescope (VLT). Clusters of galaxies are very massive objects. Their gravitational fields intensify ("magnify") and distort the images of galaxies behind them. The magnification factor for the faint background galaxy population seen within a few arcminutes of the centre of a massive cluster at intermediate distance (redshift z ~ 0.2 - 0.4, i.e., corresponding to a look-back time of approx. 2 - 4 billion years) is typically larger than 2, and occasionally much larger. The clusters thus function as gravitational lenses . They may be regarded as "natural telescopes" that help us to see fainter objects further out into space than would otherwise be possible with our own telescopes. In a

  10. Interstellar Medium Absorption Profile Spectrograph (IMAPS)

    Science.gov (United States)

    Jenkins, E. B.

    1985-08-01

    The design and fabrication of an objective-grating echelle spectrograph to fly on sounding rockets and record spectra of stars from approximately 920 to 1120A with a resolving power lambda/delta lambda = 200,000 is discussed. The scientific purpose of the program is to observe, with ten times better velocity resolution than before, the plentiful absorption lines in this spectral region produced by atoms, ions and molecules in the interstellar medium. In addition, an important technical goal is to develop and flight-quality a new ultraviolet, photon-counting image sensor which has a windowless, opaque photocathode and a CCD bombarded directly by the accelerated photoelectrons. Except for some initial difficulties with the performance of CCDs, the development of the payload instrument is relatively straightforward and our overall design goals are satisfied. The first flight occurred in late 1984, but no data were obtained because of an inrush of air degraded the instrument's vacuum and caused the detector's high voltage to arc. A second flight in early 1985 was a complete success and obtained a spectrum of pi Sco. Data from this mission are currently being reduced; quick-look versions of the spectra indicate that excellent results will be obtained. Currently, the payload is being reconfigured to fly on a Spartan mission in 1988.

  11. Herschel SPIRE FTS Relative Spectral Response Calibration

    CERN Document Server

    Fulton, Trevor; Baluteau, Jean-Paul; Benielli, Dominique; Imhof, Peter; Lim, Tanya; Lu, Nanyao; Marchili, Nicola; Naylor, David; Polehampton, Edward; Swinyard, Bruce; Valtchanov, Ivan

    2014-01-01

    Herschel/SPIRE Fourier transform spectrometer (FTS) observations contain emission from both the Herschel Telescope and the SPIRE Instrument itself, both of which are typically orders of magnitude greater than the emission from the astronomical source, and must be removed in order to recover the source spectrum. The effects of the Herschel Telescope and the SPIRE Instrument are removed during data reduction using relative spectral response calibration curves and emission models. We present the evolution of the methods used to derive the relative spectral response calibration curves for the SPIRE FTS. The relationship between the calibration curves and the ultimate sensitivity of calibrated SPIRE FTS data is discussed and the results from the derivation methods are compared. These comparisons show that the latest derivation methods result in calibration curves that impart a factor of between 2 and 100 less noise to the overall error budget, which results in calibrated spectra for individual observations whose n...

  12. Astronomical measurement a concise guide

    CERN Document Server

    Lawrence, Andy

    2014-01-01

    This book on astronomical measurement takes a fresh approach to teaching the subject. After discussing some general principles, it follows the chain of measurement through atmosphere, imaging, detection, spectroscopy, timing, and hypothesis testing. The various wavelength regimes are covered in each section, emphasising what is the same, and what is different. The author concentrates on the physics of detection and the principles of measurement, aiming to make this logically coherent. The book is based on a short self contained lecture course for advanced undergraduate students developed and taught by the author over several years.

  13. Visualizing Astronomical Data with Blender

    Science.gov (United States)

    Kent, Brian R.

    2014-01-01

    We present methods for using the 3D graphics program Blender in the visualization of astronomical data. The software's forte for animating 3D data lends itself well to use in astronomy. The Blender graphical user interface and Python scripting capabilities can be utilized in the generation of models for data cubes, catalogs, simulations, and surface maps. We review methods for data import, 2D and 3D voxel texture applications, animations, camera movement, and composite renders. Rendering times can be improved by using graphic processing units (GPUs). A number of examples are shown using the software features most applicable to various kinds of data paradigms in astronomy.

  14. Focus on astronomical predictable events

    DEFF Research Database (Denmark)

    Jacobsen, Aase Roland

    2006-01-01

    At the Steno Museum Planetarium we have for many occasions used a countdown clock to get focus om astronomical events. A countdown clock can provide actuality to predictable events, for example The Venus Transit, Opportunity landing on Mars and The Solar Eclipse. The movement of the clock attracs...... the public and makes a point of interest in a small exhibit area. A countdown clock can be simple, but it is possible to expand the concept to an eye-catching part of a museum....

  15. Formation flight astronomical survey telescope

    Science.gov (United States)

    Tsunemi, Hiroshi

    2012-03-01

    Formation Flight Astronomical Survey Telescope (FFAST) is a project for hard X-ray observation. It consists of two small satellites; one (telescope satellite) has a super mirror covering the energy range up to 80 keV while the other (detector satellite) has an scintillator deposited CCD (SDCCD) having good spatial resolution and high efficiency up to 100 keV. Two satellites will be put into individual Kepler orbits forming an X-ray telescope with a focal length of 20 m. They will be not in pointing mode but in survey mode to cover a large sky region.

  16. astroplan: Observation Planning for Astronomers

    Science.gov (United States)

    Morris, Brett

    2016-03-01

    Astroplan is an observation planning package for astronomers. It is an astropy-affiliated package which began as a Google Summer of Code project. Astroplan facilitates convenient calculation of common observational quantities, like target altitudes and azimuths, airmasses, and rise/set times. Astroplan also computes when targets are observable given various extensible observing constraints, for example: within a range of airmasses or altitudes, or at a given separation from the Moon. Astroplan is taught in the undergraduate programming for astronomy class, and enables observational Pre- MAP projects at the University of Washington. In the near future, we plan to implement scheduling capabilities in astroplan on top of the constraints framework.

  17. Explanatory supplement to the astronomical almanac

    CERN Document Server

    Urban, Sean E

    2013-01-01

    The Explanatory Supplement to the Astronomical Almanac offers explanatory material, supplemental information and detailed descriptions of the computational models and algorithms used to produce The Astronomical Almanac, which is an annual publication prepared jointly by the US Naval Observatory and Her Majesty's Nautical Almanac Office in the UK. Like The Astronomical Almanac, The Explanatory Supplement provides detailed coverage of modern positional astronomy. Chapters are devoted to the celestial and terrestrial reference frames, orbital ephemerides, precession, nutation, Earth rotation, and coordinate transformations. These topics have undergone substantial revisions since the last edition was published. Astronomical positions are intertwined with timescales and relativity in The Astronomical Almanac, so related chapters are provided in The Explanatory Supplement. The Astronomical Almanac also includes information on lunar and solar eclipses, physical ephemerides of solar system bodies, and calendars, so T...

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

    CERN Document Server

    Sugai, Hajime; 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; Vilaça, Rodrigo de Paiva; Partos, Eamon J; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J; Riddle, Reed; Santos, Leandro; Santos, Jesulino Bispo dos; 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

    2015-01-01

    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 {\\mu}m to 1.26 {\\mu}m, 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 {\\mu}m to 0.89 {\\mu}m 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 ...

  19. AAOmega: a multipurpose fiber-fed spectrograph for the AAT

    Science.gov (United States)

    Smith, Greg A.; Saunders, Will; Bridges, Terry; Churilov, Vladimir; Lankshear, Allan; Dawson, John; Correll, David; Waller, Lew; Haynes, Roger; Frost, Gabriella

    2004-09-01

    The AAOmega project replaces the two 2dF spectrographs, which are mounted on the top end of the Anglo Australian Telescope, with a bench mounted double beam spectrograph covering 370 to 950nm. The 2dF positioner, field plate tumbler mechanism, and fiber retractors will be retained. The new spectrograph will be fed by 392 fibers from either of the two 2dF field plates, or by the 512 fiber Spiral integral field unit, located at the Cassegrain focus. New instrument control electronics has also been designed to drive the spectrograph. Stability will be improved by locating the spectrograph off the telescope, but the 2df fibers must be extended to thirty-eight metres length. Despite this, using fibers with improved characteristics, increased pupil diameter, volume phase holographic (VPH) gratings with articulated cameras, and more efficient coatings on optics we achieve a minimum twofold increase in throughput. We will also fit larger (4k x 2k pixel) detectors. The spectrograph comprises: a F/3.15 Schmidt collimator, incorporating a dichroic beamsplitter; interchangeable VPH gratings; and articulating red and blue F/1.3 Schmidt cameras. The beamsplitter may be exchanged with others which cut off at different wavelengths. A full suite of VPH gratings are provided to cover resolution to 8000.

  20. The Infrared Astronomical Mission AKARI

    CERN Document Server

    Murakami, H; Barthel, P; Clements, D L; Cohen, M; Doi, Y; Enya, K; Figueredo, E; Fujishiro, N; Fujiwara, H; Fujiwara, M; García-Lario, P; Goto, T; Hasegawa, S; Hibi, Y; Hirao, T; Hiromoto, N; Hong, S S; Imai, K; Ishigaki, M; Ishiguro, M; Ishihara, D; Ita, Y; Jeong, W -S; Jeong, K S; Kaneda, H; Kataza, H; Kawada, M; Kawai, T; Kawamura, A; Kessler, M F; Kester, Do; Kii, T; Kim, D C; Kim, W; Kobayashi, H; Koo, B C; Kwon, S M; Lee, H M; Lorente, R; Makiuti, S; Matsuhara, H; Matsumoto, T; Matsuo, H; Matsuura, S; Müller, T G; Murakami, N; Nagata, H; Nakagawa, T; Naoi, T; Narita, M; Noda, M; Oh, S H; Ohnishi, A; Ohyama, Y; Okada, Y; Okuda, H; Oliver, S; Onaka, T; Ootsubo, T; Oyabu, S; Pak, S; Park, Y S; Pearson, C P; Rowan-Robinson, M; Saitô, T; Sakon, I; Salama, A; Sato, S; Savage, R S; Serjeant, S; Shibai, H; Shirahata, M; Sohn, J J; Suzuki, T; Takagi, T; Takahashi, H; Tanabé, T; Takeuchi, T T; Takita, S; Thomson, M; Uemizu, K; Ueno, M; Usui, F; Verdugo, E; Wada, T; Wang, L; Watabe, T; Watarai, H; White, G J; Yamamura, I; Yamauchi, C; Yasuda, A

    2007-01-01

    AKARI, the first Japanese satellite dedicated to infrared astronomy, was launched on 2006 February 21, and started observations in May of the same year. AKARI has a 68.5 cm cooled telescope, together with two focal-plane instruments, which survey the sky in six wavelength bands from the mid- to far-infrared. The instruments also have the capability for imaging and spectroscopy in the wavelength range 2 - 180 micron in the pointed observation mode, occasionally inserted into the continuous survey operation. The in-orbit cryogen lifetime is expected to be one and a half years. The All-Sky Survey will cover more than 90 percent of the whole sky with higher spatial resolution and wider wavelength coverage than that of the previous IRAS all-sky survey. Point source catalogues of the All-Sky Survey will be released to the astronomical community. The pointed observations will be used for deep surveys of selected sky areas and systematic observations of important astronomical targets. These will become an additional ...

  1. Processing Color in Astronomical Imagery

    CERN Document Server

    Arcand, Kimberly K; Rector, Travis; Levay, Zoltan G; DePasquale, Joseph; Smarr, Olivia

    2013-01-01

    Every year, hundreds of images from telescopes on the ground and in space are released to the public, making their way into popular culture through everything from computer screens to postage stamps. These images span the entire electromagnetic spectrum from radio waves to infrared light to X-rays and gamma rays, a majority of which is undetectable to the human eye without technology. Once these data are collected, one or more specialists must process the data to create an image. Therefore, the creation of astronomical imagery involves a series of choices. How do these choices affect the comprehension of the science behind the images? What is the best way to represent data to a non-expert? Should these choices be based on aesthetics, scientific veracity, or is it possible to satisfy both? This paper reviews just one choice out of the many made by astronomical image processors: color. The choice of color is one of the most fundamental when creating an image taken with modern telescopes. We briefly explore the ...

  2. LGBT Workplace Issues for Astronomers

    Science.gov (United States)

    Kay, Laura E.; Danner, R.; Sellgren, K.; Dixon, V.; GLBTQastro

    2011-01-01

    Federal Equal Employment Opportunity laws and regulations do not provide protection from discrimination on the basis of sexual orientation or gender identity or gender expression. Sexual minority astronomers (including lesbian, gay, bisexual and transgender people; LGBT) can face additional challenges at school and work. Studies show that LGBT students on many campuses report experiences of harassment. Cities, counties, and states may or may not have statutes to protect against such discrimination. There is wide variation in how states and insurance plans handle legal and medical issues for transgender people. Federal law does not acknowledge same-sex partners, including those legally married in the U.S. or in other countries. Immigration rules in the U.S. (and many other, but not all) countries do not recognize same-sex partners for visas, employment, etc. State `defense of marriage act' laws have been used to remove existing domestic partner benefits at some institutions, or benefits can disappear with a change in governor. LGBT astronomers who change schools, institutions, or countries during their career may experience significant differences in their legal, medical, and marital status.

  3. Astronomers in the Chemist's War

    Science.gov (United States)

    Trimble, Virginia L.

    2012-01-01

    World War II, with radar, rockets, and "atomic" bombs was the physicists' war. And many of us know, or think we know, what our more senior colleagues did during it, with Hubble and Hoffleit at Aberdeen; M. Schwarzschild on active duty in Italy; Bondi, Gold, and Hoyle hunkered down in Dunsfeld, Surrey, talking about radar, and perhaps steady state; Greenstein and Henyey designing all-sky cameras; and many astronomers teaching navigation. World War I was The Chemists' War, featuring poison gases, the need to produce liquid fuels from coal on one side of the English Channel and to replace previously-imported dyesstuffs on the other. The talke will focus on what astronomers did and had done to them between 1914 and 1919, from Freundlich (taken prisoner on an eclipse expedition days after the outbreak of hostilities) to Edwin Hubble, returning from France without ever having quite reached the front lines. Other events bore richer fruit (Hale and the National Research Council), but very few of the stories are happy ones. Most of us have neither first nor second hand memories of The Chemists' War, but I had the pleasure of dining with a former Freundlich student a couple of weeks ago.

  4. Astronomical Signatures of Dark Matter

    Directory of Open Access Journals (Sweden)

    Paul Gorenstein

    2014-01-01

    Full Text Available Several independent astronomical observations in different wavelength bands reveal the existence of much larger quantities of matter than what we would deduce from assuming a solar mass to light ratio. They are very high velocities of individual galaxies within clusters of galaxies, higher than expected rotation rates of stars in the outer regions of galaxies, 21 cm line studies indicative of increasing mass to light ratios with radius in the halos of spiral galaxies, hot gaseous X-ray emitting halos around many elliptical galaxies, and clusters of galaxies requiring a much larger component of unseen mass for the hot gas to be bound. The level of gravitational attraction needed for the spatial distribution of galaxies to evolve from the small perturbations implied by the very slightly anisotropic cosmic microwave background radiation to its current web-like configuration requires much more mass than is observed across the entire electromagnetic spectrum. Distorted shapes of galaxies and other features created by gravitational lensing in the images of many astronomical objects require an amount of dark matter consistent with other estimates. The unambiguous detection of dark matter and more recently evidence for dark energy has positioned astronomy at the frontier of fundamental physics as it was in the 17th century.

  5. First Light with ALES: A 2-5 Micron Adaptive Optics Integral Field Spectrograph for the LBT

    CERN Document Server

    Skemer, Andrew J; Montoya, Manny; Skrutskie, Michael F; Leisenring, Jarron; Durney, Oli; Woodward, Charles E; Wilson, John; Nelson, Matt; Bailey, Vanessa; Defrere, Denis; Stone, Jordan

    2015-01-01

    Integral field spectrographs are an important technology for exoplanet imaging, due to their ability to take spectra in a high-contrast environment, and improve planet detection sensitivity through spectral differential imaging. ALES is the first integral field spectrograph capable of imaging exoplanets from 3-5$\\mu$m, and will extend our ability to characterize self-luminous exoplanets into a wavelength range where they peak in brightness. ALES is installed inside LBTI/LMIRcam on the Large Binocular Telescope, taking advantage of existing AO systems, camera optics, and a HAWAII-2RG detector. The new optics that comprise ALES are a Keplerian magnifier, a silicon lenslet array with diffraction suppressing pinholes, a direct vision prism, and calibration optics. All of these components are installed in filter wheels making ALES a completely modular design. ALES saw first light at the LBT in June 2015.

  6. Calibration uncertainty

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Anglov, Thomas

    2002-01-01

    uncertainty was verified from independent measurements of the same sample by demonstrating statistical control of analytical results and the absence of bias. The proposed method takes into account uncertainties of the measurement, as well as of the amount of calibrant. It is applicable to all types......Methods recommended by the International Standardization Organisation and Eurachem are not satisfactory for the correct estimation of calibration uncertainty. A novel approach is introduced and tested on actual calibration data for the determination of Pb by ICP-AES. The improved calibration...

  7. Astronomical Symbolism in Australian Aboriginal Rock Art

    CERN Document Server

    Norris, Ray P

    2010-01-01

    Traditional Aboriginal Australian cultures include a significant astronomical component, perpetuated through oral tradition and ceremony. This knowledge has practical navigational and calendrical functions, and sometimes extends to a deep understanding of the motion of objects in the sky. Here we explore whether this astronomical tradition is reflected in the rock art of Aboriginal Australians. We find several plausible examples of depictions of astronomical figures and symbols, and also evidence that astronomical observations were used to set out stone arrangements. However, we recognise that the case is not yet strong enough to make an unequivocal statement, and describe our plans for further research.

  8. HEIDI: An Automated Process for the Identification and Extraction of Photometric Light Curves from Astronomical Images

    CERN Document Server

    Todd, M; Tanga, P; Coward, D M; Zadnik, M G

    2014-01-01

    The production of photometric light curves from astronomical images is a very time-consuming task. Larger data sets improve the resolution of the light curve, however, the time requirement scales with data volume. The data analysis is often made more difficult by factors such as a lack of suitable calibration sources and the need to correct for variations in observing conditions from one image to another. Often these variations are unpredictable and corrections are based on experience and intuition. The High Efficiency Image Detection & Identification (HEIDI) pipeline software rapidly processes sets of astronomical images. HEIDI automatically selects multiple sources for calibrating the images using an algorithm that provides a reliable means of correcting for variations between images in a time series. The algorithm takes into account that some sources may intrinsically vary on short time scales and excludes these from being used as calibration sources. HEIDI processes a set of images from an entire nigh...

  9. Ticking Stellar Time Bomb Identified - Astronomers find prime suspect for a Type Ia supernova

    Science.gov (United States)

    2009-11-01

    it will eventually become heavy enough to explode as a supernova. Combining the NACO images with data obtained with several other telescopes [5] the astronomers could determine the distance of the system - about 25 000 light-years from the Sun - and its intrinsic brightness - over 10 000 times brighter than the Sun. This implies that the vampire white dwarf in this system has a high mass that is near its fatal limit and is still simultaneously being fed by its companion at a high rate. "Whether V445 Puppis will eventually explode as a supernova, or if the current nova outburst has pre-empted that pathway by ejecting too much matter back into space is still unclear," says Woudt. "But we have here a pretty good suspect for a future Type Ia supernova!" Notes [1] White dwarfs represent the evolutionary end product of stars with initial masses up to a few solar masses. A white dwarf is the burnt-out stellar core that is left behind when a star like the Sun sheds its outer layers towards the end of its active life. It is composed essentially of carbon and oxygen. This process normally also leads to the formation of a surrounding planetary nebula. [2] Adaptive optics is a technique that allows astronomers to obtain an image of an object free from the blurring effect of the atmosphere. See the adaptive optics page at ESO: http://www.eso.org/public/astronomy/technology/adaptive_optics.html [3] See for example http://www.eso.org/~bleibund/papers/EPN/epn.html [4] This Chandrasekhar limit, named after the Indian physicist Subrahmanyan Chandrasekhar, is nearly 1.4 times the mass of the Sun. When a white dwarf reaches a mass above this limit, either by sucking matter from a companion or merging with another white dwarf, it will turn itself into a thermonuclear bomb that will burn carbon and oxygen explosively. [5] The team also used the SOFI instrument on ESO's New Technology Telescope, the IMACS spectrograph on the 6.5-metre Magellan Baade telescope, and the Infrared Survey

  10. The Mitchell Spectrograph: Studying Nearby Galaxies with the VIRUS Prototype

    Directory of Open Access Journals (Sweden)

    Guillermo A. Blanc

    2013-01-01

    Full Text Available The Mitchell Spectrograph (a.k.a. VIRUS-P on the 2.7 m Harlan J. Smith telescope at McDonald Observatory is currently the largest field of view (FOV integral field unit (IFU spectrograph in the world (1.7′×1.7′. It was designed as a prototype for the highly replicable VIRUS spectrograph which consists of a mosaic of IFUs spread over a 16′ diameter FOV feeding 150 spectrographs similar to the Mitchell. VIRUS will be deployed on the 9.2 meter Hobby-Eberly Telescope (HET and will be used to conduct the HET Dark Energy Experiment (HETDEX. Since seeing first light in 2007 the Mitchell Spectrograph has been widely used, among other things, to study nearby galaxies in the local universe where their internal structure and the spatial distribution of different physical parameters can be studied in great detail. These observations have provided important insight into many aspects of the physics behind the formation and evolution of galaxies and have boosted the scientific impact of the 2.7 meter telescope enormously. Here I review the contributions of the Mitchell Spectrograph to the study of nearby galaxies, from the investigation the spatial distribution of dark matter and the properties of supermassive black holes, to the studies of the process of star formation and the chemical composition of stars and gas in the ISM, which provide important information regarding the formation and evolution of these systems. I highlight the fact that wide field integral field spectrographs on small and medium size telescopes can be powerful cost effective tools to study the astrophysics of galaxies. Finally I briefly discuss the potential of HETDEX for conducting studies on nearby galaxies. The survey parameters make it complimentary and competitive to ongoing and future surveys like SAMI and MANGA.

  11. Christopher Clavius astronomer and mathematician

    CERN Document Server

    Sigismondi, Costantino

    2012-01-01

    The Jesuit scientist Christopher Clavius (1538-1612) has been the most influential teacher of the renaissance. His contributions to algebra, geometry, astronomy and cartography are enormous. He paved the way, with his texts and his teaching for 40 years in the the Collegio Romano, to the development of these sciences and their fruitful spread all around the World, along the commercial paths of Portugal, which become also the missionary paths for the Jesuits. The books of Clavius were translated into Chinese, by one of his students Matteo Ricci "Li Madou" (1562-1610), and his influence for the development of science in China was crucial. The Jesuits become skilled astronomers, cartographers and mathematicians thanks to the example and the impulse given by Clavius. This success was possible also thanks to the contribution of Clavius in the definition of the Ratio Studiorum, the program of studies, in the Jesuit colleges, so influential for the whole history of modern Europe and all western World.

  12. IAU Public Astronomical Organisations Network

    Science.gov (United States)

    Canas, Lina; Cheung, Sze Leung

    2015-08-01

    The Office for Astronomy Outreach has devoted intensive means to create and support a global network of public astronomical organisations around the world. Focused on bringing established and newly formed amateur astronomy organizations together, providing communications channels and platforms for disseminating news to the global community and the sharing of best practices and resources among these associations around the world. In establishing the importance that these organizations have for the dissemination of activities globally and acting as key participants in IAU various campaigns social media has played a key role in keeping this network engaged and connected. Here we discuss the implementation process of maintaining this extensive network, the processing and gathering of information and the interactions between local active members at a national and international level.

  13. Ancient Astronomical Monuments of Athens

    Science.gov (United States)

    Theodossiou, E.; Manimanis, V. N.

    2010-07-01

    In this work, four ancient monuments of astronomical significance found in Athens and still kept in the same city in good condition are presented. The first one is the conical sundial on the southern slope of the Acropolis. The second one is the Tower of the Winds and its vertical sundials in the Roman Forum of Athens, a small octagonal marble tower with sundials on all 8 of its sides, plus a water-clock inside the tower. The third monument-instrument is the ancient clepsydra of Athens, one of the findings from the Ancient Agora of Athens, a unique water-clock dated from 400 B.C. Finally, the fourth one is the carved ancient Athenian calendar over the main entrance of the small Byzantine temple of the 8th Century, St. Eleftherios, located to the south of the temple of the Annunciation of Virgin Mary, the modern Cathedral of the city of Athens.

  14. Astronomical arguments in Newton's Chronology

    CERN Document Server

    Naze, Yael

    2012-01-01

    In his Chronology, Newton uses astronomical "evidence" to support its extreme rejuvenation of ancient times. These elements, having a scientific varnish, provide some credibility to the work. They have been fiercely debated for a century, with a gradual undermining of Newton's assumptions. However, this has not dented the prestige of the English scientist. ----- Dans sa Chronologie, Newton utilise des "preuves" astronomiques pour appuyer son rajeunissement extreme des epoques anciennes. Ces elements, au vernis scientifique, donnent une credibilite certaine a l'ensemble. Ils ont donc ete aprement discutes, les debats sapant petit a petit les hypotheses du savant anglais pour finalement porter un coup mortel a l'ensemble. Cela n'a toutefois pas entame le prestige du savant anglais.

  15. The PRL Stabilized High-Resolution Echelle Fiber-fed Spectrograph: Instrument Description and First Radial Velocity Results

    Science.gov (United States)

    Chakraborty, Abhijit; Mahadevan, Suvrath; Roy, Arpita; Dixit, Vaibhav; Richardson, Eric Harvey; Dongre, Varun; Pathan, F. M.; Chaturvedi, Priyanka; Shah, Vishal; Ubale, Girish P.; Anandarao, B. G.

    2014-02-01

    We present spectrograph design details and initial radial velocity results from the PRL optical fiber-fed high-resolution cross-dispersed echelle spectrograph (PARAS), which has recently been commissioned at the Mount Abu 1.2 m telescope in India. Data obtained as part of the postcommissioning tests with PARAS show velocity precision better than 2 m s-1 over a period of several months on bright RV standard stars. For observations of σ Dra, we report 1.7 m s-1 precision for a period of 7 months, and for HD 9407, we report 2.1 m s-1 over a period of 2 months. PARAS is capable of single-shot spectral coverage of 3800-9500 Å at a resolution of ~67,000. The RV results were obtained between 3800 and 6900 Å using simultaneous wavelength calibration with a thorium-argon (ThAr) hollow cathode lamp. The spectrograph is maintained under stable conditions of temperature with a precision of 0.01-0.02° C (rms) at 25.55° C and is enclosed in a vacuum vessel at pressure of 0.1 ± 0.03 mbar. The blaze peak efficiency of the spectrograph between 5000 and 6500 Å, including the detector, is ~30%; it is ~25% with the fiber transmission. The total efficiency, including spectrograph, fiber transmission, focal ratio degradation (FRD), and telescope (with 81% reflectivity) is ~7% in the same wavelength region on a clear night with good seeing conditions. The stable point-spread function (PSF), environmental control, existence of a simultaneous calibration fiber, and availability of observing time make PARAS attractive for a variety of exoplanetary and stellar astrophysics projects. Future plans include testing of octagonal fibers for further scrambling of light and extensive calibration over the entire wavelength range up to 9500 Å using thorium-neon (ThNe) or uranium-neon (UNe) spectral lamps. Thus, we demonstrate how such highly stabilized instruments, even on small aperture telescopes, can contribute significantly to the ongoing radial velocity searches for low-mass planets

  16. Balloon UV Experiments for Astronomical and Atmospheric Observations

    CERN Document Server

    Sreejith, A G; Sarpotdar, Mayuresh; Nirmal, K; Ambily, S; Prakash, Ajin; Safonova, Margarita; Murthy, Jayant

    2016-01-01

    The ultraviolet (UV) window has been largely unexplored through balloons for astronomy. We discuss here the development of a compact near-UV spectrograph with ?ber optics input for balloon ights. It is a modi?ed Czerny-Turner system built using o?-the-shelf components. The system is portable and scalable to di?erent telescopes. The use of re ecting optics reduces the transmission loss in the UV. It employs an image-intensi?ed CMOS sensor, operating in photon counting mode, as the detector of choice. A lightweight pointing system developed for stable pointing to observe astronomical sources is also discussed, together with the methods to improve its accuracy, e.g. using the in-house build star sensor and others. Our primary scienti?c objectives include the observation of bright Solar System objects such as visible to eye comets, Moon and planets. Studies of planets can give us valuable information about the planetary aurorae, helping to model and compare atmospheres of other planets and the Earth. The other ma...

  17. Novel Algorithms for Astronomical Plate Analyses

    Indian Academy of Sciences (India)

    Rene Hudec; Lukas Hudec

    2011-03-01

    Powerful computers and dedicated software allow effective data mining and scientific analyses in astronomical plate archives. We give and discuss examples of newly developed algorithms for astronomical plate analyses, e.g., searches for optical transients, as well as for major spectral and brightness changes.

  18. An introduction to the World Space Observatory-Ultraviolet spectrographs

    Science.gov (United States)

    Hermanutz, S.; Barnstedt, J.; Diebold, S.; Elsener, H. R.; Ganz, P. R.; Kalkuhl, C.; Kappelmann, N.; Pfeifer, M.; Tanirah, O.; Sachkov, M.; Schaadt, D. M.; Schanz, T.; Shustov, B. M.; Werner, K.

    2012-09-01

    The World Space Observatory Ultraviolet (WSO-UV) is a multinational mission under the leadership of Russia with contributions of Spain and Germany. The mission is part of the Spektrum series and launch is currently scheduled for 2016. It consists of a 1.7m mirror focusing on spectrographs in the range of 102-310 nm withh a resolution of R >= 55,000 for high resolution spectral observations, a long-slit-spectrograph for spatially resolved observations and an imager. According to the Phase-B-Study all spectrographs will use the same detectors built by the IAAT. These spectrographs are designed to observe cosmic plasma with temperatures of several ten thousands Kelvin and atomic transition lines of all important atoms and molecuules like H2, CO, OH eetc. In knowledge about the formation of galaxies and analyze the atmospheres of extrasolar planets and protoplanetary discs. To achieve these goals the IAAT designed in cooperation with the Leibniz-Institute for Analytical Sciences (ISAS Berlin) the spectrographs. In addition Tubingen develops and builds a new type of michrchannel plate detector based on gallim nitride cathods and a cross-strip-anode.

  19. The Mitchell Spectrograph: Studying Nearby Galaxies with the VIRUS Prototype

    CERN Document Server

    Blanc, Guillermo A

    2014-01-01

    The Mitchell Spectrograph (a.k.a. VIRUS-P) on the 2.7m Harlan J. Smith telescope at McDonald Observatory is currently the largest field of view (FOV) integral field unit (IFU) spectrograph in the world (1.7'x1.7'). It was designed as a prototype for the highly replicable VIRUS spectrograph which consists of a mosaic of IFUs spread over a 16' diameter FOV feeding 150 spectrographs similar to the Mitchell. VIRUS will be deployed on the 9.2 meter Hobby-Eberly Telescope (HET) and will be used to conduct the HET Dark Energy Experiment (HETDEX). Since seeing first light in 2007 the Mitchell Spectrograph has been widely used, among other things, to study nearby galaxies in the local universe where their internal structure and the spatial distribution of different physical parameters can be studied in great detail. These observations have provided important insight into many aspects of the physics behind the formation and evolution of galaxies and have boosted the scientific impact of the 2.7 meter telescope enormous...

  20. Construction of pre-slit system of Chinese SONG spectrograph

    Science.gov (United States)

    Gao, Pengfei; Hu, Zhongwen; Dai, Songxin

    2015-10-01

    The pre-slit system of Chinese SONG spectrograph is a multi-function unit. The main function is to direct the incoming light from the coudé path to the entrance slit of the spectrograph. The specific functions includes maintaining exit pupil stable, fast guiding and telescope focus corrections. The original optics of this pre-slit system were designed by Aarhus University in Denmark. We built the system and designed the software for it. This system holds a guide/slit-viewing camera, a pupil-viewing camera, two tip-tilt mirrors and its tip-tilt controllers. So it includes two sets of the fast-steering mirror systems applied to image tracking and correction. When this image tracking and correction systems is running, the real-time software algorithm will be presented and simulated simultaneously. From the images taken with camera, a closed loop signals are generated for the tip-tilt mirror to correct image motion. When the camera exposure time is 25ms,the correcting frequency of slit imge tip-tilt motion is about 30Hz. The correcting frequency of pupil imge tip-tilt motion is about 1Hz. In addition, a temperature control system surrounding the spectrograph is necessary to keep spectrograph at a constant temperature. The test results shows that the error is about +/-0.005°C in 69.4 hours. The results prove that the pre-slit system of Chinese SONG spectrograph is effective and feasible.

  1. Learning from history: Adaptive calibration of 'tilting spine' fiber positioners

    CERN Document Server

    Gilbert, James

    2015-01-01

    This paper discusses a new approach for determining the calibration parameters of independently-actuated optical fibers in multi-object astronomical fiber positioning systems. This work comes from the development of a new type of piezoelectric motor intended to enhance the 'tilting spine' fiber positioning technology originally created by the Australian Astronomical Observatory. Testing has shown that the motor's performance can vary depending on the fiber's location within its accessible field, meaning that an individual fiber is difficult calibrate with a one-time routine. Better performance has resulted from constantly updating calibration parameters based on the observed movements of the fiber during normal closed-loop positioning. Over time, location-specific historical data is amassed that can be used to better predict the results of a future fiber movement. This is similar to a technique previously proposed by the Australian Astronomical Observatory, but with the addition of location-specific learning....

  2. Volume phase holographic gratings for the Subaru Prime Focus Spectrograph: performance measurements of the prototype grating set

    Science.gov (United States)

    Barkhouser, Robert H.; Arns, James; Gunn, James E.

    2014-08-01

    The Prime Focus Spectrograph (PFS) is a major instrument under development for the 8.2 m Subaru telescope on Mauna Kea. Four identical, fixed spectrograph modules are located in a room above one Nasmyth focus. A 55 m fiber optic cable feeds light into the spectrographs from a robotic fiber positioner mounted at the telescope prime focus, behind the wide field corrector developed for Hyper Suprime-Cam. The positioner contains 2400 fibers and covers a 1.3 degree hexagonal field of view. Each spectrograph module will be capable of simultaneously acquiring 600 spectra. The spectrograph optical design consists of a Schmidt collimator, two dichroic beamsplitters to separate the light into three channels, and for each channel a volume phase holographic (VPH) grating and a dual- corrector, modified Schmidt reimaging camera. This design provides a 275 mm collimated beam diameter, wide simultaneous wavelength coverage from 380 nm to 1.26 µm, and good imaging performance at the fast f/1.1 focal ratio required from the cameras to avoid oversampling the fibers. The three channels are designated as the blue, red, and near-infrared (NIR), and cover the bandpasses 380-650 nm (blue), 630-970 nm (red), and 0.94-1.26 µm (NIR). A mosaic of two Hamamatsu 2k×4k, 15 µm pixel CCDs records the spectra in the blue and red channels, while the NIR channel employs a 4k×4k, substrate-removed HAWAII-4RG array from Teledyne, with 15 µm pixels and a 1.7 µm wavelength cutoff. VPH gratings have become the dispersing element of choice for moderate-resolution astronomical spectro- graphs due their potential for very high diffraction efficiency, low scattered light, and the more compact instru- ment designs offered by transmissive dispersers. High quality VPH gratings are now routinely being produced in the sizes required for instruments on large telescopes. These factors made VPH gratings an obvious choice for PFS. In order to reduce risk to the project, as well as fully exploit the performance

  3. A SURVEY OF ASTRONOMICAL RESEARCH: A BASELINE FOR ASTRONOMICAL DEVELOPMENT

    International Nuclear Information System (INIS)

    Measuring scientific development is a difficult task. Different metrics have been put forward to evaluate scientific development; in this paper we explore a metric that uses the number of peer-reviewed, and when available non-peer-reviewed, research articles as an indicator of development in the field of astronomy. We analyzed the available publication record, using the Smithsonian Astrophysical Observatory/NASA Astrophysics Database System, by country affiliation in the time span between 1950 and 2011 for countries with a gross national income of less than 14,365 USD in 2010. This represents 149 countries. We propose that this metric identifies countries in ''astronomical development'' with a culture of research publishing. We also propose that for a country to develop in astronomy, it should invest in outside expert visits, send its staff abroad to study, and establish a culture of scientific publishing. Furthermore, we propose that this paper may be used as a baseline to measure the success of major international projects, such as the International Year of Astronomy 2009

  4. A Survey of Astronomical Research: A Baseline for Astronomical Development

    Science.gov (United States)

    Ribeiro, V. A. R. M.; Russo, P.; Cárdenas-Avendaño, A.

    2013-12-01

    Measuring scientific development is a difficult task. Different metrics have been put forward to evaluate scientific development; in this paper we explore a metric that uses the number of peer-reviewed, and when available non-peer-reviewed, research articles as an indicator of development in the field of astronomy. We analyzed the available publication record, using the Smithsonian Astrophysical Observatory/NASA Astrophysics Database System, by country affiliation in the time span between 1950 and 2011 for countries with a gross national income of less than 14,365 USD in 2010. This represents 149 countries. We propose that this metric identifies countries in "astronomical development" with a culture of research publishing. We also propose that for a country to develop in astronomy, it should invest in outside expert visits, send its staff abroad to study, and establish a culture of scientific publishing. Furthermore, we propose that this paper may be used as a baseline to measure the success of major international projects, such as the International Year of Astronomy 2009.

  5. Astronomical Polarimetry : new concepts, new instruments, new measurements & observations

    NARCIS (Netherlands)

    Snik, F.

