WorldWideScience

Sample records for angular resolution astronomy

  1. X-ray interferometry with transmissive beam combiners for ultra-high angular resolution astronomy

    OpenAIRE

    Skinner, G. K.; Krizmanic, J. F.

    2009-01-01

    Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event horizon of a super-massive black hole at the center of an active galaxy, can be achieved if beams from parts of the incoming wavefront separated by 100s of meters can be stably and accurately brought together at small angles. One way of achieving this is by us...

  2. Astronomy at high angular resolution a compendium of techniques in the visible and near-infrared

    CERN Document Server

    Hussain, Gaitee; Berger, Jean-Philippe; Schmidtobreick, Linda

    2016-01-01

    This book offers an essential compendium of astronomical high-resolution techniques. Recent years have seen considerable developments in such techniques, which are critical to advances in many areas of astronomy. As reflected in the book, these techniques can be divided into direct methods, interferometry, and reconstruction methods, and can be applied to a huge variety of astrophysical systems, ranging from planets, single stars and binaries to active galactic nuclei, providing angular resolution in the micro- to tens of milliarcsecond scales. Written by experts in their fields, the chapters cover adaptive optics, aperture masking imaging, spectra disentangling, interferometry, lucky imaging, Roche tomography, imaging with interferometry, interferometry of AGN, AGN reverberation mapping, Doppler- and magnetic imaging of stellar surfaces, Doppler tomography, eclipse mapping, Stokes imaging, and stellar tomography. This book is intended to enable a next generation of astronomers to apply high-resolution techni...

  3. The future of high angular resolution x-ray optics for astronomy (Conference Presentation)

    Science.gov (United States)

    Gorenstein, Paul

    2017-05-01

    Beginning with the Einstein Observatory in 1978, continuing with ROSAT in the 1990's and currently the Chandra X-Ray Observatory, high angular resolution focusing telescopes have been the premier X-ray astronomy instruments of their time. However, as they have acquired larger area and improved angular resolution they have become increasingly massive and expensive. The successor to Chandra planned for the late 2020's currently named "Lynx" will rely on active optics to allow the use of much lower mass segmented mirrors with the goal of gaining an order of magnitude larger area than Chandra with a lower ratio of mass to effective area and perhaps slightly better angular resolution than Chandra's 0.5 arc second half power diameter and/or over a somewhat larger field. The goals for Lynx are probably at the limit of what is possible with grazing incidence X-ray optics. Success in the development of higher angular resolution, lower mass telescopes will come at the expense of effective area. A diffractive-refractive pair consisting of a Fresnel zone plate and a diffractive lens that transmits rather than reflects X-rays is capable in theory of achieving mili arc second resolution with a much lower ratio of mass to effective area than the grazing incidence reflective Wolter optics. However, the focal lengths of this system are thousands of kilometers necessitating formation flying between one spacecraft hosting the optics and another hosting the detectors, most likely in a Sun-Earth L2 orbit. The trajectory of one of the two spacecraft can be in a true orbit but the other must be powered by an ion engine to maintain the alignment. The growing interest in deep space astronaut operations may allow the ion engines to be replaced when depleted.

  4. Rectilinear Graphs and Angular Resolution

    NARCIS (Netherlands)

    Bodlaender, H.L.; Tel, G.

    2003-01-01

    In this note we show that a planar graph with angular resolution at least π/2 can be drawn with all angles an integer multiple of π/2, that is, in a rectilinear manner. Moreover, we show that for d ≠ 4, d › 2, having an angular resolution of 2π/d does not imply that the graph can be drawn with all

  5. Fabricating High Resolution Mirrors for Hand X-Ray Astronomy

    Science.gov (United States)

    Speegle, Chet O.; Ramsey, Brian D.; Engelhaupt, Darell; Six, N. Frank (Technical Monitor)

    2001-01-01

    We describe the fabrication process for producing high-resolution conical mirrors for hard x-ray astronomy. When flown aboard stratospheric balloons, these high-resolution reflective mirrors focus hard x-rays (10-70 keV) emitted from cosmic sources such as supernovae, neutron stars, and quasars onto imaging focal plane detectors. Focused hard x-ray images allow scientists to determine the elemental compositions, temperatures, magnetic fields, velocities, and gravitational fields of these celestial bodies. The fabrication process involves generating super-polished mandrels, mandrel metrology, mirror shell nickel electroforming, and mirror testing. Each mandrel is a cylinder consisting of two conical segments; each segment is approximately 305-mm long. Through precision grinding these mandrels before super polishing, we have achieved 30 arc seconds, half power diameter replicated mirrors. During a May 2001 high atmosphere balloon flight, these mirrors focused high energy x-rays from three different celestial sources. However, we seek to improve the angular resolutions of future mirror shells by a factor of two. To achieve this goal, we have begun single point diamond turning the mandrels before super polishing. This has allowed greater precision tolerances on mandrel surface roughness and axial figure errors before super polishing. Surface roughnesses before polishing have been reduced from approximately 60 nm to approximately 15 nm. The peak to valley axial figure profile errors have been reduced from approximately 1.0 micrometers to approximately 0.4 micrometers. We are currently in Phase 2 of the HERO (high energy replicated optics) program which entails the production of sixteen 6-m-focal-length mirror modules, each containing a nested array of 15 mirror shells of diameters ranging from 50-mm to 94-mm. This flight is slated for the fall of 2003.

  6. Microbeam High Angular Resolution Diffraction Applied to Optoelectronic Devices

    International Nuclear Information System (INIS)

    Kazimirov, A.; Bilderback, D. H.; Sirenko, A. A.; Cai, Z.-H.; Lai, B.

    2007-01-01

    Collimating perfect crystal optics in a combination with the X-ray focusing optics has been applied to perform high angular resolution microbeam diffraction and scattering experiments on micron-size optoelectronic devices produced by modern semiconductor technology. At CHESS, we used capillary optics and perfect Si/Ge crystal(s) arrangement to perform X-ray standing waves, high angular-resolution diffraction and high resolution reciprocal space mapping analysis. At the APS, 2ID-D microscope beamline, we employed a phase zone plate producing a beam with the size of 240 nm in the horizontal plane and 350 nm in the vertical (diffraction) plane and a perfect Si (004) analyzer crystal to perform diffraction analysis of selectively grown InGaAsP and InGaAlAs-based waveguides with arc sec angular resolution

  7. Classical Angular Momentum of Light: A Paradox and its Resolution

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 10. Classical Angular Momentum of Light: A Paradox and its Resolution. K Vijay Kumar N Kumar. Classroom Volume 8 Issue 10 October 2003 pp 69-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Accessing High Spatial Resolution in Astronomy Using Interference Methods

    Science.gov (United States)

    Carbonel, Cyril; Grasset, Sébastien; Maysonnave, Jean

    2018-01-01

    In astronomy, methods such as direct imaging or interferometry-based techniques (Michelson stellar interferometry for example) are used for observations. A particular advantage of interferometry is that it permits greater spatial resolution compared to direct imaging with a single telescope, which is limited by diffraction owing to the aperture of…

  9. Statistical Angular Resolution Limit for Ultrawideband MIMO Noise Radar

    Directory of Open Access Journals (Sweden)

    Xiaoli Zhou

    2015-01-01

    Full Text Available The two-dimensional angular resolution limit (ARL of elevation and azimuth for MIMO radar with ultrawideband (UWB noise waveforms is investigated using statistical resolution theory. First, the signal model of monostatic UWB MIMO noise radar is established in a 3D reference frame. Then, the statistical angular resolution limits (SARLs of two closely spaced targets are derived using the detection-theoretic and estimation-theoretic approaches, respectively. The detection-theoretic approach is based on the generalized likelihood ratio test (GLRT with given probabilities of false alarm and detection, while the estimation-theoretic approach is based on Smith’s criterion which involves the Cramér-Rao lower bound (CRLB. Furthermore, the relationship between the two approaches is presented, and the factors affecting the SARL, that is, detection parameters, transmit waveforms, array geometry, signal-to-noise ratio (SNR, and parameters of target (i.e., radar cross section (RCS and direction, are analyzed. Compared with the conventional radar resolution theory defined by the ambiguity function, the SARL reflects the practical resolution ability of radar and can provide an optimization criterion for radar system design.

  10. Compact and high-resolution optical orbital angular momentum sorter

    Directory of Open Access Journals (Sweden)

    Chenhao Wan

    2017-03-01

    Full Text Available A compact and high-resolution optical orbital angular momentum (OAM sorter is proposed and demonstrated. The sorter comprises a quadratic fan-out mapper and a dual-phase corrector positioned in the pupil plane and the Fourier plane, respectively. The optical system is greatly simplified compared to previous demonstrations of OAM sorting, and the performance in resolution and efficiency is maintained. A folded configuration is set up using a single reflective spatial light modulator (SLM to demonstrate the validity of the scheme. The two phase elements are implemented on the left and right halves of the SLM and connected by a right-angle prism. Experimental results demonstrate the high resolution of the compact OAM sorter, and the current limit in efficiency can be overcome by replacing with transmissive SLMs and removing the beam splitters. This novel scheme paves the way for the miniaturization and integration of high-resolution OAM sorters.

  11. Space active optics sensing and control for earth observation at high angular resolution

    Science.gov (United States)

    Escolle, C.; Michau, V.; Ferrari, M.; Fusco, T.; Hugot, E.; Bret-Dibat, T.

    2017-11-01

    Discoveries in astronomy and earth science lie on the capabilities of the space observatories to see fainter objects and smaller details. This need of high collecting power and high angular resolution implies instruments with large primary mirrors. However, a simple scaling of existing space telescopes leads to bigger optical elements and structure that exceed the allocated volume and launch mass capability of medium size launchers. Due to volume, weight and cost constraints on satellites, the next generation of large telescopes must combine innovative and compact optical concepts using lightweight primary mirrors and structures. Furthermore the lightweighting of primary mirrors and structures reduce their stiffness and make them more deformable under static and dynamic load. Also, the compactness needed implies primary mirrors with low focal ratio and a small distance between primary and secondary mirrors. This leads to an optical train more sensitive to misalignment.

  12. High angular resolution diffusion imaging with stimulated echoes

    DEFF Research Database (Denmark)

    Lundell, Henrik; Alexander, Daniel C; Dyrby, Tim B

    2014-01-01

    Stimulated echo acquisition mode (STEAM) diffusion MRI can be advantageous over pulsed-gradient spin-echo (PGSE) for diffusion times that are long compared with T2 . It therefore has potential for biomedical diffusion imaging applications at 7T and above where T2 is short. However, gradient pulses...... angular resolution diffusion imaging (HARDI) data were acquired with and without the proposed compensation. The data were processed to derive standard diffusion tensor imaging (DTI) maps, which highlight the need for the compensation. Ignoring the other gradient pulses, a bias in DTI parameters from STEAM...

  13. Accessing High Spatial Resolution in Astronomy Using Interference Methods

    Science.gov (United States)

    Carbonel, Cyril; Grasset, Sébastien; Maysonnave, Jean

    2018-04-01

    In astronomy, methods such as direct imaging or interferometry-based techniques (Michelson stellar interferometry for example) are used for observations. A particular advantage of interferometry is that it permits greater spatial resolution compared to direct imaging with a single telescope, which is limited by diffraction owing to the aperture of the instrument as shown by Rueckner et al. in a lecture demonstration. The focus of this paper, addressed to teachers and/or students in high schools and universities, is to easily underline both an application of interferometry in astronomy and stress its interest for resolution. To this end very simple optical experiments are presented to explain all the concepts. We show how an interference pattern resulting from the combined signals of two telescopes allows us to measure the distance between two stars with a resolution beyond the diffraction limit. Finally this work emphasizes the breathtaking resolution obtained in state-of-the-art instruments such as the VLTi (Very Large Telescope interferometer).

  14. Optical Design of the Submillimeter High Angular Resolution Camera (SHARC)

    Science.gov (United States)

    Hunter, T. R.; Benford, D. J.; Serabyn, E.

    1996-11-01

    The optical and mechanical design and performance of the Submillimeter High Angular Resolution Camera (SHARC) is described. The camera currently operates with a monolithic 24-pixel linear bolometer array in the 350 and 450 micron atmospheric windows at the Caltech Submillimeter Observatory (CSO). The design extends the techniques of geometric optics employed in optical and near-infrared cameras to submillimeter wavelengths. Using an off-axis ellipsoidal mirror and cold stops, excellent imaging (Strehl ratio > 0.95) is achieved across a 2' by 2' focal plane field even with secondary throws of up to 4'. The camera's symmetric mechanical assembly provides fixed, machined alignment of the optical elements. We demonstrate the imaging capabilities of the system with 350 micron observations of a point source at the telescope. The optical design can easily accommodate future planned upgrades to two-dimensional bolometer arrays. (SECTION: Astronomical Instrumentation)

  15. Multiframe super resolution reconstruction method based on light field angular images

    Science.gov (United States)

    Zhou, Shubo; Yuan, Yan; Su, Lijuan; Ding, Xiaomin; Wang, Jichao

    2017-12-01

    The plenoptic camera can directly obtain 4-dimensional light field information from a 2-dimensional sensor. However, based on the sampling theorem, the spatial resolution is greatly limited by the microlenses. In this paper, we present a method of reconstructing high-resolution images from the angular images. First, the ray tracing method is used to model the telecentric-based light field imaging process. Then, we analyze the subpixel shifts between the angular images extracted from the defocused light field data and the blur in the angular images. According to the analysis above, we construct the observation model from the ideal high-resolution image to the angular images. Applying the regularized super resolution method, we can obtain the super resolution result with a magnification ratio of 8. The results demonstrate the effectiveness of the proposed observation model.

  16. Frequency and Angular Resolution for Measuring, Presenting and Predicting Loudspeaker Polar Data

    DEFF Research Database (Denmark)

    Staffeldt, Henrik; Seidel, Felicity

    1996-01-01

    are needed to represent and predict the sound fields from single and multiple sound sources more accurately.The relationship between measurement resolution and the accuracy of presented or predicted polar and frequency responses from single or arrayed loudspeakers is described. Plane and spherical polar data...... and angular resolution for measuring, presenting and predicting loudspeaker polar data.......The spherical polar loudspeaker data available today are usually measured with such a coarse resolution that only rough estimates of the performance of sound systems can be predicted by applying these data. Complex, spherical polar data with higher angular and frequency resolutions than used today...

  17. High Resolution Adjustable Mirror Control for X-ray Astronomy

    Science.gov (United States)

    Trolier-McKinstry, Susan

    We propose to build and test thin film transistor control circuitry for a new highresolution adjustable X-ray mirror technology. This control circuitry will greatly simplify the wiring scheme to address individual actuator cells. The result will be a transformative improvement for the X-ray Surveyor mission concept: mathematical models, which fit the experimental data quite well, indicate that 0.5 arcsecond imaging is feasible through this technique utilizing thin slumped glass substrates with uncorrected angular resolution of order 5-10 arcseconds. In order to correct for figures errors in a telescope with several square meters of collecting area, millions of actuator cells must be set and held at specific voltages. It is clearly not feasible to do this via millions of wires, each one connected to an actuator. Instead, we propose to develop and test thin-film technology that operates on the same principle as megapixel computer screens. We will develop the technologies needed to build thin film piezoelectric actuators, controlled by thin film ZnO transistors, on flexible polyimide films, and to connect those films to the back surfaces of X-ray mirrors on thin glass substrates without deforming the surface. These technologies represent a promising avenue of the development of mirrors for the X-Ray Surveyor mission concept. Such a telescope will make possible detailed studies of a wide variety of astrophysical sources. One example is the Warm-Hot Intergalactic Medium (WHIM), which is thought to account for a large fraction of the normal matter in the universe but which has not been detected unambiguously to date. Another is the growth of supermassive black holes in the early universe. This proposal supports NASA's goals of technical advancement of technologies suitable for future missions, and training of graduate students.

  18. The High Angular Resolution Multiplicity of Massive Stars

    Science.gov (United States)

    2009-02-01

    because of the very short timescale of formation. Instead, the initial angular momentum of the natal cloud may end up (through a variety of processes...0.132 1.2 1 3 03272+0944 HDS 433 HD 21364 2005.8616 53.8 0.224 3.8 2 −6.9 −0.012 Romero (2007) 03284+6015 A 980 AB HD 21203 2007.6022 337.9 0.364 1.6... Romero , F. M. R. 2006a, IAU Comm. 26 Inf. Circ., 158 Romero , F. M. R. 2006b, IAU Comm. 26 Inf. Circ., 160 Romero , F. M. R. 2006c, IAU Comm. 26 Inf

  19. Perspective for optical high-angular resolution follow-up studies of X-raying AGNs

    OpenAIRE

    Labadie, Lucas; Zuther, Jens; Eckart, Andreas; Staley, Tim; Mackay, Craig; Rebolo, Rafael

    2014-01-01

    We explore the scientific potential of next-generation high-angular resolution optical imager to study the AGN/Host connection. The availability of a significant number of X-raying AGN with natural guide stars, allowing for adaptive optics at optical wavelengths, offers an interesting perspective to complement high-resolution work currently done in the near-infrared.

  20. Development of the super high angular resolution principle for X-ray imaging

    International Nuclear Information System (INIS)

    Zhang Chen; Zhang Shuangnan

    2011-01-01

    Development of the Super High Angular Resolution Principle (SHARP) for coded-mask X-ray imaging is presented. We prove that SHARP can be considered as a generalized coded mask imaging method with a coding pattern comprised of diffraction-interference fringes in the mask pattern. The angular resolution of SHARP can be improved by detecting the fringes more precisely than the mask's element size, i.e. by using a detector with a pixel size smaller than the mask's element size. The proposed mission SHARP-X for solar X-ray observations is also briefly discussed. (research papers)

  1. Astronomy

    CERN Document Server

    Seymour, Percy

    2014-01-01

    With a blend of exciting discoveries and important scientific theory,this innovative and readable introduction to astronomy is ideal for anyone who wants to understand what we know about the universe,and how we know it. Each chapter starts with details of a method of jow astronomers over time have observed the world,and then uses this as a springboard to discuss what they discovered,and why this was important for understanding the cosmos. The last chapter,on dark matter,also focuses on the many things we don''t yet know - reminding us that astronomy,like this book,is a fast-paced and fascinati

  2. A 3D CZT high resolution detector for x- and gamma-ray astronomy

    DEFF Research Database (Denmark)

    Kuvvetli, Irfan; Budtz-Jørgensen, Carl; Zappettini, A.

    2014-01-01

    At DTU Space we have developed a high resolution three dimensional (3D) position sensitive CZT detector for high energy astronomy. The design of the 3D CZT detector is based on the CZT Drift Strip detector principle. The position determination perpendicular to the anode strips is performed using...

  3. Finsler geometry on higher order tensor fields and applications to high angular resolution diffusion imaging.

    NARCIS (Netherlands)

    Astola, L.; Florack, L.

    2011-01-01

    We study 3D-multidirectional images, using Finsler geometry. The application considered here is in medical image analysis, specifically in High Angular Resolution Diffusion Imaging (HARDI) (Tuch et al. in Magn. Reson. Med. 48(6):1358–1372, 2004) of the brain. The goal is to reveal the architecture

  4. A hard x-ray spectrometer for high angular resolution observations of cosmic sources

    International Nuclear Information System (INIS)

    Hailey, C.J.; Ziock, K.P.; Harrison, F.; Kahn, S.M.; Liedahl, D.; Lubin, P.M.; Seiffert, M.

    1988-01-01

    LAXRIS (large area x-ray imaging spectrometer) is an experimental, balloon-borne, hard x-ray telescope that consists of a coaligned array of x-ray imaging spectrometer modules capable of obtaining high angular resolution (1--3 arcminutes) with moderate energy resolution in the 20- to 300-keV region. Each spectrometer module consists of a CsI(Na) crystal coupled to a position-sensitive phototube with a crossed-wire, resistive readout. Imaging is provided by a coded aperture mask with a 4-m focal length. The high angular resolution is coupled with rather large area (/approximately/800 cm 2 ) to provide good sensitivity. Results are presented on performance and overall design. Sensitivity estimates are derived from a Monte-Carlo code developed to model the LAXRIS response to background encountered at balloon altitudes. We discuss a variety of observations made feasible by high angular resolution. For instance, spatially resolving the nonthermal x-ray emission from clusters of galaxies is suggested as an ideal program for LAXRIS. 15 refs., 5 figs

  5. Synchrotron high angular resolution microdiffraction analysis of selective area grown optoelectronic waveguide arrays

    International Nuclear Information System (INIS)

    Kazimirov, A; Sirenko, A A; Bilderback, D H; Cai, Z-H; Lai, B; Huang, R; Ougazzaden, A

    2006-01-01

    A synchrotron microbeam high-angular resolution diffraction setup based on a phase zone plate and a perfect Si(004) analyzer crystal was introduced to generate an x-ray microbeam with a lateral size of 0.24 μm and an angular resolution of 2 arcsec. The microbeam high angular resolution x-ray diffraction was applied to study InGaAlAs-based multiple quantum well (MQW) ridge-waveguide arrays produced by metal-organic vapour-phase epitaxy in a selective area growth regime with a central waveguide width varying from 1.6 to 60 μm. The analysis of the period T and the strain S in MQW ridge structures determined from the high-resolution diffraction data is presented. It was found that the MQW period is uniform across the ridge within the error bar of ΔT = ± 0.25 nm. Within the waveguide array, the MQW period and strain can be adequately described by a gas-phase diffusion model

  6. Dust Continuum Imaging with the Submillimeter High Angular Resolution Camera (SHARC)

    Science.gov (United States)

    Lis, D. C.

    The advent of sensitive bolometer array receivers operating at millimeter and submillimeter wavelengths has allowed large-scale imaging of the distribution of cold dust in star-forming regions. Owing to their high sensitivity and angular resolution, these observations reveal a wealth of structure, including a number of protostellar sources in various evolutionary stages. The Submillimeter High-Angular Resolution Camera (SHARC) is one of the facility instruments at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii. It employs a 20-pixel monolithic silicon bolometer array operating at 300 mK and is used for diffraction limited broad-band continuum imaging at the wavelengths of 350 microns and 450 microns. I present a summary of the results of recent studies of selected Galactic star-forming regions (e.g. Orion A, Orion B, Galactic center, W43), as well as external galaxies (e.g. NGC 891) carried out with SHARC.

  7. The relationship between Class I and Class II methanol masers at high angular resolution

    Science.gov (United States)

    McCarthy, T. P.; Ellingsen, S. P.; Voronkov, M. A.; Cimò, G.

    2018-03-01

    We have used the Australia Telescope Compact Array (ATCA) to make the first high resolution observations of a large sample of class I methanol masers in the 95-GHz (80-71A+) transition. The target sources consist of a statistically complete sample of 6.7-GHz class II methanol masers with an associated 95-GHz class I methanol maser, enabling a detailed study of the relationship between the two methanol maser classes at arcsecond angular resolution. These sources have been previously observed at high resolution in the 36- and 44-GHz transitions, allowing comparison between all three class I maser transitions. In total, 172 95-GHz maser components were detected across the 32 target sources. We find that at high resolution, when considering matched maser components, a 3:1 flux density ratio is observed between the 95- and 44-GHz components, consistent with a number of previous lower angular resolution studies. The 95-GHz maser components appear to be preferentially located closer to the driving sources and this may indicate that this transition is more strongly inverted nearby to background continuum sources. We do not observe an elevated association rate between 95-GHz maser emission and more evolved sources, as indicated by the presence of 12.2-GHz class II masers. We find that in the majority of cases where both class I and class II methanol emission is observed, some component of the class I emission is associated with a likely outflow candidate.

  8. A Multi-instrument and Multi-wavelength High Angular Resolution Study of MWC 614: Quantum Heated Particles Inside the Disk Cavity

    Science.gov (United States)

    Kluska, Jacques; Kraus, Stefan; Davies, Claire L.; Harries, Tim; Willson, Matthew; Monnier, John D.; Aarnio, Alicia; Baron, Fabien; Millan-Gabet, Rafael; Ten Brummelaar, Theo; Che, Xiao; Hinkley, Sasha; Preibisch, Thomas; Sturmann, Judit; Sturmann, Laszlo; Touhami, Yamina

    2018-03-01

    High angular resolution observations of young stellar objects are required to study the inner astronomical units of protoplanetary disks in which the majority of planets form. As they evolve, gaps open up in the inner disk regions and the disks are fully dispersed within ∼10 Myr. MWC 614 is a pretransitional object with a ∼10 au radius gap. We present a set of high angular resolution observations of this object including SPHERE/ZIMPOL polarimetric and coronagraphic images in the visible, Keck/NIRC2 near-infrared (NIR) aperture masking observations, and Very Large Telescope Interferometer (AMBER, MIDI, and PIONIER) and Center for High Angular Resolution Astronomy (CLASSIC and CLIMB) long-baseline interferometry at infrared wavelengths. We find that all the observations are compatible with an inclined disk (i ∼ 55° at a position angle of ∼20°–30°). The mid-infrared data set confirms that the disk inner rim is at 12.3 ± 0.4 au from the central star. We determined an upper mass limit of 0.34 M ⊙ for a companion inside the cavity. Within the cavity, the NIR emission, usually associated with the dust sublimation region, is unusually extended (∼10 au, 30 times larger than the theoretical sublimation radius) and indicates a high dust temperature (T ∼ 1800 K). As a possible result of companion-induced dust segregation, quantum heated dust grains could explain the extended NIR emission with this high temperature. Our observations confirm the peculiar state of this object where the inner disk has already been accreted onto the star, exposing small particles inside the cavity to direct stellar radiation. Based on observations made with the Keck observatory (NASA program ID N104N2) and with ESO telescopes at the Paranal Observatory (ESO program IDs 073.C-0720, 077.C-0226, 077.C-0521, 083.C-0984, 087.C-0498(A), 190.C-0963, 095.C-0883) and with the Center for High Angular Resolution Astronomy observatory.

  9. High angular resolution observations of star-forming regions with BETTII and SOFIA

    Science.gov (United States)

    Rizzo, Maxime; Rinehart, Stephen; Mundy, Lee G.; Benford, Dominic J.; Dhabal, Arnab; Fixsen, Dale J.; Leisawitz, David; Maher, Stephen F.; Mentzell, Eric; Silverberg, Robert F.; Staguhn, Johannes; Veach, Todd; Cardiff BETTII Team

    2016-01-01

    High angular resolution observations in the far-infrared are important to understand the star formation process in embedded star clusters where extinction is large and stars form in close proximity. The material taking part in the star forming process is heated by the young stars and emits primarily in the far-IR; hence observations of the far-IR dust emission yields vital information about the gravitational potential, the mass and energy distribution, and core/star formation process. Previous observatories, such as Herschel, Spitzer and WISE lack the angular resolution required to study these dense star forming cores and are further limited by saturation in bright cores.The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is pioneering the path to sub-arcsecond resolution at far-IR wavelengths. This thesis talk discusses the instrumental challenges in building BETTII, as well as results from our SOFIA survey to illustrate the potential of higher-angular resolution observations. The 8m-long two element interferometer is being tested at NASA GSFC and is scheduled for first flight in fall 2016. BETTII will provide 0.5 to 1 arcsecond spatial resolution and spectral resolving power of 10 to 100 between 30 and 90 microns, where most of the dust continuum emission peaks in local star forming regions. It will achieve spatially-resolved spectroscopy of bright, dense cores with unprecedented high definition. This talk focuses on the main challenges and solutions associated with building BETTII: thermal stability, attitude/pointing control, and path length stabilization. In each of these areas we look at the trade-off between design, control, and knowledge in order to achieve the best-possible instrumental capability and sensitivity.As a first step towards resolving cluster cores, we surveyed 10 nearby star-forming clusters with SOFIA FORCAST at 11, 19, 31 and 37 microns. The FORCAST instrument has the highest angular resolution currently available in

  10. High-resolution angular and displacement sensing based on the excitation of surface plasma waves.

    Science.gov (United States)

    Margheri, G; Mannoni, A; Quercioli, F

    1997-07-01

    The possibility of building angular and displacement sensors based on the phenomenon of attenuated total reflection (ATR) is explored both numerically and experimentally. ATR occurs when a surface wave is excited by an incoming TM electromagnetic wave through a resonant phase-matching process, as in the Kretschmann coupling scheme. The reflected intensity strongly depends on the angle of incidence of the beam. We first show some computations of the sensitivity and the linearity of an ATR-based sensor, then proceed to the experiment, illustrating how an angular resolution of the order of 0.1 arc sec can be obtained with moderate effort. Finally we show how the sensor, combined with a simple optical arrangement, can be used to detect and measure nanometric displacements, as those provided by piezoelectric actuators.

  11. Accurate Mass Measurements for Planetary Microlensing Events Using High Angular Resolution Observations

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Beaulieu

    2018-04-01

    Full Text Available The microlensing technique is a unique method to hunt for cold planets over a range of mass and separation, orbiting all varieties of host stars in the disk of our galaxy. It provides precise mass-ratio and projected separations in units of the Einstein ring radius. In order to obtain the physical parameters (mass, distance, orbital separation of the system, it is necessary to combine the result of light curve modeling with lens mass-distance relations and/or perform a Bayesian analysis with a galactic model. A first mass-distance relation could be obtained from a constraint on the Einstein ring radius if the crossing time of the source over the caustic is measured. It could then be supplemented by secondary constraints such as parallax measurements, ideally by using coinciding ground and space-born observations. These are still subject to degeneracies, like the orbital motion of the lens. A third mass-distance relation can be obtained thanks to constraints on the lens luminosity using high angular resolution observations with 8 m class telescopes or the Hubble Space Telescope. The latter route, although quite inexpensive in telescope time is very effective. If we have to rely heavily on Bayesian analysis and limited constraints on mass-distance relations, the physical parameters are determined to 30–40% typically. In a handful of cases, ground-space parallax is a powerful route to get stronger constraint on masses. High angular resolution observations will be able to constrain the luminosity of the lenses in the majority of the cases, and in favorable circumstances it is possible to derive physical parameters to 10% or better. Moreover, these constraints will be obtained in most of the planets to be discovered by the Euclid and WFIRST satellites. We describe here the state-of-the-art approaches to measure lens masses and distances with an emphasis on high angular resolution observations. We will discuss the challenges, recent results and

  12. The impact of clustering and angular resolution on far-infrared and millimeter continuum observations

    Science.gov (United States)

    Béthermin, Matthieu; Wu, Hao-Yi; Lagache, Guilaine; Davidzon, Iary; Ponthieu, Nicolas; Cousin, Morgane; Wang, Lingyu; Doré, Olivier; Daddi, Emanuele; Lapi, Andrea

    2017-11-01

    Follow-up observations at high-angular resolution of bright submillimeter galaxies selected from deep extragalactic surveys have shown that the single-dish sources are comprised of a blend of several galaxies. Consequently, number counts derived from low- and high-angular-resolution observations are in tension. This demonstrates the importance of resolution effects at these wavelengths and the need for realistic simulations to explore them. We built a new 2 deg2 simulation of the extragalactic sky from the far-infrared to the submillimeter. It is based on an updated version of the 2SFM (two star-formation modes) galaxy evolution model. Using global galaxy properties generated by this model, we used an abundance-matching technique to populate a dark-matter lightcone and thus simulate the clustering. We produced maps from this simulation and extracted the sources, and we show that the limited angular resolution of single-dish instruments has a strong impact on (sub)millimeter continuum observations. Taking into account these resolution effects, we are reproducing a large set of observables, as number counts and their evolution with redshift and cosmic infrared background power spectra. Our simulation consistently describes the number counts from single-dish telescopes and interferometers. In particular, at 350 and 500 μm, we find that the number counts measured by Herschel between 5 and 50 mJy are biased towards high values by a factor 2, and that the redshift distributions are biased towards low redshifts. We also show that the clustering has an important impact on the Herschel pixel histogram used to derive number counts from P(D) analysis. We find that the brightest galaxy in the beam of a 500 μm Herschel source contributes on average to only 60% of the Herschel flux density, but that this number will rise to 95% for future millimeter surveys on 30 m-class telescopes (e.g., NIKA2 at IRAM). Finally, we show that the large number density of red Herschel sources

  13. Quality assessment of high angular resolution diffusion imaging data using bootstrap on Q-ball reconstruction.

    Science.gov (United States)

    Cohen-Adad, Julien; Descoteaux, Maxime; Wald, Lawrence L

    2011-05-01

    To develop a bootstrap method to assess the quality of High Angular Resolution Diffusion Imaging (HARDI) data using Q-Ball imaging (QBI) reconstruction. HARDI data were re-shuffled using regular bootstrap with jackknife sampling. For each bootstrap dataset, the diffusion orientation distribution function (ODF) was estimated voxel-wise using QBI reconstruction based on spherical harmonics functions. The reproducibility of the ODF was assessed using the Jensen-Shannon divergence (JSD) and the angular confidence interval was derived for the first and the second ODF maxima. The sensitivity of the bootstrap method was evaluated on a human subject by adding synthetic noise to the data, by acquiring a map of image signal-to-noise ratio (SNR) and by varying the echo time and the b-value. The JSD was directly linked to the image SNR. The impact of echo times and b-values was reflected by both the JSD and the angular confidence interval, proving the usefulness of the bootstrap method to evaluate specific features of HARDI data. The bootstrap method can effectively assess the quality of HARDI data and can be used to evaluate new hardware and pulse sequences, perform multifiber probabilistic tractography, and provide reliability metrics to support clinical studies. Copyright © 2011 Wiley-Liss, Inc.

  14. Discrete time interval measurement system: fundamentals, resolution and errors in the measurement of angular vibrations

    International Nuclear Information System (INIS)

    Gómez de León, F C; Meroño Pérez, P A

    2010-01-01

    The traditional method for measuring the velocity and the angular vibration in the shaft of rotating machines using incremental encoders is based on counting the pulses at given time intervals. This method is generically called the time interval measurement system (TIMS). A variant of this method that we have developed in this work consists of measuring the corresponding time of each pulse from the encoder and sampling the signal by means of an A/D converter as if it were an analog signal, that is to say, in discrete time. For this reason, we have denominated this method as the discrete time interval measurement system (DTIMS). This measurement system provides a substantial improvement in the precision and frequency resolution compared with the traditional method of counting pulses. In addition, this method permits modification of the width of some pulses in order to obtain a mark-phase on every lap. This paper explains the theoretical fundamentals of the DTIMS and its application for measuring the angular vibrations of rotating machines. It also displays the required relationship between the sampling rate of the signal, the number of pulses of the encoder and the rotating velocity in order to obtain the required resolution and to delimit the methodological errors in the measurement

  15. Non Local Spatial and Angular Matching: Enabling higher spatial resolution diffusion MRI datasets through adaptive denoising.

    Science.gov (United States)

    St-Jean, Samuel; Coupé, Pierrick; Descoteaux, Maxime

    2016-08-01

    Diffusion magnetic resonance imaging (MRI) datasets suffer from low Signal-to-Noise Ratio (SNR), especially at high b-values. Acquiring data at high b-values contains relevant information and is now of great interest for microstructural and connectomics studies. High noise levels bias the measurements due to the non-Gaussian nature of the noise, which in turn can lead to a false and biased estimation of the diffusion parameters. Additionally, the usage of in-plane acceleration techniques during the acquisition leads to a spatially varying noise distribution, which depends on the parallel acceleration method implemented on the scanner. This paper proposes a novel diffusion MRI denoising technique that can be used on all existing data, without adding to the scanning time. We first apply a statistical framework to convert both stationary and non stationary Rician and non central Chi distributed noise to Gaussian distributed noise, effectively removing the bias. We then introduce a spatially and angular adaptive denoising technique, the Non Local Spatial and Angular Matching (NLSAM) algorithm. Each volume is first decomposed in small 4D overlapping patches, thus capturing the spatial and angular structure of the diffusion data, and a dictionary of atoms is learned on those patches. A local sparse decomposition is then found by bounding the reconstruction error with the local noise variance. We compare against three other state-of-the-art denoising methods and show quantitative local and connectivity results on a synthetic phantom and on an in-vivo high resolution dataset. Overall, our method restores perceptual information, removes the noise bias in common diffusion metrics, restores the extracted peaks coherence and improves reproducibility of tractography on the synthetic dataset. On the 1.2 mm high resolution in-vivo dataset, our denoising improves the visual quality of the data and reduces the number of spurious tracts when compared to the noisy acquisition. Our

  16. Converting Multi-Shell and Diffusion Spectrum Imaging to High Angular Resolution Diffusion Imaging.

    Science.gov (United States)

    Yeh, Fang-Cheng; Verstynen, Timothy D

    2016-01-01

    Multi-shell and diffusion spectrum imaging (DSI) are becoming increasingly popular methods of acquiring diffusion MRI data in a research context. However, single-shell acquisitions, such as diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), still remain the most common acquisition schemes in practice. Here we tested whether multi-shell and DSI data have conversion flexibility to be interpolated into corresponding HARDI data. We acquired multi-shell and DSI data on both a phantom and in vivo human tissue and converted them to HARDI. The correlation and difference between their diffusion signals, anisotropy values, diffusivity measurements, fiber orientations, connectivity matrices, and network measures were examined. Our analysis result showed that the diffusion signals, anisotropy, diffusivity, and connectivity matrix of the HARDI converted from multi-shell and DSI were highly correlated with those of the HARDI acquired on the MR scanner, with correlation coefficients around 0.8~0.9. The average angular error between converted and original HARDI was 20.7° at voxels with signal-to-noise ratios greater than 5. The network topology measures had less than 2% difference, whereas the average nodal measures had a percentage difference around 4~7%. In general, multi-shell and DSI acquisitions can be converted to their corresponding single-shell HARDI with high fidelity. This supports multi-shell and DSI acquisitions over HARDI acquisition as the scheme of choice for diffusion acquisitions.

  17. High resolution gamma-ray spectroscopy and the fascinating angular momentum realm of the atomic nucleus

    International Nuclear Information System (INIS)

    Riley, M A; Simpson, J; Paul, E S

    2016-01-01

    In 1974 Aage Bohr and Ben Mottelson predicted the different ‘phases’ that may be expected in deformed nuclei as a function of increasing angular momentum and excitation energy all the way up to the fission limit. While admitting their picture was highly conjectural they confidently stated ‘...with the ingenious experimental approaches that are being developed, we may look forward with excitement to the detailed spectroscopic studies that will illuminate the behaviour of the spinning quantised nucleus’ . High resolution gamma-ray spectroscopy has indeed been a major tool in studying the structure of atomic nuclei and has witnessed numerous significant advances over the last four decades. This article will select highlights from investigations at the Niels Bohr Institute, Denmark, and Daresbury Laboratory, UK, in the late 1970s and early 1980s, some of which have continued at other national laboratories in Europe and the USA to the present day. These studies illustrate the remarkable diversity of phenomena and symmetries exhibited by nuclei in the angular momentum–excitation energy plane that continue to surprise and fascinate scientists. (invited comment)

  18. Examining the Angular Resolution of the Astro-H's Soft X-Ray Telescopes

    Science.gov (United States)

    Sato, Toshiki; Iizuka, Ryo; Ishida, Manabu; Kikuchi, Naomichi; Maeda, Yoshitomo; Kurashima, Sho; Nakaniwa, Nozomi; Tomikawa, Kazuki; Hayashi, Takayuki; Mori, Hideyuki; hide

    2016-01-01

    The international x-ray observatory ASTRO-H was renamed Hitomi after launch. It covers a wide energy range from a few hundred eV to 600 keV. It is equipped with two soft x-ray telescopes (SXTs: SXT-I and SXT-S) for imaging the soft x-ray sky up to 12 keV, which focus an image onto the respective focal-plane detectors: CCD camera (SXI) and a calorimeter (SXS). The SXTs are fabricated in a quadrant unit. The angular resolution in half-power diameter (HPD) of each quadrant of the SXTs ranges between 1.1 and 1.4 arc min at 4.51 keV. It was also found that one quadrant has an energy dependence on the HPD. We examine the angular resolution with spot scan measurements. In order to understand the cause of imaging capability deterioration and to reflect it to the future telescope development, we carried out spot scan measurements, in which we illuminate all over the aperture of each quadrant with a square beam 8 mm on a side. Based on the scan results, we made maps of image blurring and a focus position. The former and the latter reflect figure error and positioning error, respectively, of the foils that are within the incident 8 mm x 8 mm beam. As a result, we estimated those errors in a quadrant to be approx. 0.9 to 1.0 and approx. 0.6 to 0.9 arc min, respectively. We found that the larger the positioning error in a quadrant is, the larger its HPD is. The HPD map, which manifests the local image blurring, is very similar from quadrant to quadrant, but the map of the focus position is different from location to location in each telescope. It is also found that the difference in local performance causes energy dependence of the HPD.

  19. ONE-DIMENSIONAL LIGHT BEAM WIDENING USING PRISMS FOR INCREASE OF SPECTROMETER SPECTRAL RESOLUTION AND ANGULAR DISPERSION

    Directory of Open Access Journals (Sweden)

    I. M. Gulis

    2016-01-01

    Full Text Available The increase of angular dispersion and slit resolution limit of grating spectrometers by means of variation of grating parameters is limited by its period and allowable order of diffraction. The special solutions (echelle, holographic, immersion gratings are acceptable in a limited parameter range and are technologically complex in fabrication, thus hardly applicable to instruments of mass production. We propose to decrease slit resolution limit by one-dimensional beam widening in dispersion plane by means of passing it through oblique prism before incidence onto diffraction grating. The increase of angular dispersion can be achieved by narrowing of dispersed beams after grating while passing through other oblique prism. We prove that slit resolution limit in such a system changes approximately as multiplied by angular magnification of the first prism (that is less than 1 times. Also angular dispersion changed approximately as multiplied by angular magnification of the second prism. The Fresnel reflection from the faces of prisms is analyzed. Accounting for that factor gives the increase of resolution about 1,4–1,6 times without loss of light (and can be 2 and more times while using anti-reflective coating. The proposed method is different from the similar ones first of all by its simplicity because it uses simple optical elements – plane reflective grating and thin prisms. It can be applied to amend the analytical characteristics of dispersive spectrometers, first of all the small-sized ones. 

  20. High Angular Resolution Measurements of the Anisotropy of Reflectance of Sea Ice and Snow

    Science.gov (United States)

    Goyens, C.; Marty, S.; Leymarie, E.; Antoine, D.; Babin, M.; Bélanger, S.

    2018-01-01

    We introduce a new method to determine the anisotropy of reflectance of sea ice and snow at spatial scales from 1 m2 to 80 m2 using a multispectral circular fish-eye radiance camera (CE600). The CE600 allows measuring radiance simultaneously in all directions of a hemisphere at a 1° angular resolution. The spectral characteristics of the reflectance and its dependency on illumination conditions obtained from the camera are compared to those obtained with a hyperspectral field spectroradiometer manufactured by Analytical Spectral Device, Inc. (ASD). Results confirm the potential of the CE600, with the suggested measurement setup and data processing, to measure commensurable sea ice and snow hemispherical-directional reflectance factor, HDRF, values. Compared to the ASD, the reflectance anisotropy measured with the CE600 provides much higher resolution in terms of directional reflectance (N = 16,020). The hyperangular resolution allows detecting features that were overlooked using the ASD due to its limited number of measurement angles (N = 25). This data set of HDRF further documents variations in the anisotropy of the reflectance of snow and ice with the geometry of observation and illumination conditions and its spectral and spatial scale dependency. Finally, in order to reproduce the hyperangular CE600 reflectance measurements over the entire 400-900 nm spectral range, a regression-based method is proposed to combine the ASD and CE600 measurements. Results confirm that both instruments may be used in synergy to construct a hyperangular and hyperspectral snow and ice reflectance anisotropy data set.

  1. Importance of energy and angular resolutions in top-hat electrostatic analysers for solar wind proton measurements

    Science.gov (United States)

    De Marco, R.; Marcucci, M. F.; Bruno, R.; D'Amicis, R.; Servidio, S.; Valentini, F.; Lavraud, B.; Louarn, P.; Salatti, M.

    2016-08-01

    We use a numerical code which reproduces the angular/energy response of a typical top-hat electrostatic analyser starting from solar wind proton velocity distribution functions (VDFs) generated by numerical simulations. The simulations are based on the Hybrid Vlasov-Maxwell numerical algorithm which integrates the Vlasov equation for the ion distribution function, while the electrons are treated as a fluid. A virtual satellite launched through the simulation box measures the particle VDFs. Such VDFs are moved from the simulation Cartesian grid to energy-angular coordinates to mimic the response of a real sensor in the solar wind. Different energy-angular resolutions of the analyser are investigated in order to understand the influence of the phase-space resolution in existing and upcoming space missions, with regards to determining the key parameters of plasma dynamics.

  2. Measurement method for roll angular displacement with a high resolution by using diffraction gratings and a heterodyne interferometer

    International Nuclear Information System (INIS)

    Tang, Shanzhi; Wang, Zhao; Gao, Jianmin; Guo, Junjie

    2014-01-01

    The roll angle measurement is difficult to be achieved directly using a typical commercial interferometer due to its low sensitivity in axial direction, where the axial direction is orthogonal to the plane of the roll angular displacement. A roll angle measurement method combined diffraction gratings with a laser heterodyne interferometer is discussed in this paper. The diffraction grating placed in the plane of a roll angular displacement and the interferometer arranged in the plane's orthogonal direction, constitute the measurement pattern for the roll angle with high resolution. The roll angular displacement, considered as the linear, can be tested precisely when the corresponding angle is very small. Using the proposed method, the angle roll measurement obtains the high resolution of 0.002 ″ . Experiment has proved its feasibility and practicability

  3. High angular resolution diffusion imaging with stimulated echoes: compensation and correction in experiment design and analysis.

    Science.gov (United States)

    Lundell, Henrik; Alexander, Daniel C; Dyrby, Tim B

    2014-08-01

    Stimulated echo acquisition mode (STEAM) diffusion MRI can be advantageous over pulsed-gradient spin-echo (PGSE) for diffusion times that are long compared with T2 . It therefore has potential for biomedical diffusion imaging applications at 7T and above where T2 is short. However, gradient pulses other than the diffusion gradients in the STEAM sequence contribute much greater diffusion weighting than in PGSE and lead to a disrupted experimental design. Here, we introduce a simple compensation to the STEAM acquisition that avoids the orientational bias and disrupted experiment design that these gradient pulses can otherwise produce. The compensation is simple to implement by adjusting the gradient vectors in the diffusion pulses of the STEAM sequence, so that the net effective gradient vector including contributions from diffusion and other gradient pulses is as the experiment intends. High angular resolution diffusion imaging (HARDI) data were acquired with and without the proposed compensation. The data were processed to derive standard diffusion tensor imaging (DTI) maps, which highlight the need for the compensation. Ignoring the other gradient pulses, a bias in DTI parameters from STEAM acquisition is found, due both to confounds in the analysis and the experiment design. Retrospectively correcting the analysis with a calculation of the full B matrix can partly correct for these confounds, but an acquisition that is compensated as proposed is needed to remove the effect entirely. © 2014 The Authors. NMR in Biomedicine published by John Wiley & Sons, Ltd.

  4. Mass loss of evolved massive stars: the circumstellar environment at high angular resolution

    International Nuclear Information System (INIS)

    Montarges, Miguel

    2014-01-01

    Mass loss of evolved stars is still largely mysterious, despite its importance as the main evolution engine for the chemical composition of the interstellar medium. For red supergiants (RSG), the triggering of the outflow and the mechanism of dust condensation remain unknown. Concerning red giant stars, we still do not know how their mass loss is able to form a bipolar planetary nebula. During my PhD thesis, I observed evolved stars with high angular resolution techniques. They allowed us to study the surface and the close environment of these stars, from where mass loss originates. With near-infrared interferometric observations, I characterized the water vapor and carbon monoxide envelope of the nearby RSG Betelgeuse. I also monitored a hot spot on its surface and analyzed the structure of its convection, as well as that of Antares (another very nearby supergiant) thanks to radiative hydrodynamical simulations. Diffraction-limited imaging techniques (near-infrared adaptive optics, ultraviolet space telescope) allowed me to observe the evolution of inhomogeneities in the circumstellar envelope of Betelgeuse and to discover a circumstellar disk around L2 Puppis, an asymptotic giant branch star. These multi-scale and multi-wavelength observations obtained at several epochs allowed us to monitor the evolution of the structures and to derive information on the dynamics of the stellar environment. With a wider stellar sample expected in the next few years, this observing program will allow a better understanding of the mass loss of evolved stars. (author)

  5. Sub-Airy disk angular resolution with high dynamic range in the near-infrared

    Directory of Open Access Journals (Sweden)

    Richichi A.

    2011-07-01

    Full Text Available Lunar occultations (LO are a simple and effective high angular resolution method, with minimum requirements in instrumentation and telescope time. They rely on the analysis of the diffraction fringes created by the lunar limb. The diffraction phenomen occurs in space, and as a result LO are highly insensitive to most of the degrading effects that limit the performance of traditional single telescope and long-baseline interferometric techniques used for direct detection of faint, close companions to bright stars. We present very recent results obtained with the technique of lunar occultations in the near-IR, showing the detection of companions with very high dynamic range as close as few milliarcseconds to the primary star. We discuss the potential improvements that could be made, to increase further the current performance. Of course, LO are fixed-time events applicable only to sources which happen to lie on the Moon’s apparent orbit. However, with the continuously increasing numbers of potential exoplanets and brown dwarfs beign discovered, the frequency of such events is not negligible. I will list some of the most favorable potential LO in the near future, to be observed from major observatories.

  6. Development of insula connectivity between ages 12 and 30 revealed by high angular resolution diffusion imaging.

    Science.gov (United States)

    Dennis, Emily L; Jahanshad, Neda; McMahon, Katie L; de Zubicaray, Greig I; Martin, Nicholas G; Hickie, Ian B; Toga, Arthur W; Wright, Margaret J; Thompson, Paul M

    2014-04-01

    The insula, hidden deep within the Sylvian fissures, has proven difficult to study from a connectivity perspective. Most of our current information on the anatomical connectivity of the insula comes from studies of nonhuman primates and post mortem human dissections. To date, only two neuroimaging studies have successfully examined the connectivity of the insula. Here we examine how the connectivity of the insula develops between ages 12 and 30, in 307 young adolescent and adult subjects scanned with 4-Tesla high angular resolution diffusion imaging (HARDI). The density of fiber connections between the insula and the frontal and parietal cortex decreased with age, but the connection density between the insula and the temporal cortex generally increased with age. This trajectory is in line with well-known patterns of cortical development in these regions. In addition, males and females showed different developmental trajectories for the connection between the left insula and the left precentral gyrus. The insula plays many different roles, some of them affected in neuropsychiatric disorders; this information on the insula's connectivity may help efforts to elucidate mechanisms of brain disorders in which it is implicated. Copyright © 2013 Wiley Periodicals, Inc.

  7. Angular difference feature extraction for urban scene classification using ZY-3 multi-angle high-resolution satellite imagery

    Science.gov (United States)

    Huang, Xin; Chen, Huijun; Gong, Jianya

    2018-01-01

    Spaceborne multi-angle images with a high-resolution are capable of simultaneously providing spatial details and three-dimensional (3D) information to support detailed and accurate classification of complex urban scenes. In recent years, satellite-derived digital surface models (DSMs) have been increasingly utilized to provide height information to complement spectral properties for urban classification. However, in such a way, the multi-angle information is not effectively exploited, which is mainly due to the errors and difficulties of the multi-view image matching and the inaccuracy of the generated DSM over complex and dense urban scenes. Therefore, it is still a challenging task to effectively exploit the available angular information from high-resolution multi-angle images. In this paper, we investigate the potential for classifying urban scenes based on local angular properties characterized from high-resolution ZY-3 multi-view images. Specifically, three categories of angular difference features (ADFs) are proposed to describe the angular information at three levels (i.e., pixel, feature, and label levels): (1) ADF-pixel: the angular information is directly extrapolated by pixel comparison between the multi-angle images; (2) ADF-feature: the angular differences are described in the feature domains by comparing the differences between the multi-angle spatial features (e.g., morphological attribute profiles (APs)). (3) ADF-label: label-level angular features are proposed based on a group of urban primitives (e.g., buildings and shadows), in order to describe the specific angular information related to the types of primitive classes. In addition, we utilize spatial-contextual information to refine the multi-level ADF features using superpixel segmentation, for the purpose of alleviating the effects of salt-and-pepper noise and representing the main angular characteristics within a local area. The experiments on ZY-3 multi-angle images confirm that the proposed

  8. Intelligent Cognitive Radio Models for Enhancing Future Radio Astronomy Observations

    Directory of Open Access Journals (Sweden)

    Ayodele Abiola Periola

    2016-01-01

    Full Text Available Radio astronomy organisations desire to optimise the terrestrial radio astronomy observations by mitigating against interference and enhancing angular resolution. Ground telescopes (GTs experience interference from intersatellite links (ISLs. Astronomy source radio signals received by GTs are analysed at the high performance computing (HPC infrastructure. Furthermore, observation limitation conditions prevent GTs from conducting radio astronomy observations all the time, thereby causing low HPC utilisation. This paper proposes mechanisms that protect GTs from ISL interference without permanent prevention of ISL data transmission and enhance angular resolution. The ISL transmits data by taking advantage of similarities in the sequence of observed astronomy sources to increase ISL connection duration. In addition, the paper proposes a mechanism that enhances angular resolution by using reconfigurable earth stations. Furthermore, the paper presents the opportunistic computing scheme (OCS to enhance HPC utilisation. OCS enables the underutilised HPC to be used to train learning algorithms of a cognitive base station. The performances of the three mechanisms are evaluated. Simulations show that the proposed mechanisms protect GTs from ISL interference, enhance angular resolution, and improve HPC utilisation.

  9. Lightweight and High-Resolution Single Crystal Silicon Optics for X-ray Astronomy

    Science.gov (United States)

    Zhang, William W.; Biskach, Michael P.; Chan, Kai-Wing; Mazzarella, James R.; McClelland, Ryan S.; Riveros, Raul E.; Saha, Timo T.; Solly, Peter M.

    2016-01-01

    We describe an approach to building mirror assemblies for next generation X-ray telescopes. It incorporates knowledge and lessons learned from building existing telescopes, including Chandra, XMM-Newton, Suzaku, and NuSTAR, as well as from our direct experience of the last 15 years developing mirror technology for the Constellation-X and International X-ray Observatory mission concepts. This approach combines single crystal silicon and precision polishing, thus has the potential of achieving the highest possible angular resolution with the least possible mass. Moreover, it is simple, consisting of several technical elements that can be developed independently in parallel. Lastly, it is highly amenable to mass production, therefore enabling the making of telescopes of very large photon collecting areas.

  10. Method of separation of air showers initiated by γ-quanta and protons using Cherenkov light angular characteristics in combination and angular resolution estimate for an array of several optical telescopes

    International Nuclear Information System (INIS)

    Anokhina, A.M.; Galkin, V.I.; Ivanenko, I.P.; Roganova, T.M.

    1990-01-01

    Computer simulation of optical characteristics of air showers was carried out. On the basis of multidimensional analysis of Cherenkov light angular distribution possibility is considered to distinguish γ-showers from proton showers. Also an estimate for angular resolution is given for an array of five optical telescopes situated at Mt.Aragats. 7 refs.; 10 figs.; 11 tabs

  11. Arbitrary Angular Momentum Electron Repulsion Integrals with Graphical Processing Units: Application to the Resolution of Identity Hartree-Fock Method.

    Science.gov (United States)

    Kalinowski, Jaroslaw; Wennmohs, Frank; Neese, Frank

    2017-07-11

    A resolution of identity based implementation of the Hartree-Fock method on graphical processing units (GPUs) is presented that is capable of handling basis functions with arbitrary angular momentum. For practical reasons, only functions up to (ff|f) angular momentum are presently calculated on the GPU, thus leaving the calculation of higher angular momenta integrals on the CPU of the hybrid CPU-GPU environment. Speedups of up to a factor of 30 are demonstrated relative to state-of-the-art serial and parallel CPU implementations. Benchmark calculations with over 3500 contracted basis functions (def2-SVP or def2-TZVP basis sets) are reported. The presented implementation supports all devices with OpenCL support and is capable of utilizing multiple GPU cards over either MPI or OpenCL itself.

  12. Design and performance of a high rate, high angular resolution beam telescope used for crystal channeling studies

    International Nuclear Information System (INIS)

    Pesaresi, M; Ferguson, W; Fulcher, J; Hall, G; Raymond, M; Ryan, M; Zorba, O

    2011-01-01

    A charged particle telescope has been constructed for data taking at high rates in a CERN 400 GeV/c proton beam line. It utilises ten planes of silicon microstrip sensors, arranged as five pairs each measuring two orthogonal coordinates, with an active area of 3.8 x 3.8 cm 2 . The objective was to provide excellent angular and spatial resolution for measuring the trajectories of incident and outgoing particles. The apparatus has a long baseline, of approximately 10 m in each arm, and achieves an angular resolution in the incoming arm of 2.8 μrad and a total angular resolution on the difference of the two arms of 5.2 μrad, with performance limited by multiple scattering in the sensor layers. The sensors are instrumented by a system based on the CMS Tracker electronic readout chain, including analogue signal readout for optimal spatial resolution. The system profits from modified CMS software and hardware to provide a data acquisition capable of peak trigger rates of at least 7 kHz. We describe the sensor readout, electronic hardware and software, together with the measured performance of the telescope during studies of crystal channeling for the UA9 collaboration. Measurements of a previously unobserved periodic movement of the beam are also presented and the significance of such an effect for precise studies such as for channeling is discussed.

  13. The Fourier-Kelvin Stellar Interferometer a Low Complexity, Low Cost Space Mission for High-Resolution Astronomy and Direct Exoplanet Detection

    Science.gov (United States)

    Barry, R. K.; Danchi, W. C.; Deming, L. D.; Richardson, L. J.; Kuchner, M. J.; Seager, S.; Frey, B. J.; Martino, A. J.; Lee, K. A.; Zuray, M.; hide

    2006-01-01

    The Fourier-Kelvin Stellar Interferometer (FKSI) is a mission concept for a spacecraft-borne nulling interferometer for high-resolution astronomy and the direct detection of exoplanets and assay of their environments and atmospheres. FKSI is a high angular resolution system operating in the near to midinfrared spectral region and is a scientific and technological pathfinder to the Darwin and Terrestrial Planet Finder (TPF) missions. The instrument is configured with an optical system consisting, depending on configuration, of two 0.5 - 1.0 m telescopes on a 12.5 - 20 m boom feeding a symmetric, dual Mach- Zehnder beam combiner. We report on progress on our nulling testbed including the design of an optical pathlength null-tracking control system and development of a testing regime for hollow-core fiber waveguides proposed for use in wavefront cleanup. We also report results of integrated simulation studies of the planet detection performance of FKSI and results from an in-depth control system and residual optical pathlength jitter analysis.

  14. The Concordia station on Antarctica plateau: the best site on Earth for High Angular Resolution and High Contrast Imaging

    Science.gov (United States)

    Fossat, E.; Aristidi, E.; Agabi, K.

    On the Antarctica plateau, a joint project of french and italian polar programmes in just near completion: the Concordia station will be open for winterover operation in 2005. The high altitude and high latitude of this site, the exceptionally cold, clear and stable atmosphere, the almost indefinitely flat snow surface and the not so difficult access make this site the most promising on Earth for future ground based astronomical projects in various fields, including High Angular Resolution and High Contrast Imaging.

  15. SOUTHERN MASSIVE STARS AT HIGH ANGULAR RESOLUTION: OBSERVATIONAL CAMPAIGN AND COMPANION DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    Sana, H. [European Space Agency/Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Le Bouquin, J.-B.; Duvert, G.; Zins, G. [Université Grenoble Alpes, IPAG, F-38000 Grenoble (France); Lacour, S.; Gauchet, L.; Pickel, D. [LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris-Diderot, Paris Sciences et Lettres, 5 Place Jules Janssen, F-92195 Meudon (France); Berger, J.-P. [European Southern Observatory, Schwarzschild-Str. 2, D-85748 Garching bei München (Germany); Norris, B. [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Olofsson, J. [Max-Planck-Institut für Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Absil, O. [Département d' Astrophysique, Géophysique et Océanographie, Université de Liège, 17 Allée du Six Août, B-4000 Liège (Belgium); De Koter, A. [Astrophysical Institute Anton Pannekoek, Universiteit van Amsterdam, Science Park 904, 1098XH Amsterdam (Netherlands); Kratter, K. [JILA, 440 UCB, University of Colorado, Boulder, CO 80309-0440 (United States); Schnurr, O. [Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); Zinnecker, H., E-mail: hsana@stsci.edu [Deutsches SOFIA Instituut, SOFIA Science Center, NASA Ames Research Center, Mail Stop N232-12, Moffett Field, CA 94035 (United States)

    2014-11-01

    Multiplicity is one of the most fundamental observable properties of massive O-type stars and offers a promising way to discriminate between massive star formation theories. Nevertheless, companions at separations between 1 and 100 milliarcsec (mas) remain mostly unknown due to intrinsic observational limitations. At a typical distance of 2 kpc, this corresponds to projected physical separations of 2-200 AU. The Southern MAssive Stars at High angular resolution survey (SMaSH+) was designed to fill this gap by providing the first systematic interferometric survey of Galactic massive stars. We observed 117 O-type stars with VLTI/PIONIER and 162 O-type stars with NACO/Sparse Aperture Masking (SAM), probing the separation ranges 1-45 and 30-250 mas and brightness contrasts of ΔH < 4 and ΔH < 5, respectively. Taking advantage of NACO's field of view, we further uniformly searched for visual companions in an 8'' radius down to ΔH = 8. This paper describes observations and data analysis, reports the discovery of almost 200 new companions in the separation range from 1 mas to 8'' and presents a catalog of detections, including the first resolved measurements of over a dozen known long-period spectroscopic binaries. Excluding known runaway stars for which no companions are detected, 96 objects in our main sample (δ < 0°; H < 7.5) were observed both with PIONIER and NACO/SAM. The fraction of these stars with at least one resolved companion within 200 mas is 0.53. Accounting for known but unresolved spectroscopic or eclipsing companions, the multiplicity fraction at separation ρ < 8'' increases to f {sub m} = 0.91 ± 0.03. The fraction of luminosity class V stars that have a bound companion reaches 100% at 30 mas while their average number of physically connected companions within 8'' is f {sub c} = 2.2 ± 0.3. This demonstrates that massive stars form nearly exclusively in multiple systems. The nine non-thermal radio

  16. The X-Ray Optics for the High Angular Resolution Imager (HARI)

    Science.gov (United States)

    Weisskopf, M. C.

    2010-01-01

    This slide presentation shows the basic parameters of the x-ray optics, the housing,a graph of the effective area vs energy, another graph showing the angular off-set vs HEW, and a series of graphs showing the detector offsets and tilts,

  17. Angular-resolution and material-characterization measurements for a dual-particle imaging system with mixed-oxide fuel

    Energy Technology Data Exchange (ETDEWEB)

    Poitrasson-Rivière, Alexis, E-mail: alexispr@umich.edu [Department of Nuclear Engineering & Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Polack, J. Kyle; Hamel, Michael C.; Klemm, Dietrich D.; Ito, Kai; McSpaden, Alexander T.; Flaska, Marek; Clarke, Shaun D.; Pozzi, Sara A. [Department of Nuclear Engineering & Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Tomanin, Alice [Lainsa-Italia S.R.L., Via E. Fermi 2749, 21027 Ispra, VA (Italy); Peerani, Paolo [European Commission, Joint Research Centre, Institute for Transuranium Elements, 21027 Ispra, VA (Italy)

    2015-10-11

    A dual-particle imaging (DPI) system, capable of simultaneously imaging fast neutrons and gamma rays, has been operated in the presence of mixed-oxide (MOX) fuel to assess the system's angular resolution and material-characterization capabilities. The detection principle is based on the scattering physics of neutrons (elastic scattering) and gamma rays (Compton scattering) in organic and inorganic scintillators. The detection system is designed as a combination of a two-plane Compton camera and a neutron-scatter camera. The front plane consists of EJ-309 liquid scintillators and the back plane consists of interleaved EJ-309 and NaI(Tl) scintillators. MCNPX-PoliMi was used to optimize the geometry of the system and the resulting prototype was built and tested using a Cf-252 source as an SNM surrogate. A software package was developed to acquire and process data in real time. The software was used for a measurement campaign to assess the angular resolution of the imaging system with MOX samples. Measurements of two MOX canisters of similar isotopics and intensity were performed for 6 different canister separations (from 5° to 30°, corresponding to distances of 21 cm and 131 cm, respectively). The measurements yielded a minimum separation of 20° at 2.5 m (86-cm separation) required to see 2 separate hot spots. Additionally, the results displayed good agreement with MCNPX-PoliMi simulations. These results indicate an angular resolution between 15° and 20°, given the 5° step. Coupled with its large field of view, and its capability to differentiate between spontaneous fission and (α,n) sources, the DPI system shows its potential for nuclear-nonproliferation applications.

  18. Super-resolution and ultra-sensitivity of angular rotation measurement based on SU(1,1) interferometers using homodyne detection

    Science.gov (United States)

    Liu, Jun; Li, Shitao; Wei, Dong; Gao, Hong; Li, Fuli

    2018-02-01

    We theoretically explore the angular rotation measurement sensitivity of SU(1,1) interferometers with a coherent beam and a vacuum beam input by using orbital angular momentum (OAM). Compared with the OAM in an SU(2) interferometer, the SU(1,1) interferometer employing homodyne detection can further surpass the angular rotation shot noise limit \\tfrac{1}{2l\\sqrt{N}} and improve the resolution and sensitivity of angular rotation measurement. Two models are considered, one is that OAM is carried by a probe beam and the other one is a pump beam with the OAM. The sensitivity can be improved by higher OAM and nonlinear process with a large gain. The resolution can be enhanced in the case that the pump beam has OAM. Moreover, we present a brief discussion on the variation of resolution and sensitivity in the presence of photon loss.

  19. High mass star formation to the extremes: NGC 3603 at high angular resolution in the near-infrared

    International Nuclear Information System (INIS)

    Nuernberger, Dieter E A

    2008-01-01

    High angular resolution observations play a decisive role for our understanding of high mass star formation processes, both within our Galaxy and in extragalactic starburst regions. We take the Galactic starburst template NGC 3603 as paradigm and report here on high angular resolution JHK s L' observations of the enigmatic, highly reddened sources IRS 9A-C in the NGC 3603 region, which were performed with NACO at ESO's Very Large Telescope Yepun. These broad-band imaging data strongly support the classification of IRS 9A-C as high mass protostellar candidates. We also confirm unambiguously the membership of IRS 9A-C with the NGC 3603 region as gas and dust is seen to be stripped off from their circumstellar envelopes by strong stellar winds, originating from the high mass main sequence stars of the nearby OB cluster. The orientation of these gas and dust streamers coincides with that of a very faint, only marginally detected mini-pillar protruding from the adjacent molecular clump NGC 3603 MM 2. The L' data show extended envelopes around IRS 9A-C and reveal sub-structures therein which are indicative for non-spherically distributed material. It seems obvious that protostellar mass outflows are at work to clear cavities along the polar axes of the central protostar, and / or that circumstellar disks are taking shape.

  20. High mass star formation to the extremes: NGC 3603 at high angular resolution in the near-infrared

    Energy Technology Data Exchange (ETDEWEB)

    Nuernberger, Dieter E A [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)], E-mail: dnuernbe@eso.org

    2008-10-15

    High angular resolution observations play a decisive role for our understanding of high mass star formation processes, both within our Galaxy and in extragalactic starburst regions. We take the Galactic starburst template NGC 3603 as paradigm and report here on high angular resolution JHK{sub s}L' observations of the enigmatic, highly reddened sources IRS 9A-C in the NGC 3603 region, which were performed with NACO at ESO's Very Large Telescope Yepun. These broad-band imaging data strongly support the classification of IRS 9A-C as high mass protostellar candidates. We also confirm unambiguously the membership of IRS 9A-C with the NGC 3603 region as gas and dust is seen to be stripped off from their circumstellar envelopes by strong stellar winds, originating from the high mass main sequence stars of the nearby OB cluster. The orientation of these gas and dust streamers coincides with that of a very faint, only marginally detected mini-pillar protruding from the adjacent molecular clump NGC 3603 MM 2. The L' data show extended envelopes around IRS 9A-C and reveal sub-structures therein which are indicative for non-spherically distributed material. It seems obvious that protostellar mass outflows are at work to clear cavities along the polar axes of the central protostar, and / or that circumstellar disks are taking shape.

  1. The multiplicity of massive stars: A high angular resolution survey with the HST fine guidance sensor

    International Nuclear Information System (INIS)

    Aldoretta, E. J.; Gies, D. R.; Henry, T. J.; Jao, W.-C.; Norris, R. P.

    2015-01-01

    We present the results of an all-sky survey made with the Fine Guidance Sensor on the Hubble Space Telescope to search for angularly resolved binary systems among massive stars. The sample of 224 stars is comprised mainly of Galactic O- and B-type stars and luminous blue variables, plus a few luminous stars in the Large Magellanic Cloud. The FGS TRANS mode observations are sensitive to the detection of companions with an angular separation between 0.″01 and 1.″0 and brighter than △m=5. The FGS observations resolved 52 binary and 6 triple star systems and detected partially resolved binaries in 7 additional targets (43 of these are new detections). These numbers yield a companion detection frequency of 29% for the FGS survey. We also gathered literature results on the numbers of close spectroscopic binaries and wider astrometric binaries among the sample, and we present estimates of the frequency of multiple systems and the companion frequency for subsets of stars residing in clusters and associations, field stars, and runaway stars. These results confirm the high multiplicity fraction, especially among massive stars in clusters and associations. We show that the period distribution is approximately flat in increments of logP. We identify a number of systems of potential interest for long-term orbital determinations, and we note the importance of some of these companions for the interpretation of the radial velocities and light curves of close binaries that have third companions.

  2. Q-ball imaging models: comparison between high and low angular resolution diffusion-weighted MRI protocols for investigation of brain white matter integrity

    Energy Technology Data Exchange (ETDEWEB)

    Caiazzo, Giuseppina; Trojsi, Francesca; Cirillo, Mario; Tedeschi, Gioacchino [MRI Research Center SUN-FISM-Neurological Institute for Diagnosis and Care ' ' Hermitage Capodimonte' ' , Naples (Italy); Second University of Naples, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Naples (Italy); Esposito, Fabrizio [University of Salerno, Department of Medicine and Surgery, Baronissi (Salerno) (Italy); Maastricht University, Department of Cognitive Neuroscience, Maastricht (Netherlands)

    2016-02-15

    Q-ball imaging (QBI) is one of the typical data models for quantifying white matter (WM) anisotropy in diffusion-weighted MRI (DwMRI) studies. Brain and spinal investigation by high angular resolution DwMRI (high angular resolution imaging (HARDI)) protocols exhibits higher angular resolution in diffusion imaging compared to low angular resolution models, although with longer acquisition times. We aimed to assess the difference between QBI-derived anisotropy values from high and low angular resolution DwMRI protocols and their potential advantages or shortcomings in neuroradiology. Brain DwMRI data sets were acquired in seven healthy volunteers using both HARDI (b = 3000 s/mm{sup 2}, 54 gradient directions) and low angular resolution (b = 1000 s/mm{sup 2}, 32 gradient directions) acquisition schemes. For both sequences, tract of interest tractography and generalized fractional anisotropy (GFA) measures were extracted by using QBI model and were compared between the two data sets. QBI tractography and voxel-wise analyses showed that some WM tracts, such as corpus callosum, inferior longitudinal, and uncinate fasciculi, were reconstructed as one-dominant-direction fiber bundles with both acquisition schemes. In these WM tracts, mean percent different difference in GFA between the two data sets was less than 5 %. Contrariwise, multidirectional fiber bundles, such as corticospinal tract and superior longitudinal fasciculus, were more accurately depicted by HARDI acquisition scheme. Our results suggest that the design of optimal DwMRI acquisition protocols for clinical investigation of WM anisotropy by QBI models should consider the specific brain target regions to be explored, inducing researchers to a trade-off choice between angular resolution and acquisition time. (orig.)

  3. A study of the red supergiant Betelgeuse at high angular resolution

    Science.gov (United States)

    Montargès, M.; Kervella, P.; Perrin, G.; Ohnaka, K.

    2013-11-01

    Betelgeuse (α Ori) is a M2Iab star, prototype for the red supergiant class. These stars contributes to the chemical enrichment of the interstellar medium (ISM) through their heavy mass loss and thanks to the IIP type supernova of whom they are the progenitors. With its proximity (˜ 130 pc) and thus of its large apparent diameter (˜ 42 mas), Betelgeuse is a good candidate for a detailed study of the atmosphere of a red supergiant Our analysis of VLTI/AMBER data allowed to characterize the close environment of the star: its molecular envelope (MOLsphere). Using a thin layer model at le Local Thermodynamical Equilibrium (LTE), we obtained its angular diameter, temperature as well as the column densities for water vapor and carbon monoxide (CO). For the K band continuum, we reconstructed a one dimension image (profile) and we quantified the inhomogeneities of the photosphere.

  4. Stability of dislocation structures in copper towards stress relaxation investigated by high angular resolution 3D X-ray diffraction

    DEFF Research Database (Denmark)

    Jakobsen, Bo; Poulsen, Henning Friis; Lienert, Ulrich

    2009-01-01

    A 300 µm thick tensile specimen of OFHC copper is subjected to a tensile loading sequence and deformed to a maximal strain of 3.11%. Using the novel three-dimensional X-ray diffraction method High angular resolution 3DXRD', the evolution of the microstructure within a deeply embedded grain...... is characterised in-situ by the behaviour of individual subgrains. The loading sequence consists of three continuous deformation stages with strain rates of 1.1 × 10-6 s-1 and 3 × 10-2 s-1, in each case followed by a period of extended stress relaxation at fixed motor positions, as well as an unloading step...

  5. Probing region-specific microstructure of human cortical areas using high angular and spatial resolution diffusion MRI.

    Science.gov (United States)

    Aggarwal, Manisha; Nauen, David W; Troncoso, Juan C; Mori, Susumu

    2015-01-15

    Regional heterogeneity in cortical cyto- and myeloarchitecture forms the structural basis of mapping of cortical areas in the human brain. In this study, we investigate the potential of diffusion MRI to probe the microstructure of cortical gray matter and its region-specific heterogeneity across cortical areas in the fixed human brain. High angular resolution diffusion imaging (HARDI) data at an isotropic resolution of 92-μm and 30 diffusion-encoding directions were acquired using a 3D diffusion-weighted gradient-and-spin-echo sequence, from prefrontal (Brodmann area 9), primary motor (area 4), primary somatosensory (area 3b), and primary visual (area 17) cortical specimens (n=3 each) from three human subjects. Further, the diffusion MR findings in these cortical areas were compared with histological silver impregnation of the same specimens, in order to investigate the underlying architectonic features that constitute the microstructural basis of diffusion-driven contrasts in cortical gray matter. Our data reveal distinct and region-specific diffusion MR contrasts across the studied areas, allowing delineation of intracortical bands of tangential fibers in specific layers-layer I, layer VI, and the inner and outer bands of Baillarger. The findings of this work demonstrate unique sensitivity of diffusion MRI to differentiate region-specific cortical microstructure in the human brain, and will be useful for myeloarchitectonic mapping of cortical areas as well as to achieve an understanding of the basis of diffusion NMR contrasts in cortical gray matter. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Optics Developments for X-Ray Astronomy

    Science.gov (United States)

    Ramsey, Brian

    2014-01-01

    X-ray optics has revolutionized x-ray astronomy. The degree of background suppression that these afford, have led to a tremendous increase in sensitivity. The current Chandra observatory has the same collecting area (approx. 10(exp 3)sq cm) as the non-imaging UHURU observatory, the first x-ray observatory which launched in 1970, but has 5 orders of magnitude more sensitivity due to its focusing optics. In addition, its 0.5 arcsec angular resolution has revealed a wealth of structure in many cosmic x-ray sources. The Chandra observatory achieved its resolution by using relatively thick pieces of Zerodur glass, which were meticulously figured and polished to form the four-shell nested array. The resulting optical assembly weighed around 1600 kg, and cost approximately $0.5B. The challenge for future x-ray astronomy missions is to greatly increase the collecting area (by one or more orders of magnitude) while maintaining high angular resolution, and all within realistic mass and budget constraints. A review of the current status of US optics for x-ray astronomy will be provided along with the challenges for future developments.

  7. Probe diagnostics of electron distributions in plasma with spatial and angular resolution

    Energy Technology Data Exchange (ETDEWEB)

    Demidov, V. I.; Kudryavtsev, A. A. [St. Petersburg State University, St. Petersburg 199034, Russia and ITMO University, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation)

    2014-09-15

    This paper discusses the spatial resolution that is required to study inhomogeneous, low-temperature plasmas and is based on a review of low-temperature plasma electron kinetics and methods for probe measurements of electron energy distribution functions (EEDFs). It is stated that EEDFs can be extracted from probe measurements by applying an appropriate probe theory. The Druyvesteyn formula is most commonly used for this extraction and has been used in numerous publications, but more general theory can be used for a wider range of gas pressures. It is demonstrated that the Druyvesteyn formula can be obtained from the general theory as a limiting case. This paper justifies the application of wall probes in plasma studies of an energetic part of EEDFs. This justification is made for an idealized probe. We briefly review the methods for studying anisotropic plasmas and their usefulness in plasma research. It is demonstrated that to determine anisotropic electron energy distribution functions, a planar, one-sided probe is most convenient.

  8. Innovation in Astronomy Education

    Science.gov (United States)

    Pasachoff, Jay M.; Ros, Rosa M.; Pasachoff, Naomi

    2013-01-01

    large astronomical data holdings; Poster abstracts; Part IV. Practical Issues Connected with the Implementation of the 2003 IAU Resolution: Introduction; 33. Stellar evolution for students of Moscow University; 34. Astronomy for everybody: An approach from the CASAO/NAUH view; 35. Toward a new program in astronomy education in secondary schools in Turkey; 36. Universe awareness for young children; 37. Education in Egypt and Egyptian responses to eclipses; 38. Astronomy in the cultural heritage of African societies; 39. Education at the Pierre Auger Observatory: the cinema as a tool in science education; 40. Freshman seminars: interdisciplinary engagements in astronomy; 41. Astronomy for teachers; Poster abstracts; Conclusion.

  9. Selection of γ- and proton showers based on angular characteristics of Cherenkov radiation and estimation of angular resolution of the optical-telescope system

    International Nuclear Information System (INIS)

    Anokhina, A.M.; Galkin, V.I.; Ivanenko, I.P.; Roganova, T.M.

    1991-01-01

    Multidimensional criterion for isolation of showers from γ-quanta at the background of proton showers based on the angular shower image characteristics in an optical telescope with 3 deg x 3 deg field of vision, comprising 10x10 PEM, located in the focal plane of a spherical, mirror with the area of 5 m 2 , is described. Results of classification of artificial events using this criterion within 10 12 -10 14 eV primary energy range are presented. Evaluations of the accuracy of re-establishing the direction of γ quantum arrival are performed as well

  10. Fused silica segments: a possible solution for x-ray telescopes with very high angular resolution like Lynx/XRS

    Science.gov (United States)

    Salmaso, Bianca; Basso, Stefano; Civitani, Marta; Ghigo, Mauro; Hołyszko, Joanna; Spiga, Daniele; Vecchi, Gabriele; Pareschi, Giovanni

    2017-09-01

    In order to look beyond Chandra, the Lynx/XRS mission has been proposed in USA and is currently studied by NASA. The optic will have an effective area of 2.5 m2 and an angular resolution of 0.5 arcsec HEW at 1 keV. In order to fulfill these requirements different technologies are considered, with the approaches of both full and segmented shells (that, possibly, can be also combined together). Concerning the production of segmented mirrors, a variety of thin substrates (glass, metal, silicon) are envisaged, that can be produced using both direct polishing or replication methods. Innovative post-fabrication correction methods (such as piezoelectric or magneto-restrictive film actuators on the back surface, differential deposition, ion implantation) are being also considered in order to reach the final tolerances. In this paper we are presenting a technology development based on fused silica (SiO2) segmented substrates, owing the low coefficient of thermal expansion of Fused Silica and its high chemical stability compared to other glasses. Thin SiO2 segmented substrates (typically 2 mm thick) are figured by direct polishing combined with final profile ion figuring correction, while the roughness reduction is reached with pitch tools. For the profile and roughness correction, the segments are glued to a substrate. In this paper we present the current status of this technology.

  11. Improvement of the angular resolution of the Muon Tracking Detector in KASCADE and determination of muon production heights

    International Nuclear Information System (INIS)

    Obenland, R.

    2005-06-01

    The KASCADE-experiment investigates cosmic rays in the region of the knee. Because of the combined determination of the shower direction by the array and the direction of muons with the muon tracking detector, the muon production height in extended air showers can be analysed. Modifying the readout from two combined streamer tube cells to single wire readout, the determination of the direction of muons with an improved angular resolution was enabled. For that purpose, a separation of the combined wire signals was achieved by an adequate pulse shaping. The investigation of radial angles as well as muon production heights represents a direct study of the longitudinal shower development in the atmosphere. The comparison of measured data with simulations exhibit a systematic discrepancy. Two different explanations are possible. In one case the muons leave the shower axis in the simulations with a relatively low transverse momentum and in the other case the air showers develop relatively high in the atmosphere as compared to reality. Especially, the used hadronic interaction models have to be reconsidered. Systematic investigations exclude detector effects and geometric uncertainties. The use of correlated array parameters of muon and electron shower size allows a classification in air showers induced by light and heavy primary particles. The difference between light and heavy agrees with the difference between simulations with proton and iron. With the enriched data samples the sensitivity of the muon tracking detector via radial angle or muon production height to the mass of the primary particle could be confirmed. (orig.)

  12. Milliarcsecond Astronomy with the CHARA Array

    Science.gov (United States)

    Schaefer, Gail; ten Brummelaar, Theo; Gies, Douglas; Jones, Jeremy; Farrington, Christopher

    2018-01-01

    The Center for High Angular Resolution Astronomy offers 50 nights per year of open access time at the CHARA Array. The Array consists of six telescopes linked together as an interferometer, providing sub-milliarcsecond resolution in the optical and near-infrared. The Array enables a variety of scientific studies, including measuring stellar angular diameters, imaging stellar shapes and surface features, mapping the orbits of close binary companions, and resolving circumstellar environments. The open access time is part of an NSF/MSIP funded program to open the CHARA Array to the broader astronomical community. As part of the program, we will build a searchable database for the CHARA data archive and run a series of one-day community workshops at different locations across the country to expand the user base for stellar interferometry and encourage new scientific investigations with the CHARA Array.

  13. The dependence of bar frequency on galaxy mass, colour, and gas content - and angular resolution - in the local universe

    Science.gov (United States)

    Erwin, Peter

    2018-03-01

    I use distance- and mass-limited subsamples of the Spitzer Survey of Stellar Structure in Galaxies (S4G) to investigate how the presence of bars in spiral galaxies depends on mass, colour, and gas content and whether large, Sloan Digital Sky Survey (SDSS)-based investigations of bar frequencies agree with local data. Bar frequency reaches a maximum of fbar ≈ 0.70 at M⋆ ˜ 109.7M⊙, declining to both lower and higher masses. It is roughly constant over a wide range of colours (g - r ≈ 0.1-0.8) and atomic gas fractions (log (M_{H I}/ M_{\\star }) ≈ -2.5 to 1). Bars are thus as common in blue, gas-rich galaxies are they are in red, gas-poor galaxies. This is in sharp contrast to many SDSS-based studies of z ˜ 0.01-0.1 galaxies, which report fbar increasing strongly to higher masses (from M⋆ ˜ 1010 to 1011M⊙), redder colours, and lower gas fractions. The contradiction can be explained if SDSS-based studies preferentially miss bars in, and underestimate the bar fraction for, lower mass (bluer, gas-rich) galaxies due to poor spatial resolution and the correlation between bar size and stellar mass. Simulations of SDSS-style observations using the S4G galaxies as a parent sample, and assuming that bars below a threshold angular size of twice the point spread function full width at half-maximum cannot be identified, successfully reproduce typical SDSS fbar trends for stellar mass and gas mass ratio. Similar considerations may affect high-redshift studies, especially if bars grow in length over cosmic time; simulations suggest that high-redshift bar fractions may thus be systematically underestimated.

  14. Characterisation of radiation damage in perovskite using high angular resolution electron channeling x-ray spectroscopy (HARECXS)

    International Nuclear Information System (INIS)

    Smith, K.L.; Zaluzec, N.J.

    2002-01-01

    Full text: Predicting and/or modelling the occurrence of radiation damage induced defects and their effects on physical properties (eg. amorphisation induced swelling, electrical conductivity., optical response etc.) in ceramic phases requires knowledge of the displacement energies, E d , of cations and anions in those phases. In this study, High Angular Resolution Electron Channelling X-ray Spectroscopy (HARECXS) spectra were collected from perovskite (CaTiO 3 ) samples that had been exposed to high-energy electrons or high-energy heavy ions. Calculations based on experimental data were then used to indicate the E d of the cations in perovskite. The HARECXS measurements were conducted on a Philips EM 420T AEM (LaB6 source, operated at 120 kV) fitted with an EDAX ultra thin window Si(Li) detector. The specimen was first manually oriented to an appropriate zone axis. Then control of the relative orientation of the incident probe was accomplished via direct computer control of the beam tilt coils, Typical acquisition times for a complete two-dimensional scan were 18-24 hours, while one dimensional scans ranged from 1-5 hours. Our experiments established that: a) HARECXS can detect radiation damage in perovskite caused by either high energy heavy ions or high energy electrons, b) the HARECXS signature of perovskite shows a systematic change with ion dose, c) HARECXS detects damage in perovskite that has been irradiated with 900kV electrons and does not detect damage in perovskite that has been irradiated with 620kV electrons, indicating the existance of an electron irradiation damage threshold. Calculations based on the latter results indicate that the displacement energy, E d of calcium and titanium in perovskite lie between 50 and 85eV. Copyright (2002) Australian Society for Electron Microscopy Inc

  15. A super-high angular resolution principle for coded-mask X-ray imaging beyond the diffraction limit of a single pinhole

    International Nuclear Information System (INIS)

    Zhang Chen; Zhang Shuangnan

    2009-01-01

    High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffraction-interference effect was thought to degrade coded-mask imaging performance dramatically at the low energy end with its very long mask-detector distance. The diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method (DICC) is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle (SHARP) for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of a single pinhole is demonstrated with simulations. With the specification that the mask element size is 50 x 50 μm 2 and the mask-detector distance is 50 m, the achieved angular resolution is 0.32 arcsec above about 10 keV and 0.36 arcsec at 1.24 keV (λ = 1 nm), where diffraction cannot be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also briefly discussed. (invited reviews)

  16. KiwiSpec: The Design and Performance of a High Resolution Echelle Spectrograph for Astronomy

    Science.gov (United States)

    Gibson, Steven Ross

    This document describes the design, analysis, construction and testing of KiwiSpec, a fibre-fed, high resolution astronomical spectrograph of an asymmetric white pupil design. The instrument employs an R4, 31.6 groove mm-1 échelle grating for primary dispersion and a 725 lines mm-1 volume phase holographic (VPH) based grism for cross-dispersion. Two versions of the prototype were designed and constructed: an 'in-air' prototype, and a prototype featuring a vacuum chamber (to increase the stability of the instrument). The KiwiSpec optical design is introduced, as well as a description of the theory behind a cross-dispersed échelle spectrograph. The results of tolerancing the optical design are reported for alignment, optical fabrication, and optical surface quality groups of parameters. The optical windows of an iodine cell are also toleranced. The opto-mechanical mounts of both prototypes are described in detail, as is the design of the vacuum chamber system. Given the goal of 1 m/s radial velocity stability, analyses were undertaken to determine the allowable amount of movement of the vacuum windows, and to determine the allowable changes in temperature and pressure within and outside of the vacuum chamber. The spectral efficiency of the instrument was estimated through a predictive model; this was calculated for the as-built instrument and also for an instrument with ideal, high-efficiency coatings. Measurements of the spectral efficiency of various components of the instrument are reported, as well as a description of the measurement system developed to test the efficiency of VPH gratings. On-sky efficiency measurements from use of KiwiSpec on the 1-m McLellan telescope at Mt John University Observatory are reported. Two possible exposure meter locations are explored via an efficiency model, and also through the measurement of the zero-order reflectivity of the échelle grating. Various stability aspects of the design are investigated. These include the

  17. Radio astronomy and spectrum management - The impact of WARC-79

    International Nuclear Information System (INIS)

    Pankonin, V.; Price, R.M.

    1981-01-01

    The characteristics of radio astronomy are considered, taking into account broad-band and narrow-band cosmic radiation, the evolution of equipment and techniques of the radio astronomer toward better sensitivity and better angular resolution, and the three general classes into which radio telescopes can be divided. Attention is given to the extraordinary interference problems faced by radio astronomers, the location of radio-astronomy observatories in secluded locations, the preparation by radio astronomers and space scientists for WARC-79, the actions taken at WARC-79, and the WARC impact. It is pointed out that radio astronomy has emerged from WARC-79 in a better position in the International Radio Regulations than it has ever enjoyed in the past. Radio astronomers can be satisfied that the requirements of their radio service are generally being given serious consideration. Most of the requests for allocations have been granted at frequencies above 20 GHz

  18. Galactic Astronomy in the Ultraviolet

    Science.gov (United States)

    Rastorguev, A. S.; Sachkov, M. E.; Zabolotskikh, M. V.

    2017-12-01

    We propose a number of prospective observational programs for the ultraviolet space observatory WSO-UV, which seem to be of great importance to modern galactic astronomy. The programs include the search for binary Cepheids; the search and detailed photometric study and the analysis of radial distribution of UV-bright stars in globular clusters ("blue stragglers", blue horizontal-branch stars, RR Lyrae variables, white dwarfs, and stars with UV excesses); the investigation of stellar content and kinematics of young open clusters and associations; the study of spectral energy distribution in hot stars, including calculation of the extinction curves in the UV, optical and NIR; and accurate definition of the relations between the UV-colors and effective temperature. The high angular resolution of the observatory allows accurate astrometric measurements of stellar proper motions and their kinematic analysis.

  19. H.E.S.S. observations of RX J1713.7-3946 with improved angular and spectral resolution: Evidence for gamma-ray emission extending beyond the X-ray emitting shell

    Science.gov (United States)

    H.E.S.S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.'C.; Dubus, G.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Fukuyama, T.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hadasch, D.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Öttl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Volpe, F.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.

    2018-04-01

    Supernova remnants exhibit shock fronts (shells) that can accelerate charged particles up to very high energies. In the past decade, measurements of a handful of shell-type supernova remnants in very high-energy gamma rays have provided unique insights into the acceleration process. Among those objects, RX J1713.7-3946 (also known as G347.3-0.5) has the largest surface brightness, allowing us in the past to perform the most comprehensive study of morphology and spatially resolved spectra of any such very high-energy gamma-ray source. Here we present extensive new H.E.S.S. measurements of RX J1713.7-3946, almost doubling the observation time compared to our previous publication. Combined with new improved analysis tools, the previous sensitivity is more than doubled. The H.E.S.S. angular resolution of 0.048° (0.036° above 2 TeV) is unprecedented in gamma-ray astronomy and probes physical scales of 0.8 (0.6) parsec at the remnant's location. The new H.E.S.S. image of RX J1713.7-3946 allows us to reveal clear morphological differences between X-rays and gamma rays. In particular, for the outer edge of the brightest shell region, we find the first ever indication for particles in the process of leaving the acceleration shock region. By studying the broadband energy spectrum, we furthermore extract properties of the parent particle populations, providing new input to the discussion of the leptonic or hadronic nature of the gamma-ray emission mechanism. All images (FITS files) are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A6

  20. High-resolution size measurement of single spherical particles with a fast Fourier transform of the angular scattering intensity.

    Science.gov (United States)

    Min, S L; Gomez, A

    1996-08-20

    A technique is described and demonstrated to measure the size of spherical particles of known index of refraction by laser light scattering with an accuracy of better than 1%. This technique entails imaging the angular scattering intensity onto a photodiode array and applying a fast Fourier transform to the array output to obtain a frequency and phase corresponding to the number and angular position of the scattering lobes. Errors associated with particle trajectory effects and changes in the index of refraction are also considered. Results are not affected by the former, whereas variations of the refractive index by 2%, as may be typical, for example, of the transient heat up of a liquid hydrocarbon droplet, cause a deterioration of sizing accuracy to approximately 3%. The technique can in principle be applied in real time at data rates as high as 20-30 kHz with a modest equipment investment. Therefore, the measurement of droplet evaporation rates in dilute sprays with unprecedented accuracy appears to be feasible.

  1. Ground-based gamma-ray astronomy with Cherenkov telescopes

    International Nuclear Information System (INIS)

    Hinton, Jim

    2009-01-01

    Very high-energy (>100 GeV) γ-ray astronomy is emerging as an important discipline in both high-energy astrophysics and astro-particle physics. This field is currently dominated by imaging atmospheric-Cherenkov telescopes (IACTs) and arrays of these telescopes. Such arrays have achieved the best angular resolution and energy flux sensitivity in the γ-ray domain and are still far from the fundamental limits of the technique. Here, I will summarize some key aspects of this technique and go on to review the current status of the major instruments and to highlight selected recent results.

  2. Optic radiation fiber tractography in glioma patients based on high angular resolution diffusion imaging with compressed sensing compared with diffusion tensor imaging - initial experience.

    Directory of Open Access Journals (Sweden)

    Daniela Kuhnt

    Full Text Available OBJECTIVE: Up to now, fiber tractography in the clinical routine is mostly based on diffusion tensor imaging (DTI. However, there are known drawbacks in the resolution of crossing or kissing fibers and in the vicinity of a tumor or edema. These restrictions can be overcome by tractography based on High Angular Resolution Diffusion Imaging (HARDI which in turn requires larger numbers of gradients resulting in longer acquisition times. Using compressed sensing (CS techniques, HARDI signals can be obtained by using less non-collinear diffusion gradients, thus enabling the use of HARDI-based fiber tractography in the clinical routine. METHODS: Eight patients with gliomas in the temporal lobe, in proximity to the optic radiation (OR, underwent 3T MRI including a diffusion-weighted dataset with 30 gradient directions. Fiber tractography of the OR using a deterministic streamline algorithm based on DTI was compared to tractography based on reconstructed diffusion signals using HARDI+CS. RESULTS: HARDI+CS based tractography displayed the OR more conclusively compared to the DTI-based results in all eight cases. In particular, the potential of HARDI+CS-based tractography was observed for cases of high grade gliomas with significant peritumoral edema, larger tumor size or closer proximity of tumor and reconstructed fiber tract. CONCLUSIONS: Overcoming the problem of long acquisition times, HARDI+CS seems to be a promising basis for fiber tractography of the OR in regions of disturbed diffusion, areas of high interest in glioma surgery.

  3. Adaptive Optics, LLLFT Interferometry, Astronomy

    National Research Council Canada - National Science Library

    2002-01-01

    We propose to build a three telescope Michelson optical interferometer equipped with wavefront compensation technology as a demonstration and test bed for high resolution Deep Space Surveillance (DSS) and Astronomy...

  4. High-resolution mapping reveals linkage between genes in common bean cultivar Ouro Negro conferring resistance to the rust, anthracnose, and angular leaf spot diseases.

    Science.gov (United States)

    Valentini, Giseli; Gonçalves-Vidigal, Maria Celeste; Hurtado-Gonzales, Oscar P; de Lima Castro, Sandra Aparecida; Cregan, Perry B; Song, Qijian; Pastor-Corrales, Marcial A

    2017-08-01

    Co-segregation analysis and high-throughput genotyping using SNP, SSR, and KASP markers demonstrated genetic linkage between Ur-14 and Co-3 4 /Phg-3 loci conferring resistance to the rust, anthracnose and angular leaf spot diseases of common bean. Rust, anthracnose, and angular leaf spot are major diseases of common bean in the Americas and Africa. The cultivar Ouro Negro has the Ur-14 gene that confers broad spectrum resistance to rust and the gene cluster Co-3 4 /Phg-3 containing two tightly linked genes conferring resistance to anthracnose and angular leaf spot, respectively. We used co-segregation analysis and high-throughput genotyping of 179 F 2:3 families from the Rudá (susceptible) × Ouro Negro (resistant) cross-phenotyped separately with races of the rust and anthracnose pathogens. The results confirmed that Ur-14 and Co-3 4 /Phg-3 cluster in Ouro Negro conferred resistance to rust and anthracnose, respectively, and that Ur-14 and the Co-3 4 /Phg-3 cluster were closely linked. Genotyping the F 2:3 families, first with 5398 SNPs on the Illumina BeadChip BARCBEAN6K_3 and with 15 SSR, and eight KASP markers, specifically designed for the candidate region containing Ur-14 and Co-3 4 /Phg-3, permitted the creation of a high-resolution genetic linkage map which revealed that Ur-14 was positioned at 2.2 cM from Co-3 4 /Phg-3 on the short arm of chromosome Pv04 of the common bean genome. Five flanking SSR markers were tightly linked at 0.1 and 0.2 cM from Ur-14, and two flanking KASP markers were tightly linked at 0.1 and 0.3 cM from Co-3 4 /Phg-3. Many other SSR, SNP, and KASP markers were also linked to these genes. These markers will be useful for the development of common bean cultivars combining the important Ur-14 and Co-3 4 /Phg-3 genes conferring resistance to three of the most destructive diseases of common bean.

  5. High Resolution Infrared Spectroscopy in Astronomy Proceedings of an ESO Workshop Held at Garching, Germany, 18-21 November 2003

    CERN Document Server

    Käufl, Hans Ulrich; Moorwood, Alan F. M

    2005-01-01

    Two specialized new instruments for ESO's VLT, VISIR and CRIRES, spawned the idea for this workshop. CRIRES is a dedicated very high resolution infrared spectrograph; VISIR features a high resolution spectroscopic mode. Together, the instruments combine the sensitivity of an 8m-telescope with the now well-established reliability of VLT-facility instruments. High resolution here means that lines in cool stellar atmospheres and HII-regions can be resolved. The astrophysical topics discussed in this rather specialized workshop range from the inner solar system to active galactic nuclei. There are many possibilities for new discoveries with these instruments, but the unique capability, which becomes available through high-resolution infrared spectroscopy, is the observation of molecular rotational-vibrational transitions in many astrophysical environments. Particularly interesting and surprising in this context, many papers on modeling and laboratory spectroscopy at the workshop appear to indicate that astronomic...

  6. New imaging spectrometer CdTe very high spatial and spectral resolution for X and gamma astronomy

    International Nuclear Information System (INIS)

    Dubos, Sebastien

    2015-01-01

    The thesis work presented in this manuscript corresponds to the first development phase of the MC2 project, an ambitious R and D effort to realize a new type of cadmium telluride (CdTe) -based imaging spectrometer for future hard X- and gamma-rays astronomy missions. The final goal is to achieve a 300 micron-pitch pixelated detector plane hybridized with a very low noise front-end electronics for a total pixel density multiplied by 4 compared to the most advanced System recently available in the laboratory, the Caliste HD imaging spectrometer. Moreover, thanks to the joint development of readout circuits adapted to the interconnection of pixelated detectors with low capacitance and low leakage current, spectroscopic performances of such system are assumed to approach inherent limitations of the CdTe detector, especially for the lowest energies. The work was organized in parallel and complementary areas: evaluation of current Systems, feedback and identification of issues associated with the development of highly-resolved detection planes, implementation and complete characterization of a new two-dimensional ASIC specifically developed for this application, and modeling and study of the associated sensor to optimize the design of the detector pattern. Finally, a first hybrid prototype was completed and first experimental tests thereby conducted. (author) [fr

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

    Science.gov (United States)

    Rinehart, Stephen

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

  8. Infrared spectroscopy in astronomy

    Science.gov (United States)

    Houck, J. R.

    1981-01-01

    The use of infrared spectroscopy in astronomy has increased dramatically in the past ten years. The broad design considerations are discussed in terms of wavelength coverage and resolution. Three rough resolution ranges, lambda/Delta lambda of approximately 100, 1000 and 10,000, are identified in which various types of astronomical problems can be studied. Numerous existing systems are briefly discussed and references are given to more complete descriptions.

  9. Greek astronomy

    CERN Document Server

    Heath, Sir Thomas L

    2011-01-01

    Astronomy as a science began with the Ionian philosophers, with whom Greek philosophy and mathematics also began. While the Egyptians and Babylonians had accomplished much of astronomical worth, it remained for the unrivalled speculative genius of the Greeks, in particular, their mathematical genius, to lay the foundations of the true science of astronomy. In this classic study, a noted scholar discusses in lucid detail the specific advances made by the Greeks, many of whose ideas anticipated the discoveries of modern astronomy.Pythagoras, born at Samos about 572 B.C., was probably the first

  10. Angular Momentum

    Science.gov (United States)

    Shakur, Asif; Sinatra, Taylor

    2013-01-01

    The gyroscope in a smartphone was employed in a physics laboratory setting to verify the conservation of angular momentum and the nonconservation of rotational kinetic energy. As is well-known, smartphones are ubiquitous on college campuses. These devices have a panoply of built-in sensors. This creates a unique opportunity for a new paradigm in…

  11. Design and Fabrication of Two-Dimensional Semiconducting Bolometer Arrays for the High Resolution Airborne Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II (SHARC-II)

    Science.gov (United States)

    Voellmer, George M.; Allen, Christine A.; Amato, Michael J.; Babu, Sachidananda R.; Bartels, Arlin E.; Benford, Dominic J.; Derro, Rebecca J.; Dowell, C. Darren; Harper, D. Al; Jhabvala, Murzy D.

    2002-01-01

    The High resolution Airborne Wideband Camera (HAWC) and the Submillimeter High Angular Resolution Camera II (SHARC II) will use almost identical versions of an ion-implanted silicon bolometer array developed at the National Aeronautics and Space Administration's Goddard Space Flight Center (GSFC). The GSFC 'Pop-up' Detectors (PUD's) use a unique folding technique to enable a 12 x 32-element close-packed array of bolometers with a filling factor greater than 95 percent. A kinematic Kevlar(trademark) suspension system isolates the 200 mK bolometers from the helium bath temperature, and GSFC - developed silicon bridge chips make electrical connection to the bolometers, while maintaining thermal isolation. The JFET preamps operate at 120 K. Providing good thermal heat sinking for these, and keeping their conduction and radiation from reaching the nearby bolometers, is one of the principal design challenges encountered. Another interesting challenge is the preparation of the silicon bolometers. They are manufactured in 32-element, planar rows using Micro Electro Mechanical Systems (MEMS) semiconductor etching techniques, and then cut and folded onto a ceramic bar. Optical alignment using specialized jigs ensures their uniformity and correct placement. The rows are then stacked to create the 12 x 32-element array. Engineering results from the first light run of SHARC II at the Caltech Submillimeter Observatory (CSO) are presented.

  12. Fundamental Astronomy

    CERN Document Server

    Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan

    2007-01-01

    Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.

  13. Radio astronomy

    International Nuclear Information System (INIS)

    Parijskij, Y.N.; Gossachinskij, I.V.; Zuckerman, B.; Khersonsky, V.K.; Pustilnik, S.; Robinson, B.J.

    1976-01-01

    A critical review of major developments and discoveries in the field of radioastronomy during the period 1973-1975 is presented. The report is presented under the following headings:(1) Continuum radiation from the Galaxy; (2) Neutral hydrogen, 21 cm (galactic and extragalactic) and recombination lines; (3) Radioastronomy investigations of interstellar molecules; (4) Extragalactic radio astronomy and (6) Development in radio astronomy instruments. (B.R.H.)

  14. Discovering astronomy

    Science.gov (United States)

    Chapman, R. D.

    1978-01-01

    An overview of basic astronomical knowledge is presented with attention to the structure and dynamics of the stars and planets. Also dealt with are techniques of astronomical measurement, e.g., stellar spectrometry, radio astronomy, star catalogs, etc. Basic physical principles as they pertain to astronomy are reviewed, including the nature of light, gravitation, and electromagnetism. Finally, stellar evolution and cosmology are discussed with reference to the possibility of life elsewhere in the universe.

  15. Astronomy Communication

    Science.gov (United States)

    Heck, A.; Madsen, C.

    2003-07-01

    Astronomers communicate all the time, with colleagues of course, but also with managers and administrators, with decision makers and takers, with social representatives, with the news media, and with the society at large. Education is naturally part of the process. Astronomy communication must take into account several specificities: the astronomy community is rather compact and well organized world-wide; astronomy has penetrated the general public remarkably well with an extensive network of associations and organizations of aficionados all over the world. Also, as a result of the huge amount of data accumulated and by necessity for their extensive international collaborations, astronomers have pioneered the development of distributed resources, electronic communications and networks coupled to advanced methodologies and technologies, often much before they become of common world-wide usage. This book is filling up a gap in the astronomy-related literature by providing a set of chapters not only of direct interest to astronomy communication, but also well beyond it. 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 communication techniques while providing specific detailed information, as well as plenty of pointers and bibliographic elements. This book will be very useful for researchers, teachers, editors, publishers, librarians, computer scientists, sociologists of science, research planners and strategists, project managers, public-relations officers, plus those in charge of astronomy-related organizations, as well as for students aiming at a career in astronomy or related space science. Link: http://www.wkap.nl/prod/b/1-4020-1345-0

  16. GALACTICNUCLEUS: A high angular resolution JHKs imaging survey of the Galactic centre. I. Methodology, performance, and near-infrared extinction towards the Galactic centre

    Science.gov (United States)

    Nogueras-Lara, F.; Gallego-Calvente, A. T.; Dong, H.; Gallego-Cano, E.; Girard, J. H. V.; Hilker, M.; de Zeeuw, P. T.; Feldmeier-Krause, A.; Nishiyama, S.; Najarro, F.; Neumayer, N.; Schödel, R.

    2018-03-01

    Context. The Galactic centre (GC) is of fundamental astrophysical interest, but existing near-infrared surveys fall short covering it adequately, either in terms of angular resolution, multi-wavelength coverage, or both. Here we introduce the GALACTICNUCLEUS survey, a JHKs imaging survey of the centre of the Milky Way with a 0.2″ angular resolution. Aim. The purpose of this paper is to present the observations of Field 1 of our survey, centred approximately on SgrA* with an approximate size of 7.95' × 3.43'. We describe the observational set-up and data reduction pipeline and discuss the quality of the data. Finally, we present the analysis of the data. Methods: The data were acquired with the near-infrared camera High Acuity Wide field K-band Imager (HAWK-I) at the ESO Very Large Telescope (VLT). Short readout times in combination with the speckle holography algorithm allowed us to produce final images with a stable, Gaussian PSF (point spread function) of 0.2″ FWHM (full width at half maximum). Astrometric calibration is achieved via the VISTA Variables in the Via Lactea (VVV) survey and photometric calibration is based on the SIRIUS/Infrared Survey Facility telescope (IRSF) survey. The quality of the data is assessed by comparison between observations of the same field with different detectors of HAWK-I and at different times. Results: We reach 5σ detection limits of approximately J = 22, H = 21, and Ks = 20. The photometric uncertainties are less than 0.05 at J ≲ 20, H ≲ 17, and Ks ≲ 16. We can distinguish five stellar populations in the colour-magnitude diagrams; three of them appear to belong to foreground spiral arms, and the other two correspond to high- and low-extinction star groups at the GC. We use our data to analyse the near-infrared extinction curve and find some evidence for a possible difference between the extinction index between J - H and H - Ks. However, we conclude that it can be described very well by a power law with an index of

  17. A hybrid concept (segmented plus monolithic fused silica shells) for a high-throughput and high-angular resolution x-ray mission (Lynx/X-Ray Surveyor like)

    Science.gov (United States)

    Basso, Stefano; Civitani, Marta; Pareschi, Giovanni; Parodi, Giancarlo

    2017-09-01

    Lynx is a large area and high angular resolution X-ray mission being studied by NASA to be presented to the next Decadal Survey for the implementation in the next decade. It aims to realize an X-ray telescope with the effective area similar to Athena (2 m2 at 1 keV) but with the same angular resolution of Chandra and a much larger Field Of View (up 20 arcmin x 20 arcmin). The science of X-ray Surveyor requires a large-throughput mirror assembly with sub-arcsec angular resolution. These future X-ray mirrors have a set of requirements which, collectively, represents very substantial advances over any currently in operation or planned for missions other than X-ray Surveyor. Of particular importance is achieving low mass per unit collecting area, while maintaining Chandra like angular resolution. Among the possible solutions under study, the direct polishing of both thin monolithic pseudo-cylindrical shells and segments made of fused silica are being considered as viable solutions for the implementation of the mirrors. Fused silica has very good thermomechanical parameters (including a very low CTE), making the material particularly well suited for for the production of the Lynx mirrors. It should be noted that the use of close shells is also very attractive, since the operations for the integration of the shells will be greatly simplified and the area lost due to the vignetting from the interfacing structures minimized even if the management of such big (diameter of 3 m) and thin shells have to be demonstrated. In this paper we will discuss a possible basic layout for a full shell mirror and a hybrid concept (segmented plus monolithic shells made of fused silica) as a second solution, for the Lynx/XRS telescope, discussing preliminary results in terms of optical and mechanical performance.

  18. Astronomy Explained

    Science.gov (United States)

    North, Gerald

    Every year large numbers of people take up the study of astronomy, mostly at amateur level. There are plenty of elementary books on the market, full of colourful photographs, but lacking in proper explanations of how and why things are as they are. Many people eventually wish to go beyond the 'coffee-table book' stage and study this fascinating subject in greater depth. This book is written for them. In addition, many people sit for public examinations in this subject each year and this book is also intended to be of use to them. All the topics from the GCSE syllabus are covered here, with sample questions at the end of each chapter. Astronomy Explained provides a comprehensive treatment of the subject in more depth than is usually found in elementary works, and will be of interest to both amateur astronomers and students of astronomy.