    2009-01-01

    All astronomical sources are polarized to some degree. Polarimetry is therefore a powerful astronomical technique. It furnishes unique diagnostics of e.g. magnetic fields and scattering media. This thesis presents new polarimetric concepts, instruments, and measurements targeting astronomical scienc

  6. On-line correction of aberrations in particle spectrographs

    International Nuclear Information System (INIS)

    A new method is presented that allows the reconstruction of trajectories and the on-line correction of residual aberrations that limit the resolution of particle spectrographs. Using a computed or fitted high order transfer map that describes the uncorrected aberrations of the spectrograph under consideration, it is possible to determine a pseudo transfer map that allows the computation of the corrected data of interest as well as the reconstructed trajectories in terms of position measurements in two planes near the focal plane. The technique is only limited by the accuracy of the position measurements and the accuracy of the transfer map. In practice the method can be expressed as an inversion of a pseudo transfer map and implemented in the differential algebraic framework. The method will be used to correct residual high aberrations in the S800 spectrograph which is under construction at the National Superconducting Cyclotron Laboratory at Michigan State University

  7. Young Galaxy's Magnetism Surprises Astronomers

    Science.gov (United States)

    2008-10-01

    Astronomers have made the first direct measurement of the magnetic field in a young, distant galaxy, and the result is a big surprise. Looking at a faraway protogalaxy seen as it was 6.5 billion years ago, the scientists measured a magnetic field at least 10 times stronger than that of our own Milky Way. They had expected just the opposite. The GBT Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF The scientists made the discovery using the National Science Foundation's ultra-sensitive Robert C. Byrd Green Bank Telescope (GBT) in West Virginia. "This new measurement indicates that magnetic fields may play a more important role in the formation and evolution of galaxies than we have realized," said Arthur Wolfe, of the University of California-San Diego (UCSD). At its great distance, the protogalaxy is seen as it was when the Universe was about half its current age. According to the leading theory, cosmic magnetic fields are generated by the dynamos of rotating galaxies -- a process that would produce stronger fields with the passage of time. In this scenario, the magnetic fields should be weaker in the earlier Universe, not stronger. The new, direct magnetic-field measurement comes on the heels of a July report by Swiss and American astronomers who made indirect measurements that also implied strong magnetic fields in the early Universe. "Our results present a challenge to the dynamo model, but they do not rule it out," Wolfe said. There are other possible explanations for the strong magnetic field seen in the one protogalaxy Wolfe's team studied. "We may be seeing the field close to the central region of a massive galaxy, and we know such fields are stronger toward the centers of nearby galaxies. Also, the field we see may have been amplified by a shock wave caused by the collision of two galaxies," he said. The protogalaxy studied with the GBT, called DLA-3C286, consists of gas with little or no star formation occurring in it. The astronomers suspect that

  8. The AVES adaptive optics spectrograph for the VLT: status report

    Science.gov (United States)

    Pallavicini, Roberto; Delabre, Bernard; Pasquini, Luca; Zerbi, Filippo M.; Bonanno, Giovanni; Comari, Maurizio; Conconi, Paolo; Mazzoleni, Ruben; Santin, Paolo; Damiani, Francesco; Di Marcantonio, Paolo; Franchini, Mariagrazia; Spano, Paolo; Bonifacio, P.; Catalano, Santo; Molaro, Paolo P.; Randich, S.; Rodono, Marcello

    2003-03-01

    We report on the status of AVES, the Adaptive-optics Visual Echelle Spectrograph proposed for the secondary port of the Nasmyth Adaptive Optics System (NAOS) recently installed at the VLT. AVES is an intermediate resolution (R ≍ 16,000) high-efficiency fixed- format echelle spectrograph which operates in the spectral band 500 - 1,000 nm. In addition to a high intrinsic efficiency, comparable to that of ESI at Keck II, it takes advantage of the adaptive optics correction provided by NAOS to reduce the sky and detector contribution in background-limited observations of weak sources, thus allowing a further magnitude gain with respect to comparable non-adaptive optics spectrographs. Simulations show that the instrument will be capable of reaching a magnitude V = 22.5 at S/N > 10 in two hours, two magnitudes weaker than GIRAFFE at the same resolution and 3 magnitudes weaker than the higher resolution UVES spectrograph. Imaging and coronographic functions have also been implemented in the design. We present the results of the final design study and we dicuss the technical and operational issues related to its implementation at the VLT as a visitor instrument. We also discuss the possibility of using a scaled-up non-adaptive optics version of the same design as an element of a double- or triple-arm intermediate-resolution spectrograph for the VLT. Such an option looks attractive in the context of a high-efficiency large-bandwidth (320 - 1,500 nm) spectrograph ("fast-shooter") being considered by ESO as a 2nd-generation VLT instrument.

  9. Integrated optics for astronomical interferometry; 2, First laboratory white-light interferograms

    CERN Document Server

    Berger, J P; Kern, P; Malbet, M; Schanen-Duport, J P; Reynaud, P; Haguenauer, P; Benech, P

    1999-01-01

    We report first white-light interferograms obtained with an integrated optics beam combiner on a glass plate. These results demonstrate the feasability of single-mode interferometric beam combination with integrated optics technology presented and discussed in paper I. The demonstration is achieved in laboratory with off-the-shelves components coming from micro-sensor applications, not optimized for astronomical use. These two-telescope beam combiners made by ion exchange technique on glass substrate provide laboratory white-light interferograms simultaneously with photometric calibration. A dedicated interferometric workbench using optical fibers is set up to characterize these devices. Despite the rather low match of the component parameters to astronomical constraints, we obtain stable contrasts higher than 93% with a 1.54-\\micron laser source and up to 78% with a white-light source in the astronomical H band. Global throughput of 27% for a potassium ion exchange beam combiner and of 43% for a silver one a...

  10. An integral field spectrograph for SNAP supernova studies

    Energy Technology Data Exchange (ETDEWEB)

    Ealet, Anne; Prieto, E.; Bonissent, A.; Malina, R.; Basa, S.; LeFevre, O.; Mazure, A.; Tarle, G.; Akerlof, C.W.; Aldering, G.; Amidei, D.E.; Astier, P.; Baden, A.R.; Bebek, C.; Bergstrom, L.; Bernstein, G.M.; Bower, C.R.; Campbell, M.; Carithers Jr., W.C.; Commins, E.D.; Curtis, D.W.; Deustua, S.E.; Edwards, W.R.; Ellis, R.S.; Fruchter, A.; Frye, B.L.; Genat, J.; Goldhaber, G.; Goobar, A.; Goodman, J.A.; Graham, J.R.; Hardin, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Honeycutt, R.; Holland, S.E.; Hook, I.; Huterer, D.; Kasen, D.N.; Kim, A.G.; Knop, R.A.; Lafever, R.; Lampton, M.L.; Levi, M.E.; Levin, D.S.; Levy, J.M.; Lidman, C.; Lin, R.P.; Linder, E.V.; Loken, S.C.; McKay, T.; McKee, S.P.; Metzger, M.R.; Miquel, R.; Mourao, A.; Mufson, S.; Musser, J.A.; Nugent, P.E.; Pain, R.; Pankow, D.H.; Pennypacker, C.R.; Perlmutter, S.; Refregier, A.; Rich, J.; Robinson, K.E.; Schahmaneche, K.; Schubnell, M.S.; Spadafora, A.; Smoot, G.F.; Sullivan, G.W.; Tomasch, A.D.; SNAP Collaboration

    2002-07-29

    A well-adapted spectrograph concept has been developed for the SNAP (SuperNova/Acceleration Probe) experiment. The goal is to ensure proper identification of Type Ia supernovae and to standardize the magnitude of each candidate by determining explosion parameters. An instrument based on an integral field method with the powerful concept of imager slicing has been designed and is presented in this paper. The spectrograph concept is optimized to have very high efficiency and low spectral resolution (R {approx} 100), constant through the wavelength range (0.35-1.7{micro}m), adapted to the scientific goals of the mission.

  11. The Cosmic Origins Spectrograph: On-Orbit Instrument Performance

    CERN Document Server

    Osterman, S; Froning, C; Béland, S; Burgh, E; France, K; Penton, S; Delker, T; Ebbets, D; Sahnow, D; Bacinski, J; Kimble, R; Andrews, J; Wilkinson, E; McPhate, J; Siegmund, O; Ake, T; Aloisi, A; Biagetti, C; Diaz, R; Dixon, W; Friedman, S; Ghavamian, P; Goudfrooij, P; Hartig, G; Keyes, C; Lennon, D; Massa, D; Niemi, S; Oliveira, C; Osten, R; Proffitt, C; Smith, T; Soderblom, D

    2010-01-01

    The Cosmic Origins Spectrograph (COS) was installed in the Hubble Space Telescope in May, 2009 as part of Servicing Mission 4 to provide high sensitivity, medium and low resolution spectroscopy at far- and near-ultraviolet wavelengths (FUV, NUV). COS is the most sensitive FUV/NUV spectrograph flown to date, spanning the wavelength range from 900{\\AA} to 3200{\\AA} with peak effective area approaching 3000 cm^2. This paper describes instrument design, the results of the Servicing Mission Orbital Verification (SMOV), and the ongoing performance monitoring program.

  12. Astronomical pipeline processing using fuzzy logic

    Science.gov (United States)

    Shamir, Lior

    In the past few years, pipelines providing astronomical data have been becoming increasingly important. The wide use of robotic telescopes has provided significant discoveries, and sky survey projects such as SDSS and the future LSST are now considered among the premier projects in the field astronomy. The huge amount of data produced by these pipelines raises the need for automatic processing. Astronomical pipelines introduce several well-defined problems such as astronomical image compression, cosmic-ray hit rejection, transient detection, meteor triangulation and association of point sources with their corresponding known stellar objects. We developed and applied soft computing algorithms that provide new or improved solutions to these growing problems in the field of pipeline processing of astronomical data. One new approach that we use is fuzzy logic-based algorithms, which enables the automatic analysis of the astronomical pipelines and allows mining the data for not-yet-known astronomical discoveries such as optical transients and variable stars. The developed algorithms have been tested with excellent results on the NightSkyLive sky survey, which provides a pipeline of 150 astronomical pictures per hour, and covers almost the entire global night sky.

  13. On-sky calibration performance of a monolithic Michelson interferometer filtered source

    Science.gov (United States)

    Ge, Jian; Ma, Bo; Powell, Scott; Varosi, Frank; Schofield, Sidney; Grieves, Nolan; Liu, Jian

    2014-07-01

    In the new era of searching for Earth-like planets, new generation radial velocity (RV) high resolution spectrographs requires ~0.1 m/s Doppler calibration accuracy in the visible band and a similar calibration precision in the near infrared. The patented stable monolithic Michelson interferometer filtered source called the Sine source emerges as a very promising calibration device. This Sine source has the potential of covering the practical working wavelengths (~0.38- 2.5 μm) for Doppler measurements with high resolution optical and near infrared high resolution spectrographs at the ground-based telescopes. The single frame calibration precision can reach art spectrographs, and it can be easily designed to match the intrinsic sensitivities of future Doppler instruments. The Sine source also has the great practical advantages in compact (portable) size and low cost. Here we report early results from on-sky calibration of a Sine source measured with two state-of-the-art TOU optical high resolution spectrograph (R=100,000, 0.38-0.9 microns) and FIRST near infrared spectrograph (R=50,000, 0.8-1.8 microns) at a 2 meter robotic telescope at Fairborn Observatory in Arizona. The results with the TOU spectrograph monitoring over seven days show that the Sine source has produced ~3 times better calibration precision than the ThAr calibration (RMS = 2.7m/s vs. 7.4m/s) at 0.49-0.62 microns where calibration data have been processed by our preliminary data pipeline and ~1.4 times better than the iodine absorption spectra (RMS=3.6 m/s) at the same wavelength region. As both ThAr and Iodine have reached sub m/s calibration accuracy with existing Doppler instruments (such as HARPS and HIRES), it is likely that the sine source would provide similar improvement once a better data pipeline and an upgraded version of a Sine source are developed. It is totally possible to reach ~0.1 m/s in the optical wavelength region. In addition, this Sine source offers potential very accurate

  14. Astronomical Surveys and Big Data

    CERN Document Server

    Mickaelian, A M

    2015-01-01

    Recent all-sky and large-area astronomical surveys and their catalogued data over the whole range of electromagnetic spectrum are reviewed, from Gamma-ray to radio, such as Fermi-GLAST and INTEGRAL in Gamma-ray, ROSAT, XMM and Chandra in X-ray, GALEX in UV, SDSS and several POSS I and II based catalogues (APM, MAPS, USNO, GSC) in optical range, 2MASS in NIR, WISE and AKARI IRC in MIR, IRAS and AKARI FIS in FIR, NVSS and FIRST in radio and many others, as well as most important surveys giving optical images (DSS I and II, SDSS, etc.), proper motions (Tycho, USNO, Gaia), variability (GCVS, NSVS, ASAS, Catalina, Pan-STARRS) and spectroscopic data (FBS, SBS, Case, HQS, HES, SDSS, CALIFA, GAMA). An overall understanding of the coverage along the whole wavelength range and comparisons between various surveys are given: galaxy redshift surveys, QSO/AGN, radio, Galactic structure, and Dark Energy surveys. Astronomy has entered the Big Data era. Astrophysical Virtual Observatories and Computational Astrophysics play a...

  15. Astronomical surveys and big data

    Science.gov (United States)

    Mickaelian, Areg M.

    Recent all-sky and large-area astronomical surveys and their catalogued data over the whole range of electromagnetic spectrum, from γ -rays to radio waves, are reviewed, including such as Fermi-GLAST and INTEGRAL in γ -ray, ROSAT, XMM and Chandra in X-ray, GALEX in UV, SDSS and several POSS I and POSS II-based catalogues (APM, MAPS, USNO, GSC) in the optical range, 2MASS in NIR, WISE and AKARI IRC in MIR, IRAS and AKARI FIS in FIR, NVSS and FIRST in radio range, and many others, as well as the most important surveys giving optical images (DSS I and II, SDSS, etc.), proper motions (Tycho, USNO, Gaia), variability (GCVS, NSVS, ASAS, Catalina, Pan-STARRS), and spectroscopic data (FBS, SBS, Case, HQS, HES, SDSS, CALIFA, GAMA). An overall understanding of the coverage along the whole wavelength range and comparisons between various surveys are given: galaxy redshift surveys, QSO/AGN, radio, Galactic structure, and Dark Energy surveys. Astronomy has entered the Big Data era, with Astrophysical Virtual Observatories and Computational Astrophysics playing an important role in using and analyzing big data for new discoveries.

  16. Astronomical Knowledge in Holy Books

    Science.gov (United States)

    Farmanyan, Sona V.; Mickaelian, Areg M.

    2015-08-01

    We investigate religious myths related to astronomy from different cultures in an attempt to identify common subjects and characteristics. The paper focuses on astronomy in religion. The initial review covers records from Holy books about sky related superstitious beliefs and cosmological understanding. The purpose of this study is to introduce sky related religious and national traditions (particularly based on different calendars; Solar or Lunar). We carried out a comparative study of astronomical issues contained in a number of Holy books: Ancient Egyptian Religion (Pyramid Texts), Zoroastrianism (Avesta), Hinduism (Vedas), Buddhism (Tipitaka), Confucianism (Five Classics), Sikhism (Guru Granth Sahib), Christianity (Bible), Islam (Quran), Druidism (Mabinogion) and Maya Religion (Popol Vuh). These books include various information on the creation of the Universe, Sun and Moon, the age of the Universe, Cosmic sizes, understanding about the planets, stars, Milky Way and description of the Heavens in different religions. We come to the conclusion that the perception of celestial objects varies from culture to culture, and from religion to religion and preastronomical views had a significant impact on humankind, particularly on religious diversities. We prove that Astronomy is the basis of cultures, and that national identity and mythology and religion were formed due to the special understanding of celestial objects.

  17. VEGAS: VErsatile GBT Astronomical Spectrometer

    Science.gov (United States)

    Bussa, Srikanth; VEGAS Development Team

    2012-01-01

    The National Science Foundation Advanced Technologies and Instrumentation (NSF-ATI) program is funding a new spectrometer backend for the Green Bank Telescope (GBT). This spectrometer is being built by the CICADA collaboration - collaboration between the National Radio Astronomy Observatory (NRAO) and the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California Berkeley.The backend is named as VErsatile GBT Astronomical Spectrometer (VEGAS) and will replace the capabilities of the existing spectrometers. This backend supports data processing from focal plane array systems. The spectrometer will be capable of processing up to 1.25 GHz bandwidth from 8 dual polarized beams or a bandwidth up to 10 GHz from a dual polarized beam.The spectrometer will be using 8-bit analog to digital converters (ADC), which gives a better dynamic range than existing GBT spectrometers. There will be 8 tunable digital sub-bands within the 1.25 GHz bandwidth, which will enhance the capability of simultaneous observation of multiple spectral transitions. The maximum spectral dump rate to disk will be about 0.5 msec. The vastly enhanced backend capabilities will support several science projects with the GBT. The projects include mapping temperature and density structure of molecular clouds; searches for organic molecules in the interstellar medium; determination of the fundamental constants of our evolving Universe; red-shifted spectral features from galaxies across cosmic time and survey for pulsars in the extreme gravitational environment of the Galactic Center.

  18. Franklin Edward Kameny (1925-2011, Astronomer)

    Science.gov (United States)

    Wright, Jason

    2012-01-01

    Dr. Frank Kameny is best known today as one of the most important members of the gay rights movement in the United States, but he was also a PhD astronomer. In fact, it was his firing from his civil service position as astronomer for the US Army Map Service on the grounds of homosexuality that sparked his lifelong career of activism. Here, I explore some aspects of his short but interesting astronomical career and the role of the AAS in his life.

  19. Astronomical problems an introductory course in astronomy

    CERN Document Server

    Vorontsov-Vel'Yaminov, B A

    1969-01-01

    Astronomical Problems: An Introductory Course in Astronomy covers astronomical problems, together with a summary of the theory and the formula to be exercised. The book discusses the types of problems solved with the help of the celestial globe and how to solve astronomical problems. The text tackles problems on interpolation, the celestial sphere, systems of celestial coordinates, and culmination. Problems about the rising and setting of a heavenly body, precession, planetary movement, and parallax and aberration are also considered. The book presents problems about refraction, the apparent m

  20. Commissioning MOS and Fabry-Perot modes for the Robert Stobie Spectrograph on the Southern African Large Telescope

    Science.gov (United States)

    Koeslag, A. R.; Williams, T. B.; Nordsieck, K. H.; Romero-Colmenero, E.; Vaisanen, P. H.; Maartens, D. S.

    2014-07-01

    The Southern African Large Telescope (SALT) currently has three instruments: the imaging SALTICAM, the new High Resolution Spectrograph (HRS) which is in the process of being commissioned and the Robert Stobie Spectrograph (RSS). RSS has multiple science modes, of which long slit spectroscopy was originally commissioned; We have commissioned two new science modes: Multi Object Spectroscopy (MOS) and Fabry-Perot (FP). Due to the short track times available on SALT it is vital that acquisition is as efficient as possible. This paper will discuss how we implemented these modes in software and some of the challenges we had to overcome. MOS requires a slit-mask to be aligned with a number of stars. This is done in two phases: in MOS calibration the positions of the slits are detected using a through-slit image and RA/DEC database information, and in MOS acquisition the detector sends commands to the telescope control system (TCS) in an iterative and interactive fashion for fine mask/detector alignment to get the desired targets on the slits. There were several challenges involved with this system, and the user interface evolved to make the process as efficient as possible. We also had to overcome problems with the manufacturing process of the slit-masks. FP requires the precise alignment each of the two etalons installed on RSS. The software makes use of calibration tables to get the etalons into roughly aligned starting positions. An exposure is then done using a calibration arc lamp, producing a ring pattern. Measurement of the rings allows the determination of the adjustments needed to properly align the etalons. The software has been developed to optimize this process, along with software tools that allow us to fine tune the calibration tables. The software architecture allows the complexity of automating the FP calibration and procedures to be easily managed.

  1. A Warm Near-Infrared High-Resolution Spectrograph with Very High Throughput (WINERED)

    CERN Document Server

    Kondo, Sohei; Kobayashi, Naoto; Yasui, Chikako; Mito, Hiroyuki; Fukue, Kei; Nakanishi, Kenshi; Kawanishi, Takafumi; Nakaoka, Tetsuya; Otsubo, Shogo; Kinoshita, Masaomi; Kitano, Ayaka; Hamano, Satoshi; Mizumoto, Misaki; Yamamoto, Ryo; Izumi, Natsuko; Matsunaga, Noriyuki; Kawakita, Hideyo

    2015-01-01

    WINERED is a newly built high-efficiency (throughput$ > 25-30\\%$) and high-resolution spectrograph customized for short NIR bands at 0.9-1.35 ${\\rm \\mu}$m. WINERED is equipped with ambient temperature optics and a cryogenic camera using a 1.7 ${\\rm \\mu}$m cut-off HgCdTe HAWAII-2RG array detector. WINERED has two grating modes: one with a conventional reflective echelle grating (R$\\sim$28,300), which covers 0.9-1.35 $\\mu$m simultaneously, the other with ZnSe or ZnS immersion grating (R$\\sim$100,000). We have completed the development of WINERED except for the immersion grating, and started engineering and science observations at the Nasmyth platform of the 1.3 m Araki Telescope at Koyama Astronomical Observatory of Kyoto-Sangyo University in Japan. We confirmed that the spectral resolution ($R\\sim$ 28,300) and the throughput ($>$ 40\\% w/o telescope/atmosphere/array QE) meet our specifications. We measured ambient thermal backgrounds (e.g., 0.06 ${\\rm [e^{-}/sec/pixel]}$ at 287 K), which are roughly consistent ...

  2. AVES: an adaptive optics visual echelle spectrograph for the VLT

    Science.gov (United States)

    Pasquini, Luca; Delabre, Bernard; Avila, Gerardo; Bonaccini, Domenico

    1998-07-01

    We present the preliminary study of a low cost, high performance spectrograph for the VLT, for observations in the V, R and I bands. This spectrograph is meant for intermediate (R equals 16,000) resolution spectroscopy of faint (sky and/or detector limited) sources, with particular emphasis on the study of solar-type (F-G) stars belonging to the nearest galaxies and to distant (or highly reddened) galactic clusters. The spectrograph is designed to use the adaptive optics (AO) systems at the VLT Telescope. Even if these AO systems will not provide diffraction limited images in the V, R and I bands, the photon concentration will still be above approximately 60% of the flux in an 0.3 arcsecond aperture for typical Paranal conditions. This makes the construction of a compact, cheap and efficient echelle spectrograph possible. AVES will outperform comparable non adaptive optic instruments by more than one magnitude for sky- and/or detector-limited observations, and it will be very suitable for observations in crowded fields.

  3. Galactic Archaeology with the Subaru Prime Focus Spectrograph

    Science.gov (United States)

    Chiba, Masashi; Cohen, Judith; Wyse, Rosemary F. G.

    2016-08-01

    We present an overview of our Galactic Archaeology (GA) survey program with the Prime Focus Spectrograph (PFS) for Subaru. Following successful design reviews, the instrument is now under construction with first light anticipated in 2018. Main characteristics of PFS and the science goals in our PFS/GA program are described.

  4. First Light Results from the Hermes Spectrograph at the AAT

    CERN Document Server

    Sheinis, Andrew; Asplund, Martin; Bacigalupo, Carlos; Barden, Sam; Birchall, Michael; Bland-Hawthorn, Joss; Brzeski, Jurek; Cannon, Russell; Carollo, Daniela; Case, Scott; Casey, Andrew; Churilov, Vladimir; Warrick, Couch; Dean, Robert; De Silva, Gayandhi; D'Orazi, Valentina; Duong, Ly; Farrell, Tony; Fiegert, Kristin; Freeman, Kenneth; Gabriella, Frost; Gers, Luke; Goodwin, Michael; Gray, Doug; Green, Andrew; Heald, Ron; Heijmans, Jeroen; Ireland, Michael; Jones, Damien; Kafle, Prajwal; Keller, Stefan; Klauser, Urs; Kondrat, Yuriy; Kos, Janez; Lawrence, Jon; Lee, Steve; Mali, Slavko; Martell, Sarah; Mathews, Darren; Mayfield, Don; Miziarski, Stan; Muller, Rolf; Pai, Naveen; Patterson, Robert; Penny, Ed; Orr, David; Schlesinger, Katharine; Sharma, Sanjib; Shortridge, Keith; Simpson, Jeffrey; Smedley, Scott; Smith, Greg; Stafford, Darren; Staszak, Nicholas; Vuong, Minh; Waller, Lewis; de Boer, Elizabeth Wylie; Xavier, Pascal; Zheng, Jessica; Zhelem, Ross; Zucker, Daniel; Zwitter, Tomaz

    2015-01-01

    The High Efficiency and Resolution Multi Element Spectrograph, HERMES, is a facility-class optical spectrograph for the Anglo-Australian Telescope (AAT). It is designed primarily for Galactic Archaeology, the first major attempt to create a detailed understanding of galaxy formation and evolution by studying the history of our own galaxy, the Milky Way. The goal of the GALAH survey is to reconstruct the mass assembly history of the Milky Way through a detailed chemical abundance study of one million stars. The spectrograph is based at the AAT and is fed by the existing 2dF robotic fiber positioning system. The spectrograph uses volume phase holographic gratings to achieve a spectral resolving power of 28,000 in standard mode and also provides a high-resolution mode ranging between 40,000 and 50,000 using a slit mask. The GALAH survey requires an SNR greater than 100 for a star brightness of V ?= 14 in an exposure time of one hour. The total spectral coverage of the four channels is about 100 nm between 370 an...

  5. Hectospec, the MMT's 300 Optical Fiber-Fed Spectrograph

    CERN Document Server

    Fabricant, D; Roll, J; Hertz, E; Caldwell, N; Gauron, T; Geary, J; McLeod, B; Szentgyorgyi, A H; Fabricant, Daniel; Fata, Robert; Roll, John; Hertz, Edward; Caldwell, Nelson; Gauron, Thomas; Geary, John; Leod, Brian Mc; Szentgyorgyi, Andrew

    2005-01-01

    The Hectospec is a 300 optical fiber fed spectrograph commissioned at the MMT in the spring of 2004. A pair of high-speed six-axis robots move the 300 fiber buttons between observing configurations within ~300 s and to an accuracy ~25 microns. The optical fibers run for 26 m between the MMT's focal surface and the bench spectrograph operating at R~1000-2000. Another high dispersion bench spectrograph offering R~5,000, Hectochelle, is also available. The system throughput, including all losses in the telescope optics, fibers, and spectrograph peaks at ~10% at the grating blaze in 1" FWHM seeing. Correcting for aperture losses at the 1.5" diameter fiber entrance aperture, the system throughput peaks at $\\sim$17%. Hectospec has proven to be a workhorse instrument at the MMT. Hectospec and Hectochelle together were scheduled for 1/3 of the available nights since its commissioning. Hectospec has returned \\~60,000 reduced spectra for 16 scientific programs during its first year of operation.

  6. CCD Readout Electronics for the Subaru Prime Focus Spectrograph

    CERN Document Server

    Hope, Stephen C; Loomis, Craig P; Fitzgerald, Roger E; Peacock, Grant O

    2014-01-01

    We present details of the design for the CCD readout electronics for the Subaru Telescope Prime Focus Spectrograph (PFS). The spectrograph is comprised of four identical spectrograph modules, each collecting roughly 600 spectra. The spectrograph modules provide simultaneous wavelength coverage over the entire band from 380 nm to 1260 nm through the use of three separate optical channels: blue, red, and near infrared (NIR). A camera in each channel images the multi-object spectra onto a 4k x 4k, 15 um pixel, detector format. The two visible cameras use a pair of Hamamatsu 2k x 4k CCDs with readout provided by custom electronics, while the NIR camera uses a single Teledyne HgCdTe 4k x 4k detector and ASIC Sidecar to read the device. The CCD readout system is a custom design comprised of three electrical subsystems: the Back End Electronics (BEE), the Front End Electronics (FEE), and a Pre-amplifier. The BEE is an off-the-shelf PC104 computer, with an auxiliary Xilinx FPGA module. The computer serves as the main...

  7. Astronomers find distant planet like Jupiter

    CERN Multimedia

    2003-01-01

    Astronomers searching for planetary systems like our solar system have found a planet similar to Jupiter orbiting a nearby star similar to our Sun, about 90 light-years from Earth, according to researchers (1/2 page).

  8. Longwave Imaging for Astronomical Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a compact portable longwave camera for astronomical applications. In Phase 1, we will develop and deliver the focal plane array (FPA) - a...

  9. Astronomers no longer in the dark

    CERN Multimedia

    MacMillan, L

    2002-01-01

    In a significant breakthrough, British and US astronomers have begun to pin down the most elusive material in the universe. They have made a map of dark matter - the heavy, invisible stuff that gives the galaxies their shape (1 page).

  10. Longwave Imaging for Astronomical Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a compact portable longwave camera for astronomical applications. In Phase 1, we successfully developed the eye of the camera, i.e. the focal...

  11. Astronomical data bases and retrieval systems

    Science.gov (United States)

    Mead, J. M.; Nagy, T. A.; Warren, W. H., Jr.

    1981-01-01

    The status of the development of machine-readable stellar and extragalactic data bases is summarized, including several examples of astronomical applications using these data sets. The creation of a computerized bibliographical data base for cometary research is described.

  12. Astronomers Unveiling Life's Cosmic Origins

    Science.gov (United States)

    2009-02-01

    Processes that laid the foundation for life on Earth -- star and planet formation and the production of complex organic molecules in interstellar space -- are yielding their secrets to astronomers armed with powerful new research tools, and even better tools soon will be available. Astronomers described three important developments at a symposium on the "Cosmic Cradle of Life" at the annual meeting of the American Association for the Advancement of Science in Chicago, IL. Chemistry Cycle The Cosmic Chemistry Cycle CREDIT: Bill Saxton, NRAO/AUI/NSF Full Size Image Files Chemical Cycle Graphic (above image, JPEG, 129K) Graphic With Text Blocks (JPEG, 165K) High-Res TIFF (44.2M) High-Res TIFF With Text Blocks (44.2M) In one development, a team of astrochemists released a major new resource for seeking complex interstellar molecules that are the precursors to life. The chemical data released by Anthony Remijan of the National Radio Astronomy Observatory (NRAO) and his university colleagues is part of the Prebiotic Interstellar Molecule Survey, or PRIMOS, a project studying a star-forming region near the center of our Milky Way Galaxy. PRIMOS is an effort of the National Science Foundation's Center for Chemistry of the Universe, started at the University of Virginia (UVa) in October 2008, and led by UVa Professor Brooks H. Pate. The data, produced by the NSF's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, came from more than 45 individual observations totalling more than nine GigaBytes of data and over 1.4 million individual frequency channels. Scientists can search the GBT data for specific radio frequencies, called spectral lines -- telltale "fingerprints" -- naturally emitted by molecules in interstellar space. "We've identified more than 720 spectral lines in this collection, and about 240 of those are from unknown molecules," Remijan said. He added, "We're making available to all scientists the best collection of data below 50 GHz ever produced for

  13. Publication and citation statistics for UK astronomers

    CERN Document Server

    Blustin, A J

    2007-01-01

    This article presents a survey of publication and citation statistics for 835 UK professional astronomers: the majority of academics and contract researchers within the UK astronomical community. I provide histograms of these bibliometrics for the whole sample as well as of the median values for the individual departments. I discuss the distribution of top bibliometric performers in the sample, and make some remarks on the usage of bibliometrics in a real-world assessment exercise.

  14. Astronomical Plate Archives and Binary Blazars Studies

    Indian Academy of Sciences (India)

    Rene Hudec

    2011-03-01

    There are about 3 million astronomical photographic plates around the globe, representing an important data source for various aspects of astrophysics. The main advantage is the large time coverage of 100 years or even more. Recent digitization efforts, together with the development of dedicated software, enables for the first time, effective data mining and data analyses by powerful computers with these archives. Examples of blazars proposed and/or investigated on the astronomical plates are presented and discussed.

  15. Bayesian mixture models for Poisson astronomical images

    OpenAIRE

    Guglielmetti, Fabrizia; Fischer, Rainer; Dose, Volker

    2012-01-01

    Astronomical images in the Poisson regime are typically characterized by a spatially varying cosmic background, large variety of source morphologies and intensities, data incompleteness, steep gradients in the data, and few photon counts per pixel. The Background-Source separation technique is developed with the aim to detect faint and extended sources in astronomical images characterized by Poisson statistics. The technique employs Bayesian mixture models to reliably detect the background as...

  16. Scalable Machine Learning for Massive Astronomical Datasets

    Science.gov (United States)

    Ball, Nicholas M.; Gray, A.

    2014-04-01

    We present the ability to perform data mining and machine learning operations on a catalog of half a billion astronomical objects. This is the result of the combination of robust, highly accurate machine learning algorithms with linear scalability that renders the applications of these algorithms to massive astronomical data tractable. We demonstrate the core algorithms kernel density estimation, K-means clustering, linear regression, nearest neighbors, random forest and gradient-boosted decision tree, singular value decomposition, support vector machine, and two-point correlation function. Each of these is relevant for astronomical applications such as finding novel astrophysical objects, characterizing artifacts in data, object classification (including for rare objects), object distances, finding the important features describing objects, density estimation of distributions, probabilistic quantities, and exploring the unknown structure of new data. The software, Skytree Server, runs on any UNIX-based machine, a virtual machine, or cloud-based and distributed systems including Hadoop. We have integrated it on the cloud computing system of the Canadian Astronomical Data Centre, the Canadian Advanced Network for Astronomical Research (CANFAR), creating the world's first cloud computing data mining system for astronomy. We demonstrate results showing the scaling of each of our major algorithms on large astronomical datasets, including the full 470,992,970 objects of the 2 Micron All-Sky Survey (2MASS) Point Source Catalog. We demonstrate the ability to find outliers in the full 2MASS dataset utilizing multiple methods, e.g., nearest neighbors. This is likely of particular interest to the radio astronomy community given, for example, that survey projects contain groups dedicated to this topic. 2MASS is used as a proof-of-concept dataset due to its convenience and availability. These results are of interest to any astronomical project with large and/or complex

  17. MOEMS devices designed and tested for astronomical instrumentation in space

    Science.gov (United States)

    Zamkotsian, Frederic; Noell, Wilfried

    2012-03-01

    Next-generation astronomical instrumentation for ground-based and space telescopes could use MOEMS devices. Among them, Multi-Object Spectrographs (MOS) are the major instruments for studying primary galaxies and remote and faint objects. A promising solution for the object selection system is the use of MOEMS devices such as micromirror arrays (MMA) which allow the remote control of the multi-slit configuration in real time. We are engaged in a European development of MMA for generating reflective slit masks. Prototypes of MMA with 2048 individually addressable micromirrors made of single-crystal silicon were successfully designed, fabricated and tested. 100×200μm2 micromirrors can be tilted by electrostatic actuation yielding 24° mechanical tilt-angle. The micromirrors were successfully actuated before, during and after cryogenic cooling at 162K. Line-column addressing for individual mirrors has also been demonstrated. We were also engaged in a technical assessment of using a 2048 × 1080 DMD from Texas Instruments for space applications. For a MOS in space, the device should work in vacuum and at low temperature. Our tests reveal that the DMD remains fully operational at -40°C and in vacuum. A 1038 hours life test in space survey conditions, Total Ionizing Dose radiation, thermal cycling and vibrations/shocks have also been successfully completed. These results do not reveal any show-stopper concerning the ability of the DMD to meet environmental space requirements. These developments and tests demonstrate the full ability of this type of components for space instrumentation, especially in multi-object spectroscopy applications.

  18. Large astronomical catalog management for telescope operations

    Science.gov (United States)

    Baruffolo, Andrea; Benacchio, Leopoldo

    1998-07-01

    Large astronomical catalogues containing from a million up to hundreds of millions records are currently available, even larger catalogues will be released in the near future. They will have an important operational role since they will be used throughout the observing cycle of next generation large telescopes, for proposal and observation preparation, telescope scheduling, selection of guide stars, etc. These large databases pose new problems for fast and general access. Solutions based on custom software or on customized versions of specific catalogues have been proposed, but the problem will benefit from a more general database approach. While traditional database technologies have proven to be inadequate for this task, new technologies are emerging, in particular that of Object Relational DBMSs, that seem to be suitable to solve the problem. In this paper we describe our experiences in experimenting with ORDBMSs for the management of large astronomical catalogues. We worked especially on the database query language and access methods. In the first field to extend the database query language capabilities with astronomical functionalities and to support typical astronomical queries.In the second, to speed up the execution of queries containing astronomical predicates.

  19. How Astronomers View Education and Public Outreach

    CERN Document Server

    Dang, Lisa

    2015-01-01

    Over the past few years, there have been a few studies on the development of an interest in science and scientists' views on public outreach. Yet, to date, there has been no global study regarding astronomers' views on these matters. Through the completion of our survey by 155 professional astronomers online and in person during the 28th International Astronomical Union General Assembly in 2012, we explored their development of and an interest for astronomy and their views on time constraints and budget restriction regarding public outreach activities. We find that astronomers develop an interest in astronomy between the ages of 4-6 but that the decision to undertake a career in astronomy often comes during late adolescence. We also discuss the claim that education and public outreach is regarded an optional task rather than a scientist's duty. Our study revealed that many astronomers think there should be a larger percentage of their research that should be invested into outreach activities, calling for a ch...

  20. Astrophotonic micro-spectrographs in the era of ELTs

    CERN Document Server

    Blind, N; Kern, P; Bland-Hawthorn, J

    2014-01-01

    The next generation of Extremely Large Telescopes (ELT), with diameters up to 39 meters, will start opera- tion in the next decade and promises new challenges in the development of instruments. The growing field of astrophotonics (the use of photonic technologies in astronomy) can partly solve this problem by allowing mass production of fully integrated and robust instruments combining various optical functions, with the potential to reduce the size, complexity and cost of instruments. In this paper, we focus on developments in integrated micro-spectrographs and their potential for ELTs. We take an inventory of the identified technologies currently in development, and compare the performance of the different concepts. We show that in the current context of single-mode instruments, integrated spectrographs making use of, e.g., a photonic lantern can be a solution to reach the desired performance. However, in the longer term, there is a clear need to develop multimode devices to improve overall the throughput a...

  1. GNOMOS: The Gemini NIR-Optical Multi Object Spectrograph

    CERN Document Server

    Schiavon, Ricardo P; Chiboucas, Kristin; Diaz, Ruben; Geballe, Tom; Gimeno, German; Gomez, Percy; Hibon, Pascale; Hirst, Paul; Jorgensen, Inger; Labrie, Kathleen; Leggett, Sandy; Lemoine-Busserolle, Marie; Levenson, Nancy; Mason, Rachel; McDermid, Richard; Miller, Bryan; Nitta, Atsuko; Pessev, Peter; Rodgers, Bernadette; Schirmer, Mischa; Trujillo, Chad; Turner, James

    2012-01-01

    This paper is a response to a call for white papers solicited by Gemini Observatory and its Science and Technology Advisory Committee, to help define the science case and requirements for a new Gemini instrument, envisaged to consist of a single-object spectrograph at medium resolution simultaneously covering optical and near-infrared wavelengths. In this white paper we discuss the science case for an alternative new instrument, consisting instead of a multi-object, medium-resolution, high-throughput spectrograph, covering simultaneously the optical and near-infrared slices of the electromagnetic spectrum. We argue that combination of wide wavelength coverage at medium resolution with moderate multiplexing power is an innovative path that will enable the pursuit of fundamental science questions in a variety of astrophysical topics, without compromise of the science goals achievable by single-object spectroscopy on a wide baseline. We present a brief qualitative discussion of the main features of a notional ha...

  2. WUVS spectrographs of World Space Observatory - Ultraviolet project

    Science.gov (United States)

    Savanov, Igor; Sachkov, Mikhail; Shustov, Boris M.; Shugarov, Andrey

    2016-07-01

    WSO-UV (World Space Observatory - Ultraviolet) project is an international space observatory designed for observations in the UV (115 - 320 nm). It includes a 170 cm aperture telescope capable of high-resolution spectroscopy, long slit low-resolution spectroscopy and deep UV and optical imaging. WUVS - the set of three ultraviolet spectrographs are regarded as the main instrument of «Spektr -UF» space mission. The spectrographs unit includes three channels and is intended for acquisition of spectrums of high (R=50000) and low (R=1000) resolution of the observed objects in the electromagnetic radiation's ultraviolet range (115-310 nm). We present the design philosophy of WUVS and summarize its key characteristics. We shall present the main properties of WUVS new structure and current status of its mockups and prototypes manufacturing.