  19. Angular-domain scattering interferometry.

    Science.gov (United States)

    Shipp, Dustin W; Qian, Ruobing; Berger, Andrew J

    2013-11-15

    We present an angular-scattering optical method that is capable of measuring the mean size of scatterers in static ensembles within a field of view less than 20 μm in diameter. Using interferometry, the method overcomes the inability of intensity-based models to tolerate the large speckle grains associated with such small illumination areas. By first estimating each scatterer's location, the method can model between-scatterer interference as well as traditional single-particle Mie scattering. Direct angular-domain measurements provide finer angular resolution than digitally transformed image-plane recordings. This increases sensitivity to size-dependent scattering features, enabling more robust size estimates. The sensitivity of these angular-scattering measurements to various sizes of polystyrene beads is demonstrated. Interferometry also allows recovery of the full complex scattered field, including a size-dependent phase profile in the angular-scattering pattern.

  20. Astronomy essentials

    CERN Document Server

    Brass, Charles O

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Astronomy includes the historical perspective of astronomy, sky basics and the celestial coordinate systems, a model and the origin of the solar system, the sun, the planets, Kepler'

  1. Improvement in White Matter Tract Reconstruction with Constrained Spherical Deconvolution and Track Density Mapping in Low Angular Resolution Data: A Pediatric Study and Literature Review

    Directory of Open Access Journals (Sweden)

    Benedetta Toselli

    2017-08-01

    Full Text Available IntroductionDiffusion-weighted magnetic resonance imaging (DW-MRI allows noninvasive investigation of brain structure in vivo. Diffusion tensor imaging (DTI is a frequently used application of DW-MRI that assumes a single main diffusion direction per voxel, and is therefore not well suited for reconstructing crossing fiber tracts. Among the solutions developed to overcome this problem, constrained spherical deconvolution with probabilistic tractography (CSD-PT has provided superior quality results in clinical settings on adult subjects; however, it requires particular acquisition parameters and long sequences, which may limit clinical usage in the pediatric age group. The aim of this work was to compare the results of DTI with those of track density imaging (TDI maps and CSD-PT on data from neonates and children, acquired with low angular resolution and low b-value diffusion sequences commonly used in pediatric clinical MRI examinations.Materials and methodsWe analyzed DW-MRI studies of 50 children (eight neonates aged 3–28 days, 20 infants aged 1–8 months, and 22 children aged 2–17 years acquired on a 1.5 T Philips scanner using 34 gradient directions and a b-value of 1,000 s/mm2. Other sequence parameters included 60 axial slices; acquisition matrix, 128 × 128; average scan time, 5:34 min; voxel size, 1.75 mm × 1.75 mm × 2 mm; one b = 0 image. For each subject, we computed principal eigenvector (EV maps and directionally encoded color TDI maps (DEC-TDI maps from whole-brain tractograms obtained with CSD-PT; the cerebellar-thalamic, corticopontocerebellar, and corticospinal tracts were reconstructed using both CSD-PT and DTI. Results were compared by two neuroradiologists using a 5-point qualitative score.ResultsThe DEC-TDI maps obtained presented higher anatomical detail than EV maps, as assessed by visual inspection. In all subjects, white matter (WM tracts were successfully reconstructed using both

  2. Large Area and High Efficiency Photon Counting Imaging Detectors with High Time and Spatial Resolution for Night Time Sensing and Astronomy

    Science.gov (United States)

    Siegmund, O.; Vallerga, J.; Tremsin, A.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

    2012-09-01

    The development of large area photon counting, imaging, timing detectors with high performance has significance for applications in astronomy (such as our sensor on the SAAO SALT 10m telescope), night time remote reconnaissance, airborne/space situational awareness, and high-speed adaptive optics. Sealed tube configurations for optical/IR sensing also have applications in detection of Cherenkov light (RICH), biological single-molecule fluorescence lifetime imaging microscopy and neutron imaging applications. In open faced configurations these devices are important for UV and particle detection in space astrophysics, mass spectroscopy and many time-of flight applications. Currently available devices are limited to sizes of about 5 cm and use either conventional microchannel plates, or dynode multipliers for amplification, coupled coarse pad array readouts. Extension of these schemes to devices as large as 20 cm with high spatial resolution presents significant problems and potentially considerable cost. A collaboration (Large Area Picosecond Photon Detector) of the U. Chicago, Argonne National Laboratory, U.C. Berkeley, U. Hawaii and a number of other institutions has developed novel technologies to realize 20 cm format detectors in open face or sealed tube configurations. One critical component of this development is novel microchannel plates employing borosilicate micro-capillary arrays. The microchannel plates are based on a novel concept where the substrate is constructed from a borosilicate micro-capillary array that is made to function as a microchannel plate by deposition of resistive and secondary emissive layers using atomic layer deposition. The process is relatively inexpensive compared with conventional microchannel plates and allows very large microchannel plates to be produced with pore sizes as small as 10 microns. These provide many performance characteristics typical of conventional microchannel plates, but have been made in sizes up to 20 cm, have

  3. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Samir Choudhuri. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 35 Review. Prospects of Measuring the Angular Power Spectrum of the Diffuse Galactic Synchrotron Emission with SKA1 Low · Sk. Saiyad Ali Somnath ...

  4. Astronomy in Antarctica

    Science.gov (United States)

    Burton, Michael G.

    2010-10-01

    Antarctica provides a unique environment for astronomers to practice their trade. The cold, dry and stable air found above the high Antarctic plateau, as well as the pure ice below, offers new opportunities for the conduct of observational astronomy across both the photon and the particle spectrum. The summits of the Antarctic plateau provide the best seeing conditions, the darkest skies and the most transparent atmosphere of any earth-based observing site. Astronomical activities are now underway at four plateau sites: the Amundsen-Scott South Pole Station, Concordia Station at Dome C, Kunlun Station at Dome A and Fuji Station at Dome F, in addition to long duration ballooning from the coastal station of McMurdo, at stations run by the USA, France/Italy, China, Japan and the USA, respectively. The astronomy conducted from Antarctica includes optical, infrared, terahertz and sub-millimetre astronomy, measurements of cosmic microwave background anisotropies, solar astronomy, as well as high energy astrophysics involving the measurement of cosmic rays, gamma rays and neutrinos. Antarctica is also the richest source of meteorites on our planet. An extensive range of site testing measurements have been made over the high plateau sites. In this article, we summarise the facets of Antarctica that are driving developments in astronomy there, and review the results of the site testing experiments undertaken to quantify those characteristics of the Antarctic plateau relevant for astronomical observation. We also outline the historical development of the astronomy on the continent, and then review the principal scientific results to have emerged over the past three decades of activity in the discipline. These range from determination of the dominant frequencies of the 5 min solar oscillation in 1979 to the highest angular scale measurements yet made of the power spectrum of the CMBR anisotropies in 2010. They span through infrared views of the galactic ecology in star

  5. Chaco astronomies

    Science.gov (United States)

    Martín López, Alejandro

    2015-08-01

    This presentation discusses the result of 18 years of ethnographic and ethnohistorical studies on Chaco astronomies. The main features of the systems of astronomical knowledge of the Chaco Aboriginal groups will be discussed. In particular we will discuss the relevance of the Milky Way, the role of the visibility of the Pleiades, the ways in which the celestial space is represented, the constitution of astronomical orientations in geographic space, etc. We also address a key feature of their vision of the cosmos: the universe is seen by these groups as a socio-cosmos, where humans and non-humans are related. These are therefore actually socio-cosmologies. We will link this to the theories of Chaco Aboriginal groups about power and political relations.We will discuss how the study of Aboriginal astronomies must be performed along with the studies about astronomies of Creole people and European migrants, as well as anthropological studies about the science teaching in the formal education system and by the mass media. In this form we will discuss the relevance of a very complex system of interethnic relations for the conformation of these astronomical representations and practices.We will also discuss the general methodological implications of this case for the ethnoastronomy studies. In particular we will talk about the advantages of a study of regional scope and about the key importance of put in contact the ethnoastronomy with contemporary issues in social sciences.We also analyze the importance of ethnoastronomy studies in relation to studies of sociology of science, especially astronomy. We also study the potential impact on improving formal and informal science curricula and in shaping effective policies to protect the tangible and intangible astronomical heritage in a context of respect for the rights of Aboriginal groups.

  6. Fundamental astronomy

    CERN Document Server

    Kröger, Pekka; Oja, Heikki; Poutanen, Markku; Donner, Karl

    2017-01-01

    Now in its sixth edition this successful undergraduate textbook gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The chapters on galactic and extragalactic astronomy as well as cosmology were extensively modernized in the previous edition. In this new edition they have been further revised to include more recent results. The long chapter on the solar system has been split into two parts: the first one deals with the general properties, and the other one describes individual objects. A new chapter on exoplanets has been added to the end of the book next to the chapter on astrobiology. In response to the fact that astronomy has evolved enormously over the last few years, only a few chapters of this book have been left unmodified. Long considered a standard text for physical science maj...

  7. Humanising Astronomy

    Science.gov (United States)

    Levin, S.

    2008-06-01

    Universe Awareness (UNAWE) is an international programme that aims to expose underprivileged children (in the age group 4-10) to the inspirational aspects of astronomy. We are currently at the stage of developing materials that will be utilised in a diverse range of environments. This paper explores UNAWE's particular approach to developing tools which includes not only indigenous and folkloric astronomical knowledge, but also the culture of transmission of such knowledge. A specific understanding and explanation of the Universe, the Sun, Moon and stars is present in every culture and can be found contained in its history, legends and belief systems. By consciously embracing different ways of knowing the Universe and not uniquely the rational model, UNAWE places the humanising potential of astronomy at the centre of its purpose. Whilst inspiring curiosity, pride and a sense of ownership in one's own cultural identity, such an approach also exposes children to the diversity of other peoples and their cultures as well as the unifying aspects of our common scientific heritage. The means of creating and delivering the astronomy programme are as relevant to the desired educational outcomes as the content. The challenge in the design of materials is to communicate this stimulating message to the very young. Respect for alternative values systems, the need for dialogue and community participation, and where possible the production of materials using local resources is emphasised. This paper touches recent experiences liaising with communities in India, South Africa, Tunisia, Venezuela and Colombia.

  8. Radio astronomy

    CERN Document Server

    Alder, Berni

    1975-01-01

    Methods in Computational Physics, Volume 14: Radio Astronomy is devoted to the role of the digital computer both as a control device and as a calculator in addressing problems related to galactic radio noise. This volume contains four chapters and begins with a technical description of the hardware and the special data-handling problems of using radioheliography, with an emphasis on a selection of observational results obtained with the Culgoora radioheliograph and their significance to solar physics and to astrophysics in general. The subsequent chapter examines interstellar dispersion, i

  9. XUV astronomy

    International Nuclear Information System (INIS)

    Beuermann, K.P.; Technische Univ. Berlin

    1980-01-01

    A review is presented of the young field of extreme-ultraviolet astronomy at wavelengths from 50 Angstroem to 912 Angstroem. In recent years, it was realized that observations in this wavelength band could be performed due to the lucky circumstance that the sun is located in an extended region of extremely low interstellar gas density. Hence, the horizon for observations at 100 Angstroem due to the photoelectric opacity of the interstellar medium is typically at a distance of about 200 pc. Since 1975 a series of rocket and satellite observations have yielded the first positive results. Sources which radiate primarily in the extreme ultraviolet have been detected and even the small list of currently observed objects has had immediate impact on the studies of both stellar evolution and the interstellar medium. Diffuse emission from the interstellar medium results from a hot 10 5 to 10 6 K component of the interstellar gas. Prime stellar candidates for extreme-ultraviolet observations are (1) hot low-luminosity stars at the blue end of the HR diagram as, e.g., white dwarfs at the beginning of the cooling sequence, (2) atmospheric emission from stars surrounded by a hot corona or with flaring activity, (3) mass-exchanging binary systems as, e.g., main-sequence close binaries or catalysmic variables. The article discusses the prospects of extreme-ultraviolet astronomy and reviews the existing observations of extreme-ultraviolet emission from the interstellar medium and from stellar sources of the different categories. (orig.)

  10. Elementary astronomy

    Science.gov (United States)

    Fierro, J.

    2006-08-01

    In developing nations such as Mexico, basic science education has scarcely improved. There are multiple reasons for this problem; they include poor teacher training and curricula that are not challenging for students. I shall suggest ways in which astronomy can be used to improve basic education, it is so attractive that it can be employed to teach how to read and write, learn a second language, mathematics, physics, as well as geography. If third world nations do not teach science in an adequate way, they will be in serious problems when they will try to achieve a better standard of living for their population. I shall also address informal education, it is by this means that most adults learn and keep up to date with subjects that are not their specialty. If we provide good outreach programs in developing nations we can aid adult training; astronomy is ideal since it is particularly multidisciplinary. In particular radio and television programs are useful for popularization since they reach such wide audiences.

  11. Pulsar astronomy

    International Nuclear Information System (INIS)

    Lyne, A.G.; Graham-Smith, F.

    1990-01-01

    This account of the properties of pulsars tells an exciting story of discovery in modern astronomy. Pulsars, discovered in 1967, now take their place in a very wide range of astrophysics. They are one of the endpoints of stellar evolution, in which the core of a star collapses to a rapidly spinning neutron star a few kilometres in size. This book is an introductory account for those entering the field. It introduces the circumstances of the discovery and gives an overview of pulsar astrophysics. There are chapters on search techniques, distances, pulse timing, the galactic population of pulsars, binary and millisecond pulsars, geometry and physics of the emission regions, and applications to the interstellar medium. An important feature of this book is the inclusion of an up-to-date catalogue of all known pulsars. (author)

  12. Teaching and Learning Astronomy

    Science.gov (United States)

    Pasachoff, Jay; Percy, John

    2009-07-01

    Preface; Part I. Astronomy in the Curriculum Around the World: Preface; 1. Why astronomy is useful and should be included in the school curriculum John R. Percy; 2. Astronomy and mathematics education Rosa M. Ros; 3. Astronomy in the curriculum around the world; 4. Engaging gifted science students through astronomy Robert Hollow; 5. Poster highlights: astronomy in the curriculum around the world; Part II. Astronomy Education Research: Preface; 6. Astronomy education research down under John M. Broadfoot and Ian S. Ginns; 7. A contemporary review of K-16 astronomy education research Janelle M. Bailey and Timothy F. Slater; 8. Implementing astronomy education research Leonarda Fucili; 9. The Astronomy Education Review: report on a new journal Sidney C. Wolff and Andrew Fraknoi; 10. Poster highlights: astronomy education research; Part III. Educating Students: Preface; 11. Textbooks for K-12 astronomy Jay M. Pasachoff; 12. Distance/internet astronomy education David H. McKinnon; 13. Educating students with robotic telescopes - open discussion; 14. Poster highlights - educating students; Part IV. Educating teachers: Preface; 15. Pre-service astronomy education of teachers Mary Kay Hemenway; 16. In-service education of teachers Michèle Gerbaldi; 17. Poster highlights: educating teachers; Part V. Astronomy and Pseudoscience: Preface; 18. Astronomy, pseudoscience and rational thinking Jayant V. Narlikar; 19. Astronomical pseudosciences in North America John R. Percy and Jay M. Pasachoff; Part VI. Astronomy and Culture: Preface; 20. Teaching astronomy in other cultures: archeoastronomy Julieta Fierro; 21. Poster highlights: astronomy and culture; Part VII. Astronomy in Developing Countries: Preface; 22. Astronomy Curriculum for developing countries Case Rijsdijk; 23. Science education resources for the developing countries James C. White II; Part VIII. Public Outreach in Astronomy: Preface; 24. What makes informal education programs successful? Nahide Craig and Isabel

  13. Binocular astronomy

    CERN Document Server

    Tonkin, Stephen

    2014-01-01

    Binoculars have, for many, long been regarded as an “entry level” observational tool, and relatively few have used them as a serious observing instrument. This is changing! Many people appreciate the relative comfort of two-eyed observing, but those who use binoculars come to realize that they offer more than comfort. The view of the stars is more aesthetically pleasing and therefore binocular observers tend to observe more frequently and for longer periods. Binocular Astronomy, 2nd Edition, extends its coverage of small and medium binoculars to large and giant (i.e., up to 300mm aperture) binoculars and also binoviewers, which brings the work into the realm of serious observing instruments. Additionally, it goes far deeper into the varying optical characteristics of binoculars, giving newcomers and advanced astronomers the information needed to make informed choices on purchasing a pair. It also covers relevant aspects of the physiology of binocular (as in “both eyes”) observation. The first edition ...

  14. MALT 90: The Millimeter Astronomy Legacy Team 90 GHz Survey

    Science.gov (United States)

    Jackson, James M.; Foster, J.; Brooks, K.; Rathborne, J.; Longmore, S.

    2011-05-01

    We present the first season results of the Millimeter Astronomy Legacy Team 90 GHz Survey (MALT90), which will image 3 mm molecular line emission from 3,000 dense star-forming cores. MALT90 exploits the capability of the ATNF Mopra 22 m telescope for fast mapping and simultaneous imaging of 16 molecular lines near 90 GHz. These molecular lines will probe the cores’ physical, chemical, and evolutionary state. The target cores are selected from the 870 micron ATLASGAL survey to host the early stages of high-mass star formation and to span the complete range of evolutionary states from pre-stellar cores, to protostellar cores, and on to H II regions. Each core will be mapped at excellent angular (40'') and spectral (0.1 km/s) resolution. We present preliminary results for four key science projects: (1) determining the kinematic distances and Galactic distribution of dense cores, (2) establishing the distribution and evolution of angular momentum in a large sample of high-mass cores, (3) investigating the chemical evolution of dense cores, and (4) comparing the extragalactic molecular line-infrared luminosity correlations with those in Galactic cores. MALT90 will provide the definitive source list of high-mass dense cores for ALMA.

  15. Angular Accelerating White Light

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2015-08-01

    Full Text Available angular acceleration during propagation which is achieved by superpositions of Bessel beams with non-canonical phase functions. They demonstrate these angular accelerating fields by modulating the phase and amplitude of a supercontinuum source with the use...

  16. Recent Progress in Adjustable X-ray Optics for Astronomy

    Science.gov (United States)

    Reid, Paul B.; Allured, Ryan; Cotroneo, Vincenzo; McMuldroch, Stuart; Marquez, Vanessa; Schwartz, Daniel A.; Vikhlinin, Alexey; ODell, Stephen L.; Ramsey, Brian; Trolier-McKinstry, Susan; hide

    2014-01-01

    Two adjustable X-ray optics approaches are being developed for thin grazing incidence optics for astronomy. The first approach employs thin film piezoelectric material sputter deposited as a continuous layer on the back of thin, lightweight Wolter-I mirror segments. The piezoelectric material is used to correct mirror figure errors from fabrication, mounting/alignment, and any ground to orbit changes. The goal of this technology is to produce Wolter mirror segment pairs corrected to 0.5 arc sec image resolution. With the combination of high angular resolution and lightweight, this mirror technology is suitable for the Square Meter Arc Second Resolution Telescope for X-rays (SMART-X) mission concept.. The second approach makes use of electrostrictive adjusters and full shell nickel/cobalt electroplated replication mirrors. An array of radial adjusters is used to deform the full shells to correct the lowest order axial and azimuthal errors, improving imaging performance from the 10 - 15 arc sec level to 5 arc sec. We report on recent developments in both technologies. In particular, we discuss the use of insitu strain gauges on the thin piezo film mirrors for use as feedback on piezoelectric adjuster functionality, including their use for on-orbit figure correction. We also report on the first tests of full shell nickel/cobalt mirror correction with radial adjusters.

  17. High mass resolution, high angular acceptance time-of-flight mass spectroscopy for planetary missions under the Planetary Instrument Definition and Development Program (PIDDP)

    Science.gov (United States)

    Young, David T.

    1991-01-01

    This final report covers three years and several phases of work in which instrumentation for the Planetary Instrument Definition and Development Program (PIDDP) were successfully developed. There were two main thrusts to this research: (1) to develop and test methods for electrostatically scanning detector field-of-views, and (2) to improve the mass resolution of plasma mass spectrometers to M/delta M approximately 25, their field-of-view (FOV) to 360 degrees, and their E-range to cover approximately 1 eV to 50 keV. Prototypes of two different approaches to electrostatic scanning were built and tested. The Isochronous time-of-flight (TOF) and the linear electric field 3D TOF devices were examined.

  18. Professional AngularJS

    CERN Document Server

    Karpov, Valeri

    2015-01-01

    A comprehensive guide to AngularJS, Google's open-source client-side framework for app development. Most of the existing guides to AngularJS struggle to provide simple and understandable explanations for more advanced concepts. As a result, some developers who understand all the basic concepts of AngularJS struggle when it comes to building more complex real-world applications. Professional AngularJS provides a thorough understanding of AngularJS, covering everything from basic concepts, such as directives and data binding, to more advanced concepts like transclusion, build systems, and auto

  19. Measurement of the position resolution of the Gas Pixel Detector

    International Nuclear Information System (INIS)

    Soffitta, Paolo; Muleri, Fabio; Fabiani, Sergio; Costa, Enrico; Bellazzini, Ronaldo; Brez, Alessandro; Minuti, Massimo; Pinchera, Michele; Spandre, Gloria

    2013-01-01

    The Gas Pixel Detector was designed and built as a focal plane instrument for X-ray polarimetry of celestial sources, the last unexplored subtopics of X-ray astronomy. It promises to perform detailed and sensitive measurements resolving extended sources and detecting polarization in faint sources in crowded fields at the focus of telescopes of good angular resolution. Its polarimetric and spectral capability were already studied in earlier works. Here we investigate for the first time, with both laboratory measurements and Monte Carlo simulations, its imaging properties to confirm its unique capability to carry out imaging spectral-polarimetry in future X-ray missions.

  20. Astronomy and Politics

    Science.gov (United States)

    Steele, John M.

    The relationship between astronomy and politics is a complex but important part of understanding the practice of astronomy throughout history. This chapter explores some of the ways that astronomy, astrology, and politics have interacted, placing particular focus on the way that astronomy and astrology have been used for political purposes by both people in power and people who wish to influence a ruler's policy. Also discussed are the effects that politics has had on the development of astronomy and, in particular, upon the recording and preservation of astronomical knowledge.

  1. African Cultural Astronomy

    CERN Document Server

    Holbrook, Jarita C; Medupe, R. Thebe; Current Archaeoastronomy and Ethnoastronomy research in Africa

    2008-01-01

    Astronomy is the science of studying the sky using telescopes and light collectors such as photographic plates or CCD detectors. However, people have always studied the sky and continue to study the sky without the aid of instruments this is the realm of cultural astronomy. This is the first scholarly collection of articles focused on the cultural astronomy of Africans. It weaves together astronomy, anthropology, and Africa. The volume includes African myths and legends about the sky, alignments to celestial bodies found at archaeological sites and at places of worship, rock art with celestial imagery, and scientific thinking revealed in local astronomy traditions including ethnomathematics and the creation of calendars. Authors include astronomers Kim Malville, Johnson Urama, and Thebe Medupe; archaeologist Felix Chami, and geographer Michael Bonine, and many new authors. As an emerging subfield of cultural astronomy, African cultural astronomy researchers are focused on training students specifically for do...

  2. Measurements of the Sunyaev-Zel'dovich Effect in MACS J0647.7+7015 and MACS J1206.2-0847 at High Angular Resolution with MUSTANG

    Science.gov (United States)

    Young, Alexander H.; Mroczkowski, Tony; Romero, Charles; Sayers, Jack; Balestra, Italo; Clarke, Tracy E.; Czakon, Nicole; Devlin, Mark; Dicker, Simon R.; Ferrari, Chiara; Girardi, Marisa; Golwala, Sunil; Intema, Huib; Korngut, Phillip M.; Mason, Brian S.; Mercurio, Amata; Nonino, Mario; Reese, Erik D.; Rosati, Piero; Sarazin, Craig; Umetsu, Keiichi

    2015-08-01

    We present high resolution (9″) imaging of the Sunyaev-Zel’dovich Effect (SZE) toward two massive galaxy clusters, MACS J0647.7+7015 (z = 0.591) and MACS J1206.2-0847 (z = 0.439). We compare these 90 GHz measurements, taken with the Multiplexed Squid/TES Array at Ninety Gigahertz (MUSTANG ) receiver on the Green Bank Telescope, with generalized Navarro-Frenk-White (gNFW) models derived from Bolocam 140 GHz SZE data as well as maps of the thermal gas derived from Chandra X-ray observations. We adopt a serial-fitting approach, in which gNFW models are first fit to the Bolocam data and then compared to the MUSTANG data to determine an overall best-fit model. For MACS J0647.7+7015, we find a gNFW profile with core slope parameter γ = 0.9 fits the MUSTANG image with {χ }{red}2=1.005 and probability to exceed (PTE) = 0.34. For MACS J1206.2-0847, we find γ =0.7, {χ }{red}2=0.993, and PTE = 0.70. In addition, we find a significant (>3σ) residual SZE feature in MACS J1206.2-0847 coincident with a group of galaxies identified in Very Large Telescope data and filamentary structure found in a weak-lensing mass reconstruction. We suggest the detected sub-structure may be the SZE decrement from a low mass foreground group or an infalling group. Giant Metrewave Radio Telescope measurements at 610 MHz reveal diffuse extended radio emission to the west, which we posit is either an active galactic nucleus-driven radio lobe, a bubble expanding away from disturbed gas associated with the SZE signal, or a bubble detached and perhaps re-accelerated by sloshing within the cluster. Using the spectroscopic redshifts available, we find evidence for a foreground (z = 0.423) or infalling group, coincident with the residual SZE feature.

  3. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. N. Kameswara Rao. Articles written in Journal of Astrophysics and Astronomy. Volume 26 Issue 2-3 June-September 2005 pp 331-338. High Resolution Stellar Spectroscopy with VBT Echelle Spectrometer · N. Kameswara Rao S. Sriram K. Jayakumar F. Gabriel.

  4. Imaging X-ray astronomy

    International Nuclear Information System (INIS)

    Elvis, M.

    1990-01-01

    The launch of the High Energy Astrophysical Observatory, more appealingly called the Einstein Observatory, marked one of the most revolutionary steps taken in astrophysics this century. Its greater sensitivity compared with earlier satellites and its ability to make high spacial and spectral resolution observations transformed X-ray astronomy. This book is based on a Symposium held in Cambridge, Massachusetts, to celebrate a decade of Einstein Observatory's achievements. It discusses the contributions that this satellite has made to each area of modern astrophysics and the diversity of the ongoing work based on Einstein data. There is a guide to each of the main data bases now coming on-line to increase the availability and to preserve this valuable archive for the future. A review of NASA's next big X-ray mission, AXAF, and a visionary program for novel X-ray astronomy satellites by Riccardo Giacconi conclude this wide-ranging volume. (author)

  5. Angular correlation methods

    International Nuclear Information System (INIS)

    Ferguson, A.J.

    1974-01-01

    An outline of the theory of angular correlations is presented, and the difference between the modern density matrix method and the traditional wave function method is stressed. Comments are offered on particular angular correlation theoretical techniques. A brief discussion is given of recent studies of gamma ray angular correlations of reaction products recoiling with high velocity into vacuum. Two methods for optimization to obtain the most accurate expansion coefficients of the correlation are discussed. (1 figure, 53 references) (U.S.)

  6. The next detectors for gravitational wave astronomy

    Science.gov (United States)

    Blair, David; Ju, Li; Zhao, ChunNong; Wen, LinQing; Miao, HaiXing; Cai, RongGen; Gao, JiangRui; Lin, XueChun; Liu, Dong; Wu, Ling-An; Zhu, ZongHong; Hammond, Giles; Paik, Ho Jung; Fafone, Viviana; Rocchi, Alessio; Blair, Carl; Ma, YiQiu; Qin, JiaYi; Page, Michael

    2015-12-01

    This paper focuses on the next detectors for gravitational wave astronomy which will be required after the current ground based detectors have completed their initial observations, and probably achieved the first direct detection of gravitational waves. The next detectors will need to have greater sensitivity, while also enabling the world array of detectors to have improved angular resolution to allow localisation of signal sources. Sect. 1 of this paper begins by reviewing proposals for the next ground based detectors, and presents an analysis of the sensitivity of an 8 km armlength detector, which is proposed as a safe and cost-effective means to attain a 4-fold improvement in sensitivity. The scientific benefits of creating a pair of such detectors in China and Australia is emphasised. Sect. 2 of this paper discusses the high performance suspension systems for test masses that will be an essential component for future detectors, while sect. 3 discusses solutions to the problem of Newtonian noise which arise from fluctuations in gravity gradient forces acting on test masses. Such gravitational perturbations cannot be shielded, and set limits to low frequency sensitivity unless measured and suppressed. Sects. 4 and 5 address critical operational technologies that will be ongoing issues in future detectors. Sect. 4 addresses the design of thermal compensation systems needed in all high optical power interferometers operating at room temperature. Parametric instability control is addressed in sect. 5. Only recently proven to occur in Advanced LIGO, parametric instability phenomenon brings both risks and opportunities for future detectors. The path to future enhancements of detectors will come from quantum measurement technologies. Sect. 6 focuses on the use of optomechanical devices for obtaining enhanced sensitivity, while sect. 7 reviews a range of quantum measurement options.

  7. Armenian Cultural Astronomy

    Science.gov (United States)

    Farmanyan, S. V.; Mickaelian, A. M.

    2015-07-01

    Cultural Astronomy is the reflection of sky events in various fields of nations' culture. In foreign literature this field is also called "Astronomy in Culture" or "Astronomy and Culture". Cultural astronomy is the set of interdisciplinary fields studying the astronomical systems of current or ancient societies and cultures. It is manifested in Religion, Mythology, Folklore, Poetry, Art, Linguistics and other fields. In recent years, considerable attention has been paid to this sphere, particularly international organizations were established, conferences are held and journals are published. Armenia is also rich in cultural astronomy. The present paper focuses on Armenian archaeoastronomy and cultural astronomy, including many creations related to astronomical knowledge; calendars, rock art, mythology, etc. On the other hand, this subject is rather poorly developed in Armenia; there are only individual studies on various related issues (especially many studies related to Anania Shirakatsi) but not coordinated actions to manage this important field of investigation.

  8. Angular Acceleration without Torque?

    Science.gov (United States)

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  9. Rotations and angular momentum

    International Nuclear Information System (INIS)

    Nyborg, P.; Froyland, J.

    1979-01-01

    This paper is devoted to the analysis of rotational invariance and the properties of angular momentum in quantum mechanics. In particular, the problem of addition of angular momenta is treated in detail, and tables of Clebsch-Gordan coefficients are included

  10. Journey of Ethiopia Astronomy

    Science.gov (United States)

    Belay Tessema, Solomon

    2015-08-01

    Ancient astronomy had contributed away for the modern development of astronomy. The history of astronomy development in Ethiopian was liked with different beliefs and culture of the society. The Ethiopians were the first who invented the science of stars, and gave names to the planets, not at random and without meaning, but descriptive of the qualities which they conceived them to possess; and it was from them that this art passed, still in an imperfect state, to the Egyptians. Even though, Ethiopian’s contributions for astronomy in the world were immense but the journey of modern astronomy is still in the infant stage. The modern astronomy and space program in Ethiopia was started in 2004 in well organized form from three individuals to the public. In the past eleven years of journey of astronomy development in Ethiopia was the most challenging from national to international level. After strong struggle of a few committed individuals for the past eleven years the development of astronomy is completely changed from dark age to bright age. This paper will try to address the details of journey of astronomy in Ethiopia.

  11. Space and astronomy

    CERN Document Server

    Kirkland, Kyle

    2010-01-01

    Some daring explorers like to study distant frontiers by venturing out into them, but others prefer to study them by bringing them, or representative samples, a little closer to the lab. Both options are pursued in the fields of space and astronomy. Space exploration and astronomy are intricately linked and are examined in-depth in this guide. Dedicated to the scientists who explore the frontiers of space and astronomy-and the results of their unfamiliar findings-each chapter in Space and Astronomy explores one of the frontiers of this science. The development of technology, such as rocket pro

  12. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.

    2015-01-01

    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  13. Astronomy research in Bolivia

    Science.gov (United States)

    Polojentsev, Dmitry D.; Zalles, R.

    1. An astronomical expedition from Pulkovo observatory in Bolivia, near Tarija was organized in 1982. The first telscope was an astrograph ( D=23 cm, F=230 cm, field = 5x5 degrees ). Sucsessful observations on this instrument are still being made. In all 7 astronomical instuments were installed. Now they are the National Bolivian Observatory. 2. The main results of astrophysical investigations were devoted to 4-color photometry of supernova 1987A and the creation of a Spectrophotometric Catalogue of 60 Selected Southern Stars. 3. The main results of astrometrical investigations were made on two catalogue problems: Photographical Catalogue for Southern Star (FOCAT-S) and Equatorial Catalogue (ECAT). The first was the foundation for southern part of PPM Catalogue. 4. A time Service was organized in 1988 in Tarija at the National Astronomical Observatory "Santa Ana". In 1997 Pulkovo observatory assisted to reconstract it. 5. The only Planetarium in Bolivia "Max Schreider"in La Paz was founded in 1976. 6. The Associacion Boliviana de Astronomia (ABA) was organized in 1969 in accordance with a Goverment Resolution. It has branches in Potosy, Santa Cruz, Sucre, Tarija etc. 7. The development of the astronomy in Bolivia depends directly on cooperation with the astronomically developed countries.

  14. Quark Orbital Angular Momentum

    Directory of Open Access Journals (Sweden)

    Burkardt Matthias

    2015-01-01

    Full Text Available Definitions of orbital angular momentum based on Wigner distributions are used as a framework to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. We find that the difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.

  15. Extragalactic infrared astronomy

    International Nuclear Information System (INIS)

    Gondhalekar, P.M.

    1985-05-01

    The paper concerns the field of Extragalactic Infrared Astronomy, discussed at the Fourth RAL Workshop on Astronomy and Astrophysics. Fifteen papers were presented on infrared emission from extragalactic objects. Both ground-(and aircraft-) based and IRAS infrared data were reviewed. The topics covered star formation in galaxies, active galactic nuclei and cosmology. (U.K.)

  16. Indian Astronomy: History of

    Science.gov (United States)

    Mercier, R.; Murdin, P.

    2002-01-01

    From the time of A macronryabhat under dota (ca AD 500) there appeared in India a series of Sanskrit treatises on astronomy. Written always in verse, and normally accompanied by prose commentaries, these served to create an Indian tradition of mathematical astronomy which continued into the 18th century. There are as well texts from earlier centuries, grouped under the name Jyotishaveda macronn d...

  17. Astronomy in Mozambique

    Science.gov (United States)

    Ribeiro, Valério A. R. M.; Paulo, Cláudio M.

    2015-03-01

    We present the state of Astronomy in Mozambique and how it has evolved since 2009 following the International Year of Astronomy. Activities have been lead by staff at University Eduardo Mondlane and several outreach activities have also flourished. In 2010 the University introduced its first astronomy module, Introduction to Astronomy and Astrophysics, for the second year students in the Department of Physics. The course has now produced the first students who will be graduating in late 2012 with some astronomy content. Some of these students will now be looking for further studies and those who have been keen in astronomy have been recommended to pursue this as a career. At the university level we have also discussed on the possibility to introduce a whole astronomy course by 2016 which falls well within the HCD that the university is now investing in. With the announcement that the SKA will be split between South Africa with its partner countries (including Mozambique), and Australia we have been working closely with the Ministry of Science and Technology to make astronomy a priority on its agenda. In this respect, an old telecommunications antenna is being converted by the South Africa SKA Project Office, and donated to Mozambique for educational purposes. It will be situated in Maluana, Mozambique.

  18. Handbook of Practical Astronomy

    CERN Document Server

    Roth, Günter D

    2009-01-01

    With amateurs, students, and teachers of astronomy in high schools and colleges particularly in mind, the Handbook of Practical Astronomy is an essential source to demonstrate trends and variety of astronomical observations. The book presents the substance of celestial bodies for the amateur observer: the planets, the stars, and the galaxies. The sun is the local link to the other stars, the nexus of cosmic evolution. The solar system is made up by the sun and all the celestial bodies orbit it. This system is of special interest for the observing amateur. The Handbook of Practial Astronomy spans astronomy, education and computing. Like many other fields of science, astronomy has become digitized and data rich in recent years. Besides the references at the end of each chapter, there are the notes in the margins with astronomical news and observing highlights on the web.

  19. Optical Angular Momentum

    International Nuclear Information System (INIS)

    Arimondo, Ennio

    2004-01-01

    For many years the Institute of Physics has published books on hot topics based on a collection of reprints from different journals, including some remarks by the editors of each volume. The book on Optical Angular Momentum, edited by L Allen, S M Barnett and M J Padgett, is a recent addition to the series. It reproduces forty four papers originally published in different journals and in a few cases it provides direct access to works not easily accessible to a web navigator. The collection covers nearly a hundred years of progress in physics, starting from an historic 1909 paper by Poynting, and ending with a 2002 paper by Padgett, Barnett and coworkers on the measurement of the orbital angular momentum of a single photon. The field of optical angular momentum has expanded greatly, creating an interdisciplinary attraction for researchers operating in quantum optics, atomic physics, solid state physics, biophysics and quantum information theory. The development of laser optics, especially the control of single mode sources, has made possible the specific design of optical radiation modes with a high degree of control on the light angular momentum. The editors of this book are important figures in the field of angular momentum, having contributed to key progress in the area. L Allen published an historical paper in 1999, he and M J Padgett (together with M Babiker) produced few years ago a long review article which is today still the most complete basic introduction to the angular momentum of light, while S M Barnett has contributed several high quality papers to the progress of this area of physics. The editors' choice provides an excellent overview to all readers, with papers classified into eight different topics, covering the basic principles of the light and spin and orbital angular momentum, the laboratory tools for creating laser beams carrying orbital angular momentum, the optical forces and torques created by laser beams carrying angular momentum on

  20. Astronomy Landscape in Africa

    Science.gov (United States)

    Nemaungani, Takalani

    2015-01-01

    The vision for astronomy in Africa is embedded in the African Space Policy of the African Union in early 2014. The vision is about positioning Africa as an emerging hub for astronomy sciences and facilities. Africa recognized the need to take advantage of its natural resource, the geographical advantage of the clear southern skies and pristine sites for astronomy. The Pan African University (PAU) initiative also presents an opportunity as a post-graduate training and research network of university nodes in five regions of Africa and supported by the African Union. The Southern African node based in South Africa concentrates on space sciences which also includes astronomy. The PAU aims to provide the opportunity for advanced graduate training and postgraduate research to high-performing African students. Objectives also include promoting mobility of students and teachers and harmonizing programs and degrees.A number of astronomy initiatives have burgeoned in the Southern African region and these include the Southern Africa Largest Optical Telescope (SALT), HESS (High Energy Stereoscopic System), the SKA (Square Kilometre Array) and the AVN (African Very Long Baseline Interferometer Network). There is a growing appetite for astronomy sciences in Africa. In East Africa, the astronomy community is well organized and is growing - the East African Astronomical society (EAAS) held its successful fourth annual conference since 2010 on 30 June to 04 July 2014 at the University of Rwanda. Centred around the 'Role of Astronomy in Socio-Economic Transformation,' this conference aimed at strengthening capacity building in Astronomy, Astrophysics and Space Science in general, while providing a forum for astronomers from the region to train young and upcoming scientists.

  1. Teaching Astronomy with Technology

    Science.gov (United States)

    Austin, Carmen; Impey, Chris David; Wenger, Matthew

    2015-01-01

    Students today are expected to have access to computers and the Internet. Students young and old, in school and out of school, are interested in learning about astronomy, and have computers to use for this. Teach Astronomy is a website with a comprehensive digital astronomy textbook freely available to students and educators. In addition to the textbook, there are astronomy Wikipedia articles, image archives from Astronomy Picture of the Day and AstroPix, and video lectures covering all topics of astronomy. Teach Astronomy has a unique search tool called the wikimap that can be used to search through all of the resources on the site. Astronomy: State of the Art (ASOTA) is a massive, open, online course (MOOC). Over 18,000 students have enrolled over the past year and half. This MOOC has been presented in various forms. First, only to students on the web, with content released weekly on host site Udemy. Then to university students who met formally in the classroom for educational activities, but were also expected to watch lectures online on their own time. Presently, it is available online for students to go at their own pace. In the future it will be available in an extended format on a new host site, Coursera. ASOTA instructors use social media to interact with students. Students ask questions via the course host site, Udemy. Live question and answer sessions are conducted using Google Hangouts on Air, and interesting and relevant astronomy news, or supplementary educational content is shared via the ASOTA Facebook page. Teaching on the Internet may seem impersonal and impractical, but by learning to use all of these tools, instructors have the ability to interact with students, and keep them engaged.

  2. Discovering Astronomy Through Poetry

    Science.gov (United States)

    Mannone, John C.

    2011-05-01

    The literature is replete with astronomical references. And much of that literature is poetry. Using this fact, not only can the teacher infuse a new appreciation of astronomy, but also, the student has the opportunity to rediscover history through astronomy. Poetry can be an effective icebreaker in the introduction of new topics in physics and astronomy, as well as a point of conclusion to a lecture. This presentation will give examples of these things from the ancient literature (sacred Hebraic texts), classical literature (Homer's Iliad and Odyssey), traditional poetry (Longfellow, Tennyson and Poe) and modern literature (Frost, Kooser, and others, including the contemporary work of this author).

  3. Astronomy and culture

    CERN Document Server

    Hetherington, Edith

    2009-01-01

    While astronomy is a burgeoning science, with tremendous increases in knowledge every year, it also has a tremendous past, one that has altered humanity's understanding of our place in the universe. The impact of astronomy on culture - whether through myths and stories, or through challenges to the intellectual status quo - is incalculable. This volume in the Greenwood Guides to the Universe series examines how human cultures, in all regions and time periods, have tried to make sense of the wonders of the universe. Astronomy and Culture shows students how people throughout time have struggled

  4. Mathematical Astronomy in India

    Science.gov (United States)

    Plofker, Kim

    Astronomy in South Asia's Sanskrit tradition, apparently originating in simple calendric computations regulating the timing of ancient ritual practices, expanded over the course of two or three millennia to include detailed spherical models, an endless variety of astrological systems, and academic mathematics in general. Assimilating various technical models, methods, and genres from the astronomy of neighboring cultures, Indian astronomers created new forms that were in turn borrowed by their foreign counterparts. Always recognizably related to the main themes of Eurasian geocentric mathematical astronomy, Indian astral science nonetheless maintained its culturally distinct character until Keplerian heliocentrism and Newtonian mechanics replaced it in colonial South Asia's academic mainstream.

  5. The search for and registration of superweak angular ground motions

    International Nuclear Information System (INIS)

    Budagov, J.; Lyablin, M.; Shirkov, G.

    2013-01-01

    The Earth's surface angular oscillations of the seismic, industrial and terrestrial origins have been registered with the high-resolution inclinometer of a new design concept. The microseismic peak was first recognized in the ground microradian motion

  6. Stamping through astronomy

    CERN Document Server

    Dicati, Renato

    2013-01-01

    Stamps and other postal documents are an attractive vehicle for presenting astronomy and its development. Written with expertise and great enthusiasm, this unique book offers a historical and philatelic survey of astronomy and some related topics on space exploration. It contains more than 1300 color reproductions of stamps relating to the history of astronomy, ranging from the earliest observations of the sky to modern research conducted with satellites and space probes. Featured are the astronomers and astrophysicists who contributed to this marvelous story – not only Ptolemy, Copernicus, Kepler, Newton, Herschel, and Einstein but also hundreds of other minor protagonists who played an important role in the development of this, the most ancient yet the most modern of all the sciences. The book also examines in depth the diverse areas which have contributed to the history of astronomy, including the instrumentation, the theories, and the observations. Many stamps illustrate the beauty and the mystery of ce...

  7. Astronomy in Everyday Life

    Science.gov (United States)

    Rosenberg, M.; Bladon, G.; Russo, P.; Christensen, L. L.

    2014-01-01

    For a long time astronomers and other scientists believed that the importance of their work was evident to society. But in these difficult days of financial austerity, even the most obvious benefits of science have to undergo careful scrutiny. So, now more than ever is the time to highlight the importance of astronomy as a field in terms of its contributions to our technology, our mind sets and our lives. Here we will outline both the tangible and intangible reasons why astronomy is an important part of society. Whilst considerable attention will be given to technology and knowledge transfer from astronomy, perhaps the most important contribution outlined is the awareness that astronomy gives us of the vastness of the Universe and our place within it.

  8. Cultural Astronomy in Japan

    Science.gov (United States)

    Renshaw, Steven L.

    While Japan is known more for its contributions to modern astronomy than its archaeoastronomical sites, there is still much about the culture's heritage that is of interest in the study of cultural astronomy. This case study provides an overview of historical considerations necessary to understand the place of astronomy in Japanese society as well as methodological considerations that highlight traditional approaches that have at times been a barrier to interdisciplinary research. Some specific areas of study in the cultural astronomy of Japan are discussed including examples of contemporary research based on interdisciplinary approaches. Japan provides a fascinating background for scholars who are willing to go beyond their curiosity for sites of alignment and approach the culture with a desire to place astronomical iconography in social context.

  9. Galactic radio astronomy

    CERN Document Server

    Sofue, Yoshiaki

    2017-01-01

    This book is a concise primer on galactic radio astronomy for undergraduate and graduate students, and provides wide coverage of galactic astronomy and astrophysics such as the physics of interstellar matter and the dynamics and structure of the Milky Way Galaxy and galaxies. Radio astronomy and its technological development have led to significant progress in galactic astronomy and contributed to understanding interstellar matter and galactic structures. The book begins with the fundamental physics of radio-wave radiation, i.e., black body radiation, thermal emission, synchrotron radiation, and HI and molecular line emissions. The author then gives overviews of ingredients of galactic physics, including interstellar matter such as the neutral (HI), molecular hydrogen, and ionized gases, as well as magnetic fields in galaxies. In addition, more advanced topics relevant to the Galaxy and galaxies are also contained here: star formation, supernova remnants, the Galactic Center and black holes, galactic dynamics...

  10. Data analysis in astronomy

    International Nuclear Information System (INIS)

    Di Gesu, V.; Crane, P.; Friedman, J.H.; Levialdi, S.; Scarsi, L.

    1985-01-01

    This book presents information on the following topics: the data analysis facilities that astronomers want; time analysis in astronomy; tools for periodicity searches; graphical methods of exploratory data analysis; multivariate statistics to analyze extraterrestrial particles from the ocean floor; application of bootstrap sampling in gamma-ray astronomy; an automated method for velocity field analysis; panel discussion on data analysis trends in x-ray and gamma-ray astronomy; the Groningen image processing system; astronomical input to image processing - astronomical output from image processing; 2-D photometry; spectrometry; time dependent analysis; solar image processing with the Clark Lake Radioheliograph; steps toward parallel processing; new architectures for image processing; data structures and languages in support of parallel image processing for astronomy; and morphology and probability in image processing

  11. Gravitational-wave astronomy

    Science.gov (United States)

    Press, W. H.; Thorne, K. S.

    1972-01-01

    The significance of experimental evidence for gravitational waves is considered for astronomy. Properties, generation, and astrophysical sources of the waves are discussed. Gravitational wave receivers and antennas are described. A review of the Weber experiment is presented.

  12. Astronomy, Astrology, and Medicine

    Science.gov (United States)

    Greenbaum, Dorian Gieseler

    Astronomy and astrology were combined with medicine for thousands of years. Beginning in Mesopotamia in the second millennium BCE and continuing into the eighteenth century, medical practitioners used astronomy/astrology as an important part of diagnosis and prescription. Throughout this time frame, scientists cited the similarities between medicine and astrology, in addition to combining the two in practice. Hippocrates and Galen based medical theories on the relationship between heavenly bodies and human bodies. In an enduring cultural phenomenon, parts of the body as well as diseases were linked to zodiac signs and planets. In Renaissance universities, astronomy and astrology were studied by students of medicine. History records a long tradition of astrologer-physicians. This chapter covers the topic of astronomy, astrology, and medicine from the Old Babylonian period to the Enlightenment.

  13. NRAO Response to NSF Senior Review of Astronomy Facilities

    Science.gov (United States)

    2006-11-01

    The National Science Foundation's (NSF) Astronomy Senior Review Committee report (pdf file), released today, made major recommendations for restructuring the NSF's ground-based astronomy efforts, including significant changes for the National Radio Astronomy Observatory (NRAO). The committee's report urged that leadership in radio astronomy, including millimeter- and submillimeter-wave observatories, "remain centered at NRAO as it is, by far, the largest radio astronomy organization in the world." The report praised the record of management of NRAO and the scientific capabilities of the Atacama Large Millimeter/submillimeter Array (ALMA), the Expanded Very Large Array (EVLA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Long Baseline Array (VLBA). However, the report also recommended that some reductions and changes occur at the NRAO by 2011. Specifically, the report recommended that: (a) VLBA operations make a transition to a significant reliance on international funding or risk closure; (b) GBT operations costs be reduced; and (c) NRAO scientific staff costs be reduced. "The Senior Review Committee had the very difficult task of reconciling the needs of current facilities and funding new facilities for the future of astronomy. We appreciate their efforts and look forward to working with the NSF to ensure that the valuable and unique research capabilities of our NRAO telescopes continue to serve the astronomical community," said Dr. Fred K.Y. Lo, NRAO Director. The VLBA provides the greatest angular resolution, or ability to see fine detail, of any telescope in the world, greatly exceeding the capabilities of the Hubble Space Telescope and the future Square Kilometre Array. The committee recognized that, "if the VLBA is closed, a unique capability would likely be lost for decades." "The VLBA is used by scientists from around the world because of its unique capabilities. It has produced landmark research milestones and the committee recognized in its

  14. Astronomy in Mexico

    Science.gov (United States)

    Lee, William H.

    2013-01-01

    Mexican astronomy has a long standing tradition of excellence in research. After a brief review of its history, I outline the current profile of the community, the available infrastructure and participating institutions, and give a glimpse into the future through current projects. The development of astronomy can serve as a powerful lever for science, technological development, education and outreach, as well as for improving the much needed link between basic research and industry development.

  15. Music and Astronomy

    Science.gov (United States)

    Caballero, José A.; González Sánchez, S.; Caballero, I.

    What do Brian May (Queen's lead guitarist), William Herschel and the Jupiter Symphony have in common? And a white dwarf, a piano and Lagartija Nick? At first glance, there is no connection between them, nor between the Music and the Astronomy. However, there are many revealing examples of musical Astronomy and astronomical Music. This four-page proceeding describes the sonorous poster that we showed during the VIII Scientific Meeting of the Spanish Astronomical Society.

  16. New developments of radio-astronomy in the sub-mmwave region

    International Nuclear Information System (INIS)

    Matthews, H.E.

    1989-01-01

    Astronomy at submillimeter wavelengths is a technically demanding discipline which is coming of age through the recent construction of several large ground-based facilities and continuing advances in receiver technology. The current status of the field is reviewed with attention being paid particularly to the potential contributions to astrophysics and to the major difficulties facing the observer at these wavelengths. The results of surveys for molecular transitions and examples of the uses of such lines in determining excitation and other parameters of circum- and interstellar material is discussed. Observations of continuum radiation, principally of cold dust, is also touched upon. Both line and continuum studies have great potential at these wavelengths in the study of protostellar objects, as well as in the late stages of stellar evolution. Prospects for the future development of sub-mm astronomy are bright; plans to overcome the limitations imposed by the atmosphere using satellite technology, and to increase angular resolution by the use of interferometry are reviewed

  17. Design and modeling of an additive manufactured thin shell for x-ray astronomy

    Science.gov (United States)

    Feldman, Charlotte; Atkins, Carolyn; Brooks, David; Watson, Stephen; Cochrane, William; Roulet, Melanie; Willingale, Richard; Doel, Peter

    2017-09-01

    Future X-ray astronomy missions require light-weight thin shells to provide large collecting areas within the weight limits of launch vehicles, whilst still delivering angular resolutions close to that of Chandra (0.5 arc seconds). Additive manufacturing (AM), also known as 3D printing, is a well-established technology with the ability to construct or `print' intricate support structures, which can be both integral and light-weight, and is therefore a candidate technique for producing shells for space-based X-ray telescopes. The work described here is a feasibility study into this technology for precision X-ray optics for astronomy and has been sponsored by the UK Space Agency's National Space Technology Programme. The goal of the project is to use a series of test samples to trial different materials and processes with the aim of developing a viable path for the production of an X-ray reflecting prototype for astronomical applications. The initial design of an AM prototype X-ray shell is presented with ray-trace modelling and analysis of the X-ray performance. The polishing process may cause print-through from the light-weight support structure on to the reflecting surface. Investigations in to the effect of the print-through on the X-ray performance of the shell are also presented.

  18. Fission fragment angular momentum

    International Nuclear Information System (INIS)

    Frenne, D. De

    1991-01-01

    Most of the energy released in fission is converted into translational kinetic energy of the fragments. The remaining excitation energy will be distributed among neutrons and gammas. An important parameter characterizing the scission configuration is the primary angular momentum of the nascent fragments. Neutron emission is not expected to decrease the spin of the fragments by more than one unit of angular momentum and is as such of less importance in the determination of the initial fragment spins. Gamma emission is a suitable tool in studying initial fragment spins because the emission time, number, energy, and multipolarity of the gammas strongly depend on the value of the primary angular momentum. The main conclusions of experiments on gamma emission were that the initial angular momentum of the fragments is large compared to the ground state spin and oriented perpendicular to the fission axis. Most of the recent information concerning initial fragment spin distributions comes from the measurement of isomeric ratios for isomeric pairs produced in fission. Although in nearly every mass chain isomers are known, only a small number are suitable for initial fission fragment spin studies. Yield and half-life considerations strongly limit the number of candidates. This has the advantage that the behavior of a specific isomeric pair can be investigated for a number of fissioning systems at different excitation energies of the fragments and fissioning nuclei. Because most of the recent information on primary angular momenta comes from measurements of isomeric ratios, the global deexcitation process of the fragments and the calculation of the initial fragment spin distribution from measured isomeric ratios are discussed here. The most important results on primary angular momentum determinations are reviewed and some theoretical approaches are given. 45 refs., 7 figs., 2 tabs

  19. Bad Astronomy Goes Hollywood

    Science.gov (United States)

    Plait, P.

    2003-05-01

    It can be argued that astronomy is the oldest of all the sciences, so you'd think that after all this time people would have a pretty good understanding of it. In reality, however, misconceptions about astronomy abound, and even basic concepts are misunderstood. There are many sources of these cosmic misconceptions, including incorrect textbooks, parents and/or teachers who don't understand astronomy and therefore spread misinformation, urban legends, and so on. Perhaps the most pervasive source of bad astronomy is Hollywood. Science fiction movies are enormously popular, but are commonly written and directed by people who don't have even a passing familiarity with astronomy. The smash hit "Armageddon" (the number one box office movie of 1998), for example, used vast quantities of incorrect astronomy in the plot. It reinforced such popular misconceptions as huge asteroids impacting the Earth with little warning, small meteorites being hot when they impact, air existing in space, and that a simple bomb can blow up an asteroid the size of a small moon (even when the bomb is buried only 800 feet deep!). However, movie scenes can be used as a hook that engages the student, helping them learn and remember the correct science. In this talk, I will light-heartedly discuss specific examples of common misinformation, using movie clips, diagrams, and a splash of common sense to show just where Hollywood gets it wrong, and what you can do to help students and the public get it right.

  20. Instrumentation for astronomy

    Science.gov (United States)

    Sun, Yin Sheng

    1999-12-01

    The aim of this thesis was to develop two new infrared astronomical instruments, the University of New South Wales Infrared Fabry-Perot spectrometer (UNSWIRF) and the Infrared Camera of the University of New South Wales (IRC-UNSW), and modify an optics for one existing astronomical instrument, the Automated Patrol Telescope (APT). The optical modification of the APT overcame the problem of a curved focal plane and increased the flat field of view from 0.9° to 5°, twice as big as our original goal. In addition, glass filters of 5-mm thickness can now be inserted into its f/1 beam without image blurring. The simulation, analysis and redesign of the optical system are presented in detail. Several results from testing on the sky are presented as well. UNSWIRF is a near-infrared tunable imaging spectrometer used in conjunction with IRIS on the Anglo-Australian Telescope (AAT). It is the first successful infrared Fabry-Perot spectrometer developed in Australia. Its many challenging features, such as the wide field of view, high spectral and spatial resolution and wide tunable range have been rewarded by exciting observing results obtained during commissioning in February 1996. A major contribution of this thesis has been in the calibration of the Fabry-Perot etalon. IRC-UNSW is a new near-infrared camera with a tunable Fabry-Perot for infrared astronomy. IRC-UNSW is designed for use on the 4-m Anglo-Australian Telescope (AAT) and the 2.3-m telescope of the Australian National University. The camera optics use a novel design of three off-axis mirrors, allowing correction of the off-axis aberrations in the telescopes themselves, and producing images with FWHM blur circles of 10 mm or less over a wide field of view without chromatic affects. An external Fabry- Perot etalon is used as a high-resolution spectrometer. In its opto-mechanical design, the performance of the camera with respect to thermal effects, stray light, misalignment and manufacturing errors have been

  1. Stratospheric Observatory For Infrared Astronomy (SOFIA). Phase A: System concept description

    Science.gov (United States)

    1995-01-01

    Infrared astronomers have made significant discoveries using the NASA/Ames Research Center C-141 Kuiper airborne Observatory (KAO) with its 0.91-meter telescope. The need for a 3-meter class airborne observatory has been established to improve astronomy data gathering capability. The new system envisioned by NASA and the international community of astronomers will be known as the Stratospheric Observatory for Infrared Astronomy (SOFIA). The platform of choice for SOFIA is a modified Boeing 747SP. SOFIA is viewed as a logical progression from the KAO. Potentially, a 3-meter telescope operating at the altitude achievable by the 747SP aircraft can be 11 times more sensitive than the KAO, can have 3.3 times better angular resolution, and will allow observations of compact sources in a volume of space up to 36 times that of the KAO. The KAO has enabled detection of about 15 percent of the far infrared IRAS survey point-sources; SOFIA should be able to detect them all. This document presents the results of in-house ARC and contracted concept definition studies for SOFIA. Using the ARC-based Kuiper Airborne Observatory as a basis for both SOFIA design and operations concepts, the SOFIA system concept has been developed with a view toward demonstrating mission and technical feasibility, and preparing preliminary cost estimates. The reference concept developed is not intended to represent final design, and should be treated accordingly. The most important products of this study, other than demonstration of system feasibility, are the understanding of system trade-offs and the development of confidence in the technology base that exists to move forward with a program leading to implementation of the Stratospheric Observatory for Infrared Astronomy (SOFIA).

  2. Astronomy with a home computer

    CERN Document Server

    Monks, Neale

    2005-01-01

    Here is a one-volume guide to just about everything computer-related for amateur astronomers! Today's amateur astronomy is inextricably linked to personal computers. Computer-controlled "go-to" telescopes are inexpensive. CCD and webcam imaging make intensive use of the technology for capturing and processing images. Planetarium software provides information and an easy interface for telescopes. The Internet offers links to other astronomers, information, and software. The list goes on and on. Find out here how to choose the best planetarium program: are commercial versions really better than freeware? Learn how to optimise a go-to telescope, or connect it to a lap-top. Discover how to choose the best webcam and use it with your telescope. Create a mosaic of the Moon, or high-resolution images of the planets... Astronomy with a Home Computer is designed for every amateur astronomer who owns a home computer, whether it is running Microsoft Windows, Mac O/S or Linux. It doesn't matter what kind of telescope you...

  3. Rescuing Middle School Astronomy

    Science.gov (United States)

    Mayo, L. A.; Janney, D.

    2010-12-01

    There is a crisis in education at the middle school level (Spellings, 2006). Recent studies point to large disparities in middle school performance in schools with high minority populations. The largest disparities exist in areas of math and science. Astronomy has a universal appeal for K-12 students but is rarely taught at the middle school level. When it is taught at all it is usually taught in isolation with few references in other classes such as other sciences (e.g. physics, biology, and chemistry), math, history, geography, music, art, or English. The problem is greatest in our most challenged school districts. With scores in reading and math below national averages in these schools and with most state achievement tests ignoring subjects like astronomy, there is little room in the school day to teach about the world outside our atmosphere. Add to this the exceedingly minimal training and education in astronomy that most middle school teachers have and it is a rare school that includes any astronomy teaching at all. In this presentation, we show how to develop and offer an astronomy education training program for middle school teachers encompassing a wide range of educational disciplines that are frequently taught at the middle school level. The prototype for this program was developed and launched in two of the most challenged and diverse school systems in the country; D.C. Public Schools, and Montgomery County (MD) Public Schools.

  4. Multichannel system for angular distribution measurements

    International Nuclear Information System (INIS)

    Burjan, V.; Kroha, V.; Putz, K.

    A description is given of the individual blocks of the spectrometric apparatus used for measuring the angular distribution of particle spectra and excitation functions of (d,p) reactions at an electrostatic accelerator and the U-120 M cyclotron, both operating at the Nuclear Physics Institute of the Czechoslovak Academy of Sciences at Rez. Main attention was devoted to attaining maximum energy resolution at a high measurement efficiency, this by installing 8 independent spectrometric chains allowing simultaneous measurement of angular distribution in 8 points of the beam. The semiconductor detectors were cooled to -40 degC to -60 degC, which significantly reduced the level of inherent detector noise. An energy resolution of 13 keV was attained using Tesla detectors at a particle energy of 11 MeV. A brief review of data processing and software is given. (B.S.)

  5. Astronomy in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Palouš, Jan; Hadrava, Petr

    -, č. 128 (2007), s. 3-3 ISSN 0722-6691 Institutional research plan: CEZ:AV0Z10030501 Keywords : astronomy * astropohysics * Czech republic Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  6. Astronomy in Australia

    Science.gov (United States)

    Watson, F.; Couch, W.

    2017-12-01

    Australians have watched the sky for tens of thousands of years. The nineteenth century saw the foundation of government observatories in capital cities such as Sydney and Melbourne. While early twentieth-century astronomy focused largely on solar physics, the advent of radio astronomy at the end of the Second World War enabled Australia to take a leading role in the new science, with particular emphasis on low-frequency studies. Today, the radio quietness of its outback interior provides an excellent location for the Australian core of the Square Kilometre Array. Australian optical astronomy has flourished since the 1960s, with the 3.9-metre Anglo-Australian Telescope becoming the principal national facility in 1974. Access to ESO’s facilities at the La Silla Paranal Observatory is warmly welcomed by all Australian astronomers.

  7. Submillimetre-wave astronomy

    International Nuclear Information System (INIS)

    Beckman, J.E.; Phillips, J.P.

    1982-01-01

    Observations in the 100-1000-micron band and the instruments used to obtain them are discussed in contributions to the Submillimeter Wave Astronomy Conference held at Queen Mary College, London, in September 1981. The major subject areas covered are large-scale structure and radiative transfer within interstellar clouds, spectroscopic observations of molecular sources, interstellar chemistry, and submillimeter (SM) instrumentation. Reports are included on the formation of giant cloud complexes, cool molecular clouds, models for hot-centered and externally heated clouds, dust in Bok globules, airborne FIR and SM spectroscopy, rotational transitions of CH3OH and NH2 near 1.2 mm, high-velocity flows and molecular jets, FIR emissions from late-type galaxies, ion-grain collisions as a source of interstellar molecules, bandpass filters for SM astronomy, the SM receiver of the future, HF techniques in heterodyne astronomy, and the mm-wave cosmic background

  8. Visualising Astronomy: "Other Worlds"

    Science.gov (United States)

    Wyatt, R.

    2009-02-01

    The infrastructures that are built and used for astronomical research are financed by - and therefore must be justified to - our society. Astronomy has an innate appeal for people of all ages, partly because it concerns the fascinating, great questions "of life, the Universe and everything" and partly because much of the data obtained with telescopes can be presented as objects of stunning beauty. These are key facts when considering communicating astronomy with the public. This native advantage that astronomy has over many other sciences does not, however, relieve us of the obligation to explain what we are doing to the public at large. There are many reasons for doing this. They range from attracting bright young people into the subject to fuel future research endeavours to convincing decision-takers to allocate large sums of money to finance increasingly expensive and ambitious projects.

  9. What next for astronomy?

    Science.gov (United States)

    Williams, Robert

    2009-12-01

    "Astronomy is in the midst of a golden age," wrote Catherine Cesarsky, my predecessor as president of the International Astronomical Union (IAU), earlier this year in Physics World (March pp22-24). I believe that is certainly true and it is an opportunity that we must take full advantage of. Astronomy is one of the great ways to bring science to the public - the images of the universe obtained using the Hubble Space Telescope, for example, are full of beauty. Astronomy is all about us. Indeed, the Earth and the life on it have developed from the cosmos, and the sky is the one laboratory that all humanity shares equally and that is accessible to all. There is little about the subject that appeals to fear - except, perhaps, the occasional killer asteroid. So what better science to inspire and educate people that what we do not know is definitely worth knowing?

  10. Teaching Astronomy Online

    Science.gov (United States)

    Radnofsky, Mary L.; Bobrowsky, Matthew

    This article is intended to provide an overview of the practical, pedagogical, and philosophical considerations in designing a Web-based astronomy course, and to demonstrate the educational benefits that such online courses can afford students. Because online students need to take more responsibility for their learning, faculty must make course expectations extremely clear. Online education allows for increased student participation and equal access to college by such groups as the military, the handicapped, full-time employees, and rural and senior citizens. Teaching the sciences online--especially astronomy--gives students more time to think critically about new information. This article also includes tools, checklists, and resources helpful for introducing faculty to online course development in astronomy.

  11. Orbital angular momentum light in microscopy.

    Science.gov (United States)

    Ritsch-Marte, Monika

    2017-02-28

    Light with a helical phase has had an impact on optical imaging, pushing the limits of resolution or sensitivity. Here, special emphasis will be given to classical light microscopy of phase samples and to Fourier filtering techniques with a helical phase profile, such as the spiral phase contrast technique in its many variants and areas of application.This article is part of the themed issue 'Optical orbital angular momentum'. © 2017 The Author(s).

  12. Angular momentum projected semiclassics

    International Nuclear Information System (INIS)

    Hasse, R.W.

    1986-10-01

    By using angular momentum projected plane waves as wave functions, we derive semiclassical expressions for the single-particle propagator, the partition function, the nonlocal density matrix, the single-particle density and the one particle- one hole level density for fixed angular momentum and fixed z-component or summed over the z-components. Other quantities can be deduced from the propagator. In coordinate space (r, r') the relevant quantities depend on vertical stroker - r 3 vertical stroke instead of vertical stroker - r'vertical stroke and in Wigner space (R, P) they become proportional to the angular momentum constraints δ(vertical strokeRxPvertical stroke/ℎ - l) and δ((RxP) z /ℎ - m). As applications we calculate the single-particle and one particle- one hole level densities for harmonic oscillator and Hill-Wheeler box potentials and the imaginary part of the optical potential and its volume integral with an underlying harmonic oscillator potential and a zero range two-body interaction. (orig.)

  13. Angular Momentum in Fission

    Science.gov (United States)

    Gönnenwein, F.; Bunakov, V.; Dorvaux, O.; Gagarski, A.; Guseva, I.; Hanappe, F.; Kadmensky, S.; von Kalben, J.; Khlebnikov, S.; Kinnard, V.; Kopatch, Yu.; Mutterer, M.; Nesvizhevsky, V.; Petrov, G.; Prokhorova, E.; Rubchenya, V.; Sillanpää, M.; Simpson, G.; Sokolov, V.; Soldner, T.; Stuttgé, L.; Tiourine, G.; Trzaska, W.; Tsekhanovich, I.; Wagemans, C.; Wollersheim, H.-J.; Zavarukhina, T.; Zimmer, O.

    2008-04-01

    Three novel experiments in spontaneous and thermal neutron induced fission all with a bearing on angular momentum in fission are reviewed. In the first experiment it was observed that, in the reaction 235U(n, f) with incident polarized cold neutrons, the nucleus undergoing scission is rotating. This was inferred from the shift in angular distributions of ternary particles being dependent on the orientation of neutron spin. In the second study the properties of the angular momentum of spherical fission fragments was investigated. Current theories trace the spin of fragments to their deformations allowing for collective rotational vibrations at scission. However, in particular the spherical 132Te isotope exhibits a large spin at variance with theory. Exploiting the specific properties of cold deformed fission it could be proven that, for 132Te, single particle excitations instead of collective modes are responsible for the large spin observed. In a third project a pilot study was exploring the possibility to search for an evaporation of neutrons from fragments being anisotropic in their own cm-system. Due to fragment spin this anisotropy is claimed since decades to exist. It was so far never observed. A scheme has been devised and tested were triple coincidences between a fragment and two neutrons are evaluated in a way to bring the cm-anisotropy into the foreground while getting rid of the kinematical anisotropy in the lab-system due to evaporation from moving fragments. The test was run for spontaneous fission of 252Cf.

  14. The Cambridge encyclopaedia of astronomy

    CERN Document Server

    1977-01-01

    Astronomy has been transformed in the last two decades by a series of dramatic discoveries that have left most reference books completely out of date. The Cambridge Encyclopaedia of Astronomy presents a broadly based survey of the whole of astronomy which places emphasis on these critical new findings.

  15. School-Based Extracurricular Astronomy

    Science.gov (United States)

    Stanger, Jeffrey J.

    2010-01-01

    The International Year of Astronomy in 2009 focused considerable public attention on Astronomy and generated valuable resources for educators. These activities are an effective vehicle for promoting Science to students and to the wider school community. The most engaging practical astronomy activities are best delivered with sustained support from…

  16. Teaching Astronomy in UK Schools

    Science.gov (United States)

    Roche, Paul; Roberts, Sarah; Newsam, Andy; Barclay, Charles

    2012-01-01

    This article attempts to summarise the good, bad and (occasionally) ugly aspects of teaching astronomy in UK schools. It covers the most common problems reported by teachers when asked about covering the astronomy/space topics in school. Particular focus is given to the GCSE Astronomy qualification offered by Edexcel (which is currently the…

  17. Quickly Creating Interactive Astronomy Illustrations

    Science.gov (United States)

    Slater, Timothy F.

    2015-01-01

    An innate advantage for astronomy teachers is having numerous breathtaking images of the cosmos available to capture students' curiosity, imagination, and wonder. Internet-based astronomy image libraries are numerous and easy to navigate. The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Planetary…

  18. Astronomy posters. Abstracts.

    Science.gov (United States)

    van Woerden, H.

    Contents: IAU Symposia Nos. 164: Stellar populations. 165: Compact stars in binaries. 166: Astronomical and astrophysical objectives of sub-milliarcsecond optical astrometry. 167: New developments in array technology and applications. 168: Examining the Big Bang and diffuse background radiations. 169: Unsolved problems of the Milky Way. Joint Discussions Nos. 1: Gas disks in galaxies. 2: Origin and detection of planetary systems. 3: Helio- and asteroseismology. 4: Current developments in astronomy education. 5: Activity in the central parts of galaxies. 6: Sun and heliosphere - challenges for solar-terrestrial physics, magneto- and hydrodynamics. 7: History of astronomy. 8: Time scales - state of the art. 9: Women in astronomy. 10: Extragalactic planetary nebulae. 11: Stellar and interstellar lithium and primordial nucleosynthesis. 12: Accuracy of the HR diagram and related parameters. 13: Recent advances in convection theory and modelling. 14: Towards the establishment of the astronomical standards. 15: Statistical evaluation of astronomical time series. 16: Astrophysical applications of powerful new atomic databases. 17: Dust around young stars: How related to solar system dust? 18: Solar system radar observations. 19: Nutation. 20: The status of archiving astronomical data. Working Groups Nos. 1: Problems of astronomy in Africa. 2: Near-Earth objects detection. 3: International catalog projects. 4: Asteroids and comets.

  19. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2013-01-01

    This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

  20. Teaching Astronomy Using Tracker

    Science.gov (United States)

    Belloni, Mario; Christian, Wolfgang; Brown, Douglas

    2013-01-01

    A recent paper in this journal presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses. Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In…

  1. The Cost of Astronomy

    DEFF Research Database (Denmark)

    Dorch, Bertil F.

    Using Scopus and national sources, I have investigated the evolution of the cost of publishing in Danish astronomy on a fine scale over a number of years. I find that the number of publications per year from Danish astronomers increased by a factor of four during 15 years: naturally, the correspo......Using Scopus and national sources, I have investigated the evolution of the cost of publishing in Danish astronomy on a fine scale over a number of years. I find that the number of publications per year from Danish astronomers increased by a factor of four during 15 years: naturally......, the corresponding potential cost of publishing must have increased similarly. The actual realized cost of publishing in core journals are investigated for a high profile Danish astronomy research institutions. I argue that the situation is highly unstable if the current cost scenario continues, and I speculate...... that Danish astronomy is risking a scholarly communication collapse due to the combination of increasing subscription cost, increased research output, and increased direct publishing costs related to Open access and other page charges....

  2. Gamma ray astronomy

    International Nuclear Information System (INIS)

    Hillier, R.

    1984-01-01

    The book reviews the development of gamma ray astronomy over the past twenty five years. A large section of the book is devoted to the problems of background radiation and the design of detectors. Gamma rays from the sun, the galactic disc, the galaxy, and extra galactic sources; are also discussed. (U.K.)

  3. Gravitational-Wave Astronomy

    Indian Academy of Sciences (India)

    We present a broad overview of the emerging field of gravitational-wave astronomy. Although gravitational waves have not been directly de- tected yet, the worldwide scientific community is engaged in an exciting search for these elusive waves. Once detected, they will open up a new observational window to the Universe.

  4. Division x: Radio Astronomy

    NARCIS (Netherlands)

    Taylor, Russ; Chapman, Jessica; Rendong, Nan; Carilli, Christopher; Giovannini, Gabriele; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin; Lazio, Joseph; Morganti, Raffaella; Rubio, Monica; Shastri, Prajval

    This triennium has seen a phenomenal investment in development of observational radio astronomy facilities in all parts of the globe at a scale that significantly impacts the international community. This includes both major enhancements such as the transition from the VLA to the EVLA in North

  5. Colonial American Astronomy

    Science.gov (United States)

    Yeomans, Donald K.

    2007-12-01

    While a foundation of German scientific methods enabled the rapid growth of North American Astronomy in the nineteenth century, during the seventeenth and most of the eighteenth centuries, the colonial men of science looked only to the English mother country for scientific patronage and guidance. An essay on fundamental astronomy appeared in one of the annual colonial almanacs as early as 1656, telescopic observations were made about 1660 and the first original colonial astronomical work was published by Thomas Danforth on the comet of 1664. By 1671 the Copernican ideas were so espoused at Harvard College that a physics class refused to read a Ptolemaic textbook when it was assigned to them by a senior instructor. At least in the Cambridge-Boston area, contemporary colonialist had access to the most recent scientific publications from the mother country. Observations of the great comet of 1680 by the Almanac maker, John Foster, reached Isaac Newton and were used and gratefully acknowledged in his Principia. During the seventeenth century the colonial interest in astronomy was more intense than it was for other sciences but colonists still occupied a position in the scientific backwater when compared with contemporary European scientists. Nevertheless, the science of astronomy was successfully transplanted from England to North America in the seventeenth century.

  6. Outreach Testing of Ancient Astronomy

    Science.gov (United States)

    Sanmartin, J. R. S.; Blanco, M. B. M.

    2015-10-01

    This work is an outreach approach to an ubiquitous recent problem in secondary-school education: how to face back the decreasing interest in natural sciences shown by students under 'pressure' of convenient resources in digital devices/applications. The approach rests on two features. First, empowering of teen-age students to understand regular natural events around, as very few educated people they meet could do. Secondly, an understanding that rests on personal capability to test and verify experimental results from the oldest science, astronomy, with simple instruments as used from antiquity down to the Renaissance (a capability restricted to just solar and lunar motions). Because lengths in astronomy and daily life are so disparate, astronomy basically involved observing and registering values of angles (along with times), measurements being of two types, of angles on the ground and of angles in space, from the ground. First, the gnomon, a simple vertical stick introduced in Babylonia and Egypt, and then in Greece, is used to understand solar motion. The gnomon shadow turns around during any given day, varying in length and thus angle between solar ray and vertical as it turns, going through a minimum (noon time, at a meridian direction) while sweeping some angular range from sunrise to sunset. Further, the shadow minimum length varies through the year, with times when shortest and sun closest to vertical, at summer solstice, and times when longest, at winter solstice six months later. The extreme directions at sunset and sunrise correspond to the solstices, swept angular range greatest at summer, over 180 degrees, and the opposite at winter, with less daytime hours; in between, spring and fall equinoxes occur, marked by collinear shadow directions at sunrise and sunset. The gnomon allows students to determine, in addition to latitude (about 40.4° North at Madrid, say), the inclination of earth equator to plane of its orbit around the sun (ecliptic), this

  7. Optical angular momentum and atoms.

    Science.gov (United States)

    Franke-Arnold, Sonja

    2017-02-28

    Any coherent interaction of light and atoms needs to conserve energy, linear momentum and angular momentum. What happens to an atom's angular momentum if it encounters light that carries orbital angular momentum (OAM)? This is a particularly intriguing question as the angular momentum of atoms is quantized, incorporating the intrinsic spin angular momentum of the individual electrons as well as the OAM associated with their spatial distribution. In addition, a mechanical angular momentum can arise from the rotation of the entire atom, which for very cold atoms is also quantized. Atoms therefore allow us to probe and access the quantum properties of light's OAM, aiding our fundamental understanding of light-matter interactions, and moreover, allowing us to construct OAM-based applications, including quantum memories, frequency converters for shaped light and OAM-based sensors.This article is part of the themed issue 'Optical orbital angular momentum'. © 2017 The Author(s).

  8. Strategies for Teaching Astronomy

    Science.gov (United States)

    Bennett, J.

    2000-12-01

    No matter whether you are teaching school children, undergraduates, or colleagues, a few key strategies are always useful. I will present and give examples for the following five key strategies for teaching astronomy. 1. Provide a Contextual Framework: It is much easier to learn new facts or concepts if they can be ``binned" into some kind of pre-existing mental framework. Unless your listeners are already familiar with the basic ideas of modern astronomy (such as the hierarchy of structure in the universe, the scale of the universe, and the origin of the universe), you must provide this before going into the details of how we've developed this modern picture through history. 2. Create Conditions for Conceptual Change: Many people hold misconceptions about astronomical ideas. Therefore we cannot teach them the correct ideas unless we first help them unlearn their prior misconceptions. 3. Make the Material Relevant: It's human nature to be more interested in subjects that seem relevant to our lives. Therefore we must always show students the many connections between astronomy and their personal concerns, such as emphasizing how we are ``star stuff" (in the words of Carl Sagan), how studying other planets helps us understand our own, and so on. 4. Limit Use of Jargon: The number of new terms in many introductory astronomy books is larger than the number of words taught in many first courses in foreign language. This means the books are essentially teaching astronomy in a foreign language, which is a clear recipe for failure. We must find ways to replace jargon with plain language. 5. Challenge Your Students: Don't dumb your teaching down; by and large, students will rise to meet your expectations, as long as you follow the other strategies and practice good teaching.

  9. AngularJS directives

    CERN Document Server

    Vanston, Alex

    2013-01-01

    This book uses a practical, step-by-step approach, starting with how to build directives from the ground up before moving on to creating web applications comprised of multiple modules all working together to provide the best user experience possible.This book is intended for intermediate JavaScript developers who are looking to enhance their understanding of single-page web application development with a focus on AngularJS and the JavaScript MVC frameworks.It is expected that readers will understand basic JavaScript patterns and idioms and can recognize JSON formatted data.

  10. On the angular momentum in star formation

    International Nuclear Information System (INIS)

    Horedt, G.P.

    1978-01-01

    The author discusses the rotation of interstellar clouds which are in a stage immediately before star formation. Cloud collisions seem to be the principal cause of the observed rotation of interstellar clouds. The rotational motion of the clouds is strongly influenced by turbulence. Theories dealing with the resolution of the angular momentum problem in star formation are classified into five major groups. The old idea that the angular momentum of an interstellar cloud passes during star formation into the angular momentum of double star systems and/or circumstellar clouds, is developed. It is suggested that a rotating gas cloud contracts into a ring-like structure which fragments into self-gravitating subcondensations. By collisions and gas accretion these subcondensations accrete into binary systems surrounded by circumstellar clouds. Using some rough approximations the authors find analytical expressions for the semi-major axis of the binary system and for the density of the circumstellar clouds as a function of the initial density and of the initial angular velocity of an interstellar cloud. The obtained values are well within the observational limits. (Auth.)

  11. Angular Distribution of GRBs

    Directory of Open Access Journals (Sweden)

    L. G. Balázs

    2012-01-01

    Full Text Available We studied the complete randomness of the angular distribution of BATSE gamma-ray bursts (GRBs. Based on their durations and peak fluxes, we divided the BATSE sample into 5 subsamples (short1, short2, intermediate, long1, long2 and studied the angular distributions separately. We used three methods to search for non-randomness in the subsamples: Voronoi tesselation, minimal spanning tree, and multifractal spectra. To study any non-randomness in the subsamples we defined 13 test-variables (9 from Voronoi tesselation, 3 from the minimal spanning tree and one from the multifractal spectrum. We made Monte Carlo simulations taking into account the BATSE’s sky-exposure function. We tested therandomness by introducing squared Euclidean distances in the parameter space of the test-variables. We recognized that the short1, short2 groups deviate significantly (99.90%, 99.98% from the fully random case in the distribution of the squared Euclidean distances but this is not true for the long samples. In the intermediate group, the squared Euclidean distances also give significant deviation (98.51%.

  12. Active x-ray optics for high resolution space telescopes

    Science.gov (United States)

    Doel, Peter; Atkins, Carolyn; Brooks, D.; Feldman, Charlotte; Willingale, Richard; Button, Tim; Rodriguez Sanmartin, Daniel; Meggs, Carl; James, Ady; Willis, Graham; Smith, Andy

    2017-11-01

    The Smart X-ray Optics (SXO) Basic Technology project started in April 2006 and will end in October 2010. The aim is to develop new technologies in the field of X-ray focusing, in particular the application of active and adaptive optics. While very major advances have been made in active/adaptive astronomical optics for visible light, little was previously achieved for X-ray optics where the technological challenges differ because of the much shorter wavelengths involved. The field of X-ray astronomy has been characterized by the development and launch of ever larger observatories with the culmination in the European Space Agency's XMM-Newton and NASA's Chandra missions which are currently operational. XMM-Newton uses a multi-nested structure to provide modest angular resolution ( 10 arcsec) but large effective area, while Chandra sacrifices effective area to achieve the optical stability necessary to provide sub-arc second resolution. Currently the European Space Agency (ESA) is engaged in studies of the next generation of X-ray space observatories, with the aim of producing telescopes with increased sensitivity and resolution. To achieve these aims several telescopes have been proposed, for example ESA and NASA's combined International X-ray Observatory (IXO), aimed at spectroscopy, and NASA's Generation-X. In the field of X-ray astronomy sub 0.2 arcsecond resolution with high efficiency would be very exciting. Such resolution is unlikely to be achieved by anything other than an active system. The benefits of a such a high resolution would be important for a range of astrophysics subjects, for example the potential angular resolution offered by active X-ray optics could provide unprecedented structural imaging detail of the Solar Wind bowshock interaction of comets, planets and similar objects and auroral phenomena throughout the Solar system using an observing platform in low Earth orbit. A major aim of the SXO project was to investigate the production of thin

  13. Using the Teach Astronomy Website to Enrich Introductory Astronomy Classes

    Science.gov (United States)

    Hardegree-Ullman, K. K.; Impey, C. D.; Patikkal, A.; Austin, C. L.

    2013-04-01

    This year we implemented Teach Astronomy as a free online resource to be used as a teaching tool for non-science major astronomy courses and for a general audience interested in the subject. The comprehensive astronomy content of the website includes: an introductory text book, encyclopedia articles, images, two to three minute topical video clips, podcasts, and news articles. Teach Astronomy utilizes a novel technology to cluster, display, and navigate search results, called a Wikimap. We will present an overview of how Teach Astronomy works and how instructors can use it as an effective teaching tool in the classroom. Additionally, we will gather feedback from science instructors on how to improve the features and functionality of the website, as well as develop new assignment ideas using Teach Astronomy.

  14. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2009-01-01

    The recent years have seen breathtaking progress in technology, especially in the receiver and digital technologies relevant for radio astronomy, which has at the same time advanced to shorter wavelengths. This is the updated and completely revised 5th edition of the most used introductory text in radio astronomy. It presents a unified treatment of the entire field from centimeter to sub-millimeter wavelengths. Topics covered include instruments, sensitivity considerations, observational methods and interpretations of the data recorded with both single dishes and interferometers. This text is useful to both students and experienced practicing astronomers. Besides making major updates and additions throughout the book, the authors have re-organized a number of chapters to more clearly separate basic theory from rapidly evolving practical aspects. Further, problem sets have been added at the end of each chapter.

  15. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Setti, G.

    1980-01-01

    This book contains the lectures, and the most important seminars held at the NATO meeting on X-Ray astronomy in Erice, July 1979. The meeting was an opportune forum to discuss the results of the first 8-months of operation of the X-ray satellite, HEAO-2 (Einstein Observatory) which was launched at the end of 1978. Besides surveying these results, the meeting covered extragalactic astronomy, including the relevant observations obtained in other portions of the electromagnetic spectrum (ultra-violet, optical, infrared and radio). The discussion on galactic X-ray sources essentially covered classical binaries, globular clusters and bursters and its significance to extragalactic sources and to high energy astrophysics was borne in mind. (orig.)

  16. Astronomy and astrology

    Science.gov (United States)

    Zarka, Philippe

    2011-06-01

    Astrology meets a large success in our societies, from the private to the political sphere as well as in the media, in spite of the demonstrated inaccuracy of its psychological as well as operational predictions. We analyse here the relations between astrology and astronomy, as well as the criticisms opposed by the latter to the former. We show that most of these criticisms are weak. Much stronger ones emerge from the analysis of the astrological practice compared to the scientific method, leading us to conclude to the non-scientificity of astrology. Then we return to the success of astrology, and from its analysis we propose a renewed (and prophylactic) rôle for astronomy in society.

  17. Artificial Intelligence in Astronomy

    Science.gov (United States)

    Devinney, E. J.; Prša, A.; Guinan, E. F.; Degeorge, M.

    2010-12-01

    From the perspective (and bias) as Eclipsing Binary researchers, we give a brief overview of the development of Artificial Intelligence (AI) applications, describe major application areas of AI in astronomy, and illustrate the power of an AI approach in an application developed under the EBAI (Eclipsing Binaries via Artificial Intelligence) project, which employs Artificial Neural Network technology for estimating light curve solution parameters of eclipsing binary systems.

  18. Astronomy on a Landfill

    Science.gov (United States)

    Venner, Laura

    2008-09-01

    Engaging "K-to-Gray” audiences (children, families, and older adults) in astronomical activities is one of the main goals of the NJMC Center for Environmental and Scientific Education and the William D. McDowell Observatory located in Lyndhurst, NJ. Perched atop a closed and reclaimed municipal solid waste landfill, our new LEED - certified building (certification pending) and William D. McDowell observatory will assist in bringing the goals of IYA 2009 to the approximately 25,000 students and 15,000 adults that visit our site from the NY/NJ region each year. Diversifying our traditional environmental science offerings, we have incorporated astronomy into our repertoire with "The Sun Through Time” module, which includes storytelling, cultural astronomy, telescope anatomy, and other activities that are based on the electromagnetic spectrum and our current knowledge of the sun. These lessons have also been modified to bring astronomy to underserved communities, specifically those individuals that have dexterity or cognitive ability differences. The program is conducted in a classroom setting and is designed to meet New Jersey Core Curriculum Content Standards. With the installation of our new 20” telescope, students and amateur astronomers will be given the opportunity to perform rudimentary research. In addition, a program is in development that will allow individuals to measure local sky brightness and understand the effects of light pollution on astronomical viewing. Teaching astronomy in an urban setting presents many challenges. All individuals, regardless of ability level or location, should be given the opportunity to be exposed to the wonders of the universe and the MEC/CESE has been successful in providing those opportunities.

  19. Gravitational Wave Astronomy

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Gravitational wave astronomy is expected to become an observational field within the next decade. First direct detection of gravitational waves is possible with existing terrestrial-based detectors, and highly probable with proposed upgrades. In this three-part lecture series, we give an overview of the field, including material on gravitional wave sources, detection methods, some details of interferometric detectors, data analysis methods, and current results from observational data-taking runs of the LIGO and GEO projects.

  20. Software systems for astronomy

    CERN Document Server

    Conrad, Albert R

    2014-01-01

    This book covers the use and development of software for astronomy. It describes the control systems used to point the telescope and operate its cameras and spectrographs, as well as the web-based tools used to plan those observations. In addition, the book also covers the analysis and archiving of astronomical data once it has been acquired. Readers will learn about existing software tools and packages, develop their own software tools, and analyze real data sets.

  1. Syllabus Computer in Astronomy

    Science.gov (United States)

    Hojaev, Alisher S.

    2015-08-01

    One of the most important and actual subjects and training courses in the curricula for undergraduate level students at the National university of Uzbekistan is ‘Computer Methods in Astronomy’. It covers two semesters and includes both lecture and practice classes. Based on the long term experience we prepared the tutorial for students which contain the description of modern computer applications in astronomy.The main directions of computer application in field of astronomy briefly as follows:1) Automating the process of observation, data acquisition and processing2) Create and store databases (the results of observations, experiments and theoretical calculations) their generalization, classification and cataloging, working with large databases3) The decisions of the theoretical problems (physical modeling, mathematical modeling of astronomical objects and phenomena, derivation of model parameters to obtain a solution of the corresponding equations, numerical simulations), appropriate software creation4) The utilization in the educational process (e-text books, presentations, virtual labs, remote education, testing), amateur astronomy and popularization of the science5) The use as a means of communication and data transfer, research result presenting and dissemination (web-journals), the creation of a virtual information system (local and global computer networks).During the classes the special attention is drawn on the practical training and individual work of students including the independent one.

  2. Current Status of the IAU Working Group for Numerical Standards of Fundamental Astronomy

    National Research Council Canada - National Science Library

    Luzum, B; Capitaine, N; Fienga, A; Folkner, W; Fukushima, T; Hilton, J; Hohenkerk, C; Krasinsky, G; Petit, G; Pitjeva, E; Soffel, M; Wallace, P

    2007-01-01

    ...) for Numerical Standards of Fundamental Astronomy. The goal of the WG are to update "IAU Current Best Estimates" conforming with IAU Resolutions, the International Earth Rotation and Reference System Service (IERS...

  3. Transmission of Babylonian Astronomy to Other Cultures

    Science.gov (United States)

    Jones, Alexander

    Babylonian astronomy and astrology were extensively transmitted to other civilizations in the second and first millennia BC. Greek astronomy in particular was largely shaped by knowledge of Babylonian observations and mathematical astronomy.

  4. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Therefore, multiwaveband observational efforts with wide fields of view will be the key to progress of transients astronomy from the middle 2020s offering unprecedented deep images and high spatial and spectral resolutions. Radio observations of Gamma Ray Bursts (GRBs) with SKA will uncover not only much fainter ...

  5. Terahertz heterodyne technology for astronomy and planetary science

    NARCIS (Netherlands)

    Wild, Wolfgang

    2007-01-01

    Heterodyne detection techniques play an important role in high-resolution spectroscopy in astronomy and planetary science. In particular, heterodyne technology in the Terahertz range has rapidly evolved in recent years. Cryogenically cooled receivers approaching quantum-limited sensitivity have been

  6. Explosive and Radio-Selected Transients: Transient Astronomy with ...

    Indian Academy of Sciences (India)

    Therefore, multiwaveband observational efforts with wide fields of view will be the key to progress of transients astronomy from the middle 2020s offering unprecedented deep images and high spatial and spectral resolutions. Radio observations of Gamma Ray Bursts (GRBs) with SKA will uncover not only much fainter ...

  7. Use of the maximum entropy method in X-ray astronomy

    International Nuclear Information System (INIS)

    Willingale, R.

    1981-01-01

    An algorithm used to apply the maximum entropy method in X-ray astronomy is described. It is easy to programme on a digital computer and fast enough to allow processing of two-dimensional images. The method gives good noise suppression without loss of instrumental resolution and has been successfully applied to several data analysis problems in X-ray astronomy. The restoration of a high-resolution image from the Einstein Observatory demonstrates the use of the algorithm. (author)

  8. Angular integrals in d dimensions

    International Nuclear Information System (INIS)

    Somogyi, Gabor

    2011-01-01

    We discuss the evaluation of certain d dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly consider some applications. (orig.)

  9. Astronomy across cultures the history of non-Western astronomy

    CERN Document Server

    Xiaochun, Sun

    2000-01-01

    Astronomy Across Cultures: A History of Non-Western Astronomy consists of essays dealing with the astronomical knowledge and beliefs of cultures outside the United States and Europe. In addition to articles surveying Islamic, Chinese, Native American, Aboriginal Australian, Polynesian, Egyptian and Tibetan astronomy, among others, the book includes essays on Sky Tales and Why We Tell Them and Astronomy and Prehistory, and Astronomy and Astrology. The essays address the connections between science and culture and relate astronomical practices to the cultures which produced them. Each essay is well illustrated and contains an extensive bibliography. Because the geographic range is global, the book fills a gap in both the history of science and in cultural studies. It should find a place on the bookshelves of advanced undergraduate students, graduate students, and scholars, as well as in libraries serving those groups.

  10. Dyslexia and Astronomy

    Science.gov (United States)

    Schneps, Matthew H.; Greenhill, L. J.; Rose, L. T.

    2007-12-01

    Dyslexia is a hereditary neurological disability that impairs reading. It is believed that anywhere from 5% to 20% of all people in the US may have dyslexia to a greater or lesser degree. Though dyslexia is common, it is a "silent disability" in the sense that it is not easy to tell which individuals suffer from dyslexia and which do not. There is a substantial body of evidence to suggest that people with dyslexia tend to do well in science. For example, Baruj Benacerraf, a Nobel laureate in medicine, is among those whose impairments have been documented and studied. Given that dyslexia was not diagnosed in schools prior to the late 1970's, many established science researchers may have dyslexia and be unaware of their impairment. Therefore, it would not be surprising to find that substantial numbers of scientists working in the fields of astronomy and astrophysics have dyslexia, and yet be unaware of the effects this disability has had on their research. A recently proposed theory by the authors suggests that there may be specific neurological reasons why those with dyslexia may be predisposed to science, and predicts that dyslexia may be associated with enhanced abilities for certain types of visual processing, with special implications for image processing. Our study, funded by the NSF, investigates this hypothesis in the context of astronomy and astrophysics. We expect this work will uncover and document challenges faced by scientists with dyslexia, but perhaps more importantly, lead to an understanding of the strengths these scientists bring to research. The program will serve as a clearing-house of information for scientists and students with dyslexia, and begin to provide mentoring for young people with dyslexia interested in astronomy. Scientists who have reason to believe they may have dyslexia are encouraged to contact the authors.

  11. Astrology as Cultural Astronomy

    Science.gov (United States)

    Campion, Nicholas

    The practice of astrology can be traced in most if not all human societies, in most time periods. Astrology has prehistoric origins and flourishes in the modern world, where it may be understood as a form of ethnoastronomy - astronomy practiced by the people. The Western tradition, which originated in Mesopotamia and was developed in the Greek world, has been most studied by academics. However, India is also home to a tradition which has survived in a continuous lineage for 2,000 years. Complex systems of astrology also developed in China and Mesoamerica, while all other human societies appear to seek social and religious meaning in the stars.

  12. Gravitational-Wave Astronomy

    Science.gov (United States)

    Kelly, Bernard J.

    2010-01-01

    Einstein's General Theory of Relativity is our best classical description of gravity, and informs modern astronomy and astrophysics at all scales: stellar, galactic, and cosmological. Among its surprising predictions is the existence of gravitational waves -- ripples in space-time that carry energy and momentum away from strongly interacting gravitating sources. In my talk, I will give an overview of the properties of this radiation, recent breakthroughs in computational physics allowing us to calculate the waveforms from galactic mergers, and the prospect of direct observation with interferometric detectors such as LIGO and LISA.

  13. Astronomy in the classroom

    Science.gov (United States)

    Moiteiro, Bárbara; Rodrigues, Berta

    2016-04-01

    The motivation of young students to science is much higher when the theoretical teaching is accompanied by practice and these are engaged in activities that involve real problems of their society and requiring a scientific basis for its discussion. Several activities such as collaboration on current scientific experiments, direct contact with scientists, participation in science competitions, visits to Science Museums, artistic and craft activities, the use of simulators and virtual laboratories, increase the degree of student satisfaction and motivate them in their learning processes. This poster shows some of Astronomy activities with students of schools Agrupamento de Escolas José Belchior Viegas within the Physics and Chemistry classes.

  14. Expanding radio astronomy in Africa

    International Nuclear Information System (INIS)

    Gaylard, M J

    2013-01-01

    The Square Kilometre Array (SKA) Organisation announced in May 2012 that its members had agreed on a dual site solution for the SKA [1]. South Africa's bid for hosting the SKA has caused a ramp up of radio astronomy in Africa. To develop technology towards the SKA, the South African SKA Project (SKA SA) built a protoype radio telescope in 2007, followed in 2010 the seven antenna Karoo Array Telescope (KAT-7). Next is the 64 antenna MeerKAT, which will merge into SKA Phase 1 in Africa. As SKA Phase 2 is intended to add a high resolution capability with baselines out to 3000 km, the SKA SA brought in partner countries in Africa to host outstations. South Africa has been working with the partners to build capacity to operate the SKA and to benefit from it. The SA Department of Science and Technology (DST) developed a proposal to establish radio telescopes in the partner countries to provide hands-on learning and a capability for Very Long Baseline Interferometry (VLBI) research. Redundant 30 m class satellite antennas are being incorporated in this project.

  15. Science and Mathematics in Astronomy

    Science.gov (United States)

    Woolack, Edward

    2009-01-01

    A brief historical introduction to the development of observational astronomy will be presented. The close historical relationship between the successful application of mathematical concepts and advances in astronomy will be presented. A variety of simple physical demonstrations, hands-on group activities, and puzzles will be used to understand how the properties of light can be used to understand the contents of our universe.

  16. Making Astronomy Accessible

    Science.gov (United States)

    Grice, Noreen A.

    2011-05-01

    A new semester begins, and your students enter the classroom for the first time. You notice a student sitting in a wheelchair or walking with assistance from a cane. Maybe you see a student with a guide dog or carrying a Braille computer. Another student gestures "hello” but then continues hand motions, and you realize the person is actually signing. You wonder why another student is using an electronic device to speak. Think this can't happen in your class? According to the U.S. Census, one out of every five Americans has a disability. And some disabilities, such as autism, dyslexia and arthritis, are considered "invisible” disabilities. This means you have a high probability that one of your students will have a disability. As an astronomy instructor, you have the opportunity to reach a wide variety of learners by using creative teaching strategies. I will share some suggestions on how to make astronomy and your part of the universe more accessible for everyone.

  17. Challenges in Astronomy Education

    Science.gov (United States)

    De Greve, Jean-Pierre

    2010-11-01

    Astronomy is an attractive subject for education. It deals with fascination of the unknown and the unreachable, yet is uses tools, concepts and insights from various fundamental sciences such as mathematics, physics, chemistry, biology. Because of this it can be well used for introducing sciences to young people and to raise their interest in further studies in that direction. It is also an interesting subject for teaching as its different aspects (observation techniques, theory, data sampling and analysis, modelling,?) offer various didactical approaches towards different levels of pupils, students and different backgrounds. And it gives great opportunities to teach and demonstrate the essence of scientific research, through tutorials and projects. In this paper we discuss some of the challenges education in general, and astronomy in particular, faces in the coming decades, given the major geophysical and technological changes that can be deducted from our present knowledge. This defines a general, but very important background in terms of educational needs at various levels, and in geographical distribution of future efforts of the astronomical community. Special emphasis will be given to creative approaches to teaching, to strategies that are successful (such as the use of tutorials with element from computer games), and to initiatives complementary to the regular educational system. The programs developed by the IAU will be briefly highlighted.

  18. Classics in radio astronomy

    CERN Document Server

    Sullivan, Woodruff Turner

    1982-01-01

    Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave­ lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro­ ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of re...

  19. The Astronomy Workshop

    Science.gov (United States)

    Hamilton, Douglas P.

    2012-05-01

    {\\bf The Astronomy Workshop} (http://janus.astro.umd.edu) is a collection of interactive online educational tools developed for use by students, educators, professional astronomers, and the general public. The more than 20 tools in the Astronomy workshop are rated for ease-of-use, and have been extensively tested in large university survey courses as well as more specialized classes for undergraduate majors and graduate students. Here we briefly describe a few of the available tools. {\\bf Solar Systems Visualizer}: The orbital motions of planets, moons, and asteroids in the Solar System as well as many of the planets in exoplanetary systems are animated at their correct relative speeds in accurate to-scale drawings. Zoom in from the chaotic outer satellite systems of the giant planets all the way to their innermost ring systems. {\\bf Solar System Calculators}: These tools calculate a user-defined mathematical expression simultaneously for all of the Solar System's planets (Planetary Calculator) or moons (Satellite Calculator). Key physical and orbital data are automatically accessed as needed. {\\bf Stellar Evolution}: The "Life of the Sun" tool animates the history of the Sun as a movie, showing students how the size and color of our star has evolved and will evolve over billions of years. In "Star Race," the user selects two stars of different masses and watches their evolution in a split-screeen format that emphasizes the great differences in stellar lifetimes and fates.

  20. Ancient Astronomy in Armenia

    Science.gov (United States)

    Parsamian, Elma S.

    2007-08-01

    The most important discovery, which enriched our knowledge of ancient astronomy in Armenia, was the complex of platforms for astronomical observations on the Small Hill of Metzamor, which may be called an ancient “observatory”. Investigations on that Hill show that the ancient inhabitants of the Armenian Highlands have left us not only pictures of celestial bodies, but a very ancient complex of platforms for observing the sky. Among the ancient monuments in Armenia there is a megalithic monument, probably, being connected with astronomy. 250km South-East of Yerevan there is a structure Zorats Kar (Karahunge) dating back to II millennium B.C. Vertical megaliths many of which are more than two meters high form stone rings resembling ancient stone monuments - henges in Great Britain and Brittany. Medieval observations of comets and novas by data in ancient Armenian manuscripts are found. In the collection of ancient Armenian manuscripts (Matenadaran) in Yerevan there are many manuscripts with information about observations of astronomical events as: solar and lunar eclipses, comets and novas, bolides and meteorites etc. in medieval Armenia.

  1. Active Astronomy Roadshow Haiti

    Science.gov (United States)

    Laycock, Silas; Oram, Kathleen; Alabre, Dayana; Douyon, Ralph; UMass Lowell Haiti Development Studies Center

    2016-01-01

    College-age Haitian students working with advisors and volunteers from UMass Lowell in 2015 developed and tested an activity-based K-8 curriculum in astronomy, space, and earth science. Our partner school is located in Les Cayes, Haiti a city where only 65% of children attend school, and only half of those will complete 6th grade. Astronomy provides an accessible and non-intimidating entry into science, and activity-based learning contrasts with the predominant traditional teaching techniques in use in Haiti, to reach and inspire a different cohort of learners. Teachers are predominantly women in Haiti, so part of the effort involves connecting them with scientists, engineers and teacher peers in the US. As a developing nation, it is vital for Haitian (as for all) children to grow up viewing women as leaders in science. Meanwhile in the US, few are aware of the reality of getting an education in a 3rd world nation (i.e. most of the world), so we also joined with teachers in Massachusetts to give US school children a peek at what daily life is like for their peers living in our vibrant but impoverished neighbor. Our Haitian partners are committed to helping their sister-schools with curriculum and educator workshops, so that the overall quality of education can rise, and not be limited to the very few schools with access to resources. We will describe the activites, motivation, and and the lessons learned from our first year of the project.

  2. AngularJS testing cookbook

    CERN Document Server

    Bailey, Simon

    2015-01-01

    This book is intended for developers who have an understanding of the basic principles behind both AngularJS and test-driven development. You, as a developer, are interested in eliminating the fear related to either introducing tests to an existing codebase or starting out testing on a fresh AngularJS application. If you're a team leader or part of a QA team with the responsibility of ensuring full test coverage of an application, then this book is ideal for you to comprehend the full testing scope required by your developers. Whether you're new to or are well versed with AngularJS, this book

  3. High-Contrast Observations in Optical and Infrared Astronomy

    OpenAIRE

    Oppenheimer, Ben R.; Hinkley, Sasha

    2009-01-01

    High-contrast observations in optical and infrared astronomy are defined as any observation requiring a technique to reveal a celestial object of interest that is in such close angular proximity to another source brighter by a factor of at least 10^5 that optical effects hinder or prevent the collection of photons directly from the target of observation. This is a relatively new type of observation that enables research on previously obscured parts of the Universe. In particular, it is most a...

  4. Lidar Orbital Angular Momentum Sensor

    Data.gov (United States)

    National Aeronautics and Space Administration — The recognition in recent decades that electromagnetic fields have angular momentum (AM) in the form of not only polarization (or spin AM) but also orbital (OAM) has...

  5. Angular momentum from tidal torques

    International Nuclear Information System (INIS)

    Barnes, J.; Efstathiou, G.; Cambridge Univ., England)

    1987-01-01

    The origin of the angular momentum of bound objects in large N-body simulations is studied using three sets of models. One model with white-noise initial conditions is analyzed as well as two in which the initial conditions have more power on large scales, as predicted in models with cold dark matter. The growth and distribution of angular momentum in individual objects is studied and it is found that the specific angular momentum distribution of bound clumps increases in a near linear fashion with radius while the orientation of the angular momentum in the inner high-density regions is often poorly correlated with that of the outer parts. It is also found that the dimensionless spin parameter is insensitive to the initial perturbation spectrum and has a median value of about 0.05. 61 references

  6. Plasmons with orbital angular momentum

    International Nuclear Information System (INIS)

    Mendonca, J. T.; Ali, S.; Thide, B.

    2009-01-01

    Electron plasma waves carrying orbital angular momentum are investigated in an unmagnetized collisionless plasma composed of inertial electrons and static ions. For this purpose, the usual plasmon dispersion relation is employed to derive an approximate paraxial equation. The latter is analyzed with a Gaussian beam solution. For a finite angular momentum associated with the plasmon, Laguerre-Gaussian (LG) solutions are employed for solving the electrostatic potential problem which gives approximate solution and is valid for plasmon beams in the paraxial approximation. The LG potential determines the electric field components and energy flux of plasmons with finite angular momentum. Numerical illustrations show that the radial and angular mode numbers strongly modify the profiles of the LG potential.

  7. The X-ray Astronomy Recovery Mission

    Science.gov (United States)

    Tashiro, M.; Kelley, R.

    2017-10-01

    On 25 March 2016, the Japanese 6th X-ray astronomical satellite ASTRO-H (Hitomi), launched on February 17, lost communication after a series of mishap in its attitude control system. In response to the mishap the X-ray astronomy community and JAXA analyzed the direct and root cause of the mishap and investigated possibility of a recovery mission with the international collaborator NASA and ESA. Thanks to great effort of scientists, agencies, and governments, the X-ray Astronomy Recovery Mission (XARM) are proposed. The recovery mission is planned to resume high resolution X-ray spectroscopy with imaging realized by Hitomi under the international collaboration in the shortest time possible, simply by focusing one of the main science goals of Hitomi Resolving astrophysical problems by precise high-resolution X-ray spectroscopy'. XARM will carry a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly, and an aligned X-ray CCD camera covering the same energy band and wider field of view, but no hard X-ray or soft gamma-ray instruments are onboard. In this paper, we introduce the science objectives, mission concept, and schedule of XARM.

  8. High Energy Astronomy Observatory (HEAO) Illustration

    Science.gov (United States)

    1975-01-01

    The family of High Energy Astronomy Observatory (HEAO) instruments consisted of three unmarned scientific observatories capable of detecting the x-rays emitted by the celestial bodies with high sensitivity and high resolution. The celestial gamma-ray and cosmic-ray fluxes were also collected and studied to learn more about the mysteries of the universe. High-Energy rays cannot be studied by Earth-based observatories because of the obscuring effects of the atmosphere that prevent the rays from reaching the Earth's surface. They had been observed initially by sounding rockets and balloons, and by small satellites that do not possess the needed instrumentation capabilities required for high data resolution and sensitivity. The HEAO carried the instrumentation necessary for this capability. In this photograph, an artist's concept of three HEAO spacecraft is shown: HEAO-1, launched on August 12, 1977; HEAO-2, launched on November 13, 1978; and HEAO-3, launched on September 20. 1979.