  3. The Integral Field Spectrograph for the Gemini Planet Imager

    CERN Document Server

    Larkin, James E; Aliado, Theodore; Bauman, Brian J; Brims, George; Canfield, John M; Cardwell, Andrew; Dillon, Daren; Doyon, René; Dunn, Jennifer; Fitzgerald, Michael P; Graham, James R; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Ingraham, Patrick; Johnson, Christopher A; Kress, Evan; Konopacky, Quinn M; Macintosh, Bruce A; Magnone, Kenneth G; Maire, Jérôme; McLean, Ian S; Palmer, David; Perrin, Marshall D; Quiroz, Carlos; Rantakyrö, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Serio, Andrew; Thibault, Simon; Thomas, Sandrine J; Vallee, Philippe; Weiss, Jason L

    2014-01-01

    The Gemini Planet Imager (GPI) is a complex optical system designed to directly detect the self-emission of young planets within two arcseconds of their host stars. After suppressing the starlight with an advanced AO system and apodized coronagraph, the dominant residual contamination in the focal plane are speckles from the atmosphere and optical surfaces. Since speckles are diffractive in nature their positions in the field are strongly wavelength dependent, while an actual companion planet will remain at fixed separation. By comparing multiple images at different wavelengths taken simultaneously, we can freeze the speckle pattern and extract the planet light adding an order of magnitude of contrast. To achieve a bandpass of 20%, sufficient to perform speckle suppression, and to observe the entire two arcsecond field of view at diffraction limited sampling, we designed and built an integral field spectrograph with extremely low wavefront error and almost no chromatic aberration. The spectrograph is fully cr...

  4. Ultraviolet spectrographs for thermospheric and ionospheric remote sensing

    International Nuclear Information System (INIS)

    The Naval Research Laboratory (NRL) has been developing far- and extreme-ultraviolet spectrographs for remote sensing the Earth's upper atmosphere and ionosphere. The first of these sensors, called the Special Sensor Ultraviolet Limb Imager (SSULI), will be flying on the Air Force's Defense Meteorological Satellite Program (DMSP) block 5D3 satellites as an operational sensor in the 1997-2010 time frame. A second sensor, called the High-resolution ionospheric and Thermospheric Spectrograph (HITS), will fly in late 1995 on the Air Force Space Test Program's Advanced Research and Global Observation Satellite (ARGOS, also known as P91-1) as part of NRL's High Resolution Airglow and Auroral Spectroscopy (HIRAAS) experiment. Both of these instruments are compact and do not draw much power and would be good candidates for small satellite applications. The instruments and their capabilities are discussed. Possible uses of these instruments in small satellite applications are also presented

  5. Very fast transmissive spectrograph designs for highly multiplexed fiber spectroscopy

    CERN Document Server

    Saunders, Will

    2016-01-01

    Very fast (f/1.2 and f/1.35) transmissive spectrograph designs are presented for Hector and MSE. The designs have 61mm x 61mm detectors, 4 or 5 camera lenses of aperture less than 228mm, with just 6 air/glass surfaces, and rely on extreme aspheres for their imaging performance. The throughput is excellent, because of the i-line glasses used, the small number of air/glass surfaces.

  6. Exposure Time Calculator for Immersion Grating Infrared Spectrograph: IGRINS

    OpenAIRE

    Le, Huynh Anh N.; Pak, Soojong; Jaffe, Daniel T.; Kaplan, Kyle; Lee, Jae-Joon; Im, Myungshin; Seifahrt, Andreas

    2015-01-01

    We present an exposure-time calculator (ETC) for the Immersion Grating Infrared Spectrograph (IGRINS). The signal and noise values are calculated by taking into account the telluric background emission and absorption, the emission and transmission of the telescope and instrument optics, and the dark current and read noise of the infrared detector arrays. For the atmospheric transmission, we apply models based on the amount of precipitable water vapor along the line of sight to the target. The...

  7. First light results from the Hermes spectrograph at the AAT

    Science.gov (United States)

    Sheinis, Andrew; Barden, Sam; Birchall, Michael; Carollo, Daniela; Bland-Hawthorn, Joss; Brzeski, Jurek; Case, Scott; Cannon, Russell; Churilov, Vladimir; Couch, Warrick; Dean, Robert; De Silva, Gayandhi; D'Orazi, Valentina; Farrell, Tony; Fiegert, Kristin; Freeman, Kenneth; Frost, Gabriella; Gers, Luke; Goodwin, Michael; Gray, Doug; Heald, Ron; Heijmans, Jeroen; Jones, Damien; Keller, Stephan; Klauser, Urs; Kondrat, Yuriy; Lawrence, Jon; Lee, Steve; Mali, Slavko; Martell, Sarah; Mathews, Darren; Mayfield, Don; Miziarski, Stan; Muller, Rolf; Pai, Naveen; Patterson, Robert; Penny, Ed; Orr, David; Shortridge, Keith; Simpson, Jeffrey; Smedley, Scott; Smith, Greg; Stafford, Darren; Staszak, Nicholas; Vuong, Minh; Waller, Lewis; Wylie de Boer, Elizabeth; Xavier, Pascal; Zheng, Jessica; Zhelem, Ross; Zucker, Daniel

    2014-07-01

    The High Efficiency and Resolution Multi Element Spectrograph, HERMES is an facility-class optical spectrograph for the AAT. It is designed primarily for Galactic Archeology [21], the first major attempt to create a detailed understanding of galaxy formation and evolution by studying the history of our own galaxy, the Milky Way. The goal of the GALAH survey is to reconstruct the mass assembly history of the of the Milky Way, through a detailed spatially tagged abundance study of one million stars. The spectrograph is based at the Anglo Australian Telescope (AAT) and is fed by the existing 2dF robotic fiber positioning system. The spectrograph uses VPH-gratings to achieve a spectral resolving power of 28,000 in standard mode and also provides a high-resolution mode ranging between 40,000 to 50,000 using a slit mask. The GALAH survey requires a SNR greater than 100 for a star brightness of V=14. The total spectral coverage of the four channels is about 100nm between 370 and 1000nm for up to 392 simultaneous targets within the 2 degree field of view. Hermes has been commissioned over 3 runs, during bright time in October, November and December 2013, in parallel with the beginning of the GALAH Pilot survey starting in November 2013. In this paper we present the first-light results from the commissioning run and the beginning of the GALAH Survey, including performance results such as throughput and resolution, as well as instrument reliability. We compare the abundance calculations from the pilot survey to those in the literature.

  8. An Interface Region Imaging Spectrograph first view on Solar Spicules

    OpenAIRE

    Pereira, T. M. D.; de Pontieu, B.; Carlsson, M; Hansteen, V.; Tarbell, T. D.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.; Wülser, J. P.; Martínez-Sykora, J.; Kleint, L.; Golub, L.; McKillop, S.; Reeves, K. K.

    2014-01-01

    Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere remains unknown. Here we give a first glimpse of what quiet Sun spicules look like when observed with NASA's recently launched Interface Region Imaging Spectrograph (IRIS). Using IRIS spectra and filtergrams that sample the chromosphere and transition region we compare the ...

  9. The Software System for the AAO's HERMES Spectrograph

    Science.gov (United States)

    Shortridge, K.; Farrell, T.; Vuong, M.; Birchall, M.; Heald, R.

    2013-10-01

    The AAO's HERMES spectrograph will start operation in 2013. Its primary project will be a Galactic Archaeology survey that aims to reconstruct the early history of our Galaxy through precise measurements of the chemical abundances of one million stars. This paper describes some of the software aspects of the HERMES project: how it has evolved from the earlier AAO 2dF system, the extensive use of simulation for testing, the overall observing system, and the data reduction pipeline.

  10. CAFE: Calar Alto Fiber-fed Echelle spectrograph

    CERN Document Server

    Aceituno, J; Grupp, F; Lillo, J; Hernan-Obispo, M; Benitez, D; Montoya, L M; Thiele, U; Pedraz, S; Barrado, D; Dreizler, S; Bean, J

    2013-01-01

    We present here CAFE, the Calar Alto Fiber-fed Echelle spectrograph, a new instrument built at the Centro Astronomico Hispano Alem\\'an (CAHA). CAFE is a single fiber, high-resolution ($R\\sim$70000) spectrograph, covering the wavelength range between 3650-9800\\AA. It was built on the basis of the common design for Echelle spectrographs. Its main aim is to measure radial velocities of stellar objects up to $V\\sim$13-14 mag with a precision as good as a few tens of $m s^{-1}$. To achieve this goal the design was simplified at maximum, removing all possible movable components, the central wavelength is fixed, so the wavelentgth coverage; no filter wheel, one slit and so on, with a particular care taken in the thermal and mechanical stability. The instrument is fully operational and publically accessible at the 2.2m telescope of the Calar Alto Observatory. In this article we describe (i) the design, summarizing its manufacturing phase; (ii) characterize the main properties of the instrument; (iii) describe the red...

  11. Space and time resolving spectrograph for fusion plasma diagnostics

    International Nuclear Information System (INIS)

    This paper discusses construction of an EUV (60-350 angstrom) space and time resolving, grazing incidence spectrograph (STRS). The simultaneous spectral coverage of the instrument ranges from 20 to 60 angstrom, depending on the wavelength region. The spectral resolution is about 1 angstrom. The spectral resolution, accomplished by using the pinhole camera effect and the inherent astigmatism of a concave grating in grazing incidence, is about 2 m, with a total field of view of 60 cm at a distance of 2 cm from the plasma. The detector consists of a 75 mm MCP image intensifier optically coupled to three CCD area array detectors. Time resolution of up to 2 ms is achieved with high speed read-out electronics. A PDP 11.73 minicomputer controls the spectrograph and collects and reduces 3.0 MB of data per shot. The complete design of the STRS and the results of initial tests of the detector system, spectrograph, and data handling software are presented

  12. Career situation of female astronomers in Germany

    CERN Document Server

    Fohlmeister, J; 10.1002/asna.201211656

    2012-01-01

    We survey the job situation of women in astronomy in Germany and of German women abroad and review indicators for their career development. Our sample includes women astronomers from all academic levels from doctoral students to professors, as well as female astronomers who have left the field. We find that networking and human support are among the most important factors for success. Experience shows that students should carefully choose their supervisor and collect practical knowledge abroad. We reflect the private situation of female German astronomers and find that prejudices are abundant, and are perceived as discriminating.We identify reasons why women are more likely than men to quit astronomy after they obtain their PhD degree. We give recommendations to young students on what to pay attention to in order to be on the successful path in astronomy.

  13. Thirteenth Joint European and National Astronomical Meeting

    CERN Document Server

    Iniesta, J C

    2006-01-01

    The book gathers the invited talks to the XIII JENAM conference, organized this time by the European Astronomical Society (EAS) and the Spanish Astronomical Society (SEA), and hosted by the Instituto de Astrofísica de Andalucía (CSIC). All branches of astrophysics are encompassed from the largest scales and cosmology to the solar system and the Sun, through the galaxies and the stars, including a section on astronomical instrumentation. Very relevant experts from all over the world speak in a single book about the most recent, exciting results from their fields in a way which is useful for both researchers in these fields and colleagues working in other disciplines. The book is accompanied by a CD-ROM including the remaining contributions of the meeting in PDF format, hence opening a wide panorama of what is going on in astrophysics nowadays.

  14. Decoding the mechanisms of Antikythera astronomical device

    CERN Document Server

    Lin, Jian-Liang

    2016-01-01

    This book presents a systematic design methodology for decoding the interior structure of the Antikythera mechanism, an astronomical device from ancient Greece. The historical background, surviving evidence and reconstructions of the mechanism are introduced, and the historical development of astronomical achievements and various astronomical instruments are investigated. Pursuing an approach based on the conceptual design of modern mechanisms and bearing in mind the standards of science and technology at the time, all feasible designs of the six lost/incomplete/unclear subsystems are synthesized as illustrated examples, and 48 feasible designs of the complete interior structure are presented. This approach provides not only a logical tool for applying modern mechanical engineering knowledge to the reconstruction of the Antikythera mechanism, but also an innovative research direction for identifying the original structures of the mechanism in the future. In short, the book offers valuable new insights for all...

  15. Making Access to Astronomical Software More Efficient

    CERN Document Server

    Grosbol, P

    2010-01-01

    Access to astronomical data through archives and VO is essential but does not solve all problems. Availability of appropriate software for analyzing the data is often equally important for the efficiency with which a researcher can publish results. A number of legacy systems (e.g. IRAF, MIDAS, Starlink, AIPS, Gipsy), as well as others now coming online are available but have very different user interfaces and may no longer be fully supported. Users may need multiple systems or stand-alone packages to complete the full analysis which introduces significant overhead. The OPTICON Network on `Future Astronomical Software Environments' and the USVAO have discussed these issues and have outlined a general architectural concept that solves many of the current problems in accessing software packages. It foresees a layered structure with clear separation of astronomical code and IT infrastructure. By relying on modern IT concepts for messaging and distributed execution, it provides full scalability from desktops to cl...

  16. Beam Calibration of Radio Telescopes with Drones

    Science.gov (United States)

    Chang, Chihway; Monstein, Christian; Refregier, Alexandre; Amara, Adam; Glauser, Adrian; Casura, Sarah

    2015-11-01

    We present a multifrequency far-field beam map for the 5-m dish telescope at the Bleien Observatory measured using a commercially available drone. We describe the hexacopter drone used in this experiment, the design of the flight pattern, and the data analysis scheme. This is the first application of this calibration method to a single-dish radio telescope in the far-field. The high signal-to-noise ratio data allows us to characterize the beam pattern with high accuracy out to at least the fourth side-lobe. The resulting two-dimensional beam pattern is compared with that derived from a more traditional calibration approach using an astronomical calibration source. We discuss the advantages of this method compared to other beam calibration methods. Our results show that this drone-based technique is very promising for ongoing and future radio experiments, where the knowledge of the beam pattern is key to obtaining high-accuracy cosmological and astronomical measurements.

  17. Beam calibration of radio telescopes with drones

    CERN Document Server

    Chang, Chihway; Refregier, Alexandre; Amara, Adam; Glauser, Adrian; Casura, Sarah

    2015-01-01

    We present a multi-frequency far-field beam map for the 5m dish telescope at the Bleien Observatory measured using a commercially available drone. We describe the hexacopter drone used in this experiment, the design of the flight pattern, and the data analysis scheme. This is the first application of this calibration method to a single dish radio telescope in the far-field. The high signal-to-noise data allows us to characterise the beam pattern with high accuracy out to at least the 4th side-lobe. The resulting 2D beam pattern is compared with that derived from a more traditional calibration approach using an astronomical calibration source. We discuss the advantages of this method compared to other beam calibration methods. Our results show that this drone-based technique is very promising for ongoing and future radio experiments, where the knowledge of the beam pattern is key to obtaining high-accuracy cosmological and astronomical measurements.

  18. Water-Powered Astronomical Clock Tower

    Science.gov (United States)

    Sun, Xiaochun

    The construction of water-powered astronomical instruments was a long tradition of instrument making that started in the second century AD with Zhang Heng's water-powered celestial globe. The technology reached a peak when, in the eleventh century, Su Song and his team constructed the Water-Powered Astronomical Clock Tower which combined the armillary sphere, the celestial globe, and the time-keeping mechanism into a large automatic structure. Su Song's instrument contained a mechanism for controlling the water-powered movements of its wheels that amounts to an "escapement mechanism" for a mechanical clock. A new reconstruction of the mechanism is introduced in this chapter.

  19. A Novel Semantic Software for Astronomical Concepts

    CERN Document Server

    Heydari-Malayeri, M; Petit, F Le

    2012-01-01

    We have created a new semantic tool called AstroConcepts, providing definitions of astronomical concepts present on Web pages. This tool is a Google Chrome plug-in that interrogates the Etymological Dictionary of Astronomy and Astrophysics, developed at Paris Observatory. Thanks to this tool, if one selects an astronomical concept on a web page, a pop-up window will display the definition of the available English or French terms. Another expected use of this facility could be its implementation in Virtual Observatory services.

  20. The innermost astronomical unit of protoplanetary disks

    CERN Document Server

    Kluska, J; Benisty, M

    2016-01-01

    Circumstellar disks around young stars are the birthsites of planets. It is thus fundamental to study the disks in which they form, their structure and the physical conditions therein. The first astronomical unit is of great interest because this is where the terrestrial-planets form and the angular momentum is controled via massloss through winds/jets. With its milli-arcsecond resolution, optical interferometry is the only technic able to spatially resolve the first few astronomical units of the disk. In this review, we will present a broad overview of studies of young stellar objects with interferometry, and discuss prospects for the future.

  1. The near infrared camera for the Subaru Prime Focus Spectrograph

    Science.gov (United States)

    Smee, Stephen A.; Gunn, James E.; Golebiowski, Mirek; Barkhouser, Robert; Vivès, Sebastien; Pascal, Sandrine; Carr, Michael; Hope, Stephen C.; Loomis, Craig; Hart, Murdock; Sugai, Hajime; Tamura, Naoyuki; Shimono, Atsushi

    2014-08-01

    We present the detailed design of the near infrared camera for the SuMIRe (Subaru Measurement of Images and Redshifts) Prime Focus Spectrograph (PFS) being developed for the Subaru Telescope. The PFS spectrograph is designed to collect spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm - 1.26 μm. The spectrograph is comprised of four identical spectrograph modules, with each module collecting roughly 600 spectra from a robotic fiber positioner at the telescope prime focus. Each spectrograph module will have two visible channels covering wavelength ranges 380 nm - 640 nm and 640 nm - 955 nm, and one near infrared (NIR) channel with a wavelength range 955 nm - 1.26 μm. Dispersed light in each channel is imaged by a 300 mm focal length, f/1.07, vacuum Schmidt camera onto a 4k x 4k, 15 µm pixel, detector format. For the NIR channel a HgCdTe substrate-removed Teledyne 1.7 μm cutoff device is used. In the visible channels, CCDs from Hamamatsu are used. These cameras are large, having a clear aperture of 300 mm at the entrance window, and a mass of ~ 250 kg. Like the two visible channel cameras, the NIR camera contains just four optical elements: a two-element refractive corrector, a Mangin mirror, and a field flattening lens. This simple design produces very good imaging performance considering the wide field and wavelength range, and it does so in large part due to the use of a Mangin mirror (a lens with a reflecting rear surface) for the Schmidt primary. In the case of the NIR camera, the rear reflecting surface is a dichroic, which reflects in-band wavelengths and transmits wavelengths beyond 1.26 μm. This, combined with a thermal rejection filter coating on the rear surface of the second corrector element, greatly reduces the out-of-band thermal radiation that reaches the detector. The camera optics and detector are packaged in a cryostat and cooled by two Stirling cycle cryocoolers. The first corrector element serves as the

  2. Radio Astronomers Set New Standard for Accurate Cosmic Distance Measurement

    Science.gov (United States)

    1999-06-01

    estimate of the age of the universe. In order to do this, you need an unambiguous, absolute distance to another galaxy. We are pleased that the NSF's VLBA has for the first time determined such a distance, and thus provided the calibration standard astronomers have always sought in their quest for accurate distances beyond the Milky Way," said Morris Aizenman, Executive Officer of the National Science Foundation's (NSF) Division of Astronomical Sciences. "For astronomers, this measurement is the golden meter stick in the glass case," Aizenman added. The international team of astronomers used the VLBA to measure directly the motion of gas orbiting what is generally agreed to be a supermassive black hole at the heart of NGC 4258. The orbiting gas forms a warped disk, nearly two light-years in diameter, surrounding the black hole. The gas in the disk includes water vapor, which, in parts of the disk, acts as a natural amplifier of microwave radio emission. The regions that amplify radio emission are called masers, and work in a manner similar to the way a laser amplifies light emission. Determining the distance to NGC 4258 required measuring motions of extremely small shifts in position of these masers as they rotate around the black hole. This is equivalent to measuring an angle one ten-thousandth the width of a human hair held at arm's length. "The VLBA is the only instrument in the world that could do this," said Moran. "This work is the culmination of a 20-year effort at the Harvard Smithsonian Center for Astrophysics to measure distances to cosmic masers," said Irwin Shapiro, Director of that institution. Collection of the data for the NGC 4258 project was begun in 1994 and was part of Herrnstein's Ph.D dissertation at Harvard University. Previous observations with the VLBA allowed the scientists to measure the speed at which the gas is orbiting the black hole, some 39 million times more massive than the Sun. They did this by observing the amount of change in the

  3. ASTRONOMICAL OBSERVING SYSTEM OVER THE ELECTROMAGNETIC SPECTRUM

    Directory of Open Access Journals (Sweden)

    A. B. BHATTACHARYA,

    2010-09-01

    Full Text Available The astronomical instruments over the electromagnetic spectrum that had been brought towards perfection owing to sudden arrival of radio astronomy are outlined. Improved techniques of observations from space,in situ exploration of the solar system as well as the advent of computer technologies have directed lines of new possibilities, which have been critically examined.

  4. Astroquery: querying astronomical web forms and databases

    OpenAIRE

    Sipocz, Brigitta

    2016-01-01

    Astroquery is an Astropy affiliated package for a set of tools for querying astronomical web forms and databases. In this lightning talk I give an overview of the available services and the usage of the package including a live demo of a typical use case.

  5. Astroquery: querying astronomical web forms and databases

    Science.gov (United States)

    Sipocz, Brigitta

    2016-03-01

    Astroquery is an Astropy affiliated package for a set of tools for querying astronomical web forms and databases. In this lightning talk I give an overview of the available services and the usage of the package including a live demo of a typical use case.

  6. Astronomía en la cultura

    Science.gov (United States)

    López, A.; Giménez Benitez, S.; Fernández, L.

    La Astronomía en la Cultura es el estudio interdisciplinario a nivel global de la astronomía prehistórica, antigua y tradicional, en el marco de su contexto cultural. Esta disciplina abarca cualquier tipo de estudios o líneas de investigación en que se relacione a la astronomía con las ciencias humanas o sociales. En ella se incluyen tanto fuentes escritas, relatos orales como fuentes arqueológicas, abarcando entre otros, los siguientes temas: calendarios, observación práctica, cultos y mitos, representación simbólica de eventos, conceptos y objetos astronómicos, orientación astronómica de tumbas, templos, santuarios y centros urbanos, cosmología tradicional y la aplicación ceremonial de tradiciones astronómicas, la propia historia de la astronomía y la etnoastronomía (Krupp, 1989) (Iwaniszewski, 1994). En nuestro trabajo abordamos la historia y situación actual de esta disciplina, sus métodos y sus relaciones con otras áreas de investigación.

  7. Professional Astronomers in Service to the AAVSO

    Science.gov (United States)

    Saladyga, M.; Waagen, E. O.

    2012-06-01

    (Abstract only) Throughout its 100-year history, the American Association of Variable Star Observers (AAVSO) has welcomed professional astronomers to its membership ranks, and has encouraged their participation as organization leaders. The AAVSO has been fortunate to have over 60 distinguished professionals serve as officers (Directors, Presidents, Council), and as participants in its various scientific and organizational committees.

  8. astLib: Tools for research astronomers

    Science.gov (United States)

    Hilton, Matt; Boada, Steven

    2016-07-01

    astLib is a set of Python modules for performing astronomical plots, some statistics, common calculations, coordinate conversions, and manipulating FITS images with World Coordinate System (WCS) information through PyWCSTools, a simple wrapping of WCSTools (ascl:1109.015).

  9. The Virtual Astronomical Observatory Users Forum

    Science.gov (United States)

    Muench, August A.; Emery Bunn, S.; Astronomical Observatory, Virtual

    2013-01-01

    We present the online forum astrobabel.com, which has the goal of being a gathering place for the collective community intelligence about astronomical computing. The audience for this forum is anyone engaged in the analysis of astronomical or planetary data, whether that data be observational or theoretical. It is a free, community driven site where discussions are formulated primarily around the "question and answer" format. Current topics on the forum range from “Is there a photometry package in Python?” to “Where are the support forums for astronomy software packages?” and “Why is my SDSS SkyQuery query missing galaxies?” The poster will detail the full scope of discussions in the forum, and provide some basic guidelines for ensuring high quality forum posts. We will highlight the ways astronomers can discover and participate in discussions. Further, we view this as an excellent opportunity to gather feedback and feature requests from AAS221 attendees. Acknowledgement: The Virtual Astronomical Observatory (VAO) is managed by the VAO, LLC, a non-profit company established as a partnership of the Associated Universities, Inc. and the Association of Universities for Research in Astronomy, Inc. The VAO is sponsored by the National Science Foundation and the National Aeronautics and Space Administration.

  10. MOONS: A New Powerful Multi-Object Spectrograph for the VLT

    Science.gov (United States)

    Cirasuolo, M.; MOONS Consortium

    2016-10-01

    MOONS (the Multi-Object Optical and Near-infrared Spectrograph) is a third-generation instrument for the ESO Very Large Telescope (VLT). The large collecting area offered by the VLT (8.2 m diameter), combined with the large multiplex and wavelength coverage (optical to near-IR: 0.64 μm - 1.8 μm) of MOONS will provide the European astronomical community with a powerful, unique instrument able to pioneer a wide range of Galactic, Extragalactic and Cosmological studies, and the crucial follow-up for major facilities such as Gaia, VISTA, Euclid and LSST. MOONS has the observational power needed to unveil galaxy formation and evolution over the entire history of the Universe, from stars in our Milky Way, through the redshift desert, and up to the epoch of the very first galaxies and reionization of the Universe at redshifts of z > 8-9, just a few million years after the Big Bang. From five years of observations MOONS will provide high-quality spectra for >3 M stars in our Galaxy and the Local Group, and for 1-2 M galaxies at z >1 (for an SDSS-like survey), promising to revolutionize our understanding of the Universe. The baseline design consists of 1024 fibers, deployable over a field-of-view of ˜500 sq. arcmin, the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.64 μm - 1.8 μm with two spectral resolving power settings: in the medium-resolution mode (R˜4,000-6,000) the entire wavelength range is observed simultaneously, while the high-resolution mode will cover simultaneously selected sub-regions: one region with R˜9,000 near the Ca II triplet to measure stellar radial velocities, and part of the H-band at R˜20,000 for precision measurements of chemical abundances.

  11. Relativistic scaling of astronomical quantities and the system of astronomical units

    OpenAIRE

    Klioner, Sergei A.

    2005-01-01

    For relativistic modelling of high-accuracy astronomical data several time scales are used: barycentric and geocentric coordinate times, TCB and TCG, as well as two additional time scales, TDB and TT, that are defined as linear functions of TCB and TCG, respectively. The paper is devoted to a concise but still detailed explanation of the reasons and the implications of the relativistic scalings of astronomical quantities induced by the time scales TDB and TT. We consequently distinguish betwe...

  12. Astronomical Observing Conditions at Xinglong Observatory from 2007 to 2014

    Science.gov (United States)

    Zhang, Ji-Cheng; Ge, Liang; Lu, Xiao-Meng; Cao, Zi-Huang; Chen, Xu; Mao, Yong-Na; Jiang, Xiao-Jun

    2015-12-01

    Xinglong Observatory of the National Astronomical Observatories, Chinese Academy of Sciences (NAOC), is one of the major optical observatories in China, which hosts nine optical telescopes including the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and the 2.16 m reflector. Scientific research from these telescopes is focused on stars, galaxies, and exoplanets using multicolor photometry and spectroscopic observations. Therefore, it is important to provide the observing conditions of the site, in detail, to the astronomers for an efficient use of these facilities. In this article, we present the characterization of observing conditions at Xinglong Observatory based on the monitoring of meteorology, seeing and sky brightness during the period from 2007 to 2014. Meteorological data were collected from a commercial Automatic Weather Station (AWS), calibrated by China Meteorological Administration. Mean and median wind speed are almost constant during the period analyzed and ranged from 1.0 to 3.5 m s-1. However, high wind speed (>=15 m s-1) interrupts observations, mainly, during the winter and spring. Statistical analysis of air temperature showed the temperature difference between daytime and nighttime, which can be solved by opening the ventilation device and the slit of the dome at least 1 hr before observations. Analysis resulted in average percentage of photometric nights and spectroscopic nights are 32% and 63% per year, respectively. The distribution of photometric nights and spectroscopic nights has a significant seasonal tendency, worse in summer due to clouds, dust, and high humidity. Seeing measurements were obtained using the Differential Image Motion Monitor (DIMM). Mean and median values of seeing over 1 year are around 1.9'' and 1.7'', respectively. Eighty percent of nights with seeing values are below 2.6'', whereas the distribution peaks around 1.8''. The measurements of sky brightness are acquired from the Sky Quality Meter (SQM

  13. HIRES: the high resolution spectrograph for the E-ELT

    Science.gov (United States)

    Zerbi, F. M.; Bouchy, F.; Fynbo, J.; Maiolino, R.; Piskunov, N.; Rebolo Lopez, R.; Santos, N.; Strassmeier, K.; Udry, S.; Vanzi, L.; Riva, M.; Basden, A.; Boisse, I.; Bonfils, X.; Buscher, D.; Cabral, A.; Dimarcantonio, P.; Di Varano, I.; Henry, D.; Monteiro, M.; Morris, T.; Murray, G.; Oliva, Ernesto; Parry, I.; Pepe, F.; Quirrenbach, A.; Rasilla, J. L.; Rees, P.; Stempels, E.; Valenziano, L.; Wells, M.; Wildi, F.; Origlia, L.; Allende Prieto, C.; Chiavassa, A.; Cristiani, S.; Figueira, P.; Gustafsson, B.; Hatzes, A.; Haehnelt, M.; Heng, K.; Israelian, G.; Kochukhov, O.; Lovis, C.; Marconi, A.; Martins, C. J. A. P.; Noterdaeme, P.; Petitjean, P.; Puzia, T.; Queloz, D.; Reiners, A.; Zoccali, M.

    2014-08-01

    The current instrumentation plan for the E-ELT foresees a High Resolution Spectrograph conventionally indicated as HIRES. Shaped on the study of extra-solar planet atmospheres, Pop-III stars and fundamental physical constants, HIRES is intended to embed observing modes at high-resolution (up to R=150000) and large spectral range (from the blue limit to the K band) useful for a large suite of science cases that can exclusively be tackled by the E-ELT. We present in this paper the solution for HIRES envisaged by the "HIRES initiative", the international collaboration established in 2013 to pursue a HIRES on E-ELT.

  14. CCD readout electronics for the Subaru Prime Focus Spectrograph

    Science.gov (United States)

    Hope, Stephen C.; Gunn, James E.; Loomis, Craig P.; Fitzgerald, Roger E.; Peacock, Grant O.

    2014-07-01

    The following paper details the design for the CCD readout electronics for the Subaru Telescope Prime Focus Spectrograph (PFS). PFS is designed to gather spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm to 1260 nm. The spectrograph is comprised of four identical spectrograph modules, each collecting roughly 600 spectra. The spectrograph modules provide simultaneous wavelength coverage over the entire band through the use of three separate optical channels: blue, red, and near infrared (NIR). A camera in each channel images the multi-object spectra onto a 4k × 4k, 15 μm pixel, detector format. The two visible cameras use a pair of Hamamatsu 2k × 4k CCDs with readout provided by custom electronics, while the NIR camera uses a single Teledyne HgCdTe 4k × 4k detector and Teledyne's ASIC Sidecar to read the device. The CCD readout system is a custom design comprised of three electrical subsystems - the Back End Electronics (BEE), the Front End Electronics (FEE), and a Pre-amplifier. The BEE is an off-the-shelf PC104 computer, with an auxiliary Xilinx FPGA module. The computer serves as the main interface to the Subaru messaging hub and controls other peripheral devices associated with the camera, while the FPGA is used to generate the necessary clocks and transfer image data from the CCDs. The FEE board sets clock biases, substrate bias, and CDS offsets. It also monitors bias voltages, offset voltages, power rail voltage, substrate voltage and CCD temperature. The board translates LVDS clock signals to biased clocks and returns digitized analog data via LVDS. Monitoring and control messages are sent from the BEE to the FEE using a standard serial interface. The Pre-amplifier board resides behind the detectors and acts as an interface to the two Hamamatsu CCDs. The Pre-amplifier passes clocks and biases to the CCDs, and analog CCD data is buffered and amplified prior to being returned to the FEE. In this paper we describe the

  15. Design of the KOSMOS oil-coupled spectrograph camera lenses

    CERN Document Server

    O'Brien, Thomas P; Martini, Paul; Poczulp, Gary

    2014-01-01

    We present the design details of oil-coupled lens groups used in the KOSMOS spectrograph camera. The oil-coupled groups use silicone rubber O-rings in a unique way to accurately center lens elements with high radial and axial stiffness while also allowing easy assembly. The O-rings robustly seal the oil within the lens gaps to prevent oil migration. The design of an expansion diaphragm to compensate for differential expansion due to temperature changes is described. The issues of lens assembly, lens gap shimming, oil filling and draining, bubble mitigation, material compatibility, mechanical inspection, and optical testing are discussed.

  16. Optical design of a multi-resolution, single shot spectrograph

    CERN Document Server

    Henault, Francois

    2016-01-01

    Multi-object or integral field spectrographs are recognized techniques for achieving simultaneous spectroscopic observations of different or extended sky objects with a high multiplex factor. In this communication is described a complementary approach for realizing similar measurements under different spectral resolutions at the same time. We describe the basic principle of this new type of spectrometer, that is based on the utilization of an optical pupil slicer. An optical design inspired from an already studied instrument is then presented and commented for the sake of illustration. Technical issues about the pupil slicer and diffractive components are also discussed. We finally conclude on the potential advantages and drawbacks of the proposed system.

  17. The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

    OpenAIRE

    Larkin, James E.; Moore, Anna M.; Wright, Shelley A.; Wincentsen, James E.; Anderson, David; Chisholm, Eric M.; Dekany, Richard G.; Dunn, Jennifer S.; Ellerbroek, Brent L.; Hayano, Yutaka; Phillips, Andrew C.; Simard, Luc; Smith, Roger; Suzuki, Ryuji; Weber, Robert W.

    2016-01-01

    IRIS is a near-infrared (0.84 to 2.4 microns) integral field spectrograph and wide-field imager being developed for first light with the Thirty Meter (TMT). It mounts to the advanced optics (AO) system NFIRAOS and has integrated on-instrument wavefront sensors (OIWFS) to achieve diffraction-limited spatial resolution at wavelengths longer than 1 micron. With moderate spectral resolution (R ~4,000 - 8,000) and large bandpass over a continuous field of view, IRIS will open new opportunities in ...

  18. Video Cameras in the Ondrejov Flare Spectrograph Results and Prospects

    Science.gov (United States)

    Kotrc, P.

    Since 1991 video cameras have been widely used both in the image and in the spectral data acquisition of the Ondrejov Multichannel Flare Spectrograph. In addition to classical photographic data registration, this kind of detectors brought new possibilities, especially into dynamical solar phenomena observations and put new requirements on the digitization, archiving and data processing techniques. The unique complex video system consisting of four video cameras and auxiliary equipment was mostly developed, implemented and used in the Ondrejov observatory. The main advantages and limitations of the system are briefly described from the points of view of its scientific philosophy, intents and outputs. Some obtained results, experience and future prospects are discussed.

  19. The vacuum system of the Karlsruhe magnetic spectrograph 'Little John'

    International Nuclear Information System (INIS)

    The vacuum equipment of the magnetic spectrograph Little John is described. The system is characterized by the following special features: The sliding exit flange of the target chamber can be moved to the desired angle of observation without affecting the high vacuum. The pressure maintained is less by a factor of ten than the pressure in the incoming beam tubing. The vacuum system is divided into several separate pumping sections. Ground loops are strictly avoided. All actual states of relevance are fed back to the control panels. The vacuum installation is protected by hardware interlocking systems as well as by a real time program written in FORTRAN in cooperation with CAMAC interfacing. (orig.)

  20. Building a scalable global data processing pipeline for large astronomical photometric datasets

    CERN Document Server

    Doyle, Paul

    2015-01-01

    Astronomical photometry is the science of measuring the flux of a celestial object. Since its introduction, the CCD has been the principle method of measuring flux to calculate the apparent magnitude of an object. Each CCD image taken must go through a process of cleaning and calibration prior to its use. As the number of research telescopes increases the overall computing resources required for image processing also increases. Existing processing techniques are primarily sequential in nature, requiring increasingly powerful servers, faster disks and faster networks to process data. Existing High Performance Computing solutions involving high capacity data centres are complex in design and expensive to maintain, while providing resources primarily to high profile science projects. This research describes three distributed pipeline architectures, a virtualised cloud based IRAF, the Astronomical Compute Node (ACN), a private cloud based pipeline, and NIMBUS, a globally distributed system. The ACN pipeline proce...

  1. Public Perception of Astronomers: Revered, Reviled and Ridiculed

    OpenAIRE

    West, Michael J.

    2009-01-01

    Society's view of astronomers has changed over time and from culture to culture. This review discusses some of the many ways that astronomers have been perceived by their societies and suggests ways that astronomers can influence public perception of ourselves and our profession in the future.

  2. Imaging Spectrograph as a Tool to Enhance the Undergraduate Student Research Experience

    Science.gov (United States)

    Williams, B.; Nielsen, K.; Johnson, S.

    2015-12-01

    Undergraduate students often engage in research activities that are part of a larger project outlined by research faculty, while it is less common for students to explore and define their own research project. The later has been shown to have tremendous impact on the learning outcome of the students and provide a stronger sense of pride and ownership of the research project. It is unrealistic to expect starting undergraduate students to define transformative research projects. However, with the proper training and guidance student-driven transformative research is possible for upper division students. We have instituted a student research paradigm with focus on the development of student research skills in coordination with their course progress. We present here a specific student project that engage students in aeronomy research activities and provide them with a solid base to establish their own research projects for senior year. The core of the project is an imaging spectrograph, which is constructed, tested, and calibrated by the students. The instrument provides unique opportunities student research projects across subject such as optics, quantum mechanics, and how these subjects are applied in the geosciences of aeronomy and space physics.

  3. X-shooter near infra-red spectrograph cryogenic design

    Science.gov (United States)

    Roelfsema, Ronald; Albers, Peter; Lizon, Jean-Louis; van Dael, Pieter; Elswijk, Eddy; Groot, Paul; Hanenburg, Hiddo; Kragt, Jan; Navarro, Ramon; Tromp, Niels; Wulterkens, Gerben

    2008-07-01

    X-shooter is a high-efficiency spectrograph capable of simultaneously observing the complete spectral range of 300- 2500 nm. The instrument will be located at the Cassegrain focus of one of the VLT UTs. To allow sky back ground limited observations the 120 kg Optical Bench of the NIR Spectrograph and the HAWAII-2RG detector are cooled to 105 K and 82 K respectively. To ensure vibrationless operation the cooling is performed by a LN2 bath-cryostat. The thermal stability requirements for the Optical Box are very tight (order of 100 mK) considering that the NIR-cryostat is subject to telescope movement and LN2 level variations. Large glass optics are limiting the cooldown. To speed up the cooldown the cooling concept of the Optical Box includes the utilization of LN2 heat exchangers. To avoid asymptotic stabilizing times the Optical Box is cooled below the operating temperature. When the optics reach a temperature slightly above the operating temperature the temperature of the Optical Box is quickly brought back to stabilize the optics. Dedicated controllers, strapping and heaters are used for temperature stabilization during steady state. A cryostat hold time of 24 hours with the minimum amount of LN2 in view of the tight mass budget requires strict control of the power budget and careful control of the design margins. This is ensured by precise modeling of the temperature behavior. The thermal model is compared with the actual measured thermal behavior.