  9. Astronomy Enrollments and Degrees: Results from the 2012 Survey of Astronomy Enrollments and Degrees. Focus On

    Science.gov (United States)

    Mulvey, Patrick; Nicholson, Starr

    2014-01-01

    Interest in astronomy degrees in the U.S. remains strong, with astronomy enrollments at or near all-time highs for the 2012-13 academic year. The total number of students taking an introductory astronomy course at a degree-granting physics or astronomy department is approaching 200,000. Enrollments in introductory astronomy courses have been…

  10. Astronomy for beginners

    CERN Document Server

    Becan, Jeff

    2008-01-01

    Astronomy For Beginners is a friendly and accessible guide to our universe, our galaxy, our solar system and the planet we call home. Each year as we cruise through space on this tiny blue-green wonder, a number of amazing and remarkable events occur. For example, like clockwork, we'll run head-on into asteroid and cometary debris that spreads shooting stars across our skies. On occasion, we'll get to watch the disk of the Moon passing the Sun, casting its shadow on the face of the Earth, and sometimes we'll get to watch our own shadow as it glides across the face of the Moon. The Sun's path w

  11. Gravitational wave astronomy

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    In the past year, the LIGO-Virgo Collaboration announced the first secure detection of gravitational waves. This discovery heralds the beginning of gravitational wave astronomy: the use of gravitational waves as a tool for studying the dense and dynamical universe. In this talk, I will describe the full spectrum of gravitational waves, from Hubble-scale modes, through waves with periods of years, hours and milliseconds. I will describe the different techniques one uses to measure the waves in these bands, current and planned facilities for implementing these techniques, and the broad range of sources which produce the radiation. I will discuss what we might expect to learn as more events and sources are measured, and as this field matures into a standard part of the astronomical milieu.

  12. Astronomy of Nabta Playa

    Science.gov (United States)

    McK Mahille, J.; Schild, R.; Wendorf, F.; Brenmer, R.

    2007-07-01

    The repetitive orientation of megaliths, human burials, and cattle burials toward the northern regions of the sky reveals a very early symbolic connection to the heavens at Nabta Playa, Egypt. The groups of shaped stones facing north may have represented spirits of individuals who died on the trail or locally. A second piece of evidence for astronomy at Nabta Playa is the stone circle with its two sightlines toward the north and toward the rising sun at the June solstice. Finally, the five alignments of megaliths, which were oriented to bright stars in the fifth millennium, suggest an even more careful attention to the heavens. The "empty tombs" and deeply buried table rocks of the Complex Structures provide some of the greatest enigmas of Nabta Playa. The recurrent symbolism of the ceremonial centre involves issues that would have been of both practical and symbolic importance to the nomads: death, water, cattle, sun, and stars.

  13. Astronomy a visual guide

    CERN Document Server

    Garlick, Mark A

    2004-01-01

    Space has fascinated man and challenged scientists for centuries and astronomy is the oldest and one of the most dynamic of the sciences. Here is a book that will stimulate your curiosity and feed your imagination. Detailed and fascinating text is clearly and richly illustrated with fabulous, vibrant photographs and diagrams. This is a comprehensive guide to understanding and observing the night sky, from distant stars and galaxies to our neighbouring planets; from comets to shooting stars; from eclipses to black holes. With details of the latest space probes, a series of monthly sky maps to provide guidance for the amateur observer and the latest photos from space, this book brings the beauty and wonder of our universe into your living room and will have you reaching for the telescope!

  14. Astronomy and political theory

    Science.gov (United States)

    Campion, Nicholas

    2011-06-01

    This paper will argue that astronomical models have long been applied to political theory, from the use of the Sun as a symbol of the emperor in Rome to the application of Copernican theory to the needs of absolute monarchy. We will begin with consideration of astral divination (the use of astronomy to ascertain divine intentions) in the ancient Near East. Particular attention will be paid to the use of Newton's discovery that the universe operates according to a single set of laws in order to support concepts of political quality and eighteenth century Natural Rights theory. We will conclude with consideration of arguments that the discovery of the expanding, multi-galaxy universe, stimulated political uncertainty in the 1930s, and that photographs of the Earth from Apollo spacecraft encouraged concepts of the `global village'.

  15. Interdisciplinary Astronomy Activities

    Science.gov (United States)

    Nerantzis, Nikolaos; Mitrouda, Aikaterini; Reizopoulou, Ioanna; Sidiropoulou, Eirini; Hatzidimitriou, Antonios

    2016-04-01

    On November 9th, 2015, three didactical hours were dedicated to Interdisciplinary Astronomy Activities (http://wp.me/p6Hte2-1I). Our students and their teachers formed three groups and in rotation, were engaged with the following activities: (a) viewing unique images of the Cosmos in the mobile planetarium STARLAB (http://www.planitario.gr/tholos-starlab-classic-standard.html), (b) watching the following videos: Journey to the end of the universe (https://youtu.be/Ufl_Nwbl8xs), Rosetta update (https://youtu.be/nQ9ivd7wv30), The Solar System (https://youtu.be/d66dsagrTa0), Ambition the film (https://youtu.be/H08tGjXNHO4) in the school's library. Students and teachers were informed about our solar system, the Rosetta mission, the universe, etc. and (c) tactile activities such as Meet our home and Meet our neighbors (http://astroedu.iau.org, http://nuclio.org/astroneighbours/resources) and the creation of planets' 3D models (Geology-Geography A' Class Student's book, pg.15). With the activities above we had the pleasure to join the Cosmic Light Edu Kit / International Year of Light 2015 program. After our Interdisciplinary Astronomy Activities, we did a "small" research: our students had to fill an evaluation about their educational gains and the results can be found here http://wp.me/p6Hte2-2q. Moreover, we discussed about Big Ideas of Science (http://wp.me/p3oRiZ-dm) and through the "big" impact of the Rosetta mission & the infinity of our universe, we print posters with relevant topics and place them to the classrooms. We thank Rosa Doran (Nuclio - President of the Executive Council) for her continuous assistance and support on innovative science teaching proposals. She is an inspiration.

  16. Astronomy in laboratory

    Science.gov (United States)

    Suzuki, B.

    2006-08-01

    It is not easy to practice astronomical observation in a high school. It is difficult to teach authentic astronomy because real-world conditions cannot be reproduced in the classroom. However, the following ideas produce some interesting experiments. 1. The reappearance experiment of the meteor spectrum. We produced emission spectra by using a gas burner and welding. It can be understood that the luminosity of emission lines varies according to temperature. Furthermore, we mixed in liquid chlorides of Na, Ca, Fe, Sg, Si, etc., in different proportions tomimic different meteor spectra. We then observed the time changes of the luminosity using a video camcorder that we attached to a spectroscope. The spectrum in the experiment closely resembled that of a meteor. 2. The verification of the black-drop phenomenon.Long ago, the black-drop phenomenon became important in the case of Venus's passage between the Earth and the Sun, a transit of Venus. We tried to reproduce this phenomenon by using a small ball painted black, solar light, and an artificial illuminant. The profile of the reproduced image was then checked in detail. We found that this phenomenon depended on the influence of the limb darkening of the Sun, the scintillation of the Earth's atmosphere, and the optical performance of the telescope. Furthermore, we imitated Venus's atmosphere as an additional experiment by applying oil on the surface of the small ball. It resulted in an interesting profile but was not a sufficient experiment. Of course, these experiments are in conditions that are very different from the actual physical conditions. However, we think that they provide a very effective method for enhancing students' interest in astronomy. We are planning other experiments with similar themes.

  17. Applied Historical Astronomy

    Science.gov (United States)

    Stephenson, F. Richard

    2014-01-01

    F. Richard Stephenson has spent most of his research career -- spanning more than 45 years -- studying various aspects of Applied Historical Astronomy. The aim of this interdisciplinary subject is the application of historical astronomical records to the investigation of problems in modern astronomy and geophysics. Stephenson has almost exclusively concentrated on pre-telescopic records, especially those preserved from ancient and medieval times -- the earliest reliable observations dating from around 700 BC. The records which have mainly interested him are of eclipses (both solar and lunar), supernovae, sunspots and aurorae, and Halley's Comet. The main sources of early astronomical data are fourfold: records from ancient and medieval East Asia (China, together with Korea and Japan); ancient Babylon; ancient and medieval Europe; and the medieval Arab world. A feature of Stephenson's research is the direct consultation of early astronomical texts in their original language -- either working unaided or with the help of colleagues. He has also developed a variety of techniques to help interpret the various observations. Most pre-telescopic observations are very crude by present-day standards. In addition, early motives for skywatching were more often astrological rather than scientific. Despite these drawbacks, ancient and medieval astronomical records have two remarkable advantages over modern data. Firstly, they can enable the investigation of long-term trends (e.g. in the terrestrial rate of rotation), which in the relatively short period covered by telescopic observations are obscured by short-term fluctuations. Secondly, over the lengthy time-scale which they cover, significant numbers of very rare events (such as Galactic supernovae) were reported, which have few -- if any-- counterparts in the telescopic record. In his various researches, Stephenson has mainly focused his attention on two specific topics. These are: (i) long-term changes in the Earth's rate of

  18. Alaska Athabascan stellar astronomy

    Science.gov (United States)

    Cannon, Christopher M.

    2014-01-01

    Stellar astronomy is a fundamental component of Alaska Athabascan cultures that facilitates time-reckoning, navigation, weather forecasting, and cosmology. Evidence from the linguistic record suggests that a group of stars corresponding to the Big Dipper is the only widely attested constellation across the Northern Athabascan languages. However, instruction from expert Athabascan consultants shows that the correlation of these names with the Big Dipper is only partial. In Alaska Gwich'in, Ahtna, and Upper Tanana languages the Big Dipper is identified as one part of a much larger circumpolar humanoid constellation that spans more than 133 degrees across the sky. The Big Dipper is identified as a tail, while the other remaining asterisms within the humanoid constellation are named using other body part terms. The concept of a whole-sky humanoid constellation provides a single unifying system for mapping the night sky, and the reliance on body-part metaphors renders the system highly mnemonic. By recognizing one part of the constellation the stargazer is immediately able to identify the remaining parts based on an existing mental map of the human body. The circumpolar position of a whole-sky constellation yields a highly functional system that facilitates both navigation and time-reckoning in the subarctic. Northern Athabascan astronomy is not only much richer than previously described; it also provides evidence for a completely novel and previously undocumented way of conceptualizing the sky---one that is unique to the subarctic and uniquely adapted to northern cultures. The concept of a large humanoid constellation may be widespread across the entire subarctic and have great antiquity. In addition, the use of cognate body part terms describing asterisms within humanoid constellations is similarly found in Navajo, suggesting a common ancestor from which Northern and Southern Athabascan stellar naming strategies derived.

  19. Misconceptions in Astronomy: Before and After a Constructivist Learning Environment

    Science.gov (United States)

    Ruzhitskaya, Lanika; Speck, A.

    2009-01-01

    We present results of a pilot study on college students’ misconceptions in astronomy. The study was conducted on the campus of a Midwestern university among 43 non-science major students enrolled in an introductory astronomy laboratory course. The laboratory course was based on a constructivist learning environment where students learned astronomy by doing astronomy. During the course, students worked with educational simulations created by Project CLEA team and RedShift College Education Astronomy Workbook by Bill Walker as well as were involved in think-pair-share discussions based on Lecture-Tutorials (Prather et al 2008). Several laboratories were prompted by an instructor's brief presentations. On the first and last days of the course students were surveyed on what their beliefs were about causes of the seasons, the moon's apparent size in the sky and its phases, planetary orbits, structure of the solar system, the sun, distant stars, and the nature of light. The majority of the surveys’ questions were based on Neil Comins’ 50 most commonly cited misconceptions. The outcome of the study showed that while students constructed correct understanding of a number of phenomena, they also created a set of new misconceptions. For example, if on the first day of the course, nine out of 43 students knew what caused the seasons on Earth; on the last day of the course, 20 students gained the similar understanding. However, by the end of the course more students believed that smaller planets must rotate faster based on the conservation of angular momentum and Kepler's laws. Our findings suggest that misconceptions pointed out by Neil Comins over a decade ago are still relevant today; and that learning based exclusively on simulations and collaborative group discussions does not necessarily produce the best results, but may set a ground for creating new misconceptions.

  20. Astronomy at the frontiers of science

    CERN Document Server

    2011-01-01

    Astronomy is by nature an interdisciplinary activity: it involves mathematics, physics, chemistry and biology. Astronomers use (and often develop) the latest technology, the fastest computers and the most refined software.  In this book twenty-two leading scientists from nine countries talk about how astronomy interacts with these other sciences. They describe modern instruments used in astronomy and the relations between astronomy and technology, industry, politics and philosophy. They also discuss what it means to be an astronomer, the history of astronomy, and the place of astronomy in society today.   The book contains twenty chapters grouped in four parts: ASTRONOMY AND PHYSICS discusses the place of astronomy among various branches of (mostly high-energy) physics. ASTRONOMY IN SOCIETY describes not only the historical context of astronomy, but issues facing astronomers today, including funding, planning, worldwide collaboration and links with industry. THE TOOLS OF OBSERVATION AND THE PROFESSION OF AS...

  1. Uncertainty principle for angular position and angular momentum

    International Nuclear Information System (INIS)

    Franke-Arnold, Sonja; Barnett, Stephen M; Yao, Eric; Leach, Jonathan; Courtial, Johannes; Padgett, Miles

    2004-01-01

    The uncertainty principle places fundamental limits on the accuracy with which we are able to measure the values of different physical quantities (Heisenberg 1949 The Physical Principles of the Quantum Theory (New York: Dover); Robertson 1929 Phys. Rev. 34 127). This has profound effects not only on the microscopic but also on the macroscopic level of physical systems. The most familiar form of the uncertainty principle relates the uncertainties in position and linear momentum. Other manifestations include those relating uncertainty in energy to uncertainty in time duration, phase of an electromagnetic field to photon number and angular position to angular momentum (Vaccaro and Pegg 1990 J. Mod. Opt. 37 17; Barnett and Pegg 1990 Phys. Rev. A 41 3427). In this paper, we report the first observation of the last of these uncertainty relations and derive the associated states that satisfy the equality in the uncertainty relation. We confirm the form of these states by detailed measurement of the angular momentum of a light beam after passage through an appropriate angular aperture. The angular uncertainty principle applies to all physical systems and is particularly important for systems with cylindrical symmetry

  2. A Grand Vision for European Astronomy

    Science.gov (United States)

    2007-09-01

    Today, and for the first time, astronomers share their global Science Vision for European Astronomy in the next two decades. This two-year long effort by the ASTRONET network of funding agencies, sponsored by the European Commission and coordinated by INSU-CNRS, underscores Europe's ascension to world leadership in astronomy and its will to maintain that position. It will be followed in just over a year by a prioritised roadmap for the observational facilities needed to implement the Vision. Implementation of these plans will ensure that Europe fully contributes to Mankind's ever deeper understanding of the wonders of our Universe. astronet logo "This is a great opportunity to help create a vibrant long-term future for astronomy and science" says Tim de Zeeuw (Leiden Observatory, The Netherlands) who led this community-wide effort. The ASTRONET Science Vision provides a comprehensive overview of the most important scientific questions that European astronomy should address in the next twenty years. The four key questions are the extremes of the Universe, from the nature of the dark matter and dark energy that comprise over 95% of the Universe to the physics of extreme objects such as black holes, neutron stars, and gamma-ray bursts; the formation of galaxies from the first seeds to our Milky Way; the formation of stars and planets and the origin of life; and the crucial question of how do we (and our Solar System) fit in the global picture. These themes reach well beyond the realm of traditional astronomy into the frontiers of physics and biology. The Vision identifies the major new facilities that will be needed to achieve these goals, but also stresses the need for parallel developments in theory and numerical simulations, high-performance computing resources, efficient astronomical data archiving and the European Virtual Observatory, as well as in laboratory astrophysics. "This report is a key input for the even more challenging task of developing a prioritised

  3. Demographics in Astronomy and Astrophysics

    Science.gov (United States)

    Ulvestad, James S.

    2011-05-01

    Astronomy has been undergoing a significant demographic shift over the last several decades, as shown by data presented in the 2000 National Research Council (NRC) report "Federal Funding of Astronomical Research," and the 2010 NRC report, "New Worlds, New Horizons in Astronomy and Astrophysics." For example, the number of advertised postdoctoral positions in astronomy has increased much more rapldly than the number of faculty positions, contributing to a holding pattern of early-career astronomers in multiple postdoctoral positions. This talk will summarize some of the current demographic trends in astronomy, including information about gender and ethnic diversity, and describe some of the possible implications for the future. I thank the members of the Astro2010 Demographics Study Group, as well as numerous white-paper contributors to Astro2010, for providing data and analyses.

  4. Lunar based gamma ray astronomy

    International Nuclear Information System (INIS)

    Haymes, R.C.

    1985-01-01

    Gamma ray astronomy represents the study of the universe on the basis of the electromagnetic radiation with the highest energy. Gamma ray astronomy provides a crucial tool for the understanding of astronomical phenomena, taking into account nucleosynthesis in supernovae, black holes, active galaxies, quasars, the sources of cosmic rays, neutron stars, and matter-antimatter annihilation. Difficulties concerning the conduction of studies by gamma ray astronomy are related to the necessity to perform such studies far from earth because the atmosphere is a source of gamma rays. Studies involving the use of gamma ray instruments in earth orbit have been conducted, and more gamma ray astronomy observations are planned for the future. Imperfections of studies conducted in low earth orbit could be overcome by estalishing an observatory on the moon which represents a satellite orbiting at 60 earth radii. Details concerning such an observatory are discussed. 5 references

  5. History of the modern astronomy

    International Nuclear Information System (INIS)

    Herrmann, D.B.

    1984-01-01

    The book treats the following topics: structure and motion of the sky - classical astronomy, origin of astrophysics, macrocosm - microcosm, and techniques and organization of research. 86 black-and-white and 15 color plates are included

  6. The physics-astronomy frontier

    International Nuclear Information System (INIS)

    Hoyle, F.; Narlikar, K.

    1980-01-01

    Spacetime diagrams and the structure of matter are considered, and aspects of electrical interaction are investigated. Attention is given to radiation, quantum mechanics, spectrum lines, black bodies, stellar spectra, the H-R diagram, radio astronomy, millimeter-wave astronomy, interstellar grains and infrared astronomy, and X-ray astronomy. The strong and weak interactions are examined, taking into account atoms, nuclei, the evolution of stars, and the measurement of astronomical distances. A description of gravitational interaction is also presented. The laws of motion and gravitation are considered along with black holes, the significance of cosmology, Hubble's law, the expanding universe, the symmetries of the universe, Olbers' paradox, the big-bang universe, Mach's principle, the meaning of the expansion of the system of galaxies, the redshift-magnitude relation of Hubble and Humason, the early universe, and the geometry of special relativity

  7. Astronomy Week in Madeira, Portugal

    Science.gov (United States)

    Augusto, P.; Sobrinho, J. L.

    2012-05-01

    The outreach programme Semanas da Astronomia (Astronomy Weeks) is held in late spring or summer on the island of Madeira, Portugal. This programme has been attracting enough interest to be mentioned in the regional press/TV/radio every year and is now, without doubt, the astronomical highlight of the year on Madeira. We believe that this programme is a good case study for showing how to attract the general public to astronomy in a small (population 250 000, area 900 km2) and fairly isolated place such as Madeira. Our Astronomy Weeks have been different each year and have so far included exhibitions, courses, talks, a forum, documentaries, observing sessions (some with blackouts), music and an astro party. These efforts may contribute towards putting Madeira on the map with respect to observational astronomy, and have also contributed to the planned installation of two observatories in the island.

  8. From astronomy to data science

    Science.gov (United States)

    Rodriguez Zaurín, Javier

    2018-01-01

    After almost ten years in academia I took one of the best decisions of my life: to leave it. This is my experience transitioning from astronomy to data science in search of a more open, fast-paced working environment.

  9. Essays on medieval computational astronomy

    CERN Document Server

    Bergón, José Chabás

    2014-01-01

    In Essays on Medieval Computational Astronomy the authors provide examples of original and intelligent approaches and solutions given by medieval astronomers to the problems of their discipline, mostly presented in the form of astronomical tables.

  10. Indigenous Astronomy in Southern Africa

    Science.gov (United States)

    Medupe, Thebe Rodney

    The cultural Astronomy of Southern African peoples has been a subject of many studies spanning atleast over a century. Some of the studies were biased against the notion that Southern African could have any interest in studying the natural environment to benefit their societies. In this chapter, I summarize the current knowledge about cultural Astronomy of Southern African peoples and highlight points of further research.

  11. Radio astronomy on the moon

    International Nuclear Information System (INIS)

    Burns, J.O.; Asbell, J.

    1987-01-01

    The advantages and opportunities for radio astronomy on the moon during the early to mid 21st century are reviewed. In particular, it is argued that the lack of atmosphere, the extremely low seismic activity, the low RF background, and the natural cryogenic environment make the moon (particularly the far side and the poles) a nearly ideal locale for submillimeter/FIR to VLF (below 10 MHz) radio astronomy. 22 references

  12. Astronomy at the Market

    Science.gov (United States)

    Roten, Robert; Constantin, A.; Christensen, E.; Dick, E.; Lapolla, J.; Nutter, A.; Corcoran, J.; DiDomenico, N.; Eskridge, B.; Saikin, A.

    2014-01-01

    We present here an energetic grass-roots outreach program run entirely by undergraduate physics and astronomy majors at James Madison University. Our "Team Awestronomy" takes Astronomy out to the Market, literally. Once a month, for eight months during the academic year, the group sets up a “scientific corner” at the Harrisonburg Farmers Market, offering people the chance to meet with astrophysicists (in the making) and discuss science. Our group members wear t-shirts with simple messages like “Ask me about the Sun,” “...about Black Holes and Mega-Masers” or “...about Big Bang” that initiate the dialog. We help our audience with observations of solar activity through our department’s Coronado telescope equipped with a safe H-alpha filter, sunspotters, and the incredibly simple yet durable and accurate handheld (Project Star) spectrometers, and invite them to the free Saturday Planetarium shows and the star parties hosted by our department on the JMU campus. The team is also prepared with a suite of fun activities aimed particularly at K-5 kids, e.g., building (and eating, after investigating out-gassing properties of) ”dirty comets,” making craters (in pans with flour or sand) and testing how different types of impactors (pebbles, ping-pong balls or even crumpled aluminum foil) affect crater formation, and demonstrations of shock wave created in supernova explosions. The main goals of this outreach program are: 1) to illustrate to people of all ages that science is a fun, creative, and exciting process; 2) to empower people to be curious and to ask questions; 3) to demonstrate that science is a viable career path chosen by many diverse individuals; and 4) to nurture a sense of wonder and awe for the Universe. While this outreach program is aimed at a very general audience, of an extremely wide range, we expect to produce a significant impact on K-12 students in general and in particular on the home-schooled kids. There is a relatively high

  13. Instant AngularJS starter

    CERN Document Server

    Menard, Dan

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. This book is written in an easytoread style, with a strong emphasis on realworld, practical examples. Stepbystep explanations are provided for performing important tasks.This book is for web developers familiar with JavascriptIt doesn't cover the history of AngularJS, and it's not a pitch to convince you that AngularJS is the best framework on the entire web. It's a guide to help you learn everything you need to know about AngularJS in as few pa

  14. Astronomy in India a historical perspective

    CERN Document Server

    2014-01-01

    India has a strong and ancient tradition of astronomy, which seamlessly merges with the current activities in Astronomy and Astrophysics in the country. While the younger generation of astronomers and students are reasonably familiar with the current facilities and the astronomical research, they might not have an equally good knowledge of the rich history of Indian astronomy. This particular volume, brought out as a part of the Platinum Jubilee Celebrations of Indian National Science Academy, concentrates on selected aspects of historical development of Indian astronomy in the form of six invited chapters. Two of the chapters – by Balachandra Rao and M.S. Sriram – cover ancient astronomy and the development of calculus in the ancient Kerela text Yuktibhasa. The other four chapters by B.V. Sreekantan, Siraj Hasan, Govind Swarup and Jayant Narlikar deal with the contemporary history of Indian astronomy covering space astronomy, optical astronomy, radio astronomy and developments in relativistic astrophysic...

  15. Astronomy and Atmospheric Optics

    Science.gov (United States)

    Cowley, Les; Gaina, Alex

    2011-12-01

    The authors discusse the insuccess of the observation of the Total Eclipse of the Moon from 10 december 2011 in Romania and relate them with meteoconditions. Only a very short part of the last penumbral phase was observed, while the inital part and the totality was not observed due to very dense clouds. The change in color and brightness during this phase was signaled. Meanwhile, there is an area of science where clouds are of great use and interest. This area is Atmospheric optics, while the science which study clouds is meteorology. Clouds in combination with Solar and Moon light could give rise to a variety of strange, rare and unobvious phenomena in the atmosphere (sky), sometimes confused with Unidentified Flying Objects (UFO). The importance of meteorology for astronomy and atmospheric optics is underlined and an invitation to astronomers to use unfavourable days for athmospheric observations was sent. The web address of the site by Les Cowley, designed for atmospheric optics phenomena is contained in the text of the entry.

  16. Edible Astronomy Demonstrations

    Science.gov (United States)

    Lubowich, Donald A.

    2007-12-01

    Astronomy demonstrations with edible ingredients are an effective way to increase student interest and knowledge of astronomical concepts. This approach has been successful with all age groups from elementary school through college students - and the students remember these demonstrations after they are presented. In this poster I describe edible demonstrations I have created to simulate the expansion of the universe (using big-bang chocolate chip cookies); differentiation during the formation of the Earth and planets (using chocolate or chocolate milk with marshmallows, cereal, candy pieces or nuts); and radioactivity/radioactive dating (using popcorn). Other possible demonstrations include: plate tectonics (crackers with peanut butter and jelly); convection (miso soup or hot chocolate); mud flows on Mars (melted chocolate poured over angel food cake); formation of the Galactic disk (pizza); formation of spiral arms (coffee with cream); the curvature of Space (Pringles); constellations patterns with chocolate chips and chocolate chip cookies; planet shaped cookies; star shaped cookies with different colored frostings; coffee or chocolate milk measurement of solar radiation; Oreo cookie lunar phases. Sometimes the students eat the results of the astronomical demonstrations. These demonstrations are an effective teaching tool and can be adapted for cultural, culinary, and ethnic differences among the students.

  17. Gnuastro: GNU Astronomy Utilities

    Science.gov (United States)

    Akhlaghi, Mohammad

    2018-01-01

    Gnuastro (GNU Astronomy Utilities) manipulates and analyzes astronomical data. It is an official GNU package of a large collection of programs and C/C++ library functions. Command-line programs perform arithmetic operations on images, convert FITS images to common types like JPG or PDF, convolve an image with a given kernel or matching of kernels, perform cosmological calculations, crop parts of large images (possibly in multiple files), manipulate FITS extensions and keywords, and perform statistical operations. In addition, it contains programs to make catalogs from detection maps, add noise, make mock profiles with a variety of radial functions using monte-carlo integration for their centers, match catalogs, and detect objects in an image among many other operations. The command-line programs share the same basic command-line user interface for the comfort of both the users and developers. Gnuastro is written to comply fully with the GNU coding standards and integrates well with all Unix-like operating systems. This enables astronomers to expect a fully familiar experience in the source code, building, installing and command-line user interaction that they have seen in all the other GNU software that they use. Gnuastro's extensive library is included for users who want to build their own unique programs.

  18. Astronomy Research Seminar

    Science.gov (United States)

    Johson, Jolyon; Genet, Russell; Armstrong, James; Boyce, Grady; Boyce, Pat; Brewer, Mark; Buchheim, Robert; Carro, Joseph; Estrada, Reed; Estrada, Chris; Freed, Rachel; Gillette, Sean; Harshaw, Richard; Hollis, Thomas; Kenney, John; McGaughey, Seven; McNab, Christine; Mohanan, Kakkala; Sepulveda, Babs; Wallace, Dan; Wallen, Vera

    2015-05-01

    Traditional science lectures and labs are often enhanced through project- and team-based learning. Some students go beyond these classroom studies by conducting research, often under the guidance of university professors. A one-semester astronomy research seminar was initiated in 2006 in collaboration with the community of professional and amateur double star astronomers. The result was dozens of jointly-authored papers published in the Journal of Double Star Observations and the Annual Proceedings of the Society of Astronomical Sciences. This seminar, and its affiliated community, launched a series of conferences and books, providing students with additional forums to share their double star research. The original seminar, and its derivatives, enhanced educational careers through college admissions and scholarships. To expand the seminar's reach, it was restructured from a few teams at one school, to many teams, each from a different school. A volunteer from each school became an assistant instructor. Most of them were seminar veterans, experienced astronomers, or science teachers. The assistant instructors, in turn, recruited enthusiastic students for their teams. To avoid student and instructor overload, the seminar focused on its three deliverables: a formal proposal, published paper, and public PowerPoint presentation. Future seminars may offer other astronomical research options such as exoplanet transit or eclipsing binary photometry.

  19. Grab 'n' go astronomy

    CERN Document Server

    English, Neil

    2014-01-01

      Like everyone else, most amateur astronomers live busy lives. After a long day, the last thing you want as an observer is to have to lug out a large telescope and spend an hour getting it ready before it can be used. Maybe you are going somewhere sure to have dark skies, but you don’t necessarily want astronomy to dominate the trip. Or you are not quite committed to owning a large telescope, but curious enough to see what a smaller, portable setup can accomplish. These are times when a small “grab ’n’ go” telescope, or even a pair of binoculars, is the ideal in­strument. And this book can guide you in choosing and best utilizing that equipment.   What makes a telescope fall into the “grab ’n’ go” category? That’s easy – speed of setting up, ease of use, and above all, portability. This ambitious text is dedicated to those who love to or – because of their limited time – must observe the sky at a moment’s notice. Whether observing from the comfort of a backyard or while on busi...

  20. Automated Angular Momentum Recoupling Algebra

    Science.gov (United States)

    Williams, H. T.; Silbar, Richard R.

    1992-04-01

    We present a set of heuristic rules for algebraic solution of angular momentum recoupling problems. The general problem reduces to that of finding an optimal path from one binary tree (representing the angular momentum coupling scheme for the reduced matrix element) to another (representing the sub-integrals and spin sums to be done). The method lends itself to implementation on a microcomputer, and we have developed such an implementation using a dialect of LISP. We describe both how our code, called RACAH, works and how it appears to the user. We illustrate the use of RACAH for several transition and scattering amplitude matrix elements occurring in atomic, nuclear, and particle physics.

  1. Research amateur astronomy; Proceedings of the Symposium, La Paz, Mexico, July 7-12, 1991

    Science.gov (United States)

    Edberg, Stephen J.

    The present volume on amateur astronomy deals with solar observations; planet, asteroid, and comet studies; photometry; education and communication; and history and sociology. Particular attention is given to the observation of the 1984 annular eclipse in Mexico, amateur solar astronomy in Germany, the Ashen Light of Venus, dust clouds on Mars in 1990, and the importance of comets Encke and Machholz. Also discussed are a UBVRI and occultation photometry acquisition and reduction software package for PC-based observatories, a Skyweek weekly newsletter on astronomy and spaceflight, and the Hubble Space Telescope and the Goddard High Resolution Spectrograph.

  2. Research amateur astronomy; Proceedings of the Symposium, La Paz, Mexico, July 7-12, 1991

    Science.gov (United States)

    Edberg, Stephen J. (Editor)

    1992-01-01

    The present volume on amateur astronomy deals with solar observations; planet, asteroid, and comet studies; photometry; education and communication; and history and sociology. Particular attention is given to the observation of the 1984 annular eclipse in Mexico, amateur solar astronomy in Germany, the Ashen Light of Venus, dust clouds on Mars in 1990, and the importance of comets Encke and Machholz. Also discussed are a UBVRI and occultation photometry acquisition and reduction software package for PC-based observatories, a Skyweek weekly newsletter on astronomy and spaceflight, and the Hubble Space Telescope and the Goddard High Resolution Spectrograph.

  3. Characteristic evolutions in numerical relativity using six angular patches

    International Nuclear Information System (INIS)

    Reisswig, Christian; Bishop, Nigel T; Lai, Chi Wai; Thornburg, Jonathan; Szilagyi, Bela

    2007-01-01

    The characteristic approach to numerical relativity is a useful tool in evolving gravitational systems. In the past this has been implemented using two patches of stereographic angular coordinates. In other applications, a six-patch angular coordinate system has proved effective. Here we investigate the use of a six-patch system in characteristic numerical relativity, by comparing an existing two-patch implementation (using second-order finite differencing throughout) with a new six-patch implementation (using either second- or fourth-order finite differencing for the angular derivatives). We compare these different codes by monitoring the Einstein constraint equations, numerically evaluated independently from the evolution. We find that, compared to the (second-order) two-patch code at equivalent resolutions, the errors of the second-order six-patch code are smaller by a factor of about 2, and the errors of the fourth-order six-patch code are smaller by a factor of nearly 50

  4. Analysis of angular reading distortions of photographic images.

    Science.gov (United States)

    Codarin, Gabriela F; Felicio, Lilian R; Coelho, Daniel M; Oliveira, Anamaria S

    2012-01-01

    Although photogrammetry is a widespread technique in the health field, despite of the methodological efforts distortions in the angular readings of the images are common. To measure the error of angular measurements in photo images with different digital resolutions in an object with pre-determined angles. We used a rubber ball with 52 cm in circumference. The object was previously marked with angles of 10°, 30°, 60° and 90° degrees. The photographic records were performed with the focal axis of the camera perpendicular and three meters away from the object, without the use of optical zoom and a resolution of 3, 5 and 10 Megapixels (Mp). All photographic records were stored and a previously trained experimenter using the computer program ImageJ analyzed the angular values of each photo. The measurements were performed twice within a fifteen-days interval. Subsequently, we calculated the accuracy, relative error and error in degrees values, precision and the Intraclass Correlation Coefficient (ICC). When analyzing the angle of 10°, the average accuracy of measurements was higher for those records of 3 Mp resolution compared to 5 and 10 Mp resolutions. The ICC was considered excellent for all resolutions. With regards to the analyzed angles in photographic records, it was possible to verify that the 90-degree angle photographs were more accurate, had lower relative error and error in degrees, and were more precise, regardless of image resolution. The photographs records that were taken with a 3 Mp resolution provided great accuracy and precision measurements and lower errors values, suggesting to be the proper resolution to generate image of angles of 10º and 30º.

  5. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... High angular resolution spectroscopy obtained with the Hubble Space Telescope (HST) has revealed a remarkable population of galaxies hosting dwarf Seyfert nuclei with an unusually large broad-line region (BLR). These objects are remarkable for two reasons. Firstly, the size of the BLR can, in some ...

  6. Synthetic aperture imaging in astronomy and aerospace: introduction.

    Science.gov (United States)

    Creech-Eakman, Michelle J; Carney, P Scott; Buscher, David F; Shao, Michael

    2017-05-01

    Aperture synthesis methods allow the reconstruction of images with the angular resolutions exceeding that of extremely large monolithic apertures by using arrays of smaller apertures together in combination. In this issue we present several papers with techniques relevant to amplitude interferometry, laser radar, and intensity interferometry applications.

  7. The Angular Momentum of Baryons and Dark Matter Halos Revisited

    Science.gov (United States)

    Kimm, Taysun; Devriendt, Julien; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A.; Dubois, Yohan

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive-mesh refinement (AMR), we find that at the time of accretion, gas and dark matter do carry a similar amount of specific angular momentum, but that it is systematically higher than that of the dark matter halo as a whole. At high redshift, freshly accreted gas rapidly streams into the central region of the halo, directly depositing this large amount of angular momentum within a sphere of radius r = 0.1R(sub vir). In contrast, dark matter particles pass through the central region unscathed, and a fraction of them ends up populating the outer regions of the halo (r/R(sub vir) > 0.1), redistributing angular momentum in the process. As a result, large-scale motions of the cosmic web have to be considered as the origin of gas angular momentum rather than its virialised dark matter halo host. This generic result holds for halos of all masses at all redshifts, as radiative cooling ensures that a significant fraction of baryons remain trapped at the centre of the halos. Despite this injection of angular momentum enriched gas, we predict an amount for stellar discs which is in fair agreement with observations at z=0. This arises because the total specific angular momentum of the baryons (gas and stars) remains close to that of dark matter halos. Indeed, our simulations indicate that any differential loss of angular momentum amplitude between the two components is minor even though dark matter halos continuously lose between half and two-thirds of their specific angular momentum modulus as they evolve. In light of our results, a substantial revision of the standard theory of disc formation seems to be required. We propose a new scenario where gas efficiently carries the angular momentum generated

  8. Technology Needs for Gamma Ray Astronomy

    Science.gov (United States)

    Gehrels, Neil

    2011-01-01

    Gamma ray astronomy is currently in an exciting period of multiple missions and a wealth of data. Results from INTEGRAL, Fermi, AGILE, Suzaku and Swift are making large contributions to our knowledge of high energy processes in the universe. The advances are due to new detector and imaging technologies. The steps to date have been from scintillators to solid state detectors for sensors and from light buckets to coded aperture masks and pair telescopes for imagers. A key direction for the future is toward focusing telescopes pushing into the hard X-ray regime and Compton telescopes and pair telescopes with fine spatial resolution for medium and high energy gamma rays. These technologies will provide finer imaging of gamma-ray sources. Importantly, they will also enable large steps forward in sensitivity by reducing background.

  9. International Olympiad on Astronomy and Astrophysics

    Science.gov (United States)

    Soonthornthum, B.; Kunjaya, C.

    2011-01-01

    The International Olympiad on Astronomy and Astrophysics, an annual astronomy and astrophysics competition for high school students, is described. Examples of problems and solutions from the competition are also given. (Contains 3 figures.)

  10. Le Point sur... Astronomie IV

    Science.gov (United States)

    Pecker, J.-C.

    Cet ouvrage regroupe des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années.Leurs auteurs sont des spécialistes participant activement à l'accroissement des connaissances dans des domaines faisant l'objet de recherches intensives. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en français, soit en anglais et accompagnées d'une bibliographie détaillée.

  11. Le Point sur... Astronomie III

    Science.gov (United States)

    Pecker, J.-C.

    Ce fascicule contient l'ensemble des textes du débat sur la cosmologie du big-bang entre Joseph Silk, Jayant V. Narlikar, arbitrés par Jean-Claude Pecker. Il regroupe également des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en francais, soit en anglais et accompagnèes d'une bibliographie dètaillèe.

  12. CONNECTING ANGULAR MOMENTUM AND GALACTIC DYNAMICS: THE COMPLEX INTERPLAY BETWEEN SPIN, MASS, AND MORPHOLOGY

    International Nuclear Information System (INIS)

    Teklu, Adelheid F.; Remus, Rhea-Silvia; Dolag, Klaus; Beck, Alexander M.; Burkert, Andreas; Schulze, Felix; Steinborn, Lisa K.; Schmidt, Andreas S.

    2015-01-01

    The evolution and distribution of the angular momentum of dark matter (DM) halos have been discussed in several studies over the past decades. In particular, the idea arose that angular momentum conservation should allow us to infer the total angular momentum of the entire DM halo from measuring the angular momentum of the baryonic component, which is populating the center of the halo, especially for disk galaxies. To test this idea and to understand the connection between the angular momentum of the DM halo and its galaxy, we use a state-of-the-art, hydrodynamical cosmological simulation taken from the set of Magneticum Pathfinder simulations. Thanks to the inclusion of the relevant physical processes, the improved underlying numerical methods, and high spatial resolution, we successfully produce populations of spheroidal and disk galaxies self-consistently. Thus, we are able to study the dependence of galactic properties on their morphology. We find that (1) the specific angular momentum of stars in disk and spheroidal galaxies as a function of their stellar mass compares well with observational results; (2) the specific angular momentum of the stars in disk galaxies is slightly smaller compared to the specific angular momentum of the cold gas, in good agreement with observations; (3) simulations including the baryonic component show a dichotomy in the specific stellar angular momentum distribution when splitting the galaxies according to their morphological type (this dichotomy can also be seen in the spin parameter, where disk galaxies populate halos with slightly larger spin compared to spheroidal galaxies); (4) disk galaxies preferentially populate halos in which the angular momentum vector of the DM component in the central part shows a better alignment to the angular momentum vector of the entire halo; and (5) the specific angular momentum of the cold gas in disk galaxies is approximately 40% smaller than the specific angular momentum of the total DM halo

  13. Vistas in astronomy. Volume 16

    International Nuclear Information System (INIS)

    Beer, A.

    1974-01-01

    A series of papers dealing with theoretical and experimental work in solar, planetary, and stellar astronomy, including stellar spectroscopy, photometry, and radio astronomy. The topics covered include: solar flares, the historical development of solar theories, the intrinsic light variation and the reflection effect in very close eclipsing binary systems with distorted components, spectroscopic binaries, early-type stars with abnormal spectra, photometric classification of the O-B stars, the nova DQ Herculis, emission nebulas at radio wavelengths, and the planetary nebulas as radio sources. (IAA)

  14. Practical astronomy with your calculator

    CERN Document Server

    Duffett-Smith, Peter

    1989-01-01

    Practical Astronomy with your Calculator, first published in 1979, has enjoyed immense success. The author's clear and easy to follow routines enable you to solve a variety of practical and recreational problems in astronomy using a scientific calculator. Mathematical complexity is kept firmly in the background, leaving just the elements necessary for swiftly making calculations. The major topics are: time, coordinate systems, the Sun, the planetary system, binary stars, the Moon, and eclipses. In the third edition there are entirely new sections on generalised coordinate transformations, nutr

  15. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1966-01-01

    Advances in Astronomy and Astrophysics, Volume 4 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with a description of objective prism and its application in space observations. The next chapter deals with the possibilities of deriving reliable models of the figure, density distribution, and gravity field of the Moon based on data obtained through Earth-bound telescopes. These topics are followed by a discussion on the ideal partially relativistic, partially degenerate gas in an exact manner. A ch

  16. Informal Education: Slacker Astronomy Podcasts

    Science.gov (United States)

    Price, A.

    2005-12-01

    Slacker Astronomy is a weekly podcast about astronomy begun in February, 2005. Each week we cover a recent astronomical news event. We present it with humor and silliness, yet we respect the intelligence of the audience and do not ``dumb it down." Since we are professional astronomers we often cover items ignored by traditional press. We currently have around 10,000 loyal weekly listeners. All our shows are rated for content and available to the public under the Creative Commons license. Both scripts and audio are also used as source material by parents, teachers and planetarium directors.

  17. Astronomy 3.0 Style

    Science.gov (United States)

    Accomazzi, A.

    2010-10-01

    Over the next decade, we will witness the development of a new infrastructure in support of data-intensive scientific research, which includes Astronomy. This new networked environment will offer both challenges and opportunities to our community and has the potential to transform the way data are described, curated and preserved. Based on the lessons learned during the development and management of the ADS, a case is made for adopting the emerging technologies and practices of the Semantic Web to support the way Astronomy research will be conducted. Examples of how small, incremental steps can, in the aggregate, make a significant difference in the provision and repurposing of astronomical data are provided.

  18. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1963-01-01

    Advances in Astronomy and Astrophysics, Volume 2 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of six chapters and begins with a summary of observational record on twilight extensions of the Venus cusps. The next chapter deals with the common and related properties of binary stars, with emphasis on the evaluation of their cataclysmic variables. Cataclysmic variables refer to an object in one of three classes: dwarf nova, nova, or supernova. These topics are followed by discussions on the eclipse phenomena and the eclipses i

  19. Multiverso: Rock'n'Astronomy

    Science.gov (United States)

    Caballero, J. A.

    2012-05-01

    In the last few years, there have been several projects involving astronomy and classical music. But have a rock band ever appeared at a science conference or an astronomer at a rock concert? We present a project, Multiverso, in which we mix rock and astronomy, together with poetry and video art (Caballero, 2010). The project started in late 2009 and has already reached tens of thousands people in Spain through the release of an album, several concert-talks, television, radio, newspapers and the internet.

  20. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1968-01-01

    Advances in Astronomy and Astrophysics, Volume 6 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with the description of improved methods for analyzing and classifying families of periodic orbits in a conservative dynamical system with two degrees of freedom. The next chapter describes the variation of fractional luminosity of distorted components of close binary systems in the course of their revolution, or the accompanying changes in radial velocity. This topic is followed by discussions on vari

  1. Stratospheric Observatory for Infrared Astronomy (SOFIA): Infrared Sensor Development and Science Capabilities

    Science.gov (United States)

    Nelson, J.; Ruzek, M.

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a unique airborne observatory designed to operate in the lower stratosphere to altitudes as high as 45,000 feet and above 99.8 percent of Earths obscuring atmospheric water vapor. SOFIA's capabilities enable science and observations that will complement and extend past, present and future infrared (IR) telescopes in wavelength range, angular and spectral resolution, and observing flexibility. The joint U.S. and German SOFIA project to develop and operate a 2.5-meter infrared airborne telescope in a Boeing 747-SP is nearing readiness for for open door flights and demonstration of early science results. Flying in the stratosphere, SOFIA allows observations throughout the infrared and submillimeter region. The SOFIA instrument complement includes broadband imagers, moderate resolution spectrographs capable of resolving broad features due to dust and large molecules, and high resolution spectrometers suitable for kinematic studies of molecular and atomic gas lines at high resolution. First science flights will begin in early 2010. A great strength of SOFIA is the enormous breadth of its capabilities and the flexibility with which those capabilities can be modified and improved to take advantage of advances in infrared technology. This paper and presentation will highlight the following points: A 2.5-meter effective-diameter optical-quality telescope for diffraction-limited imaging beyond 25 micrometers, giving the sharpest view of the sky provided by any current or developmental IR telescope operating in the 30-60 micrometers region; Wavelength coverage from 0.3 micrometers to 1.6 mm and high resolution spectroscopy (R to 105) at wavelengths between 5 and 150 micrometers; An 8 arcmin FOV allowing use of very large detector arrays; Ready observer access to science instruments which can be serviced in flight and changed between flights; A low-risk ability to incorporate new science-enabling instrument

  2. Indian Astronomy: The Missing Link in Eurocentric History of Astronomy

    Science.gov (United States)

    Haque, Shirin; Sharma, Deva

    2016-01-01

    A comprehensive history of Astronomy should show in reasonable chronological order, the contributions from wherever they arise in the world, once they are reliably documented. However, the authors note that consistently, the extremely rich contributions from Ancient Indian scholars like Aryabatha and Bhramagupta are omitted in Eurocentric…

  3. The Explorer program for astronomy and astrophysics

    International Nuclear Information System (INIS)

    Savage, B.D.; Becklin, E.E.; Cassinelli, J.P.; Dupree, A.K.; Elliot, J.L.; Hoffmann, W.F.; Hudson, H.S.; Jura, M.; Kurfess, J.; Murray, S.S.

    1986-01-01

    This report was prepared to provide NASA with a strategy for proceeding with Explorer-class programs for research in space astronomy and astrophysics. The role of Explorers in astronomy and astrophysics and their past accomplishments are discussed, as are current and future astronomy and astrophysics Explorers. Specific cost needs for an effective Explorer program are considered

  4. Division B Commission 40: Radio Astronomy

    NARCIS (Netherlands)

    Chapman, Jessica M.; Giovaninni, Gabriele; Taylor, Russell; Carilli, Christopher; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin L.; Lazio, Joseph; Morganti, Raffaella; Nan, Rendong; Rubio, Monica; Shastri, Prjaval; Kellermann, Ken; Ekers, Ronald; Ohishi, Masatoshi

    2016-01-01

    IAU Commission 40 for Radio Astronomy (hereafter C40) brought together scientists and engineers who carry out observational and theoretical research in radio astronomy and who develop and operate the ground and space-based radio astronomy facilities and instrumentation. As of June 2015, the

  5. Blazing the Trail for Astronomy Education Research

    Science.gov (United States)

    Bailey, Janelle M.; Lombardi, Doug

    2015-01-01

    Education research has long considered student learning of topics in astronomy and the space sciences, but astronomy education research as a sub-field of discipline-based education research is relatively new. Driven by a growing interest among higher education astronomy educators in improving the general education, introductory science survey…

  6. Astronomy Education Project for Guangdong High Schools

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Guangdong province is an active area in China for astronomy education and popularization. The current status and problems of astronomy education in high schools are reviewed. To tackle these problems, an astronomy education project for high school teachers and students was initiated by Guangzhou ...

  7. On Dunkl angular momenta algebra

    Energy Technology Data Exchange (ETDEWEB)

    Feigin, Misha [School of Mathematics and Statistics, University of Glasgow,15 University Gardens, Glasgow G12 8QW (United Kingdom); Hakobyan, Tigran [Yerevan State University,1 Alex Manoogian, 0025 Yerevan (Armenia); Tomsk Polytechnic University,Lenin Ave. 30, 634050 Tomsk (Russian Federation)

    2015-11-17

    We consider the quantum angular momentum generators, deformed by means of the Dunkl operators. Together with the reflection operators they generate a subalgebra in the rational Cherednik algebra associated with a finite real reflection group. We find all the defining relations of the algebra, which appear to be quadratic, and we show that the algebra is of Poincaré-Birkhoff-Witt (PBW) type. We show that this algebra contains the angular part of the Calogero-Moser Hamiltonian and that together with constants it generates the centre of the algebra. We also consider the gl(N) version of the subalgebra of the rational Cherednik algebra and show that it is a non-homogeneous quadratic algebra of PBW type as well. In this case the central generator can be identified with the usual Calogero-Moser Hamiltonian associated with the Coxeter group in the harmonic confinement.

  8. Phonons with orbital angular momentum

    International Nuclear Information System (INIS)

    Ayub, M. K.; Ali, S.; Mendonca, J. T.

    2011-01-01

    Ion accoustic waves or phonon modes are studied with orbital angular momentum (OAM) in an unmagnetized collissionless uniform plasma, whose constituents are the Boltzmann electrons and inertial ions. For this purpose, we have employed the fluid equations to obtain a paraxial equation in terms of ion density perturbations and discussed its Gaussian beam and Laguerre-Gauss (LG) beam solutions. Furthermore, an approximate solution for the electrostatic potential problem is presented, allowing to express the components of the electric field in terms of LG potential perturbations. The energy flux due to phonons is also calculated and the corresponding OAM is derived. Numerically, it is shown that the parameters such as azimuthal angle, radial and angular mode numbers, and beam waist, strongly modify the profiles of the phonon LG potential. The present results should be helpful in understanding the phonon mode excitations produced by Brillouin backscattering of laser beams in a uniform plasma.

  9. Angular momentum in QGP holography

    Directory of Open Access Journals (Sweden)

    Brett McInnes

    2014-10-01

    Full Text Available The quark chemical potential is one of the fundamental parameters describing the quark–gluon plasma produced by sufficiently energetic heavy-ion collisions. It is not large at the extremely high temperatures probed by the LHC, but it plays a key role in discussions of the beam energy scan programmes at the RHIC and other facilities. On the other hand, collisions at such energies typically (that is, in peripheral collisions give rise to very high values of the angular momentum density. Here we explain that holographic estimates of the quark chemical potential of a rotating sample of plasma can be very considerably improved by taking the angular momentum into account.

  10. AngularJS test-driven development

    CERN Document Server

    Chaplin, Tim

    2015-01-01

    This book is for developers who want to learn about AngularJS development by applying testing techniques. You are assumed to have a basic knowledge and understanding of HTML, JavaScript, and AngularJS.

  11. Herbig Ae/Be Star Disks at High Angular Resolution

    NARCIS (Netherlands)

    Dullemond, C.P.; Dominik, C.; van Boekel, R.J.H.M.; Waters, L.B.F.M.; van den Ancker, M.; Burton, M.; Jayawardhana, R.; Bourke, J.

    2004-01-01

    We show that there exists a simple geometric picture for the geometries of protoplanetary disks around Herbig Ae/Be stars that explains the two main kinds of spectral energy distributions found for these objects, and that makes predictions that are qualitatively in agreement with currently available

  12. Evolved stars at high angular resolution: present and future

    Science.gov (United States)

    Paladini, Claudia

    2016-08-01

    The late evolutionary stages of stellar evolution are a key ingredient for our understanding in many fields of astrophysics, including stellar evolution and the enrichment of the interstellar medium (ISM) via stellar yields. Already the first interferometric campaigns identified evolved stars as the primary targets because of their extended and partially optically thin atmospheres, and the brightness in the infrared. Interferometric studies spanning different wavelength ranges, from visual to mid-infrared, have greatly increased our knowledge of the complex atmospheres of these objects where different dynamic processes are at play. In less than two decades this technique went from measuring simple diameters to produce the first images of stellar surfaces. By scanning the extended atmospheres we constrained theoretical models, learnt about molecular stratification, dust formation, and stellar winds, and there is still a lot to be done. In this contribution I will review the recent results that optical/infrared interferometry has made on our current understanding of cool evolved stars. The presentation will focus on asymptotic giant branch stars, and red supergiants. I will discuss the challenges of image reconstruction, and highlight how this field of research will benefit from the synergy of the current interferometric instrument(s) with the second generation VLTI facilities GRAVITY and MATISSE. Finally I will conclude with a short introspection on applications of a visible interferometer and of the the Planet Formation Imager (PFI) to the field of evolved stars.

  13. Photoelectron spectrometer for high-resolution angular resolved studies

    International Nuclear Information System (INIS)

    Parr, A.C.; Southworth, S.H.; Dehmer, J.L.; Holland, D.M.P.

    1982-01-01

    We report on a new electron spectrometer system designed for use on storage-ring light sources. The system features a large (76 cm dia. x 92 cm long) triply magnetically shielded vacuum chamber and two 10.2 cm mean radius hemispherical electron-energy analyzers. One of the analyzers is fixed and the other is rotatable through about 150 0 . The chamber is pumped by a cryopump and a turbomolecular pump combination so as to enable experiments with a variety of gases under different conditions. The light detection includes both a direct beam monitor and polarization analyzer. The electron detection is accomplished with either a continuous-channel electron multiplier or with multichannel arrays used as area detectors

  14. Angular Momentum of Topologically Structured Darkness.

    Science.gov (United States)

    Alperin, Samuel N; Siemens, Mark E

    2017-11-17

    We theoretically analyze and experimentally measure the extrinsic angular momentum contribution of topologically structured darkness found within fractional vortex beams, and show that this structured darkness can be explained by evanescent waves at phase discontinuities in the generating optic. We also demonstrate the first direct measurement of the intrinsic orbital angular momentum of light with both intrinsic and extrinsic angular momentum, and explain why the total orbital angular momenta of fractional vortices do not match the winding number of their generating phases.

  15. Network for Astronomy School Education

    Science.gov (United States)

    Deustua, Susana E.; Ros, R. M.; Garcia, B.

    2014-01-01

    The Network for Astronomy School Education Project (NASE) was developed in response to the IAU's most recent 10 Years Strategic Plan to increase the efforts of the IAU in schools. NASE's mission is to stimulate teaching astronomy in schools, through professional development of primary and secondary school science teachers in developing and emerging countries. NASE's organizational principle is to build capacity by providing courses for three years in cooperation with a Local Organizing Committee (Local NASE Group). The Local NASE Group consists of 6-8 local university professors and education professional who will promote astronomy activities and organize future courses in subsequent years in their region of their country. NASE philosophy is to introduce low-tech astronomy, and has thus developed an a suite of activities that can be carried out with inexpensive, quotidian materials. Supporting these activities is a text for teachers, plus a complete set of instructional materials for each topic. These materials are available in English and Spanish, with future editions available in Chinese and Portuguese. We describe and discuss NASE activities in Central and South America from 2009 to the present.

  16. Utrecht and Galactic Radio Astronomy

    NARCIS (Netherlands)

    van Woerden, H.

    Important roles in early Dutch Galactic radio astronomy were played by several Utrecht astronomers: Van de Hulst, Minnaert and Houtgast. The poster announcing the conference contained a number of pictures referring to scientific achievements of the Astronomical Institute Utrecht. One of these

  17. Service Learning in Introductory Astronomy

    Science.gov (United States)

    Orleski, Michael

    2013-01-01

    Service learning is a method of instruction where the students in a course use the course's content in a service project. The service is included as a portion of the students' course grades. During the fall semester 2010, service learning was incorporated into the Introduction to Astronomy course at Misericordia University. The class had eight…

  18. Astronomy Education for Physics Students

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Now, astrophysics has become a key subject in Guangdong Province, and the Astronomy Science and Technology Research Laboratory one of the key laboratories of the Department of Education of the Guangdong Province. Many undergraduate students, working under the tutorship of faculty members ...

  19. Encyclopedia of Astronomy and Astrophysics

    CERN Document Server

    2002-01-01

    Interstellar medium, Light, Magnetisphere, Matter, Planet Earth, Public Impact, Solar Activity, Solar Heliosphere, Solar Interior, Solar Systems, Space, Stellar Astrophysics, Stellar Populations, Telescopes, Time The Encyclopedia of Astronomy and Astrophysics covers 30 major subject areas, such as Active galaxies, Astrometry, Astrophysical theory, Atmospheres, Binary stars, Biography, Clusters, Coordinates, Cosmology, Earth, Education, Galaxies,

  20. Visual lunar and planetary astronomy

    CERN Document Server

    Abel, Paul G

    2013-01-01

    With the advent of CCDs and webcams, the focus of amateur astronomy has to some extent shifted from science to art. The object of many amateur astronomers is now to produce “stunning images” that, although beautiful, are not intended to have scientific merit. Paul Abel has been addressing this issue by promoting visual astronomy wherever possible – at talks to astronomical societies, in articles for popular science magazines, and on BBC TV’s The Sky at Night.   Visual Lunar and Planetary Astronomy is a comprehensive modern treatment of visual lunar and planetary astronomy, showing that even in the age of space telescopes and interplanetary probes it is still possible to contribute scientifically with no more than a moderately priced commercially made astronomical telescope.   It is believed that imaging and photography is somehow more objective and more accurate than the eye, and this has led to a peculiar “crisis of faith” in the human visual system and its amazing processing power. But by anal...

  1. Astronomy Education Challenges in Egypt

    Science.gov (United States)

    El Fady Beshara Morcos, Abd

    2015-08-01

    One of the major challenges in Egypt is the quality of education. Egypt has made significant progress towards achieving the Education for All and the Millennium Development Goals (MDGs). Many associations and committees as education reform program and education support programs did high efforts in supporting scientific thinking through the scientific clubs. The current state of astronomical education in Egypt has been developed. Astronomy became a part in both science and geography courses of primary, preparatory and secondary stages. Nowadays the Egyptian National Committee for Astronomy, put on its shoulders the responsibility of revising of astronomy parts in the education courses, beside preparation of some training programs for teachers of different stages of educations, in collaboration with ministry of education. General lectures program has been prepared and started in public places , schools and universities. Many TV and Radio programs aiming to spread astronomical culture were presented. In the university stage new astronomy departments are established and astrophysics courses are imbedded in physics courses even in some private universities.

  2. AngularJS web application development

    CERN Document Server

    Darwin, Peter Bacon

    2013-01-01

    The book will be a step-by-step guide showing the readers how to build a complete web app with AngularJSJavaScript developers who want to learn AngularJS for developing web apps. Knowledge of JavaScript and HTML is expected. No knowledge of AngularJS is required.

  3. Power calculation of linear and angular incremental encoders

    Science.gov (United States)

    Prokofev, Aleksandr V.; Timofeev, Aleksandr N.; Mednikov, Sergey V.; Sycheva, Elena A.

    2016-04-01

    Automation technology is constantly expanding its role in improving the efficiency of manufacturing and testing processes in all branches of industry. More than ever before, the mechanical movements of linear slides, rotary tables, robot arms, actuators, etc. are numerically controlled. Linear and angular incremental photoelectric encoders measure mechanical motion and transmit the measured values back to the control unit. The capabilities of these systems are undergoing continual development in terms of their resolution, accuracy and reliability, their measuring ranges, and maximum speeds. This article discusses the method of power calculation of linear and angular incremental photoelectric encoders, to find the optimum parameters for its components, such as light emitters, photo-detectors, linear and angular scales, optical components etc. It analyzes methods and devices that permit high resolutions in the order of 0.001 mm or 0.001°, as well as large measuring lengths of over 100 mm. In linear and angular incremental photoelectric encoders optical beam is usually formulated by a condenser lens passes through the measuring unit changes its value depending on the movement of a scanning head or measuring raster. Past light beam is converting into an electrical signal by the photo-detecter's block for processing in the electrical block. Therefore, for calculating the energy source is a value of the desired value of the optical signal at the input of the photo-detecter's block, which reliably recorded and processed in the electronic unit of linear and angular incremental optoelectronic encoders. Automation technology is constantly expanding its role in improving the efficiency of manufacturing and testing processes in all branches of industry. More than ever before, the mechanical movements of linear slides, rotary tables, robot arms, actuators, etc. are numerically controlled. Linear and angular incremental photoelectric encoders measure mechanical motion and

  4. Schiaparelli and the dawn of astronomy

    Science.gov (United States)

    Antonello, E.

    Schiaparelli is remembered by astronomers and scholars interested in ancient astronomy in particular for his fundamental contributions to the understanding of ancient Greek astronomy and for his pioneer work on babylonian astronomy. In the present paper we will highlight some of his studies and ideas about: a) the origins and the primitive astronomy in the context of the european archaeology and anthropology researches, b) the problems in the analysis of a cuneiform tablet, and c) the interpretation of the astronomical content of a verse in the Old Testament, with an interesting implication for the present day researches in cultural astronomy and archaeoastronomy.

  5. Research on teaching astronomy in the planetarium

    CERN Document Server

    Slater, Timothy F

    2017-01-01

    From a noted specialist in astronomy education and outreach, this Brief provides an overview of the most influential discipline-based science education research literature now guiding contemporary astronomy teaching. In recent years, systematic studies of effective and efficient teaching strategies have provided a solid foundation for enhancing college-level students’ learning in astronomy. Teaching astronomy and planetary science at the college-level was once best characterized as professor-centered, information-download lectures. Today, astronomy faculty are striving to drastically improve the learning environment by using innovative teaching approaches.  Uniquely, the authors have organized this book around strands of commonly employed astronomy teaching strategies to help readers, professors, and scholars quickly access the most relevant work while, simultaneously, avoiding the highly specialized, technical vocabulary of constructivist educational pedagogies unfamiliar to most astronomy professors. F...

  6. Novel Photosensor "ReFerence" for Ground-Based Gamma-Ray Astronomy and Water Cherenkov Neutrino Physics

    Science.gov (United States)

    Ferenc, Daniel; Laille, Alvin; Bratton, Clayton

    2002-04-01

    A novel photosensor concept "ReFerence" was invented in order to provide multiple increase in the detection efficiency of Cherenkov photons in ground-based atmospheric Cherenkov Telescopes (ACT). The particular goal was to lower the gamma-ray detection threshold of the MAGIC telescope down to about 10 GeV. The "ReFerence" photosensor concept is unique in providing: more than twofold increase in quantum efficiency compared to photomultiplier tubes (PMT), excellent single-photon resolution (just as in HPDs), diminished thermionic noise, unprecedented magnetic shielding, negligible dead area, flat angular acceptance with sharp cutoff, hexagonal packing into large-area flat-panel cameras, manifest conceptual and constructional simplicity, extreme robustness and implosion safety, and low price. An extension of the "ReFerence" concept, the so called "TransReFerence", provides two very important additional (even originally unexpected) features - single-photon color sensitivity without destructive filtering, and multiple extension of the spectral sensitivity range. First "ReFerence" photosensor prototype was recently constructed and tested at UC Davis, and the results have verified the "ReFerence" concept. Development of a new fully functional prototype, based on super-sensitive GaAs-type photocathodes, has recently started in collaboration with the ITT Night Vision Industries. In this talk we will summarise the "ReFerence" concept, discuss its benefits for gamma-ray astronomy, and present the latest results of prototype tests.

  7. Optical angular momentum in classical electrodynamics

    Science.gov (United States)

    Mansuripur, Masud

    2017-06-01

    Invoking Maxwell’s classical equations in conjunction with expressions for the electromagnetic (EM) energy, momentum, force, and torque, we use a few simple examples to demonstrate the nature of the EM angular momentum. The energy and the angular momentum of an EM field will be shown to have an intimate relationship; a source radiating EM angular momentum will, of necessity, pick up an equal but opposite amount of mechanical angular momentum; and the spin and orbital angular momenta of the EM field, when absorbed by a small particle, will be seen to elicit different responses from the particle.

  8. Dependency injection with AngularJS

    CERN Document Server

    Knol, Alex

    2013-01-01

    This book is a practical, hands-on approach to using dependency injection and implementing test-driven development using AngularJS. Dependency Injection with AngularJS is aimed at developers who are aware of AngularJS but need to get started with using it in real life applications. Also, developers who want to get into test-driven development with AngularJS can use this book as practical guide. Even if you know about dependency injection, it can serve as a good reference on how it is used within AngularJS. Readers are expected to have some experience with JavaScript.

  9. Astronomy Village: Innovative Uses of Planetary Astronomy Images and Data

    Science.gov (United States)

    Croft, S. K.; Pompea, S. M.

    2008-06-01

    Teaching and learning science is best done by hands-on experience with real scientific data and real scientific problems. Getting such experiences into public and home-schooling classrooms is a challenge. Here we describe two award-winning multimedia products that embody one successful solution to the problem: Astronomy Village: Investigating the Universe, and Astronomy Village: Investigating the Solar System. Each Village provides a virtual environment for inquiry-based scientific exploration of ten planetary and astronomical problems such as ``Mission to Pluto'' and ``Search for a Supernova.'' Both Villages are standards-based and classroom tested. Investigating the Solar System is designed for middle and early high school students, while Investigating the Universe is at the high school and introductory college level. The objective of both Villages is to engage students in scientific inquiry by having them acquire, explore, and analyze real scientific data and images drawn from real scientific problems.

  10. Spatial Angular Compounding Technique for H-Scan Ultrasound Imaging.

    Science.gov (United States)

    Khairalseed, Mawia; Xiong, Fangyuan; Kim, Jung-Whan; Mattrey, Robert F; Parker, Kevin J; Hoyt, Kenneth

    2018-01-01

    H-Scan is a new ultrasound imaging technique that relies on matching a model of pulse-echo formation to the mathematics of a class of Gaussian-weighted Hermite polynomials. This technique may be beneficial in the measurement of relative scatterer sizes and in cancer therapy, particularly for early response to drug treatment. Because current H-scan techniques use focused ultrasound data acquisitions, spatial resolution degrades away from the focal region and inherently affects relative scatterer size estimation. Although the resolution of ultrasound plane wave imaging can be inferior to that of traditional focused ultrasound approaches, the former exhibits a homogeneous spatial resolution throughout the image plane. The purpose of this study was to implement H-scan using plane wave imaging and investigate the impact of spatial angular compounding on H-scan image quality. Parallel convolution filters using two different Gaussian-weighted Hermite polynomials that describe ultrasound scattering events are applied to the radiofrequency data. The H-scan processing is done on each radiofrequency image plane before averaging to get the angular compounded image. The relative strength from each convolution is color-coded to represent relative scatterer size. Given results from a series of phantom materials, H-scan imaging with spatial angular compounding more accurately reflects the true scatterer size caused by reductions in the system point spread function and improved signal-to-noise ratio. Preliminary in vivo H-scan imaging of tumor-bearing animals suggests this modality may be useful for monitoring early response to chemotherapeutic treatment. Overall, H-scan imaging using ultrasound plane waves and spatial angular compounding is a promising approach for visualizing the relative size and distribution of acoustic scattering sources. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

  11. End of the Golden Age for X-ray Astronomy: Technical and Fiscal Challenges

    Science.gov (United States)

    Elvis, Martin

    2012-09-01

    Golden Ages don't last much more than 50 years (viz. Athens 4th century BCE, Renaissance Italy, Dutch Golden Age) - that's why they're golden. X-ray astronomy is now 50 years old. Should we expect it to continue to flourish? Or is this the end of our Golden Age? Technologically there is tremendous promise. New optics and detectors are set to deliver great improvements along all axes: collecting area, angular and spectral resolution, field of view, polarimetry. To be optimal along a given axis, missions should not try to combine all these improvements in a single mission. Hence specialized missions of modest size (similar to NASA's Explorer class) should be pursued world-wide. Multiple missions also support a wide, varied, and creative community, not only of observers but also of instrument builders, operations staff and data/archive developers. All are necessary for a healthy field. We should encourage our agencies to adopt vigorous modest-mission programs, and to encourage open access to promote intellectual creativity. But some axes are almost certainly out of reach for Explorer-class missions. Most likely equaling or bettering Chandra angular resolution with larger area will require an Observatory-class, flagship, mission. While the technology is promising, the world-wide prospects for such a mission are grim. This is not merely the result of current economic woes, although they have brought the crisis to a head. Each generation of mission has to be an order of magnitude better than its predecessor in order to win funding. But to achieve this costs go up by a factor of a few each time. The progression: rockets - UHURU - Einstein - Chandra illustrates this clearly. The same exponentiation is evident in UV/visible astronomy and, perhaps, in Mars exploration. We have now hit the "funding wall" where each flagship mission costs so much that they pop into politicians notice. JWST is now a budget line item in the US, a precarious position previously held by the

  12. Multimedia Astronomy Communication: Effectively Communicate Astronomy to the Desired Audience

    Science.gov (United States)

    Star Cartier, Kimberly Michelle; Wright, Jason

    2017-01-01

    A fundamental aspect of our jobs as scientists is communicating our work to others. In this, the field of astronomy holds the double-edged sword of ubiquitous fascination: the topic has been of interest to nearly the entire global population at some point in their lives, yet the learning curve is steep within any subfield and rife with difficult-to-synthesize details. Compounding this issue is the ever-expanding array of methods to reach people in today's Communications Era. Each communication medium has its own strengths and weaknesses, is appropriate in different situations, and requires its own specific skillset in order to maximize its functionality. Despite this, little attention is given to training astronomers in effective communication techniques, often relying on newcomers to simply pick up the ability by mimicking others and assuming that a firm grasp on the subject matter will make up for deficiencies in communication theory. This can restrict astronomers to a narrow set of communication methods, harming both the communicators and the audience who may struggle to access the information through those media.Whether writing a research paper to academic peers or giving an astronomy talk to a pubic audience, successfully communicating a scientific message requires more than just an expert grasp on the topic. A communicator must understand the makeup and prior knowledge of the desired audience, be able to break down the salient points of the topic into pieces that audience can digest, select and maximize upon a medium to deliver the message, and frame the message in a way that hooks the audience and compels further interest. In this work we synthesize the requirements of effective astronomy communication into a few key questions that every communicator needs to answer. We then discuss some of the most common media currently used to communicate astronomy, give both effective and poor examples of utilizing these media to communicate astronomy, and provide key

  13. Academic Training: Gravitational Waves Astronomy

    CERN Multimedia

    2006-01-01

    2006-2007 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 16, 17, 18 October from 11:00 to 12:00 - Main Auditorium, bldg. 500 Gravitational Waves Astronomy M. LANDRY, LIGO Hanford Observatory, Richland, USA Gravitational wave astronomy is expected to become an observational field within the next decade. First direct detection of gravitational waves is possible with existing terrestrial-based detectors, and highly probable with proposed upgrades. In this three-part lecture series, we give an overview of the field, including material on gravitional wave sources, detection methods, some details of interferometric detectors, data analysis methods, and current results from observational data-taking runs of the LIGO and GEO projects. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch If you wish to participate in one of the following courses, please tell to your supervisor and apply electronically from the course description pages that can be found on the Web at: http://www...

  14. Tangible Things of American Astronomy

    Science.gov (United States)

    Schechner, Sara Jane

    2018-01-01

    As a science that studies celestial objects situated at vast distances from us, astronomy deals with few things that can be touched directly. And yet, astronomy has many tangible things—scientific instruments, observatories, and log books, for example—which link the past to the present. There is little question about maintaining things still valuable for scientific research purposes, but why should we care about documenting and preserving the old and obsolete? One answer is that material things, when closely examined, enhance our knowledge of astronomy’s history in ways that written texts alone cannot do. A second answer is that learning about the past helps us live critically in the present. In brief case studies, this talk will find meaning in objects that are extraordinary or commonplace. These will include a sundial, an almanac, telescopes, clocks, a rotating desk, photographic plates, and fly spankers.

  15. A goal-based angular adaptivity method for thermal radiation modelling in non grey media

    Science.gov (United States)

    Soucasse, Laurent; Dargaville, Steven; Buchan, Andrew G.; Pain, Christopher C.

    2017-10-01

    This paper investigates for the first time a goal-based angular adaptivity method for thermal radiation transport, suitable for non grey media when the radiation field is coupled with an unsteady flow field through an energy balance. Anisotropic angular adaptivity is achieved by using a Haar wavelet finite element expansion that forms a hierarchical angular basis with compact support and does not require any angular interpolation in space. The novelty of this work lies in (1) the definition of a target functional to compute the goal-based error measure equal to the radiative source term of the energy balance, which is the quantity of interest in the context of coupled flow-radiation calculations; (2) the use of different optimal angular resolutions for each absorption coefficient class, built from a global model of the radiative properties of the medium. The accuracy and efficiency of the goal-based angular adaptivity method is assessed in a coupled flow-radiation problem relevant for air pollution modelling in street canyons. Compared to a uniform Haar wavelet expansion, the adapted resolution uses 5 times fewer angular basis functions and is 6.5 times quicker, given the same accuracy in the radiative source term.

  16. LGBT Workplace Climate in Astronomy

    Science.gov (United States)

    Gaudi, B. S.; Danner, R.; Dixon, W. V.; Henderson, C. B.; Kay, L. E.

    2013-01-01

    The AAS Working Group on LGBTIQ Equality (WGLE) held a town hall meeting at the 220th AAS meeting in Anchorage to explore the workplace climate for LGBTIQ individuals working in Astronomy and related fields. Topics of discussion included anti-discrimination practices, general workplace climate, and pay and benefit policies. Four employment sectors were represented: industry, the federal government, private colleges, and public universities. We will summarize and expand on the town hall discussions and findings of the panel members.

  17. Astronomy in the National Parks

    Science.gov (United States)

    Nordgren, Tyler E.

    2009-01-01

    American national parks are fertile grounds for astronomy and planetary science outreach. They are some of the last remaining dark-sky sites the typical visitor (both U.S. and international) can still experience easily. An internal National Park Service (NPS) study shows a dark starry sky is an integral part of what visitors consider their park experience. As a result, the NPS Night Sky Team (a coordinated group of park rangers and astronomers) is measuring and monitoring the sky brightness over the parks in an attempt to promote within the park service protection of the night sky as a natural resource. A number of parks (e.g. Grand Canyon National Park) are currently expanding their night sky related visitor programs in order to take advantage of this resource and visitor interest. The national parks and their visitors are therefore an ideal audience fully "primed” to learn about aspects of astronomy or planetary science that can be, in any way, associated with the night sky. As one of the astronomers on the NPS Night Sky Team, I have been working with park service personnel on ways to target park visitors for astronomical outreach. The purpose of this outreach is twofold: 1) Strengthen popular investment in preserving dark skies, 2) Strengthen popular investment in current astronomical research. A number of avenues already being used to introduce astronomy outreach into the parks (beyond the simple "star party") will be presented.

  18. Angular Positioning Sensor for Space Mechanisms

    Science.gov (United States)

    Steiner, Nicolas; Chapuis, Dominique

    2013-09-01

    Angular position sensors are used on various rotating mechanisms such as solar array drive mechanisms, antenna pointing mechanisms, scientific instruments, motors or actuators.Now a days, potentiometers and encoders are mainly used for angular measurement purposes. Both of them have their own pros and cons.As alternative, Ruag Space Switzerland Nyon (RSSN) is developing and qualifying two innovative technologies of angular position sensors which offer easy implementation, medium to very high lifetime and high flexibility with regards to the output signal shape/type.The Brushed angular position sensor uses space qualified processes which are already flying on RSSN's sliprings for many years. A large variety of output signal shape can be implemented to fulfill customer requirements (digital, analog, customized, etc.).The contactless angular position sensor consists in a new radiation hard Application Specific Integrated Circuit (ASIC) based on the Hall effect and providing the angular position without complex processing algorithm.

  19. Photometric Exoplanet Characterization and Multimedia Astronomy Communication

    Science.gov (United States)

    Cartier, Kimberly M. S.

    The transit method of detecting exoplanets has dominated the search for distant worlds since the success of the Kepler space telescope and will continue to lead the field after the launch of the Transiting Exoplanet Survey Satellite in 2018. But detections are just the beginning. Transit light curves can only reveal a limited amount of information about a planet, and that information is almost entirely dependent on the properties of the host star or stars. This dissertation discusses follow-up techniques to more precisely characterize transiting planets using photometric observations. A high-resolution follow-up imaging program using the Hubble Space Telescope (HST) searched for previously unknown stars nearby the hosts of small and cool Kepler exoplanets and observed a higher-than-expected occurrence rate of stellar multiplicity. The rate of previously unknown stellar multiples has strong implications for the size and habitability of the orbiting planets. Three systems with newly discovered stellar multiplicity, Kepler-296 (2 stars, 5 planets), KOI-2626 (3 stars, 1 planet), and KOI-3049 (2 stars, 1 planet), were characterized in more detail. In the cases of Kepler-296 and KOI-2626, some of the planets lost their previous habitable zone status because of host star ambiguity. Next, the ultra-short period, ultra-hot Jupiter WASP-103b was used as a casestudy to test for the presence of a stratospheric temperature inversion through dayside emission spectroscopy using HST. WASP-103b's near-infrared emission spectrum is consistent with an isothermal or thermally-inverted atmosphere and shows no significant broadband water absorption feature. Detection of an anomalously strong "super- Rayleigh" slope in its optical transmission spectrum prompted follow-up transmission spectroscopy of WASP-103b's atmosphere using the MINiature Radial Velocity Array (MINERVA), which tentatively verified the unexplained "super-Rayleigh" spectral slope. The final follow-up technique for

  20. Cultural Astronomy in the Armenian Highland

    Science.gov (United States)

    Farmanyan, S. V.; Suvaryan, Yu. M.; Mickaelian, A. M. (Eds.)

    2016-12-01

    The book contains 29 articles of the Proceedings of the Young Scientists Conference "Cultural Astronomy in the Armenian Highland" held at the Armenian National Academy of Sciences on 20-23 June 2016. It consists of 4 main sections: "Introductory", "Cultural Astronomy", "Archaeoastronomy", "Scientific Tourism and Journalism, Astronomical Education and Amateur Astronomy". The book may be interesting to astronomers, culturologists, philologists, linguists, historians, archaeologists, art historians, ethnographers and to other specialists, as well as to students.

  1. Julia and Python in Astronomy: Better Together

    Science.gov (United States)

    Barbary, Kyle

    2016-03-01

    Astronomers love Python because it is open source, easy to learn, and has a tremendous ecosystem for scientific computing. The Julia programming language has many of those same characteristics. In this talk, I'll discuss the use of Julia in astronomy and the growing ecosystem of astronomy packages, particularly those managed by the JuliaAstro organization (http://JuliaAstro.github.io). Most importantly, I will highlight some areas ripe for collaboration between Python and Julia developers in astronomy.

  2. Oral candidiasis and angular cheilitis.

    Science.gov (United States)

    Sharon, Victoria; Fazel, Nasim

    2010-01-01

    Candidiasis, an often encountered oral disease, has been increasing in frequency. Most commonly caused by the overgrowth of Candida albicans, oral candidiasis can be divided into several categories including acute and chronic forms, and angular cheilitis. Risk factors for the development of oral candidiasis include immunosuppression, wearing of dentures, pharmacotherapeutics, smoking, infancy and old age, endocrine dysfunction, and decreased salivation. Oral candidiasis may be asymptomatic. More frequently, however, it is physically uncomfortable, and the patient may complain of burning mouth, dysgeusia, dysphagia, anorexia, and weight loss, leading to nutritional deficiency and impaired quality of life. A plethora of antifungal treatments are available. The overall prognosis of oral candidiasis is good, and rarely is the condition life threatening with invasive or recalcitrant disease.

  3. Management of angular cheilitis for children

    Directory of Open Access Journals (Sweden)

    Fajriani Fajriani

    2016-06-01

    Full Text Available Angular cheilitis is one type of oral soft tissue disease that can occur in both children and adults, the condition is characterized by cracks and inflammation in both corners of the mouth. Although this disease does not cause severe disruption but quite disturbing activity and also one's physical appearance. Angular cheilitis light will disappear on their own over time.Severe conditions that can cause pain and bleading. aims to give feedback on peers about managment angular cheilitis in children.

  4. Improving Astronomy Achievement and Attitude through Astronomy Summer Project: A Design, Implementation and Assessment

    Science.gov (United States)

    Türk, Cumhur; Kalkan, Hüseyin; Iskeleli', Nazan Ocak; Kiroglu, Kasim

    2016-01-01

    The purpose of this study is to examine the effects of an astronomy summer project implemented in different learning activities on elementary school students, pre-service elementary teachers and in-service teachers' astronomy achievement and their attitudes to astronomy field. This study is the result of a five-day, three-stage, science school,…

  5. The Relationship between Preservice Science Teachers' Attitude toward Astronomy and Their Understanding of Basic Astronomy Concepts

    Science.gov (United States)

    Bektasli, Behzat

    2016-01-01

    Turkish preservice science teachers have been taking a two-credit astronomy class during the last semester of their undergraduate program since 2010. The current study aims to investigate the relationship between preservice science teachers' astronomy misconceptions and their attitudes toward astronomy. Preservice science teachers were given an…

  6. A New Online Astronomy Resource for Education and Outreach

    Science.gov (United States)

    Impey, C. D.; Hardegree-Ullman, K. K.; Patikkal, A.; Srinathan, A.; Austin, C. L.; Ganesan, N. K.; Guvenen, B. C.

    2013-01-01

    A new web site called "Teach Astronomy" (http://www.teachastronomy.com) has been created to serve astronomy instructors and their students, amateur astronomers, and members of the public interested in astronomy. The

  7. Beating the diffraction limit in astronomy via quantum cloning

    Science.gov (United States)

    Kellerer, A.

    2014-01-01

    Context. The diffraction limit is considered as the absolute boundary for the angular resolution of a telescope. Non-linear optical processes, however, allow the diffraction limit to be beaten non-deterministically. Aims: We examine the possibility of overcoming the diffraction limit of a telescope through photon cloning processes, heralded by trigger events. Whilst perfect cloning is ruled out by quantum mechanics, imperfect cloning is attainable and can beat the diffraction limit on a reduced fraction of photons. Methods: We suggest to insert a layer of excited atoms in a pupil plane of the telescope. When a photon from the astronomical source passes the pupil, it stimulates the emission of identical photons by the excited atoms. The set of photons arrives on a coincidence detector, and the average position of simultaneously arriving photons is recorded. The contribution of spontaneous emissions is minimized by use of a trigger signal, implemented via a quantum-non-demolition measurement. Results: The proposed set-up - an optical amplifier triggered by a quantum-non-demolition measurement - allows to beat the diffraction limit of a telescope, at the price of a loss in efficiency. The efficiency may, however, be compensated for through increased exposure times. Conclusions: The main conclusion is the possibility in principle to improve the angular resolution of a telescope beyond the diffraction limit and thus to achieve high-angular resolutions with moderately sized telescopes.

  8. Transverse and longitudinal angular momenta of light

    Energy Technology Data Exchange (ETDEWEB)

    Bliokh, Konstantin Y., E-mail: k.bliokh@gmail.com [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Nonlinear Physics Centre, RSPhysE, The Australian National University, Canberra, ACT 0200 (Australia); Nori, Franco [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2015-08-26

    We review basic physics and novel types of optical angular momentum. We start with a theoretical overview of momentum and angular momentum properties of generic optical fields, and discuss methods for their experimental measurements. In particular, we describe the well-known longitudinal (i.e., aligned with the mean momentum) spin and orbital angular momenta in polarized vortex beams. Then, we focus on the transverse (i.e., orthogonal to the mean momentum) spin and orbital angular momenta, which were recently actively discussed in theory and observed in experiments. First, the recently-discovered transverse spin  angular momenta appear in various structured fields: evanescent waves, interference fields, and focused beams. We show that there are several kinds of transverse spin angular momentum, which differ strongly in their origins and physical properties. We describe extraordinary features of the transverse optical spins and overview recent experiments. In particular, the helicity-independent transverse spin inherent in edge evanescent waves offers robust spin–direction coupling at optical interfaces (the quantum spin Hall effect of light). Second, we overview the transverse orbital angular momenta of light, which can be both extrinsic and intrinsic. These two types of the transverse orbital angular momentum are produced by spatial shifts of the optical beams (e.g., in the spin Hall effect of light) and their Lorentz boosts, respectively. Our review is underpinned by a unified theory of the angular momentum of light based on the canonical momentum and spin densities, which avoids complications associated with the separation of spin and orbital angular momenta in the Poynting picture. It allows us to construct a comprehensive classification of all known optical angular momenta based on their key parameters and main physical properties.

  9. Music and Astronomy Under the Stars 2009

    Science.gov (United States)

    Lubowich, D.

    2010-08-01

    Bring telescopes to where the people are! Music and Astronomy Under the Stars is a three-year NASA-funded astronomy outreach program at community parks during and after music concerts and outdoor family events—such as a Halloween Stars-Spooky Garden Walk. While there have been many astronomy outreach activities and telescope observations at city sidewalks and parks, this program targets a completely different audience: music lovers who are attending summer concerts held in community parks. These music lovers who may never have visited a science museum, planetarium, or star party are exposed to telescope observations and astronomy information with no additional travel costs. Music and Astronomy Under the Stars increased awareness, engagement, and interest in astronomy at classical, pop, rock, and ethnic music concerts. This program includes solar observing before the concerts, telescope observations including a live image projection system, an astronomical video presentation, and astronomy banners/posters. Approximately 500-16,000 people attended each event and 25% to 50% of the people at each event participated in the astronomy program. This program also reached underrepresented and underserved groups (women, minorities, older adults). The target audience (Nassau and Suffolk Counties, New York) is 2,900,000 people, which is larger than combined population of Atlanta, Boston, Denver, Minneapolis, and San Francisco. Although eleven events were planned in 2009, two were canceled due to rain and our largest event, the NY Philharmonic in the Park (attended by 67,000 people in 2008), was cancelled for financial reasons. Our largest event in 2009 was the Tanglewood Music Festival, Lenox MA, attended by 16,000 people where over 5000 people participated in astronomy activities. The Amateur Observers' Society of New York assisted with the NY concerts and the Springfield STARS astronomy club assisted at Tanglewood. In 2009 over 15,000 people participated in astronomy

  10. Copernican Astronomy and Oceanic Exploration

    Science.gov (United States)

    McKittrick, Paul

    2014-01-01

    This paper examines the relationships between the century long development of the “New Astronomy” (Copernicus’ axially rotating and solar orbiting earth, governed by Kepler’s laws of planetary motion) of the sixteenth and early seventeenth centuries and the emerging astronomical navigation technologies of the fifteenth and sixteenth century Iberian oceanic explorers and their sixteenth and seventeenth century Protestant competitors. Since the first breakthroughs in Portuguese astronomical navigation in ascertaining latitude at sea were based upon the theories and observations of classically trained Ptolemaic astronomers and cosmographers, it can be argued that the new heliocentric astronomy was not necessary for future developments in early modern navigation. By examining the history of the concurrent revolutions in early modern navigation and astronomy and focusing upon commonalities, we can identify the period during which the old astronomy provided navigators with insufficient results - perhaps hastening the acceptance of the new epistemology championed by Galileo and rejected by Bellarmine. Even though this happened during the period of northern protestant ascendancy in exploration, its roots can be seen during pre-Copernican acceptance in both Lutheran and Catholic Europe. Copernican mathematics was used to calculate Reinhold’s Prutenic Tables despite the author’s ontological rejection of the heliocentric hypothesis. These tables became essential for ascertaining latitude at sea. Kepler’s Rudophine Tables gained even more widespread currency across Europe. His theories were influenced by Gilbert’s work on magnetism - a work partially driven by the requirements of English polar exploration. Sailors themselves never needed to accept a heliocentric cosmography, but the data they brought back to the metropolis undermined Ptolemy, as better data kept them alive at sea. This exchange between theoretician and user in the early modern period drove both

  11. Q0000-398 is a high-redshift quasar with a large angular size

    International Nuclear Information System (INIS)

    Gearhart, M.R.; Pacht, E.

    1977-01-01

    A study is described, using the three-element interferrometer at the National Radio Astronomy Observatory, West Virginia, to investigate whether any quasars exist that might be radio sources. It was found that Q0000-398 appeared to be a quasar of high red shift and large angular size. The interferrometer was operated with a 300-1200-1500 m baseline configuration at 2695 MHz. The radio map for Q0000-398 is shown, and has two weak components separated by 134 +- 40 arc s. If these components are associated with the optical object this quasar has the largest known angular size for its red shift value. The results reported for Q0000-398 and other quasars having considerable angular extent demonstrate the importance of considering radio selection effects in the angular diameter-red shift relationship, and since any radio selection effects are removed when quasars are selected optically, more extensive mapping programs should be undertaken, looking particularly for large scale structure around optically selected high-z quasars. (U.K.)

  12. Astronomy Map of the World

    Science.gov (United States)

    Veras, D.

    2017-09-01

    I have created an online clickable and zoom-enabled world map - now viewed over 5,400 times - that contains weblinks to institutions where astronomy is either researched professionally and / or and taught in classrooms at the university level. Not included are stand-alone museums, planetariums, amateur astronomical societies, virtual institutes, nor observatories which do not fulfill this criteria. One can click on a marker to access the relevant institute. The map currently contains 697 institutes, and has multiple potential uses for undergraduate students, graduate students, postdocs, faculty and journal editors.

  13. Highlights of Astronomy, Vol. 15

    Science.gov (United States)

    Corbett, Ian

    2010-11-01

    Preface; Part I. Gruber Cosmology Prize Lecture; Part II. Invited Discourses; Part III. Joint Discussions: 1. Dark matter in early-type galaxies Léon V. E. Koopmans and Tommaso Treu; 2. Diffuse light in galaxy clusters Magda Arnaboldi and Ortwin Gerhard; 3. Neutron stars - timing in extreme environments Tomaso Belloni, Mariano Méndez and Chengmin Zhang; 4. Progress in understanding the physics of Ap and related stars Margarida Cunha; 5. Modelling the Milky Way in the age of Gaia Annie C. Robin; 6. Time and astronomy Pascale Defraigne; 7. Astrophysical outflows and associated accretion phenomena Elisabete M. de Gouveia Dal Pino and Alex C. Raga; 8. Hot interstellar matter in elliptical galaxies Dong-Woo Kim and Silvia Pellegrini; 9. Are the fundamental constants varying with time? Paolo Molaro and Elisabeth Vangioni; 10. 3D views on cool stellar atmospheres - theory meets observation K. N. Nagendra, P. Bonifacio and H. G. Ludwig; 11. New advances in helio- and astero-seismology; 12. The first galaxies - theoretical predictions and observational clues; 13. Eta Carinae in the context of the most massive stars Theodore R. Gull and Augusto Damineli; 14. The ISM of galaxies in the far-infrared and sub-millimetre; 15. Magnetic fields in diffuse media Elisabete M. de Gouveia Dal Pino and Alex Lazarian; 16. IHY global campaign - whole heliosphere interval; Part IV. Special Sessions: SpS 1. IR and sub-mm spectroscopy - a new tool for studying stellar evolution Glenn Wahlgren, Hans Käufl and Florian Kerber; SpS 2. The international year of astronomy Pedro Russo, Catherine Cesarsky and Lars Lindberg Christensen; SpS 3. Astronomy in Antarctica in 2009 Michael G. Burton; SpS 4. Astronomy education between past and future J. P. De Greve; SpS 5. Accelerating the rate of astronomical discovery Ray P. Norris; SpS 6. Planetary systems as potential sites for life Régis Courtin, Alan Boss and Michel Mayor; SpS 7. Young stars, brown dwarfs, and protoplanetary disks Jane Gregorio

  14. CD-ROMs in Astronomy

    Science.gov (United States)

    Robertson, K.

    The CD-ROM has become a major data storage medium in astronomy. The release of the Digitized Sky Survey is the most recent example of this phenomena. I will summarize the large scale jukebox technologies available for making the DSS available over LANs (Local Area Networks). I will also give an overview of the developments in disciplines such as medicine, chemistry and business, where CD-ROMs have been used to distribute the full text of journals. These factors may give us insights into the future role of CD-ROMs.

  15. Fallacies in astronomy and medicine

    International Nuclear Information System (INIS)

    Salpeter, Edwin E

    2005-01-01

    Both in astronomy and in medicine research, fallacies occur occasionally. Sometimes these fallacies are due to 'subconscious cheating' or the 'file drawer effect' (filing away unfavourable results instead of publishing), but it is difficult to know whether a fallacy has occurred and, if so, why. I give two examples from the past where, in my opinion, fallacies have occurred: a quadratic distance-redshift law and a periodicity in galaxy pair redshift differences. I then discuss the current quasi steady state cosmology, which is very unorthodox but it is not yet clear if fallacies have occurred. I finish with examples from medicine research, where fallacies are particularly troublesome and some countermeasures are attempted

  16. The handy astronomy answer book

    CERN Document Server

    Liu, PhD, Charles

    2013-01-01

    From planetary movements and the exploration of our solar system to black holes and dark matter, this comprehensive reference simplifies all aspects of astronomy with an approachable question-and-answer format. With chapters broken into various astronomical studies—including the universe, galaxies, planets, and space exploration—this fully updated resource is an ideal companion for students, teachers, and amateur astronomers, answering more than 1,000 questions, such as Is the universe infinite? What would happen to you if you fell onto a black hole? What are the basic concepts of Einstein's special theory of relativity? and Who was the first person in space?.

  17. Astronomy Data Visualization with Blender

    Science.gov (United States)

    Kent, Brian R.

    2015-08-01

    We present innovative methods and techniques for using Blender, a 3D software package, in the visualization of astronomical data. N-body simulations, data cubes, galaxy and stellar catalogs, and planetary surface maps can be rendered in high quality videos for exploratory data analysis. Blender's API is Python based, making it advantageous for use in astronomy with flexible libraries like astroPy. Examples will be exhibited that showcase the features of the software in astronomical visualization paradigms. 2D and 3D voxel texture applications, animations, camera movement, and composite renders are introduced to the astronomer's toolkit and how they mesh with different forms of data.

  18. Angular momentum transfer in incomplete fusion

    Indian Academy of Sciences (India)

    fusion reactions. The angular momentum of the intermediate nucleus formed in incomplete fusion was deduced from the isomeric cross-section ratio by considering the statistical de- excitation of the incompletely fused composite nucleus. The data show that incomplete fusion is associated with angular momenta slightly ...

  19. Responsive web design with AngularJS

    CERN Document Server

    Patel, Sandeep Kumar

    2014-01-01

    If you are an AngularJS developer who wants to learn about responsive web application development, this book is ideal for you. Responsive Web Design with AngularJS is intended for web developers or designers with a basic knowledge of HTML, CSS, and JavaScript.

  20. Angular momentum transfer in incomplete fusion

    Indian Academy of Sciences (India)

    The angular momentum of the intermediate nucleus formed in incomplete fusion was deduced from the isomeric cross-section ratio by considering the statistical de-excitation of the incompletely fused composite nucleus. The data show that incomplete fusion is associated with angular momenta slightly smaller than critical ...

  1. Accelerated rotation with orbital angular momentum modes

    CSIR Research Space (South Africa)

    Schulze, C

    2015-04-01

    Full Text Available A 91, 043821 (2015) Accelerated rotation with orbital angular momentum modes Christian Schulze, Filippus S. Roux, Angela Dudley, Ronald Rop, Michael Duparr´e, and Andrew Forbes Abstract: We introduce a class of light field that angularly...

  2. Dijet angular distributions at D0

    International Nuclear Information System (INIS)

    Fatyga, M.K.

    1996-09-01

    Measurements of the dijet angular distributions are relatively insensitive to parton distribution functions and thus offer an excellent method of testing the LO and NLO predictions of perturbative QCD. The authors present measurements of the dijet angular distributions for |η| < 3.0 in p anti p collisions at √s = 1.8 TeV

  3. Experimental determination of high angular momentum states

    International Nuclear Information System (INIS)

    Barreto, J.L.V.

    1985-01-01

    The current knowledge of the atomic nucleus structure is summarized. A short abstract of the nuclear properties at high angular momentum and a more detailed description of the experimental methods used in the study of high angular momenta is made. (L.C.) [pt

  4. Concepts of radial and angular kinetic energies

    DEFF Research Database (Denmark)

    Dahl, Jens Peder; Schleich, W.P.

    2002-01-01

    We consider a general central-field system in D dimensions and show that the division of the kinetic energy into radial and angular parts proceeds differently in the wave-function picture and the Weyl-Wigner phase-space picture, Thus, the radial and angular kinetic energies are different quantities...

  5. Astronomy Education in Morocco - New Project for Implementing Astronomy in High Schools

    Science.gov (United States)

    Darhmaoui, H.; Loudiyi, K.

    2006-08-01

    Astronomy education in Morocco, like in many developing countries, is not well developed and lacks the very basics in terms of resources, facilities and research. In 2004, the International Astronomical Union (IAU) signed an agreement of collaboration with Al Akhawayn University in Ifrane to support the continued, long-term development of astronomy and astrophysics in Morocco. This is within the IAU program "Teaching for Astronomy Development" (TAD). The initial focus of the program concentrated exclusively on the University's Bachelor of Science degree program. Within this program, and during two years, we were successful in providing adequate astronomy training to our physics faculty and few of our engineering students. We also offered our students and community general astronomy background through courses, invited talks and extra curricular activities. The project is now evolving towards a wider scope and seeks promoting astronomy education at the high school level. It is based on modules from the Hands on Universe (HOU) interactive astronomy program. Moroccan students will engage in doing observational astronomy from their PCs. They will have access to a world wide network of telescopes and will interact with their peers abroad. Through implementing astronomy education at this lower age, we foresee an increasing interest among our youth not only in astronomy but also in physics, mathematics, and technology. The limited astronomy resources, the lack of teachers experience in the field and the language barrier are amongst the difficulties that we'll be facing in achieving the objectives of this new program.

  6. Student Comprehension of Mathematics through Astronomy

    Science.gov (United States)

    Search, Robert

    2016-01-01

    The purpose of this study is to examine how knowledge of astronomy can enhance college-level learning situations involving mathematics. The fundamental symbiosis between mathematics and astronomy was established early in the 17th century when Johannes Kepler deduced the 3 basic laws of planetary motion. This mutually harmonious relationship…

  7. The future of astronomy in Australia

    Science.gov (United States)

    Sadler, Elaine M.

    2017-09-01

    Australian astronomy has a bright future, thanks largely to recent government investments in major new telescopes, instruments and research centres. There are some short-term challenges as Australia's focus continues to shift from the current (mainly) national facilities for radio and optical astronomy to new multinational and global facilities.

  8. Encouraging Student Participation in Large Astronomy Courses

    Science.gov (United States)

    Willoughby, Shannon D.

    2012-01-01

    Introductory astronomy is one of the most widely taught classes in the country and the majority of the students who take these classes are non-science majors. Because this demographic of students makes up the majority of astronomy enrollments, it is especially important as instructors that we do our best to make sure these students don't finish…

  9. The cost of publishing in Danish astronomy

    DEFF Research Database (Denmark)

    Dorch, Bertil F.

    I investigate the cost of publishing in Danish astronomy on a fine scale, including all direct publication costs: The figures show how the annual number of publications with authors from Denmark in astronomy journals increased by a factor approximately four during 15 years (Elsevier’s Scopus...

  10. Upsurge of X-ray astronomy 230-

    International Nuclear Information System (INIS)

    Hudec, D.R.

    1978-01-01

    Instruments are described used for X-ray astronomy, namely X-ray detectors and X-ray telescopes. Unlike telescopes, the detectors do not comprise X-ray optics. A survey is given of the results obtained in solar and stellar X-ray astronomy and hypotheses are submitted on the origin of X radiation in the interstellar space. (J.B.)

  11. Resources for Teaching Astronomy in UK Schools

    Science.gov (United States)

    Roche, Paul; Newsam, Andy; Roberts, Sarah; Mason, Tom; Baruch, John

    2012-01-01

    This article looks at a selection of resources currently available for use in the teaching of astronomy in UK schools. It is by no means an exhaustive list but it highlights a variety of free resources that can be used in the classroom to help engage students of all ages with astronomy and space science. It also lists several facilities with a…

  12. Preservice Science Teachers' Beliefs about Astronomy Concepts

    Science.gov (United States)

    Ozkan, Gulbin; Akcay, Hakan

    2016-01-01

    The purpose of this study was to investigate preservice science teachers' conceptual understanding of astronomy concepts. Qualitative research methods were used. The sample consists of 118 preservice science teachers (40 freshmen, 31 sophomores, and 47 juniors). The data were collected with Astronomy Conceptual Questionnaire (ACQ) that includes 13…

  13. Some Daytime Activities in Solar Astronomy

    Science.gov (United States)

    Burin, Michael J.

    2016-01-01

    This century's transits of Venus (2004, 2012) captured significant public attention, reminding us that the wonders of astronomy need not be confined to the night. And while nighttime telescope viewing gatherings (a.k.a. "star parties") are perennially popular, astronomy classes are typically held in the daytime. The logistics of…

  14. Communicating and Networking by Astronomy Librarians

    Science.gov (United States)

    Cummins, Marlene; Grothkopf, Uta

    Librarians in other disciplines have often marveled at the effective networking that takes place among astronomy librarians. How do we do it? In January 2001, an international survey was undertaken to assess problems, successes and trends around the world. We summarize the results as described in our publication ``Communicating and Networking in Astronomy Libraries'' (Grothkopf & Cummins 2001).

  15. Training in Astronomy for Physics Students

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In this paper, we describe what we have done with regard to astronomy training for physics students. More and more students are interested in astronomy, they spend their summer holidays and spare time in observations and studying the observation data. Some students are familiar with using the ...

  16. Julia and Python in Astronomy: Better Together

    OpenAIRE

    Barbary, Kyle

    2016-01-01

    Astronomers love Python because it is open source, easy to learn, and has a tremendous ecosystem for scientific computing. The Julia programming language has many of those same characteristics. In this talk, I discuss Julia, its use in astronomy and the growing ecosystem of astronomy packages, particularly those managed by the JuliaAstro organization (http://JuliaAstro.github.io).

  17. Techniques in X-ray Astronomy

    Indian Academy of Sciences (India)

    Techniques in X-ray Astronomy. 2. Imaging Detectors. Kulinder Pal Singh is in the Department of. Astronomy and Astro- physics of the Tata. Institute of Fundamental. Research, Mumbai. His primary fields of research are X-ray studies of hot plasmas in stars, super- nova remnants, galaxies, intergalactic medium in clusters of ...

  18. Shadow Science: Astronomy in the Schoolyard

    Science.gov (United States)

    Denney, Janice

    2005-01-01

    It is natural to study astronomy outdoors, but it is not quite as natural to study astronomy during the daytime. This lesson uses the Earth's closest star as a subject of study within the schoolyard. The importance of the rising sun is combined with hands-on inquiry in which students explore the properties of shadows. Students (a) complete a…

  19. Selected topics on data analysis in astronomy

    International Nuclear Information System (INIS)

    Scarsi, L.

    1987-01-01

    The contents of this book are: General Lectures Given at the Erice II Workshop on Data Analysis in Astronomy: Fundamentals in Data Analysis in Astronomy; Computational Techniques; Evolution of Architectures for Data Processing; Hardware for Graphics and Image Display; and Data Analysis Systems

  20. Perturbed angular correlations and distributions

    International Nuclear Information System (INIS)

    Makaryunas, K.

    1976-01-01

    The present index comprises original works and review papers on the perturbed angular correlations (PAC) and distributions (PAD). The articles published in the Soviet and foreign journals as well as the materials of conferences, monographs and collections published in the USSR and abroad, the preprints produced by various institutes and abstracts of disertations are included from 1948 up to 1973. The whole material compiled in this index is divided into three parts. Part one is a bibliographic index. All papers in this part are divided into three sections. Section one comprises the papers devoted to the theoretical works on PAC, review papers, monographs, materials of conferences. Section two deals with the works of methodical character where correlation spectrometers as well as the treatment of experimental data are described. In section three experimental works with concrete nuclei are compiled. Part two gives the characteristic of works performed with concrete nuclei. This part is presented in the form of the table in which the works are systematized according to the chemical elements and isotopes. The table shows the characteristics of the nuclear levels used in the investigations by PAC as well as brief characteristics of experiments and results obtained. Part three - appendix contains alphabetic index of the authors, the list of the used editions with the abbreviations of the titles of these editions. The lists indicating the dynamic of the quantity of works on PAC and the distribution according to the literature sources are also given

  1. Academic Training: Gravitational Waves Astronomy

    CERN Multimedia

    2006-01-01

    2006-2007 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 16, 17, 18 October from 11:00 to 12:00 - Main Auditorium, bldg. 500 Gravitational Waves Astronomy M. LANDRY, LIGO Hanford Observatory, Richland, USA Gravitational wave astronomy is expected to become an observational field within the next decade. First direct detection of gravitational waves is possible with existing terrestrial-based detectors, and highly probable with proposed upgrades. In this three-part lecture series, we give an overview of the field, including material on gravitional wave sources, detection methods, some details of interferometric detectors, data analysis methods, and current results from observational data-taking runs of the LIGO and GEO projects.ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch If you wish to participate in one of the following courses, please tell to your supervisor and apply electronically from the course description pages that can be found on the Web at: http://www.cern...

  2. γ ray astronomy with muons

    International Nuclear Information System (INIS)

    Halzen, F.; Stanev, T.; Yodh, G.B.

    1997-01-01

    Although γ ray showers are muon poor, they still produce a number of muons sufficient to make the sources observed by GeV and TeV telescopes observable also in muons. For sources with hard γ ray spectra there is a relative open-quotes enhancementclose quotes of muons from γ ray primaries as compared to that from nucleon primaries. All shower γ rays above the photoproduction threshold contribute to the number of muons N μ , which is thus proportional to the primary γ ray energy. With γ ray energy 50 times higher than the muon energy and a probability of muon production by the γ close-quote s of about 1%, muon detectors can match the detection efficiency of a GeV satellite detector if their effective area is larger by 10 4 . The muons must have enough energy for sufficiently accurate reconstruction of their direction for doing astronomy. These conditions are satisfied by relatively shallow neutrino detectors such as AMANDA and Lake Baikal, and by γ ray detectors such as MILAGRO. TeV muons from γ ray primaries, on the other hand, are rare because they are only produced by higher energy γ rays whose flux is suppressed by the decreasing flux at the source and by absorption on interstellar light. We show that there is a window of opportunity for muon astronomy with the AMANDA, Lake Baikal, and MILAGRO detectors. copyright 1997 The American Physical Society

  3. Observing Projects in Introductory Astronomy

    Science.gov (United States)

    Taylor, M. Suzanne

    2016-01-01

    Introductory astronomy classes without laboratory components face a unique challenge of how to expose students to the process of science in the framework of a lecture course. As a solution to this problem small group observing projects are incorporated into a 40 student introductory astronomy class composed primarily of non-science majors. Students may choose from 8 observing projects such as graphing the motion of the moon or a planet, measuring daily and seasonal motions of stars, and determining the rotation rate of the Sun from sunspots. Each group completes two projects, requiring the students to spend several hours outside of class making astronomical observations. Clear instructions and a check-list style observing log help students with minimal observing experience to take accurate data without direct instructor assistance. Students report their findings in a lab report-style paper, as well as in a formal oral or poster presentation. The projects serve a double purpose of allowing students to directly experience concepts covered in class as well as providing students with experience collecting, analyzing, and presenting astronomical data.

  4. Armenian Archaeoastronomy and Astronomy in Culture

    Science.gov (United States)

    Mickaelian, Areg M.; Farmanyan, Sona V.

    2016-12-01

    A review is given on archaeoastronomy in Armenia and astronomical knowledge reflected in the Armenian culture. Astronomy in Armenia was popular since ancient times and Armenia is rich in its astronomical heritage, such as the names of the constellations, ancient observatories, Armenian rock art (numerous petroglyphs of astronomical content), ancient and medieval Armenian calendars, astronomical terms and names used in Armenian language since II-I millennia B.C., records of astronomical events by ancient Armenians (e.g. Halley's comet in 87 B.C., supernovae explosion in 1054), the astronomical heritage of the Armenian medieval great thinker Anania Shirakatsi's (612-685), medieval sky maps and astronomical devices by Ghukas (Luca) Vanandetsi (XVII-XVIII centuries) and Mkhitar Sebastatsi (1676-1749), etc. For systemization and further regular studies, we have created a webpage devoted to Armenian archaeoastronomical matters at Armenian Astronomical Society (ArAS) website. Issues on astronomy in culture include astronomy in ancient Armenian cultures, ethnoastronomy, astronomy in Armenian religion and mythology, astronomy and astrology, astronomy in folklore and poetry, astronomy in arts, astrolinguistics and astroheraldry. A similar webpage for Astronomy in Armenian Culture is being created at ArAS website and a permanent section "Archaeoastronomy and Astronomy in Culture" has been created in ArAS Electronic Newsletter. Several meetings on this topic have been organized in Armenia during 2007-2014, including the archaeoastronomical meetings in 2012 and 2014, and a number of books have been published. Several institutions are related to these studies coordinated by Byurakan Astrophysical Observatory (BAO) and researchers from the fields of astronomy, history, archaeology, literature, linguistics, etc. are involved.

  5. Mass and Angular Distributions of Charged Dihadron Production

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Mary Clare [Michigan U.