  4. The Wide Field Spectrograph (WiFeS)

    CERN Document Server

    Dopita, Michael; McGregor, Peter; Oates, Patrick; Bloxham, Gabe; Jones, Damien

    2007-01-01

    This paper describes the Wide Field Spectrograph (WiFeS) under construction at the Research School of Astronomy and Astrophysics (RSAA) of the Australian National University (ANU) for the ANU 2.3m telescope at the Siding Spring Observatory. WiFeS is a powerful integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent thoughput, wavelength stability, spectrophotometric performance and superb image quality along with wide spectral coverage throughout the 320-950 nm wavelength region. It provides a 25x38 arcsec. field with 0.5 arcsec. sampling along each of twenty five 38X1 arcsec slitlets. The output format is optimized to match the 4096x4096 pixel CCD detectors in each of two cameras individually optimized for the blue and the red ends of the spectrum, respectively. A process of "interleaved nod-and-shuffle" will be applied to permit quantum noise-limited sky subtraction. Using VPH gratings, spectral resolutions of 3000 and 7000 are provided. The full spectral range is c...

  5. Initial results from the fast imaging solar spectrograph (FISS)

    CERN Document Server

    2015-01-01

    This collection of papers describes the instrument and initial results obtained from the Fast Imaging Solar Spectrograph (FISS),  one of the post-focus instruments of the 1.6 meter New Solar Telescope at the Big Bear Solar Observatory. The FISS primarily aims at investigating structures and dynamics of  chromospheric features. This instrument is a dual-band Echelle spectrograph optimized for the simultaneous recording of the H I 656.3 nm band and the Ca II 854.2 nm band. The imaging is done with the fast raster scan realized by the linear motion of a two-mirror scanner, and its quality is determined by the performance of the adaptive optics of the telescope.    These papers illustrate the capability of the early FISS observations in the study of chromospheric features. Since the imaging quality has been improved a lot with the advance of the adaptive optics, one can obtain much better data with the current FISS observations.        This volume is aimed at graduate students and researchers working in...

  6. The Infrared Imaging Spectrograph (IRIS) for TMT: Data Reduction System

    CERN Document Server

    Walth, Gregory; Weiss, Jason; Larkin, James E; Moore, Anna M; Chapin, Edward L; Do, Tuan; Dunn, Jennifer; Ellerbroek, Brent; Gillies, Kim; Hayano, Yutaka; Johnson, Chris; Marshall, Daniel; Riddle, Reed L; Simard, Luc; Sohn, Ji Man; Suzuki, Ryuji; Wincensten, James

    2016-01-01

    IRIS (InfraRed Imaging Spectrograph) is the diffraction-limited first light instrument for the Thirty Meter Telescope (TMT) that consists of a near-infrared (0.84 to 2.4 $\\mu$m) imager and integral field spectrograph (IFS). The IFS makes use of a lenslet array and slicer for spatial sampling, which will be able to operate in 100's of different modes, including a combination of four plate scales from 4 milliarcseconds (mas) to 50 mas with a large range of filters and gratings. The imager will have a field of view of 34$\\times$34 arcsec$^{2}$ with a plate scale of 4 mas with many selectable filters. We present the preliminary design of the data reduction system (DRS) for IRIS that need to address all of these observing modes. Reduction of IRIS data will have unique challenges since it will provide real-time reduction and analysis of the imaging and spectroscopic data during observational sequences, as well as advanced post-processing algorithms. The DRS will support three basic modes of operation of IRIS; reduc...

  7. Prime Focus Instrument of Prime Focus Spectrograph for Subaru Telescope

    CERN Document Server

    Wang, Shiang-Yu; Schwochert, Mark A; Huang, Pin-Jie; Kimura, Masahiko; Chen, Hsin-Yo; Reiley, Dan J; Mao, Peter; Fisher, Charles D; Tamura, Naoyuki; Chang, Yin-Chang; Hu, Yen-Sang; Ling, Hung-Hsu; Wen, Chih-Yi; Chou, Richard C -Y; Takato, Naruhisa; Sugai, Hajime; Ohyama, Youichi; Karoji, Hiroshi; Shimono, Atsushi; Ueda, Akitoshi

    2014-01-01

    The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph design for the prime focus of the 8.2m Subaru telescope. PFS will cover 1.3 degree diameter field with 2394 fibers to complement the imaging capability of Hyper SuprimeCam (HSC). The prime focus unit of PFS called Prime Focus Instrument (PFI) provides the interface with the top structure of Subaru telescope and also accommodates the optical bench in which Cobra fiber positioners are located. In addition, the acquisition and guiding (A&G) cameras, the optical fiber positioner system, the cable wrapper, the fiducial fibers, illuminator, and viewer, the field element, and the telemetry system are located inside the PFI. The mechanical structure of the PFI was designed with special care such that its deflections sufficiently match those of the HSC Wide Field Corrector (WFC) so the fibers will stay on targets over the course of the observations within the required accuracy.

  8. Metrology Camera System of Prime Focus Spectrograph for Subaru Telescope

    CERN Document Server

    Wang, Shiang-Yu; Huang, Pin-Jie; Ling, Hung-Hsu; Karr, Jennifer; Chang, Yin-Chang; Hu, Yen-Shan; Hsu, Shu-Fu; Chen, Hsin-Yo; Gunn, James E; Reiley, Dan J; Tamura, Naoyuki; Takato, Naruhisa; Shimono, Atsushi

    2016-01-01

    The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS will cover a 1.3 degree diameter field with 2394 fibers to complement the imaging capabilities of Hyper SuprimeCam. To retain high throughput, the final positioning accuracy between the fibers and observing targets of PFS is required to be less than 10um. The metrology camera system (MCS) serves as the optical encoder of the fiber motors for the configuring of fibers. MCS provides the fiber positions within a 5um error over the 45 cm focal plane. The information from MCS will be fed into the fiber positioner control system for the closed loop control. MCS will be located at the Cassegrain focus of Subaru telescope in order to to cover the whole focal plane with one 50M pixel Canon CMOS camera. It is a 380mm Schmidt type telescope which generates a uniform spot size with a 10 micron FWHM across the field for reasonable sampling of PSF. Carbon fiber tubes are ...

  9. Stratospheric NO2 Concentration Determined by DOAS Using Compact Spectrographs

    Science.gov (United States)

    Raponi, Marcelo M.; Wolfram, Elian; Rinaldi, Horacio; Rosales, Alejandro; Quel, Eduardo J.; Tocho, Jorge O.

    2008-04-01

    In this work we present the results for stratospheric NO2-total column concentration retrieved by DOAS (Differential Optical Absorption Spectroscopy) performed with compact spectrographs. The behavior for three different spectrographs (MonoSpec 27, Jarrell-Ash; HR4000, Ocean Optics and Mechelle 900, Multichannel Instruments) are analyzed making one intercomparison in the facilities of the LIDAR Division of CEILAP (CITEFA—CONICET), in Villa Martelli, Argentina (34.5° S, 58.5° W, 20 m amsl). The three instruments have a similar resolution (approximately 0.1 nm) but operate with different optical configurations and have optical sensors of different characteristics; two of them have cooling capability and the other one (HR4000) operates at room temperature. The NO2 concentration was obtained from spectral results at twilight using solar noon spectra as reference. In all cases zenithal diffuse irradiance was used. The NO2 absorption cross section given by S. Voigt and J. P. Burrows (University of Bremen—Institute of Environmental Physics) corresponding to 223 °K and 100 mbar is used. Results are compared with public data corresponding to ground-based device or to instruments mounted in satellites. These atmospheric soundings are of extreme importance to understand the roll that plays the stratospheric NO2 in the associated phenomena of destruction and formation of ozone in the low stratosphere at middle latitudes.

  10. Revista Mexicana de Astronomía y Astrofísica, a real option for astronomical publication

    Science.gov (United States)

    Torres-Peimbert, S.; Allen, C.

    2011-10-01

    We present statistical data about the Revista Mexicana de Astronomía y Astrofísica. We consider that this journal is well positioned in the international astronomical literature. Similarly we present information about the Serie de Conferencias, which also has a wide level of acceptance by the astronomical community.

  11. Identifying seasonal stars in Kaurna astronomical traditions

    Science.gov (United States)

    Hamacher, Duane W.

    2015-03-01

    Early ethnographers and missionaries recorded Aboriginal languages and oral traditions across Australia. Their general lack of astronomical training resulted in misidentifications, transcription errors and omissions in these records. In western Victoria and southeast South Australia many astronomical traditions were recorded but, cur- iously, some of the brightest stars in the sky were omitted. Scholars claimed these stars did not feature in Aboriginal traditions. This continues to be repeated in the literature, but current research shows that these stars may in fact feature in Aboriginal traditions and could be seasonal calendar markers. This paper uses established techniques to identify seasonal stars in the traditions of the Kaurna Aboriginal people of the Adelaide Plains, South Australia.

  12. Statistical methods for astronomical data analysis

    CERN Document Server

    Chattopadhyay, Asis Kumar

    2014-01-01

    This book introduces “Astrostatistics” as a subject in its own right with rewarding examples, including work by the authors with galaxy and Gamma Ray Burst data to engage the reader. This includes a comprehensive blending of Astrophysics and Statistics. The first chapter’s coverage of preliminary concepts and terminologies for astronomical phenomenon will appeal to both Statistics and Astrophysics readers as helpful context. Statistics concepts covered in the book provide a methodological framework. A unique feature is the inclusion of different possible sources of astronomical data, as well as software packages for converting the raw data into appropriate forms for data analysis. Readers can then use the appropriate statistical packages for their particular data analysis needs. The ideas of statistical inference discussed in the book help readers determine how to apply statistical tests. The authors cover different applications of statistical techniques already developed or specifically introduced for ...

  13. International Astronomical Union Sympoisum No.50

    CERN Document Server

    Westerlund, B

    1973-01-01

    Dr J. Landi Dessy, Director of the Astronomical Observatory, Cordoba, Argentina, invited the International Astronomical Union to hold a Symposium in Cordoba in connection with the celebration of the Centennial of the Cordoba Observatory; the date of foundation is October 24, 1871. He proposed that the Symposium should deal with Spectral Classification and Multicolour Photometry as seven years had elapsed since the Symposium No. 24 in Saltsj6baden, and much development had occurred in the field. The invitation and the proposal were accepted by the IAU, and the Symposium was held in Villa Carlos Paz, near Cordoba, between October 18 and October 24, 1971. It was attended by about 50 scientists representing Argentina, Canada, Chile, Den­ mark, France, Germany, Italy, Mexico, Sweden, Switzerland, U.K., U.S.A., Vatican City State and Venezuela. The Symposium was divided into four sessions: 1. Classification of slit spectra, 2. Classification of objective-prism spectra, 3. Photometric classification, 4. Catalogues ...

  14. Carriers of the astronomical 2175 ? extinction feature

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J; Dai, Z; Ernie, R; Browning, N; Graham, G; Weber, P; Smith, J; Hutcheon, I; Ishii, H; Bajt, S; Floss, C; Stadermann, F

    2004-07-20

    The 2175 {angstrom} extinction feature is by far the strongest spectral signature of interstellar dust observed by astronomers. Forty years after its discovery the origin of the feature and the nature of the carrier remain controversial. The feature is enigmatic because although its central wavelength is almost invariant its bandwidth varies strongly from one sightline to another, suggesting multiple carriers or a single carrier with variable properties. Using a monochromated transmission electron microscope and valence electron energy-loss spectroscopy we have detected a 5.7 eV (2175 {angstrom}) feature in submicrometer-sized interstellar grains within interplanetary dust particles (IDPs) collected in the stratosphere. The carriers are organic carbon and amorphous silicates that are abundant and closely associated with one another both in IDPs and in the interstellar medium. Multiple carriers rather than a single carrier may explain the invariant central wavelength and variable bandwidth of the astronomical 2175 {angstrom} feature.

  15. Recruitment and Retention of LGBTIQ Astronomers

    Science.gov (United States)

    Dixon, William Van Dyke

    2012-01-01

    While lesbian, gay, bisexual, transgender, intersex, or questioning (LGBTIQ) astronomers face many of the same workplace challenges as women and racial/ethnic minorities, from implicit bias to overt discrimination, other challenges are unique to this group. An obvious example is the absence at many institutions of health insurance and other benefits for the same-sex domestic partners of their employees. More subtle is the psychological toll paid by LGBTIQ astronomers who remain "in the closet," self-censoring every statement about their personal lives. Paradoxically, the culture of the physical sciences, in which sexuality, gender identity, and gender expression are considered irrelevant, can discourage their discussion, further isolating LGBTIQ researchers. Addressing these challenges is not just a matter of fairness; it is an essential tool in the recruitment and retention of the brightest researchers and in assuring their productivity. We will discuss these issues and what individuals and departments can to make their institutions more welcoming to their LGBTIQ colleagues.

  16. Extracting Knowledge From Massive Astronomical Data Sets

    CERN Document Server

    Brescia, Massimo; Djorgovski, S G; Donalek, Ciro; Longo, Giuseppe; Paolillo, Maurizio

    2011-01-01

    The exponential growth of astronomical data collected by both ground based and space borne instruments has fostered the growth of Astroinformatics: a new discipline laying at the intersection between astronomy, applied computer science, and information and computation (ICT) technologies. At the very heart of Astroinformatics is a complex set of methodologies usually called Data Mining (DM) or Knowledge Discovery in Data Bases (KDD). In the astronomical domain, DM/KDD are still in a very early usage stage, even though new methods and tools are being continuously deployed in order to cope with the Massive Data Sets (MDS) that can only grow in the future. In this paper, we briefly outline some general problems encountered when applying DM/KDD methods to astrophysical problems, and describe the DAME (DAta Mining & Exploration) web application. While specifically tailored to work on MDS, DAME can be effectively applied also to smaller data sets. As an illustration, we describe two application of DAME to two di...

  17. Detecting Diffuse Sources in Astronomical Images

    CERN Document Server

    Butler-Yeoman, T; Hollitt, C P; Hogg, D W; Johnston-Hollitt, M

    2016-01-01

    We present an algorithm capable of detecting diffuse, dim sources of any size in an astronomical image. These sources often defeat traditional methods for source finding, which expand regions around points of high intensity. Extended sources often have no bright points and are only detectable when viewed as a whole, so a more sophisticated approach is required. Our algorithm operates at all scales simultaneously by considering a tree of nested candidate bounding boxes, and inverts a hierarchical Bayesian generative model to obtain the probability of sources existing at given locations and sizes. This model naturally accommodates the detection of nested sources, and no prior knowledge of the distribution of a source, or even the background, is required. The algorithm scales nearly linear with the number of pixels making it feasible to run on large images, and requires minimal parameter tweaking to be effective. We demonstrate the algorithm on several types of astronomical and artificial images.

  18. Division B Commission 6: Astronomical Telegrams

    Science.gov (United States)

    Yamaoka, H.; Green, D. W. E.; Samus, N. N.; Aksnes, K.; Gilmore, A. C.; Nakano, S.; Sphar, T.; Tichá, J.; Williams, G. V.

    2016-04-01

    IAU Commission 6 ``Astronomical Telegrams'' had a single business meeting during Honolulu General Assembly of the IAU. It took place on Tuesday, 11 August 2015. The meeting was attended by Hitoshi Yamaoka (President), Daniel Green (Director of the Central Bureau for Astronomical Telegrams, CBAT, via Skype), Steven Chesley (JPL), Paul Chodas (JPL), Alan Gilmore (Canterbury University), Shinjiro Kouzuma (Chukyo University), Paolo Mazzali (Co-Chair of the Supernova Working Group), Elena Pian (Scuola Normale Superiore di Pisa), Marion Schmitz (chair IAU Working Group Designations + NED), David Tholen (University of Hawaii), Jana Ticha (Klet Observatory), Milos Tichy (Klet Observatory), Giovanni Valsecchi (INAF\\slash Italy), Gareth Williams (Minor Planet Center). Apologies: Nikolai Samus (General Catalogue of Variable Stars, GCVS).

  19. Compression of interferometric radio-astronomical data

    CERN Document Server

    Offringa, A R

    2016-01-01

    The volume of radio-astronomical data is a considerable burden in the processing and storing of radio observations with high time and frequency resolutions and large bandwidths. Lossy compression of interferometric radio-astronomical data is considered to reduce the volume of visibility data and to speed up processing. A new compression technique named "Dysco" is introduced that consists of two steps: a normalization step, in which grouped visibilities are normalized to have a similar distribution; and a quantization and encoding step, which rounds values to a given quantization scheme using a dithering scheme. Several non-linear quantization schemes are tested and combined with different methods for normalizing the data. Four data sets with observations from the LOFAR and MWA telescopes are processed with different processing strategies and different combinations of normalization and quantization. The effects of compression are measured in image plane. The noise added by the lossy compression technique acts ...

  20. Astronomía Mocoví

    Science.gov (United States)

    López, A.; Giménez Benitez, S.; Fernández, L.

    El presente trabajo, es una revisión crítica de la astronomía en la cultura Mocoví, aportando a lo realizado previamente por Lehmann Nistche (Lehmann Nistche, 1924 y 1927) el resultado de nuestro trabajo de campo. Un mayor conocimiento de las cosmovisiones de las etnias de esta área es fundamental para una mejor comprensión de la dispersión de las ideas cosmológicas entre los pueblos aborígenes americanos, dada la importancia del corredor chaqueño como conexión entre las altas culturas andinas, la mesopotamia y la región pampeana (Susnik, 1972). Para ello se realiza una comparación con otras cosmovisiones del área americana. Nuestro aporte se enmarca dentro de las actuales líneas de trabajo mundialmente en desarrollo en Astronomía en la Cultura.

  1. Training the Next Generation of Astronomers

    CERN Document Server

    Williams, Peter K G; Maness, Holly; Modjaz, Maryam; Shapiro, Kristen L; Silverman, Jeffrey M; Strubbe, Linda; Adams, Betsey; Alatalo, Katherine; Chiu, Kuenley; Claire, Mark; Cobb, Bethany; Cruz, Kelle; Desroches, Louis-Benoit; Enoch, Melissa; Hull, Chat; Jang-Condell, Hannah; Law, Casey; McConnell, Nicholas; Meijerink, Rowin; Offner, Stella; Parejko, John K; Pober, Jonathan; Pontoppidan, Klaus; Poznanski, Dovi; Seth, Anil; Stahler, Steven; Walkowicz, Lucianne; West, Andrew A; Wetzel, Andrew; Whysong, David

    2009-01-01

    While both society and astronomy have evolved greatly over the past fifty years, the academic institutions and incentives that shape our field have remained largely stagnant. As a result, the astronomical community is faced with several major challenges, including: (1) the training that we provide does not align with the skills that future astronomers will need, (2) the postdoctoral phase is becoming increasingly demanding and demoralizing, and (3) our jobs are increasingly unfriendly to families with children. Solving these problems will require conscious engineering of our profession. Fortunately, this Decadal Review offers the opportunity to revise outmoded practices to be more effective and equitable. The highest priority of the Subcommittee on the State of the Profession should be to recommend specific, funded activities that will ensure the field meets the challenges we describe.

  2. Renewal Strings for Cleaning Astronomical Databases

    CERN Document Server

    Storkey, Amos J; Williams, Christopher K I; Mann, Robert G

    2014-01-01

    Large astronomical databases obtained from sky surveys such as the SuperCOSMOS Sky Surveys (SSS) invariably suffer from a small number of spurious records coming from artefactual effects of the telescope, satellites and junk objects in orbit around earth and physical defects on the photographic plate or CCD. Though relatively small in number these spurious records present a significant problem in many situations where they can become a large proportion of the records potentially of interest to a given astronomer. In this paper we focus on the four most common causes of unwanted records in the SSS: satellite or aeroplane tracks, scratches fibres and other linear phenomena introduced to the plate, circular halos around bright stars due to internal reflections within the telescope and diffraction spikes near to bright stars. Accurate and robust techniques are needed for locating and flagging such spurious objects. We have developed renewal strings, a probabilistic technique combining the Hough transform, renewal...

  3. Local sparse representation for astronomical image denoising

    Institute of Scientific and Technical Information of China (English)

    杨阿锋; 鲁敏; 滕书华; 孙即祥

    2013-01-01

    Motivated by local coordinate coding(LCC) theory in nonlinear manifold learning, a new image representation model called local sparse representation(LSR) for astronomical image denoising was proposed. Borrowing ideas from surrogate function and applying the iterative shrinkage-thresholding algorithm(ISTA), an iterative shrinkage operator for LSR was derived. Meanwhile, a fast approximated LSR method by first performing a K-nearest-neighbor search and then solving a l1optimization problem was presented under the guarantee of denoising performance. In addition, the LSR model and adaptive dictionary learning were incorporated into a unified optimization framework, which explicitly established the inner connection of them. Such processing allows us to simultaneously update sparse coding vectors and the dictionary by alternating optimization method. The experimental results show that the proposed method is superior to the traditional denoising method and reaches state-of-the-art performance on astronomical image.

  4. Bad pixel modified interpolation for astronomical images

    CERN Document Server

    Popowicz, A; Filus, Z

    2013-01-01

    We present a new method of interpolation for the pixel brightness estimation in astronomical images. Our new method is simple and easily implementable. We show the comparison of this method with the widely used linear interpolation and other interpolation algorithms using one thousand astronomical images obtained from the Sloan Digital Sky Survey. The comparison shows that our method improves bad pixels brightness estimation with four times lower mean error than the presently most popular linear interpolation and has a better performance than any other examined method. The presented idea is flexible and can be also applied to presently used and future interpolation methods. The proposed method is especially useful for large sky surveys image reduction but can be also applied to single image correction.

  5. Astronomical Image Denoising Using Dictionary Learning

    CERN Document Server

    Beckouche, Simon; Fadili, Jalal

    2013-01-01

    Astronomical images suffer a constant presence of multiple defects that are consequences of the intrinsic properties of the acquisition equipments, and atmospheric conditions. One of the most frequent defects in astronomical imaging is the presence of additive noise which makes a denoising step mandatory before processing data. During the last decade, a particular modeling scheme, based on sparse representations, has drawn the attention of an ever growing community of researchers. Sparse representations offer a promising framework to many image and signal processing tasks, especially denoising and restoration applications. At first, the harmonics, wavelets, and similar bases and overcomplete representations have been considered as candidate domains to seek the sparsest representation. A new generation of algorithms, based on data-driven dictionaries, evolved rapidly and compete now with the off-the-shelf fixed dictionaries. While designing a dictionary beforehand leans on a guess of the most appropriate repre...

  6. Atomic and Molecular Aspects of Astronomical Spectra

    CERN Document Server

    Sochi, Taha

    2012-01-01

    In the first section we present the atomic part where a C2+ atomic target was prepared and used to generate theoretical data to investigate recombination lines arising from electron-ion collisions in thin plasma. R-matrix method was used to describe the C2+ plus electron system. Theoretical data concerning bound and autoionizing states were generated in the intermediate-coupling approximation. The data were used to generate dielectronic recombination data for C+ which include transition lines, oscillator strengths, radiative transition probabilities, emissivities and dielectronic recombination coefficients. The data were cast in a line list containing 6187 optically-allowed transitions which include many C II lines observed in astronomical spectra. This line list was used to analyze the spectra from a number of astronomical objects, mainly planetary nebulae, and identify their electron temperature. The electron temperature investigation was also extended to include free electron energy analysis to investigate...

  7. Identifying seasonal stars in Kaurna astronomical traditions

    CERN Document Server

    Hamacher, Duane W

    2015-01-01

    Early ethnographers and missionaries recorded Aboriginal languages and oral traditions across Australia. Their general lack of astronomical training resulted in misidentifications, transcription errors, and omissions in these records. Additionally, many of these early records are fragmented. In western Victoria and southeast South Australia, many astronomical traditions were recorded, but curiously, some of the brightest stars in the sky were omitted. Scholars claimed these stars did not feature in Aboriginal traditions. This under-representation continues to be repeated in the literature, but current research shows that some of these stars may in fact feature in Aboriginal traditions and could be seasonal calendar markers. This paper uses established techniques in cultural astronomy to identify seasonal stars in the traditions of the Kaurna Aboriginal people of the Adelaide Plains, South Australia.

  8. The la Plata Astronomical Data Center

    Science.gov (United States)

    Marraco, H. G.

    1990-11-01

    RESUMEN. El Centro de Datos Astron6micos tiene su sede en la Facuitad de Ciencias Astron6micas y Geofisicas d la Universidad Nacional de La Plata y funciona por convenio entre esta facultad y el Centre des Stellaires de la Universite' Louis Pasteur en Estrasburgo (CDS), Francia. La finalidad de este centro es la de proveer a los astr6nomos del area con copias de los alrededor de 500 acumulados y/o preparados por el CDS a la vez que promover la producci6n y/o acumulaci6n de en el rea. Para la realizaci6n de esta tarea se cuenta con el apoyo del Centro Superior para el Procesamiento de la Informaci6n (CESPI) de la UNLP cuyos equipos se describen. Las tareas que se estan realizando incluyen la distribuci6n de SIMBAD a los astr6nomos argentinos y se efectuan ensayos de distribuci6n en linea de CD-ROM TEST DISK del Astronomical Data Center (ADC) de la NASA que contiene los 31 mas solicitados por los astr6nomos de todo el mundo. ABSTRACl The La Plata Astronomical Data Center operates by an agreement between the Facultad de Ciencias Astron6micas y Geofisicas at La Plata University and the Centre des Donnees Stellaires of Louis Pasteur University at Strasbourg (CDS), France. The purpose of the Center is to provide to the area astronomers with copies of the catalogs they need amongst those stored and/or prepared at CDS. At the same time the center will act of the astronomical data produced within its area. K words: DATA ANALYSIS

  9. Astronomy Legacy Project - Pisgah Astronomical Research Institute

    Science.gov (United States)

    Barker, Thurburn; Castelaz, Michael W.; Rottler, Lee; Cline, J. Donald

    2016-01-01

    Pisgah Astronomical Research Institute (PARI) is a not-for-profit public foundation in North Carolina dedicated to providing hands-on educational and research opportunities for a broad cross-section of users in science, technology, engineering and math (STEM) disciplines. In November 2007 a Workshop on a National Plan for Preserving Astronomical Photographic Data (2009ASPC,410,33O, Osborn, W. & Robbins, L) was held at PARI. The result was the establishment of the Astronomical Photographic Data Archive (APDA) at PARI. In late 2013 PARI began ALP (Astronomy Legacy Project). ALP's purpose is to digitize an extensive set of twentieth century photographic astronomical data housed in APDA. Because of the wide range of types of plates, plate dimensions and emulsions found among the 40+ collections, plate digitization will require a versatile set of scanners and digitizing instruments. Internet crowdfunding was used to assist in the purchase of additional digitization equipment that were described at AstroPlate2014 Plate Preservation Workshop (www.astroplate.cz) held in Prague, CZ, March, 2014. Equipment purchased included an Epson Expression 11000XL scanner and two Nikon D800E cameras. These digital instruments will compliment a STScI GAMMA scanner now located in APDA. GAMMA will be adapted to use an electroluminescence light source and a digital camera with a telecentric lens to achieve high-speed high-resolution scanning. The 1μm precision XY stage of GAMMA will allow very precise positioning of the plate stage. Multiple overlapping CCD images of small sections of each plate, tiles, will be combined using a photo-mosaic process similar to one used in Harvard's DASCH project. Implementation of a software pipeline for the creation of a SQL database containing plate images and metadata will be based upon APPLAUSE as described by Tuvikene at AstroPlate2014 (www.astroplate.cz/programs/).

  10. Astronomical orientations in sanctuaries of Daunia

    CERN Document Server

    Antonello, E; Sisto, A M Tunzi; LoZupone, M

    2013-01-01

    Prehistoric sanctuaries of Daunia date back several thousand years. During the Neolithic and Bronze Age the farmers in that region dug hypogea and holes whose characteristics suggest a ritual use. In the present note we summarize the results of the astronomical analysis of the orientation of the row holes in three different sites, and we point out the possible use of the setting of the stars of Centaurus. An interesting archaeological confirmation of an archaeoastronomical prediction is also reported.

  11. Planar Integrated Optics and astronomical interferometry

    OpenAIRE

    Kern, Pierre; Berger, Jean-Philippe; Haguenauer, Pierre; Malbet, Fabien; Perraut, Karine

    2001-01-01

    16 pages Integrated optics (IO) is an optical technology that allows to reproduce optical circuits on a planar substrate. Since 1996, we have investigated the potentiality of IO in the framework of astronomical single mode interferometry. We review in this paper the principles of IO, the requirements for interferometry and the corresponding solutions offered by IO, the results of component characterization and the possible fields of application.

  12. An Astronomer's View of Climate Change

    CERN Document Server

    Morton, Donald C

    2014-01-01

    This paper describes some of the astronomical effects that could be important for understanding the ice ages, historic climate changes and the recent temperature increase. These include changes in the sun's luminosity, periodic changes in the earth's orbital parameters, the sun's orbit around our galaxy, the variability of solar activity and the anticorrelation of cosmic ray flux with that activity. Finally recent trends in solar activity and global temperatures are compared with the predictions of climate models.

  13. AWOB: A Collaborative Workbench for Astronomers

    Science.gov (United States)

    Kim, J. W.; Lemson, G.; Bulatovic, N.; Makarenko, V.; Vogler, A.; Voges, W.; Yao, Y.; Kiefl, R.; Koychev, S.

    2015-09-01

    We present the Astronomers Workbench (AWOB1), a web-based collaboration and publication platform for a scientific project of any size, developed in collaboration between the Max-Planck institutes of Astrophysics (MPA) and Extra-terrestrial Physics (MPE) and the Max-Planck Digital Library (MPDL). AWOB facilitates the collaboration between geographically distributed astronomers working on a common project throughout its whole scientific life cycle. AWOB does so by making it very easy for scientists to set up and manage a collaborative workspace for individual projects, where data can be uploaded and shared. It supports inviting project collaborators, provides wikis, automated mailing lists, calendars and event notification and has a built in chat facility. It allows the definition and tracking of tasks within projects and supports easy creation of e-publications for the dissemination of data and images and other resources that cannot be added to submitted papers. AWOB extends the project concept to larger scale consortia, within which it is possible to manage working groups and sub-projects. The existing AWOB instance has so far been limited to Max-Planck members and their collaborators, but will be opened to the whole astronomical community. AWOB is an open-source project and its source code is available upon request. We intend to extend AWOB's functionality also to other disciplines, and would greatly appreciate contributions from the community.

  14. GalileoMobile: Astronomical activities in schools

    Science.gov (United States)

    Dasi Espuig, Maria; Vasquez, Mayte; Kobel, Philippe

    GalileoMobile is an itinerant science education initiative run on a voluntary basis by an international team of astronomers, educators, and science communicators. Our team's main goal is to make astronomy accessible to schools and communities around the globe that have little or no access to outreach actions. We do this by performing teacher workshops, activities with students, and donating educational material. Since the creation of GalileoMobile in 2008, we have travelled to Chile, Bolivia, Peru, India, and Uganda, and worked with 56 schools in total. Our activities are centred on the GalileoMobile Handbook of Activities that comprises around 20 astronomical activities which we adapted from many different sources, and translated into 4 languages. The experience we gained in Chile, Bolivia, Peru, India, and Uganda taught us that (1) bringing experts from other countries was very stimulating for children as they are naturally curious about other cultures and encourages a collaboration beyond borders; (2) high-school students who were already interested in science were always very eager to interact with real astronomers doing research to ask for career advice; (3) inquiry-based methods are important to make the learning process more effective and we have therefore, re-adapted the activities in our Handbook according to these; (4) local teachers and university students involved in our activities have the potential to carry out follow-up activities, and examples are those from Uganda and India.

  15. AAS Publishing News: Astronomical Software Citation Workshop

    Science.gov (United States)

    Kohler, Susanna

    2015-07-01

    Do you write code for your research? Use astronomical software? Do you wish there were a better way of citing, sharing, archiving, or discovering software for astronomy research? You're not alone! In April 2015, AAS's publishing team joined other leaders in the astronomical software community in a meeting funded by the Sloan Foundation, with the purpose of discussing these issues and potential solutions. In attendance were representatives from academic astronomy, publishing, libraries, for-profit software sharing platforms, telescope facilities, and grantmaking institutions. The goal of the group was to establish “protocols, policies, and platforms for astronomical software citation, sharing, and archiving,” in the hopes of encouraging a set of normalized standards across the field. The AAS is now collaborating with leaders at GitHub to write grant proposals for a project to develop strategies for software discoverability and citation, in astronomy and beyond. If this topic interests you, you can find more details in this document released by the group after the meeting: http://astronomy-software-index.github.io/2015-workshop/ The group hopes to move this project forward with input and support from the broader community. Please share the above document, discuss it on social media using the hashtag #astroware (so that your conversations can be found!), or send private comments to julie.steffen@aas.org.

  16. David Gill - Magnificent and Desirable Astronomer

    CERN Document Server

    Reid, John S

    2016-01-01

    This paper was given to mark the centenary of the death of David Gill, the foremost British astronomer in the last quarter of the 19th century and into the 20th century. Gill abandoned a successful career as a clock and watchmaker. His speciality was in astrometry, an area of astronomy of both practical and scientific importance that tended to be eclipsed in the 20th century by the rise of astrophysics. As Her Majesty's Astronomer at the Cape of Good Hope for 27 years, David Gill was admired for his prolific contribution to highly accurate and trustworthy results. David Gill's collaboration was desired by leading astronomers of the day and he was the only southern hemisphere representative on the hugely important Conference Internationale des Etoiles Fondamentales of 1896. He created with Jacobus Kapetyn the first extensive star catalogue derived from photographic plates (the CPD), including over 450,000 stars. He was an initiator of the biggest multi-national and multi-observatory project of the century, tak...

  17. Astrobiology: An astronomer's perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bergin, Edwin A. [University of Michigan, Department of Astronomy, 500 Church Street, Ann Arbor, MI 48109 (United States)

    2014-12-08

    In this review we explore aspects of the field of astrobiology from an astronomical viewpoint. We therefore focus on the origin of life in the context of planetary formation, with additional emphasis on tracing the most abundant volatile elements, C, H, O, and N that are used by life on Earth. We first explore the history of life on our planet and outline the current state of our knowledge regarding the delivery of the C, H, O, N elements to the Earth. We then discuss how astronomers track the gaseous and solid molecular carriers of these volatiles throughout the process of star and planet formation. It is now clear that the early stages of star formation fosters the creation of water and simple organic molecules with enrichments of heavy isotopes. These molecules are found as ice coatings on the solid materials that represent microscopic beginnings of terrestrial worlds. Based on the meteoritic and cometary record, the process of planet formation, and the local environment, lead to additional increases in organic complexity. The astronomical connections towards this stage are only now being directly made. Although the exact details are uncertain, it is likely that the birth process of star and planets likely leads to terrestrial worlds being born with abundant water and organics on the surface.

  18. Astrobiology: An astronomer's perspective

    International Nuclear Information System (INIS)

    In this review we explore aspects of the field of astrobiology from an astronomical viewpoint. We therefore focus on the origin of life in the context of planetary formation, with additional emphasis on tracing the most abundant volatile elements, C, H, O, and N that are used by life on Earth. We first explore the history of life on our planet and outline the current state of our knowledge regarding the delivery of the C, H, O, N elements to the Earth. We then discuss how astronomers track the gaseous and solid molecular carriers of these volatiles throughout the process of star and planet formation. It is now clear that the early stages of star formation fosters the creation of water and simple organic molecules with enrichments of heavy isotopes. These molecules are found as ice coatings on the solid materials that represent microscopic beginnings of terrestrial worlds. Based on the meteoritic and cometary record, the process of planet formation, and the local environment, lead to additional increases in organic complexity. The astronomical connections towards this stage are only now being directly made. Although the exact details are uncertain, it is likely that the birth process of star and planets likely leads to terrestrial worlds being born with abundant water and organics on the surface

  19. On the Astronomical Records and Babylonian Chronology

    CERN Document Server

    Gurzadyan, V G

    2000-01-01

    We outline the priority of high quality data of astronomical content as our strategy for the analysis of the ancient astronomical records in the search of the absolute chronology of the Near East in II millennium BC. The correspondingly defined set of data for two lunar eclipses of EAE 20 and 21 tablets linked to Ur III period enables us the choice of eclipses of 27 June 1954 BC and 17 March 1912 BC; here the information on the exit position of the darkening of the lunar disk acts as a crucial informator survived in the records. We then discuss why the 56/64 year Venus cycle cannot be traced in the Venus Tablet and therefore cannot serve as an anchor for the search of chronologies. The month length method is discussed as well. In sum the available data support the Ultra-Low Chronology proposed in the book by H.Gasche, J.A.Armstrong, S.W.Cole and V.G.Gurzadyan, "Dating the Fall of Babylon" (1998) and, particularly, leave no astronomical background for the High Chronology. Ultra-Low Chronology is supported also...

  20. Enhanced Management of Personal Astronomical Data with FITSManager

    CERN Document Server

    Cui, Chenzhou; Zhao, Yongheng; Kembhavi, Ajit; He, Boliang; Cao, Zihuang; Li, Jian; Nandrekar, Deoyani

    2011-01-01

    Although the roles of data centers and computing centers are becoming more and more important, and on-line research is becoming the mainstream for astronomy, individual research based on locally hosted data is still very common. With the increase of personal storage capacity, it is easy to find hundreds to thousands of FITS files in the personal computer of an astrophysicist. Because Flexible Image Transport System (FITS) is a professional data format initiated by astronomers and used mainly in the small community, data management toolkits for FITS files are very few. Astronomers need a powerful tool to help them manage their local astronomical data. Although Virtual Observatory (VO) is a network oriented astronomical research environment, its applications and related technologies provide useful solutions to enhance the management and utilization of astronomical data hosted in an astronomer's personal computer. FITSManager is such a tool to provide astronomers an efficient management and utilization of their ...

  1. The Habitable-zone Planet Finder Calibration System

    CERN Document Server

    Halverson, Samuel; Ramsey, Lawrence; Terrien, Ryan; Roy, Arpita; Schwab, Christian; Bender, Chad; Hearty, Fred; Levi, Eric; Osterman, Steve; Ycas, Gabe; Diddams, Scott

    2014-01-01

    We present the design concept of the wavelength calibration system for the Habitable-zone Planet Finder instrument (HPF), a precision radial velocity (RV) spectrograph designed to detect terrestrial-mass planets around M-dwarfs. HPF is a stabilized, fiber-fed, R$\\sim$50,000 spectrograph operating in the near-infrared (NIR) z/Y/J bands from 0.84 to 1.3 microns. For HPF to achieve 1 m s$^{-1}$ or better measurement precision, a unique calibration system, stable to several times better precision, will be needed to accurately remove instrumental effects at an unprecedented level in the NIR. The primary wavelength calibration source is a laser frequency comb (LFC), currently in development at NIST Boulder, discussed separately in these proceedings. The LFC will be supplemented by a stabilized single-mode fiber Fabry-Perot interferometer reference source and Uranium-Neon lamp. The HPF calibration system will combine several other new technologies developed by the Penn State Optical-Infrared instrumentation group to...

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

    CERN Document Server

    Sugai, Hajime; 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; Hsuc, 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; Vilaça, Rodrigo de Paiva; Partos, Eamon J; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J; Riddle, Reed; Santos, Leandro; Santos, Jesulino Bispo dos; 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

    2014-01-01

    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 um to 1.26 um, 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 um to 0.89 um also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts project, while Hyper Suprime-Cam works on the imaging part. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated glass-molded microlens is glued to each fiber tip. 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 componen...

  3. The Rosetta Alice Ultraviolet Spectrograph Investigation: The First UV Spectrograph to Reach a Comet—Results Overview

    Science.gov (United States)

    Stern, S. Alan; Parker, Joel Wm.; A'Hearn, Michael F.; Bertaux, Jean-Loup; Feaga, Lori M.; Feldman, Paul D.; Keeney, Brian A.; Noonan, John; Schindhelm, Eric; Steffl, Andrew; Weaver, Harold A.