    1990-01-01

    Experiment 711, conducted at Fermilab. provided a unique handle towards understanding valence quark scattering by studying pairs of single. charged, high transverse momentum hadrons produced in collisions of 800 GeV /c protons on fixed metal targets. The apparatus consisted of a double-arm spectrometer. calorimetrically triggered. with high momentum resolution and a large angular acceptance for all charge states of particle pairs. The experiment was designed to select those hadron pairs that carrted most of the momentum and energy of the underlying scattered quarks and gluons. The charge of such "leading" hadrons is correlated with the charge of the quark that produced it. Quantum Chromodynamics (QCD) assumes that the scattering behavior of quarks ts independent of their charge, or "flavour": Experiment 711 could test this assumption. Tilis dissertation descrtbes the analysis of the mass and angular distributions of hadron pair production for three separate charge states: +-, ++ and --. The angular distributions are found to deviate from theory predictions of flavour symmetry. Also. the mass cross sections indicate ratios of positive to negative hard-scattered particles that are larger than expected from theory. These results could warrant reconsideration of the assumptions and approximations currently made in leading-order QCD calculations.

  6. Angular glint effects generation for false naval target verisimility requirements

    International Nuclear Information System (INIS)

    Kostis, Theodoros G; Galanis, Konstantinos G; Katsikas, Sokratis K

    2009-01-01

    A stimulating problem in the generation of coherent countermeasures for high range resolution radar systems is the inclusion of angular glint effects in the preparation of the false target mask. Since angular glint is representative of extended naval targets, this inclusion increases the credibility factor of the decoy playback signal at the adversary radar-operator station. In this paper, the ability of an interferometric inverse synthetic aperture radar (InISAR) simulator to provide a proof of concept towards the clarification of this challenging task is ascertained. The solution consists of three novel vector representations of the generated data, which are proven to behave according to the laws of physics governing the glint phenomenon. The first depiction is the angular glint injection at the target which is followed by the representation of the wavefront distortion at the radar. A value-added time procession integration of the target in pure roll motion provides an expected by ISAR theory side-view image of the naval extended false target. The effectiveness of the proposed approach through verification and validation of the results by using the method of pictorial evidence is established. A final argument is raised on the usage of this software tool for actual obfuscation and deception actions for air defence at sea applications

  7. Philippine Astronomy Convention 2009 Abstract: Program Offerings in Astronomy in the Philippines

    Science.gov (United States)

    Torres, J. R. F.

    2009-03-01

    The formal academic programs in Astronomy of the Rizal Technological University are the first such programs in the Philippines. The Master of Science in Astronomy program is envisioned to provide the student with a wide range of knowledge in many areas of Astronomy, leaning towards the descriptive aspects of knowledge. The student will choose the field or research most suitable to his or her interests. Three of these researches done while enrolled in the program, and even researches completed before the student actually enrolled in the program, may be considered as his or her thesis. The program suits professionals in all persuasions who wish to study Astronomy either for professional advancement or plainly for the love of the science or for intellectual satisfaction. Non-science majors can enroll. In 2008, the RTU Graduate School decided to ladderize the MS program and the Graduate Diploma in Astronomy was designed. This program is suited for science educators, astronomy lecturers and entrepreneurs, members of astronomical societies, and plain astronomy enthusiasts who like to gain in-depth knowledge in the most important aspects of astronomy. A bachelor's degree in any field is required. The program can be finished in two semesters and one summer. If the student opts to continue in the MS in Astronomy program, all the courses he or she has earned in the Diploma will be credited. The Bachelor of Science in Astronomy Technology is an intensive baccalaureate degree program designed to prepare students to become future research scientists and technologists in the field of Astronomy. The BS in Astronomy Technology is a cross-fertilized program, integrating interrelated sciences, such as engineering, geology, remote sensing, physics, atmospheric and environmental science, biology and biochemistry, and even philosophy and entrepreneurship into the study. Thus, the B.S. in Astronomy Technology program gives the student excellent job opportunities in many fields.

  8. NASA Airborne Astronomy Ambassadors (AAA)

    Science.gov (United States)

    Backman, D. E.; Harman, P. K.; Clark, C.

    2016-12-01

    NASA's Airborne Astronomy Ambassadors (AAA) is a three-part professional development (PD) program for high school physics and astronomy teachers. The AAA experience consists of: (1) blended-learning professional development composed of webinars, asynchronous content learning, and a series of hands-on workshops (2) a STEM immersion experience at NASA Armstrong Flight Research Center's B703 science research aircraft facility in Palmdale, California, and (3) ongoing participation in the AAA community of practice (CoP) connecting participants with astrophysics and planetary science Subject Matter Experts (SMEs). The SETI Institute (SI) is partnering with school districts in Santa Clara and Los Angeles Counties during the AAA program's "incubation" period, calendar years 2016 through 2018. AAAs will be selected by the school districts based on criteria developed during spring 2016 focus group meetings led by the program's external evaluator, WestEd.. Teachers with 3+ years teaching experience who are assigned to teach at least 2 sections in any combination of the high school courses Physics (non-AP), Physics of the Universe (California integrated model), Astronomy, or Earth & Space Sciences are eligible. Partner districts will select at least 48 eligible applicants with SI oversight. WestEd will randomly assign selected AAAs to group A or group B. Group A will complete PD in January - June of 2017 and then participate in SOFIA science flights during fall 2017 (SOFIA Cycle 5). Group B will act as a control during the 2017-18 school year. Group B will then complete PD in January - June of 2018 and participate in SOFIA science flights in fall 2018 (Cycle 6). Under the current plan, opportunities for additional districts to seek AAA partnerships with SI will be offered in 2018 or 2019. A nominal two-week AAA curriculum component will be developed by SI for classroom delivery that will be aligned with selected California Draft Science Framework Disciplinary Core Ideas

  9. High Resolution Observations using Adaptive Optics: Achievements ...

    Indian Academy of Sciences (India)

    Hence, modern telescopes thrive on improving the spatial, spectral, and temporal resolutions using an AO system. It may be stated that most of the recent large solar. †NSO is operated by the Association of Universities for Research in Astronomy (AURA) under co-operative agreement with National Science Foundation ...

  10. Music and Astronomy Under the Stars

    Science.gov (United States)

    Lubowich, D.

    2008-11-01

    Bring telescope to where the people are! Music and Astronomy Under the Stars is a public astronomy outreach program at community parks during and after free summer music concerts and outdoor movie nights. This project also includes daytime activities because there are some afternoon concerts and daylight children's concerts, and observations using remotely operated telescopes in cloudy weather. While there have been many astronomy outreach activities and telescope observations at city sidewalks and parks, this program targets a completely different audience---music lovers who are attending free summer concerts held in community parks. The music lovers who may never have visited a science museum, planetarium, or star party will be exposed to telescope observations and astronomy information with no additional travel costs. This program will permit the entire community to participate in telescope observations and view astronomical video information to enhance the public appreciation of astronomy. This program will also reach underrepresented and underserved groups (women, minorities, older adults). The population base for the initial target audience (Nassau and Suffolk Counties, New York) is 2,500,000. My partners are the Amateur Observers' Society of New York (AOS) and the Towns of Oyster Bay, Hempstead, North Hempstead, and Huntington. Music and Astronomy Under the Stars is program that should continue beyond the International Year of Astronomy 2009 (IYA2009) and can be expanded into a national program.

  11. Interactive Materials In The Teaching Of Astronomy

    Science.gov (United States)

    Macêdo, J. A.; Voelzke, M. R.

    2014-10-01

    This study presents results of a survey conducted at the Federal Institution of Education, Science and Technology in the North of Minas Gerais (IFNMG), and aimed to investigate the potentialities of the use of interactive materials in the teaching of astronomy. An advanced training course with involved learning activities about basic concepts of astronomy was offered to thirty-two Licenciate students in Physics, Mathematics and Biological Science. The following steps were to be taken: i) analysis of the pedagogical projects (PPC) of the licenciates at the IFNMG, research locus of its Campus Januária; ii) analysis of students' preconceptions about astronomy and digital technologies, identified by the application of an initial questionnaire; iii) preparation of the course taking into account the students' previous knowledge; iv) application of the education proposal developed under part-time presence modality, using various interactive tools; v) application and analysis of the final questionnaire. The test was conducted with the qualitative and quantitative methodology, combined with a content analysis. The results indicated that in the IFNMG only the licenciate-course in physics includes astronomy content diluted in various subjects of the curriculum; the rates of students prior knowledge in relation to astronomy was low; an evidence of meaningful learning of the concepts related to astronomy, and of viability of resource use involving digital technologies in the Teaching of astronomy, which may contribute to the broadening of methodological options of future teachers and meet their training needs.

  12. A Brief History of Publishing Papers on Astronomy Education Research

    Science.gov (United States)

    Fraknoi, Andrew

    2014-01-01

    While some research had been done on K-12 and planetarium astronomy teaching from the 1930's to the 1980's, the growth of research on college physics education offered astronomy education researchers a model for examining techniques for teaching introductory college astronomy survey "Astronomy 101" courses as well. This early research…

  13. Women's and Men's Career Choices in Astronomy and Astrophysics

    Science.gov (United States)

    Ivie, Rachel; White, Susan; Chu, Raymond Y.

    2016-01-01

    The Longitudinal Study of Astronomy Graduate Students (LSAGS) arose from the 2003 Women in Astronomy Conference, where it was noted that a majority of young members of the American Astronomical Society were women. The astronomy community wishes to make every effort to retain young women in astronomy, so they commissioned a longitudinal study to be…

  14. Astronomy for teachers: A South African Perspective

    Science.gov (United States)

    de Witt, Aletha; West, Marion; Leeuw, Lerothodi; Gouws, Eldrie

    2015-08-01

    South Africa has nominated Astronomy as a “flagship science” and aims to be an international Astronomy hub through projects such as the Square Kilometre Array (SKA) and the South African Large Telescope (SALT). These projects open up career opportunities in maths, science and engineering and therefore offers a very real door for learners to enter into careers in science and technology through Astronomy. However, the Trends in International Mathematics and Science Survey (TIMSS), the Global Competitiveness Report (GCR) and Annual National Assessment (ANA) have highlighted that South Africa’s Science and Mathematics education is in a critical condition and that South African learners score amongst the worst in the world in both these subjects. In South Africa Astronomy is generally regarded as the worst taught and most avoided Natural Science knowledge strand, and most teachers that specialised in Natural Sciences, never covered Astronomy in their training.In order to address these issues a collaborative project between the University of South Africa (UNISA) and the Hartebeesthoek Radio Astronomy Observatory (HartRAO) was initiated, which aims to assist teachers to gain more knowledge and skills so that they can teach Astronomy with confidence. By collaborating we aim to ensure that the level of astronomy development will be raised in both South Africa and the rest of Africa.With the focus on Teaching and Learning, the research was conducted within a quantitative paradigm and 600 structured questionnaires were administered to Natural Science teachers in Public primary schools in Gauteng, South Africa. This paper reports the findings of this research and makes recommendations on how to assist teachers to teach Astronomy with confidence.

  15. Marine algae are `taught' the basics of angular momentum

    Science.gov (United States)

    Allen, John Taylor

    2017-11-01

    Advanced modelling studies and high-resolution observations have shown that flows related to instability of the mesoscale ( 1-10 km scale) may provide both the fertilisation mechanism for nutrient-depleted (oligotrophic) surface waters and a subduction mechanism for the rapid export of phytoplankton biomass to the deep ocean. Here, a detailed multidisciplinary analysis of the data from an example high-resolution observational campaign is presented. The data provide direct observations of the transport of phytoplankton through baroclinic instability. Furthermore, the data confirm that this transport is constrained by the requirement to conserve angular momentum, expressed in a stratified water column as the conservation of potential vorticity. This constraint is clearly seen to produce long thin filaments of phytoplankton populations strained out along isopycnal vorticity annuli associated with mesoscale frontal instabilities.

  16. Linear regression in astronomy. II

    Science.gov (United States)

    Feigelson, Eric D.; Babu, Gutti J.

    1992-01-01

    A wide variety of least-squares linear regression procedures used in observational astronomy, particularly investigations of the cosmic distance scale, are presented and discussed. The classes of linear models considered are (1) unweighted regression lines, with bootstrap and jackknife resampling; (2) regression solutions when measurement error, in one or both variables, dominates the scatter; (3) methods to apply a calibration line to new data; (4) truncated regression models, which apply to flux-limited data sets; and (5) censored regression models, which apply when nondetections are present. For the calibration problem we develop two new procedures: a formula for the intercept offset between two parallel data sets, which propagates slope errors from one regression to the other; and a generalization of the Working-Hotelling confidence bands to nonstandard least-squares lines. They can provide improved error analysis for Faber-Jackson, Tully-Fisher, and similar cosmic distance scale relations.

  17. Linear regression in astronomy. I

    Science.gov (United States)

    Isobe, Takashi; Feigelson, Eric D.; Akritas, Michael G.; Babu, Gutti Jogesh

    1990-01-01

    Five methods for obtaining linear regression fits to bivariate data with unknown or insignificant measurement errors are discussed: ordinary least-squares (OLS) regression of Y on X, OLS regression of X on Y, the bisector of the two OLS lines, orthogonal regression, and 'reduced major-axis' regression. These methods have been used by various researchers in observational astronomy, most importantly in cosmic distance scale applications. Formulas for calculating the slope and intercept coefficients and their uncertainties are given for all the methods, including a new general form of the OLS variance estimates. The accuracy of the formulas was confirmed using numerical simulations. The applicability of the procedures is discussed with respect to their mathematical properties, the nature of the astronomical data under consideration, and the scientific purpose of the regression. It is found that, for problems needing symmetrical treatment of the variables, the OLS bisector performs significantly better than orthogonal or reduced major-axis regression.

  18. Quantitative Activities for Introductory Astronomy

    Science.gov (United States)

    Keohane, Jonathan W.; Bartlett, J. L.; Foy, J. P.

    2010-01-01

    We present a collection of short lecture-tutorial (or homework) activities, designed to be both quantitative and accessible to the introductory astronomy student. Each of these involves interpreting some real data, solving a problem using ratios and proportionalities, and making a conclusion based on the calculation. Selected titles include: "The Mass of Neptune” "The Temperature on Titan” "Rocks in the Early Solar System” "Comets Hitting Planets” "Ages of Meteorites” "How Flat are Saturn's Rings?” "Tides of the Sun and Moon on the Earth” "The Gliese 581 Solar System"; "Buckets in the Rain” "How Hot, Bright and Big is Betelgeuse?” "Bombs and the Sun” "What Forms Stars?” "Lifetimes of Cars and Stars” "The Mass of the Milky” "How Old is the Universe?” "Is The Universe Speeding up or Slowing Down?"

  19. Gravitational waves and multimessenger astronomy

    Directory of Open Access Journals (Sweden)

    Ricci Fulvio

    2016-01-01

    Full Text Available It is widely expected that in the coming quinquennium the first gravitational wave signal will be directly detected. The ground-based advanced LIGO and Virgo detectors are being upgraded to a sensitivity level such that we expect to be measure a significant binary merger rate. Gravitational waves events are likely to be accompanied by electromagnetic counterparts and neutrino emission carrying complementary information to those associated to the gravitational signals. If it becomes possible to measure all these forms of radiation in concert, we will end up an impressive increase in the comprehension of the whole phenomenon. In the following we summarize the scientific outcome of the interferometric detectors in the past configuration. Then we focus on some of the potentialities of the advanced detectors once used in the new context of the multimessenger astronomy.

  20. Mac OS X for Astronomy

    Science.gov (United States)

    Pierfederici, F.; Pirzkal, N.; Hook, R. N.

    Mac OS X is the new Unix based version of the Macintosh operating system. It combines a high performance DisplayPDF user interface with a standard BSD UNIX subsystem and provides users with simultaneous access to a broad range of applications which were not previously available on a single system such as Microsoft Office and Adobe Photoshop, as well as legacy X11-based scientific tools and packages like IRAF, SuperMongo, MIDAS, etc. The combination of a modern GUI layered on top of a familiar UNIX environment paves the way for new, more flexible and powerful astronomical tools to be developed while assuring compatibility with already existing, older programs. In this paper, we outline the strengths of the Mac OS X platform in a scientific environment, astronomy in particular, and point to the numerous astronomical software packages available for this platform; most notably the Scisoft collection which we have compiled.

  1. Astronomy in the Digital Universe

    Science.gov (United States)

    Haisch, Bernard M.; Lindblom, J.; Terzian, Y.

    2006-12-01

    The Digital Universe is an Internet project whose mission is to provide free, accurate, unbiased information covering all aspects of human knowledge, and to inspire humans to learn, make use of, and expand this knowledge. It is planned to be a decades long effort, inspired by the Encyclopedia Galactica concept popularized by Carl Sagan, and is being developed by the non-profit Digital Universe Foundation. A worldwide network of experts is responsible for selecting content featured within the Digital Universe. The first publicly available content is the Encyclopedia of Earth, a Boston University project headed by Prof. Cutler Cleveland, which will be part of the Earth Portal. The second major content area will be an analogous Encyclopedia of the Cosmos to be part of the Cosmos Portal. It is anticipated that this will evolve into a major resource for astronomy education. Authors and topic editors are now being recruited for the Encyclopedia of the Cosmos.

  2. Academic Training: Astronomy from Space

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 14, 15, 16, 18 March from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 Astronomy from Space by T. Courvoisier / Observatoire de Genève In the very wide field of High Energy astrophysics we will select a number of topics that range from the source of radiative energy in the deep potential well around Schwarzschild and Kerr black holes and the basics of accretion disks around compact objects to the description and (where possible) the understanding of binary systems including a compact object (neutron star or black hole), of Active Galactic Nuclei and of gamma ray bursts. The approach that is chosen aims at giving an understanding of the most important phenomenologies encountered in high energy astrophysics rather than a detailed knowledge of one specific topic. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch

  3. Tides in astronomy and astrophysics

    CERN Document Server

    Mathis, Stéphane; Tokieda, Tadashi

    2013-01-01

    Based on the lecture notes of a school titled ‘Tides in Astronomy and Astrophysics’ that brought together students and researchers, this book focuses on the fundamental theories of tides at different scales of the universe—from tiny satellites to whole galaxies—and on the most recent developments. It also attempts to place the study of tides in a historical perspective. Starting with a general tutorial on tides, the theme of tides is approached in 9 chapters from many directions. They allow non-experts to pick up a physical intuition and a sense of orders of magnitude in the theory of tides. These carefully prepared lecture notes by leaders in the field include many illustrative figures and drawings. Some even offer a variety of simple back-of the-envelope problems.

  4. A Website for Astronomy Education and Outreach

    Science.gov (United States)

    Impey, C.; Danehy, A.

    2017-09-01

    Teach Astronomy is a free, open access website designed for formal and informal learners of astronomy. The site features: an online textbook complete with quiz questions and a glossary; over ten thousand images; a curated collection of the astronomy articles in Wikipedia; a complete video lecture course; a video Frequently Asked Questions tool; and other materials provided by content partners. Clustering algorithms and an interactive visual interface allow users to browse related content. This article reviews the features of the website and how it can be used.

  5. Advances in astronomy and astrophysics 9

    CERN Document Server

    Kopal, Zdenek

    1972-01-01

    Advances in Astronomy and Astrophysics, Volume 9 covers reviews on the advances in astronomy and astrophysics. The book presents reviews on the Roche model and its applications to close binary systems. The text then describes the part played by lunar eclipses in the evolution of astronomy; the classical theory of lunar eclipses; deviations from geometrical theory; and the methods of photometric observations of eclipses. The problems of other phenomena related in one way or another to lunar eclipses are also considered. The book further tackles the infrared observation on the eclipsed moon, as

  6. Executive Committee Working Group Women in Astronomy

    Science.gov (United States)

    Maddison, Sarah; Primas, Francesca; Aerts, Conny; Clayton, Geoffery; Combes, Françoise; Dubner, Gloria; Feretti, Luigina; Green, Anne; Griffin, Elizabeth; Liang, Yanchun; Motizuki, Yuko; Nordström, Birgitta

    2012-04-01

    The Working Group was created at the 25th IAU General Assembly in Sydney, Australia, in July 2003 by the IAU Executive Council as a Working Group of IAU Executive. The aims of the Working Group are to evaluate the status of women in astronomy through the collection of statistics over all countries where astronomy research is carried out; and to establish strategies and actions that can help women to attain true equality as research astronomers, which will add enormous value to all of astronomy.

  7. Reflections on the astronomy of Glasgow

    CERN Document Server

    Clarke, David

    2013-01-01

    How Astronomy contributed to the educational enlightenment of Glasgow, to its society and to its commerce. The words 'Astronomy' and 'Glasgow' seem an incongruous juxtaposition, and yet the two are closely linked over 500 years of history. This is a tale of enlightenment and scientific progress at both institutional and public levels. Combined with the ambitions of civic commerce, it is a story populated with noteworthy personalities and intense rivalries.It is remarkable to realise that the first Astronomy teaching in the Glasgow 'Colledge' presented an Earth-centred Universe, prior to the Co

  8. Optical communication beyond orbital angular momentum

    CSIR Research Space (South Africa)

    Trichili, A

    2016-06-01

    Full Text Available Mode division multiplexing (MDM) is mooted as a technology to address future bandwidth issues, and has been successfully demonstrated in free space using spatial modes with orbital angular momentum (OAM). To further increase the data transmission...

  9. Dynamical Model of Fission Fragment Angular Distribution

    Science.gov (United States)

    Drozdov, V. A.; Eremenko, D. O.; Fotina, O. V.; Platonov, S. Yu.; Yuminov, O. A.; Giardina, G.; Taccone, A.

    2002-01-01

    A dynamical model of fission fragment angular distributions is suggested. The model allows one to calculate fission fragment angular distributions, prescission light particle multyplicities, evaporation residue cross sections etc. for the cases of decay of hot and rotating heavy nuclei. The experimental data on angular anisotropies of fission fragments and prescission neutron multiplicities are analyzed for the 16O + 208Pb, 232Th, 248Cm and 238U reactions at the energies of the incident 16O ions ranging from 90 to 160 MeV. This analysis allows us to extract both the nuclear friction coefficient value and the relaxation time for the tilting mode. It is also demonstrated that the angular distributions are sensitive to the deformation dependence of the nuclear friction.

  10. Amplitude damping channel for orbital angular momentum

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2010-03-01

    Full Text Available Since the pioneering work on the entanglement of the orbital angular momentum (OAM) states of light, much attention has been devoted to the subject, with particular attention into the quantum aspects of information processing using OAM. Furthermore...

  11. Mastering AngularJD for .NET developers

    CERN Document Server

    Majid, Mohammad Wadood

    2015-01-01

    This book is envisioned for traditional developers and programmers who want to develop client-side applications using the AngularJS framework and ASP.NET Web API 2 with Visual Studio. .NET developers who have already built web applications or web services and who have a fundamental knowledge of HTML, JavaScript, and CSS and want to explore single-page applications will also find this guide useful. Basic knowledge of AngularJS would be helpful.

  12. Binary asteroid population. 1. Angular momentum content

    Czech Academy of Sciences Publication Activity Database

    Pravec, Petr; Harris, A. W.

    2007-01-01

    Roč. 190, č. 1 (2007), s. 250-259 ISSN 0019-1035 R&D Projects: GA ČR(CZ) GA205/05/0604 Institutional research plan: CEZ:AV0Z10030501 Keywords : asteroids * satellites of asteroids Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.869, year: 2007

  13. Partial angular coherence and the angular Schmidt spectrum of entangled two-photon fields

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Anand Kumar; Boyd, Robert W. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Agarwal, Girish S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

    2011-12-15

    We study partially coherent fields that have a coherent-mode representation in the orbital-angular-momentum-mode basis. For such fields, we introduce the concepts of the angular coherence function and the coherence angle. Such fields are naturally produced by the process of parametric down-conversion--a second-order nonlinear optical process in which a pump photon breaks up into two entangled photons, known as the signal and idler photons. We show that the angular coherence functions of the signal and idler fields are directly related to the angular Schmidt (spiral) spectrum of the down-converted two-photon field and thus that the angular Schmidt spectrum can be measured directly by measuring the angular coherence function of either the signal or the idler field, without requiring coincidence detection.

  14. NAOJ's activities on Astronomy for Development: Aiding Astronomy Education in Developing Nations

    Science.gov (United States)

    Sekiguchi, K.; Yoshida, F.

    2015-03-01

    We summarize NAOJ's efforts to promote astronomy in developing nations. The Office of International Relations, collaborations with the Office of Public Outreach at NAOJ and with the East Asia Core Observatories Association (EACOA), has engaged children, students and educators about astronomy development in the Asia-Pacific region. In particular, we introduce ``You are Galileo!`` project, which is a very well received astronomy education program for children. We also report on a continuing effort by the Japanese Government in support of astronomy programs in the developing nations.

  15. ORGANIZATIONS AND STRATEGIES IN ASTRONOMY VOLUME 7

    CERN Document Server

    HECK, ANDRÉ

    2006-01-01

    This book is the seventh volume under the title Organizations and Strategies in Astronomy (OSA). The OSA series covers a large range of fields and themes: in practice, one could say that all aspects of astronomy-related life and environment are considered in the spirit of sharing specific expertise and lessons learned. The chapters of this book are dealing with socio-dynamical aspects of the astronomy (and related space sciences) community: characteristics of organizations, strategies for development, operational techniques, observing practicalities, journal and magazine profiles, public outreach, publication studies, relationships with the media, research communication, series of conferences, evaluation and selection procedures, research indicators, national specificities, contemporary history, and so on. The experts contributing to this volume have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy while providing specific detailed information and somet...

  16. John Quincy Adams's rhetorical crusade for astronomy.

    Science.gov (United States)

    Portolano, M

    2000-09-01

    Astronomy thrived in Europe during the early nineteenth century, but in the United States a utilitarian mind-set opposed it. John Quincy Adams's oratory in support of American astronomical discovery reached its peak during congressional debate over the Smithsonian Institution (1838-1846). During this debate Adams countered proposals to found a university with plans for an observatory. His addresses to congressional and public audiences about observatories and astronomy were intended to foster interest in the science and encourage the growing astronomical community in America. Although the U.S. Naval Observatory in Washington, D.C., was established before the Smithsonian debate ended, many considered Adams its political father. Adams composed his speeches on astronomy in a systematic manner, following neoclassical principles of rhetoric that he had taught at Harvard University. His speeches both in and outside of Congress show evidence of the rhetorical principles he conscientiously used in the service of astronomy.

  17. The Past and Future of American Astronomy

    Science.gov (United States)

    Sagan, Carl

    1974-01-01

    Traces the history of astronomy by analyzing the scientific literature of various time periods, reviewing prize-winning research, and noting the input from physics. Speculates on some accomplishments that may occur in the next 75 years. (GS)

  18. Making Space for Specialized Astronomy Resources

    Science.gov (United States)

    MacMillan, D.

    2007-10-01

    With the growth of both free and subscription-based resources, articles on astronomy have never been easier to find. Locating the best and most current materials for any given search, however, now requires multiple tools and strategies dependent on the query. An analysis of the tools currently available shows that while astronomy is well-served by Google Scholar, Scopus and Inspec, its literature is best accessed through specialized resources such as ADS (Astrophysics Data System). While no surprise to astronomers, this has major implications for those of us who teach information literacy skills to astronomy students and work in academic settings where astronomy is just one of many subjects for which our non-specialist colleagues at the reference desk provide assistance. This paper will examine some of the implications of this analysis for library instruction, reference assistance and training, and library webpage development.

  19. Learning Exercises in Astronomy for Elementary Students

    Science.gov (United States)

    Jacoby, Suzanne H.

    1995-12-01

    Astronomers from the Tucson based National Optical Astronomy Observatories and students in grades K-3 at the Satori School are learning from each other about astronomy and science education. This project is partially funded by a NASA IDEA Grant (Initiative to Develop Education through Astronomy). NOAO astronomers are working with the students and teachers over a series of 12 weeks to present basic concepts in planetary and solar astronomy. Each presentation includes a discussion with the astronomers and a hands-on active learning exercise. Topics presented include: The Living Solar System, Impacts and Hazards, Comets, Space Resources, The Natural Sun, The Sun as a Clock, Sunspots and Solar Rotation, and Solar Music - Helioseismology. Lessons learned, by students and astronomers, will be presented and printed lesson modules available for distribution.

  20. SOFIA - Stratospheric Observatory for Infrared Astronomy

    Science.gov (United States)

    Kunz, Nans; Bowers, Al

    2007-01-01

    This viewgraph presentation reviews the Stratospheric Observatory for Infrared Astronomy (SOFIA). The contents include: 1) Heritage & History; 2) Level 1 Requirements; 3) Top Level Overview of the Observatory; 4) Development Challenges; and 5) Highlight Photos.

  1. SOFIA: Stratospheric Observatory for Infrared Astronomy

    Science.gov (United States)

    Becker, Eric; Kunz, Nans; Bowers, Al

    2007-01-01

    This viewgraph presentation reviews the Stratospheric Observatory for Infrared Astronomy (SOFIA). The contents include: 1) Heritage & History; 2) Level 1 Requirements; 3) Top Level Overview of the Observatory; 4) Development Challenges; and 5) Highlight Photos.

  2. Extragalactic astronomy and cosmology an introduction

    CERN Document Server

    Schneider, Peter

    2015-01-01

    Accounting for the astonishing developments in the field of Extragalactic Astronomy and Cosmology, this second edition has been updated and substantially expanded. Starting with the description of our home galaxy, the Milky Way, this cogently written textbook introduces the reader to the astronomy of galaxies, their structure, active galactic nuclei, evolution and large scale distribution in the Universe. After an extensive and thorough introduction to modern observational and theoretical cosmology, the focus turns to the formation of structures and astronomical objects in the early Universe. The basics of classical astronomy and stellar astrophysics needed for extragalactic astronomy are provided in the appendix. The new edition incorporates some of the most spectacular results from new observatories like the Galaxy Evolution Explorer, Herschel, ALMA, WMAP and Planck, as well as new instruments and multi-wavelength campaigns which have expanded our understanding of the Universe and the objects populating it....

  3. Organizations and Strategies in Astronomy Volume 6

    CERN Document Server

    Heck, André

    2006-01-01

    This book is the sixth volume under the title Organizations and Strategies in Astronomy (OSA). The OSA series is intended to cover a large range of fields and themes. In practice, one could say that all aspects of astronomy-related life and environment are considered in the spirit of sharing specific expertise and lessons learned. The chapters of this book are dealing with socio-dynamical aspects of the astronomy (and related space sciences) community: characteristics of organizations, strategies for development, legal issues, operational techniques, observing practicalities, educational policies, journal and magazine profiles, public outreach, publication studies, relationships with the media, research communication, evaluation and selection procedures, research indicators, national specificities, contemporary history, and so on. The experts contributing to this volume have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy while providing specific detai...

  4. Handbook of X-Ray Astronomy

    Science.gov (United States)

    Arnaud, Keith A. (Editor); Smith, Randall K.; Siemiginowska, Aneta

    2011-01-01

    X-ray astronomy was born in the aftermath of World War II as military rockets were repurposed to lift radiation detectors above the atmosphere for a few minutes at a time. These early flights detected and studied X-ray emission from the Solar corona. The first sources beyond the Solar System were detected during a rocket flight in 1962 by a team headed by Riccardo Giaccom at American Science and Engineering, a company founded by physicists from MIT. The rocket used Geiger counters with a system designed to reduce non-X-ray backgrounds and collimators limiting the region of sky seen by the counters. As the rocket spun, the field of view (FOV) happened to pass over what was later found to be the brightest non-Solar X-ray source; later designated See X-1. It also detected a uniform background glow which could not be resolved into individual sources. A follow-up campaign using X-ray detectors with better spatial resolution and optical telescopes identified See X-1 as an interacting binary with a compact (neutron star) primary. This success led to further suborbital rocket flights by a number of groups. More X-ray binaries were discovered, as well as X-ray emission from supernova remnants, the radio galaxies M87 and Cygnus-A, and the Coma cluster. Detectors were improved and Geiger counters were replaced by proportional counters, which provided information about energy spectra of the sources. A constant challenge was determining precise positions of sources as only collimators were available.

  5. 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/).

  6. Developing technologies for lunar-based astronomy

    Science.gov (United States)

    Johnson, Stewart W.; Burns, Jack O.; Chua, Koon Meng; Wetzel, John P.

    1992-01-01

    Prospects for lunar-based astronomy and the development of the required technologies are briefly reviewed. A systematic approach to lunar-based astronomy includes a progression in capability from small automated telescopes to the 16-meter reflector on the moon. A next step beyond the 16-meter reflector will be a Lunar Optical/Ultraviolet/Infrared Synthesis Array. Intermediate steps are represented by the Lunar Transit Telescope and the Lunar Cluster Telescope Experiment. Priorities for the required technology development are identified.

  7. Astronomy for the Blind and Visually Impaired

    Science.gov (United States)

    Kraus, S.

    2016-12-01

    This article presents a number of ways of communicating astronomy topics, ranging from classical astronomy to modern astrophysics, to the blind and visually impaired. A major aim of these projects is to provide access which goes beyond the use of the tactile sense to improve knowledge transfer for blind and visually impaired students. The models presented here are especially suitable for young people of secondary school age.

  8. Astronomy Over the Former Soviet Territory: 15 Years after the USSR Disintegration

    Science.gov (United States)

    Bochkarev, N. G.

    2006-08-01

    During the post-Soviet period, the main infrastructure of astronomy over the territory of FSU was kept saved, in spite of dramatic decreasing of financial support. The overall situation in FSU astronomy is stable. In Latvia, the 32-m radio-dish is put into working order that allows it's joining VLBI programs and handed over to the Venspils University. In Russia, all the three 32-meter radio dishes of the QUASAR VLBI system are put in operation, as well as the 2-m telescope with a high-resolution spectrograph (up to resolution R≈500000) and the horizontal solar telescope (R= 320000) of the Russian-Ukrainian Observatory on Peak Terskol (Caucasus, altitude 3100 m). But the situation with the observatory is worrying, because of the regional authorities attempt to privatize its infrastructure. The process of equipping a number of CIS (including Russian) observatories with CCD-cameras is in progress. To solve the staff problems Kazakhstan, Tajikistan and Uzbekistan have begun to prepare national specialists in astronomy and Baltic States, Armenia, Azerbaijan, Georgia, Russia, Ukraine continue to prepare astronomers. Teaching of astronomy at schools is obligatory in Ukraine and Baltic Countries only. To maintain a "common astronomical space" Eurasian Astronomical Society (EAAS) continues the program of reduced-price subscription to Russian-language astronomical journals and magazines over the territory of FSU, organization of international conferences and Olympiads for school students, lectures for school teachers and planetarium lecturers, etc.

  9. On the angular distribution of X rays of multiply ionized atoms

    International Nuclear Information System (INIS)

    Papp, T.

    1999-01-01

    The angular distributions of X-rays emitted by transitions between aligned initial and aligned final states have been studied. Angular distribution formulas for these transitions are derived for the cases when polarization insensitive or polarization sensitive detection techniques are used. Large anisotropies are expected for multiply ionized atoms, and it was obtained that the unresolved satellites may have considerable anisotrophy. The alignment of both the initial and final states is calculated for double L and M shell ionization in the framework of the semi-classical approximation (SCA). When the lower energy level has spherical symmetry, the upper state alignment can cause anisotropic angular distributions for the unresolved satellites. Angular distribution measurements were carried out for the Kα and Kβ transitions of nickel ionized by hydrogen and helium ion impacts. Anisotropic angular distribution was found for the Kα/Kβ intensity ratio. Double ionization probabilities were derived from the angular distribution and were found to be in good agreement with the high resolution data on satellite intensities of the same collision system

  10. An angular multigrid method for computing mono-energetic particle beams in Flatland

    Science.gov (United States)

    Börgers, Christoph; MacLachlan, Scott

    2010-04-01

    Beams of microscopic particles penetrating scattering background matter play an important role in several applications. The parameter choices made here are motivated by the problem of electron-beam cancer therapy planning. Mathematically, a steady particle beam penetrating matter, or a configuration of several such beams, is modeled by a boundary value problem for a Boltzmann equation. Grid-based discretization of such a problem leads to a system of algebraic equations. This system is typically very large because of the large number of independent variables in the Boltzmann equation—six if no dimension-reducing assumptions other than time independence are made. If grid-based methods are to be practical for these problems, it is therefore necessary to develop very fast solvers for the discretized problems. For beams of mono-energetic particles interacting with a passive background, but not with each other, in two space dimensions, the first author proposed such a solver, based on angular domain decomposition, some time ago. Here, we propose and test an angular multigrid algorithm for the same model problem. Our numerical experiments show rapid, grid-independent convergence. For high-resolution calculations, our method is substantially more efficient than the angular domain decomposition method. In addition, unlike angular domain decomposition, the angular multigrid method works well even when the angular diffusion coefficient is fairly large.

  11. Future Professional Communication in Astronomy II

    Science.gov (United States)

    Accomazzi, Alberto

    The present volume gathers together the talks presented at the second colloquium on the Future Professional Communication in Astronomy (FPCAII), held at the Harvard-Smithsonian Center for Astrophysics (Cambridge, MA) on 13-14 April 2010. This meeting provided a forum for editors, publishers, scientists, librarians and officers of learned societies to discuss the future of the field. The program included talks from leading researchers and practitioners and drew a crowd of approximately 50 attendees from 10 countries. These proceedings contain contributions from invited and contributed talks from leaders in the field, touching on a number of topics. Among them: The role of disciplinary repositories such as ADS and arXiv in astronomy and the physical sciences; Current status and future of Open Access Publishing models and their impact on astronomy and astrophysics publishing; Emerging trends in scientific article publishing: semantic annotations, multimedia content, links to data products hosted by astrophysics archives; Novel approaches to the evaluation of facilities and projects based on bibliometric indicators; Impact of Government mandates, Privacy laws, and Intellectual Property Rights on the evolving digital publishing environment in astronomy; Communicating astronomy to the public: the experience of the International Year of Astronomy 2009.

  12. Methodological pluralism in the teaching of Astronomy

    Science.gov (United States)

    de Macedo, Josué Antunes; Voelzke, Marcos Rincon

    2015-04-01

    This paper discusses the feasibility of using a teaching strategy called methodological pluralism, consisting of the use of various methodological resources in order to provide a meaningful learning. It is part of a doctoral thesis, which aims to investigate contributions to the use of traditional resources combined with digital technologies, in order to create autonomy for future teachers of Natural Sciences and Mathematics in relation to themes in Astronomy. It was offered an extension course at the "Federal Institution of Education, Science and Technology" in the North of Minas Gerais (FINMG), Campus Januaria, for thirty-two students of licentiate courses in Physics, Mathematics and Biological Sciences, involving themes of Astronomy, in order to search and contribute to improving the training of future teachers. The following aspects are used: the mixed methodology, with pre-experimental design, combined with content analysis. The results indicate the rates of students' prior knowledge in relation to Astronomy was low; meaningful learning indications of concepts related to Astronomy, and the feasibility of using digital resources Involving technologies, articulated with traditional materials in the teaching of Astronomy. This research sought to contribute to the initial teacher training, especially in relation to Astronomy Teaching, proposing new alternatives to promote the teaching of this area of knowledge, extending the methodological options of future teachers.

  13. Astronomy in Hawaii: Telescopes, Research, and Libraries

    Science.gov (United States)

    Robertson, A. K.

    2012-08-01

    Since early Polynesian way-finding combined observations of sky and ocean and allowed voyagers to locate and se ttle the far-flung islands of the Pacific, astronomy has impacted the islands of Hawaii. The Twentieth Century saw telescope development on both Haleakala on Maui and Mauna Kea on Hawaii Island. These complexes have developed libraries and information services to support and enhance their research. The University of Hawaii established the Institute for Astronomy (IfA). The IfA Library serves researchers and instrument developers at each of its three locations. Canada-France-Ha waii Telescope, the Joint Astronomy Center, the W. M. Keck Observatory, Gemini Northern Telescope and Subaru Telescope have each developed library services to respond to their unique needs. The librarians at these organizations have formed Astronomy Libraries of HAwaii (A LOHA) to share resources. As electronic research has developed, each library has responded to capitalize on these new capabilities. In coming years, projects such as the Advanced Technology Solar Telescope on Maui and the Thirty Meter Telescope on Hawaii Island have the promise of enlarging our understanding of the Universe. Astronomy libraries in Hawaii will con tinue to enhance their expertise to match the evolution of astronomy technologies and maximize research impact.

  14. Improving Teach Astronomy: A Survey of Instructors

    Science.gov (United States)

    Wenger, Matthew; Riabokin, Malanka; Impey, Chris David

    2018-01-01

    Teach Astronomy is a website that provides educational resources for introductory astronomy. The motivation behind constructing this site was to provide quality online educational tools for use as a primary or supplementary instructional resource for teachers and students. The website provides an online textbook, glossary, podcasts and video summaries of concepts. As the popularity of online courses steadily increases, so does the demand for robust online educational resources. In order to cater to our users, our team conducted a survey of the instructors that use Teach Astronomy site for feedback for use in updating and streamlining the website content. The survey collected feedback regarding functionality of each of the website tools, in which courses the site was being used, and the motivation of the instructors use of our site. The overwhelming majority of responses indicate that instructors use the website as a class textbook in introductory astronomy courses for non-science majors, and instructors also generally tended to agree that the site content was comprehensive and lucid. One interesting result of the survey is to cluster topics in a way that is consistent with different levels of instruction (i.e. grouping middle-school level content and university level content distinctly). Our team will use this feedback to improve the Teach Astronomy website and maintain it as a high-quality, free online resource. We will also continue to gather feedback from instructors to ensure that the Teach Astronomy website stays current and remains a valuable online resource for instructors around the country.

  15. Affordable and lightweight high-resolution x-ray optics for astronomical missions

    Science.gov (United States)

    Zhang, W. W.; Biskach, M. P.; Bly, V. T.; Carter, J. M.; Chan, K. W.; Gaskin, J. A.; Hong, M.; Hohl, B. R.; Jones, W. D.; Kolodziejczak, J. J.; Kolos, L. D.; Mazzarella, J. R.; McClelland, R. S.; McKeon, K. P.; Miller, T. M.; O'Dell, S. L.; Riveros, R. E.; Saha, T. T.; Schofield, M. J.; Sharpe, M. V.; Smith, H. C.

    2014-07-01

    Future x-ray astronomical missions require x-ray mirror assemblies that provide both high angular resolution and large photon collecting area. In addition, as x-ray astronomy undertakes more sensitive sky surveys, a large field of view is becoming increasingly important as well. Since implementation of these requirements must be carried out in broad political and economical contexts, any technology that meets these performance requirements must also be financially affordable and can be implemented on a reasonable schedule. In this paper we report on progress of an x-ray optics development program that has been designed to address all of these requirements. The program adopts the segmented optical design, thereby is capable of making both small and large mirror assemblies for missions of any size. This program has five technical elements: (1) fabrication of mirror substrates, (2) coating, (3) alignment, (4) bonding, and (5) mirror module systems engineering and testing. In the past year we have made progress in each of these five areas, advancing the angular resolution of mirror modules from 10.8 arc-seconds half-power diameter reported (HPD) a year ago to 8.3 arc-seconds now. These mirror modules have been subjected to and passed all environmental tests, including vibration, acoustic, and thermal vacuum. As such this technology is ready for implementing a mission that requires a 10-arc-second mirror assembly. Further development in the next two years would make it ready for a mission requiring a 5-arc-second mirror assembly. We expect that, by the end of this decade, this technology would enable the x-ray astrophysical community to compete effectively for a major x-ray mission in the 2020s that would require one or more 1-arc-second mirror assemblies for imaging, spectroscopic, timing, and survey studies.

  16. Atelier d'astronomie X

    Science.gov (United States)

    Ballet, J.; Barret, D.

    2001-01-01

    L'astronomie X connait aujourd'hui une de ses périodes les plus actives et les plus fastes, après le lancement de Chandra et XMM-Newton, et alors que Beppo SAX et Rossi XTE sont toujours en orbite. L'extraordinaire complémentarité de ces satellites est telle que leur domaine d'utilisation est extrêmement vaste, couvrant des étoiles jeunes aux toujours énigmatiques sursauts γ, en passant bien entendu par les trous noirs accrétants dans les binaires X ou dans les noyaux actifs de galaxies. L'atelier fut organisé selon quatre thèmes les étoiles, les phénomènes explosifs, les binaires X et les noyaux actifs de galaxies. Les résultats qui y furent présentés, pour chacun de ces thèmes témoignent de la superbe qualité des données obtenues. En particulier l'accès à la haute résolution spectrale (réseaux) en rayons X marque un pas important. Les présentations plus théoriques ont montré que parallèlement des progrès significatifs sont réalisés dans la physique de l'accrétion autour des objets compacts. Les actes de l'atelier donnent un panorama représentatif des progrès réalisés récemment par l'astronomie X, aussi bien du point de vue observationnel que théorique. Ces actes de colloque sont aussi l'occasion de rappeler l'historique et ce que furent les activités scientifiques de notre GdR au moment ou il doit s'intègrer au GdR PCHE et au PNPS. Enfin, pour toutes informations complémentaires concernant l'atelier: http://www.cesr.fr/~barret/adj/vg.html Ce site donne accès en particulier à la plupart des présentations (transparents).

  17. High resolution backscattering instruments

    International Nuclear Information System (INIS)

    Coldea, R.

    2001-01-01

    The principle of operation of indirect-geometry time-of-flight spectrometers are presented, including the IRIS at the ISIS spallation neutron source. The key features that make those types of spectrometers ideally suited for low-energy spectroscopy are: high energy resolution over a wide dynamic range, and simultaneous measurement over a large momentum transfer range provided by the wide angular detector coverage. To exemplify these features are discussed of single-crystal experiments of the spin dynamics in the two-dimensional frustrated quantum magnet Cs 2 CuCl 4 . (R.P.)

  18. Launching Astronomy: Standards and STEM Integration (LASSI)

    Science.gov (United States)

    French, Debbie; Burrows, Andrea C.; Myers, Adam D.

    2015-01-01

    While astronomy is prevalent in the Next Generation Science Standards, it is often relegated to the '4th nine-weeks' in middle and high school curricula. I.e., it is taught at the end of the year, if time permits. However, astronomy ties in many core ideas from chemistry, earth science, physics, and even biology (with astrobiology being an up-and-coming specialization) and mathematics. Recent missions to Mars have captured students' attention and have added excitement to the fields of engineering and technology. Using astronomy as a vehicle to teach science, technology, engineering, and mathematics (STEM) connects these disciplines in an engaging way. The workshop entitled, 'Launching Astronomy: Standards and STEM Integration,' (LASSI) is a year-long professional development (PD) opportunity for teachers in grades K-12 to use astronomy as a vehicle to teach STEM and implement science standards through astronomy. Eight teachers participated in a two-week summer workshop and six follow-up sessions are scheduled during the 2014-2015 school year. Additional teachers plan to participate in the upcoming follow-up sessions. We evaluate the effectiveness of the LASSI PD to identify and confront teachers' misconceptions in astronomy, and discuss whether teachers identified topics for which astronomy can be used as a vehicle for standards-based STEM curricula. Teachers from around Wyoming were invited to participate. Participating teachers were surveyed on the quality of the workshop, their astronomy content knowledge before and after listening to talks given by experts in the field, conducting standards-based inquiry activities, developing their own lessons, and their level of engagement throughout the workshop. Two-thirds of teachers planned to incorporate LASSI activities into their classrooms in this school year. Teachers' misconceptions and requests for astronomy-based curriculum were identified in the summer session. These will be addressed during the follow-up session

  19. Astronomy TV outreach, CUBA experiences

    Science.gov (United States)

    Alvarez, Oscar

    2015-08-01

    As professional astronomer and science communicator, I want to share my personal experience communicating Astronomy and general science principles in maybe, the most popular science outreach devoted TV program in Cuba. It is broadcasted nationwide in a prime time schedule every Sunday. The Science Popularization on TV, is in a Third World Country hard to do if you want to produce attractive materials for a broad audience. Budgets constraints in most of the cases and lack of the technical equipment required to produce first class visual materials conspire, against motivation and creativity of local scientists and media professionals. A way to show the advance of the national scientific community in Science fields and connecting them in a friendly relation with a broad majority of the people, is to combine the wisdom and knowledge of the local scientists together with the most spectacular TV production of the first world countries. Commenting, analyzing and conveying the hard science into the public debate of the common citizens. Here is shown a way to convey cutting edge science to the general public, using limited resources to produce imaginative television productions, highlighting the development, knowledge and wisdom of the local scientists.

  20. Industrial interference and radio astronomy

    Science.gov (United States)

    Jessner, A.

    2013-07-01

    The interferer - victim scenario is described for the case of industrial interference affecting radio astronomical observatories. The sensitivity of radio astronomical receivers and their interference limits are outlined. EMC above 30 MHz is a serious problem for Radio Astronomy. Interferer (CISPR) and victim (ITU-R RA 769) standards are not harmonised. The emissions from the interferer and their spectral characteristics are not defined sufficiently well by CISPR standards. The required minimum coupling losses (MCL) between an industrial device and radio astronomical antenna depends on device properties but is shown to exceed 140 dB in most cases. Spatial separation of a few km is insufficient on its own, the terrain must shield > 30-40 dB, additional mitigations such as extra shielding or suppression of high frequency emissions may be necessary. A case by case compatibility analysis and tailored EMC measures are required for individual installations. Aggregation of many weak rfi emitters can become serious problem. If deployment densities are high enough, the emission constraints can even exceed those for a single interferer at a short distance from the radio observatory. Compatibility studies must account not only for the single interferer but also for many widely distributed interference sources.

  1. Astronomy Learning Activities for Tablets

    Science.gov (United States)

    Pilachowski, Catherine A.; Morris, Frank

    2015-08-01

    Four web-based tools allow students to manipulate astronomical data to learn concepts in astronomy. The tools are HTML5, CSS3, Javascript-based applications that provide access to the content on iPad and Android tablets. The first tool “Three Color” allows students to combine monochrome astronomical images taken through different color filters or in different wavelength regions into a single color image. The second tool “Star Clusters” allows students to compare images of stars in clusters with a pre-defined template of colors and sizes in order to produce color-magnitude diagrams to determine cluster ages. The third tool adapts Travis Rector’s “NovaSearch” to allow students to examine images of the central regions of the Andromeda Galaxy to find novae. After students find a nova, they are able to measure the time over which the nova fades away. A fourth tool, Proper Pair, allows students to interact with Hipparcos data to evaluate close double stars are physical binaries or chance superpositions. Further information and access to these web-based tools are available at www.astro.indiana.edu/ala/.

  2. Astronomy Fun with Mobile Devices

    Science.gov (United States)

    Pilachowski, Catherine A.; Morris, Frank

    2016-01-01

    Those mobile devices your students bring to class can do more that tweet and text. Engage your students with these web-based astronomy learning tools that allow students to manipulate astronomical data to learn important concepts. The tools are HTML5, CSS3, Javascript-based applications that provide access to the content on iPad and Android tablets. With "Three Color" students can combine monochrome astronomical images taken through different color filters or in different wavelength regions into a single color image. "Star Clusters" allows students to compare images of clusters with a pre-defined template of colors and sizes to compare clusters of different ages. An adaptation of Travis Rector's "NovaSearch" allows students to examine images of the central regions of the Andromeda Galaxy to find novae and to measure the time over which the nova fades away. New additions to our suite of applications allow students to estimate the surface temperatures of exoplanets and the probability of life elsewhere in the Universe. Further information and access to these web-based tools are available at www.astro.indiana.edu/ala/.

  3. Space Debris and Observational Astronomy

    Science.gov (United States)

    Seitzer, Patrick

    2018-01-01

    Since the launch of Sputnik 1 in 1957, astronomers have faced an increasing number of artificial objects contaminating their images of the night sky. Currently almost 17000 objects larger than 10 cm are tracked and have current orbits in the public catalog. Active missions are only a small fraction of these objects. Most are inactive satellites, rocket bodies, and fragments of larger objects: all space debris. Several mega-constellations are planned which will increase this number by 20% or more in low Earth orbit (LEO). In terms of observational astronomy, this population of Earth orbiting objects has three implications: 1) the number of streaks and glints from spacecraft will only increase. There are some practical steps that can be taken to minimize the number of such streaks and glints in astronomical imaging data. 2) The risk to damage to orbiting astronomical telescopes will only increase, particularly those in LEO. 3) If you are working on a plan for an orbiting telescope project, then there are specific steps that must be taken to minimize space debris generation during the mission lifetime, and actions to safely dispose of the spacecraft at end of mission to prevent it from becoming space debris and a risk to other missions. These steps may involve sacrifices to mission performance and lifetime, but are essential in today's orbital environment.

  4. Transverse angular momentum in topological photonic crystals

    Science.gov (United States)

    Deng, Wei-Min; Chen, Xiao-Dong; Zhao, Fu-Li; Dong, Jian-Wen

    2018-01-01

    Engineering local angular momentum of structured light fields in real space enables applications in many fields, in particular, the realization of unidirectional robust transport in topological photonic crystals with a non-trivial Berry vortex in momentum space. Here, we show transverse angular momentum modes in silicon topological photonic crystals when considering transverse electric polarization. Excited by a chiral external source with either transverse spin angular momentum or transverse phase vortex, robust light flow propagating along opposite directions is observed in several kinds of sharp-turn interfaces between two topologically-distinct silicon photonic crystals. A transverse orbital angular momentum mode with alternating phase vortex exists at the boundary of two such photonic crystals. In addition, unidirectional transport is robust to the working frequency even when the ring size or location of the pseudo-spin source varies in a certain range, leading to the superiority of the broadband photonic device. These findings enable one to make use of transverse angular momentum, a kind of degree of freedom, to achieve unidirectional robust transport in the telecom region and other potential applications in integrated photonic circuits, such as on-chip robust delay lines.

  5. Angular distribution of oriented nucleus fission neutrons

    International Nuclear Information System (INIS)

    Barabanov, A.L.; Grechukhin, D.P.

    1982-01-01

    Calculations of anisotropy of angular distribution of oriented 235 U nuclei thermal fission neutrons have been carried out. the neutrons were assumed to evaporate isotropically by completely accelerated fragements in the fragment system with only its small part, i. e. fission-producing neutrons, emitted at the moment of neck break. It has been found out that at low energies of neutrons Esub(n)=1-2 MeV the sensitivity of the angular distribution anisotropy to variations of spectrum of neutron evaporation from fragments and the magnitude of a share of fission-producing neutrons reaches approximately 100%, which at high energies, Esub(n) > 5 MeV it does not exceed approximately 20%. Therefore the angular distribution of fast neutrons to a greater degree of confidence may be used for restoring the angular distribution anisotropy of fragments while the angular distribution of low energy neutrons may be used for deriving information on the fission process, but only in case 6f the experiment accuracy is better than approximately 3%

  6. The Effect of Media on Preservice Science Teachers' Attitudes toward Astronomy and Achievement in Astronomy Class

    Science.gov (United States)

    Bektasli, Behzat

    2013-01-01

    Studies show that it is hard to change students' attitudes toward science. This study specifically explored if media affect preservice science teachers' attitudes toward astronomy and their astronomy achievement. The sample for the pilot study consisted of 196 preservice science and mathematics teachers for attitude assessment and 230 preservice…

  7. Angular Spectral Analysis and Lowpass Filtering of Aeromagnetic ...

    African Journals Online (AJOL)

    Total-field aeromagnetic data over the western half of the Bornu basin and its surrounding areas were analyzed using angular spectral analysis, upward continuation and lowpass filtering techniques. Results revealed several angular spectral peaks at various angular orientations. The angular orientations correlated with the ...

  8. Data-oriented development with AngularJS

    CERN Document Server

    Waikar, Manoj

    2015-01-01

    This book helps beginner-level AngularJS developers organize AngularJS applications by discussing important AngularJS concepts and best practices. If you are an experienced AngularJS developer but haven't written directives or haven't created custom HTML controls before, then this book is ideal for you.

  9. New Trends in Astronomy Education: a ``Mapping" Strategy in Teaching and Learning Astronomy

    Science.gov (United States)

    Gulyaev, S.

    2003-05-01

    The application of a concept of educational ``science maps" to astronomy education is discussed. By analogy with geographical maps, scales of educational science maps -- scales of integration -- are introduced. In astronomy education, scale A represents the level of branches and fields of astronomy and astrophysics, where interconnections between various astronomical disciplines are shown. Scale B represents the level of hypotheses and theories, encompassing a significant segment of a field of astronomy. Scale C represents the level of structures and internal hierarchies, encompassing the ``geography" and ``anatomy" of the material systems and objects essential for a given astronomical discipline, as well as the principal notions and concepts it uses. Science maps of different scales are illustrated with initial examples exploring the application of this methodology in astronomy and astrophysics.

  10. Archaeo- and Cultural Astronomy in Armenia

    Science.gov (United States)

    Farmanyan, Sona V.; Mickaelian, Areg M.

    2015-08-01

    We present a general overview on Armenian Archaeoastronomy and Astronomy in Culture to mention and summarize some activities and related organizations involved. Armenia is rather rich in archaeoastronomy and culture, including calendars, rock art, mythology, etc. Archaeoastronomical issues in Armenia include: Zodiac Constellations (believed to be introduced for the first time in the Armenian Highland); Ancient Observatories; Armenian Rock Art; Ancient Armenian Calendar and other (medieval) calendars; Astronomical Terms and Names; Records of Astronomical Events by ancient Armenians; Anania Shirakatsi’s (612-685) Astronomical Heritage; Medieval Sky Maps and Astronomical Devices. During the recent years, we have organized a number of meetings, where archaeoastronomy was involved: Joint European and National Astronomy Meeting (JENAM-2007), Special Session #6: “Archaeoastronomy” (2007), ArAS VIII Annual Meeting “Astronomy and Society”, Session “Archaeoastronomy” (2009), Archaeoastronomical meeting “Astronomical Heritage in the National Culture” dedicated to Anania Shirakatsi’s 1400th anniversary (2012), Meeting “Relation of Astronomy to other Sciences, Culture and Society” (RASCS), Sessions“Archaeoastronomy” and “Astronomy in Culture” (2014). Along with Byurakan Astrophysical Observatory (BAO), there are several other institutions related to Archaeoastronomy and Astronomy in Culture: Institute of History, Institute of Archaeology and Ethnography, Institute of Literature, Institute of Language, Matenadaran (Institute of Ancient Manuscripts). We have introduced a section “Archaeoastronomy and Astronomy in Culture” in the newsletter of Armenian Astronomical Society (ArAS). This is to strengthen ArAS activities and to widen our knowledge in this area, to encourage and establish collaborations with other scientists related to these subjects; historians, archaeologists, ethnographers, philologists, linguists, artists and other

  11. Documenting the Vocabulary of Astronomy Communication

    Science.gov (United States)

    Miller, Scott; Parrish, M.; Gay, P. L.

    2008-05-01

    Learning astronomy can be a life-long process, with the seeds of knowledge planted in K-12 classes blossoming in elective college courses to create adults who actively acquire astronomy content. One of the goals of many astronomy 101 courses is to prepare students to be intelligent consumers of mainstream astronomy content, including magazine articles, popular books, and online news. To meet this goal, astronomy educators need to understand what content is being presented in the media and what level vocabulary is being used. The most simplistic way to address this problem is to examine the topics covered and vocabulary used in mainstream astronomy blogs and news feeds. In this study we looked at a selection of prominent blogs and news feeds and we present a statistical study of the frequency different scientific terms are used and topics are addressed. To make this study possible, software to read in RSS feeds was created. This software had to meet the following design specifications: runs in a reasonable amount of time, removes all XML and HTML code from text, sees words with different capitalizations as the same word, ignores end of sentence or phrase punctuation without ignoring hyphens, and has an editable list of "common English words.” This code will be available after the conference at http://www.starstryder.com. Results of this study find that many of the primary topics of Astronomy 101 classes, such as the HR Diagram, are rarely mentioned in blogs and online news, while often de-emphasized topics, such as extra solar planets, cosmology, and high energy astrophysics, show up regularly.

  12. A Pilot Astronomy Outreach Project in Bangladesh

    Science.gov (United States)

    Bhattacharya, Dipen; Mridha, Shahjahan; Afroz, Maqsuda

    2015-08-01

    In its strategic planning for the "Astronomy for Development Project," the International Astronomical Union (IAU) has ecognized, among other important missions, the role of astronomy in understanding the far-reaching possibilities for promoting global tolerance and citizenship. Furthermore, astronomy is deemed inspirational for careers in science and technology. The "Pilot Astronomy Outreach Project in Bangladesh"--the first of its kind in the country--aspires to fulfill these missions. As Bangladesh lacks resources to promote astronomy education in universities and schools, the role of disseminating astronomy education to the greater community falls on citizen science organizations. One such group, Anushandhitshu Chokro (AChokro) Science Organization, has been carrying out a successful public outreach program since 1975. Among its documented public events, AChokro organized a total solar eclipse campaign in Bangladesh in 2009, at which 15,000 people were assembled in a single open venue for the eclipse observation. The organization has actively pursued astronomy outreach to dispel public misconceptions about astronomical phenomena and to promote science. AChokro is currently working to build an observatory and Science Outreach Center around a recently-acquired 14-inch Scmidt-Cassegrain telescope and a soon-to-be-acquired new 16-inch reflector, all funded by private donations. The telescopes will be fitted with photometers, spectrometers, and digital and CCD cameras to pursue observations that would include sun spot and solar magnetic fields, planetary surfaces, asteroid search, variable stars and supernovae. The Center will be integrated with schools, colleges, and community groups for regular observation and small-scale research. Special educational and observing sessions for adults will also be organized. Updates on the development of the Center, which is expected to be functioning by the end of 2015, will be shared and feedback invited on the fostering of

  13. UV astronomy throughout the ages: a historical perspective

    Science.gov (United States)

    Linsky, Jeffrey L.

    2018-05-01

    Astronomers have long recognized the critical need for ultraviolet imaging, photometry and spectroscopy of stars, planets, and galaxies, but this need could not be satisfied without access to space and the development of efficient instrumentation. When UV measurements became feasible, first with rockets and then with satellites, major discoveries came rapidly. It is true in the UV spectral region as in all others, that significant increases in sensitivity, spectral resolution, and time domain coverage have led to significant new understanding of astrophysical phenomena. I will describe a selection of these discoveries made in each of three eras: (1) the early history of rocket instrumentation and Copernicus, the first UV satellite, (2) the discovery phase pioneered by the IUE, FUSE and EUVE satellites, and (3) the full flowering of UV astronomy with the successful operation of HST and its many instruments. I will also mention a few areas where future UV instrumentation could lead to new discoveries. This review concentrates on developments in stellar and interstellar UV spectroscopy; the major discoveries in galactic, extragalactic, and solar system research are beyond the scope of this review. The important topic of UV technologies and detectors, which enable the remarkable advances in UV astronomy are also not included in this review.

  14. Angular correlations and high energy evolution

    International Nuclear Information System (INIS)

    Kovner, Alex; Lublinsky, Michael

    2011-01-01

    We address the question of to what extent JIMWLK evolution is capable of taking into account angular correlations in a high energy hadronic wave function. Our conclusion is that angular (and indeed other) correlations in the wave function cannot be reliably calculated without taking into account Pomeron loops in the evolution. As an example we study numerically the energy evolution of angular correlations between dipole scattering amplitudes in the framework of the large N c approximation to JIMWLK evolution (the 'projectile dipole model'). Target correlations are introduced via averaging over an (isotropic) ensemble of anisotropic initial conditions. We find that correlations disappear very quickly with rapidity even inside the saturation radius. This is in accordance with our physical picture of JIMWLK evolution. The actual correlations inside the saturation radius in the target QCD wave function, on the other hand, should remain sizable at any rapidity.

  15. [Mathematics - astronomy - astrology special library].

    Science.gov (United States)

    Gluch, Sibylle

    2011-01-01

    About 1560 Elector August of Saxony created an unusual library--one distinguished within its period by both its specialization and location. Situated within the Kunstkammer this library was mostly dedicated to the mathematical sciences and related disciplines. It contained works by the most important authors on mathematics, astronomy, and astrology from the classical, medieval, and early modern periods. This essay traces the formation and composition of August's library, and examines its function: What kind of relationship existed between the library and the Kunstkammer? In what way did the library mirror the interests of the Elector, and to what extend does it permit inferences regarding the Elector's knowledge of mathematics? From the analysis August emerges not as a specialist with a deep understanding of mathematics, but as a particular aficionado of mathematical applications. As a practitioner and general follower of the mathematical arts he took part in a far-reaching intellectual network the center of which lay in the University of Wittenberg. Here, Melanchthon had effectively strengthened the importance of the mathematical disciplines within the university curriculum. He regarded mathematics as the foremost science, arguing that before all other disciplines its method enabled man to recognize the harmonic order of the world, and to discern divine providence. Thus, mathematics offered consoling stability and support in an often seemingly chaotic world torn by religious controversies. This kind of esteem for the mathematical sciences did not presuppose expert knowledge. Hence, the fact that August does not appear to have read the mathematical books he collected does not come as a contradiction. On the contrary, for August it sufficed to recognize the potential of the mathematical sciences, which he brought into life through the creation of a specialized library that developed a rhetoric of its own. The collection of his Kunstkammer library spoke of a

  16. The Canadian Astronomy Data Centre

    Science.gov (United States)

    Ball, Nicholas M.; Schade, D.; Astronomy Data Centre, Canadian

    2011-01-01

    The Canadian Astronomy Data Centre (CADC) is the world's largest astronomical data center, holding over 0.5 Petabytes of information, and serving nearly 3000 astronomers worldwide. Its current data collections include BLAST, CFHT, CGPS, FUSE, Gemini, HST, JCMT, MACHO, MOST, and numerous other archives and services. It provides extensive data archiving, curation, and processing expertise, via projects such as MegaPipe, and enables substantial day-to-day collaboration between resident astronomers and computer specialists. It is a stable, powerful, persistent, and properly supported environment for the storage and processing of large volumes of data, a condition that is now absolutely vital for their science potential to be exploited by the community. Through initiatives such as the Common Archive Observation Model (CAOM), the Canadian Virtual Observatory (CVO), and the Canadian Advanced Network for Astronomical Research (CANFAR), the CADC is at the global forefront of advancing astronomical research through improved data services. The CAOM aims to provide homogeneous data access, and hence viable interoperability between a potentially unlimited number of different data collections, at many wavelengths. It is active in the definition of numerous emerging standards within the International Virtual Observatory, and several datasets are already available. The CANFAR project is an initiative to make cloud computing for storage and data-intensive processing available to the community. It does this via a Virtual Machine environment that is equivalent to managing a local desktop. Several groups are already processing science data. CADC is also at the forefront of advanced astronomical data analysis, driven by the science requirements of astronomers both locally and further afield. The emergence of 'Astroinformatics' promises to provide not only utility items like object classifications, but to directly enable new science by accessing previously undiscovered or intractable

  17. Assessing NASE Professional Development in Astronomy Workshops

    Science.gov (United States)

    Deustua, Susana E.; Garcia, Beatriz; Ros, Rosa M.

    2016-01-01

    Since 2009, the Network for Astronomy School Education (NASE) has held 55+ workshops in countries in Asia, Africa, Europe and Latin America, training more than 1200 teachers and potentially reaching one million or more students. Like most modern professional development programs, NASE's emphasis is on interactive, hands-on learning. However, our emphasis is on "low-tech" tools that are readily available, and, inexpensive. Teachers are led through a series of activities that cover a wide range of topics in astronomy, more or less equivalent to that covered in the typical 1st year astronomy course in US colleges.In 2014 we adopted the Astronomy Diagnostic Test as pre- and post- workshop tests to gauge the change in teachers' knowledge as a result of participation in this intervention. We chose the ADT because it is a reliable and validated instrument and is available in Spanish. In this paper we discuss our results using the Astronomy Diagnostic Test 2.0 in several countries.

  18. Bibliographic Resources for the Historian of Astronomy

    Science.gov (United States)

    Corbin, B. G.

    1999-12-01

    Many large library collections now have online bibliographic catalogs on the web. These provide many hidden resources for the historian of astronomy. Special searching techniques will allow the historian to scan bibliographic records of hundreds of entries relating to biographies of astronomers, collected works of astronomers, ancient and medieval astronomy and many other historical subjects. Abstract databases such as the Astrophysics Data System and ARIBIB are also adding much historical bibliographic information. ARIBIB will eventually contain scanned images of the Astronomischer Jahresbericht containing bibliographic entries for all literature of astronomy from 1899 to 1968 and Astronomy and Astrophysics Abstracts from 1969 to present. Commercial services such as UnCover and FirstSearch provide a means of reaching bibliographic entries for journal and book literature in the history of astronomy which were not easily located in the past. A broad overview of these collections and services will be given, and searching techniques for finding ``hidden" bibliographic data will be presented. Web page addresses will be given for all sources covered.

  19. The New Bosnian Textbook of Astronomy

    Science.gov (United States)

    Muminovic, Muhamed

    MrDuring last year a new astronomical textbook under title ""ASTRONOMY"" has been prepared. In this book I have tried to keep the spirit of my previous editions started 1972. with first ever printed text on general astronomy in Bosnia-Herzegovina. After five editions the sixth one is a totaly new book. In comparation with fifth edition text of the new Astronomy is not drasticaly changed. But using computer graphics especially computer air brush technics (made by bosnian artist Mr. O. Pavlovic) I think that we produced something new in line of similar leading astronomical textbook in the world. Explantions of some astronomical phenomena who can't be described so easy by words or we are not in position to have direct images of them are much easier when you have color paintings. The new textbook and used approaches can be interesting for others who are involved in astronomical teaching and popularization. Also ASTRONOMY"" will be important step forward looking present situation in astronomy in Bosnia-Herzegovina.

  20. Characteristics of the telescope for high energy gamma-ray astronomy selected for definition studies on the Gamma Ray Observatory

    Science.gov (United States)

    Hughes, E. B.; Hofstadter, R.; Rolfe, J.; Johansson, A.; Bertsch, D. L.; Cruickshank, W. J.; Ehrmann, C. H.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.

    1980-01-01

    The high energy gamma-ray telescope selected for definition studies on the Gamma Ray Observatory provides a substantial improvement in observational capability over earlier instruments. It will have about 20 times more sensitivity, cover a much broader energy range, have considerably better energy resolution and provide a significantly improved angular resolution. The design and performance are described.

  1. Control of Rotational Energy and Angular Momentum Orientation with an Optical Centrifuge

    Science.gov (United States)

    Ogden, Hannah M.; Murray, Matthew J.; Mullin, Amy S.

    2017-04-01

    We use an optical centrifuge to trap and spin molecules to an angular frequency of 30 THz with oriented angular momenta and extremely high rotational energy and then investigate their subsequent collision dynamics with transient high resolution IR spectroscopy. The optical centrifuge is formed by combining oppositely-chirped pulses of 800 nm light, and overlapping them spatially and temporally. Polarization-sensitive Doppler-broadened line profiles characterize the anisotropic kinetic energy release of the super rotor molecules, showing that they behave like molecular gyroscopes. Studies are reported for collisions of CO2 super rotors with CO2, He and Ar. These studies reveal how mass, velocity and rotational adiabaticity impact the angular momentum relaxation and reorientation. Quantum scattering calculations provide insight into the J-specific collision cross sections that control the relaxation. NSF-CHE 105 8721.

  2. The ASTRO-H (Hitomi) X-Ray Astronomy Satellite

    Science.gov (United States)

    Takahashi, Tadayuki; Kokubun, Motohide; Mitsuda, Kazuhisa; Kelley, Richard; Ohashi, Takaya; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steve; Anabuki, Naohisa; hide

    2016-01-01

    The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E greater than 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. After a successful launch on 2016 February 17, the spacecraft lost its function on 2016 March 26, but the commissioning phase for about a month provided valuable information on the on-board instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.

  3. Time-Domain Astronomy with the Fermi GBM

    Science.gov (United States)

    Hui, C. M.

    2017-01-01

    The Fermi Gamma-ray Burst Monitor (GBM) is an all-sky monitoring instrument sensitive to energies from 8 keV to 40 MeV. Over the past 8 years of operation, the GBM has detected over 240 gamma-ray bursts per year and provided timely GCN notices with localization to few-degree accuracy for follow-up observations. In addition to GRBs, Galactic transients, solar flares, and terrestrial gamma-ray flashes have also been observed. In recent years we have also been searching the continuous GBM data for electromagnetic counterpart to astrophysical neutrinos and gravitational wave events, as these are believed to be associated with gamma-ray bursts. With continuous data downlink every few hours and a temporal resolution of 2 microseconds, GBM is well suited for observing transients and supporting EM follow-up in the era of multi-messenger astronomy.

  4. Integrated spectral study of small angular diameter galactic open clusters

    Science.gov (United States)

    Clariá, J. J.; Ahumada, A. V.; Bica, E.; Pavani, D. B.; Parisi, M. C.

    2017-10-01

    This paper presents flux-calibrated integrated spectra obtained at Complejo Astronómico El Leoncito (CASLEO, Argentina) for a sample of 9 Galactic open clusters of small angular diameter. The spectra cover the optical range (3800-6800 Å), with a resolution of ˜14 Å. With one exception (Ruprecht 158), the selected clusters are projected into the fourth Galactic quadrant (282o evaluate their membership status. The current cluster sample complements that of 46 open clusters previously studied by our group in an effort to gather a spectral library with several clusters per age bin. The cluster spectral library that we have been building is an important tool to tie studies of resolved and unresolved stellar content.

  5. Highschool astronomy research workshop in Thailand and how it transforms Thai astronomy education

    Science.gov (United States)

    Tangmatitham, Matipon

    2017-01-01

    The National Astronomical Research Institute of Thailand (NARIT) have launched the program "Advance Teacher Training Workshop" that aims to introduce both the students and astronomy teacher alike to the nature of critical thinking in science via hands on experience in astronomy projects. Students and accompanying teachers are participated in 5 days workshop in which each of them must select an individual astronomy research project. The project is then carried out on their own for the next 6 months, after which their works are presented in a conference. Progress is monitored and extra aid is delivered as needed via the use of social media. Over a hundred projects have been completed under this program. Follow up study have suggests that this workshop has shown to be quite successful at improving critical thinking skills in participants. As the program became more popular, other schools began to follow. To support the growing interest, we have also launched the "Thai Astronomical Society: student session", a highschool astronomy conference for anyone who participated or interested in astronomy related projects. Via these stages we are able to secure a permanent foothold in Thai astronomy education and inspire new generations to participate in astronomy projects.

  6. Angular and linear momentum of excited ferromagnets

    NARCIS (Netherlands)

    Yan, P.; Kamra, A.; Cao, Y.; Bauer, G.E.W.

    2013-01-01

    The angular momentum vector of a Heisenberg ferromagnet with isotropic exchange interaction is conserved, while under uniaxial crystalline anisotropy the projection of the total spin along the easy axis is a constant of motion. Using Noether's theorem, we prove that these conservation laws persist

  7. Angular distribution in ternary cold fission

    International Nuclear Information System (INIS)

    Delion, D.S.; J.W. Goethe Univ., Frankfurt; Sandulescu, A.; J.W. Goethe Univ., Frankfurt; Greiner, W.

    2003-01-01

    We describe the spontaneous ternary cold fission of 252 Cf, accompanied by 4 He, 10 Be and 14 C. The light cluster decays from the first resonant eigenstate in the Coulomb potential plus a harmonic oscillator potential. We have shown that the angular distribution of the emitted light particle is strongly connected with its deformation and the equatorial distance. (author)

  8. Probabilistic calculation for angular dependence collision

    International Nuclear Information System (INIS)

    Villarino, E.A.

    1990-01-01

    This collision probabilistic method is broadly used in cylindrical geometry (in one- or two-dimensions). It constitutes a powerful tool for the heterogeneous Response Method where, the coupling current is of the cosine type, that is, without angular dependence at azimuthal angle θ and proportional to μ (cosine of the θ polar angle). (Author) [es

  9. Heteromodal conceptual processing in the angular gyrus.

    Science.gov (United States)

    Bonner, Michael F; Peelle, Jonathan E; Cook, Philip A; Grossman, Murray

    2013-05-01

    Concepts bind together the features commonly associated with objects and events to form networks in long-term semantic memory. These conceptual networks are the basis of human knowledge and underlie perception, imagination, and the ability to communicate about experiences and the contents of the environment. Although it is often assumed that this distributed semantic information is integrated in higher-level heteromodal association cortices, open questions remain about the role and anatomic basis of heteromodal representations in semantic memory. Here we used combined neuroimaging evidence from functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to characterize the cortical networks underlying concept representation. Using a lexical decision task, we examined the processing of concepts in four semantic categories that varied on their sensory-motor feature associations (sight, sound, manipulation, and abstract). We found that the angular gyrus was activated across all categories regardless of their modality-specific feature associations, consistent with a heteromodal account for the angular gyrus. Exploratory analyses suggested that categories with weighted sensory-motor features additionally recruited modality-specific association cortices. Furthermore, DTI tractography identified white matter tracts connecting these regions of modality-specific functional activation with the angular gyrus. These findings are consistent with a distributed semantic network that includes a heteromodal, integrative component in the angular gyrus in combination with sensory-motor feature representations in modality-specific association cortices. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. INVESTIGATION OF ANGULAR BALL BEARING WEAR

    Directory of Open Access Journals (Sweden)

    A. L. Savchenko

    2006-01-01

    Full Text Available Wearing process of balls in an angular ball bearing has been investigated in the paper. Force affecting a separator from the side of balls is determined theoretically. Wear rate may be calculated with a formula for abrasive wear while substituting numerical parameter values of the investigated ball bearing for formula symbols.

  11. Canonical three-body angular basis

    International Nuclear Information System (INIS)

    Matveenko, A.V.

    2001-01-01

    Three-body problems are basic for the quantum mechanics of molecular, atomic, or nuclear systems. We demonstrate that their variational solution for rotational states can be greatly simplified. A special choice of coordinates (hyperspherical) and of the kinematics (body-fixed coordinate frame) allows one to choose basis functions in a form that makes the angular coupling trivial. (author)

  12. Temperature and angular momentum dependence of the ...

    Indian Academy of Sciences (India)

    Temperature and angular momentum dependence of the quadrupole deformation is studied in the middle of the sd-shell for 28Si and 27Si isotopes using the spherical shell model approach. The shell model calculations have been performed using the standard universal sd-shell (USD) interaction and the canonical ...

  13. Angular momentum gated neutron evaporation studies

    International Nuclear Information System (INIS)

    Banerjee, K.; Kundu, S.; Rana, T.K.; Bhattacharya, C.; Mukherjee, G.; Gohil, M.; Meena, J.K.; Pandey, R.; Pai, H.; Dey, A.; Biswas, M.; Mukhopadhyay, S.; Pandit, D.; Pal, S.; Banerjee, S.R.; Bhattacharya, S.; Bandhopadhyay, T.

    2010-01-01

    The inverse level density parameter k (k = A/a, where A is the mass number of the compound nucleus)is investigated as a function of angular momentum by measuring γ-ray fold gated neutron evaporation spectrum in 4 He + 115 In fusion reaction using 35 MeV 4 He ion beam from VECC K130 cyclotron

  14. Angular-momentum-bearing modes in fission

    International Nuclear Information System (INIS)

    Moretto, L.G.; Peaslee, G.F.; Wozniak, G.J.

    1989-03-01

    The angular-momentum-bearing degrees of freedom involved in the fission process are identified and their influence on experimental observables is discussed. The excitation of these modes is treated in the ''thermal'' limit, and the resulting distributions of observables are calculated. Experiments demonstrating the role of these modes are presented and discussed. 61 refs., 12 figs

  15. Angular Intermittency and Analytical QCD Predictions

    CERN Document Server

    Chekanov, S.V.

    1997-01-01

    We present a comparison of local multiplicity fluctuations in angular phase-space intervals with first-order QCD predictions. The data are based on 810k hadronic events at 91.2 GeV collected with the L3 detector at LEP during 1994.

  16. Angular momentum transfer in incomplete fusion

    Indian Academy of Sciences (India)

    Keywords. Heavy-ion reactions; incomplete fusion; isomeric cross-section ratio; 12C, 16O beams; 93Nb; 89Y targets; angular momentum. ... R Tripathi1 A Goswami1. Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India; School of Studies in Physics, Vikram University, Ujjain 456 010, India ...

  17. Temperature and angular momentum dependence of the ...

    Indian Academy of Sciences (India)

    Abstract. Temperature and angular momentum dependence of the quadrupole deformation is studied in the middle of the sd-shell for 28Si and 27Si isotopes using the spherical shell model ... Department of Physics, University of Kashmir, Srinagar 190 006, India; Inter-University Accelerator Centre, New Delhi 110 067, India ...

  18. A Novel Permanent Magnetic Angular Acceleration Sensor

    Directory of Open Access Journals (Sweden)

    Hao Zhao

    2015-07-01

    Full Text Available Angular acceleration is an important parameter for status monitoring and fault diagnosis of rotary machinery. Therefore, we developed a novel permanent magnetic angular acceleration sensor, which is without rotation angle limitations and could directly measure the instantaneous angular acceleration of the rotating system. The sensor rotor only needs to be coaxially connected with the rotating system, which enables convenient sensor installation. For the cup structure of the sensor rotor, it has a relatively small rotational inertia. Due to the unique mechanical structure of the sensor, the output signal of the sensor can be directed without a slip ring, which avoids signal weakening effect. In this paper, the operating principle of the sensor is described, and simulated using finite element method. The sensitivity of the sensor is calibrated by torsional pendulum and angle sensor, yielding an experimental result of about 0.88 mV/(rad·s−2. Finally, the angular acceleration of the actual rotating system has been tested, using both a single-phase asynchronous motor and a step motor. Experimental result confirms the operating principle of the sensor and indicates that the sensor has good practicability.

  19. Astronomy Exercises for the Artist: van Gogh the Observer

    Science.gov (United States)

    Lawlor, Timothy M.

    2013-01-01

    We present a set of exercises designed to be used in a survey astronomy course, an introductory astronomy laboratory course, or in secondary education. The exercises use the great works of Vincent van Gogh but could

  20. High-energy astronomy in the U.K

    International Nuclear Information System (INIS)

    Pounds, K.A.

    1976-01-01

    Highlights of British research on radio galaxies, x-ray astronomy, and hot black holes are described. The prospects for international collaboration on space projects, in particular x-ray astronomy, are discussed

  1. Beyond the International Year of Astronomy

    Science.gov (United States)

    Owens, S.

    2010-08-01

    The International Year of Astronomy (IYA2009) is over, and we are working to build upon its legacy. Many of the projects that ran during IYA2009 have come to an end, but the networks that developed and ran them - networks of amateur and professional astronomers, science communicators, educators - are still here, passionate about continuing to engage the public with astronomy. One of my key duties as IYA2009 UK Coordinator was to support and develop these networks, and it is that support that would be most sorely missed had IYA2009 just petered out at the end of last year. Fortunately that hasn't happened, and the three main IYA2009 project partners - the Royal Astronomical Society, the Science and Technology Facilities Council, and the Institute of Physics - have been joined by two others - the Society for Popular Astronomy and the British Astronomical Association - in Beyond IYA.

  2. L'astronomie et son histoire

    CERN Document Server

    Roy, Jean-René

    1982-01-01

    Le livre de Jean-René Roy nous présente une vaste synthèse des connaissances présentes en astronomie. Le grand mérite du livre est de dérouler son sujet en parallèle avec une histoire de l'astronomie. Le côté historique est ici beaucoup plus qu'un luxe. Il redonne leurs dimensions vraies aux réponses qu'apporte l'astronomie. Pour bien sentir la nature d'une étape franchie, il faut aussi avoir vécu la situation telle qu'elle se présentait avant. Et les fiches personnelles incluses dans le livre ont l'intérêt de nous rapprocher encore plus du "" feu de l'action "". Écrit dans un style direct et

  3. Very high energy gamma-ray astronomy

    International Nuclear Information System (INIS)

    Weekes, T.C.

    1988-01-01

    Current interest in gamma-ray astronomy at energies above 100 GeV comes from the identification of Cygnus X-3 and other X-ray binaries as sources. In addition there are reports of emission from radio pulsars and a variety of other objects. The statistical significance of many of the observations is not high and many reported effects await confirmation, but there are a sufficient number of independent reports that very high energy gamma-ray astronomy must now be considered to have an observational basis. The observations are summarized with particular emphasis on those reported since 1980. The techniques used - the detection of small air showers using the secondary photons and particles at ground level - are unusual and are described. Future prospects for the field are discussed in relation to new ground-based experiments, satellite gamma-ray studies and proposed neutrino astronomy experiments. (orig.) With 296 refs

  4. The sociology of innovation in modern astronomy

    International Nuclear Information System (INIS)

    Edge, D.

    1977-01-01

    This paper describes some of the main features of the development of astronomy since 1945, stressing sociological factors, and drawing examples mainly from the history of radio astronomy. Particular attention is given to aspects which appear to distinguish astronomy from other recently-studied sciences - notably, the prevalence of serendipitous discoveries, and the lack of any general resistance from the 'parent' discipline. The work of Kuhn and Hagstrom is used to illuminate these features, and also to indicate how a sociological analysis can be advanced of individual research decisions, and of the nature of disputes within science. Common misconceptions about the nature and scope of sociology are briefly discussed; in particular, it is emphasized that the kind of sociology of science under discussion cannot be normative. (author)

  5. Ideas for Citizen Science in Astronomy

    Science.gov (United States)

    Marshall, Philip J.; Lintott, Chris J.; Fletcher, Leigh N.

    2015-08-01

    We review the expanding, internet-enabled, and rapidly evolving field of citizen astronomy, focusing on research projects in stellar, extragalactic, and planetary science that have benefited from the participation of members of the public. These volunteers contribute in various ways: making and analyzing new observations, visually classifying features in images and light curves, exploring models constrained by astronomical data sets, and initiating new scientific enquiries. The most productive citizen astronomy projects involve close collaboration between the professionals and amateurs involved and occupy scientific niches not easily filled by great observatories or machine learning methods: Citizen astronomers are motivated by being of service to science, as well as by their interest in the subject. We expect participation and productivity in citizen astronomy to increase, as data sets get larger and citizen science platforms become more efficient. Opportunities include engaging citizens in ever-more advanced analyses and facilitating citizen-led enquiry through professional tools designed with citizens in mind.

  6. Ultra-high resolution coded wavefront sensor

    KAUST Repository

    Wang, Congli

    2017-06-08

    Wavefront sensors and more general phase retrieval methods have recently attracted a lot of attention in a host of application domains, ranging from astronomy to scientific imaging and microscopy. In this paper, we introduce a new class of sensor, the Coded Wavefront Sensor, which provides high spatio-temporal resolution using a simple masked sensor under white light illumination. Specifically, we demonstrate megapixel spatial resolution and phase accuracy better than 0.1 wavelengths at reconstruction rates of 50 Hz or more, thus opening up many new applications from high-resolution adaptive optics to real-time phase retrieval in microscopy.

  7. Variation in angular velocity and angular acceleration of a particle in rectilinear motion

    International Nuclear Information System (INIS)

    Mashood, K K; Singh, V A

    2012-01-01

    We discuss the angular velocity and angular acceleration associated with a particle in rectilinear motion with constant acceleration. The discussion was motivated by an observation that students and even teachers have difficulty in ascribing rotational motion concepts to a particle when the trajectory is a straight line. We present some details of our observations. A formal derivation of ω and α is presented which reveals ‘surprising’ and non-intuitive aspects, namely non-monotonic behaviour with an associated extremum. The special case of constant velocity is studied and we find that angular acceleration associated with it also has an extremum. We discuss a plausible source of difficulty. (paper)

  8. Relation of Astronomy to other Sciences, Culture and Society

    Science.gov (United States)

    Harutyunian, H. A.; Mickaelian, A. M.; Farmanyan, S. V.

    2015-07-01

    The book contains the Proceedings of XIII Annual Meeting of the Armenian Astronomical Society "Relation of Astronomy to other Sciences, Culture and Society". It consists of 9 main sections: "Introductory", "Astronomy and Philosophy", "Astrobiology", "Space-Earth Connections", "Astrostatistics and Astroinformatics", "Astronomy and Culture, Astrolinguistics", "Archaeoastronomy", "Scientific Tourism and Scientific Journalism", and "Armenian Astronomy". The book may be interesting to astronomers, philosophers, biologists, culturologists, linguists, historians, archaeologists and to other specialists, as well as to students.

  9. The Very Large Array: Pioneering New Directions in Radio Astronomy

    Science.gov (United States)

    McKinnon, Mark

    2018-01-01

    The Very Large Array (VLA) started science operations in 1980 and was rechristened the Jansky VLA after a major upgrade to its electronics system was completed in 2012. The VLA plays a prominent role in scientific discovery through studies of the Solar System, star and planet formation, galaxy formation, and time domain astronomy. It has attained iconic status as one of the most scientifically productive telescopes on EarthIn 2017, three major initiatives were launched at the VLA with the goal of maintaining its leadership role and impact in radio astronomy in the near and long term future:1. In September, the VLA embarked upon the VLA Sky Survey (VLASS), the highest resolution survey ever undertaken at radio wavelengths. The survey was planned in consultation with the astronomy community and will be used to search for transients, study the polarization properties of extragalactic radio sources, and study highly obscured sources in our Galaxy.2. Detailed planning for a next generation VLA (ngVLA) began in earnest in 2017. The ngVLA will open a new window on the Universe through ultra-sensitive imaging of thermal line and continuum emission down to milliarcsecond resolution, as well as unprecedented broad-band continuum polarimetric imaging of non-thermal processes. A proposal for the instrument will be submitted to the 2020 Decadal Survey.3. A multi-year program to replace the 40+ year old infrastructure at the VLA site was initiated in 2017. The program includes the replacement of the VLA’s electrical infrastructure in 2018, improvements to the VLA rail system, and the replacement of heavy maintenance equipment.The VLA continued to play a major role in discovering and explaining the physics of transient phenomena in 2017, to include fast transients, such as fast radio bursts, and long time scale transients, such as novae, tidal disruption events, and gamma-ray bursts.More thorough descriptions of the VLASS and ngVLA, along with the science that can be done with

  10. Astronomy from the chair - the application of the Internet in promoting of Astronomy

    Science.gov (United States)

    Tomic, Zoran

    2014-05-01

    Internet and modern communication technologies are an indispensable part of modern life. The use of the Internet makes it possible to enhance the education and expand opportunities for acquiring new knowledge. One example is Astronomy, where today thanks to the Internet, we can control telescopes that are distant from us and listen to lectures from Universities in other countries. "Astronomy from the chair" is the name for a concept where amateur astronomers can deal with astronomy from their homes using the Internet. The concept can be divided into four sections depending on the content being offered: Robotic Observatory, Virtual Observatory, Online astronomy broadcasting and Online courses. Robotic observatory is defined as an astronomical instrument and detection system that enables efficient observation without the need of a person's physical intervention. Virtual Observatory is defined as a collection of databases and software tools that use the Internet as a platform for scientific research. Online astronomy broadcasting is part of concept "Astronomy from the chair" which gives users the opportunity to get directly involved in astronomical observation organized by an amateur astronomer from somewhere in the world. Online courses are groups of sites and organizations that provide the opportunity to amateur astronomers to attend lectures, save and watch video materials from lectures, do homework, communicate with other seminar participants and in that way become familiar with the various areas of Astronomy. This paper discusses a new concept that describes how the Internet can be applied in modern education. In this paper will be described projects that allows a large number of astronomy lovers to do their own research without the need to own a large and expensive set of astronomical equipment (Virtual Telescope from Italy, Observatory "Night Hawk" from Serbia and project "Astronomy from an armchair" at Faculty of Sciences and Mathematics in Nis), to help

  11. Some innovative programmes in Astronomy education

    Science.gov (United States)

    Babu, G. S. D.; Sujatha, S.

    In order to inculcate a systematic scientific awareness of the subject of Astronomy among the students and to motivate them to pursue careers in Astronomy and Astrophysics, various innovative educational programmes have been designed at MPBIFR. Among them, the main programme is termed as the ``100-hour Certificate Course in Astronomy and Astrophysics'' which has been designed basically for the students of the undergraduate level of B.Sc. and B.E. streams. The time duration of the 100 hours in this course is partitioned as 36 hours of classroom lectures, 34 hours of practicals and field trips and the remaining 30 hours being dedicated to dissertation writing and seminar presentations by the students. In addition, after the 100-hour course, the students have the option to take up specialized advance courses in the topics of Astrobiology, Astrochemistry, Radio Astronomy, Solar Astronomy and Cosmology as week-end classes. These courses are at the post graduate level and are covered in a span of 18 to 20 hours spread over a period of 9 to 10 weeks. As a preparatory programme, short-term introductory courses in the same subject are conducted for the high school students during the summer vacation period. Along with this, a three-week programme in basic Astronomy is also designed as an educational package for the general public. The students of these courses have the opportunity of being taken on field trips to various astronomical centers as well as the Radio, Solar and the Optical Observatories as part of their curriculum. The guided trips to the ISRO’s Satellite Centre at Bangalore and the Satellite Launching Station at SHAR provide high degree of motivation apart from giving thrilling experiences to the students. Further, the motivated students are encouraged to involve themselves in regular research programmes in Astronomy at MPBIFR for publishing research papers in national and international journals. The teaching and mentoring faculty for all these programmes

  12. An Introduction to Distance Measurement in Astronomy

    CERN Document Server

    de Grijs, Richard

    2011-01-01

    Distance determination is an essential technique in astronomy, and is briefly covered in most textbooks on astrophysics and cosmology. It is rarely covered as a coherent topic in its own right. When it is discussed the approach is frequently very dry, splitting the teaching into, for example, stars, galaxies and cosmologies, and as a consequence, books lack depth and are rarely comprehensive. Adopting a unique and engaging approach to the subject An Introduction to distance Measurement in Astronomy will take the reader on a journey from the solar neighbourhood to the edge of the Universe, dis

  13. An Assessment of Slacker Astronomy Outreach Results

    Science.gov (United States)

    Price, A.; Gay, P. L.; Searle, T.; Brissenden, G.

    2005-12-01

    Slacker Astronomy is a weekly podcast covering recent astronomical news in a humorous, irreverent manner while respecting the intelligence of the audience. This is a new approach to astronomical outreach both technically and stylistically. Using the Field-tested Learning Assessment Guide (FLAG) and the Quality Function Deployment (QFD) needs analysis survey system, we have have conducted an in-depth project to determine whether this new style is effective and what audience needs are outstanding. Slacker Astronomy currently has around 11,000 weekly listeners and was founded in February, 2005. Recordings and scripts are available to the public under the Creative Commons license at www.slackerastronomy.org.

  14. The History and Practice of Ancient Astronomy

    CERN Document Server

    Evans, James

    1998-01-01

    The History and Practice of Ancient Astronomy combines new scholarship with hands-on science to bring readers into direct contact with the work of ancient astronomers. While tracing ideas from ancient Babylon to sixteenth-century Europe, the book places its greatest emphasis on the Greek period, when astronomers developed the geometric and philosophical ideas that have determined the subsequent character of Western astronomy. The author approaches this history through the concrete details of ancient astronomical practice. Carefully organized and generously illustrated, the book can teach reade

  15. Kepler's Philosophy and the New Astronomy

    CERN Document Server

    Martens, Rhonda

    2009-01-01

    Johannes Kepler contributed importantly to every field he addressed. He changed the face of astronomy by abandoning principles that had been in place for two millennia, made important discoveries in optics and mathematics, and was an uncommonly good philosopher. Generally, however, Kepler's philosophical ideas have been dismissed as irrelevant and even detrimental to his legacy of scientific accomplishment. Here, Rhonda Martens offers the first extended study of Kepler's philosophical views and shows how those views helped him construct and justify the new astronomy.Martens notes that since Ke

  16. Advances in astronomy and astrophysics 7

    CERN Document Server

    Kopal, Zdenek

    2013-01-01

    Advances in Astronomy and Astrophysics, Volume 7 covers reviews about the advances in astronomy and astrophysics. The book presents reviews on the scattering of electrons by diatomic molecules and on Babcock's theory of the 22-year solar cycle and the latitude drift of the sunspot zone. The text then describes reviews on the structures of the terrestrial planets (Earth, Venus, Mars, Mercury) and on type III solar radio bursts. The compact and dispersed cosmic matter is also considered with regard to the search for new cosmic objects and phenomena and on the nature of the ref shift from compact

  17. Combining angular response classification and backscatter imagery segmentation for benthic biological habitat mapping

    Science.gov (United States)

    Che Hasan, Rozaimi; Ierodiaconou, Daniel; Laurenson, Laurie

    2012-01-01

    Backscatter information from multibeam echosounders (MBES) have been shown to contain useful information for the characterisation of benthic habitats. Compared to backscatter imagery, angular response of backscatter has shown advantages for feature discrimination. However its low spatial resolution inhibits the generation of fine scale habitat maps. In this study, angular backscatter response was combined with image segmentation of backscatter imagery to characterise benthic biological habitats in Discovery Bay Marine National Park, Victoria, Australia. Angular response of backscatter data from a Reson Seabat 8101 MBES (240 kHz) was integrated with georeferenced underwater video observations for constructing training data. To produce benthic habitat maps, decision tree supervised classification results were combined with mean shift image segmentation for class assignment. The results from mean angular response characteristics show effects of incidence angle at the outer angle for invertebrates (INV) and mixed red and invertebrates (MRI) classes, whilst mixed brown algae (MB) and mixed brown algae and invertebrates (MBI) showed similar responses independent from incidence angle. Automatic segmentation processing produce over segmented results but showed good discrimination between heterogeneous regions. Accuracy assessment from habitat maps produced overall accuracies of 79.6% (Kappa coefficient = 0.66) and 80.2% (Kappa coefficient = 0.67) for biota and substratum classifications respectively. MRI and MBI produced the lowest average accuracy while INV the highest. The ability to combine angular response and backscatter imagery provides an alternative approach for investigating biological information from acoustic backscatter data.

  18. Angular distribution of atoms ejected by laser ablation of different metals

    International Nuclear Information System (INIS)

    Konomi, I.; Motohiro, T.; Asaoka, T.

    2009-01-01

    Angular distributions of 13 different metals ejected by laser ablation using fourth harmonics (wavelength=266 nm) of neodymium doped yttrium aluminum garnet laser and a fluence close to near-threshold value (2.3 J/cm 2 ) have been investigated with a high angular resolution. The angular distribution which is characterized by the exponent n of cos n θ distribution showed very broad range of values between 3 and 24 for different metals. A simple relation that the exponent n is proportional to the square root of particle atomic weight as reported previously has not been observed. Instead, a general trend has been found that the metals with higher sublimation energy such as Ta and Zr show narrower angular distribution than those with lower sublimation energy such as Sn and In. While the sublimation energy of metals has a great influence on the angular distribution of ejected atoms, a simple consideration suggests that their thermal conductivity and specific heat have little effect on it.

  19. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. Shabnam Iyyani. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 30 Review. Explosive and Radio-Selected Transients: Transient Astronomy with Square Kilometre Array and its Precursors · Poonam Chandra G. C. ...

  20. Analysis of Individual "Test Of Astronomy STandards" (TOAST) Item Responses

    Science.gov (United States)

    Slater, Stephanie J.; Schleigh, Sharon Price; Stork, Debra J.

    2015-01-01

    The development of valid and reliable strategies to efficiently determine the knowledge landscape of introductory astronomy college students is an effort of great interest to the astronomy education community. This study examines individual item response rates from a widely used conceptual understanding survey, the Test Of Astronomy Standards…

  1. Division X, XII / Commission 40, 41 / Working Group Radio Astronomy

    NARCIS (Netherlands)

    Kellermann, Kenneth; Orchiston, Wayne; Davies, Rod; Gurvits, Leonid; Ishiguro, Masato; Lequeux, James; Swarup, Govind; Wall, Jasper; Wielebinski, Richard; van Woerden, Hugo

    The IAU Working Group on Historical Radio Astronomy (WGHRA) was formed at the 2003 General Assembly of the IAU as a Joint Working Group of Commissions 40 (Radio Astronomy) and 41 (History of Astronomy), in order to: a) assemble a master list of surviving historically-significant radio telescopes and

  2. NASE Training Courses in Astronomy for Teachers throughout the World

    Science.gov (United States)

    Ros, Rosa M.

    2012-01-01

    Network for Astronomy School Education, NASE, is a project that is organizing courses for teachers throughout the entire world. The main objective of the project is to prepare secondary and primary school teachers in astronomy. Students love to know more about astronomy and teachers have the opportunity to observe the sky that every school has…

  3. How, precisely, can astronomy be of benefit to anyone?

    NARCIS (Netherlands)

    Jones, Bernard J. T.; VallsGabaud, D; Boksenberg, A

    Astronomy as an observational science is technology driven both from the point of view of data, acquisition and of data processing and visualisation. Astronomy exploits a very wide base of technologies which are developed, enhanced and extended by users. Consequently, astronomy can return new and

  4. 47 CFR 2.107 - Radio astronomy station notification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy stations...

  5. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Astronomy is a very interesting subject for undergraduate students studying physics. In this paper, we report astronomy education for undergraduate students in the Physics Department of Guangzhou University, and how we are teaching astronomy to the students. Astrophysics has been rapidly developing ...

  6. Covering the Standards: Astronomy Teachers' Preparation and Beliefs

    Science.gov (United States)

    Plummer, Julia D.; Zahm, Valerie M.

    2010-01-01

    An online survey of science teachers and interviews with curriculum directors were used to investigate the coverage of astronomy in middle and high schools in the greater Philadelphia region. Our analysis looked beyond astronomy elective courses to uncover all sources of astronomy education in secondary schools. We focused on coverage of state…

  7. No Child Left Behind and High School Astronomy

    Science.gov (United States)

    Krumenaker, Larry

    2009-01-01

    Astronomy was a required subject in the first American secondary level schools, the academies of the 18th century. When these were supplanted a century later by public high schools, astronomy still was often required, subsumed into courses of Natural Philosophy. Reasons given at that time to support astronomy as a part of general education include…

  8. The decade of discovery in astronomy and astrophysics

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The conference presents papers on recommended ground- and space-based initiatives for the 1990s. The need to restore the research infrastructure at the university level is addressed as well as ways of achieving a balanced space program. Consideration is also given to science opportunities, astronomy and the computer revolution, lunar astronomy, policy opportunities, and astronomy as a national asset

  9. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy. K. G. Arun. Articles written in Journal of Astrophysics and Astronomy. Volume 37 Issue 4 December 2016 pp 30 Review. Explosive and Radio-Selected Transients: Transient Astronomy with Square Kilometre Array and its Precursors · Poonam Chandra G. C. ...

  10. Journal of Astrophysics and Astronomy | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Information for Authors. Journal of Astrophysics and Astronomy. The Journal of Astrophysics and Astronomy publishes papers on all aspects of Astrophysics and Astronomy, including instrumentation. The submission of a paper will be held to imply that it represents the results of original research not previously published; ...

  11. Development of Angular Motion, Angular Momentum, and Torque Knowledge Bases for an Intelligent Physics Tutoring System

    National Research Council Canada - National Science Library

    Eason, Michael

    1998-01-01

    .... The knowledge base developed in this project provides the physics backbone for the rest of the tutoring system by generating the necessary equations and solution graphs to solve selected angular motion...

  12. Grote Reber, Radio Astronomy Pioneer, Dies

    Science.gov (United States)

    2002-12-01

    Grote Reber, one of the earliest pioneers of radio astronomy, died in Tasmania on December 20, just two days shy of his 91st birthday. Reber was the first person to build a radio telescope dedicated to astronomy, opening up a whole new "window" on the Universe that eventually produced such landmark discoveries as quasars, pulsars and the remnant "afterglow" of the Big Bang. His self- financed experiments laid the foundation for today's advanced radio-astronomy facilities. Grote Reber Grote Reber NRAO/AUI photo "Radio astronomy has changed profoundly our understanding of the Universe and has earned the Nobel Prize for several major contributions. All radio astronomers who have followed him owe Grote Reber a deep debt for his pioneering work," said Dr. Fred Lo, director of the National Radio Astronomy Observatory (NRAO). "Reber was the first to systematically study the sky by observing something other than visible light. This gave astronomy a whole new view of the Universe. The continuing importance of new ways of looking at the Universe is emphasized by this year's Nobel Prizes in physics, which recognized scientists who pioneered X-ray and neutrino observations," Lo added. Reber was a radio engineer and avid amateur "ham" radio operator in Wheaton, Illinois, in the 1930s when he read about Karl Jansky's 1932 discovery of natural radio emissions coming from outer space. As an amateur operator, Reber had won awards and communicated with other amateurs around the world, and later wrote that he had concluded "there were no more worlds to conquer" in radio. Learning of Jansky's discovery gave Reber a whole new challenge that he attacked with vigor. Analyzing the problem as an engineer, Reber concluded that what he needed was a parabolic-dish antenna, something quite uncommon in the 1930s. In 1937, using his own funds, he constructed a 31.4-foot-diameter dish antenna in his back yard. The strange contraption attracted curious attention from his neighbors and became

  13. The Correlation between Pre-Service Science Teachers' Astronomy Achievement, Attitudes towards Astronomy and Spatial Thinking Skills

    Science.gov (United States)

    Türk, Cumhur

    2016-01-01

    The purpose of this study was to examine the changes in pre-service Science teachers' astronomy achievement, attitudes towards astronomy and skills for spatial thinking in terms of their years of study. Another purpose of the study was to find out whether there was correlation between pre-service teachers' astronomy achievement, attitudes towards…

  14. Techniques in X-ray Astronomy

    Indian Academy of Sciences (India)

    This knowledge, or energy spectrum, helps astronomers to look for and determine the. Kulinder Pal Singh is in the Department of. Astronomy and Astro- physics of the Tata. Institute of Fundamental. Research, Mumbai. His primary fields of research are X-ray studies of hot plasmas in stars, super- nova remnants, galaxies,.

  15. Astronomy Education and Teacher Training in Turkey

    Science.gov (United States)

    Kirbiyik, Halil

    In this talk, education in astronomy and space sciences in schools in Turkey as well as activities to create awareness in these subjects will be discussed. A search done among youngsters(ages from 15 to 24) for measuring the scientific literacy showed that most attractive subjects to the Turkish younsters are “internet” and “astronomy”. This result led authorities to take necessary measures to fill the gap especially in teaching material such as books. Another attempt along this is to increase astronomy subjects in the school curricula. Besides TUBITAK National Observatory, universities and Turkish Astronomical Society are giving every efort to create public awareness of space activities and space sciences. As for the teacher training in astronomy and space sciences, much has been done but no success has come yet. Astronomy subjects, in schools, are generally taught not by astronomers but some other substitutes from other branches, such as physics and mathematics. Thus the Ministry of Education prefers training teachers in service. Nevertheless it must be stated that astronomers are pushing forward to formally have the right to train astronomers to become teachers to be hired by the Ministry of Education in schools.

  16. Tactile Astronomy - a Portuguese case study

    Science.gov (United States)

    Canas, L.; Alves, F.; Correia, A.

    2012-09-01

    Although astronomy plays an important role in the most various outreach initiatives, as well as school science curricula, due to its strong visual component in knowledge acquisition, astronomy subjects are not entirely well addressed and accessed by visually impaired students and/or general public. This stresses the need of more tactile material production, still very scarce in an educational context whether formal or informal. This is a case study activity developed based on different schematic tactile images of several objects present in our solar system. These images in relief, highlight, through touch, several relevant features present in the different astronomical objects studied. The scientific knowledge is apprehended through the use of a tactile key, complemented with additional information. Through proper hands-on activities implementation and careful analysis of the outcome, the adapted images associated with an explanatory key prove to be a valuable resource in tactile astronomy domain. Here we describe the process of implementing such initiative near visually impaired students. The struggles and challenges perceived by all involved and the enrichment experience of engaging astronomy with visually impaired audiences, broadening horizons in an overall experience accessible to all.

  17. Multi-Messenger Astronomy with Gravitational Waves

    Indian Academy of Sciences (India)

    Multi-Messenger Astronomy with Gravitational Waves | LIGO-G1601377-v2. Deeper searches. • Devasthal 3.6m, Mt. Abu 2.5m. • Indian ten-meter class telescope? • SALT / other partner programs. • Thirty Meter Telescope. » A proposal for EMGW already submitted! • Radio followup: » uGMRT. » SKA. Varun Bhalerao ...

  18. History of x-ray astronomy

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. History of x-ray astronomy. Major X-ray Missions. 1970 :UHURU: detected 339 new sources (1st sky coverage). 1978: Einstein First x-ray imaging mission (>1000 sources). 1990: ROSAT; Soft X-ray imaging mission; detected 100,000 sources (deeper sky coverage) ...

  19. 3D Virtual Reality for Teaching Astronomy

    Science.gov (United States)

    Speck, Angela; Ruzhitskaya, L.; Laffey, J.; Ding, N.

    2012-01-01

    We are developing 3D virtual learning environments (VLEs) as learning materials for an undergraduate astronomy course, in which will utilize advances both in technologies available and in our understanding of the social nature of learning. These learning materials will be used to test whether such VLEs can indeed augment science learning so that it is more engaging, active, visual and effective. Our project focuses on the challenges and requirements of introductory college astronomy classes. Here we present our virtual world of the Jupiter system and how we plan to implement it to allow students to learn course material - physical laws and concepts in astronomy - while engaging them into exploration of the Jupiter's system, encouraging their imagination, curiosity, and motivation. The VLE can allow students to work individually or collaboratively. The 3D world also provides an opportunity for research in astronomy education to investigate impact of social interaction, gaming features, and use of manipulatives offered by a learning tool on students’ motivation and learning outcomes. Use of this VLE is also a valuable source for exploration of how the learners’ spatial awareness can be enhanced by working in 3D environment. We will present the Jupiter-system environment along with a preliminary study of the efficacy and usability of our Jupiter 3D VLE.

  20. Extragalactic Astronomy: The Universe Beyond Our Galaxy.

    Science.gov (United States)

    Jacobs, Kenneth Charles

    This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers of secondary school chemistry, physics, and earth science. The material is presented in three parts: one section provides the fundamental content of extragalactic astronomy, another section discusses modern discoveries in…