    2016-10-01

    Numerous scientific results have been obtained from the exploration of comet 67P/Churyumov-Gerasimenko by the ESA/NASA Rosetta mission. The Alice far/extreme-UV spectrograph aboard Rosetta is one of three US instruments provided by NASA to this mission; it is the first UV spectrograph to reach any comet. We will summarize the main results obtained by the Alice instrument to date, including both surface and coma studies. Notable results we will highlight will include: the discovery of electron impact excitation as the dominant UV emission mechanism near the comet, the detection of molecular oxygen at surprisingly high abundance in the coma, the lack of strong water-ice signatures on the comet's surface during the approach to perihelion, numerous results concerning cometary outbursts, and a large database of systematics relating to atomic and molecular species abundances as the comet approached and then receded from the Sun over a span of two year surrounding the comet's August 2015 perihelion.

  4. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina

    2016-05-02

    This poster presents the development, implementation, and operation of the Broadband Outdoor Radiometer Calibrations (BORCAL) Longwave (LW) system at the Southern Great Plains Radiometric Calibration Facility for the calibration of pyrgeometers that provide traceability to the World Infrared Standard Group.

  5. Science Case and Requirements for the MOSAIC Concept for a Multi-Object Spectrograph for the European Extremely Large Telescope

    CERN Document Server

    Evans, C J; Barbuy, B; Bonifacio, P; Cuby, J -G; Guenther, E; Hammer, F; Jagourel, P; Kaper, L; Morris, S L; Afonso, J; Amram, P; Aussel, H; Basden, A; Bastian, N; Battaglia, G; Biller, B; Bouché, N; Caffau, E; Charlot, S; Clenet, Y; Combes, F; Conselice, C; Contini, T; Dalton, G; Davies, B; Disseau, K; Dunlop, J; Fiore, F; Flores, H; Fusco, T; Gadotti, D; Gallazzi, A; Giallongo, E; Gonçalves, T; Gratadour, D; Hill, V; Huertas-Company, M; Ibata, R; Larsen, S; Fèvre, O Le; Lemasle, B; Maraston, C; Mei, S; Mellier, Y; Östlin, G; Paumard, T; Pello, R; Pentericci, L; Petitjean, P; Roth, M; Rouan, D; Schaerer, D; Telles, E; Trager, S; Welikala, N; Zibetti, S; Ziegler, B

    2014-01-01

    Over the past 18 months we have revisited the science requirements for a multi-object spectrograph (MOS) for the European Extremely Large Telescope (E-ELT). These efforts span the full range of E-ELT science and include input from a broad cross-section of astronomers across the ESO partner countries. In this contribution we summarise the key cases relating to studies of high-redshift galaxies, galaxy evolution, and stellar populations, with a more expansive presentation of a new case relating to detection of exoplanets in stellar clusters. A general requirement is the need for two observational modes to best exploit the large (>40 sq. arcmin) patrol field of the E-ELT. The first mode ('high multiplex') requires integrated-light (or coarsely resolved) optical/near-IR spectroscopy of >100 objects simultaneously. The second ('high definition'), enabled by wide-field adaptive optics, requires spatially-resolved, near-IR of >10 objects/sub-fields. Within the context of the conceptual study for an ELT-MOS called MO...

  6. Cosmic Origins Spectrograph: On-Orbit Performance of Target Acquisitions

    Science.gov (United States)

    Penton, Steven V.

    2010-07-01

    COS is a slit-less spectrograph with a very small aperture (R=1.2500). To achieve the desired wavelength accuracies, HST+COS must center the target to within 0.100 of the center of the aperture for the FUV channel, and 0.0400 for NUV. During SMOV and early Cycle 17 we fine-tuned the COS target acquisition (TA) procedures to exceed this accuracy for all three COS TA modes; NUV imaging, NUV spectroscopic, and FUV spectroscopic. In Cycle 17, we also adjusted the COSto- FGS offsets in the SIAF file. This allows us to recommend skipping the time consuming ACQ/SEARCH in cases where the target coordinates are well known. Here we will compare the on-orbit performance of all COS TA modes in terms of centering accuracy, efficiency, and required signal-to-noise (S/N).

  7. Sound spectrographic analysis of pain cry in preterm infants.

    Science.gov (United States)

    Michelsson, K; Järvenpää, A L; Rinne, A

    1983-07-01

    Sound spectrographic cry analysis was performed on 302 cries of 48 preterm infants born at 30-37 gestational weeks. The cries were recorded during the first week of life and thereafter weekly until the infants were discharged. The control series comprised 54 cries from 27 fullterm healthy infants. The results showed that the cries of the smallest prematures compared with the controls were shorter, more high-pitched, and included bi-phonation and glide more often. The cry characteristics changed with increasing conceptual age and the older the child the more the cry pattern resembled that of the fullterm. The cries of the preterm infants when they had reached 38 conceptual weeks were similar to those of newly born fullterm infants. The results indicate that the gestational age should be taken into consideration in cry analysis. PMID:6884256

  8. Spectrographic determination of traces of boron in steels

    International Nuclear Information System (INIS)

    A spectrographic method has been developed to determine quantitatively boron in steels in the 0.5 to 250 ppm concentration range. The samples are dissolved in acids and transformed into oxides, avoiding boron losses by the addition of mannitol. For the fluoride evolution of boron in the dc arc the following compounds have been considered: CuF2, LiF, NaF, and SrF2. CuF2, at a concentration of 10%, provides the highest line-to-background intensity ratio. An arc current of 5 amperes eliminates the interference from iron spectrum on the most sensitive boron line - B 2497.7 A. Variations in chromium and nickel contents have no effect on the analytical results. (author)

  9. Spectrographic analysis of pain cry in neonates with cleft palate.

    Science.gov (United States)

    Michelsson, K; Sirviö, P; Koivisto, M; Sovijärvi, A; Wasz-Höckert, O

    1975-01-01

    52 phonations of 13 cleft palate neonates were analyzed by sound spectrographic methods. 17 phonetical attributes were included in the study and the first signal after the pain stimulus was analyzed. The cries of the cleft palate infants were compared with the crying of 75 normal babies of the same age. No change in the fundamental frequency, melody type and duration of the cries was seen in association with these anatomical defects. Two of the characteristics studied, vibrato and the 'tonal pit', occurred significantly more often in cries of the cleft palate infants than in cries of the control series. The changes in the qualities seen in association with cleft palate and/or cleft lip do not mimic the abnormalities produced by brain damage.

  10. Telescope baffle performance for Lyman Far Ultraviolet Spectrographic Explorer

    Science.gov (United States)

    Morbey, Christopher; Hutchings, J. B.

    1993-07-01

    The Lyman Far Ultraviolet Spectrographic Explorer telescope is a Wolter type II glancing incidence design with an aperture of 64 cm. Because the spacecraft is required to guide on stars fainter than m(v) = 16, a visible light baffle is necessary to protect the FOV from the stray light that results from out-of-field bright sources. Such a baffle system is described here. Total point-source transmittances are computed for incident beams in the range 0-70 deg. Estimates for background brightness on the detector are made for the contribution from direct sunlight and earthshine. Scattering from the black surfaces of the baffle, the vanes, and diffraction at the structure's edges are taken into consideration.

  11. Monitoring evolved stars for binarity with the HERMES spectrograph

    CERN Document Server

    Gorlova, N; Vos, J; Ostensen, R H; Jorissen, A; Van Eck, S; Ikonnikova, N

    2014-01-01

    Binarity is often invoked to explain peculiarities that can not be explained by the standard theory of stellar evolution. Detecting orbital motion via the Doppler effect is the best method to test binarity when direct imaging is not possible. However, when the orbital period exceeds the duration of a typical observing run, monitoring often becomes problematic. Placing a high-throughput spectrograph on a small semi- robotic telescope allowed us to carry out a radial-velocity survey of various types of peculiar evolved stars. In this review we highlight some findings after the first four years of observations. Thus, we detect eccentric binaries among hot subdwarfs, barium, S stars, and post- AGB stars with disks, which are not predicted by the standard binary interaction theory. In disk objects, in addition, we find signs of the on- going mass transfer to the companion, and an intriguing line splitting, which we attribute to the scattered light of the primary.

  12. Updated Multichannel Infrared Solar Spectrograph at Purple Mountain Observatory

    Institute of Scientific and Technical Information of China (English)

    黎辉; 尤建圻; 吴琴娣; 于兴凤

    2002-01-01

    We describe the newly updated multichannel infrared solar spectrograph at the Purple Mountain Observatory that now uses three Apogee APTp grade i scientific CCDs as its detectors and works at three wavelengths, He I 10830 , Call 8542 and Ha, simultaneously. The spectral resolutions of these lines are 0.04776, 0.05113 and 0.05453 per pixel, respectively. Some observation examples are presented. The observed profiles of the three lines demonstrate that redshift and asymmetry exist in the impulsive phase of the given disc flare and both blueshift and redshift exist in the presented flare spray in the impulsive phase of a limb flare. They also indicate that horizontal expansion exists in addition to the quick radial motion in the flare spray.

  13. The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

    CERN Document Server

    Larkin, James E; Wright, Shelley A; Wincentsen, James E; Anderson, David; Chisholm, Eric M; Dekany, Richard G; Dunn, Jennifer S; Ellerbroek, Brent L; Hayano, Yutaka; Phillips, Andrew C; Simard, Luc; Smith, Roger; Suzuki, Ryuji; Weber, Robert W; Weiss, Jason L; Zhang, Kai

    2016-01-01

    IRIS is a near-infrared (0.84 to 2.4 microns) integral field spectrograph and wide-field imager being developed for first light with the Thirty Meter (TMT). It mounts to the advanced optics (AO) system NFIRAOS and has integrated on-instrument wavefront sensors (OIWFS) to achieve diffraction-limited spatial resolution at wavelengths longer than 1 micron. With moderate spectral resolution (R ~4,000 - 8,000) and large bandpass over a continuous field of view, IRIS will open new opportunities in virtually every area of astrophysical science. It will be able to resolve surface features tens of kilometers across Titan, while also mapping the distant galaxies at the scale of an individual star forming region. This paper summarizes the entire design and capabilities, and includes the results from the nearly completed preliminary design phase.

  14. The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

    CERN Document Server

    Moore, Anna M; Wright, Shelley A; Bauman, Brian; Dunn, Jennifer; Ellerbroek, Brent; Phillips, Andrew C; Simard, Luc; Suzuki, Ryuji; Zhang, Kai; Aliado, Ted; Brims, George; Canfield, John; Chen, Shaojie; Dekany, Richard; Delacroix, Alex; Do, Tuan; Herriot, Glen; Ikenoue, Bungo; Johnson, Chris; Meyer, Elliot; Obuchi, Yoshiyuki; Pazder, John; Reshetov, Vladimir; Riddle, Reed; Saito, Sakae; Smith, Roger; Sohn, Ji Man; Uraguchi, Fumihiro; Usuda, Tomonori; Wang, Eric; Wang, Lianqi; Weiss, Jason; Wooff, Robert

    2014-01-01

    We present an overview of the design of IRIS, an infrared (0.84 - 2.4 micron) integral field spectrograph and imaging camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system (NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter aperture. With a primary spectral resolution of 4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a very large vacuum cryogenic system.

  15. Data Reduction Pipeline for the MMT and Magellan Infrared Spectrograph

    CERN Document Server

    Chilingarian, Igor; Moran, Sean; Brown, Warren; McLeod, Brian; Fabricant, Daniel

    2015-01-01

    We describe the new spectroscopic data reduction pipeline for the multi-object MMT/Magellan Infrared Spectrograph. The pipeline is implemented in idl as a stand-alone package and is publicly available in both stable and development versions. We describe novel algorithms for sky subtraction and correction for telluric absorption. We demonstrate that our sky subtraction technique reaches the Poisson limit set by the photon statistics. Our telluric correction uses a hybrid approach by first computing a correction function from an observed stellar spectrum, and then differentially correcting it using a grid of atmosphere transmission models for the target airmass value. The pipeline provides a sufficient level of performance for real time reduction and thus enables data quality control during observations. We reduce an example dataset to demonstrate the high data reduction quality.

  16. New MWPCs for the Munich Q3D spectrograph

    International Nuclear Information System (INIS)

    A position sensitive detector - for light particles - of about 150 cm length and a resolution of proportional0.5 mm is needed for the Munich Q3D spectrograph. For high resolution this detector must follow the curvature ofthe Q3Dsup(s) focal surface. As a substitute for the MWPC of Glaessel two new detectors, a short one (proportional28 cm) and a long one (2 m) of the same type were constructed. The main features are: wire-spacing 0.5 mm, wire thickness 8 μm, particle detection from each position separately, total energy measurement in a subsequent plastic scintillator and thus ΔE/E particle discrimination. The design of the detectors, the associated electronics and their performance in measurements since spring 1981 (short detector) and spring 1982 (long detector) respectively are reported. (orig.)

  17. Photometric calibrations for 21st century science

    Energy Technology Data Exchange (ETDEWEB)

    Kent, Stephen; /Fermilab; Kaiser, Mary Elizabeth; /Johns Hopkins U.; Deustua, Susana E.; /Baltimore, Space Telescope Sci.; Smith, J.Allyn; /Austin Peay State U.; Adelman, Saul; /Citadel Military Coll.; Allam, Sahar S.; /Fermilab; Baptista, Brian; /Indiana U.; Bohlin, Ralph C.; /Baltimore, Space Telescope Sci.; Clem, James L.; /Louisiana State U.; Conley, Alex; /Colorado U.; Edelstein, Jerry; /UC, Berkeley, Space Sci. Dept. /NOAO, Tucson

    2009-02-01

    The answers to fundamental science questions in astrophysics, ranging from the history of the expansion of the universe to the sizes of nearby stars, hinge on our ability to make precise measurements of diverse astronomical objects. As our knowledge of the underlying physics of objects improves along with advances in detectors and instrumentation, the limits on our capability to extract science from measurements is set, not by our lack of understanding of the nature of these objects, but rather by the most mundane of all issues: the precision with which we can calibrate observations in physical units. In principle, photometric calibration is a solved problem - laboratory reference standards such as blackbody furnaces achieve precisions well in excess of those needed for astrophysics. In practice, however, transferring the calibration from these laboratory standards to astronomical objects of interest is far from trivial - the transfer must reach outside the atmosphere, extend over 4{pi} steradians of sky, cover a wide range of wavelengths, and span an enormous dynamic range in intensity. Virtually all spectrophotometric observations today are calibrated against one or more stellar reference sources, such as Vega, which are themselves tied back to laboratory standards in a variety of ways. This system's accuracy is not uniform. Selected regions of the electromagnetic spectrum are calibrated extremely well, but discontinuities of a few percent still exist, e.g., between the optical and infrared. Independently, model stellar atmospheres are used to calibrate the spectra of selected white dwarf stars, e.g. the HST system, but the ultimate accuracy of this system should be verified against laboratory sources. Our traditional standard star systems, while sufficient until now, need to be improved and extended in order to serve future astrophysics experiments. This white paper calls for a program to improve upon and expand the current networks of

  18. HARMONI : A single-field wide-band integral-field spectrograph for the European ELT

    NARCIS (Netherlands)

    Thatte, Niranjan; Tecza, Mathias; Clarke, Fraser; Davies, Roger L.; Remillieux, Alban; Bacon, Roland; Lunney, David; Arribas, Santiago; Mediavilla, Evencio; Gago, Fernando; Bezawada, Naidu; Ferruit, Pierre; Fragoso, Ana; Freeman, David; Fuentes, Javier; Fusco, Thierry; Gallie, Angus; Garcia, Adolfo; Goodsall, Timothy; Gracia, Felix; Jarno, Aurelien; Kosmalski, Johan; Lynn, James; McLay, Stuart; Montgomery, David; Pecontal, Arlette; Schnetler, Hermine; Smith, Harry; Sosa, Dario; Battaglia, Giuseppina; Bowles, Neil; Colina, Luis; Emsellem, Eric; Garcia-Perez, Ana; Gladysz, Szymon; Hook, Isobel; Irwin, Patrick; Jarvis, Matt; Kennicutt, Robert; Levan, Andrew; Longmore, Andy; Magorrian, John; McCaughrean, Mark; Origlia, Livia; Rebolo, Rafael; Rigopoulou, Dimitra; Ryan, Sean; Swinbank, Mark; Tanvir, Nial; Tolstoy, Eline; Verma, Aprajita

    2010-01-01

    We describe the results of a Phase A study for a single field, wide band, near-infrared integral field spectrograph for the European Extremely Large Telescope (E-ELT). HARMONI, the High Angular Resolution Monolithic Optical & Nearinfrared Integral field spectrograph, provides the E-ELT's core spectr

  19. MEGARA spectrograph for the GTC: mechanical and opto-mechanical design

    OpenAIRE

    Maldonado Medina, Manuel; García Vargas, María Luisa; Gil de Paz, Armando; Sánchez Blanco, Ernesto; Pérez Calpena, Ana; Gallego Maestro, Jesús; Carrasco Licea, Esperanza; Sánchez Moreno, Francisco; Vílchez Medina, José

    2012-01-01

    MEGARA (Multi-Espectrografo en GTC de Alta Resolucion para Astronomia) is the future optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) for the GTC 10.4m telescope. This contribution summarizes the current mechanical design of the spectrograph and the adopted solutions for the mechanisms and the opto-mechanical components.

  20. Wide-band mass measurements with a multi-reflection time-of-flight mass spectrograph

    CERN Document Server

    Schury, P; Wada, M; Wollnik, H

    2013-01-01

    We characterize the mass bandwidth of the a multi-reflection time-of-flight mass spectrograph, showing both the functional and useful mass bandwidth. We then demonstrate the use of a multi-reflection time-of-flight mass spectrograph to perform mass measurements in mass bands much wider than the mass bandwidth.

  1. An efficient low- and moderate-resolution spectrograph for the Hale telescope

    Science.gov (United States)

    Oke, J. B.; Gunn, J. E.

    1982-01-01

    A new low-to-moderate resolution spectrograph has been designed and built for the Cassegrain focus of the Hale 5.08-meter telescope. To maximize efficiency, resolution, and wavelength coverage the light is divided into two spectra regions by a dichroic filter behind the entrance slit, after which there are two completely separate spectrographs. The blue spectrograph operates from 3200 A to 5200 A while the red one goes from 5200 A to 10,000 A. The red detector is an 800 x 800 TI CCD while the blue detector is a 320 x 512 RCA CCD or a Shectrograph image pulse-counting system. A Boksenberg IPCS can also be mounted on the blue camera. The overall efficiency of the Cassegrain telescope, spectrographs, and CCD's combined, ranges from 5 percent to 13 percent between 3600 A and 8200 A. The spectrograph is usable from 3200 A to 10,400 A.

  2. Algorithms for classification of astronomical object spectra

    Science.gov (United States)

    Wasiewicz, P.; Szuppe, J.; Hryniewicz, K.

    2015-09-01

    Obtaining interesting celestial objects from tens of thousands or even millions of recorded optical-ultraviolet spectra depends not only on the data quality but also on the accuracy of spectra decomposition. Additionally rapidly growing data volumes demands higher computing power and/or more efficient algorithms implementations. In this paper we speed up the process of substracting iron transitions and fitting Gaussian functions to emission peaks utilising C++ and OpenCL methods together with the NOSQL database. In this paper we implemented typical astronomical methods of detecting peaks in comparison to our previous hybrid methods implemented with CUDA.

  3. An astronomical survey conducted in Belgium

    CERN Document Server

    Naze, Yael

    2013-01-01

    This article presents the results of the first survey conducted in Belgium about the interest and knowledge in astronomy. Two samples were studied, the public at large (667 questionnaires) and students (2589 questionnaires), but the results are generally similar in both samples. We evaluated people's interest, main information source, and attitudes towards astronomy, as well as their supposed and actual knowledge of the subject. The main conclusion is that, despite a poor self-confidence, people do know the basic astronomical concepts. However, that knowledge is not deeply rooted, as reasoning questions show well-spread misconceptions and/or misunderstandings.

  4. Division XII: Commission 6: Astronomical Telegrams

    Science.gov (United States)

    Samus, N. N.; Yamaoka, H.; Gilmore, A. C.; Aksnes, K.; Green, D. W. E.; Marsden, B. G.; Nakano, S.; Lara, Martin; Pitjeva, Elena V.; Sphar, T.; Ticha, J.; Williams, G.

    2015-08-01

    IAU Commission 6 ``Astronomical Telegrams'' had a single business meeting during the Beijing General Assembly of the IAU. It took place on Friday, August 24, 2012. The meeting was attended by five C6 members (N. N. Samus; D. W. E. Green; S. Nakano; J. Ticha; and H. Yamaoka). Also present was Prof. F. Genova as a representative of the IAU Division B. She told the audience about the current restructuring of IAU Commissions and Divisions and consequences for the future of C6.

  5. Le Verrier magnificent and detestable astronomer

    CERN Document Server

    Lequeux, James

    2013-01-01

    Le Verrier was a superb scientist. His discovery of Neptune in 1846 made him the most famous astronomer of his time. He produced a complete theory of the motions of the planets which served as a basis for planetary ephemeris for a full century. Doing this, he discovered an anomaly in the motion of Mercury which later became the first proof of General Relativity. He also founded European meteorology. However his arrogance and bad temper created many enemies, and he was even fired from his position of Director of the Paris Observatory.

  6. The astronomical revolution Copernicus, Kepler, Borelli

    CERN Document Server

    Koyre, Alexandre

    2013-01-01

    Originally published in English in 1973. This volume traces the development of the revolution which so drastically altered man's view of the universe in the sixteenth and seventeenth centuries. The ""astronomical revolution"" was accomplished in three stages, each linked with the work of one man. With Copernicus, the sun became the centre of the universe. With Kepler, celestial dynamics replaced the kinematics of circles and spheres used by Copernicus. With Borelli the unification of celestial and terrestrial physics was completed by abandonment of the circle in favour the straight line to inf

  7. UNI Astronomical Observatory - OAUNI: First light

    CERN Document Server

    Pereyra, Antonio; Meza, Erick; Cori, William; Ricra, José; Zevallos, Maria Isela

    2015-01-01

    We show the actual status of the project to implement the Astronomical Observatory of the National University of Engineering (OAUNI), including its first light. The OAUNI was installed with success at the site of the Huancayo Observatory on the peruvian central Andes. At this time, we are finishing the commissioning phase which includes the testing of all the instruments: optical tube, robotic mount, CCD camera, filter wheel, remote access system, etc. The first light gathered from a stellar field was very promissory. The next step will be to start the scientific programs and to bring support to the undergraduate courses in observational astronomy at the Faculty of Sciences of UNI.

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

    Science.gov (United States)

    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

  9. The Development of Replicated Optical Integral Field Spectrographs and their Application to the Study of Lyman-alpha Emission at Moderate Redshifts

    Science.gov (United States)

    Chonis, Taylor Steven

    In the upcoming era of extremely large ground-based astronomical telescopes, the design of wide-field spectroscopic survey instrumentation has become increasingly complex due to the linear growth of instrument pupil size with telescope diameter for a constant spectral resolving power. The upcoming Visible Integral field Replicable Unit Spectrograph (VIRUS), a baseline array of 150 copies of a simple integral field spectrograph that will be fed by 3:36 x 104 optical fibers on the upgraded Hobby-Eberly Telescope (HET) at McDonald Observatory, represents one of the first uses of large-scale replication to break the relationship between instrument pupil size and telescope diameter. By dividing the telescope's field of view between a large number of smaller and more manageable instruments, the total information grasp of a traditional monolithic survey spectrograph can be achieved at a fraction of the cost and engineering complexity. To highlight the power of this method, VIRUS will execute the HET Dark Energy Experiment (HETDEX) and survey & 420 degrees2 of sky to an emission line flux limit of ˜ 10-17 erg s-1 cm -2 to detect ˜ 106 Lyman-alpha emitting galaxies (LAEs) as probes of large-scale structure at redshifts of 1:9 design and tests of a novel thermal connector and internal camera croygenic components that link the 150 charge-coupled device detectors to the instrument's liquid nitrogen distribution system. Second, the design, testing, and mass production of the suite of volume phase holographic (VPH) diffraction gratings for VIRUS is presented, which highlights the challenge and success associated with producing of a very large number of highly customized optical elements whose performance is crucial to meeting the efficiency requirements of the spectrograph system. To accommodate VIRUS, the HET is undergoing a substantial wide-field upgrade to increase its field of view to 22' in diameter. The previous HET facility Low Resolution Spectrograph (LRS), which was

  10. Relativistic scaling of astronomical quantities and the system of astronomical units

    Science.gov (United States)

    Klioner, S. A.

    2008-02-01

    Context: For relativistic modeling of high-accuracy astronomical data, several time scales are used: barycentric and geocentric coordinate times (TCB and TCG) and two additional time scales (TDB and TT), which are defined as linear functions of TCB and TCG, respectively. Aims: The paper is devoted to a concise, but still detailed, explanation of the reasons and the implications of the relativistic scalings of astronomical quantities induced by the time scales TDB and TT. Methods: We consequently distinguish between quantities and their numerical values expressed in some units. Results: It is argued that the scaled time scales, the scaled spatial coordinates, and the scaled masses should be considered as distinct quantities that can be expressed themselves in any units and not as numerical values of the same quantities expressed in some different, non-SI units (“TDB units” and “TT units”). Along the same lines, the system of astronomical units is discussed in the relativistic framework. The whole freedom in the definitions of the systems of astronomical units for TCB and TDB is demonstrated. A number of possible ways to freeze the freedom are shown and discussed. It is argued that in the future one should think about converting AU into a defined quantity by fixing its value in SI meters.

  11. Care of astronomical telescopes and accessories a manual for the astronomical observer and amateur telescope maker

    CERN Document Server

    Pepin, M Barlow

    2006-01-01

    This is complete guide for anyone who wants to understand more than just the basics of astronomical telescopes and accessories, and how to maintain them in the peak of condition. The latest on safely adjusting, cleaning, and maintaining your equipment is combined with thoroughly updated methods from the old masters.

  12. European astronomers' successes with the Hubble Space Telescope*

    Science.gov (United States)

    1997-02-01

    American opposite number, John Bahcall, prefers to stress those quasar hosts that look like undisturbed galaxies. But the important thing is that we have wonderfully clear pictures to argue about. Quasar theories were mostly pure speculation before we had Hubble." The history of the elements Astronomers at the Hamburger Sternwarte use the Faint Object Spectrograph to analyse ultraviolet light from distant quasars, which they also examine by visible light from the ground. They trace the origin, through cosmic time, of elements like carbon, silicon and iron, from which planets and living things can be built. On its way to Hubble, the quasar light passes through various intervening galaxies and gas clouds, like the skewer of a kebab. Each object visited absorbs some of the quasar light, depending on the local abundances of the elements. As they detect more and more objects, Dieter Reimers and his colleagues form an impression of galaxies building up their stocks of elements progressively through time, by the alchemy of successive generations of stars. Apart from primordial hydrogen the second lightest element, helium, has also been abundant since the origin of the Universe. The first major discovery after Hubble's last refurbishment came from Peter Jakobsen of ESA's Space Science Department at Noordwijk, who detected ionized helium in the remote Universe, by the light of a very distant quasar, 0302-003. That was in January 1994, and since then Jakobsen has looked for the ionized helium using other quasars. He now suspects that this helium is nearly all gathered in clumps, rather than scattered freely through intergalactic space. If so, it greatly increases the estimates of the total mass of ordinary matter in the Universe. Through a lens to the early Universe Natural lenses scattered through the cosmos reveal distant galaxies, and make an astronomical tool for Richard Ellis of the Institute of Astronomy, Cambridge (UK). The strong gravity of an intervening cluster of galaxies

  13. Application of a damped Locally Optimized Combination of Images method to the spectral characterization of faint companions using an Integral Field Spectrograph

    CERN Document Server

    Pueyo, Laurent; Vasisht, Gautam; Brenner, Douglas; Oppenheimer, Ben R; Zimmerman, Neil; Hinkley, Sasha; Parry, Ian; Beichman, Charles; Hillenbrand, Lynne; Roberts, Lewis C; Dekany, Richard; Shao, Mike; Burruss, Rick; Bouchez, Antonin; Roberts, Jenny; Soummer, Rémi

    2011-01-01

    High-contrast imaging instruments are now being equipped with integral field spectrographs (IFS) to facilitate the detection and characterization of faint substellar companions. Algorithms currently envisioned to handle IFS data, such as the Locally Optimized Combination of Images (LOCI) algorithm, rely upon aggressive point-spread-function (PSF) subtraction, which is ideal for initially identifying companions but results in significantly biased photometry and spectroscopy due to unwanted mixing with residual starlight. This spectro-photometric issue is further complicated by the fact that algorithmic color response is a function of the companion's spectrum, making it difficult to calibrate the effects of the reduction without using iterations involving a series of injected synthetic companions. In this paper, we introduce a new PSF calibration method, which we call "damped LOCI", that seeks to alleviate these concerns. By modifying the cost function that determines the weighting coefficients used to construc...

  14. Sketching the moon an astronomical artist's guide

    CERN Document Server

    Handy, Richard; McCague, Thomas; Rix, Erika; Russell, Sally

    2012-01-01

    Soon after you begin studying the sky through your small telescope or binoculars, you will probably be encouraged by others to make sketches of what you see. Sketching is a time-honored tradition in amateur astronomy and dates back to the earliest times, when telescopes were invented. Even though we have lots of new imaging technologies nowadays, including astrophotography, most observers still use sketching to keep a record of what they see, make them better observers, and in hopes of perhaps contributing something to the body of scientific knowledge about the Moon. Some even sketch because it satisfies their artistic side. The Moon presents some unique challenges to the astronomer-artist, the Moon being so fond of tricks of the light. Sketching the Moon: An Astronomical Artist’s Guide, by five of the best lunar observer-artists working today, will guide you along your way and help you to achieve really high-quality sketches. All the major types of lunar features are covered, with a variety of sketching te...

  15. Powerful Radio Burst Indicates New Astronomical Phenomenon

    Science.gov (United States)

    2007-09-01

    Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say indicates an entirely new type of astronomical phenomenon. Region of Strong Radio Burst Visible-light (negative greyscale) and radio (contours) image of Small Magellanic Cloud and area where burst originated. CREDIT: Lorimer et al., NRAO/AUI/NSF Click on image for high-resolution file ( 114 KB) "This burst appears to have originated from the distant Universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer, Assistant Professor of Physics at West Virginia University (WVU) and the National Radio Astronomy Observatory (NRAO). The research team led by Lorimer consists of Matthew Bailes of Swinburne University in Australia, Maura McLaughlin of WVU and NRAO, David Narkevic of WVU, and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pennsylvania. The astronomers announced their findings in the September 27 issue of the online journal Science Express. The startling discovery came as WVU undergraduate student David Narkevic re-analyzed data from observations of the Small Magellanic Cloud made by the 210-foot Parkes radio telescope in Australia. The data came from a survey of the Magellanic Clouds that included 480 hours of observations. "This survey had sought to discover new pulsars, and the data already had been searched for the type of pulsating signals they produce," Lorimer said. "We re-examined the data, looking for bursts that, unlike the usual ones from pulsars, are not periodic," he added. The survey had covered the Magellanic Clouds, a pair of small galaxies in orbit around our own Milky Way Galaxy. Some 200,000 light-years from Earth, the Magellanic Clouds are prominent features in the Southern sky. Ironically, the new discovery is not part of these galaxies, but rather is much more distant

  16. Digitization of Archives of Astronomical Plates

    Science.gov (United States)

    Omizzolo, Alessandro; Cesare, Barbieri; Blanco, Carlo; Bucciarelli, Beatrice; di Paola, Andrea; Nesci, Roberto

    The photographic plate archives of telescopes around the world contain a veritable treasury of astronomical data. Unfortunately the emulsion is a volatile support and full exploitation of the scientific content is more and more difficult. A large-scale two-year project to digitize the archive of plates of the Italian Astronomical Observatories and of the Specola Vaticana has been started in 2002 with funds from the Ministry of the University and Research following a pilot program funded by the University of Padova in 2001. Identical systems composed by a high quality commercial scanner plus dedicated personal computers and acquisition software (developed initially at DLR Berlin) have been installed in all participating Institutes. Three main goals make up the total project: to provide high quality photometric sequences with the Campo Imperatore telescopes to be used on the scanned plates to perform astrometric measures taking advantage of the large span of time covered by the plates and to distribute the digitized information to all interested researchers via the international Web. This paper presents some of the activities carried out and results obtained so far

  17. Astronomical Surveys, Catalogs, Databases, and Archives

    Science.gov (United States)

    Mickaelian, A. M.

    2016-06-01

    All-sky and large-area astronomical surveys and their cataloged data over the whole range of electromagnetic spectrum are reviewed, from γ-ray to radio, such as Fermi-GLAST and INTEGRAL in γ-ray, ROSAT, XMM and Chandra in X-ray, GALEX in UV, SDSS and several POSS I and II based catalogues (APM, MAPS, USNO, GSC) in optical range, 2MASS in NIR, WISE and AKARI IRC in MIR, IRAS and AKARI FIS in FIR, NVSS and FIRST in radio and many others, as well as most important surveys giving optical images (DSS I and II, SDSS, etc.), proper motions (Tycho, USNO, Gaia), variability (GCVS, NSVS, ASAS, Catalina, Pan-STARRS) and spectroscopic data (FBS, SBS, Case, HQS, HES, SDSS, CALIFA, GAMA). Most important astronomical databases and archives are reviewed as well, including Wide-Field Plate DataBase (WFPDB), ESO, HEASARC, IRSA and MAST archives, CDS SIMBAD, VizieR and Aladin, NED and HyperLEDA extragalactic databases, ADS and astro-ph services. They are powerful sources for many-sided efficient research using Virtual Observatory tools. Using and analysis of Big Data accumulated in astronomy lead to many new discoveries.

  18. Automated object detection for astronomical images

    Science.gov (United States)

    Orellana, Sonny; Zhao, Lei; Boussalis, Helen; Liu, Charles; Rad, Khosrow; Dong, Jane

    2005-10-01

    Sponsored by the National Aeronautical Space Association (NASA), the Synergetic Education and Research in Enabling NASA-centered Academic Development of Engineers and Space Scientists (SERENADES) Laboratory was established at California State University, Los Angeles (CSULA). An important on-going research activity in this lab is to develop an easy-to-use image analysis software with the capability of automated object detection to facilitate astronomical research. This paper presented a fast object detection algorithm based on the characteristics of astronomical images. This algorithm consists of three steps. First, the foreground and background are separated using histogram-based approach. Second, connectivity analysis is conducted to extract individual object. The final step is post processing which refines the detection results. To improve the detection accuracy when some objects are blocked by clouds, top-hat transform is employed to split the sky into cloudy region and non-cloudy region. A multi-level thresholding algorithm is developed to select the optimal threshold for different regions. Experimental results show that our proposed approach can successfully detect the blocked objects by clouds.

  19. Powerful Radio Burst Indicates New Astronomical Phenomenon

    Science.gov (United States)

    2007-09-01

    Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say indicates an entirely new type of astronomical phenomenon. Region of Strong Radio Burst Visible-light (negative greyscale) and radio (contours) image of Small Magellanic Cloud and area where burst originated. CREDIT: Lorimer et al., NRAO/AUI/NSF Click on image for high-resolution file ( 114 KB) "This burst appears to have originated from the distant Universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer, Assistant Professor of Physics at West Virginia University (WVU) and the National Radio Astronomy Observatory (NRAO). The research team led by Lorimer consists of Matthew Bailes of Swinburne University in Australia, Maura McLaughlin of WVU and NRAO, David Narkevic of WVU, and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pennsylvania. The astronomers announced their findings in the September 27 issue of the online journal Science Express. The startling discovery came as WVU undergraduate student David Narkevic re-analyzed data from observations of the Small Magellanic Cloud made by the 210-foot Parkes radio telescope in Australia. The data came from a survey of the Magellanic Clouds that included 480 hours of observations. "This survey had sought to discover new pulsars, and the data already had been searched for the type of pulsating signals they produce," Lorimer said. "We re-examined the data, looking for bursts that, unlike the usual ones from pulsars, are not periodic," he added. The survey had covered the Magellanic Clouds, a pair of small galaxies in orbit around our own Milky Way Galaxy. Some 200,000 light-years from Earth, the Magellanic Clouds are prominent features in the Southern sky. Ironically, the new discovery is not part of these galaxies, but rather is much more distant

  20. Grid-Enabled Interactive Data Language for Astronomical Data Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Grid technologies provide a valuable solution for data intensive scientific applications but are not readily available for astronomical data and Interactive Data...

  1. The First Astronomical Observatory in Cluj-Napoca

    Science.gov (United States)

    Szenkovits, Ferenc

    2008-09-01

    One of the most important cities of Romania is Cluj-Napoca (Kolozsvár, Klausenburg). This is a traditional center of education, with many universities and high schools. From the second half of the 18th century the University of Cluj has its own Astronomical Observatory, serving for didactical activities and scientific researches. The famous astronomer Maximillian Hell was one of those Jesuits who put the base of this Astronomical Observatory. Our purpose is to offer a short history of the beginnings of this Astronomical Observatory.

  2. Gemini GMOS and WHT SAURON integral-field spectrograph observations of the AGN-driven outflow in NGC 1266

    NARCIS (Netherlands)

    Davis, Timothy A.; Krajnovic, Davor; McDermid, Richard M.; Bureau, Martin; Sarzi, Marc; Nyland, Kristina; Alatalo, Katherine; Bayet, Estelle; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Cappellari, Michele; Crocker, Alison; Davies, Roger L.; de Zeeuw, P. T.; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Kuntschner, Harald; Lablanche, Pierre-Yves; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie; Young, Lisa M.

    2012-01-01

    We use the Spectrographic Areal Unit for Research on Optical Nebulae and Gemini Multi-Object Spectrograph integral-field spectrographs to observe the active galactic nucleus (AGN) powered outflow in NGC?1266. This unusual galaxy is relatively nearby (D = 30?Mpc), allowing us to investigate the proce

  3. Forecasting the precipitable water vapour content: validation for astronomical observatories using radiosoundings

    Science.gov (United States)

    Pérez-Jordán, G.; Castro-Almazán, J. A.; Muñoz-Tuñón, C.; Codina, B.; Vernin, J.

    2015-09-01

    The atmospheric precipitable water vapour content (PWV) strongly affects astronomical observations in the infrared (IR). We have validated the Weather Research and Forecasting (WRF) mesoscale numerical weather prediction (NWP) model as an operational forecasting tool for PWV. In the validation, we used atmospheric radiosounding data obtained directly at the Roque de los Muchachos Observatory [ORM: ≈2200 metres above sea level (masl)] during three intensive runs and an aditional verification sample of 1 yr of radiosonde data from World Meteorological Organization (WMO) station 60018 in Güímar (Tenerife, TFE: ≈105 masl). These data sets allowed us to calibrate the model at the observatory site and to validate it under different PWV and atmospheric conditions. The ability of the WRF model in forecasting the PWV at astronomical observatories and the effects of horizontal model grid size on the computed PWV and vertical profiles of humidity are discussed. An excellent agreement between model forecasts and observations was found at both locations, with correlations above 0.9 in all cases. Subtle but significant differences between model horizontal resolutions have been found, the 3 km grid size being the most accurate and the one selected for future work. Absolute calibrations are given for the lowest and finest grid resolutions. The median PWV values obtained were 3.8 and 18.3 mm at ORM and TFE, respectively. WRF forecasts will complement the PWV measured by the GPS monitoring system at the Canarian Observatories.

  4. The Habitable-Zone Planet Finder: A Stabilized Fiber-Fed NIR Spectrograph for the Hobby-Eberly Telescope

    CERN Document Server

    Mahadevan, Suvrath; Bender, Chad; Terrien, Ryan; Wright, Jason T; Halverson, Sam; Hearty, Fred; Nelson, Matt; Burton, Adam; Redman, Stephen; Osterman, Steven; Diddams, Scott; Kasting, James; Endl, Michael; Deshpande, Rohit

    2012-01-01

    We present the scientific motivation and conceptual design for the recently funded Habitable-zone Planet Finder (HPF), a stabilized fiber-fed near-infrared (NIR) spectrograph for the 10 meter class Hobby-Eberly Telescope (HET) that will be capable of discovering low mass planets around M dwarfs. The HPF will cover the NIR Y & J bands to enable precise radial velocities to be obtained on mid M dwarfs, and enable the detection of low mass planets around these stars. The conceptual design is comprised of a cryostat cooled to 200K, a dual fiber-feed with a science and calibration fiber, a gold coated mosaic echelle grating, and a Teledyne Hawaii-2RG (H2RG) NIR detector with a 1.7$\\mu$m cutoff. A uranium-neon hollow-cathode lamp is the baseline wavelength calibration source, and we are actively testing laser frequency combs to enable even higher radial velocity precision. We will present the overall instrument system design and integration with the HET, and discuss major system challenges, key choices, and ong...

  5. The Application of Artificial Neural Networks to Astronomical Classification

    Science.gov (United States)

    Naim, A.

    1995-12-01

    the work of a human expert, usually by showing examples for which the true answer is supplied by the expert. These methods are mostly intended to save time and effort in the less complex stages of the analysis. The unsupervised approach is aimed at learning new things from the data, and is most useful when the data cannot easily be plotted in two or three dimensions. This approach uses only an organising criterion in order to arrange the data, but there is no teacher, nor is there a true answer. The main problem to which I applied ANNs is the morphological classification of galaxies from their digitised images. On the one hand galaxian morphologies appear to be well correlated with the physics of their interiors, while on the other hand they are the most readily available type of extragalactic information to date. Knowing the morphologies of galaxies can help in defining target lists for observations, in the analysis of the morphology-density relation and in calibrating distances by using morphology-specific relations (e.g., the Faber-Jackson relation for ellipticals and the Tully-Fisher relation for spirals). The entire process - data reduction, feature extraction and classification - was automated and, as demonstrated towards the end of this thesis, is readily applicable to very large numbers of galaxies. The most important implication of this work is the generality of the methods used. This is only a demonstration of the powerful tools now available for astronomical data analysis. In coming years researchers will have to make use of such methods in order to solve more and more problems in Astronomy. I would like to acknowledge the financial support I received in the form of an Overseas Research Studentship and the Isaac Newton Studentship.

  6. Planet from another galaxy discovered - Galactic cannibalism brings an exoplanet of extragalactic origin within astronomers' reach

    Science.gov (United States)

    2010-11-01

    An exoplanet orbiting a star that entered our Milky Way from another galaxy has been detected by a European team of astronomers using the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. The Jupiter-like planet is particularly unusual, as it is orbiting a star nearing the end of its life and could be about to be engulfed by it, giving tantalising clues about the fate of our own planetary system in the distant future. Over the last 15 years, astronomers have detected nearly 500 planets orbiting stars in our cosmic neighbourhood, but none outside our Milky Way has been confirmed [1]. Now, however, a planet with a minimum mass 1.25 times that of Jupiter [2] has been discovered orbiting a star of extragalactic origin, even though the star now finds itself within our own galaxy. It is part of the so-called Helmi stream [3] - a group of stars that originally belonged to a dwarf galaxy that was devoured by our galaxy, the Milky Way, in an act of galactic cannibalism about six to nine billion years ago. The results are published today in Science Express. "This discovery is very exciting," says Rainer Klement of the Max-Planck-Institut für Astronomie (MPIA), who was responsible for the selection of the target stars for this study. "For the first time, astronomers have detected a planetary system in a stellar stream of extragalactic origin. Because of the great distances involved, there are no confirmed detections of planets in other galaxies. But this cosmic merger has brought an extragalactic planet within our reach." The star is known as HIP 13044, and it lies about 2000 light-years from Earth in the southern constellation of Fornax (the Furnace). The astronomers detected the planet, called HIP 13044 b, by looking for the tiny telltale wobbles of the star caused by the gravitational tug of an orbiting companion. For these precise observations, the team used the high-resolution spectrograph FEROS [4] attached to the 2.2-metre MPG/ESO telescope [5] at

  7. ISO Results Presented at International Astronomical Union

    Science.gov (United States)

    1997-08-01

    Some of the work being presented is collected in the attached ESA Information Note N 25-97, ISO illuminates our cosmic ancestry. A set of six colour images illustrating various aspects have also been released and are available at http://www.estec.esa.nl/spdwww/iso1808.htm or in hard copy from ESA Public Relations Paris (fax:+33.1.5369.7690). These pictures cover: 1. Distant but powerful infrared galaxies 2. A scan across the milky way 3. Helix nebula: the shroud of a dead star 4. Supernova remnant Cassiopeia A 5. Trifid nebula: a dusty birthplace of stars 6. Precursors of stars and planets The International Astronomical Union provides a forum where astronomers from all over the world can develop astronomy in all its aspects through international co-operation. General Assemblies are held every three years. It is expected that over 1600 astronomers will attend this year's meeting, which is being held in Kyoto, Japan from 18-30 August. Further information on the meeting can be found at: www.tenmon.or.jp/iau97/ . ISO illuminates our cosmic ancestry The European Space Agency's Infrared Space Observatory, ISO, is unmatched in its ability to explore and analyse many of the universal processes that made our existence possible. We are children of the stars. Every atom in our bodies was created in cosmic space and delivered to the Sun's vicinity in time for the Earth's formation, during a ceaseless cycle of birth, death and rebirth among the stars. The most creative places in the sky are cool and dusty, and opaque even to the Hubble Space Telescope. Infrared rays penetrating the dust reveal to ISO hidden objects, and the atoms and molecules of cosmic chemistry. "ISO is reading Nature's recipe book," says Roger Bonnet, ESA's director of science. "As the world's only telescope capable of observing the Universe over a wide range of infrared wavelengths, ISO plays an indispensable part in astronomical discoveries that help to explain how we came to exist." This Information Note

  8. Brightness Variations of Sun-like Stars: The Mystery Deepens - Astronomers facing Socratic "ignorance"

    Science.gov (United States)

    2009-12-01

    An extensive study made with ESO's Very Large Telescope deepens a long-standing mystery in the study of stars similar to the Sun. Unusual year-long variations in the brightness of about one third of all Sun-like stars during the latter stages of their lives still remain unexplained. Over the past few decades, astronomers have offered many possible explanations, but the new, painstaking observations contradict them all and only deepen the mystery. The search for a suitable interpretation is on. "Astronomers are left in the dark, and for once, we do not enjoy it," says Christine Nicholls from Mount Stromlo Observatory, Australia, lead author of a paper reporting the study. "We have obtained the most comprehensive set of observations to date for this class of Sun-like stars, and they clearly show that all the possible explanations for their unusual behaviour just fail." The mystery investigated by the team dates back to the 1930s and affects about a third of Sun-like stars in our Milky Way and other galaxies. All stars with masses similar to our Sun become, towards the end of their lives, red, cool and extremely large, just before retiring as white dwarfs. Also known as red giants, these elderly stars exhibit very strong periodic variations in their luminosity over timescales up to a couple of years. "Such variations are thought to be caused by what we call 'stellar pulsations'," says Nicholls. "Roughly speaking, the giant star swells and shrinks, becoming brighter and dimmer in a regular pattern. However, one third of these stars show an unexplained additional periodic variation, on even longer timescales - up to five years." In order to find out the origin of this secondary feature, the astronomers monitored 58 stars in our galactic neighbour, the Large Magellanic Cloud, over two and a half years. They acquired spectra using the high resolution FLAMES/GIRAFFE spectrograph on ESO's Very Large Telescope and combined them with images from other telescopes [1

  9. The External Calibrator for Hydrogen Observatories

    CERN Document Server

    Jacobs, Daniel C; Bowman, Judd; Neben, Abraham R; Stinnett, Benjamin; Turner, Lauren

    2016-01-01

    Multiple instruments are pursuing constraints on dark energy, observing reionization and opening a window on the dark ages through the detection and characterization of the 21cm hydrogen line across the redshift spectrum, from nearby to z=25. These instruments, including CHIME in the sub-meter and HERA in the meter bands, are wide-field arrays with multiple-degree beams, typically operating in transit mode. Accurate knowledge of their primary beams is critical for separation of bright foregrounds from the desired cosmological signals, but difficult to achieve through astronomical observations alone. Previous beam calibration work has focused on model verification and does not address the need of 21cm experiments for routine beam mapping, to the horizon, of the as-built array. We describe the design and methodology of a drone-mounted calibrator, the External Calibrator for Hydrogen Observatories (ECHO), that aims to address this need. We report on a first set of trials to calibrate low-frequency dipoles and co...

  10. Auroral spectrograph data annals of the international geophysical year, v.25

    CERN Document Server

    Carrigan, Anne; Norman, S J

    1964-01-01

    Annals of the International Geophysical Year, Volume 25: Auroral Spectrograph Data is a five-chapter text that contains tabulations of auroral spectrograph data. The patrol spectrograph built by the Perkin-Elmer Corporation for the Aurora and Airglow Program of the IGY is a high-speed, low-dispersion, automatic instrument designed to photograph spectra of aurora occurring along a given magnetic meridian of the sky. Data from each spectral frame were recorded on an IBM punched card. The data recorded on the cards are printed onto the tabulations in this volume. These tabulations are available

  11. Mathematical model of orbital and ground-based cross-dispersion spectrographs

    Science.gov (United States)

    Yushkin, M. V.; Fatkhullin, T. A.; Panchuk, V. E.

    2016-07-01

    We present the technique and algorithm of numerical modeling of high-resolution spectroscopic equipment. The software is implemented in C++ using nVidia CUDA technology. We report the results of currently developedmodeling of new-generation echelle spectrographs. To validate the algorithms used to construct the mathematical model, we present the results of modeling of NES spectrograph of the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. A comparison of simulated and real images of the spectra acquired with NES spectrograph demonstrates good agreement between the model constructed and experimental data.

  12. EMIR, the GTC nir multi-object imager-spectrograph

    Directory of Open Access Journals (Sweden)

    F. Garzón

    2007-01-01

    Full Text Available EMIR, que esta actualmente cubriendo sus fases de fabricación y AIV, será uno de los primeros instrumentos de uso común en GTC el telescopio de 10m en construcción por GRANTECAN en el Observatorio del Roque de los Muchachos (Canarias, España. EMIR se construye por un consorcio de instituciones españolas y francesas, dirigido por el Instituto de Astrofísica de Canarias (IAC y está concebido para cubrir uno de los objetivos centrales de los telescopios de la clase de 10-m, el cual es obtener un gran número de espectros de fuentes débiles simultáneamente. EMIR está diseñado para operar principalmente como MOS en la banda K, aunque ofrece un amplio rango de modos de observación que incluyen imagen y espectroscopia, tanto de rendija larga como multiobjeto, en el rango espectral de 0.9 a 2.5 um. Está equipado con dos sistema novedosos en astronomía, que constituyen el corazón del instrumento: un robot reconfigurable de multimáscaras, de un lado, y elementos dispersivos formados por combinación de redes de difracción de alta calidad y prismas convencionales. Presentamos el estado actual de desarrollo, las prestaciones previstas y los planes iniciales para su explotación científica. Los desarrollos y fabricación de EMIR están financiados por GRANTECAN y el Plan Nacional de Astronomía y Astrofísica.

  13. MIFS A Mega Integral Field Spectrograph for the VLT

    CERN Document Server

    Bacon, R; Cabrit, S; Combes, F; Davies, R L; Emsellem, E; Ferruit, P; Franx, M; Gilmore, G; Guiderdoni, B; Lefèvre, O; Morris, S; Pécontal, E; Prieto, E; Sharples, R; Van der Werf, P P; De Zeeuw, P T

    2001-01-01

    We describe MIFS, a second generation integral-field spectrograph for the VLT, operating in the visible wavelength range. It combines a 1'x1' field of view with the improved spatial resolution provided by multi-conjugate adaptive optics and covers a large simultaneous spectral range (0.6-1.0 microns). A separate mode exploits the highest spatial resolution provided by adaptive optics. With this unique combination of capabilities, MIFS has a wide domain of application and a large discovery potential. The MIFS low-spatial resolution mode (sampled at 0.2") combined with the initial MCAO capabilities planned for the VLT will provide ultra-deep fields with a limiting magnitude for spectroscopy of R~28. MIFS will improve the present day detection limit of Lyman alpha emitters by a factor of 100, and will detect low-mass star-forming galaxies to z~7. The MIFS high-spatial resolution mode (3"x3" field sampled at 0.01") is optimized for the next step in (MC)AO. It will probe, e.g., the relationship between supermassiv...

  14. Performance of the Space Telescope Imaging Spectrograph after SM4

    Science.gov (United States)

    Proffitt, Charles R.; Alosi, A.; Bohlin, R. C.; Bostroen, K. A.; Cox, C. R.; Diaz, R. I.; Dixon, W. V.; Goudfrooij, P.; Hodge, P.; Kaiser, M. E.; Lallo, M. D.; Lennon, D.; Niemi, S.; Pascucci, I.; Smith, E.; Wolfe, M. A.; York, B.; Zheng. W.; Gull, T. R.; Lindler, D. J.; Woodgate, B. E.

    2010-01-01

    On May 17, 2009, during the fourth EVA of SM4, astronauts Michael Good and Mike Massimino replaced the failed LVPS-2 circuit board on the Space Telescope Imaging Spectrograph (STIS), restoring this HST instrument to operation after a nearly 6 year hiatus. STIS after this 2009 repair operates in much the same way as it did during the 2001-2004 period of operations with the Side-2 electronics. Internal and external alignments of the instrument are similar to what they had been in 2004, and most changes in performance are modest. The STIS CCD detector continued to experience radiation damage during the hiatus in operations, leading to decreased charge transfer efficiency (CTE) and an increased number of hot pixels. The sensitivities for most modes are surprisingly close to what was expected from simple extrapolation of the 2003-2004 trends, although the echelle modes show somewhat more complex behavior. The biggest surprise was that the dark count rate for the NUV MAMA detector after SM4 has been much larger than had been expected; it is currently about 2.5 times bigger than it was in 2004 and is only slowly decreasing. We discuss how these changes will affect science with STIS now and in the future.

  15. Exposure Time Calculator for Immersion Grating Infrared Spectrograph: IGRINS

    CERN Document Server

    Le, Huynh Anh N; Jaffe, Daniel T; Lee, Jae-Joon; Im, Myungshin; Kaplan, Kyle; Seifahrt, Andreas

    2015-01-01

    We present an exposure-time calculator (ETC) for the Immersion Grating Infrared Spectrograph (IGRINS). The signal and noise values are calculated by taking into account the telluric background emission and absorption, the emission and transmission of the telescope and instrument optics, and the dark current and read noise of the infrared detector arrays. For the atmospheric transmission, we apply models based on the amount of precipitable water vapor along the line of sight to the target. The ETC produces the expected signal-to-noise ratio (S/N) for each resolution element, given the exposure-time and number of exposures. In this paper, we compare the simulated continuum S/N for the early-type star HD 124683 and the late-type star GSS 32, and the simulated emission line S/N for the H2 rovibrational transitions from the Iris Nebula NGC 7023 with the observed IGRINS spectra. The simulated S/N from the ETC is overestimate by 10 - 15 % for the sample continuum targets.

  16. An Interface Region Imaging Spectrograph first view on Solar Spicules

    CERN Document Server

    Pereira, T M D; Carlsson, M; Hansteen, V; Tarbell, T D; Lemen, J; Title, A; Boerner, P; Hurlburt, N; Wülser, J P; Martínez-Sykora, J; Kleint, L; Golub, L; McKillop, S; Reeves, K K; Saar, S; Testa, P; Tian, H; Jaeggli, S; Kankelborg, C

    2014-01-01

    Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere remains unknown. Here we give a first glimpse of what quiet Sun spicules look like when observed with NASA's recently launched Interface Region Imaging Spectrograph (IRIS). Using IRIS spectra and filtergrams that sample the chromosphere and transition region we compare the properties and evolution of spicules as observed in a coordinated campaign with Hinode and the Atmospheric Imaging Assembly. Our IRIS observations allow us to follow the thermal evolution of type II spicules and finally confirm that the fading of Ca II H spicules appears to be caused by rapid heating to higher temperatures. The IRIS spicules do not fade but continue evolving, reaching higher and falling back down after 500-800 s. Ca II H type II spicules are thus the initial stages of violent and hotter events that mostly...

  17. A Database of Phase Calibration Sources and their Radio Spectra for the Giant Metrewave Radio Telescope

    CERN Document Server

    Lal, Dharam V; Sherkar, Sachin S

    2016-01-01

    We are pursuing a project to build a database of phase calibration sources suitable for Giant Metrewave Radio Telescope (GMRT). Here we present the first release of 45 low frequency calibration sources at 235 MHz and 610 MHz. These calibration sources are broadly divided into quasars, radio galaxies and unidentified sources. We provide their flux densities, models for calibration sources, (u,v) plots, final deconvolved restored maps and clean-component lists/files for use in the Astronomical Image Processing System (AIPS) and the Common Astronomy Software Applications (CASA). We also assign a quality factor to each of the calibration sources. These data products are made available online through the GMRT observatory website. In addition we find that (i) these 45 low frequency calibration sources are uniformly distributed in the sky and future efforts to increase the size of the database should populate the sky further, (ii) spectra of these calibration sources are about equally divided between straight, curve...

  18. Young astronomer in Denmark 1946 to 1958

    CERN Document Server

    Høg, Erik

    2015-01-01

    This is a personal account of how I became an astronomer. Fascinated by the stars and planets in the dark sky over Lolland, an island 100 km south of Copenhagen, the interest in astronomy was growing. Encouraged by my teachers, I polished mirrors and built telescopes with generous help from the local blacksmith and I observed light curves of variable stars. Studies at the Copenhagen University from 1950 gradually led me deeper into astronomy, especially astrometry (the astronomy of positions), guided by professor Bengt Str\\"omgren and my mentor dr. phil. Peter Naur. I was lucky to take part in the buildup of the new observatory at Brorfelde during the first difficult years and the ideas I gathered there have contributed to the two astrometry satellites Hipparcos and Gaia launched by the European Space Agency (ESA) in respectively 1989 and 2013.

  19. Thirty years of astronomical discovery with UKIRT

    CERN Document Server

    Davies, John; Robson, Ian; The Scientific Achievement of the United Kingdom InfraRed Telescope

    2013-01-01

    These are the proceedings of an international meeting hosted by the Royal Observatory, Edinburgh, to commemorate the 30th anniversary of the dedication of the UKIRT, the United Kingdom InfraRed Telescope. The volume comprises 31 professional level papers. The first part of the book has 10 thorough reviews of the conception, design and build of the telescope, as well as accounts of some its key instruments such as IRCAM (the common-user infrared camera), CGS4 (the fourth Cooled Grating Spectrometer) and the Wide Field Camera. The second part of the book comprises 14 reviews of scientific achievements during its twenty years of visitor mode operations. The final part of the book is a series of 7 reviews of the results from the multiple surveys being done as part of UKIDSS (UKIRT Infrared Deep Sky Survey). The authors are all experts in their respective fields, for example instrument scientists, operations staff and leading astronomers.

  20. Environmental effects on lunar astronomical observatories

    Science.gov (United States)

    Johnson, Stewart W.; Taylor, G. Jeffrey; Wetzel, John P.

    1992-01-01

    The Moon offers a stable platform with excellent seeing conditions for astronomical observations. Some troublesome aspects of the lunar environment will need to be overcome to realize the full potential of the Moon as an observatory site. Mitigation of negative effects of vacuum, thermal radiation, dust, and micrometeorite impact is feasible with careful engineering and operational planning. Shields against impact, dust, and solar radiation need to be developed. Means of restoring degraded surfaces are probably essential for optical and thermal control surfaces deployed in long-lifetime lunar facilities. Precursor missions should be planned to validate and enhance the understanding of the lunar environment (e.g., dust behavior without and with human presence) and to determine environmental effects on surfaces and components. Precursor missions should generate data useful in establishing keepout zones around observatory facilities where rocket launches and landings, mining, and vehicular traffic could be detrimental to observatory operation.

  1. Library & Information Services as Astronomer's Wishlist

    CERN Document Server

    Andernach, H

    1998-01-01

    I review some of the past and current methods for retrieval of literature and other published information, excluding commercial services. Much of this is a personal view and based on experience made at various institutions, some of them neither with an adequately complete astronomy library, nor with a professional astronomy librarian. Rather than describing current retrieval methods, a few of their weaknesses are identified which merit future improval. Despite the availability of powerful electronic tools, we need to improve efforts in safeguarding published numerical and textual information in a format readily usable by astronomers. Comments are made on a user-friendly arrangement of a library, and on useful tasks for librarians with available time.

  2. Learning Vector Quantization for Classifying Astronomical Objects

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The sizes of astronomical surveys in different wavebands are increas-ing rapidly. Therefore, automatic classification of objects is becoming ever moreimportant. We explore the performance of learning vector quantization (LVQ) inclassifying multi-wavelength data. Our analysis concentrates on separating activesources from non-active ones. Different classes of X-ray emitters populate distinctregions of a multidimensional parameter space. In order to explore the distributionof various objects in a multidimensional parameter space, we positionally cross-correlate the data of quasars, BL Lacs, active galaxies, stars and normal galaxiesin the optical, X-ray and infrared bands. We then apply LVQ to classify them withthe obtained data. Our results show that LVQ is an effective method for separatingAGNs from stars and normal galaxies with multi-wavelength data.

  3. Bonaparte and the astronomers of Brera Observatory

    CERN Document Server

    Antonello, E

    2014-01-01

    In Northern Italy, between 1796 and 1814, Napoleon Bonaparte formed a Republic, and then a Kingdom, controlled by France. Milan was the capital of the State, and the Brera Palace was the main cultural centre, as regards both the arts and the sciences. Bonaparte probably intended to strengthen this characteristic of Brera, aiming at increasing its Italian and European relevance. We will discuss in detail in which way he interacted with the astronomers of Brera Observatory, and in particular with Barnaba Oriani, that was considered the local main representative of the 'republique des lettres', that is, the world of literature, arts and sciences. We propose a possible reconstruction of the effects of those complicated historical events on the Italian astronomy and on its relations with the European one.

  4. Die Gerling Sternwarte (Gerling Astronomical Observatory)

    CERN Document Server

    Schrimpf, Andreas

    2015-01-01

    Christian Ludwig Gerling's 1817 appointment as Professor for Mathematics, Physics and Astronomy resulted in the foundation of the Mathematical and Physical Institute of the Philipps University. In 1838, Gerling moved onto new premises in the main building of the former D\\"ornberger Hof in Renthof Street where the Philipps University's astronomical observatory was installed in the upper part of the old tower in 1841. The most important device at that time was a transit instrument which served to measure the transit times of stars in the meridian. Precise alignment required the use of a meridian stone, an artificial point of reference exactly north of and at about four kilometers' distance from the observatory. The scientists observed planets and their moons, the asteroids that were only discovered at the beginning of the 19th century, and some fainter stars in order to improve stellar charts. The Gerling Observatory is the first place in Hesse, where positions of asteroids were read.

  5. Astronomical research at the Hopkins PHOENIX Observatory

    Science.gov (United States)

    Hopkins, J. L.

    1985-09-01

    After trying astrophotography and radio astronomy it was decided that the best way to do meaningful astronomical research at a small private observatory was by doing photoelectric photometry. Having the observatory located in the back yard of a private residence affors the luxury of observing any time the sky conditions permit. Also modest equipment is all that is needed to do accurate UBV photometry of stars 8th magnitude and brighter. Since beginning in 1980 the Hopkins Phoenix Observatory has published papers on several RS CVn star systems, 31 Cygni, 22 Vul, 18 Tau Per, and has followed the 1982-1984 eclipse of Epsilon Aurigae from its start to the present with over 1000 UBV measurements. In addition the Hopkins Phoenix Observatory has developed several pieces of photometry equipment including the HPO PEPH-101 photometer head and photon counting electronics.

  6. AstroVis: Visualizing astronomical data cubes

    Science.gov (United States)

    Finniss, Stephen; Tyler, Robin; Questiaux, Jacques

    2016-08-01

    AstroVis enables rapid visualization of large data files on platforms supporting the OpenGL rendering library. Radio astronomical observations are typically three dimensional and stored as data cubes. AstroVis implements a scalable approach to accessing these files using three components: a File Access Component (FAC) that reduces the impact of reading time, which speeds up access to the data; the Image Processing Component (IPC), which breaks up the data cube into smaller pieces that can be processed locally and gives a representation of the whole file; and Data Visualization, which implements an approach of Overview + Detail to reduces the dimensions of the data being worked with and the amount of memory required to store it. The result is a 3D display paired with a 2D detail display that contains a small subsection of the original file in full resolution without reducing the data in any way.

  7. Simon Newcomb: America's Unofficial Astronomer Royal

    Science.gov (United States)

    Graham, John

    2007-10-01

    Bill Carter and Merri Sue Carter Mantazas; xiii + 213 pp.; ISBN 1-59113-803-5 2006; $26.95 This book introduced me to a commanding figure in American science from the late nineteenth century: Simon Newcomb. Newcomb has been called the nineteenth-century equivalent of Carl Sagan and Albert Einstein. He rose from humble beginnings to be the preeminent American astronomer of his generation. He made basic, far-reaching, and enduring contributions to positional astronomy and planetary dynamics. On the more practical side, he determined a remarkably accurate value for the velocity of light, one within 0.01% of the value accepted today. His work provided an experimental grounding for the special and general theories of relativity to be formulated by Einstein in the coming twentieth century.

  8. Are Supernovae Recorded in Indigenous Astronomical Traditions?

    CERN Document Server

    Hamacher, Duane W

    2014-01-01

    Novae and supernovae are rare astronomical events that would have had an influence on the sky-watching peoples who witnessed them. Although several bright novae/supernovae have been visible during recorded human history, there are many proposed but no confirmed accounts of supernovae in oral traditions or material culture. Criteria are established for confirming novae/supernovae in oral and material culture, and claims from around the world are discussed to determine if they meet these criteria. Australian Aboriginal traditions are explored for possible descriptions of novae/supernovae. Although representations of supernovae may exist in Indigenous traditions, and an account of a nova in Aboriginal traditions has been confirmed, there are currently no confirmed accounts of supernovae in Indigenous oral or material traditions.

  9. VOStat: A Statistical Web Service for Astronomers

    CERN Document Server

    Chakraborty, Arnab; Babu, G Jogesh

    2013-01-01

    VOStat is a Web service providing interactive statistical analysis of astronomical tabular datasets. It is integrated into the suite of analysis and visualization tools associated with the international Virtual Observatory (VO) through the SAMP communication system. A user supplies VOStat with a dataset extracted from the VO, or otherwise acquired, and chooses among $\\sim 60$ statistical functions. These include data transformations, plots and summaries, density estimation, one- and two-sample hypothesis tests, global and local regressions, multivariate analysis and clustering, spatial analysis, directional statistics, survival analysis (for censored data like upper limits), and time series analysis. The statistical operations are performed using the public domain {\\bf R} statistical software environment, including a small fraction of its $>4000$ {\\bf CRAN} add-on packages. The purpose of VOStat is to facilitate a wider range of statistical analyses than are commonly used in astronomy, and to promote use of m...

  10. Using the Galileoscope in astronomical observations

    CERN Document Server

    Oliveira, V A

    2015-01-01

    This project aims to attract school students and teachers from the state education system from Ca\\c{c}apava do Sul - RS to Sciences and specially to Astronomy. We made astronomical observations using a Galileoscope choosing the Moon as a primary target. We also observed others objects that present high brightness in the night sky. The selection of targets, and their identification during the observations were carried out by a free software of planetary simulation, Stellarium. The results were in qualitative form and they show the great interest demonstrated by those participating in the project. Furthermore, this project helped to improve the understanding of the physical proprieties of the night sky objects (e.g. color). Finally, the project has showed that using a simple equipment and of relatively low cost it is possible to bring more people, specially the young students, to the Science World and to Astronomy.

  11. Multinational History of Strasbourg Astronomical Observatory

    CERN Document Server

    Heck, André

    2005-01-01

    Strasbourg Astronomical Observatory is quite an interesting place for historians: several changes of nationality between France and Germany, high-profile scientists having been based there, big projects born or installed in its walls, and so on. Most of the documents circulating on the history of the Observatory and on related matters have however been so far poorly referenced, if at all. This made necessary the compilation of a volume such as this one, offering fully-documented historical facts and references on the first decades of the Observatory history, authored by both French and German specialists. The experts contributing to this book have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy nor in the details of European history. After an introductory chapter by the Editor, contributions by Wolfschmidt and by Duerbeck respectively deal extensively with the German periods and review people and instrumentation, while another paper by Duerbeck is more...

  12. An Astronomer's View of Climate Change

    Science.gov (United States)

    Morton, Donald C.

    2014-01-01

    There are several astronomical effects that could be important for understanding climate changes such as the ice ages, the Medieval Maximum, the Little Ice Age, the 20th century temperature rise and the small decrease during the past 15 years. These effects include variations in the sun's luminosity, periodic changes in the earth's orbital parameters, the sun's orbit around our galaxy, the solar wind, the variability of solar activity and the anticorrelation of the galactic cosmic ray flux with that activity. With the publication of the Fifth Assessment Report to the Intergoverment Panel on Climate Change, it is useful to review these effects and the extent to which that report and previoius ones have recognized them. This paper also discusses recent trends in solar activity and global temperatures and compares the latter with the predictions of climate models.

  13. Integral Programme of Basic Astronomic Literacy Development

    Science.gov (United States)

    Tignanelli, H.

    2009-05-01

    We discuss the development and optimization of an ongoing educational project involving the whole population of the province of San Luis, Argentina. The core of the project includes activities and resources that capture formal curricular aspects directed towards all levels of teaching. The educational activities related to this project have been benefited by the acquisition of two planetariums made in Argentina, a MEADE 16'' telescope to be operated by remote control from any school-room in San Luis, and a naked-eye observatory with more than 30 pre-telescopic instruments, and other didactic tools specially designed for the teaching of Astronomy. Furthermore, an Internet site to upload all the astronomical activities suggested that has been developed along with a number of didactic and general-interest publications.

  14. Trinocular Calibration Method Based on Binocular Calibration

    Directory of Open Access Journals (Sweden)

    CAO Dan-Dan

    2012-10-01

    Full Text Available In order to solve the self-occlusion problem in plane-based multi-camera calibration system and expand the measurement range, a tri-camera vision system based on binocular calibration is proposed. The three cameras are grouped into two pairs, while the public camera is taken as the reference to build the global coordinate. By calibration of the measured absolute distance and the true absolute distance, global calibration is realized. The MRE (mean relative error of the global calibration of the two camera pairs in the experiments can be as low as 0.277% and 0.328% respectively. Experiment results show that this method is feasible, simple and effective, and has high precision.

  15. Polarization Aberrations in Astronomical Telescopes: The Point Spread Function

    Science.gov (United States)

    Breckinridge, James B.; Lam, Wai Sze T.; Chipman, Russell A.

    2015-05-01

    Detailed knowledge of the image of the point spread function (PSF) is necessary to optimize astronomical coronagraph masks and to understand potential sources of errors in astrometric measurements. The PSF for astronomical telescopes and instruments depends not only on geometric aberrations and scalar wave diffraction but also on those wavefront errors introduced by the physical optics and the polarization properties of reflecting and transmitting surfaces within the optical system. These vector wave aberrations, called polarization aberrations, result from two sources: (1) the mirror coatings necessary to make the highly reflecting mirror surfaces, and (2) the optical prescription with its inevitable non-normal incidence of rays on reflecting surfaces. The purpose of this article is to characterize the importance of polarization aberrations, to describe the analytical tools to calculate the PSF image, and to provide the background to understand how astronomical image data may be affected. To show the order of magnitude of the effects of polarization aberrations on astronomical images, a generic astronomical telescope configuration is analyzed here by modeling a fast Cassegrain telescope followed by a single 90° deviation fold mirror. All mirrors in this example use bare aluminum reflective coatings and the illumination wavelength is 800 nm. Our findings for this example telescope are: (1) The image plane irradiance distribution is the linear superposition of four PSF images: one for each of the two orthogonal polarizations and one for each of two cross-coupled polarization terms. (2) The PSF image is brighter by 9% for one polarization component compared to its orthogonal state. (3) The PSF images for two orthogonal linearly polarization components are shifted with respect to each other, causing the PSF image for unpolarized point sources to become slightly elongated (elliptical) with a centroid separation of about 0.6 mas. This is important for both astrometry

  16. Astronomers Gain Clues About Fundamental Physics

    Science.gov (United States)

    2005-12-01

    An international team of astronomers has looked at something very big -- a distant galaxy -- to study the behavior of things very small -- atoms and molecules -- to gain vital clues about the fundamental nature of our entire Universe. The team used the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) to test whether the laws of nature have changed over vast spans of cosmic time. The Green Bank Telescope The Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF (Click on image for GBT gallery) "The fundamental constants of physics are expected to remain fixed across space and time; that's why they're called constants! Now, however, new theoretical models for the basic structure of matter indicate that they may change. We're testing these predictions." said Nissim Kanekar, an astronomer at the National Radio Astronomy Observatory (NRAO), in Socorro, New Mexico. So far, the scientists' measurements show no change in the constants. "We've put the most stringent limits yet on some changes in these constants, but that's not the end of the story," said Christopher Carilli, another NRAO astronomer. "This is the exciting frontier where astronomy meets particle physics," Carilli explained. The research can help answer fundamental questions about whether the basic components of matter are tiny particles or tiny vibrating strings, how many dimensions the Universe has, and the nature of "dark energy." The astronomers were looking for changes in two quantities: the ratio of the masses of the electron and the proton, and a number physicists call the fine structure constant, a combination of the electron charge, the speed of light and the Planck constant. These values, considered fundamental physical constants, once were "taken as time independent, with values given once and forever" said German particle physicist Christof Wetterich. However, Wetterich explained, "the viewpoint of modern particle theory has changed in recent years," with ideas such as

  17. Old Star's "Rebirth" Gives Astronomers Surprises

    Science.gov (United States)

    2005-04-01

    Astronomers using the National Science Foundation's Very Large Array (VLA) radio telescope are taking advantage of a once-in-a-lifetime opportunity to watch an old star suddenly stir back into new activity after coming to the end of its normal life. Their surprising results have forced them to change their ideas of how such an old, white dwarf star can re-ignite its nuclear furnace for one final blast of energy. Sakurai's Object Radio/Optical Images of Sakurai's Object: Color image shows nebula ejected thousands of years ago. Contours indicate radio emission. Inset is Hubble Space Telescope image, with contours indicating radio emission; this inset shows just the central part of the region. CREDIT: Hajduk et al., NRAO/AUI/NSF, ESO, StSci, NASA Computer simulations had predicted a series of events that would follow such a re-ignition of fusion reactions, but the star didn't follow the script -- events moved 100 times more quickly than the simulations predicted. "We've now produced a new theoretical model of how this process works, and the VLA observations have provided the first evidence supporting our new model," said Albert Zijlstra, of the University of Manchester in the United Kingdom. Zijlstra and his colleagues presented their findings in the April 8 issue of the journal Science. The astronomers studied a star known as V4334 Sgr, in the constellation Sagittarius. It is better known as "Sakurai's Object," after Japanese amateur astronomer Yukio Sakurai, who discovered it on February 20, 1996, when it suddenly burst into new brightness. At first, astronomers thought the outburst was a common nova explosion, but further study showed that Sakurai's Object was anything but common. The star is an old white dwarf that had run out of hydrogen fuel for nuclear fusion reactions in its core. Astronomers believe that some such stars can undergo a final burst of fusion in a shell of helium that surrounds a core of heavier nuclei such as carbon and oxygen. However, the

  18. Daytime School Guided Visits to an Astronomical Observatory in Brazil

    Science.gov (United States)

    Colombo, Pedro Donizete, Jr.; Silva, Cibelle Celestino; Aroca, Silvia Calbo

    2010-01-01

    This article analyzes the activity "Daytime School Guided Visits" at an astronomical observatory in Brazil with pupils from primary school. The adopted research methodology relied on questionnaire applications and semistructured interviews. The objectives were to identify the influences of the visits on learning of astronomical concepts and on…

  19. Using Modern Technologies to Capture and Share Indigenous Astronomical Knowledge

    OpenAIRE

    Nakata, N. M.; Hamacher, D. W.; Warren, J.; Byrne, A; Pagnucco, M.; Harley, R.; Venugopal, S.; Thorpe, K.; Neville, R.; Bolt, R.

    2014-01-01

    Indigenous Knowledge is important for Indigenous communities across the globe and for the advancement of our general scientific knowledge. In particular, Indigenous astronomical knowledge integrates many aspects of Indigenous Knowledge, including seasonal calendars, navigation, food economics, law, ceremony, and social structure. We aim to develop innovative ways of capturing, managing, and disseminating Indigenous astronomical knowledge for Indigenous communities and the general public for t...

  20. The lamps of Atlantis: an astronomical detective story

    Science.gov (United States)

    Roy, Archie E.

    1986-11-01

    The origin of the stellar constellations familiar to western astronomers from ancient times is discussed using astronomical, literary, and archaeological evidence. The precession of the equinoxes, the zone of avoidance and the orientation of the constellations, and early Greek and Minoan astronomy are considered.

  1. The challengers of an astronomer being a journalist

    Science.gov (United States)

    Podorvanyuk, N.

    2015-03-01

    As the weakness of russian astronomers in observational astronomy became chronic Russia should enter European Southern Observatory. But the Russian government is still not providing any financing of the entrance of Russia to ESO. The author states this situation as an example of his experience of work as an astronomer and as a journalist at the same time.

  2. Software Package for Preparing and Processing of an Astronomical Observation

    Science.gov (United States)

    Vaduvescu, Ovidiu; Birlan, Mirel

    This paper presents an astronomical software package which draws celestial charts. It was conceived taking into account the technical possibilities available for the Romanian astronomers and the actual trend of the observational astronomy. The software package, now to its third version, comes to decrease the time to prepare an observation and to perform accurate charts for searching and identification.

  3. Astronomical Books and Charts in the Book of Bibliographie Coreenne

    Science.gov (United States)

    Lee, Ki-Won; Yang, Hong-Jin; Park, Myeong-Gu

    2008-06-01

    We investigate astronomical materials listed in the book of Bibliographie Coréenne written by Maurice Courant. He classified ancient Korean books into nine Divisions (?) and thirty six Classes (?), and published them as three volumes (ranging from 1894 to 1896) and one supplement (in 1901). In total, 3,821 books including astronomical ones are listed together with information on physical size, possessional place, bibliographical note, and so forth. Although this book is an essential one in the field of Korea bibliography and contains many astronomical materials such as Cheon-Mun-Ryu-Cho ????, Si-Heon-Seo ??????, and Cheon-Sang-Yeol-Cha-Bun-Ya-Ji-Do ????????, it has not been well known to the public nor to astronomical society. Of 3,821 catalogues, we found that about 50 Items (?) are related to astronomy or astrology, and verified that most ! of them are located in the Kyujanggak Royal Library ???. We also found an unknown astronomical chart, Hon-Cheon-Chong-Seong-Yeol-Cha-Bun-Ya-Ji-Do ??????????. Because those astronomical materials are not well known to international astronomical community and there have been few studies on the materials in Korea, we here introduce and review them, particularly with the astronomical viewpoint.

  4. The Virtual Astronomical Observatory: Re-engineering Access to Astronomical Data

    CERN Document Server

    Hanisch, R J; Lazio, T J W; Bunn, S Emery; Evans, J; McGlynn, T A; Plante, R

    2015-01-01

    The U.S. Virtual Astronomical Observatory was a software infrastructure and development project designed both to begin the establishment of an operational Virtual Observatory (VO) and to provide the U.S. coordination with the international VO effort. The concept of the VO is to provide the means by which an astronomer is able to discover, access, and process data seamlessly, regardless of its physical location. This paper describes the origins of the VAO, including the predecessor efforts within the U.S. National Virtual Observatory, and summarizes its main accomplishments. These accomplishments include the development of both scripting toolkits that allow scientists to incorporate VO data directly into their reduction and analysis environments and high-level science applications for data discovery, integration, analysis, and catalog cross-comparison. Working with the international community, and based on the experience from the software development, the VAO was a major contributor to international standards ...

  5. The Double Didactic Astronomical Quadrant for the XIII International Astronomical Olympiad

    OpenAIRE

    Maris, Michele; Corte, Claudio; Boehm, Conrad; Iafrate, Giulia; Ramella, Massimo

    2010-01-01

    Here we present the development of a simplified version of double astronomical quadrant, designed for educational aims and realized on the occasion of the observational round of the XIII International Astronomy Olympiad, held in Trieste (Italy) October 13-21, 2008. (Italia: In questo contributo illustriamo il progetto di una versione semplificata di doppio quadrante astronomico, progettato per fini didattici e realizzato in occasione dello svolgimento della gara osservativa delle XIII Olimpia...

  6. Flexible, High Performance Microlens Array Technologies for Integral Field Spectrographs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For the purposes of advancing integral field spectrograph (IFS) microlens capabilities, a new class of high-quality optics-grade nanostructured organic-inorganic...

  7. Visible camera cryostat design and performance for the SuMIRe Prime Focus Spectrograph (PFS)

    CERN Document Server

    Smee, Stephen A; Golebiowski, Mirek; Hope, Stephen C; Madec, Fabrice; Gabriel, Jean-Francois; Loomis, Craig; Fur, Arnaud Le; Dohlen, Kjetil; Mignant, David Le; Barkhouser, Robert; Carr, Michael; Hart, Murdock; Tamura, Naoyuki; Shimono, Atsushi; Takato, Naruhisa

    2016-01-01

    We describe the design and performance of the SuMIRe Prime Focus Spectrograph (PFS) visible camera cryostats. SuMIRe PFS is a massively multi-plexed ground-based spectrograph consisting of four identical spectrograph modules, each receiving roughly 600 fibers from a 2394 fiber robotic positioner at the prime focus. Each spectrograph module has three channels covering wavelength ranges 380~nm -- 640~nm, 640~nm -- 955~nm, and 955~nm -- 1.26~um, with the dispersed light being imaged in each channel by a f/1.07 vacuum Schmidt camera. The cameras are very large, having a clear aperture of 300~mm at the entrance window, and a mass of $\\sim$280~kg. In this paper we describe the design of the visible camera cryostats and discuss various aspects of cryostat performance.

  8. ORNL calibrations facility

    International Nuclear Information System (INIS)

    The ORNL Calibrations Facility is operated by the Instrumentation Group of the Industrial Safety and Applied Health Physics Division. Its primary purpose is to maintain radiation calibration standards for calibration of ORNL health physics instruments and personnel dosimeters. This report includes a discussion of the radioactive sources and ancillary equipment in use and a step-by-step procedure for calibration of those survey instruments and personnel dosimeters in routine use at ORNL

  9. Spectrograph complex for laser plasma X-ray radiation research in ISKRA-4, ISKRA-5 experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bessarab, A.V.; Bel`kov, S.A.; Zhidkov, N.V.; Tokarev, V.A. [VNIIEF Russian Federal Nuclear Center, Novgorod (Russian Federation)

    1994-12-31

    A spectrograph complex, developed for the ISKRA-4 and ISKRA-5 facilities, is described. The complex was developed to study continuous and line spectra in the 0.06-3 keV range. It comprises diffraction-grating, multilayer-mirror, and grazing-incidence crystal spectrographs. Recorded laser plasma X-ray spectra are compared with the ones predicted by the gas-dynamical theory. 9 refs., 2 figs.

  10. A fully automated data reduction pipeline for the FRODOSpec integral field spectrograph

    CERN Document Server

    Barnsley, R M; Steele, I A

    2011-01-01

    A fully autonomous data reduction pipeline has been developed for FRODOSpec, an optical fibre-fed integral field spectrograph currently in use at the Liverpool Telescope. This paper details the process required for the reduction of data taken using an integral field spectrograph and presents an overview of the computational methods implemented to create the pipeline. Analysis of errors and possible future enhancements are also discussed.

  11. Spiral reader calibration

    International Nuclear Information System (INIS)

    The method to calibrate the spiral reader (SR) is presented. A brief description of the main procedures of the calibration program SCALP, adapted for the IHEP equipment and purposes, is described. The precision characteristics of the IHEP SR have been analysed on the results, presented in the form of diagrams. There is a calibration manual for the user

  12. Astronomers Discover Fastest-Spinning Pulsar

    Science.gov (United States)

    2006-01-01

    Astronomers using the National Science Foundation's Robert C. Byrd Green Bank Telescope have discovered the fastest-spinning neutron star ever found, a 20-mile-diameter superdense pulsar whirling faster than the blades of a kitchen blender. Their work yields important new information about the nature of one of the most exotic forms of matter known in the Universe. Pulsar Graphic Pulsars Are Spinning Neutron Stars CREDIT: Bill Saxton, NRAO/AUI/NSF (Click on image for larger version) "We believe that the matter in neutron stars is denser than an atomic nucleus, but it is unclear by how much. Our observations of such a rapidly rotating star set a hard upper limit on its size, and hence on how dense the star can be.," said Jason Hessels, a graduate student at McGill University in Montreal. Hessels and his colleagues presented their findings to the American Astronomical Society's meeting in Washington, DC. Pulsars are spinning neutron stars that sling "lighthouse beams" of radio waves or light around as they spin. A neutron star is what is left after a massive star explodes at the end of its "normal" life. With no nuclear fuel left to produce energy to offset the stellar remnant's weight, its material is compressed to extreme densities. The pressure squeezes together most of its protons and electrons to form neutrons; hence, the name "neutron star." "Neutron stars are incredible laboratories for learning about the physics of the fundamental particles of nature, and this pulsar has given us an important new limit," explained Scott Ransom, an astronomer at the National Radio Astronomy Observatory and one of Hessels' collaborators on this work. The scientists discovered the pulsar, named PSR J1748-2446ad, in a globular cluster of stars called Terzan 5, located some 28,000 light-years from Earth in the constellation Sagittarius. The newly-discovered pulsar is spinning 716 times per second, or at 716 Hertz (Hz), readily beating the previous record of 642 Hz from a pulsar

  13. AN INTERFACE REGION IMAGING SPECTROGRAPH FIRST VIEW ON SOLAR SPICULES

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, T. M. D.; De Pontieu, B.; Carlsson, M.; Hansteen, V. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Tarbell, T. D.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.; Wülser, J. P.; Martínez-Sykora, J.; Kleint, L. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Org. A021S, Bldg. 252, Palo Alto, CA 94304 (United States); Golub, L.; McKillop, S.; Reeves, K. K.; Saar, S.; Testa, P.; Tian, H. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jaeggli, S.; Kankelborg, C., E-mail: tiago.pereira@astro.uio.no [Department of Physics, Montana State University, P.O. Box 173840, Bozeman, MT 59717 (United States)

    2014-09-01

    Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere remains unknown. Here we give a first glimpse of what quiet-Sun spicules look like when observed with NASA's recently launched Interface Region Imaging Spectrograph (IRIS). Using IRIS spectra and filtergrams that sample the chromosphere and transition region, we compare the properties and evolution of spicules as observed in a coordinated campaign with Hinode and the Atmospheric Imaging Assembly. Our IRIS observations allow us to follow the thermal evolution of type II spicules and finally confirm that the fading of Ca II H spicules appears to be caused by rapid heating to higher temperatures. The IRIS spicules do not fade but continue evolving, reaching higher and falling back down after 500-800 s. Ca II H type II spicules are thus the initial stages of violent and hotter events that mostly remain invisible in Ca II H filtergrams. These events have very different properties from type I spicules, which show lower velocities and no fading from chromospheric passbands. The IRIS spectra of spicules show the same signature as their proposed disk counterparts, reinforcing earlier work. Spectroheliograms from spectral rasters also confirm that quiet-Sun spicules originate in bushes from the magnetic network. Our results suggest that type II spicules are indeed the site of vigorous heating (to at least transition region temperatures) along extensive parts of the upward moving spicular plasma.

  14. Compact high-resolution spectrographs for large and extremely large telescopes: using the diffraction limit

    Science.gov (United States)

    Robertson, J. Gordon; Bland-Hawthorn, Joss

    2012-09-01

    As telescopes get larger, the size of a seeing-limited spectrograph for a given resolving power becomes larger also, and for ELTs the size will be so great that high resolution instruments of simple design will be infeasible. Solutions include adaptive optics (but not providing full correction for short wavelengths) or image slicers (which give feasible but still large instruments). Here we develop the solution proposed by Bland-Hawthorn and Horton: the use of diffraction-limited spectrographs which are compact even for high resolving power. Their use is made possible by the photonic lantern, which splits a multi-mode optical fiber into a number of single-mode fibers. We describe preliminary designs for such spectrographs, at a resolving power of R ~ 50,000. While they are small and use relatively simple optics, the challenges are to accommodate the longest possible fiber slit (hence maximum number of single-mode fibers in one spectrograph) and to accept the beam from each fiber at a focal ratio considerably faster than for most spectrograph collimators, while maintaining diffraction-limited imaging quality. It is possible to obtain excellent performance despite these challenges. We also briefly consider the number of such spectrographs required, which can be reduced by full or partial adaptive optics correction, and/or moving towards longer wavelengths.

  15. Deployable Integral Field Units, Multislits, and Image Slicer for the Goodman Imaging Spectrograph on the SOAR Telescope

    Science.gov (United States)

    Cecil, Gerald N.; Moffett, A. J.; Cui, Y.; Eckert, K. D.; McBride, J.; Kannappan, S.; Keller, K.; Barlow, B. N.; Dunlap, B.; Bland-Hawthorn, J.

    2010-01-01

    The Goodman Imager-Spectrograph on the 4.1m SOAR telescope has operated on Cerro Pachon, Chile with volume-phase holographic gratings in long-slit mode since its commissioning in 2008. Recently, UNC graduate students played key roles to implement robust upgrades for multi-object spectroscopy that will soon be available to US astronomers through the NOAO time share on SOAR: • Multislits over 3x5 arcmin, generated on PCB solder stencils with exceptional sharpness compared to conventional laser cuts, initially to survey globular clusters for pulsating hot sub-dwarfs • An image slicer to obtain 3 simultaneous parallel spectra 70-arcsec long, 1- or 2-arcsec wide, spanning 320-750 nm to map stellar and gaseous emission and mass over the 1500 galaxies in the RESOLVE survey underway on SOAR • Four integral field units, each composed of 5-arcsec diameter, fused bundles of 0.5-arcsec diameter thin-clad optical fiber, independently deployed over a 10x5 arcmin field targeted by an EMCCD also used for Lucky Imaging. Initially will study aperture effects in single fiber surveys, extragalactic globular clusters, and demonstrate technology prior to deployment on larger telescopes • New wheels supporting a large set of existing narrow-band and Sloan filters • A trombone-style atmospheric dispersion compensator that corrects the full 12-arcmin diameter science field down to 30 deg elevation. Working in UNC's Goodman Laboratory for Astronomical Instrumentation, students employed SolidWorks and ZEMAX to design parts for in-house CAM on CNC machines and a 3D printer. All motors are controlled by LabVIEW as is the SOAR TCS. The deployable IFU axes are controlled by Quicksilver Controls Inc. intelligent servos and $80 model robot (Firgelli Corp.) actuators driven by a PIC-microcontroller and a student designed custom PCB. Upgrades and students were supported by $200K from SOAR Corporation, Research Corporation, NSF, and UNC competitive funds, and NC NASA Space Grant, Sigma Xi

  16. Radio Astronomical Polarimetry and the Lorentz Group

    OpenAIRE

    Britton, M. C.

    1999-01-01

    In radio astronomy the polarimetric properties of radiation are often modified during propagation and reception. Effects such as Faraday rotation, receiver cross-talk, and differential amplification act to change the state of polarized radiation. A general description of such transformations is useful for the investigation of these effects and for the interpretation and calibration of polarimetric observations. Such a description is provided by the Lorentz group, which is intimately related t...

  17. NRAO Astronomer Wins Prestigious Guggenheim Fellowship

    Science.gov (United States)

    2010-04-01

    Dr. Dale Frail, an astronomer at the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, has been awarded a prestigious Guggenheim Fellowship, according to the John Simon Guggenheim Memorial Foundation. The Guggenheim Foundation describes its fellowships as "mid-career" awards "intended for men and women who have already demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the arts." Frail, 48, has worked at the NRAO for more than 20 years, first as a postdoctoral fellow, and then as a staff scientist. He received his bachelor's degree in physics from Acadia University in Nova Scotia, and his Ph.D in astronomy from the University of Toronto. Frail is best known for his landmark contributions to the understanding of gamma ray bursts, making critical measurements that provided key insights into the mechanisms of these superenergetic and once-mysterious explosions. He also has made important contributions to the understanding of other astronomical phenomena, including pulsars and their neighborhoods, supernova remnants, and magnetars. In 1992, he was the co-discoverer, with Alex Wolszczan, of the first planets outside our own solar system. "We congratulate Dale on this well-deserved honor that recognizes not only his past achievements but also his potential for exciting scientific work in the future," said Dr. Fred K.Y. Lo, NRAO Director. "We're very proud to see one of our scientists receive such a great honor," Lo added. Frail is one of 180 recipients of this year's Guggenheim Fellowships, chosen from some 3,000 applicants. The fellowships were established in 1925 and past recipients include photographer Ansel Adams, author Saul Bellow, former Secretary of State Henry Kissinger, and chemist Linus Pauling. 102 Guggenheim Fellows have subsequently won Nobel Prizes, and others have received Pulitzer Prizes and other honors. As a Guggenheim Fellow, Frail intends to intensify his research in the areas of pulsars

  18. Residual gas analyzer calibration

    Science.gov (United States)

    Lilienkamp, R. H.

    1972-01-01

    A technique which employs known gas mixtures to calibrate the residual gas analyzer (RGA) is described. The mass spectra from the RGA are recorded for each gas mixture. This mass spectra data and the mixture composition data each form a matrix. From the two matrices the calibration matrix may be computed. The matrix mathematics requires the number of calibration gas mixtures be equal to or greater than the number of gases included in the calibration. This technique was evaluated using a mathematical model of an RGA to generate the mass spectra. This model included shot noise errors in the mass spectra. Errors in the gas concentrations were also included in the valuation. The effects of these errors was studied by varying their magnitudes and comparing the resulting calibrations. Several methods of evaluating an actual calibration are presented. The effects of the number of gases in then, the composition of the calibration mixture, and the number of mixtures used are discussed.

  19. Book Review: Scientific Writing for Young Astronomers

    Science.gov (United States)

    Uyttenhove, Jos

    2011-12-01

    EDP Sciences, Les Ulis, France. Part 1 : 162 pp. € 35 ISBN 978-2-7598-0506-8 Part 2 : 298 pp. € 60 ISBN 978-2-7598-0639-3 The journal Astronomy & Astrophysics (A&A) and EDP Sciences decided in 2007 to organize a School on the various aspects of scientific writing and publishing. In 2008 and 2009 Scientific Writing for Young Astronomers (SWYA) Schools were held in Blankenberge (B) under the direction of Christiaan Sterken (FWO-VUB). These two books (EAS publication series, Vol. 49 and 50) reflect the outcome of these Schools. Part 1 contains a set of contributions that discuss various aspects of scientific publication; it includes A&A Editors' view of the peer review and publishing process. A very interesting short paper by S.R. Pottasch (Kapteyn Astronomical Institute, Groningen, and one of the two first Editors-in Chief of A&A) deals with the history of the creation of the journal Astronomy & Astrophysics. Two papers by J. Adams et al. (Observatoire de Paris) discuss language editing, including a detailed guide for any non-native user of the English language. In 2002 the Board of Directors decided that all articles in A&A must be written in clear and correct English. Part 2 consists of three very extensive and elaborated papers by Christiaan Sterken, supplying guidelines to PhD students and postdoctoral fellows to help them compose scientific papers for different forums (journals, proceedings, thesis, etc.). This part is of interest not only for young astronomers but it is very useful for scholars of all ages and disciplines. Paper I "The writing process" (60 pp.) copes with the preparation of manuscripts, with communicating with editors and referees and with avoiding common errors. Delicate problems on authorship, refereeing, revising multi-authored papers etc. are treated in 26 FAQ's. Paper II "Communication by graphics" (120 pp.) is entirely dedicated to the important topic of communication with images, graphs, diagrams, tables etc. Design types of graphs

  20. Model based systems engineering for astronomical projects

    Science.gov (United States)

    Karban, R.; Andolfato, L.; Bristow, P.; Chiozzi, G.; Esselborn, M.; Schilling, M.; Schmid, C.; Sommer, H.; Zamparelli, M.

    2014-08-01

    Model Based Systems Engineering (MBSE) is an emerging field of systems engineering for which the System Modeling Language (SysML) is a key enabler for descriptive, prescriptive and predictive models. This paper surveys some of the capabilities, expectations and peculiarities of tools-assisted MBSE experienced in real-life astronomical projects. The examples range in depth and scope across a wide spectrum of applications (for example documentation, requirements, analysis, trade studies) and purposes (addressing a particular development need, or accompanying a project throughout many - if not all - its lifecycle phases, fostering reuse and minimizing ambiguity). From the beginnings of the Active Phasing Experiment, through VLT instrumentation, VLTI infrastructure, Telescope Control System for the E-ELT, until Wavefront Control for the E-ELT, we show how stepwise refinements of tools, processes and methods have provided tangible benefits to customary system engineering activities like requirement flow-down, design trade studies, interfaces definition, and validation, by means of a variety of approaches (like Model Checking, Simulation, Model Transformation) and methodologies (like OOSEM, State Analysis)

  1. Astronomical Forcing of Salt Marsh Biogeochemical Cascades

    Science.gov (United States)

    Morris, J. T.; Sundberg, K.

    2008-12-01

    Astronomically forced changes in the hydroperiod of a salt marsh affect the rate of marsh primary production leading to a biogeochemical cascade. For example, salt marsh primary production and biogeochemical cycles in coastal salt marshes are sensitive to the 18.6-year lunar nodal cycle, which alters the tidal amplitude by about 5 cm. For marshes that are perched high in the tidal frame, a relatively small increase in tidal amplitude and flooding lowers sediment salinity and stimulates primary production. Porewater sulfide concentrations are positively correlated with tidal amplitude and vary on the same cycle as primary production. Soluble reactive phosphate and ammonium concentrations in pore water also vary on this 18.6- year cycle. Phosphate likely responds to variation in the reaction of sulfide with iron-phosphate compounds, while the production of ammonium in sediments is coupled to the activity of diazotrophs that are carbon- limited and, therefore, are regulated by primary productivity. Ammonium also would accumulate when sulfides block nitrification. These dependencies work as a positive feedback between primary production and nutrient supply and are predictive of the near-term effects of sea-level rise.

  2. Is astronomical research appropriate for developing countries?

    Science.gov (United States)

    Snowden, Michael S.

    An unproductive 45-cm astronomical telescope, given by JICA (Japan) to Sri Lanka, raises general questions as to the reasons for unproductive pure science in developing countries. Before installation, site, maintenance, and scientific objectives were discussed. The facility was launched with a conference organised by the UN Office for Outer Space Affairs. Unfortunately, no research or significant education has resulted after four years. The annual operating cost is U.S. $5000 per year, including salary for a trainee, maintenance, and a modest promotional programme. Comparison with a similar installation in Auckland suggests lack of funding or technical competence do not explain the failure in Sri Lanka. The facility in New Zealand, on the roof of Auckland University's Physics Department, has a slightly smaller budget but has led to modest but useful research and teaching. Lack of financial backing and expertise are often blamed for weak science in developing countries, but examination shows most of these countries have adequately skilled people, and plenty of resources for religion and military. General lack of motivation for science appears to be the principal reason. This lack of interest and highly inefficient bureaucracies are common to scientifically unproductive countries. They mostly lack the cultural and philosophical base of the European Renaissance that motivate the pursuit of modern science, an activity that violates human preferences. There are excellent facilities (ESO, SAAO, Cerro Tololo, and GONG) in some of these same countries, when administered from the West.

  3. Compact Stirling cooling of astronomical detectors

    CERN Document Server

    Raskin, Gert; Pessemier, Wim; Padilla, Jesus Perez; Vandersteen, Jeroen

    2013-01-01

    MAIA, a three-channel imager targeting fast cadence photometry, was recently installed on the Mercator telescope (La Palma, Spain). This instrument observes a 9.4 x 14.1 arcmin field of view simultaneously in three color bands ($u$, $g$ and $r$), using three of the largest (un-) available frame-transfer CCDs, namely the 2k x 6k CCD42-C0 from e2v. As these detectors are housed in three separate cryostats, compact cooling devices are required that offer sufficient power to cool the large chips to a temperature of 165K. We explored a broad spectrum of cooling options and technologies to cool the MAIA detectors. Finally, compact free-piston Stirling coolers were selected, namely the CryoTel MT cryo-coolers from SUNPOWER, that can extract 5W of heat at a temperature of 77K. In this contribution we give details of the MAIA detector cooling solution. We also discuss the general usability of this type of closed-cycle cryo-coolers for astronomical detectors. They offer distinct advantages but the vibrations caused by ...

  4. The Taiwan Extragalactic Astronomical Data Center

    CERN Document Server

    Foucaud, Sébastien; Tsai, Meng-Feng; Kamennoff, Nicolas

    2012-01-01

    Founded in 2010, the Taiwan Extragalactic Astronomical Data Center (TWEA-DC) has for goal to propose access to large amount of data for the Taiwanese and International community, focusing its efforts on Extragalactic science. In continuation with individual efforts in Taiwan over the past few years, this is the first steppingstone towards the building of a National Virtual Observatory. Taking advantage of our own fast indexing algorithm (BLINK), based on a octahedral meshing of the sky coupled with a very fast kd-tree and a clever parallelization amongst available resources, TWEA-DC will propose from spring 2013 a service of "on-the-fly" matching facility, between on-site and user-based catalogs. We will also offer access to public and private raw and reducible data available to the Taiwanese community. Finally, we are developing high-end on-line analysis tools, such as an automated photometric redshifts and SED fitting code (APz), and an automated groups and clusters finder (APFoF).

  5. The Research Use of Astronomical Monographs

    Science.gov (United States)

    Abt, Helmut A.

    2014-04-01

    I explored the use of astronomical monographs used for research. After scanning 135 monographs (excluding conference proceedings and textbooks) listed in 2000-2003 issues of Physics Today and counting citations of them in 2000-2013 in ADS (Astrophysics Data System), I found that 67% of the monographs received fewer than 2 citations per year. The average citation rate for the 135 monographs is statistically the same as for ApJ papers. In contrast, only 41% of the ApJ papers produce fewer than 2 citations per year. ADS also counts the number of times each book or paper is read on-line. The average in 14 years is 181 ± 27 times for the monographs and 633 ± 47 times for ApJ papers. The total numbers of citations in 14 years for the monographs ranged from 0 to 711. I explored reasons for this range and only learned that it did not depend on (1) the numbers of book reviews published or (2) the scientific stature of the authors. I am unable to predict whether a monograph will be successful or not. The decreasing of references to monographs seems to be due to (1) monographs becoming so expensive that individuals and libraries cannot afford many of them, (2) readers seeming to prefer concise reviews, such as online searches and the Annual Reviews, and (3) most of the monographs having not been available free online.

  6. Calibration of the Solar Orbiter Energetic Particle Detector Suite

    Science.gov (United States)

    Wimmer-Schweingruber, R. F.; Rodriguez-Pacheco, J.; Martin-Garcia, C.; Kulkarni, S. R.; Panitzsch, L.; Boettcher, S.; Mason, G. M.; Kohler, J.; Ho, G. C.; Boden, S.; Grunau, J.; Steinhagen, J.; Terasa, C.; Yu, J.; Prieto, M.; Gomez-Herrero, R.; Blanco, J.

    2013-12-01

    We present the current status and plans for the calibration of the Energetic Particle Detector (EPD) suite on ESA's Solar Orbiter mission. Solar Orbiter is scheduled to launch in January 2017, instrument delivery in January 2015. EPD consists of four sensors: the SupraThermal Electron and Proton (STEP) sensor covers electrons (protons) from 2 (3) keV up to 100 keV, the Electron Proton Telescope (EPT) from 20 to 300 (7000) keV, the Suprathermal Ion Spectrograph (SIS) determines the ionic composition from ~0.05 to ~10 MeV/nuc (species dependent), and the High Energy Telescope (HET) measures electrons and protons (ions) from 0.3 to 30 and 10 to >100 MeV/nuc (20 - 200 MeV/nuc species dependent). EPT, HET, and SIS have two approximately opposite-facing fields of view, EPT, and HET share a common electronics box, two EPT/HET sensors allow the determination of second-order anisotropies (a total of 4 FoVs). Apart from the use of radioactive sources, STEP will be calibrated at the Kiel calibration facilities, EPT both at Kiel (electrons and low-energy protons) as well as at PTB in Braunschweig. SIS will undergo calibration at the LBL 88' cyclotron, HET at HIMAC in Chiba, Japan. Tests of the electron/protons discrimination of EPT show the expected behavior, HET prototypes have already been calibrated and the results will be shown.

  7. Precision Spectrophotometric Calibration System for Dark Energy Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Schubnell, Michael S.

    2015-06-30

    For this research we build a precision calibration system and carried out measurements to demonstrate the precision that can be achieved with a high precision spectrometric calibration system. It was shown that the system is capable of providing a complete spectrophotometric calibration at the sub-pixel level. The calibration system uses a fast, high precision monochromator that can quickly and efficiently scan over an instrument’s entire spectral range with a spectral line width of less than 0.01 nm corresponding to a fraction of a pixel on the CCD. The system was extensively evaluated in the laboratory. Our research showed that a complete spectrophotometric calibration standard for spectroscopic survey instruments such as DESI is possible. The monochromator precision and repeatability to a small fraction of the DESI spectrograph LSF was demonstrated with re-initialization on every scan and thermal drift compensation by locking to multiple external line sources. A projector system that mimics telescope aperture for point source at infinity was demonstrated.

  8. The Virtual Astronomical Observatory: Re-engineering access to astronomical data

    Science.gov (United States)

    Hanisch, R. J.; Berriman, G. B.; Lazio, T. J. W.; Emery Bunn, S.; Evans, J.; McGlynn, T. A.; Plante, R.

    2015-06-01

    The US Virtual Astronomical Observatory was a software infrastructure and development project designed both to begin the establishment of an operational Virtual Observatory (VO) and to provide the US coordination with the international VO effort. The concept of the VO is to provide the means by which an astronomer is able to discover, access, and process data seamlessly, regardless of its physical location. This paper describes the origins of the VAO, including the predecessor efforts within the US National Virtual Observatory, and summarizes its main accomplishments. These accomplishments include the development of both scripting toolkits that allow scientists to incorporate VO data directly into their reduction and analysis environments and high-level science applications for data discovery, integration, analysis, and catalog cross-comparison. Working with the international community, and based on the experience from the software development, the VAO was a major contributor to international standards within the International Virtual Observatory Alliance. The VAO also demonstrated how an operational virtual observatory could be deployed, providing a robust operational environment in which VO services worldwide were routinely checked for aliveness and compliance with international standards. Finally, the VAO engaged in community outreach, developing a comprehensive web site with on-line tutorials, announcements, links to both US and internationally developed tools and services, and exhibits and hands-on training at annual meetings of the American Astronomical Society and through summer schools and community days. All digital products of the VAO Project, including software, documentation, and tutorials, are stored in a repository for community access. The enduring legacy of the VAO is an increasing expectation that new telescopes and facilities incorporate VO capabilities during the design of their data management systems.

  9. The Double Didactic Astronomical Quadrant for the XIII International Astronomical Olympiad

    CERN Document Server

    Maris, Michele; Boehm, Conrad; Iafrate, Giulia; Ramella, Massimo

    2010-01-01

    Here we present the development of a simplified version of double astronomical quadrant, designed for educational aims and realized on the occasion of the observational round of the XIII International Astronomy Olympiad, held in Trieste (Italy) October 13-21, 2008. (Italia: In questo contributo illustriamo il progetto di una versione semplificata di doppio quadrante astronomico, progettato per fini didattici e realizzato in occasione dello svolgimento della gara osservativa delle XIII Olimpiadi Internazionali di Astronomia (XIII International Astronomy Olympiad, XIII IAO), Trieste (I), 13-21 ottobre 2008))

  10. Astronomical Masers: Polarization Properties of 22-GHZ Water and 6.7-GHZ Methanol Masers.

    Science.gov (United States)

    Surcis, Gabriele; Vlemmings, Wouter H. T.; van Langevelde, Huib Jan

    2014-06-01

    By observing the astronomical masers in the Milky Way we can determine for instance high-accurate distances of the hosting Galactic sources (e.g., Galactic star-forming regions) and the kinematic of the gas where the masers arise (e.g., the kinematic of Keplerian accretion disks and outflows in massive star-forming regions). In addition, the bright and narrow spectral line emissions of water and methanol masers are ideal for measuring the Zeeman splitting as well as for determining the orientation of the magnetic field in 3-dimensions around massive young stellar objects (YSOs). Therefore, water and methanol maser species can help us to answer several crucial questions about massive star-formation. For instance, one of the most debated question is whether magnetic fields are important in the formation of high-mass stars (M>8 {Msun}). The main difficulty in answering this question is related to the fast evolution of the high-mass stars that makes the massive YSOs rare. Furthermore, they are typically found at fairly large distance. Hence, it is very difficult to measure the magnetic fields at distances 100 Astronomical Units from the central protostar by using dust polarized emissions. But fortunately, the direct measurement of magnetic fields at small scale (10-100 Astronomical Units) around massive YSOs is possible by observing the polarized emission of masers. In my oral contribution, besides showing the polarization properties of 22-GHz water and 6.7-GHz methanol masers, I will show our most interesting results about the determination of the orientation and of the strength of magnetic fields around massive YSOs. We have also started a systematic study for determining if there exists a real alignment between magnetic fields and the large scale outflows that are launched from the central protostar, which is important to constrain future simulations. Furthermore, we are involved in laboratory and modelling efforts to calibrate the magnitude of the Zeeman effect for

  11. Architecture and performance of astronomical adaptive optics systems

    Science.gov (United States)

    Bloemhof, E.

    2002-01-01

    In recent years the technological advances of adaptive optics have enabled a great deal of innovative science. In this lecture I review the system-level design of modern astronomical AO instruments, and discuss their current capabilities.

  12. Relying on electronic journals: Reading patterns of astronomers

    Science.gov (United States)

    Tenopir, Carol; King, Donald W.; Boyce, Peter; Grayson, Matt; Paulson, Keri-Lynn

    2005-06-01

    Surveys of the members of the American Astronomical Society identify how astronomers use journals and what features and formats they prefer. While every work field is distinct, the patterns of use by astronomers may provide a glimpse of what to expect of journal patterns and use by other scientists. Astronomers, like other scientists, continue to invest a large amount of their time in reading articles and place a high level of importance on journal articles. They use a wide variety of formats and means to get access to materials that are essential to their work in teaching, service, and research. They select access means that are convenient - whether those means be print, electronic, or both. The availability of a mature electronic journals system from their primary professional society has surely influenced their early adoption of e-journals.

  13. The Persian-Toledan Astronomical Connection and the European Renaissance

    CERN Document Server

    Heydari-Malayeri, M

    2007-01-01

    This paper aims at presenting a brief overview of astronomical exchanges between the Eastern and Western parts of the Islamic world from the 8th to 14th century. These cultural interactions were in fact vaster involving Persian, Indian, Greek, and Chinese traditions. I will particularly focus on some interesting relations between the Persian astronomical heritage and the Andalusian (Spanish) achievements in that period. After a brief introduction dealing mainly with a couple of terminological remarks, I will present a glimpse of the historical context in which Muslim science developed. In Section 3, the origins of Muslim astronomy will be briefly examined. Section 4 will be concerned with Khwarizmi, the Persian astronomer/mathematician who wrote the first major astronomical work in the Muslim world. His influence on later Andalusian astronomy will be looked into in Section 5. Andalusian astronomy flourished in the 11th century, as will be studied in Section 6. Among its major achievements were the Toledan Tab...

  14. A Multilingual on-line Dictionary of Astronomical Concepts

    CERN Document Server

    Heydari-Malayeri, M

    2009-01-01

    On the occasion of the International Year of Astronomy (IYA2009), we present a new interactive dictionary of astronomy and astrophysics, which contains about 7000 entries. This interdisciplinary and multicultural work is intended for professional and amateur astronomers, university students in astrophysics, as well as terminologists and linguists. A new approach is pursued in the formation of a scientific dictionary, which aims to display additional dimensions of astronomical concepts. Although Virtual Observatories recognize the necessity of efforts to define basic astronomical concepts and establish their reciprocal relations, so far they have mainly been confined to archiving observational data. The present dictionary could be an incipient contribution to cover and inter-relate the whole astronomical lexicon beyond subfields.

  15. Lessons from the masters current concepts in astronomical image processing

    CERN Document Server

    2013-01-01

    There are currently thousands of amateur astronomers around the world engaged in astrophotography at increasingly sophisticated levels. Their ranks far outnumber professional astronomers doing the same and their contributions both technically and artistically are the dominant drivers of progress in the field today. This book is a unique collaboration of individuals, all world-renowned in their particular area, and covers in detail each of the major sub-disciplines of astrophotography. This approach offers the reader the greatest opportunity to learn the most current information and the latest techniques directly from the foremost innovators in the field today.   The book as a whole covers all types of astronomical image processing, including processing of eclipses and solar phenomena, extracting detail from deep-sky, planetary, and widefield images, and offers solutions to some of the most challenging and vexing problems in astronomical image processing. Recognized chapter authors include deep sky experts su...

  16. The Educational Activities of the Astronomical Society of the Pacific.

    Science.gov (United States)

    Fraknoi, Andrew

    1981-01-01

    Describes educational activities of the Astronomical Society of the Pacific including learning packets on various astronomy concepts, Morrison lectures, newspaper columns, teacher workshops, cosponsoring astronomy oriented lectures, and providing speakers for various groups. (DS)

  17. PPARC: Grid technology helps astronomers keep pace with the Universe

    CERN Multimedia

    2003-01-01

    "Intelligent Agent" computer programs are roaming the Internet and watching the skies. These programs, using Grid computing technology, will help astronomers detect some of the most dramatic events in the universe, such as massive supernova explosions (1 page).

  18. Astronomical Software Wants To Be Free: A Manifesto

    CERN Document Server

    Weiner, Benjamin J; Coil, Alison L; Cooper, Michael C; Davé, Romeel; Hogg, David W; Holden, Bradford P; Jonsson, Patrik; Kassin, Susan A; Lotz, Jennifer M; Moustakas, John; Newman, Jeffrey A; Prochaska, J X; Teuben, Peter J; Tremonti, Christy A; Willmer, Christopher N A

    2009-01-01

    Astronomical software is now a fact of daily life for all hands-on members of our community. Purpose-built software for data reduction and modeling tasks becomes ever more critical as we handle larger amounts of data and simulations. However, the writing of astronomical software is unglamorous, the rewards are not always clear, and there are structural disincentives to releasing software publicly and to embedding it in the scientific literature, which can lead to significant duplication of effort and an incomplete scientific record. We identify some of these structural disincentives and suggest a variety of approaches to address them, with the goals of raising the quality of astronomical software, improving the lot of scientist-authors, and providing benefits to the entire community, analogous to the benefits provided by open access to large survey and simulation datasets. Our aim is to open a conversation on how to move forward. We advocate that: (1) the astronomical community consider software as an integra...

  19. The Cassini Campaign observations of the Jupiter aurora by the Ultraviolet Imaging Spectrograph and the Space Telescope Imaging Spectrograph

    Science.gov (United States)

    Ajello, Joseph M.; Pryor, Wayne; Esposito, Larry; Stewart, Ian; McClintock, William; Gustin, Jacques; Grodent, Denis; Gérard, J.-C.; Clarke, John T.

    2005-11-01

    We have analyzed the Cassini Ultraviolet Imaging Spectrometer (UVIS) observations of the Jupiter aurora with an auroral atmosphere two-stream electron transport code. The observations of Jupiter by UVIS took place during the Cassini Campaign. The Cassini Campaign included support spectral and imaging observations by the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS). A major result for the UVIS observations was the identification of a large color variation between the far ultraviolet (FUV: 1100-1700 Å) and extreme ultraviolet (EUV: 800-1100 Å) spectral regions. This change probably occurs because of a large variation in the ratio of the soft electron flux (10-3000 eV) responsible for the EUV aurora to the hard electron flux (˜15-22 keV) responsible for the FUV aurora. On the basis of this result a new color ratio for integrated intensities for EUV and FUV was defined ( 4πI/4πI) which varied by approximately a factor of 6. The FUV color ratio ( 4πI/4πI) was more stable with a variation of less than 50% for the observations studied. The medium resolution (0.9 Å FWHM, G140M grating) FUV observations (1295-1345 Å and 1495-1540 Å) by STIS on 13 January 2001, on the other hand, were analyzed by a spectral modeling technique using a recently developed high-spectral resolution model for the electron-excited H 2 rotational lines. The STIS FUV data were analyzed with a model that considered the Lyman band spectrum (B Σu+1→XΣg+1) as composed of an allowed direct excitation component (X Σg+1→BΣu+1) and an optically forbidden component (X Σg+1→EF,GK,HH¯,…Σg+1 followed by the cascade transition Σg+1→BΣu+1). The medium-resolution spectral regions for the Jupiter aurora were carefully chosen to emphasize the cascade component. The ratio of the two components is a direct measurement of the mean secondary electron energy of the aurora. The mean secondary electron energy of the aurora varies between 50 and 200 eV for the polar

  20. Young Astronomers' Observe with ESO Telescopes

    Science.gov (United States)

    1995-11-01

    Today, forty 16-18 year old students and their teachers are concluding a one-week, educational `working visit' to the ESO Headquarters in Garching (See ESO Press Release 14/95 of 8 November 1995). They are the winners of the Europe-wide contest `Europe Towards the Stars', organised by ESO with the support of the European Union, under the auspices of the Third European Week for Scientific and Technological Culture. From November 14-20, they have worked with professional ESO astronomers in order to get insight into the methods and principles of modern astronomy and astrophysics, as carried out at one of the world's foremost international centres. This included very successful remote observations with the ESO 3.5-m New Technology Telescope (NTT) and the 1.4-m Coude Auxiliary Telescope (CAT) via a satellite link between the ESO Headquarters and the La Silla observatory in Chile, 12,000 kilometres away. After a general introduction to modern astronomy on the first day of the visit, the participants divided into six teams, according to their interests. Some chose to observe distant galaxies, others prefered to have a closer look on binary stars, and one team decided to investigate a star which is thought to be surrounded by a proto-planetary system. Each team was supported by an experienced ESO astronomer. Then followed the observations at the remote consoles during three nights, the first at the NTT and the following at the CAT. Each team had access to the telescope during half a night. Although the work schedule - exactly as in `real' science - was quite hard, especially during the following data reduction and interpretative phase, all teams managed extremely well and in high spirits. The young astronomers' observations were favoured by excellent atmospheric conditions. At the NTT, the seeing was better than 0.5 arcsecond during several hours, an exceptional value that allows very good images to be obtained. All observations represent solid and interesting science, and

  1. Some early astronomical sites in the Kashmir region

    Science.gov (United States)

    Iqbal, Naseer; Vahia, M. N.; Masood, Tabasum; Ahmad, Aijaz

    2009-03-01

    We discuss a number of early rock art sites in the Kashmir Valley in northern India and neighbouring Pakistan, and suggest that some of these contain depictions of astronomical objects or events. The sites are in the Srinagar and Sopore regions and in or near the Ladakh region, and date to Neolithic or Upper Paleolithic times. Our studies suggest that during this period some of the ancient astronomers recorded supernovae, meteorite impacts, the Sun, the Moon and the seasons in their rock art.

  2. Real-time earthquake warning for astronomical observatories

    CERN Document Server

    Coughlin, Michael; Barrientos, Sergio; Claver, Chuck; Harms, Jan; Smith, Christopher; Warner, Michael

    2014-01-01

    Early earthquake warning is a rapidly developing capability that has significant ramifications for many fields, including astronomical observatories. In this work, we describe the susceptibility of astronomical facilities to seismic events, including large telescopes as well as second-generation ground-based gravitational-wave interferometers. We describe the potential warning times for observatories from current seismic networks and propose locations for future seismometers to maximize warning times.

  3. A Survey for Transient Astronomical Radio Emission at 611 MHz

    OpenAIRE

    Katz, C. A.; Hewitt, J. N.; Corey, B. E.; Moore, C. B.

    2003-01-01

    We have constructed and operated the Survey for Transient Astronomical Radio Emission (STARE) to detect transient astronomical radio emission at 611 MHz originating from the sky over the northeastern United States. The system is sensitive to transient events on timescales of 0.125 s to a few minutes, with a typical zenith flux density detection threshold of approximately 27 kJy. During 18 months of around-the-clock observing with three geographically separated instruments, we detected a total...

  4. Blowing bubbles in the cosmos astronomical winds, jets, and explosions

    CERN Document Server

    Hartquist, T W; Ruffle, D P

    2004-01-01

    1. The First Discoveries of Astronomical Winds2. The Magnitudes of Astronomical Quantities3. Stellar Evolution4. Basic Structures of Winds and Windblown Bubbles5. Star Formation and Low-Mass Young Stellar Objects6. Regions of High-Mass Star Formation7. Winds from Main-Sequence and Post-Main-Sequence Stars8. Supernovae and Their Remnants9. Galactic Winds, Starburst Superwinds, and the Epoch of Galaxy Formation10. Active Galaxies and Their Nuclei11. Some Other Windy and Explosive Sources

  5. ASTRONOMICAL ALGORITHMS OF EGYPTIAN PYRAMIDS SLOPES AND THEIR MODULES DIVIDER

    OpenAIRE

    Aboulfotouh, Hossam M. K.

    2015-01-01

    This paper is an attempt to show the astronomical design principles that are encoded in the geometrical forms of the largest five pyramids of the fourth Egyptian dynasty, in Giza and Dahshur plateaus, based on using the pyramids’ design-modules that are mentioned in the so-called Rhind Mathematical Papyrus. It shows the astronomical algorithms for quantifying the slopes of pyramids, with reference to specific range of earth’s axial tilt, within spherical co-ordinates system. Besid...

  6. New developments at the NASA Astronomical Data Center

    Science.gov (United States)

    Warren, W. H., Jr.

    1985-01-01

    The need for a compilation catalog containing a large variety of astronomical data for the Astronomical Data Base of NASA is considered. It is suggested that the catalog should be prepared directly from the SIMBAD data base by processing through a single software program and made available for distribution on magnetic tape or microfilm. Annual updating is recommended to ensure the quality of the catalog. Data recommended for inclusion in the compilation catalog are listed in a table.

  7. A student assembled spectrograph with a CCD detector to assist with students' understanding of spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grove, T T; Masters, M F [Physics Department, Indiana University-Purdue University Fort Wayne, Fort Wayne, IN 46805 (United States)

    2007-07-15

    To help students develop an understanding of the proper use and function of spectrographs and monochromators we describe a student-assembled spectrograph using a 'webcam' detector. The apparatus also works well as a low-cost demonstration, helping students make connections between an atomic spectrum observed by eye and a plot of the relative intensity versus wavelength. It also allows students to observe the internal components of a spectrograph.

  8. LRS2: the new facility low resolution integral field spectrograph for the Hobby-Eberly Telescope

    CERN Document Server

    Chonis, Taylor S; Lee, Hanshin; Tuttle, Sarah E; Vattiat, Brian L

    2014-01-01

    The second generation Low Resolution Spectrograph (LRS2) is a new facility instrument for the Hobby-Eberly Telescope (HET). Based on the design of the Visible Integral-field Replicable Unit Spectrograph (VIRUS), which is the new flagship instrument for carrying out the HET Dark Energy Experiment (HETDEX), LRS2 provides integral field spectroscopy for a seeing-limited field of 12 x 6 arcseconds. For LRS2, the replicable design of VIRUS has been leveraged to gain broad wavelength coverage from 370 nm to 1 micron, spread between two fiber-fed dual-channel spectrographs, each of which can operate as an independent instrument. The blue spectrograph, LRS2-B, covers 370-470 nm and 460-700 nm at fixed resolving powers of ~1900 and ~1100, respectively, while the red spectrograph, LRS2-R, covers 650-842 nm and 818-1050 nm with both of its channels having a resolving power of ~1800. In this paper, we present a detailed description of the instrument's design in which we focus on the departures from the basic VIRUS framew...

  9. Adaptive optics for high resolution spectroscopy: A direct application with the future NIRPS spectrograph

    CERN Document Server

    Conod, Uriel; Wildi, François; Pepe, Francesco

    2016-01-01

    Radial velocity instruments require high spectral resolution and extreme thermo-mecanical stability, even more difficult to achieve in near-infra red (NIR) where the spectrograph has to be cooled down. For a seeing-limited spectrograph, the price of high spectral resolution is an increased instrument volume, proportional to the diameter of the primary mirror. A way to control the size, cost, and stability of radial velocity spectrographs is to reduce the beam optical etendue thanks to an Adaptive Optics (AO) system. While AO has revolutionized the field of high angular resolution and high contrast imaging during the last 20 years, it has not yet been (successfully) used as a way to control spectrographs size, especially in the field of radial velocities. In this work we present the AO module of the future NIRPS spectrograph for the ESO 3.6 m telescope, that will be feed with multi-mode fibers. We converge to an AO system using a Shack-Hartmann wavefront sensor with 14x14 subapertures, able to feed 50% of the ...

  10. Realization of High Dynamic Range Imaging in the GLORIA Network and Its Effect on Astronomical Measurement

    Directory of Open Access Journals (Sweden)

    Stanislav Vítek

    2016-01-01

    Full Text Available Citizen science project GLORIA (GLObal Robotic-telescopes Intelligent Array is a first free- and open-access network of robotic telescopes in the world. It provides a web-based environment where users can do research in astronomy by observing with robotic telescopes and/or by analyzing data that other users have acquired with GLORIA or from other free-access databases. Network of 17 telescopes allows users to control selected telescopes in real time or schedule any more demanding observation. This paper deals with new opportunity that GLORIA project provides to teachers and students of various levels of education. At the moment, there are prepared educational materials related to events like Sun eclipse (measuring local atmosphere changes, Aurora Borealis (calculation of Northern Lights height, or transit of Venus (measurement of the Earth-Sun distance. Student should be able to learn principles of CCD imaging, spectral analysis, basic calibration like dark frames subtraction, or advanced methods of noise suppression. Every user of the network can design his own experiment. We propose advanced experiment aimed at obtaining astronomical image data with high dynamic range. We also introduce methods of objective image quality evaluation in order to discover how HDR methods are affecting astronomical measurements.

  11. Strange Cases from the Files of Astronomical Sociology

    CERN Document Server

    Krisciunas, K

    1993-01-01

    What astronomer could not use his own surname because his father was beheaded for sorcery? Who built the only observatory worth $5 billion in today's money? Who had worse luck than YOU travelling thousands of miles NOT to observe an astronomical event? Who had one of his books bound in human skin at the request of his most ardent fan? Is there an anti-correlation between scientific output and the number of children one has? Are astronomers known for having unusual honeymoons? Who wrote the most egotistical work in the history of astronomy? What famous astronomer was present for the opening of King Tutankhamen's tomb and later began having hallucinations of an elf, which advised him on the running of his observatory? What is the strangest abstract published in the Bulletin of the American Astronomical Society? What well-known bad tempered astronomer was born in 1898 (the year after Bram Stoker's {\\em Dracula} was published) in Varna, Bulgaria, which all vampirologists recognize as the nearest port from which a...

  12. The Palomar Kernel Phase Experiment: Testing Kernel Phase Interferometry for Ground-based Astronomical Observations

    CERN Document Server

    Pope, Benjamin; Hinkley, Sasha; Ireland, Michael J; Greenbaum, Alexandra; Latyshev, Alexey; Monnier, John D; Martinache, Frantz

    2015-01-01

    At present, the principal limitation on the resolution and contrast of astronomical imaging instruments comes from aberrations in the optical path, which may be imposed by the Earth's turbulent atmosphere or by variations in the alignment and shape of the telescope optics. These errors can be corrected physically, with active and adaptive optics, and in post-processing of the resulting image. A recently-developed adaptive optics post-processing technique, called kernel phase interferometry, uses linear combinations of phases that are self-calibrating with respect to small errors, with the goal of constructing observables that are robust against the residual optical aberrations in otherwise well-corrected imaging systems. Here we present a direct comparison between kernel phase and the more established competing techniques, aperture masking interferometry, point spread function (PSF) fitting and bispectral analysis. We resolve the alpha Ophiuchi binary system near periastron, using the Palomar 200-Inch Telesco...

  13. The Infrared Astronomical Satellite /IRAS/ Scientific Data Analysis System /SDAS/ sky flux subsystem

    Science.gov (United States)

    Stagner, J. R.; Girard, M. A.

    1980-01-01

    The sky flux subsystem of the Infrared Astronomical Satellite Scientific Data Analysis System is described. Its major output capabilities are (1) the all-sky lune maps (8-arcminute pixel size), (2) galactic plane maps (2-arcminute pixel size) and (3) regional maps of small areas such as extended sources greater than 1-degree in extent. The major processing functions are to (1) merge the CRDD and pointing data, (2) phase the detector streams, (3) compress the detector streams in the in-scan and cross-scan directions, and (4) extract data. Functional diagrams of the various capabilities of the subsystem are given. Although this device is inherently nonimaging, various calibrated and geometrically controlled imaging products are created, suitable for quantitative and qualitative scientific interpretation.

  14. A novel wireless light sensing device for planetary and astronomical observations

    Science.gov (United States)

    Durga Prasad, K.; Murty, S. V. S.; Chandrasekhar, T.

    2014-11-01

    A novel and versatile wireless light sensing device has been designed and tested for stellar and planetary photometric observations. The device weighing few 10 s of grams finds a number of potential applications in the fields of astronomy and in situ planetary exploration. A Wireless Sensor Network (WSN) using a number of these devices has been deployed to successfully carry out simultaneous photometric observations under different conditions viz. sunlight, twilight, moonlight etc. Observation of a star of known magnitude for flux calibration at low intensity has been carried out by coupling the device to a 1.2 m telescope which demonstrates its sensitivity. A WSN using these devices is further capable of spatio-temporal investigations of sky background intensities. Such a network can also be used to effectively monitor certain astronomical events (lunar eclipse, asteroid occultation etc.) simultaneously from several locations. The capability of the device, level of miniaturization and its versatility makes it a potential tool for many photometric applications.

  15. Supervised detection of anomalous light curves in massive astronomical catalogs

    Energy Technology Data Exchange (ETDEWEB)

    Nun, Isadora; Pichara, Karim [Computer Science Department, Pontificia Universidad Católica de Chile, Santiago (Chile); Protopapas, Pavlos [Institute for Applied Computational Science, Harvard University, Cambridge, MA (United States); Kim, Dae-Won [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

    2014-09-20

    The development of synoptic sky surveys has led to a massive amount of data for which resources needed for analysis are beyond human capabilities. In order to process this information and to extract all possible knowledge, machine learning techniques become necessary. Here we present a new methodology to automatically discover unknown variable objects in large astronomical catalogs. With the aim of taking full advantage of all information we have about known objects, our method is based on a supervised algorithm. In particular, we train a random forest classifier using known variability classes of objects and obtain votes for each of the objects in the training set. We then model this voting distribution with a Bayesian network and obtain the joint voting distribution among the training objects. Consequently, an unknown object is considered as an outlier insofar it has a low joint probability. By leaving out one of the classes on the training set, we perform a validity test and show that when the random forest classifier attempts to classify unknown light curves (the class left out), it votes with an unusual distribution among the classes. This rare voting is detected by the Bayesian network and expressed as a low joint probability. Our method is suitable for exploring massive data sets given that the training process is performed offline. We tested our algorithm on 20 million light curves from the MACHO catalog and generated a list of anomalous candidates. After analysis, we divided the candidates into two main classes of outliers: artifacts and intrinsic outliers. Artifacts were principally due to air mass variation, seasonal variation, bad calibration, or instrumental errors and were consequently removed from our outlier list and added to the training set. After retraining, we selected about 4000 objects, which we passed to a post-analysis stage by performing a cross-match with all publicly available catalogs. Within these candidates we identified certain known

  16. Calibration of the Herschel SPIRE Fourier Transform Spectrometer

    CERN Document Server

    Swinyard, B M; Hopwood, R; Valtchanov, I; Lu, N; Fulton, T; Benielli, D; Imhof, P; Marchili, N; Baluteau, J -P; Bendo, G J; Ferlet, M; Griffin, M J; Lim, T L; Makiwa, G; Naylor, D A; Orton, G S; Papageorgiou, A; Pearson, C P; Schulz, B; Sidher, S D; Spencer, L D; van der Wiel, M H D; Wu, R

    2014-01-01

    The Herschel SPIRE instrument consists of an imaging photometric camera and an imaging Fourier Transform Spectrometer (FTS), both operating over a frequency range of 450-1550 GHz. In this paper, we briefly review the FTS design, operation, and data reduction, and describe in detail the approach taken to relative calibration (removal of instrument signatures) and absolute calibration against standard astronomical sources. The calibration scheme assumes a spatially extended source and uses the Herschel telescope as primary calibrator. Conversion from extended to point-source calibration is carried out using observations of the planet Uranus. The model of the telescope emission is shown to be accurate to within 6% and repeatable to better than 0.06% and, by comparison with models of Mars and Neptune, the Uranus model is shown to be accurate to within 3%. Multiple observations of a number of point-like sources show that the repeatability of the calibration is better than 1%, if the effects of the satellite absolu...

  17. Prime Focus Spectrograph (PFS) for the Subaru Telescope: Overview, recent progress, and future perspectives

    CERN Document Server

    Tamura, Naoyuki; Shimono, Atsushi; Moritani, Yuki; Yabe, Kiyoto; Ishizuka, Yuki; Ueda, Akitoshi; Kamata, Yukiko; Aghazarian, Hrand; Arnouts, Stephane; Barban, Gabriel; Barkhouser, Robert H; Borges, Renato C; Braun, David F; Carr, Michael A; Chabaud, Pierre-Yves; Chang, Yin-Chang; Chen, Hsin-Yo; Chiba, Masashi; Chou, Richard C Y; Chu, You-Hua; Cohen, Judith G; de Almeida, Rodrigo P; de Oliveira, Antonio C; de Oliveira, Ligia S; Dekany, Richard G; Dohlen, Kjetil; Santos, Jesulino B dos; Santos, Leandro H dos; Ellis, Richard S; Fabricius, Maximilian; Ferrand, Didier; Ferreira, Decio; Golebiowski, Mirek; Greene, Jenny E; Gross, Johannes; Gunn, James E; Hammond, Randolph; Harding, Albert; Hart, Murdock; Heckman, Timothy M; Hirata, Christopher M; Ho, Paul; Hope, Stephen C; Hovland, Larry; Hsu, Shu-Fu; Hu, Yen-Shan; Huang, Ping-Jie; Jaquet, Marc; Jing, Yipeng; Karr, Jennifer; Kimura, Masahiko; King, Matthew E; Komatsu, Eiichiro; Brun, Vincent Le; Fevre, Olivier Le; Fur, Arnaud Le; Mignant, David Le; Ling, Hung-Hsu; Loomis, Craig P; Lupton, Robert H; Madec, Fabrice; Mao, Peter; Marrara, Lucas S; de Oliveira, Claudia Mendes; Minowa, Yosuke; Morantz, Chaz N; Murayama, Hitoshi; Murray, Graham J; Ohyama, Youichi; Orndorff, Joseph; Pascal, Sandrine; Pereira, Jefferson M; Reiley, Daniel J; Reinecke, Martin; Ritter, Andreas; Roberts, Mitsuko; Schwochert, Mark A; Seiffert, Michael D; Smee, Stephen A; Sodre, Laerte; Spergel, David N; Steinkraus, Aaron J; Strauss, Michael A; Surace, Christian; Suto, Yasushi; Suzuki, Nao; Swinbank, John; Tait, Philip J; Takada, Masahiro; Tamura, Tomonori; Tanaka, Yoko; Tresse, Laurence; Verducci, Orlando; Vibert, Didier; Vidal, Clement; Wang, Shiang-Yu; Wen, Chih-Yi; Yan, Chi-Hung; Yasuda, Naoki

    2016-01-01

    PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~1.6-2.7A. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project is now going into the construction phase aiming at undertaking system integration in 2017-2018 and subsequently carrying out engineering operations in 2018-2019. This article gives an overview of the instrument, current project status and future paths forward.

  18. Development of the MAMA Detectors for the Hubble Space Telescope Imaging Spectrograph

    Science.gov (United States)

    Timothy, J. Gethyn

    1997-01-01

    The development of the Multi-Anode Microchannel Array (MAMA) detector systems started in the early 1970's in order to produce multi-element detector arrays for use in spectrographs for solar studies from the Skylab-B mission. Development of the MAMA detectors for spectrographs on the Hubble Space Telescope (HST) began in the late 1970's, and reached its culmination with the successful installation of the Space Telescope Imaging Spectrograph (STIS) on the second HST servicing mission (STS-82 launched 11 February 1997). Under NASA Contract NAS5-29389 from December 1986 through June 1994 we supported the development of the MAMA detectors for STIS, including complementary sounding rocket and ground-based research programs. This final report describes the results of the MAMA detector development program for STIS.

  19. CHISL: The Combined High-resolution and Imaging Spectrograph for the LUVOIR Surveyor

    CERN Document Server

    France, Kevin; Hoadley, Keri

    2016-01-01

    NASA is currently carrying out science and technical studies to identify its next astronomy flagship mission, slated to begin development in the 2020s. It has become clear that a Large Ultraviolet/Optical/IR (LUVOIR) Surveyor mission (primary diameter 12 m, 1000 Ang - 2 micron spectroscopic bandpass) can carry out the largest number of NASA's exoplanet and astrophysics science goals over the coming decades. There are technical challenges for several aspects of the LUVOIR Surveyor concept, including component level technology readiness maturation and science instrument concepts for a broadly capable ultraviolet spectrograph. We present the scientific motivation for, and a preliminary design of, a multiplexed ultraviolet spectrograph to support both the exoplanet and astrophysics goals of the LUVOIR Surveyor mission concept, the Combined High-resolution and Imaging Spectrograph for the LUVOIR Surveyor (CHISL). CHISL includes a high-resolution (R 120,000; 1000 - 1700 Ang) point-source spectroscopy channel and a ...

  20. Astronomical Data Integration Beyond the Virtual Observatory

    Science.gov (United States)

    Lemson, G.; Laurino, O.

    2015-09-01

    "Data integration" generally refers to the process of combining data from different source data bases into a unified view. Much work has been devoted in this area by the International Virtual Observatory Alliance (IVOA), allowing users to discover and access databases through standard protocols. However, different archives present their data through their own schemas and users must still select, filter, and combine data for each archive individually. An important reason for this is that the creation of common data models that satisfy all sub-disciplines is fraught with difficulties. Furthermore it requires a substantial amount of work for data providers to present their data according to some standard representation. We will argue that existing standards allow us to build a data integration framework that works around these problems. The particular framework requires the implementation of the IVOA Table Access Protocol (TAP) only. It uses the newly developed VO data modelling language (VO-DML) specification, which allows one to define extensible object-oriented data models using a subset of UML concepts through a simple XML serialization language. A rich mapping language allows one to describe how instances of VO-DML data models are represented by the TAP service, bridging the possible mismatch between a local archive's schema and some agreed-upon representation of the astronomical domain. In this so called local-as-view approach to data integration, “mediators" use the mapping prescriptions to translate queries phrased in terms of the common schema to the underlying TAP service. This mapping language has a graphical representation, which we expose through a web based graphical “drag-and-drop-and-connect" interface. This service allows any user to map the holdings of any TAP service to the data model(s) of choice. The mappings are defined and stored outside of the data sources themselves, which allows the interface to be used in a kind of crowd-sourcing effort

  1. Astronomers Find World with Thick, Inhospitable Atmosphere and an Icy Heart

    Science.gov (United States)

    2009-12-01

    planets, they found that the observed radius exceeds the models' predictions: there is something more than the planet's solid surface blocking the star's light - a surrounding atmosphere, 200 km thick. "This atmosphere is much thicker than that of the Earth, so the high pressure and absence of light would rule out life as we know it," says Charbonneau, "but these conditions are still very interesting, as they could allow for some complex chemistry to take place." "Because the planet is too hot to have kept an atmosphere for long, GJ1214b represents the first opportunity to study a newly formed atmosphere enshrouding a world orbiting another star," adds team member Xavier Bonfils. "Because the planet is so close to us, it will be possible to study its atmosphere even with current facilities." The planet was first discovered as a transiting object within the MEarth project, which follows about 2000 low-mass stars to look for transits by exoplanets [4]. To confirm the planetary nature of GJ1214b and to obtain its mass (using the so-called Doppler method), the astronomers needed the full precision of the HARPS spectrograph, attached to ESO's 3.6-metre telescope at La Silla. An instrument with unrivalled stability and great precision, HARPS is the world's most successful hunter for small exoplanets. "This is the second super-Earth exoplanet for which the mass and radius could be obtained, allowing us to determine the density and to infer the inner structure," adds co-author Stephane Udry. "In both cases, data from HARPS was essential to characterise the planet." "The differences in composition between these two planets are relevant to the quest for habitable worlds," concludes Charbonneau. If super-Earth planets in general are surrounded by an atmosphere similar to that of GJ1214b, they may well be inhospitable to the development of life as we know it on our own planet. Notes [1] A super-Earth is defined as a planet between one and ten times the mass of the Earth. An exoplanet

  2. OLI Radiometric Calibration

    Science.gov (United States)

    Markham, Brian; Morfitt, Ron; Kvaran, Geir; Biggar, Stuart; Leisso, Nathan; Czapla-Myers, Jeff

    2011-01-01

    Goals: (1) Present an overview of the pre-launch radiance, reflectance & uniformity calibration of the Operational Land Imager (OLI) (1a) Transfer to orbit/heliostat (1b) Linearity (2) Discuss on-orbit plans for radiance, reflectance and uniformity calibration of the OLI

  3. Determination of forty trace impurity elements in uranium compounds using inductively coupled plasma atomic emission spectrography with end-on viewing of the ICP and a medium-size spectrograph

    International Nuclear Information System (INIS)

    A unified spectral analytical method is outlined which can determine up to 40 trace impurities elements in uranium compounds. This can be used to analyse nuclear fuels. The method uses a reversed-phase partition chromatographic technique to separate the impurities from the uranium matrix and end-on viewing of an inductively coupled plasma (ICP) using a medium-sized quartz spectrograph. The experimental method, calibration and results of recovery tests are given. The method uses a smaller sample (approx. 1/40) than the ASTM specified analytical procedure. (UK)

  4. The GERDA calibration system

    International Nuclear Information System (INIS)

    A system with three identical custom made units is used for the energy calibration of the GERDA Ge diodes. To perform a calibration the 228Th sources are lowered from the parking positions at the top of the cryostat. Their positions are measured by two independent modules. One, the incremental encoder, counts the holes in the perforated steel band holding the sources, the other measures the drive shaft's angular position even if not powered. The system can be controlled remotely by a Labview program. The calibration data is analyzed by an iterative calibration algorithm determining the calibration functions for different energy reconstruction algorithms and the resolution of several peaks in the 228Th spectrum is determined. A Monte Carlo simulation using the GERDA simulation software MAGE has been performed to determine the background induced by the sources in the parking positions.

  5. Sandia WIPP calibration traceability

    International Nuclear Information System (INIS)

    This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities

  6. AVES-IMCO: an adaptive optics visible spectrograph and imager/coronograph for NAOS

    Science.gov (United States)

    Beuzit, Jean-Luc; Lagrange, A.-M.; Mouillet, D.; Chauvin, G.; Stadler, E.; Charton, J.; Lacombe, F.; AVES-IMCO Team

    2001-05-01

    The NAOS adaptive optics system will very soon provide diffraction-limited images on the VLT, down to the visible wavelengths (0.020 arcseconds at 0.83 micron for instance). At the moment, the only instrument dedicated to NAOS is the CONICA spectro-imager, operating in the near-infrared from 1 to 5 microns. We are now proposing to ESO, in collaboration with an Italian group, the development of a visible spectrograph/imager/coronograph, AVES-IMCO (Adaptive Optics Visual Echelle Spectrograph and IMager/COronograph). We present here the general concept of the new instrument as well as its expected performances in the different modes.

  7. An educational spectrograph using a digital camera as a training aid for physics students

    International Nuclear Information System (INIS)

    The paper considers the assembly, handling and performance of an educational spectrograph/spectrophotometer which uses an inexpensive mirrorless digital camera with a removable lens as the array detector. Such a spectrograph is shown to be a good training aid for physics students because (1) the large sensor area permits the use of bigger optical components; (2) the spectrum which forms on the sensor is immediately visible in its original colours on the LCD screen; (3) the sensor is sufficiently sensitive to allow the measurement of all basic types of spectroscopic phenomena (including fluorescence); and (4) a relatively small amount of time is required for the preparation of such a setup. (paper)

  8. Spectrographic Determination of Trace Constituents in Rare Earths; Determinacion espectrografica de impurezas en tierras raras

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.; Alvarez, F.

    1962-07-01

    A spectrographic method was developed for the determination of 18 trace elements in lanthanum, cerium, praseodimium, neodimium and samarium compounds. The concentrations of the impurities cover the range of 0,5 to 500 ppm. Most of these impurities are determined by the carrier distillation method. Several more refractory elements have been determined by total burning of the sample with a direct current arc or by the conduction briquet excitation technique with a high voltage condensed spark. The work has been carried out with a Hilger Automatic Large Quartz Spectrograph. (Author) 5 refs.

  9. SCR flare of 16 February 1984 as recorded by the Sayan spectrograph

    International Nuclear Information System (INIS)

    The Sayan cosmic ray (CR) spectrograph recorded an SCR flare that occurred on 16 February 1984. Data from both 1-hour and 110-minute duration measurements in 10 channels with different energy sensitivity (of neutron monitors HM-64 located at different depths in the atmosphere, and of a neutron, multiple neutron and rigid mu meson component lead-less detector) is presented. The parameters of the SCR variation spectrum are evaluated and it is shown that the recording of multiple neutrons at the same geographic point and at the same level in the atmosphere provides information similar to that from a spectrographic complex of instruments

  10. Spectrographic determination of some non-rare-earth trace elements in allanite

    International Nuclear Information System (INIS)

    An emission spectrographic method for estimating traces of Be, Pb, Sn, Ga, Mn, Nb, Ti, Mo, V, Zr, Cu and Sc in allanite, a complex rare earth mineral, is described. Using 3.4 m Jarrell-Ash grating spectrograph, the spectra of standards and samples mixed with specpure graphite-internal standard mixture, are photographed in the spectral region 2275-3525 A in first order. Silicon and palladium are used as internal standard elements, for the estimation of these elements. Most of the trace elements are determined in the range of their natural abundance in allanites. The mean standard deviation of the method is found to be +- 14%. (author)

  11. The use of an elliptical analyzer spectrograph for characterization of LPP X-ray emission

    International Nuclear Information System (INIS)

    Due to its favorable characteristics briefly surveyed in the paper, an elliptically bent crystal was chosen for an X-ray spectrograph applied to a laser-produced plasma. By using a ray-tracing optimization procedure, a simple and compact instrument was designed with a crystal of mica bent over the surface of two elliptically shaped mounting blocks. The instrument was successfully tested in interaction experiments at the iodine photodissociation laser system Perun. Some results of these experiments are presented. It is demonstrated that the spectrograph may be used for high resolution X-ray spectroscopy in a relatively broad energy range. (J.U.) 4 figs., 5 refs

  12. On-sky tests of sky-subtraction methods for fiber-fed spectrographs

    CERN Document Server

    Rodrigues, Myriam; Hammer, Francois; Royer, Frederic; Evans, C J; Puech, Mathieu; Flores, Hector; Guinouard, Isabelle; Causi, Gianluca Li; Disseau, Karen; Yang, Yanbin

    2016-01-01

    We present preliminary results on on-sky test of sky subtraction methods for fiber-fed spectrograph. Using dedicated observation with FLAMES/VLT in I-band, we have tested the accuracy of the sky subtraction for 4 sky subtraction methods: mean sky, closest sky, dual stare and cross-beam switching. The cross beam-switching and dual stare method reach accuracy and precision of the sky subtraction under 1%. In contrast to the commonly held view in the literature, this result points out that fiber-fed spectrographs are adapted for the observations of faint targets.

  13. The SCR flare of 16 February 1984 as recorded by the Sayan spectrograph

    Science.gov (United States)

    Koslov, S. A.; Pakhomov, N. I.; Shapovalova, L. A.; Yanchukovsky, A. L.

    1985-01-01

    The Sayan cosmic ray (CR) spectrograph recorded an SCR flare that occurred on 16 February 1984. Data from both 1-hour and 110-minute duration measurements in 10 channels with different energy sensitivity (of neutron monitors HM-64 located at different depths in the atmosphere, and of a neutron, multiple neutron and rigid mumeson component lead-less detector) is presented. The parameters of the SCR variation spectrum are evaluated and it is shown that the recording of multiple neutrons at the same geographic point and at the same level in the atmosphere provides information similar to that from a spectrographic complex of instruments.

  14. Long-publishing astronomers, or the problem of classification

    Science.gov (United States)

    Tenn, Joseph S.

    2012-03-01

    In response to several discussions among astronomers and historians of astronomy, I started out to prepare a paper on long-publishing astronomers-those who published for 70, 75, or even 80 years. However, I soon ran into a number of questions of classification, and that turned out to be at least as interesting. How do we decide on classifications? Every time we choose classes, such as asteroids, planets and stars, we run into objects that seem to be in between. In the present case a number of questions arise: Who is an astronomer? Several of those with the longest publication runs started out as physicists, published for years in that subject only, and later took up astrophysics, eventually publishing a few papers in astronomy journals. What is a publication? Should we count publications in physics, chemistry, or mathematics? What about philosophy of science or history of science? What about the elderly retired astronomer presenting a memoir of his or her own work? Abstracts of oral presentations? Monographs? Textbooks? Book reviews? Obituaries? Then there is the problem of posthumous publications. Probably most would include papers in the pipeline when the astronomer dies, but what about the case where the coauthor finally publishes the paper as much as twenty-two years after the death of the person of interest? I eventually decided to make two lists, one which would include most of the above, and one restricted to papers that make contributions to physical science. Note that I do not say 'refereed', as that presents its own problems, especially when applied to periods before the twentieth century. I present a list of astronomers who have published for periods of 68 to 80 years and discuss the problems of defining such terms as astronomer and publication.

  15. A record of astronomically forced climate change in a late Ordovician (Sandbian) deep marine sequence, Ordos Basin, North China

    Science.gov (United States)

    Fang, Qiang; Wu, Huaichun; Hinnov, Linda A.; Wang, Xunlian; Yang, Tianshui; Li, Haiyan; Zhang, Shihong

    2016-07-01

    The late Ordovician Pingliang Formation on the southwestern margin of the Ordos Basin, North China, consists of rhythmic alternations of shale, limestone, and siliceous beds. To explore the possible astronomical forcing preserved in this lithological record, continuous lithological rank and magnetic susceptibility (MS) stratigraphic series were obtained from a ~ 34 m thick section of the Pingliang Formation at Guanzhuang. Power spectral analysis of the MS and rank series reveal 85.5 cm to 124 cm, 23 cm to 38 cm, and 15 cm to 27 cm thick sedimentary cycles that in ratio match that of late Ordovician short eccentricity, obliquity and precession astronomical cycles. The power spectrum of the MS time series, calibrated to interpreted short orbital eccentricity cycles, aligns with spectral peaks to astronomical parameters, including 95 kyr short orbital eccentricity, 35.3 kyr and 30.6 kyr obliquity, and 19.6 kyr and 16.3 kyr precession cycles. The 15 cm to 27 cm thick limestone-shale couplets mainly represent precession cycles, and siliceous bed deposition may be related to both precession and obliquity forcing. We propose that precession-forced sea-level fluctuations mainly controlled production of lime mud in a shallow marine environment, and transport to the basin. Precession and obliquity controlled biogenic silica productivity, and temperature-dependent preservation of silica may have been influenced by obliquity forcing.

  16. Segment Based Camera Calibration

    Institute of Scientific and Technical Information of China (English)

    马颂德; 魏国庆; 等

    1993-01-01

    The basic idea of calibrating a camera system in previous approaches is to determine camera parmeters by using a set of known 3D points as calibration reference.In this paper,we present a method of camera calibration in whih camera parameters are determined by a set of 3D lines.A set of constraints is derived on camea parameters in terms of perspective line mapping.Form these constraints,the same perspective transformation matrix as that for point mapping can be computed linearly.The minimum number of calibration lines is 6.This result generalizes that of Liu,Huang and Faugeras[12] for camera location determination in which at least 8 line correspondences are required for linear computation of camera location.Since line segments in an image can be located easily and more accurately than points,the use of lines as calibration reference tends to ease the computation in inage preprocessing and to improve calibration accuracy.Experimental results on the calibration along with stereo reconstruction are reported.

  17. How Astronomers View Education and Public Outreach: An Exploratory Study

    Science.gov (United States)

    Dang, L.; Russo, P.

    2015-09-01

    Over the past few years there have been a number of studies exploring the development of an interest in science and scientists' views on public outreach. Yet, to date, there has been no global study regarding astronomers' views on these matters. Through the completion of our survey of 155 professional astronomers online and in person during the 28th International Astronomical Union General Assembly in 2012, we explore how these individuals developed an interest in astronomy, the part outreach played in this and their views on the time constraints and budget restrictions associated with public outreach activities. We find that astronomers develop an interest in astronomy between the ages of four and six, but that the decision to undertake a career in astronomy often comes during late adolescence. We also discuss the claim that education and public outreach is regarded as an optional task rather than a scientist's duty. Our study reveals that many astronomers are of the opinion that a larger percentage of their research time should be invested in outreach activities, calling for a change in grant policies.

  18. The first massive astronomical observation event in Mexico City

    Science.gov (United States)

    Espinosa, Mariana; Hernandez, Xavier

    2011-06-01

    On the night of the 20th of February 2008 there was a total eclipse of the moon visible from Mexico City, with a total duration from 19:42 hrs to 23:09 hrs. At the Instituto de Astronomía, UNAM, we took this opportunity to organise a massive astronomical party on the central plaza of the city, the Zocalo. Over a period of about 6 hrs. we set up a huge astro-party, with free use of over 100 telescopes, where we estimate over 40,000 persons looked through an astronomical telescope at the moon and Saturn, most for the first time in their lives. Numerous stands including a children's games, an Astronomy conference room, and the free distribution of Astronomical material were organised. Here we describe some of the issues associated with the planning and implementation of the event. Coordination issues were complex, involving interaction with divers and numerous authorities, city, national, police, traffic, medical assistance in readiness, aide from other universities, and amateur astronomical societies, which supplied most of the telescopes. An extensive publicity campaign was launched with several weeks of anticipation, and although we had no way of estimating the public response, we were ready with over 800 volunteers at the Zócalo on the 20th of February. The public response was massive and overwhelmingly positive, thousands swarmed the square in a completely peaceful and well organised interaction between Astronomy and society at large, over many complementary levels

  19. Astronomical Flux Standards: Getting to 1%

    Science.gov (United States)

    Deustua, Susana; Cikota, Aleksandar; Hines, Dean C.; Bohlin, Ralph; Gordon, Karl

    2015-08-01

    The objective for pursuing sub-1% absolute photometric accuracies, and, establishing the Absolute Physical Flux of ever fainter standard stars, is motivated by the requirements of Dark Energy science with JWST and other facilities. Even with the best data available, the current determination of absolute physical flux is is plagued by the reliance on the Vega photometric system, which is known to be problematic primarily due to the fact that Vega is a pole-on rapid rotator with an infrared excess from its circumstellar disk! which makes it difficult to model. Vega is also far too bright for large aperture telescopes. In an effort to remedy these difficulties, teams from e.g. the National Institute of Standards (NIST), University of New Mexico, Johns Hopkins University and STScI have begun to develop a catalog of stars that have spectral energy distributions that are tied directly to SI (diode) standards with very precisely determined physical characteristics. A key element in this pursuit has been the efforts at STScI to measure the spectra of many of these objects with STIS. We discuss our program to extend this effort into the near-IR which is crucial to reliably extend the SEDs to longer wavelengths, including the mid IR. We describe results from our effort towards 1% absolute color calibration in the UV-VIS-NIR with Hubble Space Telescope's WFC3/IR observations of 15 carefully selected stars with the immediate objective of establishing their absolute flux.

  20. Ka-Band Monopulse Antenna Pointing Calibration Using Wideband Radio Sources

    Science.gov (United States)

    Buu, C.; Calvo, J.; Cheng, T.-H.; Vazquez, M.

    2010-08-01

    A new method of performing a system end-to-end monopulse antenna calibration using widely available wideband astronomical radio sources is presented as an alternative to the current method of using a spacecraft signal. Current monopulse calibration requires a spacecraft carrier signal to measure amplitude and phase differences in the monopulse feed and low-noise amplifiers (LNAs). The alternative method presented here will allow the ground station to perform monopulse calibrations during maintenance periods instead of spacecraft track time, and provide an end-to-end system check-out capability without requiring a spacecraft signal. In this article, we give an overview of the current calibration approach, describe a new method for calibrating with radio sources, and present results from field testing of this new method.